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6/2/2015 1 General Water Microbiology Robin Cook FSEA Fall Meeting and Technical Session 10/17/2007.

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Presentation on theme: "6/2/2015 1 General Water Microbiology Robin Cook FSEA Fall Meeting and Technical Session 10/17/2007."— Presentation transcript:

1 6/2/2015 1 General Water Microbiology Robin Cook FSEA Fall Meeting and Technical Session 10/17/2007

2 6/2/2015 2 Introduction Why we do this matters! How we do this matters! This is not just about meeting a regulatory requirement.

3 6/2/2015 3 Overview What are we looking for? Why are we looking?

4 6/2/2015 4 Vocabulary Coliform Bacteria = Gram (-),non-spore- forming, facultative anaerobic, rod-shaped bacteria capable of growth in the presence of bile salts and that ferment lactose with production of gas, acid and aldehyde within 48hrs at 35°C. OR Coliform Bacteria = … possessing the enzyme  -galactosidase which cleaves ONPG resulting in a release of a chromogen. These definitions are operational rather than taxonomic and therefore tied to a method as well.

5 6/2/2015 5 Vocabulary cont. This definition includes Enterobacter aerogenes which is NOT typically associated with the intestine. Depending on which defintion Serratia may or may not be a coliform. Not all species will ferment lactose.

6 6/2/2015 6 Vocabulary Cont. Coliforms are members of the enteric bacteria group also know as the Enterbacteriaceae family. Fecal Coliforms are further defined as thermotolerant coliforms capable of growth with acid and gas formation at 44.5ºC.

7 6/2/2015 7 Enterobacteriaceae Family Klebsiella, Enterobacter, Citrobacter, and Escherichia are classified as coliforms. Escherichia coli, Citrobacter freundii and thermotolerant Klebsiella pneumoniae are classified as fecal coliforms. Non-coliforms include Proteus, Serratia (depending), Yersinia, Shigella, and Salmonella. These are excluded only because they do not usually ferment lactose.

8 6/2/2015 8 Other indicators Fecal Streptococcus: Gram (+) bacteria which is a normal inhabitant of the GI tract of warm-blooded animals. –Only a few are pathogenic –Persist well, but do not reproduce in the environment. –Many isolates are not associated with humans.

9 6/2/2015 9 Other indicators cont. Enterococcus: subgroup of the Fecal Streptococcus –can grow in 6.5% NaCl, at pH 9.6 and at both 10ºC and 45ºC. –Used to check quality of recreational waters

10 6/2/2015 10 Interesting Trivia Ratio of FC:FS –FC:FS > 4.0 human contamination –FC:FS < 0.7 animal contamination –Between suggests a mixed source –Only valid in the 1 st 24 hours, and technology dependent

11 6/2/2015 11 Concerns and Disease: Klebsiella: opportunistic pathogen. Can cause infection in wounds, soft tissue and urinary tract as well as pneumonia in immuno-compromised. Enterobacter, Citrobacter, and Serratia: mostly hospital-related infections –Serratia is particularly prevalent in maternity wards E. coli: septiciema, UTI, neonatal meningitis, gastroenteritis and hemorrhagic colitis. Proteus: UTI and contributes to the formation of kidney stones due to pH change it causes.

12 6/2/2015 12 Continued Yersinia: septicemia, enterocolitis, Bubonic Plague. Shigella: gastrointeritis Salmonella typhi: Typhoid Fever Not in the family but grows in the same conditions: Vibrio cholerae which is what causes cholera in untreated water.

13 6/2/2015 13 Indicator Organisms Associated with the intestinal tract typically in large numbers Found in warm-blooded animals as well as humans yet will die once excreted Death-rate is similar to the pathogenic Salmonella and Shigella Both coliforms and pathogens react in a similar manner during the water purification process.

14 6/2/2015 14 Summary The presence of coliforms indicates a problem BUT, absence does not necessarily mean that there is not a problem Need as much information as possible to make a good decision.

15 6/2/2015 15 References Brock, Thomas D. et al. Biology of Microorganisms 7 th ed. Englewood Cliffs, NJ: Prentice Hall, 1994. Cullimore, D. Roy. Practical Manual of Groundwater Microbiology. Boca Raton, FL: Lewis, 1993. Murry, Patrick R., et al. Medical Microbiology 2 nd ed. St Loius, MO: Mosby, 1994.

16 6/2/2015 16 Any questions?


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