Chloramphenicol

Chloramphenicol
After 48 hours, the experimenter was able to obtain the Petri dish in order to observe what had taken
place, within the nutrient agar plate, of the span of this period of time. The experimenter was able to
establish that any clear areas surrounding the filter–paper disks were the zones of inhibition and they
indicated that the antibiotic was able to inhibit the bacterial growth, and any cloudy areas of the agar
demonstrated that bacterial growth was still able to take place within the given conditions. Thus, the
larger the zone of inhibition, the more bacteria was inhibited within this specific environment.
Quadrant 1 contained an Erythromycin filter–paper disk, which was able to inhibit the growth of
Bacteria D. The Erythromycin filter–paper ... Show more content on Helpwriting.net ...
First, of the other antibiotics within the rationale, Chloramphenicol was able to create the largest
zone of inhibition, with the largest radius of the other two antibiotics, and was able to fully inhibit
the growth of Kocuria rosea, without allowing any other bacterial cells to survive within the zone on
inhibition. Second, the structure of Chloramphenicol allows it to effectively inhibit the growth of
bacteria. Chloramphenicol is an antibiotic with an extremely lipid–soluble structure that allows it to
bind to the 70S ribosomes of prokaryotes and inhibit the creation of proteins, or protein synthesis,
within that prokaryote. This is able to be accomplished by the antibiotic because it is able to prevent
the peptidyl transferase activity within the ribosome, and this causes the inhibition of bacterial
growth because Peptidyl transferase is vital in the translation process of protein synthesis, a process
in which peptide bond are formed between amino acids through the use of tRNA. Therefore,
because all bacteria are unicellular organisms, the structure of Chloramphenicol allows it to be
effective against almost all bacteria, thus proving itself to be the best antibiotic to combat this strand
of bacteria. And finally, resistance towards Chloramphenicol is very minimal within bacterial
strands. High–level resistance towards Chloramphenicol can only be created through a mutation in
the 50S ribosomal subunit of a bacterial cell, which creates a gene that codes for an enzyme, known
as Chloramphenicol Acetyltransferase, which has the properties to inactivate Chloramphenicol.
However, this resistance mutation within the 50S ribosome is extremely rare and resistance towards
Chloramphenicol can be reduced if this antibiotic is used only when necessary, on patients who
absolutely need the antibiotic in order to
... Get more on HelpWriting.net ...

Lab Report On The Lab
PURPOSE/OBJECTIVE:
In this laboratory, the purpose of this lab was to allow the lab students to understand the effects of
the different antibiotics (CAM, Amp, and Strep) on the bacteria growths. This lab also allowed the
lab students to understand the importance of staining, bright–field microscopy, spectrophotometry,
and the fluorescence microscopy. The hypothesis for this lab would be that for the mixture without
the antibiotic would have an increase in the absorbance rate. The mixtures with the antibiotics
(CAM, Amp, or Strep) would affect the formation of new bacterial cells that would cause the
absorbance rate to be lowered.
DISCUSSION/CONCLUSION
In this lab, the regular media was mixed with different antibiotics: Ampicillin (Amp),
Chloramphenicol (CAM), and Strep (Streptomycin). The LB media was used as a control. The
bacteria that was used in this lab was E. Coli. E. Coli was easy to be used and it have a high
doubling time. We used the spectrophotometer to obtain the absorbance readings for Culture A to C.
For Culture D, we got the data from another group. The starter culture in the flask, the media was
cloudy, but the turbidity of the bacterial culture was still visible. With our absorbance readings for
Culture A to D, we have to convert it to the number of cells by using the formula: (1 x 〖10〗
^8)/absorbance_(t=o) x absorbance=# of cells. Each of the antibiotics caused different bacterial
growth trends to occur. The lab students get to use the Bright–field

Chloramphenicol Essay
Scott and colleagues conducted study in 1965 to further define the toxicity of chloramphenicol, a
drug which has clinical advantages as an antibiotic1. Furthermore, Chloramphenicol is known to
cause aplastic anemia – a form of bone–marrow depression – which has extended morbidity and
high mortality1. From administering various doses of chloramphenicol to middle–aged and elderly
men, Scott et Al.'s study1 concluded a dose between 25 to 30 mg. prevents the onset of detrimental
side effects of chloramphenicol. Despite Scott et Al.'s contribution to science, the study method
would not be considered ethical today by the Tri–Council Policy Statement 2 (TCPS2) guidelines
with specific violations pertaining to consent and core principles. Moreover, Scott et Al.'s study
shares similarities with the Tuskegee Syphilis Study, emphasizing how guidelines are necessary to
prevent history from repeating. The TCPS2 is employed to guarantee the fair treatment of human
participants and the ... Show more content on Helpwriting.net ...
Involvement of human subjects is vital to the advancement of scientific study, however, without
understanding or implementing bioethics studies risk repeating the atrocities done prior to the
creation or reformation of guidelines. When Scott et al. completed their study on chloramphenicol,
another ongoing study on African–American men in Tuskegee was occurring. The participants in the
Tuskegee experiment had syphilis and were under the impression they were being treated for "bad
blood", but were denied penicillin regardless of proof penicillin treated syphilis4. Tuskegee
experiments and Scott et al.'s study used unethical means to understand qualities of disease and
medicine; syphilis and chloramphenicol, respectively. In the Tuskegee experiments informed
consent was absent, moreover, participants were coerced to join the study under the false pretense of
receiving

E. Coli : Factors For Source Of Water And Place
4.4 detection of diarrheagenic E. coli virulence factors isolate according to source of water and
place. The diarrheagenic E. coli virulence factors distribution according to the source of water and
place is showed in table 4–1 and 4–2, the high frequency of virulence factors is IPaH 15 (32.6%) in
tap water, a high frequency of IPaH 19 (30.4%) in houses.
Table 4–1: The presence of virulence factors from E. coli isolates according to source of water.
Source AggR Stx IPaH eae Total + + + +
Tap water 11
(23.9%) 5
(10.8%) 15
(23.6%) 0
(0.0%) 31
(67.3%)
Cooler 3
(6.5%) 0
(0.0%) 4
(8.7%) 0
(0.0%) 7
(15.2%)
Tank 0
(0.0%) 0
(0.0%) 0
(0.0%) 0
(0.0%) 0
(0.0%)
Total 14
(30.4%) 5
(10.09%) 19
(41.3%) 46
(100.0%) 38
(82.6%)
Key: + positive ... Show more content on Helpwriting.net ...
Table 4–4: The activity of antibiotics on E. coli isolated from drinking water.
Antibiotics Sensitive Resistance Intermediate Total
Chloramphenicol 31

(67.4%) 8
(17.4%) 7
(15.2%) 46
(100%)
Ceftriaxone 29
(63.0%) 4
(8.7%) 13
(28.3%) 46
(100%)
Ciprofloxacin 24
(52.2%) 11
(23.9%) 11
(23.9%) 46
(100%)
Gentamicin 19
(41.3%) 11
(23.9%) 16
(34.8%) 46
(100%)
Tetracycline 1
(2.2%) 45
(97.8%) 0
(0.0%) 46
(100%)
4.7 The correlation between the antimicrobial susceptibility and presence of virulence factors. There
was significant correlation (p–value> 0.05(; between the presence of the Stx gene and sensitivity to
Ciprofloxacin, between the presences of IPaH gene and sensitivity to Ceftriaxone and between the
presences of Stx gene and the sensitive to Tetracycline (p–value> 0.05( as shown in table 4–5.
Table 4–5: The correlation between the antimicrobial susceptibility and the presence of virulence
factors of E. coli.
Spearman 's rho AggR Stx IPaH eae
Ciprofloxacin 0.105 0.317* –0.140 0.105 0.486 0.032 0.352 0.486
Chloramphenicol 0.032 0.238 –0.253 . 0.832 0.111 0.090 .
Ceftriaxone 0.115 0.262 0.377** . 0.447 0.078 0.010 .
Gentamicin 0.217 0.219 –0.171 . 0.148 0.143 0.257 .
Tetracycline 0.225 0.427** –0.125 . 0.132 0.003 0.408 . *Correlation is significant at P. value ≤ 0.05
**Correlation is significant at P. value ≤ 0.01
4–7

