This document discusses bacteriology of water. It begins by introducing that drinking water should be visually acceptable, clear, and free of pathogens and chemical toxins. Many diseases are waterborne, spread through fecal contamination of water sources. The document then discusses the different types of bacteria found in water based on the source of contamination - natural water bacteria, soil bacteria washed in from rains, and sewage bacteria from fecal contamination. It also discusses factors affecting bacterial levels in water and various indicator organisms used to test for fecal contamination. Methods for collecting, transporting, and testing water samples are also summarized.
This is prepared for my project and im sharing this for useful to others.This slides contain the processing of urine specimens in microbiology.im prepared on basis of our medical college method.sometimes the methods will vary with other hospitals
This is prepared for my project and im sharing this for useful to others.This slides contain the processing of urine specimens in microbiology.im prepared on basis of our medical college method.sometimes the methods will vary with other hospitals
Microbiology of E coli giving basic of Escherichia coli, its morphology, cultural and biochemical characteristics, Antigenic character, pathogenesis, laboratory diagnosis, prevention and control
Automated system for bacterial identificationDEEKSHANT KUMAR
[DOWNLOAD IT OPEN IT WITH MICROSOFT POWERPOINT THEN YOU WILL BE ABLE TO UNDERSTAND THE TOPIC COVERED.]
1. WHOLE TEXT IS RELIABLE.
2. TEXT HAS BEEN TAKEN FROM STANDARD TEXT BOOK FOR MEDICAL MICROBIOLOGY.
3. SOME PICTURE HAS BEEN TAKEN FROM JOURNAL.
Microbiology of E coli giving basic of Escherichia coli, its morphology, cultural and biochemical characteristics, Antigenic character, pathogenesis, laboratory diagnosis, prevention and control
Automated system for bacterial identificationDEEKSHANT KUMAR
[DOWNLOAD IT OPEN IT WITH MICROSOFT POWERPOINT THEN YOU WILL BE ABLE TO UNDERSTAND THE TOPIC COVERED.]
1. WHOLE TEXT IS RELIABLE.
2. TEXT HAS BEEN TAKEN FROM STANDARD TEXT BOOK FOR MEDICAL MICROBIOLOGY.
3. SOME PICTURE HAS BEEN TAKEN FROM JOURNAL.
This presentation is made for S.Y.Bsc. Students.
The presentation includes Drinking water microbiology. The presentation includes information about coliform, indicator organisms as well as purification methods of drinking water.
Detection Of Escherichia Coli, An Indicator Of Feacal Contamination, In Drink...IOSR Journals
The detection of Escherichia coli as an indicator of faucal contamination in drinking water sources in Amassoma town, a host Community of the Niger Delta University, Bayelsa State in the Niger Delta of Nigeria, was carried out to determine their suitability for drinking. Result obtained showed mean total coliform bacterial counts of 2.05 x103 cfu/ml for borehole water, 1.25x103 cfu/ml for well water and 1.0x103 for pipe borne water. The mean count of faecal coliform was 2.1x103 cfu/ml for borehole water, 4.5x10 cfu/ml for well water and 1.0x10 cfu/ml for pipe borne water. The faecal coliform identified was Escherichia coli. Sources of contamination were found to be septic tanks, waste dump sites and periodic flooding of the area, being a typical wetland environment. It was concluded that water from the different sources studied in Amassoma did not meet the world health Organization (WHO) standard for drinking water. This study has therefore shown the need for continuous monitoring of our water supply systems.
The objective of the study was determining the pot ability of water from some part of Visnupuri area Nanded. The total coliform count in drinking water samples was in the ranges of 140-920 MPN index/100 ml. The data suggested that the quality of drinking water deterioration in rural habitations of this region was due to poor sanitation & contaminated water supply. The occurrence of some pathogenic bacteria in drinking water may increase the risk of water related diseases & health
problem in local residents.
Report Back from SGO 2024: What’s the Latest in Cervical Cancer?bkling
Are you curious about what’s new in cervical cancer research or unsure what the findings mean? Join Dr. Emily Ko, a gynecologic oncologist at Penn Medicine, to learn about the latest updates from the Society of Gynecologic Oncology (SGO) 2024 Annual Meeting on Women’s Cancer. Dr. Ko will discuss what the research presented at the conference means for you and answer your questions about the new developments.
