Inhibition of growth ofLegionella species by heterotrophic plate count bacteria isolated from chlorinated drinking water

1990 ◽  
Vol 21 (2) ◽  
pp. 139-143 ◽  
Author(s):  
Simon Toze ◽  
Lindsay I. Sly ◽  
Ian C. MacRae ◽  
John A. Fuerst
Keyword(s):  
Drinking Water ◽  
Plate Count ◽  
Heterotrophic Plate Count ◽  
Inhibition Of Growth ◽  
Chlorinated Drinking Water

scholarly journals Determination of cytotoxicity and invasiveness of heterotrophic plate count bacteria isolated from drinking water

2002 ◽  
Vol 2 (3) ◽  
pp. 115-122 ◽  
Author(s):  
D. Pavlov ◽  
C.M.E. de Wet ◽  
W.O.K. Grabow ◽  
M.M. Ehlers
Keyword(s):  
Drinking Water ◽  
Health Risk ◽  
Heterotrophic Bacteria ◽  
Penicillin G ◽  
Plate Count ◽  
Heterotrophic Plate Count ◽  
Water Supplies ◽  
Plate Counts ◽  
Study Support ◽  
Heterotrophic Plate Counts

Evidence has been presented that some heterotrophic bacteria often detected in drinking water supplies possess features associated with pathogenicity. This suggests that even the low numbers of heterotrophic bacteria considered acceptable by drinking water specifications may constitute a health risk, particularly to immunocompromised consumers. In this study, 339 bacteria were isolated at random from routine heterotrophic plate count (HPC) tests on selected drinking water supplies in South Africa. In a first screen for potentially pathogenic properties, 188 of the isolates (55.5%) displayed a- or b-haemolysis on blood agar. Further analysis of the haemolytic isolates for enzymes associated with virulence revealed the presence of chondroitinase (5.3%), coagulase (16.0%), DNase (60.6%), elastase (33.0%), fibrinolysin (53.7%), gelatinase (62.2%), hyaluronidase (21.3%), lecithinase (47.9%), lipase (54.8%) and proteinase (64.4%) of the isolates. No fluorescein or pyocyanin was detected in any of the isolates. Among the haemolytic isolates 68.6% were resistant to oxacillin (1 μg), 59.6% to penicillin G (2 units), 47.3% to penicillin G (10 units), 53.7% to ampicillin (10 μg) and 42.6% to ampicillin (25 μg). Cytotoxicity, invasiveness and adherence properties of the haemolytic isolates was determined on HEp-2 and Caco2 cell lines. Among the haemolytic isolates 96% were cytolytic on the HEp-2 cell line. All the haemolytic isolates adhered to HEp-2 and Caco2 cells but gram-negative isolates tended to adhere in larger numbers than gram-positive isolates. HEp-2 cells were invaded by 42% of the haemolytic isolates. Heterotrophic bacteria, which most frequently revealed the above features associated with pathogenicity included species of the following genera: Aeromonas, Acinetobacter, Aureobacterium, Bacillus, Klebsiella, Moraxella, Pseudomonas, Staphylococcus, Tsukamurella and Vibrio. The results obtained in this study support earlier indications that bacteria detected by routine heterotrophic plate counts on drinking water supplies may include bacteria associated with potentially pathogenic properties. The extent to which these bacteria in drinking water supplies may constitute a health risk remains to be investigated.

scholarly journals Pathogenic features of heterotrophic plate count bacteria from drinking-water boreholes

2016 ◽  
Vol 14 (6) ◽  
pp. 890-900 ◽  
Author(s):  
Suranie Horn ◽  
Rialet Pieters ◽  
Carlos Bezuidenhout
Keyword(s):  
Drinking Water ◽  
Extracellular Enzymes ◽  
Alcaligenes Faecalis ◽  
Gastric Fluid ◽  
Plate Count ◽  
Simulated Gastric Fluid ◽  
Heterotrophic Plate Count ◽  
Pathogenic Potential ◽  
Borehole Water ◽  
Human Intestinal Cells