Pathogens: The Five Types Of Meningitis
Meningitis is inflammation of the meninges of the brain and/or spinal cord. There are five types of
meningitis: bacterial, viral, fungal, parasitic, and non–infectious. Meningitis is more often seen in
children and acute bacterial meningitis can be fatal if not treated in the early stages. Five types of
pathogens – E. coli, Streptococcus pneumoniae, Staphylococcus epidermidis, Haemophilus
influenza type b and group b streptococcus – have previously been reported as the top causes of
meningitis. From January 2012 through December 2015, 3mL samples of cerebrospinal fluid (CSF)
from 179 children (120 males, 59 females) ranging in age from three days old to 12 years old, with
acute bacterial meningitis, were tested and studied for antibiotic susceptibilities of CSF pathogens.
... Show more content on Helpwriting.net ...
CSF was tested in all patients to determine the pathogen(s) responsible for onset. The most isolated
organism in children three days old to three months old was E. coli (51.3%), whereas in children
three months old to 12 years old, the most isolated organism was Streptococcus pneumoniae
(23.3%). "Susceptibility testing was performed using the disc diffusion method". "All culture plates
were incubated at 37 degrees Celsius for 24–48 hours in a 5% carbon dioxide environment and at
room temperature for bacterial organisms,

The Prevalence Of E. Coli
4– Results
4.1The prevalence of E. coli isolates according to a source of water The results showed that there
was a high frequency of E. coli isolates in tap water 40/46 (86.9%) and low frequency of isolates in
Tank 1/46 (2.2%) as showed in figure 4–1. Figure 4–1: The prevalence of E. coli isolates according
to a source of water.
4.2 The prevalence of E. coli isolates according to the place
The results showed that there was a high frequency of isolates from houses 36/46 (78.3%) followed
by dormitory (15.2%) and (2.2%) from pharmacy, company and cafeteria in figure 4–2.
Figure 4–2: The prevalence of E. coli isolates according to the place.
4.3. The prevalence of E. coli isolates according to the ward and the province ... Show more content
on Helpwriting.net ...
coli virulence factor isolate according to ward and province. The diarrheagenic E. coli virulence
factors are distributed according to the ward and province as shown in table 4–3, there is a high
frequency of IPaH gene 9 (19.6%) in ward as same as in province 9 (19.6%).
Table 4–3: The presence of virulence factors of E. coli isolates according to the ward.
Source AggR Stx IPaH eae total + + + +
Khartoum 6
(13.0%) 3
(6.5%) 9
(19.6%) 0
(0.00%)
18
(39.1%)
Omdurman 5
(10.9%) 0
(0.00%) 7
(15.2%) 0
(0.00%)
12
(26.0%)
Bahri 3
(6.5%) 2

(4.3%) 3
(6.5%) 0
(0.00%)
8
(17.3%)
Total 14
(30.4%) 5
(10.9%) 19
(41.3%) 0
(0.00%)
38
(82.6%)
Key: + positive
4.6 Antimicrobial susceptibility of diarrheagenic E. coli isolated from drinking water samples Table
4–4 showed antimicrobial susceptibility patterns of diarrheagenic E. coli isolated from drinking
water. 67.4% of them were sensitive to Chloramphenicol, (63%) to Ceftriaxone, (52.2%) to
Ciprofloxacin and (41.3%) to Gentamicin with high resistance rate to Tetracycline 97.8%. Table 4–
4: The activity of antibiotics on E. coli isolated from drinking water.
Antibiotics Sensitive Resistance Intermediate Total
Chloramphenicol 31
(67.4%) 8
(17.4%) 7
(15.2%) 46
(100%)
Ceftriaxone 29
(63.0%) 4
(8.7%) 13
(28.3%) 46
(100%)
Ciprofloxacin 24
(52.2%) 11
(23.9%) 11
(23.9%) 46

Control By Antibiotics And Antiseptics Lab Report
Control by Antibiotics and Antiseptics Lab Report
Georgia State University
Introduction
The fact that each bacterial species, and even some of their respective strains, responds uniquely to a
given antimicrobial makes it necessary to have methods, which provide researchers and clinicians
with measurable susceptibilities. This need has become prevalent since the rising of later
generations of antimicrobial compounds achieved by chemical modifications of the naturally
occurring antibiotics. By utilizing the Kirby–Bauer method, researchers and clinicians are able to
determine the susceptibility of given microorganisms to different antibiotics and antimicrobials.
While antibiotics specifically target bacteria, antimicrobials cast a ... Show more content on
Helpwriting.net ...
Betadine is an idophor, which is used most frequently as an antiseptic and its exact mechanism is
still unclear. Glycerol is a sugar alcohol that is often used in soap–making. While glycerol does have
some antiseptic properties, it is primarily used for preservation or as a sweetener. Lastly hydrogen
peroxide is used for the debridement of wounds because it creates free radicals, which damage the
organic compounds. Because antimicrobials often have a more generalized effect, we expected the
results to be more consistent than the antibiotics, but still varied.
Methods
In order to observe the different effects of antibiotics and antimicrobials on different bacterial
cultures, we utilized the Kirby–Bauer method. With four different bacterial species and two plates
for each, one to test antibiotics and the other to test antimicrobials, we created lawns on each plate
with the respective bacteria. Before creating the lawns, one must label each plate to indicate the
sample, the method, and the types of antibiotics or antimicrobials used. To create a lawn, one
sterilizes an inoculating loop with an open flame, allows it to cool, dips it into the sample, and then
proceeds to create a dense zig–zag pattern that covers the area of the plate in one direction. Then the
plate is rotated 45 degrees and the process is repeated. Finally the plate is rotated 45 degrees once
more and the process is repeated again. The creation of a

Essay on Hearts R Us Preferred Stock Classification Solution
Read and Download PDF File Hearts R Us Preferred Stock Classification Solution
HEARTS R US PREFERRED STOCK CLASSIFICATION
SOLUTION
Download: HEARTS R US PREFERRED STOCK CLASSIFICATION SOLUTION PDF
There are many free Hearts R Us Preferred Stock Classification Solution that are continually
composed and archived in our online collection. If you want Hearts R Us Preferred Stock
Classification Solution that will please your research paper requires, then you put on not should to
worry about that to get long. This is considering that there is a substantial database of numerous
compositions as well as term paper remedies to obtain school students.
You will certainly locate that you in fact do not need to write the Hearts R Us Preferred Stock ...
Show more content on Helpwriting.net ...
There are many Ebooks available in our online library related with E15–2 Recording The Issuance
Of
Common And Preferred Stock) ......
[PDF]
HEARTS R US SOLUTION
http://pdfebookcenter.com/file/hearts–r–us–solution.pdf
Format: PDF Documents
Status: Available
Read online and download Hearts R Us Solution. There are many Ebooks available in our online
library related with Hearts R Us Solution ......
PDF File: Hearts R Us Preferred Stock Classification Solution
2
Read and Download PDF File Hearts R Us Preferred Stock Classification Solution
[PDF]
HEARTS R US CASE SOLUTION

http://pdfebookcenter.com/file/hearts–r–us–case–solution.pdf
Status: Available
Read online and download Hearts R Us Case Solution. There are many Ebooks available in our
online library related with Hearts R Us Case Solution ......
[PDF]
STOCK SOLUTION TO WORKING SOLUTION
http://pdfebookcenter.com/file/stock–solution–to–working–solution.pdf
Status: Available
Read online and download Stock Solution To Working Solution. There are many Ebooks available
in our online library related with Stock Solution To Working Solution ......
[PDF]
STOCK SOLUTION EXAMPLE
http://pdfebookcenter.com/file/stock–solution–example.pdf
Status: Available
Read online and download Stock Solution Example. There are many Ebooks available in our online
library related with Stock Solution Example ......
[PDF]
STOCK

