Water Analysis
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MICROBIOLOGICAL EXAMINATION (9000)
9221 MULTIPLE-TUBE FERMENTATION TECHNIQUE FOR MEMBERS OF THE COLIFORM GROUP*
9221 A. Introduction
The coliform group consists of several genera of bacteria belonging to the family Enterobacteriaceae. The historical definition of this group has been based on the method used for detection (lactose fermentation) rather than on the tenets of systematic bacteriology. Accordingly, when the fermentation technique is used, this group is defined as all facultative anaerobic, gram-negative, non-spore-forming, rod-shaped bacteria that ferment lactose with gas and acid formation within 48 h at 35°C. The standard test for the coliform group may be carried out either by the multiple-tube fermentation technique or presenceabsence procedure (through the presumptive-confirmed phases or completed test) described herein, by the membrane filter (MF) technique (Section 9222) or by the enzymatic substrate coliform test (Section 9223). Each technique is applicable within the limitations specified and with due consideration of the purpose of the examination. Production of valid results requires strict adherence to quality control procedures. Quality control guidelines are outlined in Section 9020. When multiple tubes are used in the fermentation technique, results of the examination of replicate tubes and dilutions are
* Approved by Standard Methods Committee, A–E, 1999; F, 2001. Joint Task Group: (9221C): Eugene W. Rice (chair), Paul S. Berger, James A. Clark, Stephen C. Edberg, Wallace E. Garthright, Nancy H. Hall, Shundar Lin; (9221F): Mark C. Meckes (chair), Paul S. Berger, James A. Clark, Wallace E. Garthright, Nancy H. Hall, Shundar Lin.
MULTIPLE-TUBE FERMENTATION TECHNIQUE (9221)/Standard Total Coliform Fermentation Technique
9-49
reported in terms of the Most Probable Number (MPN) of organisms present. This number, based on certain probability formulas, is an estimate of the mean density of coliforms in the sample. Coliform
MICROBIOLOGICAL EXAMINATION (9000)
9221 MULTIPLE-TUBE FERMENTATION TECHNIQUE FOR MEMBERS OF THE COLIFORM GROUP*
9221 A. Introduction
The coliform group consists of several genera of bacteria belonging to the family Enterobacteriaceae. The historical definition of this group has been based on the method used for detection (lactose fermentation) rather than on the tenets of systematic bacteriology. Accordingly, when the fermentation technique is used, this group is defined as all facultative anaerobic, gram-negative, non-spore-forming, rod-shaped bacteria that ferment lactose with gas and acid formation within 48 h at 35°C. The standard test for the coliform group may be carried out either by the multiple-tube fermentation technique or presenceabsence procedure (through the presumptive-confirmed phases or completed test) described herein, by the membrane filter (MF) technique (Section 9222) or by the enzymatic substrate coliform test (Section 9223). Each technique is applicable within the limitations specified and with due consideration of the purpose of the examination. Production of valid results requires strict adherence to quality control procedures. Quality control guidelines are outlined in Section 9020. When multiple tubes are used in the fermentation technique, results of the examination of replicate tubes and dilutions are
* Approved by Standard Methods Committee, A–E, 1999; F, 2001. Joint Task Group: (9221C): Eugene W. Rice (chair), Paul S. Berger, James A. Clark, Stephen C. Edberg, Wallace E. Garthright, Nancy H. Hall, Shundar Lin; (9221F): Mark C. Meckes (chair), Paul S. Berger, James A. Clark, Wallace E. Garthright, Nancy H. Hall, Shundar Lin.
MULTIPLE-TUBE FERMENTATION TECHNIQUE (9221)/Standard Total Coliform Fermentation Technique
9-49
reported in terms of the Most Probable Number (MPN) of organisms present. This number, based on certain probability formulas, is an estimate of the mean density of coliforms in the sample. Coliform
Bibliography: FENG, P.C.S. & P.A. HARTMAN. 1982. Fluorogenic assays for immediate confirmation of Escherichia coli. Appl. Environ. Microbiol. 43: 1320. HARTMAN, P.A. 1989. The MUG (glucuronidase) test for E. coli in food and water. In A. Balows et al., eds., Rapid Methods and Automation in Microbiology and Immunology. Proc. 5th Intl. Symp. on Rapid Methods and Automation in Microbiology & Immunology, Florence, Italy, Nov. 4 – 6, 1987. FIEDLER, J. & J. REISKE. 1990. Glutaminsauredecarboxylase-schnelltest zur identifikation von Escherichia coli. Z. Ges. Hyg. Grenzgeb. 36:620. SHADIX, L.C. & E.W. RICE. 1991. Evaluation of -glucuronidase assay for the detection of Escherichia coli from environmental waters. Can. J. Microbiol. 37:908. RICE, E.W., C.H. JOHNSON, M.E. DUNNIGAN & D.J. REASONER. 1993. Rapid glutamate decarboxylase assay for detection of Escherichia coli. Appl. Environ. Microbiol. 59:4347. Errata. 1995. Appl. Environ. Microbiol. 61:847. RICE, E.W., C.H. JOHNSON & D.J. REASONER. 1996. Detection of Escherichia coli O157:H7 in water from coliform enrichment cultures. Lett. Appl. Microbiol. 23:179. STANDING COMMITTEE OF ANALYSTS. 1994. Report on Public Health and Medical Subjects No. 71, Methods for the Examination of Waters and Associated Materials, The Microbiology of Water Part 1–Drinking Water. HMSO Books, London, U.K.