Potentially pathogenic features of heterotrophic plate count bacteria isolated from treated and untreated drinking water

摘要: Heterotrophic plate counts (HPCs) are commonly used to assess the general microbiological quality of drinking water. Drinking water specifications worldwide recommend HPC limits from 100 500 cfu ml(-1). A number recent studies revealed evidence that these bacteria may not be as harmless generally accepted. It appears immuno-compromised individuals particularly at risk. This would include very young and old patients with diseases such AIDS on therapy for purposes organ transplantation cancer treatment. In this study, 339 bacterial colonies were isolated random selected treated untreated in South Africa using routine heterotrophic count tests. a first step screen potentially pathogenic properties, 188 (55.5%) isolates showed alpha- or beta-haemolysis human- horse-blood agar media. Subsequent analysis haemolytic enzymatic properties associated pathogenicity presence chondroitinase 5.3% isolates, coagulase 16.0%, DNase 60.6%, elastase 33.0%, fibrinolysin 53.7%, gelatinase 62.2%, hyaluronidase 21.3%, lecithinase 47.9%, lipase 54.8% proteinase 64.4%. Fluorescein pyocyanin produced by any isolates. Among 77.7% resistant oxacillin 1 microg, 59.6% penicillin G 2 units, 47.3% 10 54.3% ampicillin microg 43.1% 25 microg. Cell culture 96% cytotoxic HEp-2 cells, 98.9% 181 adhered Caco-2 cells. cells invaded 43.6%, 49.7%, The invasion index ranged 1.9 x 10(-1) 8.9 10(-6), whereas varied between 7.7 10(-2) 8.3 10(-6). most genera features Aeromonas, Acinetobacter, Aureobacterium, Bacillus, Chryseobacterium, Corynebacterium, Klebsiella, Moraxella, Pseudomonas, Staphylococcus, Tsukamurella Vibrio. results obtained study support earlier findings detected HPCs These agreement some epidemiological studies, which indicated an association incidence gastroenteritis consumers. However, extent health risk concerned needs defined more detail meaningful revision guidelines