scholarly journals Effect of different heterotrophic plate count methods on the estimation of the composition of the culturable microbial community

PeerJ ◽  
2015 ◽  
Vol 3 ◽  
pp. e862 ◽  
Author(s):  
Eva Theres Gensberger ◽  
Eva-Maria Gössl ◽  
Livio Antonielli ◽  
Angela Sessitsch ◽  
Tanja Kostić
Keyword(s):  
Microbial Community ◽  
Plate Count ◽  
Heterotrophic Plate Count

scholarly journals Effect of variations in heterotrophic plate count methods on bacterial estimation in some sachet water in Calabar Metropolis

2019 ◽  
Vol 1 (2) ◽  
pp. 018-027
Author(s):  
Augusta Oluchi Mmuoegbulam ◽  
Augustine Agorye Unimke ◽  
Iniobong Ebenge Andy ◽  
Ogemdi Chinwendu Anika ◽  
Rachael Teniola Macaulay
Keyword(s):  
Plate Count ◽  
Heterotrophic Plate Count ◽  
Sachet Water

Other heterotrophic plate count bacteria

2004 ◽  
pp. 125-143
Author(s):  
Steven Percival ◽  
Rachel Chalmers ◽  
Martha Embrey ◽  
Paul Hunter ◽  
Jane Sellwood ◽  
...  
Keyword(s):  
Plate Count ◽  
Heterotrophic Plate Count

Analysis of Bottled Water for Escherichia coli and Total Coliforms

1998 ◽  
Vol 61 (3) ◽  
pp. 334-338 ◽  
Author(s):  
M. A. GRANT
Keyword(s):  
Escherichia Coli ◽  
Simultaneous Detection ◽  
Microbiological Quality ◽  
Bottled Water ◽  
Plate Count ◽  
Heterotrophic Plate Count ◽  
Positive Error ◽  
False Positive Error ◽  
Total Coliforms ◽  
Quality Guidelines

U.S. Food and Drug Administration regulations governing bottled water include microbiological quality guidelines based on coliform counts. Recently, a new MF medium for simultaneous detection of total coliforms and Escherichia coli was developed. This medium, m-ColiBlue24 (m-CB) was compared to m-Endo medium and an International Organization for Standardization standard coliform medium, lactose agar with Tergitol 7. Coliform analysis was conducted on 104 brands of bottled water from 10 countries. Some samples were additionally analyzed for heterotrophic plate count and Pseudomonas sp. populations, including P. aeruginosa. Presumptive coliform colonies were found in 5.8% of the samples with m-CB, 1.9% with m-Endo and 11.5% with lactose agar with Tergitol 7. None of the presumptive coliforms from any of the three media were verified as true coliforms in subsequent analysis. Consequently, the presumptive recovery rates actually represented false-positive error (FPE) rates. The FPE for m-CB and m-Endo were not statistically different (P < 0.05) but the FPE for lactose agar with Tergitol 7 was significantly larger.

scholarly journals Mobile Dental Delivery System: An Effective Protocol for Hygiene and Disinfection

2020 ◽  
Vol 17 (5) ◽  
pp. 1603 ◽  
Author(s):  
Damien Offner ◽  
Gabriel Fernandez De Grado ◽  
Marion Strub ◽  
Laure Belotti ◽  
Stéphanie Deboscker ◽  
...  
Keyword(s):  
Dental Care ◽  
Care Delivery ◽  
Microbiological Quality ◽  
Plate Count ◽  
Heterotrophic Plate Count ◽  
Dental Procedures ◽  
Dental Care Delivery ◽  
Dental Unit Waterlines ◽  
Over Time

Mobile dental delivery systems (MDDSs) are receiving growing interest for reaching isolated patients, as well as in dental care for fragile and hospitalized patients, with the advantage of being able to be used from room to room or during general anesthesia (GA) in an operating room. Therefore, ensuring the care safety is crucial. The aim of this study was to elaborate and assess an MDDS maintenance protocol, containing the management of dental unit waterlines and adapted to specific conditions such as dental care under GA. A step-by-step protocol was established and implemented for an MDDS used during dental care under GA in children. Samples of the output water were collected at J0, J+1, 3, 6, 12, and 24 months, and cultured to observe the microbiological quality of the water. All the results (heterotrophic plate count at 22 °C, at 37 °C, and specific pathogenic germs sought) showed an absence of contamination. The protocol presented was effective over time and allowed ensuring the safety of care to be ensured when using MDDS, even during dental procedures under GA. As a result, it could be implemented by any dental care delivery structure wanting to reinforce the safety of its practice.

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.

Membrane filtration for particles removal after ozonation-biofiltration

2007 ◽  
Vol 56 (10) ◽  
pp. 101-108 ◽  
Author(s):  
S. Osterhus ◽  
K. Azrague ◽  
T. Leiknes ◽  
H. Odegaard
Keyword(s):  
Membrane Reactor ◽  
Membrane Filtration ◽  
Submicron Particles ◽  
Plate Count ◽  
Uv Absorbance ◽  
Heterotrophic Plate Count ◽  
Operational Factors ◽  
Process Combination ◽  
By Products ◽  
Very High

With the process combination Ozonation-Biofiltration-Membranefiltration (the OBM-process) an average removal of 63% for UV-absorbance (UV254), 79% for color, and 28% for DOC was obtained treating NOM containing surface water. In this paper, focus has been made on the removal of particles after the ozonation and biofiltration treatment steps, using a submerged hollow fiber ultrafiltration membrane reactor. For this purpose the membrane performed adequately. The ultrafiltration step did not have a significant impact on the removal of color, UV254, and DOC. However, the SS and the heterotrophic plate count (HPC) was almost completely removed, and the turbidity was reduced by 65% by the membrane filtration, even at very high fluxes. Fouling occurred during operation, and operational factors of both the ozonation/biofiltration and the membrane reactor were important for controlling this. The experiments at pH 6.5 gave a higher permanent fouling than at pH 8.5, which was caused by the different oxidation pathways and consequently by the change in size and hydrophobicity of the by-products. On the other hand, the reversible fouling was less important at low pH. The mechanical cleaning was efficient, however, it seemed that the air scouring participated to the formation of submicron particles which favored the fouling.

scholarly journals Multiregional Evaluation of the SimPlate Heterotrophic Plate Count Method Compared to the Standard Plate Count Agar Pour Plate Method in Water

2000 ◽  
Vol 66 (1) ◽  
pp. 453-454 ◽  
Author(s):  
R. Wayne Jackson ◽  
Karen Osborne ◽  
Gary Barnes ◽  
Carol Jolliff ◽  
Dianna Zamani ◽  
...  
Keyword(s):  
Regression Analysis ◽  
Water Samples ◽  
Plate Count ◽  
Heterotrophic Plate Count ◽  
Plate Method ◽  
Standard Plate Count ◽  
Plate Count Agar ◽  
Count Method ◽  
Standard Plate ◽  
Plate Count Method

ABSTRACT A new SimPlate heterotrophic plate count (HPC) method (IDEXX Laboratories, Westbrook, Maine) was compared with the pour plate method at 35°C for 48 h. Six laboratories tested a total of 632 water samples. The SimPlate HPC method was found to be equivalent to the pour plate method by regression analysis (r = 0.95;y = 0.99X + 0.06).

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