Tetracycline and Chloramphenicol Against Serratia Marcescens
Tetracycline and Chloramphenicol against Serratia marcescens
By
C. A. Bechdel
Abstract
The problem investigated was Serratia marcescens. We hypothesized that both Tetracycline and
chloramphenicol will be effective against treating S. marcescens. The experiment was conducted
with a single control group and two experimental groups. The experiment was replicated 8 times.
The experiment showed that in testing the control group S. marcescens, chloramphenicol had a
mean death zone of 30.9 mm +/– 2.80 mm, and tetracycline had a mean death zone of 20.8 mm +/–
2.91 mm. Chloramphenicol had a significantly greater mean death zone then that of tetracycline.
Introduction
The problem that was investigated in our experiment was to see which ... Show more content on
Helpwriting.net ...
Still holding the vial at a 45 degree angle, the swab was inserted into the vial to soak up the S.
marcescens for 10 seconds. Partly lifting the lid of one petri dish, shielding it over top like an
umbrella, we inoculated S. marcescens onto the agar growth medium in the petri dish. We repeated
these steps 2 more times to inoculate all 3 petri dishes. Once all three plates were inoculated with
the S. marcescens we removed our forceps from the alcohol. We air dried them, and then passed
them through the flam to sterilize them. Using the sterile forceps we placed the c disc in the center
of a petri dish and press down lightly to ensure that it stayed. It is then labeled it C, for the control
group, 5 for the replicate number, along with the date and time of the class. Again we sterilize the
forceps and place the T disc into the next petri plate. It is labeled the same way but with a T for
tetracycline. The T disc contained 30ug of the antibiotic. We repeat the sterilizing of the forceps one
more time and place the Chl disc on the remaining petri plate and labeled it Chl for
chloramphenicol. The Chl disc contained 30ug of the antibiotic. Once all 3 petri dishes are labeled
they were placed upside down to prevent water droplets from falling onto the nutrient agar substrate.
The last step to the experiment was to clean up. We placed our swabs in a waste beaker, cleaned up
our work stations, and then washed our hands with soap and

Oxidase Test Lab Report
Results
Gram Stain: The Gram Stain test was ran. The unknown bacteria F#1729 was stained and the result
was Gram Negative (–). This result identifies the layer of peptidoglycan being thin. This thin outer
membrane is composed of lipopolysaccharides that are not able to retain the crystal violet iodine
used, instead they slough off when rinsed with the ethanol alcohol. This leaves the color unretained
and the counterstain safranin is absorbed, staining the bacteria pink. Once the slide was ready, we
were able to observe the bacterial morphology under the microscope. We identified the bacterial
shape as bacillus under 100X magnification with oil immersion the morphology was verified.
Figure 1: (Pseudomonas Aeruginosa mixture, Under 100X oil immersion)
Oxidase Test: The oxidase results was positive as the color turned purple on the commercial rapid
dry card. This means that there was a presence of cytochrome oxidase enzyme which reduces
oxygen at the end of the transport chain of electrons. This test helped the identification of P.
Aeruginosa along with the other tests. Figure 2: Final result of Oxidase test.
Catalase Test: After doing the catalase test, as we put drops of 3% Hydrogen Peroxide, it starting
bubbling on the microscope slide which indicates a positive result. This means that the unknown
bacteria has the catalase enzyme present, which decomposes hydrogen peroxide into water and
oxygen. (Needs Editing)
Figure 3: Final result of Catalase test.

Antibacterial Soap Discs
The objective of this lab was to measure the zones of inhibition of the discs that were soaked in
different hand–cleansing agents/antibiotics and put in agar plates that were swabbed with
Escherichia coli culture. In order to do this, we used the Kirby–Bauer method. The Kirby–Bauer
method is a test of detect the antibiotic sensitivity to bacteria. The method is used by using
antibacterial discs to see which bacteria are affected by those antibiotics. My hypothesis, stated
before the experiment, was that penicillin will have the smallest zone of inhibition because it is an
antibiotic, and it will work the best.
Materials & Methods: The first task we had to perform in this lab was diluting an Escherichia coli
culture and compare it to the ... Show more content on Helpwriting.net ...
The smallest inhibition zone was in plate four which was the Penicillin Disc, it had a diameter of 10
mm. The agent with the highest MIC was in the plate four, the Penicillin Disc, and the agent with
the lowest MIC was inplate five, the Chloramphenicol Disc. The higher the diameter, the lower the
MIC and the lower the diameter, the higher the MIC. There were a number of things we did not take
in control of. We did not control for how long each group passed their forceps through the flame. If
everyone diluted their E. coli mixture with enough saline. And, for how long the antimicrobial discs
were soaking in the cleansing agents, some groups went first and put in the disks right after they
were put into the cleansing agents, and some groups went last after the discs absorbed most of the
cleansing

What Is A Transposon?
Transposition Mutagenesis: Post–lab Questions
Rebecca Herbert
Friday Lab Section
1a. What is a transposon?
A transposon is a section of DNA whose location can be moved, or transposed, from a plasmid to a
chromosome, or vice versa. Transposons are necessary if recipient DNA are missing a sequence that
complements the donor DNA. Also referred to as "jumping genes," transposons are unlike typical
DNA which usually does not move around, and are flanked by inverted repeat sequences which
contribute to their ability to move around.
1b. What is the transposon in this experiment?
The transposon in this experiment is contains kanR in between the inverted repeats on either end,
which will be transposed from the plasmid pVJT128 to the chromosome of the recipient bacteria.
2a. In the first part of the experiment, why did we put the donor on a plate containing nalidixic acid?
In the first part of the experiment, we plated donor bacteria, which was chloramphenicol resistant,
on a Nal plate. Because no donor bacteria would grow on a Nal plate, this was a way of ensuring
that the sample of donor E. Coli bacteria was pure.
2b. Why did we put the recipient on a plate containing chloramphenicol?
Similarly, the recipient E. Coli bacteria is resistant to nalidixic acid, and would be able to grow on a
Nal plate, but not on the Cm plate. By plating the recipient bacteria on chloramphenicol, we can
ensure that the sample was purely recipient if there is no growth.
3. How will we recognize a

The Effects of Antibiotics on Bacterial Growth
The Effects of Antibiotics on Bacterial Growth
Biology II 1996
Bacteria are the most common and ancient microorganisms on earth. Most bacteria are microscopic,
measuring 1 micron in length. However, colonies of bacteria grown in a laboratory petri dish can be
seen with the unaided eye.
There are many divisions and classifications of bacteria that assist in identifying them. The first two
types of bacteria are archaebacteria and eubacteria. Both groups have common ancestors dating to
more than 3 billion years ago. Archaebacteria live in environments where, because of the high
temperature, no other life can grow. These environments include hot springs and areas of volcanic
activity. They contain lipids but lack certain chemicals ... Show more content on Helpwriting.net ...
This antibiotic acts by limiting normal protein synthesis.
Streptomycin is effective against E. Coli, gram–negative bacilli, as well as many cocci.
Neomycin an antibiotic derived from a strain of Streptomyces fradiae.
Neomycin effectively destroys a wide range of bacteria.
Kanamycin an antibiotic substance derived from Streptomyces kanamycetius. Its antibacterial action
is very similar to that of neomycin. Kanamycin works against many aerobic gram–positive and
gram–negative bacteria, especially E. coli. Protracted use may result in auditory as well as other
damages.
Erythromycin is an antibiotic produced by a strain of Streptomyces erythreaus. This antibiotic works
by inhibiting protein synthesis but not nucleic synthesis. Erythromycin has inhibitory effects on
gram–negative cocci as well as some gram–positive bacteria.
Chloramphenicol is a clinically useful antibiotic in combating serious infections caused by certain
bacteria in place of potentially hazardous means of solving the problem. In lab tests, it has been
shown that this medicine stopped bacterial reproduction in a wide range of both gram–positive and
gram–negative bacteria. The inhibition of cell reproduction caused by Chloramphenicol takes place
through interference with protein synthesis.