Evidence suggests that heterotrophic plate count (HPC) bacteria may be hazardous to humans with weakened health. We investigated the pathogenic potential of HPC bacteria from untreated borehole water, consumed by humans, for: their haemolytic properties, the production of extracellular enzymes such as DNase, proteinase, lipase, lecithinase, hyaluronidase and chondroitinase, the effect simulated gastric fluid has on their survival, as well as the bacteria's antibiotic-susceptible profile. HuTu-80 cells acted as model for the human intestine and were exposed to the HPC isolates to determine their effects on the viability of the cells. Several HPC isolates were α- or β-haemolytic, produced two or more extracellular enzymes, survived the SGF treatment, and showed resistance against selected antibiotics. The isolates were also harmful to the human intestinal cells to varying degrees. A novel pathogen score was calculated for each isolate. Bacillus cereus had the highest pathogen index: the pathogenicity of the other bacteria declined as follows: Aeromonas taiwanensis>Aeromonas hydrophila>Bacillus thuringiensis>Alcaligenes faecalis > Pseudomonas sp. >Bacillus pumilus>Brevibacillus sp. >Bacillus subtilis>Bacillus sp. These results demonstrated that the prevailing standards for HPCs in drinking water may expose humans with compromised immune systems to undue risk.

Eubacterial 16S-rDNA amplicon profiling: a rapid technique for comparison and differentiation of heterotrophic plate count communities from drinking water

2004 ◽  
Vol 92 (3) ◽  
pp. 333-345 ◽  
Author(s):  
Andreas H. Farnleitner ◽  
Franziska Zibuschka ◽  
Martina M. Burtscher ◽  
Gerhard Lindner ◽  
Georg Reischer ◽  
...  
Keyword(s):  
Drinking Water ◽  
16S Rdna ◽  
Plate Count ◽  
Heterotrophic Plate Count ◽  
Rapid Technique

Effects of disinfectants and particles on occurrence of different microorganisms in drinking water distribution systems

2021 ◽  
Author(s):  
Lixin Huo ◽  
Linlin Pan ◽  
Ruya Chen ◽  
Baoyou Shi ◽  
Haibo Wang ◽  
...  
Keyword(s):  
Drinking Water ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution Systems ◽  
Plate Count ◽  
Opportunistic Pathogens ◽  
Heterotrophic Plate Count ◽  
Total Coliforms ◽  
Drinking Water Distribution Systems ◽  
Drinking Water Distribution

Effects of disinfectants and particles on occurrence of different bacteria, including total coliforms, heterotrophic plate count (HPC), different opportunistic pathogens (OPs) and ameba hosts, were investigated in drinking water distribution...

Research on Drinking Water Biological Stability in Water Supply Network

2012 ◽  
Vol 518-523 ◽  
pp. 3735-3739
Author(s):  
Dong Sheng Dai ◽  
Song Hu Li ◽  
Jie Li
Keyword(s):  
Drinking Water ◽  
Organic Carbon ◽  
Yellow River ◽  
Plate Count ◽  
Available Phosphorus ◽  
Biological Stability ◽  
Heterotrophic Plate Count ◽  
Assimilable Organic Carbon ◽  
Jinan City ◽  
Biodegradable Dissolved Organic Carbon

The Assimilable Organic Carbon (AOC), Microbially Available Phosphorus (MAP), Heterotrophic Plate Count (HPC) and Biodegradable Dissolved Organic Carbon (BDOC) of eight sampling points were analyzed for studying the biological stability of drinking water in Jinan. Biological stability of drinking water can standard basically in Jinan city. There had a certain correlation between AOC and HPC. The AOC indicator was gradual increased from April to May and June to July. There may be related to the seasonal change of Yellow River. The control of AOC was an effective way to improve the water quality.

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