Nyabing (Western Australia) – Thermotolerant Coliforms

2007/8: Nyabing: 1 Samples with >0 cfu/100mL, 15 sample Max cfu/100mL

“Thermotolerant coliforms should not be detected in any 100 mL sample of drinking water.
If detected in drinking water, immediate action should be taken including investigation of
potential sources of faecal contamination.
GENERAL DESCRIPTION
Coliforms are Gram-negative, non-spore-forming, rod-shaped bacteria that are capable of aerobic and facultative anaerobic growth in the presence of bile salts or other surface active agents with similar growth-inhibiting properties. They are found in large numbers in the faeces of humans and other warm-blooded animals, but many species also occur in the environment.
Thermotolerant coliforms are a sub-group of coliforms that are able to grow at 44.5 ± 0.2°C. E. coli is the most common thermotolerant coliform present in faeces and is regarded as the most specific indicator of recent faecal contamination because generally it is not capable of growth in the environment. In contrast, some other thermotolerant coliforms (including strains of Klebsiella, Citrobacter and Enterobacter) are able to grow in the environment and their presence is not necessarily related to faecal contamination. Thermotolerant coliforms, including E. coli, can ferment lactose (or mannitol) at 44.5 ± 0.2°C with the production of acid within 24 hours.
SOURCE AND OCCURRENCE
Thermotolerant coliforms are normal inhabitants of the intestine, generally present in high numbers in human and animal faeces;. However, environmental thermotolerant coliforms, can occur in natural waters. These organisms are of lesser significance.” ADWG 2011