An experiment was conducted in order to determine which antibiotics are most effective in
inhibiting bacterial growth. First, the different bacteria were placed on agar

Antimicrobial Susceptibility, Mic and Mbc
–––––––––––––––––––––––––––––––––––––––––––––––––
Antimicrobial Susceptibility, MIC and MBC
–––––––––––––––––––––––––––––––––––––––––––––––––
Microbiology Lab Report 3
Carolina Toscanojara
Antibiotic Sensitivity.
Objective:
Antibiotics are chemical compounds that selectively interfere with the growth of microorganisms
while causing little or no damage to the animal or human host. The purpose of this lab was to
determine the effectiveness antibiotics against any given bacterium by means of examining the zone
of inhibition, the minimum inhibitory concentration, and the minimum bactericidal concentration.
Introduction: Chemical antimicrobial agents are chemical compounds that are capable of either
preventing the microorganisms for ... Show more content on Helpwriting.net ...
It is necessary to target treatment more specifically against the offending bacterium in order to
reduce the risk of resistance emerging in other bacterial groups. Some antibiotics are narrow
spectrum, more effective against Gram–positive or Gram–negative bacteria, and little activity
against the other.
Methods:
Before testing was done both bacteria, Gram positive and Gram Negative had been inoculated in
3ml TSB for 24 hours at 37°C. After incubation and with the help of cotton swab 2 plates of
Mueller–Hinton agar were heavily inoculated with Gram positive obtained from the skin and Gram–
negative bacteria obtained from water respectively. Swapping was done by following the procedure
stated in the lab manual, going back and forth across one half of the plate ensuring the entire area
was covered, turning the plate 90o and swabbing from top to bottom and turning the plate one last
time a further 90o and repeat the swabbing in the indicated manner. Eventually 12 paper disks
containing enough of the antibiotic were placed on the possible cultures and left in the incubator for
24 hours at 37°C. After inoculation the diameters of the clear zones (zones of inhibition) around
each McFarland disk were measured with a standard ruler to the nearest millimeter. The
measurements obtained were matched against a chart to determine whether the bacterium was
resistant, sensitive, or intermediate in susceptibility to the antibiotic used.

Effectiveness Of Bacitracin, Gentamicin And...
Effectiveness of bacitracin, gentamicin and chloramphenicol on the growth of Escherichia coli
Introduction:
Escherichia coli (E. coli) is a bacterium commonly found in the digestive system of humans and
animals. Although it is mainly harmless and helps promote a healthy digestive system, some strains
can be pathogenic and cause illness such as diarrhea, urinary tract infections, respiratory infections
and even pneumonia. What makes E. coli pathogenic is the release of a toxin called Shiga. These are
often referred to a Shiga toxin–producing E. coli (STEC). This particular strain lives harmlessly in
the guts of animals, particularly cattle. However, when in contact with a human, it results in illness.
Pathogenic E. coli is usually caught when humans ingest invisible amounts of feces that can be
found in food or water. (CDC, 2014) Antibiotics may be prescribed depending on the illness. Their
ability to effectively work depends on it's composition and the bacteria it is expected to work on.
In a study by Jun Lin et al., it was stated that bacitracin is an antibiotic that has a growth–promoting
ability. This means that it would have no affect on inhibiting, or stopping the growth of bacteria, in
particular, E. coli. On the other hand, a study done by Sukayna M. Fadlallah et al. proved that
gentamicin proved a promising ground for treatment of E. Coli. Different molecular strains of E.
coli were subject to different regimens of antibiotics, including gentamicin. The results

Gram Test Lab Report Essay
Hypothesis: If the bacteria turns out pink/red then the gram test is negative.
Null Hypothesis: If the bacteria turns out pink/red then the gram test is not negative.
Purpose: Identify the three morphological types of bacteria and use the Gram's test to examine the
bacteria infection by the stain technique. Differ between plant and animal cells and the different
cellular components of eukaryotic cell. Describe the cell theory and explain its significance and the
difference between prokaryotic and eukaryotic.
Procedure:
1. Identify which cells are Gram–negative and Gram–positive.
2. Heat fix a culture of bacteria sample to prevent loss of bacteria during rinsing in the procedure
and identify the bacteria on the agar. Sterilize an inoculating loop and place a water droplet of tap
water on a clean slide.
3. Heat the loop again and let it cool and then open a culture tube and heat the neck of the bottle.
4. Lightly move the loop across the top of the agar to collect the bacteria. Flame the neck again and
replace the cap.
5. Use the loop to mix the bacteria with the ... Show more content on Helpwriting.net ...
The first we waited too long at the alcohol stage and it stripped away the bacteria. The second trial
however worked and we saw that the culture for Mary Farmer (Culture A) was pink rod–shaped
bacteria. However on the second trial for Culture B, we accidently blotted the petri dish too hard and
it took off the bacteria, making that trial invalid. After a few more trials, we finally managed to get
both bacterium correct. We also saw that the Culture B was round purplish–pink color and was
round looking bacteria. For the antibiotic test, we found the results of seven antibiotics and their
effectiveness against these two bacterium. The following graph will show the diameter for the zone
of inhibition for the bacteria and antibiotics. We found the antibiotics Chloramphenicol and
Tetracycline were the most effect against the two

S. Typhimulantation
The bacteria used in this question involved a chloramphenicol resistant S. typhimurium as the donor
cell, and a chloramphenicol sensitive S. typhimurium as the donor cell as well as P22 phage. Using
an overnight culture of resistant S. typhimurium, a P22 lysate was prepared. During the course of
the experiment, two titers of the sensitive S. typhimurium were prepared using dilutions of 10–6,
10–7, 10–8, and 10–9 for the 1st day, and 10–7, 10–8, and 10–9 on LB plates for the final titration to
find the CFU/mL for calculations. A titer for the P22 phage was also prepared (with S. typhimurium)
using dilutions 10–7, 10–8, and 10–9 on LB plates. This information was used to determine the
amount of phage needed for the transduction process, which ... Show more content on
Helpwriting.net ...
typhimurium was ran on the first day to determine the CFU/mL of the overnight culture in order to
calculate the volume of phage needed for transduction, the dilution of 10–8 was used since 93
colonies (9.3 x 109 CFU/mL) grew on the LB plate (See table 1). A titration of P22 phage and S.
typhimurium were also performed to determine the PFU/mL of the P22 phage, a control plate with
phage alone showed now growth, and the dilution 10–7 was found to have 132 plaques (1.32 x 109
PFU/mL). This value was used together with the dilution results of S. typhimurium on day 1 for
calculating the volume of phage (see sample calculation). An MOI of 0.01 was used with these two
values (volume of bacteria was .1mL) in order to determine the volume of phage needed for
transduction, which ended up being 7µl. Using this information, three plates were run for the
transduction, one plate with cells only on LB–CM, a plate with the cells and the phage on LB–CM,
and a plate with phage only on LB–CM. There was only growth on the cells and phage plate, giving
158 colonies (1.58x103/mL) (see figure 1. And table 1. for results). This indicated successful
transduction of the chloramphenicol gene since only colonies with the phage were able to grow on
the antibiotic plate. A "final" titration was simultaneously run for the specific sample of recipient S.
typhimurium actually used in the transduction, with the dilution of 10–8 resulting in 262 colonies
(2.62 x 1010

Antibiotic For Culture B Case Study
9. The most effective antibiotic for Culture A is Chlorapherical. The zone of inhibition had a
diameter of 31 millimeters. The larger the zone of inhibition the more effective the antibiotic is. The
antibiotic is preventing the bacteria from growing, essentially inhibiting the growth and creating the
circles. The clear circles around the antibiotic disks show the areas that the bacteria were not able to
grow. The smaller the circle or zone of inhibition the less effective the antibiotic is against the
culture of bacteria. The most effective antibiotic for Culture B is Tetracycline and Kanamycin. The
zone of inhibition was 23 millimeters for both antibiotics. They had the largest diameter, thus the
bacteria did not grow as much in comparison