Title: Sense of Taste
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the structure and function of taste buds.
Describe the relationship between the taste threshold and taste index of common substances.
Explain the chemical basis and signal transduction of taste perception for each type of primary taste sensation.
Recognize different abnormalities of taste perception and their causes.
Key Topics:
Significance of Taste Sensation:
Differentiation between pleasant and harmful food
Influence on behavior
Selection of food based on metabolic needs
Receptors of Taste:
Taste buds on the tongue
Influence of sense of smell, texture of food, and pain stimulation (e.g., by pepper)
Primary and Secondary Taste Sensations:
Primary taste sensations: Sweet, Sour, Salty, Bitter, Umami
Chemical basis and signal transduction mechanisms for each taste
Taste Threshold and Index:
Taste threshold values for Sweet (sucrose), Salty (NaCl), Sour (HCl), and Bitter (Quinine)
Taste index relationship: Inversely proportional to taste threshold
Taste Blindness:
Inability to taste certain substances, particularly thiourea compounds
Example: Phenylthiocarbamide
Structure and Function of Taste Buds:
Composition: Epithelial cells, Sustentacular/Supporting cells, Taste cells, Basal cells
Features: Taste pores, Taste hairs/microvilli, and Taste nerve fibers
Location of Taste Buds:
Found in papillae of the tongue (Fungiform, Circumvallate, Foliate)
Also present on the palate, tonsillar pillars, epiglottis, and proximal esophagus
Mechanism of Taste Stimulation:
Interaction of taste substances with receptors on microvilli
Signal transduction pathways for Umami, Sweet, Bitter, Sour, and Salty tastes
Taste Sensitivity and Adaptation:
Decrease in sensitivity with age
Rapid adaptation of taste sensation
Role of Saliva in Taste:
Dissolution of tastants to reach receptors
Washing away the stimulus
Taste Preferences and Aversions:
Mechanisms behind taste preference and aversion
Influence of receptors and neural pathways
Impact of Sensory Nerve Damage:
Degeneration of taste buds if the sensory nerve fiber is cut
Abnormalities of Taste Detection:
Conditions: Ageusia, Hypogeusia, Dysgeusia (parageusia)
Causes: Nerve damage, neurological disorders, infections, poor oral hygiene, adverse drug effects, deficiencies, aging, tobacco use, altered neurotransmitter levels
Neurotransmitters and Taste Threshold:
Effects of serotonin (5-HT) and norepinephrine (NE) on taste sensitivity
Supertasters:
25% of the population with heightened sensitivity to taste, especially bitterness
Increased number of fungiform papillae
Title: Sense of Smell
Presenter: Dr. Faiza, Assistant Professor of Physiology
Qualifications:
MBBS (Best Graduate, AIMC Lahore)
FCPS Physiology
ICMT, CHPE, DHPE (STMU)
MPH (GC University, Faisalabad)
MBA (Virtual University of Pakistan)
Learning Objectives:
Describe the primary categories of smells and the concept of odor blindness.
Explain the structure and location of the olfactory membrane and mucosa, including the types and roles of cells involved in olfaction.
Describe the pathway and mechanisms of olfactory signal transmission from the olfactory receptors to the brain.
Illustrate the biochemical cascade triggered by odorant binding to olfactory receptors, including the role of G-proteins and second messengers in generating an action potential.
Identify different types of olfactory disorders such as anosmia, hyposmia, hyperosmia, and dysosmia, including their potential causes.
Key Topics:
Olfactory Genes:
3% of the human genome accounts for olfactory genes.
400 genes for odorant receptors.
Olfactory Membrane:
Located in the superior part of the nasal cavity.
Medially: Folds downward along the superior septum.
Laterally: Folds over the superior turbinate and upper surface of the middle turbinate.
Total surface area: 5-10 square centimeters.
Olfactory Mucosa:
Olfactory Cells: Bipolar nerve cells derived from the CNS (100 million), with 4-25 olfactory cilia per cell.
Sustentacular Cells: Produce mucus and maintain ionic and molecular environment.
Basal Cells: Replace worn-out olfactory cells with an average lifespan of 1-2 months.
Bowman’s Gland: Secretes mucus.
Stimulation of Olfactory Cells:
Odorant dissolves in mucus and attaches to receptors on olfactory cilia.
