Bacteria, coliform

Membrane filter showing colonies of coliform bacteria. The number of colonies are counted and reported as colonies/100 ml of sample. 

One standard test used to determine the presence of the coliform group is called the multiple-tube fermentation technique (sometimes called the presumptive test). If this test indicates the presence of these bacteria, then a confirmed test must be done. If only negative colonies or no colonies develop during this test, it is considered negative otherwise, a completed test must be undertaken. Positive results obtained in the completed test are evidence for the presence of coliform bacteria. Testing methods have been given by the APHA, and the detailed procedures contained therein should be consulted (20). 

Study has proved that these coliform bacteria indicate the presence of human or animal wastes in water. Coliform bacteria naturally exist in the intestines of humans and certain animals. Thus, the presence of these bacteria in water is accepted proof that the water has been contaminated by human or animal wastes. Although such water may contain no pathogens, an infected person, animal or a carrier of disease, could add pathogens at any moment Thus, immediate corrective action must be taken. The presence of coliform bacteria shows water is contaminated by human... 

The water analysis is incomplete unless the number of coliform bacteria present is determined as well. A multiple-tube fermentation technique can be used to enumerate positive presumptive, confirmed, and fecal coliform tests. Results of the tests are expressed in terms of the most probable number (MPN). That is, the count is based on a statistical analysis of sets of tubes in a series of serial dilutions. MPN is related to a sample volume of 100 ml. Thus, an MPN of 10 means 10 coliforms per 100 ml of water. 

Coliform bacteria Non-pathogenic microbes found in fecal matter that indicate the presence of water pollution are thereby a guide to the suitability for potable use. Colloids Very small, finely divided solids (particles that do not dissolve) that remain dispersed in a liquid for a long time due to their small size and electrical charge. 

Leive L (1968) Studies on the permeability change produced in coliform bacteria by ethylenediaminetetraacetate. J Biol Chem 243 2373-2380. 

Bej, A. K. McCarty, S. C. Atlas, R. M. Detection of coliform bacteria and Escherichia coli by multiplex polymerase chain reaction comparison with defined substrate and plating methods for water quality monitoring. Appl. Environ. Microbiol. 1991, 57, 2429-2432. 

Table 19.3 Total aerobic bacterial count, coliform bacteria, Enterobacteriaceae and Enterococcus, Salmonella and E. coll, for lettuce growing in late spring and late summer 2004 (Rattler et al., 2005)...

For the past 50 years the determination of the sanitary quality of water has been based on the enumeration of indicator micro-organisms (e.g. coliform bacteria). The adequacy of coliform enumeration methods for this purpose has been questioned [21]. The current trend of year-round disinfection of waste water effluents and the increasing discharge of both toxic substances and heat from industrial outfalls cast further doubt on the accuracy of biological indicator systems [22]. 

T.A.M.=Total Aerobic Mesophilic bacteria T.A.T.=Total Aerobic Thermophilic bacteria T.An.M.=Total Anaerobic Mesophilic bacteria Coliforms=Total Coliform bacteria... 

Zhang K, Earahbakhsh K (2007) Removal of native coliphages and coliform bacteria from municipal wastewater by various wastewater treatment processes implications to water reuse. Water Res 41 2816-2824... 

Kampfer P, Nienhuser A, Packroff G et al (2008) Molecular identification of coliform bacteria isolated from drinking water reservoirs with traditional methods and the Colilert-18 system. Int J Hyg Environ Health 211(3-4) 374—384... 

Coliform bacteria are common microorganisms found in the intestinal tract of warm-blooded animals and in the soil and plants. The intestinal type is known as fecal coliform bacteria, while the most common type of soil and plant coliform bacteria is the bacterium Aerobacter aerogenes. Fecal coliform bacteria are easy to test for, and they are present in water at any given time and place in much larger numbers than are pathogens. If large numbers of fecal coliform bacteria are present in a sample of water, it is likely that pathogens are present as well. 

In the test for fecal coliform bacteria, a sample of water is incubated at 112°F (44.5°C) for about 24 hours. Ifbacteria are present, the person conducting the test counts the number of colonies formed or looks for carbon dioxide gas in the incubation tube. This test is specific for fecal coliforms because they are members of a group of coliform bacteria known as thermotolerant that survive at temperatures of 112°F (44.5°C) or more other types of coliforms do not. 

Resistance can occur via plasmid-mediated meth-ylation of the receptor site which reduces the binding of the macrolide. Also plasmid-mediated esterase activity, especially in coliform bacteria, can inactivate the macrolides. 

Feng P, Weagant SD, Grant MA (1998) Enumeration of Escherichia coh and the Coliform Bacteria, in Bacteriological Analytical Manual, Edn. 8 - Revision A, Chapter 4, US Eood and Drug Administration... 

Industrial microbiological quality control normally covers the total count of germs, the counts of yeasts and moulds, coliform bacteria and E. colt. In special cases these investigations are complemented by the detection of Staphylococcus aureus, salmonella and listeria. 

Galesloot, T. E., and Hassing, F. (1983). Effect of nitrate and chlorate and mixtures of these salts on the growth of coliform bacteria. Results of model experiments related to gas defects in cheese. Netherlands Milk Dairy J. 37, 1-9. 

---