Chloramphenicol And Protein Synthesis Lab Report
Introduction
In this practical, we will investigate and compare the mechanisms of action of the drugs:
Chloramphenicol and Rifampicin, specifically by identifying whether their effects are bacteriostatic
or bactericidal, and by looking at their effect on RNA and protein synthesis
Antibiotics can be divided into two categories: Bactericidal or Bacteriostatic. Bactericidal antibiotics
directly kill the micro–organisms, and depending on the amount given, the bacteria will not recover
after administration of the antibiotic is ceased. Bacteriostatic antibiotics prevent growth of the
bacteria, by targeting proteins that are involved in reproduction. Once the bacteriostatic antibiotic is
removed, population numbers usually increase again.
One of the drugs we will be investigating is Chloramphenicol. Chloramphenicol is a member of the
Amphenicol family/class of antibiotics. It is effective against gram–negative and gram–positive
bacteria. Members of the family work by targeting protein synthesis. Due to its ability to work
against gram–negative and ... Show more content on Helpwriting.net ...
Rifampicin specifically binds to and inhibits RNA polymerase in prokaryotic organisms. It is a
potent agent used to treat tuberculosis. It targets the majority of gram–positive bacteria and a
considerable number of gram–negative bacteria. It is able to kill intracellular microorganisms as it
can enter phagocytes. Drug resistance can arise quickly and easily, and is believed to occur due to a
chromosomal mutation, which results in a change in the DNA–dependent RNA polymerase.
Rifampicin is orally administrated, and has no common unwanted side effects. Side effects can
include: skin rashes, fever and gastrointestinal disturbances. Liver damage has been observed in rare
cases. Rifampicin also induces metabolising enzymes in the liver, and therefore drugs such as
warfarin may be quicker metabolised. (Dale and Rang,

Pneumoniae Lab Report
Experiment 1: Lactose–Fermenting Enterobacteriaceae (coliforms)
E. coli differs from K. pneumonia in terms of motility due to Brownian motion, exhibition of
oxidative and fermentative metabolism.
E. coli exhibited red colored media in indole test due to production of tryptophan while K.
pneumoniae showed negative result.
K.pneumonia used citrate as carbon source and produced alkaline products, changing the medium
colour to blue (Leland et al, 1940) but E.coli did not.
In kligler test, E.coli metabolized both lactose and glucose sugars and produced gas whereas K.
pneumonia could metabolize only lactose without gas formation. None of microorganisms produced
H2S. K.pneumoniae produced alkaline products (ammonia) from urea and changed the ... Show
more content on Helpwriting.net ...
This was followed by biochemical tests which are quicker ways to identify the sub classes of the
organisms. The results obtained are reliable. it is also an important step in the screening of infectious
agents in clinical specimens such as direct smears from a patient.
Isolation, gram staining and identification of the micro–organism is a basic diagnostic tool in
clinical as well as in research. This method is useful in diagnosis and treatment of diseases. The
gram staining is simple, least expensive and is rapid. It is useful in counting of total bacteria.
Because of the staining, the gram positive and negative bacteria can be viewed under the
microscope. The shape, size can be determined. The gram positive bacteria may lose the stain easily.
The retention of stain depends on the age of the cell. Old cultures get readily decolorized. Yet, this
method is feasible method for diagnosis of the minute

The Main Causes Of E. Coli Infects
In the present study, 45% of the urine specimens showed E. coli infections. Similar results were
reported by Salem et al. [12] in Egypt as E. coli was found in 58.75% of all urinary isolates from
hospitalized patients. Our results showed that E. coli was the most frequent microorganism isolated
from urine. The same result was reported by Salem et al. [12], Mohamed Al–Agamy et al. [15],
Evans et al. [16] and Kang et al. [17]. In our results, E. coli CIs (36.3%) were found the most in
ICUs, followed by the urosurgery ward (16.3%) and the general surgery ward (13.8%). Urine was
the major source (56.25%) of E. coli CIs, followed by sputum specimens (20%). This was in
agreement with the results of Salem et al. [12], who reported that E. coli is ... Show more content on
Helpwriting.net ...
The prevalence of the IntI1 gene was higher in the Pongpech et al. [20] study, in which the intI1
gene was detected in 99% of E. coli CIs and 87% of fecal specimen E. coli isolates. Other
comparable prevalences of the intI1 gene in gram–negative CIs have been reported in Western and
Central Europe, 43%, more than 50% in the Netherlands, 59% in France, and 75% among
aminoglycosides–resistant isolates from the USA [19].In the present study, there was a highly
significant difference between E. coli CIs and E. coli commensals in their susceptibility to different
antibiotics. All E. coli CIs and 70% of E. coli commensals were MDR strains. This was in
agreement with the study of Lee et al. [2], who reported that the rate of resistance to antimicrobial
agents was higher among nasocommial E. coli (98.5%) than those of E. coli commensals. A
difference in the resistance to antibiotics in our study was observed between the CIs and
commensals; about 100% of E. coli CIs were resistant to ampicillin, amikacin, tobramycin,
gentamycin, and trimethoprim/ sulfamethoxazole versus 50–55% of E. coli commensals. About 90–
95% of E. coli CIs versus 20–35% of E. coli commensals were resistant to piperacillin, amoxicillin/
clavulinate, streptomycin,

Effect Of Inhibition On Bacteria
Hypothesis
The antibiotics will have different zones of inhibition on different bacteria. Also, a range of
concentrations of the nutrients in the bacteria will change the bacterial growth.
Background information
Bacteria affected 2 million people from antibiotic resistance bacteria and 23,000 die per year due to
the infections. Bacteria works by entering the body in various ways, they can enter past nose, mouth
or ears as they are small, they can be inhaled from the air, eaten from food as well as through cuts/
open wounds.
Bacteria enters the body and asexually reproduces, they release toxins which cause infection.
Antibiotics either stop the bacterial cell from reproducing or kill the cell. They can disrupt the
bacteria by deterring ... Show more content on Helpwriting.net ...
Although some agar plates were hard to see if the streptomycin had a definitive zone of inhibition.
Ampicillin, erythro–mycin, penicillin, sulphafurazole was ineffective with no inhibition zone.
The trend I saw in the different concentrations of nutrients was the rod shaped bacteria which be–
come more obvious when more nutrients are added. At 0.1g, the agar plate looks mostly smooth but
at the 0.6g individual rod, shapes are prominent. Once it gets to 1.3g the colonisation is more
crowded, making it harder to see. This seems only visible effect of altering the nutrients is the rod
shaped forming and the visibility of them.
Graphs– appendix
Evaluation

Antimicrobial Chemotherapy : A Highly Respected Medical...
Introduction
Antimicrobial chemotherapy is a highly respected medical science which has shaped modern
humanity in many ways including the furthering the understanding of medicine. A wide variety of
antimicrobial substance have been discovered, designed and synthesized. Modern medicine is highly
dependent on chemotherapeutic agents that are used to treat diseases. Antimicrobials are combined
of chemotherapeutic agents and antibiotics. It can be defined as any substance of natural, synthetic,
or semisynthetic origin which at low concentrations kill or inhibits growth of microorganisms and
causes little or no damage. Antimicrobial Chemotherapy is a chemical compound that selectively
inhibits or kills bacteria without suggestively harming the ... Show more content on Helpwriting.net
...
Bacitracin inhibits cell wall synthesis by interfering with action of the lipid carrier that transports
wall precursors across the plasma membrane. Vancomycin Binds directly to the D–Ala–D–Ala
terminus and inhibits transpeptidation.
Certain drugs that are engaged in protein synthesis, differentiate between prokaryotic and eukaryotic
ribosomes. (Streptomycin, Gentamicin, Chloramphenicol, Tetracycline, Erythromycin, Clindamycin,
and Fusidic) Their therapeutic index is fairly high, but not as favorable as that of cell wall synthesis
inhibitors. Streptomycin Binds with the 30S subunit of the bacterial ribosome to inhibit protein
synthesis and causes misreading of mRNA. Chloramphenicol binds to the 50S ribosomal subunit
and blocks peptide bond formation through inhibition of peptidyl transferase. Tetracycline bind to
the 30S ribosomal subunit and interfere with aminoacyl–tRNA binding. Erythromycin and
Clindamycin bind to the 50S ribosomal subunit and inhibit peptide chain elongation. Fusidic acid
binds to EF–G and blocks translocation.
The antibacterial drugs that inhibit nucleic acid synthesis or damage cell membranes are not as
selectively toxic as other antibiotics. (Ciprofloxacin, Quinolones, and Rifampin) This is because
prokaryotes and eukaryotes do not vary in order to maintain the nucleic acid synthetic mechanisms
or cell membrane structure. Ciprofloxacin and Quinolones inhibit bacterial DNA Gyrase and
therefore interfering with DNA