Involves a cascade effect through G-proteins and second messengers, leading to depolarization and action potential generation in the olfactory nerve.
Quality of a Good Odorant:
Small (3-20 Carbon atoms), volatile, water-soluble, and lipid-soluble.
Facilitated by odorant-binding proteins in mucus.
Membrane Potential and Action Potential:
Resting membrane potential: -55mV.
Action potential frequency in the olfactory nerve increases with odorant strength.
Adaptation Towards the Sense of Smell:
Rapid adaptation within the first second, with further slow adaptation.
Psychological adaptation greater than receptor adaptation, involving feedback inhibition from the central nervous system.
Primary Sensations of Smell:
Camphoraceous, Musky, Floral, Pepperminty, Ethereal, Pungent, Putrid.
Odor Detection Threshold:
Examples: Hydrogen sulfide (0.0005 ppm), Methyl-mercaptan (0.002 ppm).
Some toxic substances are odorless at lethal concentrations.
Characteristics of Smell:
Odor blindness for single substances due to lack of appropriate receptor protein.
Behavioral and emotional influences of smell.
Transmission of Olfactory Signals:
From olfactory cells to glomeruli in the olfactory bulb, involving lateral inhibition.
Primitive, less old, and new olfactory systems with different path
Couples presenting to the infertility clinic- Do they really have infertility...Sujoy Dasgupta
Dr Sujoy Dasgupta presented the study on "Couples presenting to the infertility clinic- Do they really have infertility? – The unexplored stories of non-consummation" in the 13th Congress of the Asia Pacific Initiative on Reproduction (ASPIRE 2024) at Manila on 24 May, 2024.
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Flu Vaccine Alert in Bangalore Karnatakaaddon Scans
As flu season approaches, health officials in Bangalore, Karnataka, are urging residents to get their flu vaccinations. The seasonal flu, while common, can lead to severe health complications, particularly for vulnerable populations such as young children, the elderly, and those with underlying health conditions.
Dr. Vidisha Kumari, a leading epidemiologist in Bangalore, emphasizes the importance of getting vaccinated. "The flu vaccine is our best defense against the influenza virus. It not only protects individuals but also helps prevent the spread of the virus in our communities," he says.
This year, the flu season is expected to coincide with a potential increase in other respiratory illnesses. The Karnataka Health Department has launched an awareness campaign highlighting the significance of flu vaccinations. They have set up multiple vaccination centers across Bangalore, making it convenient for residents to receive their shots.
To encourage widespread vaccination, the government is also collaborating with local schools, workplaces, and community centers to facilitate vaccination drives. Special attention is being given to ensuring that the vaccine is accessible to all, including marginalized communities who may have limited access to healthcare.
Residents are reminded that the flu vaccine is safe and effective. Common side effects are mild and may include soreness at the injection site, mild fever, or muscle aches. These side effects are generally short-lived and far less severe than the flu itself.
Healthcare providers are also stressing the importance of continuing COVID-19 precautions. Wearing masks, practicing good hand hygiene, and maintaining social distancing are still crucial, especially in crowded places.
Protect yourself and your loved ones by getting vaccinated. Together, we can help keep Bangalore healthy and safe this flu season. For more information on vaccination centers and schedules, residents can visit the Karnataka Health Department’s official website or follow their social media pages.
Stay informed, stay safe, and get your flu shot today!
Tom Selleck Health: A Comprehensive Look at the Iconic Actor’s Wellness Journeygreendigital
Tom Selleck, an enduring figure in Hollywood. has captivated audiences for decades with his rugged charm, iconic moustache. and memorable roles in television and film. From his breakout role as Thomas Magnum in Magnum P.I. to his current portrayal of Frank Reagan in Blue Bloods. Selleck's career has spanned over 50 years. But beyond his professional achievements. fans have often been curious about Tom Selleck Health. especially as he has aged in the public eye.
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Introduction
Many have been interested in Tom Selleck health. not only because of his enduring presence on screen but also because of the challenges. and lifestyle choices he has faced and made over the years. This article delves into the various aspects of Tom Selleck health. exploring his fitness regimen, diet, mental health. and the challenges he has encountered as he ages. We'll look at how he maintains his well-being. the health issues he has faced, and his approach to ageing .
