Detection Of Coliform Bacteria Research Articles

Detection of coliform bacteria and Escherichia coli by multiplex polymerase chain reaction: comparison with defined substrate and plating methods for water quality monitoring

Multiplex polymerase chain reaction (PCR) and gene probe detection of target lacZ and uidA genes were used to detect total coliform bacteria and Escherichia coli, respectively, for determining water quality. In tests of environmental water samples, the lacZ PCR method gave results statistically equivalent to those of the plate count and defined substrate methods accepted by the U.S. Environmental Protection Agency for water quality monitoring and the uidA PCR method was more sensitive than 4-methylumbelliferyl-beta-D-glucuronide-based defined substrate tests for specific detection of E. coli.

Multiplex PCR amplification and immobilized capture probes for detection of bacterial pathogens and indicators in water

Detection of pathogens ( Legionella species) and indicator bacteria (coliform bacteria) was achieved by multiplex (simultaneous) PCR amplification of diagnostic gene sequences and by hybridization to immobilized poly-dT-tailed capture probes using a dot- or slot-blot approach. Complex manipulations of primer concentrations and staggered additions of primers were required in order to achieve equal amplification of multiple genes. Multiplex PCR amplification of two different Legionella genes, one specific for L. pneumophila ( mip) and the other for the genus Legionella (5S rRNA), was achieved by staggered amplification. Multiplex PCR amplification using differing amounts of primers specific for lacZ and lamB genes permitted the detection of coliform bacteria and those associated with human faecal contamination, including the indicator bacterial species E. coli and enteric pathogens Salmonella and Shigella. Hybridization of biotin-labelled amplified DNA, in which the biotin was incorporated during PCR amplification from biotinylated-dUTP, to immobilized 400-dT-tailed capture probes permitted specific and sensitive detection of target gene sequences. The sensitivity of colorimetric detection achieved by PCR amplification of target DNA was at a level equivalent to 1–2 bacterial cells, which is the same level of sensitivity obtained with radioactive detection. The simultaneous amplification of several genes and hybridization to immobilized capture probes with colorimetric detection is an effective, efficient and rapid detection method for various human bacterial pathogens.

Detection of coliform bacteria in water by polymerase chain reaction and gene probes

Polymerase chain reaction (PCR) amplification and gene probe detection of regions of two genes, lacZ and lamB, were tested for their abilities to detect coliform bacteria. Amplification of a segment of the coding region of Escherichia coli lacZ by using a PCR primer annealing temperature of 50 degrees C detected E. coli and other coliform bacteria (including Shigella spp.) but not Salmonella spp. and noncoliform bacteria. Amplification of a region of E. coli lamB by using a primer annealing temperature of 50 degrees C selectively detected E. coli and Salmonella and Shigella spp. PCR amplification and radiolabeled gene probes detected as little as 1 to 10 fg of genomic E. coli DNA and as a few as 1 to 5 viable E. coli cells in 100 ml of water. PCR amplification of lacZ and lamB provides a basis for a method to detect indicators of fecal contamination of water, and amplification of lamB in particular permits detection of E. coli and enteric pathogens (Salmonella and Shigella spp.) with the necessary specificity and sensitivity for monitoring the bacteriological quality of water so as to ensure the safety of water supplies.

Instrumental Detection of Coliform Bacteria for Industrial Control of Drinking Water Quality

Ensuring the sanitary quality of the potable water supply requires continuous control. Traditionally germs indicating faecal contamination are detected as it is difficult to isolate the enumerate pathogen organisms. The purpose of this report is to describe the steps we have taken to manufacture an on-site locatable automatic device "E. Colimetre" as from the definition of requirements. This device can detect one thermoresistant bacterium with a response time below 10 h. The article describes the device and the evaluation procedures.

Automatic detection of coliform bacteria for industrial control of drinking water quality

Ensuring the sanitary quality of the potable water supply requires continuous control. Traditionally germs indicating faecal contamination are detected as it is difficult to isolate the enumerate pathogen organisms. The purpose of this report is to describe the steps we have taken to manufacture an on-site locatable automatic device “E. Colimetre” as from the definition of requirements. This device can detect one thermoresistant bacterium with a response time below 10 h. The article describes the device and the evaluation procedures.

Study of water-borne coliform bacteria by use of desoxycholate agar and violet red bile agar.

The presumptive test of water-borne coliform bacteria by use of desoxycholate agar and violet red bile agar were reviewed experimentally by the procedures indicated in the Standard Methods of Analysis, authorized by the Pharmaceutical Society of Japan. According to the results obtained on 5 kinds of known strains of coliform bacteria and many samples of sewage and sea water, the authors proposed the criteria for detecting coliform bacteria as shown below ; After incubation at 34-36°C for 18-22h on desoxycholate agar, typical colonies appear as round, rice grain like or oval, more than 1 mm in diameter, presenting the color of 1 R 4/14, vivid purplish red ; 1 R 3/10, deep purplish red ; 4 R 3.5/10, deep red or 6 RP 4/13.5, vivid red purple, comparing with the color-standards specified in Japanese Industrial Standard. After incubation at 34-36°C for 18-22h on violet red bile agar, typical colonies appear as round or oval, more than 1 mm in diameter, presenting the color of 1 RP 4/13, vivid red purple or 7.5 P 2.4/8, deep purple

Radiometric Method for the Detection of Coliform Organisms in Water

A new radiometric method for the detection of coliform bacteria in water has been described. The method is based on the release of 14 CO 2 from [ 14 C]lactose by bacteria suspended in growth medium and incubated at 37 C. The evolved 14 CO 2 is trapped by hyamine hydroxide and counted in a liquid scintillation spectrometer. The method permits the detection of 1 to 10 organisms within 6 h of incubation. Coliform bacteria suspended in water for several days recover from starvation and may be quantitated by the proposed method. Bacteria from water samples may also be concentrated by filtration through membrane filters and detected by the radiometric assay.

Radiometric Method for the Detection of Coliform Organisms in Water

A new radiometric method for the detection of coliform bacteria in water has been described. The method is based on the release of (14)CO(2) from [(14)C]lactose by bacteria suspended in growth medium and incubated at 37 C. The evolved (14)CO(2) is trapped by hyamine hydroxide and counted in a liquid scintillation spectrometer. The method permits the detection of 1 to 10 organisms within 6 h of incubation. Coliform bacteria suspended in water for several days recover from starvation and may be quantitated by the proposed method. Bacteria from water samples may also be concentrated by filtration through membrane filters and detected by the radiometric assay.