Bacterial Strains : A Study And Their Sources
Engineering Section
Bacterial Strains:
Bacterial strains used in this study and their sources are listed in Table 1.
Table 1: Bacterial strains code, references and sources.
Source Strain code No. of strains Bacterial sp.
Microbial Genetics Dept., NRC BTN7B 1 Anoxybacillus flavithermus
Microbial Genetics Dept., NRC N3 1 Bacillus alvei
Elhamshary et al. (2008) Bc6 3 Bacillus cereus
Bacillus Genetic Stock Center 6A15
Soliman et al. (2003) I6
Microbial Genetics Dept., NRC 5A3 2 Bacillus licheniformis
Microbial Genetics Dept., NRC N5
Microbial Genetics Dept., NRC I1 1 Bacillus pumilus
Bacillus Genetic Stock Center 9A5 1 Geobacillus stearothermophilus
Microbial Genetics Dept., NRC BTN7a 4 Bacillus subtilis
Faculty of Science, Ain Shams B.S Ain Shams
Microbial Genetics Dept., NRC DB100
Faculty of Science, Al–Azhar Univ. B.S Alazhar
Dr. Priest, F.G., Heriot Univ., England BTI. A 3
Bacillus thuringiensis
Dr. Priest, F.G., Heriot Univ., England BTI. B
Microbial Genetics Dept., NRC BT.K
Microbiological Resources Center (Cairo MIRCEN) Migula 1895Al 1 Pseudomonas fluorescens
Plasmids: pJET/blunt, 2974bp, Ampr (Thermo scientific, USA), Fig. 1 pGEM–Teasy, 3016bp, Ampr
(Promega Co. Madison, USA), Fig. 2
Medium and growth conditions:
Lauria–Bartani (LB) medium Davis et al., (1980). It was used for bacterial growth. It consists of
(gm/l): Trypton; 10.0 gm, Yeast extract; 5.0 gm and NaCl; 5.0 gm. For solid medium, Agar Agar;
20.0 gm was added. Growth

The Effects Of Antibiotics On Two Different Species Of...
Aim: To design an experiment to investigate and observe the effects of selected antibiotics on two
different species of bacteria (M.luteus & E.coli).
Introduction:
Bacteria are single celled microbes with a simple cell structure. They do not contain a nucleus or
membrane, instead their control centre is contained in a single loop of DNA. Some types of bacteria
have the ability to become resistant to certain antibiotics. Bacteria can be found virtually anywhere
and everywhere. They are in the air, soil and water and all over plants and animals, including us.
"Each square centimetre of your skin averages about 100,000 bacteria, and there are over 500
different species in the human mouth" (Spectrum Science Communications, 2015). Bacteria are
classified

C Botulinum: A Case Study
Treatment for C. botulinum can include inducing vomiting, antitoxin, antibiotics, breathing
assistance machine and rehabilitation (Mayo Clinic Staff, 2015). The action of treatment is decided
on how the disease got into a patient's body. For foodborne C. botulinum, doctors want to clear out
the patient's digestive system by inducing vomiting and giving medication to speed up their bowel
movements (Mayo Clinic Staff, 2015). If a patient is diagnosed early with foodborne or wound C.
botulinum they can be injected with antitoxin (Mayo Clinic Staff, 2015). The antitoxin attaches
itself to the toxin that is in the blood and can keep it from harming their nerves (Mayo Clinic Staff,
2015). Before administration of antitoxin a skin test should be done ... Show more content on
Helpwriting.net ...
botulinum antibiotics are recommended for their treatment (Mayo Clinic Staff, 2015). However,
antibiotics should not be used on patients with other types of C. botulinum because it can advance
the release of the toxins (Mayo Clinic Staff, 2015). There are three different antibiotics that can be
used on wound C. botulinum patients, Penicillin G (Pfizerpen), Chloramphenicol (Chloromycetin),
and Clindamycin (Cleocin). Penicillin G is the preferred drug for wound C. botulinum the other two
are an alternative to penicillin (Chan–Tack, 2015). "Penicillin G interferes with synthesis of cell wall
mucopeptide during active multiplication, resulting in bactericidal activity against susceptible
microorganisms" (Chan–Tack, 2015). "Chloramphenicol binds to 50S bacterial–ribosomal subunits
and inhibits bacterial growth by inhibiting protein synthesis. Effective against gram–negative and
gram–positive bacteria" (Chan–Tack, 2015). "Clinadmycin inhibits bacterial growth, possibly by
blocking dissociation of peptidyl tRNA from ribosomes, causing RNA–dependent protein synthesis
to arrest" (Chan–Tack, 2015). The adverse effects of Penicillin G are seizures and anemia. The
adverse effects of Chloramphenicol have a less than one percent frequency, but include nightmares,
headache and a rash (Chan–Tack, 2015). The adverse effects of Clindamycin include abdominal
pain, diarrhea and fungal overgrowth (Chan–Tack,

The Effects Of Antibiotics Bacterial Growth?
Randhawa 1
Zorawar Randhawa
Mrs. Eideh
Honors Biology
8 June 2015 Effects of Antibiotics Bacterial Growth
Bacteria are the most common and ancient microorganisms on earth. Most bacteria are microscopic,
measuring 1 micron in length. However, colonies of bacteria grown in a laboratory petri dish can be
seen with the unaided eye. When considering the pH level, bacteria are classified as either
acidophiles (acid–loving), neutrophiles (neutral ph range), or alkaliphiles (alkali–loving). The one
that causes disease in humans would be the neutrophiles, which have an ideal pH range of 5.4 to 8.0.
There are exceptions, however, like Alcaligenes faecalis and Vibrio choleae, which are both
alkaliphiles and can infect humans. There are physical and nutritional factors that affect bacterial
growth in the environment. Sterilization is needed to keep an environment free from bacterial
growth. Failure to sterilize bacterial growth in our food products today leads to the unfortunate
consequence of food poisoning.
Randhawa 2 During lag phase, bacteria adapt themselves to growth conditions. It is the period
where the individual bacteria are maturing and not yet able to divide. During the lag phase of the
bacterial growth cycle, synthesis of RNA, enzymes and other molecules occurs.
The log phase (sometimes called the logarithmic phase or the exponential phase) is a period
characterized by cell doubling.[3] The number of new bacteria

Escherichia Albertii Research Paper
Escherichia albertii is an emerging gram–negative discretional rod that has been related to multiple
cases of human diarrheal disease, especially in young children. The purposes of this study were to
illustrate the antibiotic resistance traits and the growth of individual strains of E. albertii on raw
ground beef at different storage temperatures.
First, the bacteria stains were isolated. Next, using the Broth microdilution assay (a method used to
test the susceptibility of bacteria to antibiotics), antibiotic resistance was decided. Two samples were
germ free and diluted with peptone diluent and endured for 1 min. Survivors were itemized by
spread plating of antiseptic petri dishes with tryptic soy agar, followed by the oxygenation and
incubation of plates. With beef bought from the same market as before, evenly divided portions of it
was injected with E. albertii, separately. Following plating on day zero, samples stored at 5°C, 22°C,
and 35°C were all removed from incubation and processed for E. albertii listing, with respects to
their various time intervals. Beef samples were then removed, mixed with PW, and mixed together
by hand massaging for 1 min before preparation of serial dilutions and plating of survivors. E.
albertii was ... Show more content on Helpwriting.net ...
Surviving E. albertii and moderate temperature organisms and aerobes were listed following 24
hours of oxygenated incubation, whereas