Early Life and Career
Childhood and Athletic Beginnings
Tom Selleck was born on January 29, 1945, in Detroit, Michigan, and grew up in Sherman Oaks, California. From an early age, he was involved in sports, particularly basketball. which played a significant role in his physical development. His athletic pursuits continued into college. where he attended the University of Southern California (USC) on a basketball scholarship. This early involvement in sports laid a strong foundation for his physical health and disciplined lifestyle.
Transition to Acting
Selleck's transition from an athlete to an actor came with its physical demands. His first significant role in "Magnum P.I." required him to perform various stunts and maintain a fit appearance. This role, which he played from 1980 to 1988. necessitated a rigorous fitness routine to meet the show's demands. setting the stage for his long-term commitment to health and wellness.
Fitness Regimen
Workout Routine
Tom Selleck health and fitness regimen has evolved. adapting to his changing roles and age. During his "Magnum, P.I." days. Selleck's workouts were intense and focused on building and maintaining muscle mass. His routine included weightlifting, cardiovascular exercises. and specific training for the stunts he performed on the show.
Selleck adjusted his fitness routine as he aged to suit his body's needs. Today, his workouts focus on maintaining flexibility, strength, and cardiovascular health. He incorporates low-impact exercises such as swimming, walking, and light weightlifting. This balanced approach helps him stay fit without putting undue strain on his joints and muscles.
Importance of Flexibility and Mobility
In recent years, Selleck has emphasized the importance of flexibility and mobility in his fitness regimen. Understanding the natural decline in muscle mass and joint flexibility with age. he includes stretching and yoga in his routine. These practices help prevent injuries, improve posture, and maintain mobilit
micro teaching on communication m.sc nursing.pdfAnurag Sharma
Microteaching is a unique model of practice teaching. It is a viable instrument for the. desired change in the teaching behavior or the behavior potential which, in specified types of real. classroom situations, tends to facilitate the achievement of specified types of objectives.
MANAGEMENT OF ATRIOVENTRICULAR CONDUCTION BLOCK.pdfJim Jacob Roy
Cardiac conduction defects can occur due to various causes.
Atrioventricular conduction blocks ( AV blocks ) are classified into 3 types.
This document describes the acute management of AV block.
Prix Galien International 2024 Forum ProgramLevi Shapiro
June 20, 2024, Prix Galien International and Jerusalem Ethics Forum in ROME. Detailed agenda including panels:
- ADVANCES IN CARDIOLOGY: A NEW PARADIGM IS COMING
- WOMEN’S HEALTH: FERTILITY PRESERVATION
- WHAT’S NEW IN THE TREATMENT OF INFECTIOUS,
ONCOLOGICAL AND INFLAMMATORY SKIN DISEASES?
- ARTIFICIAL INTELLIGENCE AND ETHICS
- GENE THERAPY
- BEYOND BORDERS: GLOBAL INITIATIVES FOR DEMOCRATIZING LIFE SCIENCE TECHNOLOGIES AND PROMOTING ACCESS TO HEALTHCARE
- ETHICAL CHALLENGES IN LIFE SCIENCES
- Prix Galien International Awards Ceremony
Ozempic: Preoperative Management of Patients on GLP-1 Receptor Agonists Saeid Safari
Preoperative Management of Patients on GLP-1 Receptor Agonists like Ozempic and Semiglutide
ASA GUIDELINE
NYSORA Guideline
2 Case Reports of Gastric Ultrasound
2. Introduction
• Drinking water must be
visually acceptable, clear and without any
disagreeable taste or odour.
Should be free from chemical toxins and pathogenic
microorganisms.
• Many major human diseases, e.g, typhoid, cholera, other
diarrhoeal diseases, poliomyelitis and viral hepatitis A
and E are waterborne.
• These pathogens reach water sources through fecal or
sewage pollution
3. Bacteriology of Water
Water is said to be contaminated or polluted ,when
it is contaminated with sewage or other
excreted matter from humans and animals
that contains infective and parasitic agents,
poisonous chemical substances, and
industrial or other wastes.
4. Bacterial Flora in Water
• Bacterial flora in water can be classified
into three groups.
