Antimicrobial Susceptibility, Mic And Mbc

Antimicrobial Susceptibility, Mic and Mbc
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Antimicrobial Susceptibility, MIC and MBC
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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
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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 37В°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 37В°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.

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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,

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

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

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

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

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

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,

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

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,

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,

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.
SourceStrain codeNo. of strainsBacterial sp.
Microbial Genetics Dept., NRCBTN7B1Anoxybacillus flavithermus
Microbial Genetics Dept., NRCN31Bacillus alvei
Elhamshary et al. (2008)Bc63Bacillus cereus
Bacillus Genetic Stock Center6A15
Soliman et al. (2003)I6
Microbial Genetics Dept., NRC5A32Bacillus licheniformis
Microbial Genetics Dept., NRCN5
Microbial Genetics Dept., NRCI11Bacillus pumilus
Bacillus Genetic Stock Center9A51Geobacillus stearothermophilus
Microbial Genetics Dept., NRCBTN7a4Bacillus subtilis
Faculty of Science, Ain ShamsB.S Ain Shams
Microbial Genetics Dept., NRCDB100
Faculty of Science, Al–Azhar Univ.B.S Alazhar
Dr. Priest, F.G., Heriot Univ., EnglandBTI. A3
Bacillus thuringiensis
Dr. Priest, F.G., Heriot Univ., EnglandBTI. B
Microbial Genetics Dept., NRCBT.K
Microbiological Resources Center (Cairo MIRCEN)Migula 1895Al1Pseudomonas 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

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 5В°C,
22В°C, and 35В°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

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

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
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

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 DH5О±
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 85Ојg/mL,
determining the borderline between the effectiveness and the ineffectiveness of Chloramphenicol against the DH5О± 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

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.

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 гЂ–10гЂ—^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

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

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

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

Essay on Hearts R Us Preferred Stock Classification Solution
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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

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

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/Вµl and 145.1 ng/Вµl. While pEC86 concentrations were 167.7 ng/Вµl and 128.9 ng/Вµl.
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

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

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 AggRStxIPaHeaeTotal ++++
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.
AntibioticsSensitiveResistanceIntermediateTotal
Chloramphenicol31
(67.4%)8
(17.4%)7
(15.2%)46
(100%)
Ceftriaxone29
(63.0%)4
(8.7%)13
(28.3%)46
(100%)
Ciprofloxacin24
(52.2%)11
(23.9%)11
(23.9%)46
(100%)
Gentamicin19
(41.3%)11
(23.9%)16
(34.8%)46
(100%)
Tetracycline1
(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 rhoAggRStxIPaHeae
Ciprofloxacin0.1050.317*–0.1400.105 0.4860.0320.3520.486
Chloramphenicol0.0320.238–0.253. 0.8320.1110.090.
Ceftriaxone0.1150.2620.377**. 0.4470.0780.010.
Gentamicin0.2170.219–0.171. 0.1480.1430.257.
Tetracycline0.2250.427**–0.125. 0.1320.0030.408. *Correlation is significant at P. value в‰¤ 0.05 **Correlation is significant at P. value в‰¤ 0.01
4–7

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
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

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

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

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 7Вµl. 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

The Growth Of Bacteria Known As Citrobacter Freundii As...
Table of Contents
Abstract2
Scenario2
Background Information3
Citrobacter Freundii3
Classification3
Infections and diseases.4
Anti–biotic rings5
Streptomycin5
Chloramphenicol5
Penicillin g5
Tetracycline5
Ampicillin6
Sulphatriad6
Aim7
Proposed Questions/ hypothesis7
Apparatus8
Assumptions and Effects8
Procedure9
Safety10
Results11
Discussion13
Significant questions resolved.13
Problems/ future recommendations14
Scenario Evaluation14
Conclusion15
Reference List16

Appendix17
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

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
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.

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

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 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.
SourceAggRStxIPaHeaetotal ++++
Khartoum6
(13.0%)3
(6.5%)9
(19.6%)0
(0.00%)
18
(39.1%)
Omdurman5
(10.9%)0
(0.00%)7
(15.2%)0

(0.00%)
12
(26.0%)
Bahri3
(6.5%)2
(4.3%)3
(6.5%)0
(0.00%)
8
(17.3%)
Total14
(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.
AntibioticsSensitiveResistanceIntermediateTotal
Chloramphenicol31
(67.4%)8
(17.4%)7
(15.2%)46
(100%)
Ceftriaxone29
(63.0%)4
(8.7%)13
(28.3%)46
(100%)
Ciprofloxacin24
(52.2%)11
(23.9%)11

(23.9%)46

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

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.

Antimicrobial Susceptibility, Mic And Mbc

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