Antibacterial Effects Of The Chloramphenicol Antibiotic On...
The Antibacterial Effects of the Chloramphenicol Antibiotic on Escherichia coli
Kenneth Tungol
12/10/2015
BIOL 1B
Abstract
Chloramphenicol is an antibiotic known to treat a broad range of bacteria. In this study, the
effectiveness of Chloramphenicol was tested on the DH5α strain of Escherichia coli. Knowing that
varying the concentrations of Chloramphenicol will result in different effects on the E. coli strain,
we conducted an experiment that agar–plated the E. coli with Chloramphenicol with concentrations
together. The concentrations ranged from no antibiotic to excess antibiotic in hopes to find the
minimum inhibitory concentration (MIC). The study yielded the MIC of Chloramphenicol to be
85μg/mL, determining the borderline between the effectiveness and the ineffectiveness of
Chloramphenicol against the DH5α strain.
Introduction
What is Chloramphenicol?
Chloramphenicol is an antibiotic that originated from Streptomyces venequelae in 1947 and is the
first antibiotic to be discovered as broad spectrum ("National Center," 2004). Broad–spectrum
antibiotics are able to treat various types of bacteria. Chloramphenicol treats serious bacterial
infections that are not treatable by other antibiotics ("Chloramphenicol Injection," n.d.). Since
Chloramphenicol is a broad spectrum antibiotic, it is effective against both gram positive and gram–
negative bacteria. It diffuses through the bacterial cell wall and reversibly binds to a receptor site on

The Growth Of Bacteria Known As Citrobacter Freundii As...
Table of Contents
Abstract 2
Scenario 2
Background Information 3
Citrobacter Freundii 3
Classification 3
Infections and diseases. 4
Anti–biotic rings 5
Streptomycin 5
Chloramphenicol 5
Penicillin g 5
Tetracycline 5
Ampicillin 6
Sulphatriad 6
Aim 7
Proposed Questions/ hypothesis 7
Apparatus 8
Assumptions and Effects 8
Procedure 9
Safety 10
Results 11
Discussion 13
Significant questions resolved. 13
Problems/ future recommendations 14
Scenario Evaluation 14
Conclusion 15
Reference List 16
Appendix 17
Abstract
The purpose of this report is to analyse the growth of the bacteria known as Citrobacter Freundii as
well as distinguishing what antibiotics effect its growth. This will be done so by answering the
following question after completing its associated experiments. This question includes: what
antibiotics are most effective in denaturing the bacteria? It has been predicted that chloramphenicol
will be the most effective due to the fact that its medical uses are treating meningitis which is an

infection caused by Citrobacter freundii. After conducting the experiments it was found that the
chloramphenicol antibiotic was the most effective in denaturing the bacteria, although streptomycin
was also affective. However, none of the other antibiotics were able to halt the growth of the
bacteria.
Scenario
A series of moderately severe infections at Rockhampton Base Hospital has alerted authorities to a
minor outbreak of Citrobacter Freundii, an opportunistic pathogen known to

Coke Machine Button
My bacterium was swabbed off of a coke machine button. I decided to swab this particular spot
because I believed there would be numerous bacteria found there since I see people everyday
punching a button to get a cool beverage during breaks in between classes every day. To my
surprise, there was only one colony that grew on the agar we had smeared it on. This was very
surprising to me because I was sure there would be more bacteria growing on the machine rather
than only one colony. The bacteria I was working with occupied a very small amount of space on the
agar. The tiny spot, in which I called my bacteria, appeared to be an off white or creamy color and
had much of a sticky looking texture to it, although I did not touch it. It was also very glossy and the
colony was in a circular shape but only took up as much space as a small tick would. After going
through all of the fun steps of gram staining, with the critical steps of inhibiting crystal violet,
Potassium Iodide, Alcohol, and Safranin, the bacteria on my slide turned out to be much of a faded
color of pink. Thereafter, I was then told that I had messed up terribly by pouring an excessive
amount of alcohol onto my slide and it was then realized it was meant to be a dark purple color.
With it being the ... Show more content on Helpwriting.net ...
In the Sugar Fermentation experiment I ended up with three negatives, being Mannitol, Sorbitol, and
Arabinose, and four positives, Lactose, Glucose, Sucrose, and Maltose. In the Litmus milk project,
my bacteria turned out to be top neutral with reduction in the bottom. I had no coagulation, no
peptonization, negative for Acid, and negative for Alkaline. A few other tests indicated I was
positive for Arginine and Lysine, but I had tested negative for Bile Esculin. The bacterium tested
was positive for all of the salts as well as for the TSI agar and the

Uknown Microorganism Lab Report
31 October 2011
Identification and observations of Citrobacter Freundii
Introduction
Citrobacter Freundii is a species of bacteria that can be potentially harmful to humans. It is known to
cause meningitis by protruding into the brain and replicating itself (1). The Citrobacter species has
also been found as a cause of some urinary tract infections, diarrhea, and even gastrointestinal
diseases and symptoms (3). C. Freundii can be located in a wide variety of soils and water (3).
Lastly, it is also the cause of many nosocomial infections due to its presence in water (1).
Identifying C. Freundii holds importance in order to determine infection in gastrointestinal and
urinary tracts and in the brain. These infections will often be ... Show more content on
Helpwriting.net ...
Table 3 shows Gram stain results that indicated C. Freundii as a gram negative bacterium in rod
shapes scattered in singles and some in pairs. Each gram stain produced the same results. The
Bartholomew and Mittwer method of endospore staining indicated that C. Freundii tested negative
for endospore formation. Table 4 shows the biochemical test results of the unknown and the official
test results for comparison. The Kirby–Bauer antibiotic tests indicated that the unknown is
susceptible to chloramphenicol and ampicillin and resistant to penicillin G and tetracycline. The
disinfectant sensitivity tests indicated that C. Freundii is resistant to all four of the disinfectants.
Discussion
The biochemical tests, the Gram stain, the Bartholomew and Mittwer's stain, the microscopic and
macroscopic observations, and chemical sensitivity tests helped to identify the unknown bacteria as
Citrobacter Freundii. Each biochemical test result maintained consistency with the

Polyymyxin B Research Paper
Antibiotics target specific structure or process of the cell. Such as, inhibition of cell wall synthesis,
Inhibition of protein synthesis, Injury to plasma membrane, & Inhibition of nucleic acid synthesis.
These drugs include, such as B lactam drugs that are bactericidal & kill bacteria by interfering with
the synthesis of the cell wall, Polymyxin B drugs that injures the plasma membrane allowing the cell
to burst. Tetracycline & Chloramphenicol that are bacteriostatic drugs, and inhibits protein
synthesis. Fluoroquinolones & Rifamycin that are bactericidal drugs & interfere with the synthesis
of nucleic acid. The pathogens can develop resistance against these drugs that are used to treat them.
Resistance to antibiotics can be acquired by mutation

Rloia Pickettiir
Results and Discussion:
The wild type RpNiR and pEC86 plasmids were purified by the miniprep DNA purification system
and quantified by nanodrop spectrophotometer. The concentrations of RpNiR were found to be
145.4 ng/µl and 145.1 ng/µl. While pEC86 concentrations were 167.7 ng/µl and 128.9 ng/µl.
In the PCR experiment with RpNiR–pET26b templet, the PCR product was transformed into
competent cells but there were no colonies observed. Therefore, the product was checked by running
agarose gel. The samples were viewed under the UV light and the results only showed DNA ladder
bands with no observation of the plasmid band. That might be due to lack of pipetting accuracy as
small quantities of solutions needs to be accurately transformed. Or that ... Show more content on
Helpwriting.net ...
A future experiment for site directed mutagenesis/PCR might involve a slightly increased amount of
template DNA and primers in the PCR reaction or increased amount of PCR product that is being
transformed, in case if the transformation of the plasmid did not work. Another possible change
could be done to the PCR thermal cycles, by altering the denaturation and annealing temperatures to
a reasonable degree. This is to ensure amplification of the desired plasmid DNA incorporating the
desired mutation with accuracy at the appropriate locations within the DNA template. A future
experiment for protein expression and purification should be done with further precision. And more
care needs to be taken as to include all necessary antibiotics during transformation and expression,
depending on the type of plasmids used in the experiment. This is essential to obtain the desired
protein containing the appropriate genes to procced with further