1. Natural water bacteria:
2. Soil bacteria:
3. Sewage bacteria:
5. Bacterial Flora in Water
Natural water bacteria:
• These are the bacteria that are commonly found in
water, free from
gross pollution
• e.g- Micrococcus, Pseudomonas, Serratia,
Flavobacterium, Acinetobacter.
Soil bacteria:
• These are the bacteria that are not normal inhabitants of
water but are found after being washed into the water
during rains
• e.g- Aerobic spore forming bacilli and Enterobacter
species.
6. Sewage bacteria:
• These are the bacteria that are not normal
inhabitants of water but are found in water after
being contaminated with sewage
• e.g, E. coli, Clostridium perfringens.
• These bacteria include those which are the normal
inhabitants of the intestine of humans and animals.
• These also include the bacteria that live mainly on
decomposed organic matter of either plant or animal
origin.
7. Bacterial flora in water
Source of water Bacteria
Natural water bacteria Micrococcus, Pseudomonas,
Acinetobacter, Serratia, Alcaligenes, and
Flavobacterium
Soil bacteria washed into water Bacillus subtilis, Enterobacter cloacae, and
Enterobacter aerogenes
Sewage bacteria:
Proper sewage bacteria, Clostridium perfringens, Proteus species
Intestinal flora through sewage Escherichia coli, Enterococcus fecalis,
Proteus species, Klebsiella species,
Clostridium perfringens
8. Factors Determining the Number of Bacteria in Water
Salinity:
more is the salinity, lesser is the number of bacteria.
However, some halophilic bacteria survive better in saline
water.
Acidity:
Acidity of water has a deleterious effect on most of the
bacteria.
Temperature:
Body temperature usually favours survival of the bacteria.
However, in the presence of organic materials, bacteria
tend to multiply even at high temperature.
Light:
Sunlight with the wavelength of 300–400nm is highly
bactericidal, provided water is clear and static. The
bactericidal effect is reduced due to the presence of
organic matter and due to movement in water.
9. Factors Determining the Number of Bacteria in Water
Storage:
decreases bacterial count in stored water due to
sedimentation.
Organic matter:
When organic matter is plenty, the microorganisms
tend to multiply and are present in large numbers
whereas when it is less, the organisms are few.
Type of water:
Surface water is more likely to be contaminated than
the deep water. The later is usually pure.
10. • Water-Borne Microorganisms
Supply of drinking water is contaminated with sewage or
other excreted matter from humans and animals;
it can transmit a wide number of pathogens that includes
bacteria, viruses, and parasites.
11. Water-borne pathogens
Bacteria Vibrio cholerae; Salmonella Typhi,
Salmonella Paratyphi A, B, and C;
Shigella spp.; Escherichia coli;
Yersinia enterocolitica;
and Campylobacter jejuni
Viruses Hepatitis A virus, Hepatitis E virus,
poliomyelitis virus, rotavirus, and
Norwalk virus
Protozoa Entamoeba histolytica, Giardia
lamblia, Cryptosporidium spp.,
Cyclospora spp., Isospora spp., and
Balantidium coli
Helminthes Ascaris lumbricoides, Trichuris
trichiura, and Enterobius vermicularis
12. Bacteriological Examination of water
Supplies of drinking water contaminated with sewage or
other excreted matter from man and animals may cause
diseases (such as typhoid, cholera, campylobacteriosis,
amoebiasis and helminthiasis.) there fore need of
bacteriological examination.
It is impractical to attempt directly to detect the presence
of all different kinds of water borne pathogens, any of
which may be present intermittently.
Instead, reliance is placed on testing the supply for
microorganisms which indicate that fecal pollution has
taken place.
13. The indicators are usually common intestinal
commensal bacteria which are universally present in,
and excreted in large numbers by man and animals and
are rarely found in other sources.
Their presence indicates that the
fecal matter has entered the water supply,
fecal bacteria have not been killed or removed by
purification process and
supply is therefore liable to contamination with
dangerous intestinal pathogens.
14. Indicator organisms
Microorganisms for use as indicators of faecal
pollution should satisfy several criteria.
They should be present in faeces in greater numbers than
other pathogen yet be unable to proliferate in water to any
extent.
Moreover, they should be more resistant than pathogens to
the stresses of the aquatic environment and disinfection
processes.
Usually a number of indicator organisms are sought.
15. Indicator organisms
1. Coliforms (presumptive
coliforms)
2. Faecal (Thermotolerant)
coliforms
3. E. coli or ‘fecal E. coli’
4. Faecal streptococci
5. Sulphite – reducing clostridia
6. Pseudomonas aeruginosa
7. Bacteriophage that infect
Escherichia coli.
16. Coliforms (presumptive coliforms)
• are the bacteria that occur in large no. in feces &
sewage, but
• are also found in the environment in the absence
of fecal contamination.
• their presence in the water does not necessarily
signify fecal contamination.
• are the members of family Enterobacteriaceae,
• grow in the presence of bile salts and produce
acid and gas from lactose within 48 hr at 37 0C.
17. Cont...
• In order to include bacteria that do not ferment
lactose, the definition now applying in the UK
has been amended.
Now, the coliforms are defined as members of
the Enterbacteriaceae capable of growing at 37
0C that normally possess β- galactosidase.
18. Cont.....
This change in definition permits –
Introduction of rapid methods of enzyme
detection to indicate the presence of
coliforms.
However, the inclusion of ‘normally’ will
cause some β- galactosidase negative strains
to be classified as coliforms.
As a consequence, more water samples
will now fail because of higher total coliform
counts.
20. Fecal ( or thermotolerant)
coliforms
Confirm the criteria for coliforms organisms, but
are capable of growing (or expressing their
properties) at 440C.
The presence of these organisms in the water
implies that serious contamination has occurred.
21. Escherichia coli or ‘Fecal E. coli'
E. coli is regarded as the essential indicator of fecal
pollution of human and animal origin.
It Is defined as a thermotolerant coliforms which
ferment lactose (or mannitol) with production of acid
& gas within 24 h.
Also form indole from tryptophan at this
temperature.
Does not survive in water for long time therefore, is
the best indicator of recent fecal pollution of water.
22. Fecal streptococci
Are the gram (+), catalase (-), cocci from the GIT of man
and animals.
Occasionally may be found in food & environmental
samples, not known to be contaminated with feces.
Have Lancefield group D Antigen.
Hydrolyze esculin,
Can grow at 450 C in the presence of azide and 40 %
bile.
Can survive at 600C for 30 minutes.
23. Fecal streptococci cont....
genus Enterococus - E. faecalis & E. faecium being the
most common species in the human faeces.
Those cocci that do not have above mentioned properties
are either S. bovis or S. equinus which are predominant in
ruminants & horses respectively.
Fecal streptococci (such as the Enterococcus species)
may be present in water samples, but usually only for short
durations.
Hence , if fecal streptococci are present in water sample, it
suggests recent fecal contamination of water.
24. Sulphite Reducing Clostridia
These are the members of the genus Clostridium.
These bacilli reduce sulphite to sulphide.
The most important organism in the context of water
microbiology is C. perfringens.
Presence of this organisms or their spores, indicate
remote or intermittent fecal contamination.
25. Pseudomonas aeruginosa
can multiply rapidly in the wide variety of aquatic
environment,
not always found in the human feces & therefore
Is not very good indicator of fecal contamination.
However, it is an important pathogen encountered in
hospital environment and hence
Its detection in water supplies of hospitals and food
establishments has significant value.
27. Collection of water sample
1. For collection,
use heat sterilised bottles
containing a sufficient volume of
sodium thiosulphate (to neutralise the
bactericidal effect of any chlorine in water.)
Each bottle of 100 ml capacity
should contain 0.1 ml of fresh 1.8
% (w/v) aqueous solution of
sodium thiosulphate.
28. Collection of sample from taps
When collecting the samples from tap,
Exercise extreme care to avoid contaminating it with
bacteria from the environment.
Allow water to run for 2 to 3 minutes before collecting it
in the bottle.
29. Collection of samples from a tap cont….
• In regular use:
Allow the water to run for 2-3 minutes.
• Not in regular use:
Sterilize the tap by heating it either with a blow lamp or
with an ignited piece of cotton soaked in spirit, until it is
unbearably hot to the touch
Cool the tap by allowing the water to run before
sampling.
For collection hold the bottle near the base with one
hand
Remove the stopper & paper cover together & hold in
the fingers
Fill the bottle from a gentle stream of the water from the
tap
30. Collection of samples from
rivers, lakes or reservoirs
When sampling from streams or lakes,
open the bottle at a depth of about 30 cm with its mouth
facing the current.