Antibiotics Effects On Growth Rate Of Bacteria Escherichia...
Antibiotics Effect on Growth Rate
Antibiotics are important for the treatment of bacterial infections, and it is therefore important to
know how different antibiotic works in different contexts. Different kinds of bacteria are affected to
different degrees by different antibiotics, and it may therefore be useful to know which antibiotic
that attacks the bacteria. The purpose of this report is to analyze how antibiotics including
Chloramphenicol and Ampicillin affect the growth rate of bacteria Escherichia coli and Bacillus
subtilis. Which antibiotic is the most effective or least effective in inhibiting the growth rate of these
two bacteria respectively?
In the article Growth Chart (www.vetbact.org, 2015–11–19) it was written that bacteria are
unicellular organisms that are in good nutrient availability can multiply indefinitely by dividing. It
takes different amounts of time for different bacteria that doubled – this time called the generation
time. When adding bacteria to a culture medium, it takes only a moment before they have adapted to
their new environment.
MicrobeWiki writes in his report Bacillus subtitles (microbewiki.kenyon.edu, 2016–05–10) that B.
subtitles are gram–positive bacteria, facultative anaerobic bacteria which are classified as non–
pathogenic. It occurs all over the place, for example in air, compost and soil, but can also be on the
skin and in the human intestine, although it is not as common. Escherichia coli are gram negative,
facultative

Chloramphenicol Cause Damage To The Human Body
Chloramphenicol: CllHIZClzNzOs
Chloramphenicol is a broad spectrum antibiotic, meaning it can actively work against both gram–
positive and gram–negative bacteria. In both cases the target of any antibiotic is the breakage of the
peptidoglycan cross–linkages, which results in the loss of rigidity of the cell and its consequent
death. It is mostly bacteriostatic in effect but can be bactericidal in higher concentrations.
What is it used for?
Use in Humans
Chloramphenicol can easily cause damage to the human body, such as irreversible aplastic anemia
and reversible bone marrow toxicity. [1] For this reason, the use of this drug is limited to the more
serious forms of bacterial invasion in humans. Examples include diseases that are deliberately ...
Show more content on Helpwriting.net ...
http://www.ncbi.nlm.nih.gov/books/NBK21574/
Inhibition of protein synthesis, Chloramphenicol irreversibly binds to a receptor site on the 50S
subunit of the bacterial ribosome, inhibiting peptidyl transferase. This inhibition consequently
results to the prevention of amino acid transfer to growing peptide chains, ultimately leading to
inhibition of protein formation. http://amrls.cvm.msu.edu/pharmacology/antimicrobials/antibiotics–
of–veterinary–importance/chloramphenicol How is it administered?
The two methods this drug can be administered or orally or parenterally. The latter would mean
injection or infusion, but is avoided unless the patient suffers major infection.

Reaction Paper On Salmonella Typhi
Abstract The Salmonella typhi shows the resistance against several antibiotics in different regions of
the world. The pattern of resistance is also variable worldwide. The antibiotic resistant character of
the S. typhi is due to the production of several enzymes against antibiotics and mutations in genes.
DNA gyrase A, active efflux, and plasmid mediated resistance patterns are involved in the resistance
against antibiotics like ampicillin, quinolones, chloramphenicol, tetracyclins, co–trimoxazole,
ciprofloxacin and in few strains cefitriaxone. Several lactamases, reductases and acyltransferases are
major contributor of the resistance patterns.
Introduction
Salmonella enterica subspecies enterica serotype typhi is genetically the monomorphic, restrict
human pathogenic bacteria (Gevers D. et al., 2005). Typhi enters in few individuals as the carrier
and shed high level of bacteria without any symptoms. It is believed that typhi was first evolved in
Indonesia that have flagellar antigen (Mortimer et al., 1999; Frankel et al., 1989). The fever caused
by Salmonella enterica is a major health problem and resulted by the poor hygiene conditions. The
enteric infection is worldwide and occurs in both developing and developed countries. It is ... Show
more content on Helpwriting.net ...
typhi. The transfer of ACCoT–resistance of S. typhi isolates has been reported earlier from different
parts of India. It has been reported that about 120 kb plasmid encodes resistance to A, C, T, and
streptomycin in S. typhi isolates from Kolkata (1989–1990). This result, the investigation of R–
plasmid contained in strains of S. typhi. AGE (Agarose Gel Electrophoresis) analysis elaborated the
presence of a single plasmid that is of approximately 55 kb among the isolates. Thus present
findings suggest that MDR S. typhi may arise from sensitive isolates by acquisition of multidrug
resistance plasmid from antibiotic–resistant enteric

Meningitis Research Paper
Meningitis – is a kind of infection or inflammation that affects the delicate membranes of the brain
and spinal cord in infected individuals.
Bacterial meningitis is fatal and contagious among people in close contact and can be caused by
several bacteria. The most common cause in children and adults are Neisseria meningitidis
(meningococcus), Streptococcuspneumoniae (pneumococcus) and among elderlies are Listeria
monocytogenes. These forms of infections need immediate medical attention. (1)
Figure 1: This photograph shows the graph of having meningitis on our membranes.
Viral meningitis and fungal meningitis are less severe otherwise and most people recovered
completely ... Show more content on Helpwriting.net ...
It was first discovered in 1805 by Vieusseux during an outbreak in Switzerland and later identified
by Anton Weichselbaum in 1887. It was given the name Neisseria intracellularis due to its
intracellular oval micrococci (3) and was placed in the Nisseria genus for its characteristics and
close relation to Neisseria gonorrhoeae. It was then later named Neisseria meningitidis by
bacteriologist Albert Ludwig Sigesmund Neisser.(4)
In 1992–1993 endemics were reported in United States and Canada, in Spain in 1995–1997 on
average of 3,000 new cases of meningitis are reported each year with only about 10–12% are fatal
and of which 30% are survivors with long–term consequences.(5) In West Africa known as the
"Meningitis Belt", 100 to 800 people in 100,000 are infected and this number can reach as high as
1,000 per 100,000. The largest outbreak reported was in Africa in 1996 with 250,000 cases recorded
and of which 25,000 deaths occurred.(6)
Meningococcal meningitis most commonly occurs in children and teens and leading cause of
bacterial meningitis in adults. The infection occurs more often in winter or spring.

Lab Report: Antibiotic Evaluation by the Kirby-Bauer Method
Lab Report: Antibiotic Evaluation by the Kirby–Bauer Method
Introduction
Chemical antimicrobial agents are chemical compounds capable of either inhibiting the growth of
microorganisms or killing them outright. Those which are taken internally to alleviate the symptoms
of or promote healing from disease are called chemotherapeutic drugs, and among these is a class of
compounds called antibiotics. In order for a chemotherapeutic drug to be classed as an antibiotic, it
must be produced by a microorganism such as bacterium or fungus or at least derived from a
chemical produced by one. It must also be capable of killing or inhibiting the growth of other
microorganisms and of doing so when taken in very small quantities. To study ... Show more content
on Helpwriting.net ...
(DrugBank)
Polymyxin B, a mixture of polypeptides derived from Bacillus polymyxa. It can be used
bactericidally against most Gram negative bacteria and is applied most often against urinary tract,
blood, and meningal infections of Pseudomonas aeruginosa. It has no effect upon Gram positive
bacteria. It kills bacterial cells by binding to a removing lipids in the cell membrane. Due to this
mechanism, however, Polymyxin B also damages eukaryotic cells and thus sometimes proves to be
a neuro– and nephrotoxic in humans. (DrugBank)
Tetracycline, synthesized from chlortetracycline, a compound produced by a Streptomyces. It works
by binding to the bacterial ribosome and interfering with protein synthesis and is effective against a
wide range of Gram positive and negative bacteria, including the Mycoplasma and the bacteria
responsible for Rocky Mountain Spotted Fever and nongonococcal urinary tract infections.
(DrugBank)
Material and Methods
Cultures: Streptococcus faecalis Staphylococcus aureus Escherichia coli
1 Pseudomonas aeruginosa
One person each in a team of four heavily inoculated two Mueller–Hinton agar plates with one of
the cultures listed by aseptic transfer from a broth culture using a sterile cotton swab. Each plate was
marked off into four segments, a total of eight sectors. One McFarland standard disk containing one
of the eight antibiotics tested was placed, using

Chloramphenicol

Recommended

Recommended

More Related Content

More from Alexis Naranjo

More from Alexis Naranjo (20)

Recently uploaded

Recently uploaded (20)

Chloramphenicol