Eensure that water entering the bottle has not been in
contact with the hand.
if there is no current (e.g. lake), move the bottle
horizontally, so that water flows into it
bring the bottle to the surface, replace the stopper over
it.
31. Collection of samples from
wells/depth
a heavy bottle with lid having
two cords attached one to the neck & other
to the stopper is used.
lower the bottle to the required depth.
fill it by jerking out the stopper by means of the attached
cord.
raise the bottle quickly to the surface.
replace the stopper.
32. Transportation & storage of samples
Collect at least 100ml in each bottle.
After collection-
label it with full details of the source of the water and
time and date of collection and
deliver it to laboratory as quickly as possible, at least
within 6 hr, keeping it in a cool container and
protected from light.
33. Counting of indicator organisms
It is necessary not only to attempt to detect the presence
of the indicator bacteria, but also to innumerate them.
Greater their number, the greater is the probability of
infection from the supply.
As the number of indicator bacteria in the water may be
small, large volumes of water have to be cultured.
Two methods are available for this purpose,
Multiple tube method and
Membrane filtration method.
35. Advantages
Membrane filtration has advantages over the multiple tube
test
Require less labour and materials and
gives directly quantitative results quickly,
so that any corrective action required to render the
supply safe may be taken sooner.
Multiple tube methods has the advantages that
it can show gas formation by the bacteria and
is suitable for the examination of turbid waters
containing small numbers of the indicator bacteria.
36. Cont...
• Waters containing numerous sapropyhtic
bacteria that might supress the growth of the
coliform.
• Membrane filtration tends to give lower counts
and more false negative results with E. Coli than
the multiple tube methods. (Tillett et al 1988).
37. Multiple tube test
Measured volumes (50ml and 10ml) of water and dilution
of water are added to a series of tubes or bottles
containing-
equal volume of double strength MacConkey’s broth
with neutral red.
Also 1ml of water is added to 5ml of ss medium.
Media is incubated aerobically at 370C and examined
after 24 hrs.
The media having the indicator bacteria show growth
with production of acid & gas and characteristic colour
change, (which are absent in those receiving an sample
of water without indicator bacteria.)
38. indicated by its colour change to pink with the formation
of acid from lactose in the broth.
An inverted Durham tube is placed in each bottle or
tube of the medium.
Bacteria capable of growth and the production of acid
and gas in MacConkey’s broth are assumed to be
coliform bacilli, i.e, ‘presumptive coliform’.
From the numbers and distribution of positive and
negative reactions, the most probable number (MPN) of
indicator organism in the sample estimated.
by reference to statistical tables( McCrady’s table).
39. Media:
Mac Conkey broth, double strength:
Peptone ------------------ 40g
Sod. Taurocholate------10g
Lactose--------------------20g
NaCl-----------------------10g
Neutral red----------------0.15g,
D/W------------------------1 litre
pH: 7.4
distribute in 10ml & 50ml volumes in the tubes with Durham
tube, autoclave at 1150C for 10minutes.
Mac Conkey broth, Single strength:
dilute DS medium with an equal vol. of D/W
distribute in 5ml vol. in the tubes with Durham tube, autoclave at
1150C for 10 minutes.
40. Alternative media
An alternative selective indicator medium is lauryl
tryptose broth.
In this fermentation of lactose is judged by gas
formation.
Indole production is to be observed by the addition of
indole reagent after growth.
41. Tryptose ---------------------
Lactose-----------------------
Sodium chlorode------------
Dipotassium
hydrogen phosphate--------
Potassium
dihydrogen phosphate-----
-
Sodium lauryl sulphate,
D/W---------------------------
40 g
10 g
10 g
5.5 g
5.5 g
0.2 g
1 litre
Lauryl tryptose broth, double strength
(recommended as an alternative to Mac Conkey broth by
American Public Health Association)
42. Procedure
For water of good quality:
1 tube containing 50ml DS medium Aseptically inoculate with corresponding vol.of
5 tube containing10 ml DS medium well mixed water samples
For water of doubtful quality:
1 tube containing 50ml DS medium Aseptically inoculate with corresponding vol.of
5 tube containing10 ml DS medium well mixed water samples.
5tube containing 5ml SS medium --------- inoculate with 1ml. of well mixed water
samples
43. Procedure
For water known to be polluted:
5 tube containing10 ml DS medium----- inoculate with
corresponding vol. of water
5tube containing 5ml SS medium------- inoculate
with 1ml. of well mixed water samples
Prepare 1/10 dil. & higher 10 fold dil. of water in
Ringer’s solution
Two sets of 5 tube containing 5ml SS medium---
inoculate 1 set with 1ml of 1/10 diluted water & other
sets with 1ml of any higher dilution.
44. Procedure cont...
Incubate the inoculated media aerobically at 370C.
After 24h & 48h of incubation, inspect the media.
Note the no. of cultures of each vol. of water that shows the
production of acid (colour change) & gas (a bubble large
enough to fill the concavity at top of Durham tube).
These acid and gas producing cultures are considered
‘presumptive positive’ growths of colliform bacilli.
Cultures not showing both acid & gas at 48h ---- negative.
Read the probable no. of coliforms per 100ml from the MPN
(most probable number) table of Mac Crady.
45.
46.
47. Confirmed coliform count: Eijkman test
• Principle:
some spore bearing bacteria give false positive reaction
in the presumptive coliform test.
Their presence is most likely to be misleading in the
examination of chlorinated drinking water. (spores are
more resistant to chlorine)
It is necessary, therefore, to confirm the presence of true
(faecal) coliform bacilli in each vessel showing a
presumptive positive reaction.
and it may be necessary to determine whether these
coliform bacilli are E. Coli.
48.
49. Interpretation:
Gas production in tubes incubated at 370C for 48h----
confirms coliforms.
Gas & indole production in tubes incubated at 440C
for 24h ---- confirms E.coli.
Formation of indole at 44 0C without the formation of
gas from lactose at 44 0C , even if acid is formed-------
-other than E. coli.
For greater assurance, the colonies may be
submitted to oxidase test to exclude the possibility of
Pseudomonas, aeromonas, which gives (+)ve
reaction in this test.
Refer to the Mac Crady’s probability table & read off
the MPN of confirmed coliform count & confirmed E.
coli per 100ml of water.
50. Membrane filtration method
In this method, a measured volume of the water sample
is filtered through a membrane filter( 47mm diameter and
0.45μm pore size) small enough to retain the indicator
bacteria to be counted.
The membrane is then placed and incubated on a
selective indicator medium, so that the indicator bacteria
grow into colonies on its upper surface.
These colonies, which are recognised by their colour,
morphology and ability to grow on the selective, are
countered.
51. Total coliform (presumptive coliform) count by
filtration
For this test the membrane are cultured on pads soaked
with membrane lauryl sulphate broth or an equivalent
medium, which is inhibitory to many non-coliform
bacteria, the coliforms grow as yellow-coloured colonies.
Steps:
1. A measured volumes of well mixed water samples is
filtered through a membrane with a pore size of 0.45µ.
2. The membrane is then placed on a selective indicator
medium (lauryl sulphate medium).
3.Then we incubate it aerobically at 30 0c for 4 hrs followed
by 14 hrs at 37 0c.
52. 4. with chlorinated water, incubate at 25 0c for 6h followed
by 18h at 35 0c.
5. immediately on removal from incubator, count all the
yellow colonies on the surface of membrane irrespective
of size .
6. with reference to volume of water filtered, express the
result as number of presumptive coliforms per 100ml of
samples.
53. Plate count
It expresses the number of all colony forming bacteria in
1ml of water.
it provides information regarding amount & type of the
organic matter in water.
This may be useful in indicating the efficiency of the
processes used for water treatment.
Also useful in assessing the suitability of water for large
scale production of food and drink.
Separate plate cultures are incubated at 20-22 0c and at
37 0c.
At 20-22 0c grows mainly the natural saprophytes of soil
and water.
At 37 0c grows mainly parasitic bacteria derived from
human and animal excretions.
54. Classification of the quality of drinking water
based on bacteriological tests
Presumptive
coliform count
per 100 ml
(MPN)
E. Coli count per
100 ml
Class 1
Excellent
0 0
Class 2
Satisfactory
1-3 0
Class 3
suspicious
4-10 0
Class 4
Unsatisfactory
> 10 1 or more