scholarly journals Factors influencing detection and enumeration of Pseudomonas aeruginosa by most-probable-number and membrane filtration techniques.

1975 ◽  
Vol 30 (6) ◽  
pp. 935-942 ◽  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Membrane Filtration ◽  
Most Probable Number ◽  
Probable Number ◽  
Factors Influencing

Comparative study of membrane filtration and enrichment media for the isolation and enumeration of Pseudomonas aeruginosa from sewage, surface water, and swimming pools

1985 ◽  
Vol 31 (8) ◽  
pp. 686-692 ◽  
Author(s):  
A. H. Havelaar ◽  
M. During ◽  
E. H. M. Delfgou-Van Asch
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Membrane Filtration ◽  
Culture Media ◽  
Polluted Water ◽  
Most Probable Number ◽  
Cellulose Ester ◽  
Swimming Pools ◽  
Probable Number ◽  
Membrane Filters ◽  
Swimming Water

The recovery of Pseudomonas aeruginosa on several selective culture media was tested using raw sewage and secondary sewage effluent samples as well as spiked chlorinated imitation swimming water and samples from whirlpools. mPA-medium B gave good recovery of both vital and chlorine-injured P. aeruginosa and selectivity was greater than 90% when analysing whirlpool samples. It is therefore the medium recommended for examination of chlorinated swimming pools. When analysing sewage polluted water with the mPA-B medium, reduced selectivity was noted from low verification rates and from overgrowth by competitive flora. A modified medium (mPA-D; addition of cetrimide, omission of sulphapyridine and actidione) was more selective and sufficiently recovered noninjured cells. Chlorine-injured cells were completely inhibited, however. C-390 (9-chloro-9-(4-diethylaminophenyl)-10-phenylacridan) was confirmed to be highly selective for P. aeruginosa when used in spread plates at a concentration of 30 μg/mL; P. aeruginosa was slightly inhibited. However, the medium could not be used with conventional membrane filtration techniques, because cellulose ester filters interfered with the selective action of C-390. Selectivity could be improved by using Gelman Tuffryn (polysulphone) filters and increasing the C-390 concentration to 120 μg/mL. At this concentration, however, the medium was strongly inhibitory to P. aeruginosa; resuscitation only partially improved recovery. Two other membrane filtration media were tested. Both cetrimide – nalidixic acid agar and Drake's medium No. 19 were inhibitory to chlorine-injured cells. Several types of membrane filters were tested and there was little difference between them. In the most-probable-number technique, recovery of P. aeruginosa was shown to be excellent when using asparagine broth. Malachite green broth was strongly inhibitory to chlorine-injured P. aeruginosa.

scholarly journals Evaluation of an MPN test for the rapid enumeration of Pseudomonas aeruginosa in hospital waters

2014 ◽  
Vol 13 (2) ◽  
pp. 427-436 ◽  
Author(s):  
David P. Sartory ◽  
Danièle Pauly ◽  
Nathalie Garrec ◽  
Lucia Bonadonna ◽  
Maurizio Semproni ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Membrane Filtration ◽  
Most Probable Number ◽  
Insufficient Data ◽  
Culture Methods ◽  
Probable Number ◽  
Rapid Enumeration ◽  
Relative Differences ◽  
Mpn Test ◽  
Atypical Strains

In this study, the performance of a new most probable number (MPN) test (Pseudalert®/Quanti-Tray®) for the enumeration of Pseudomonas aeruginosa from hospital waters was compared with both international and national membrane filtration-based culture methods for P. aeruginosa: ISO 16266:2006 and UK The Microbiology of Drinking Water – Part 8 (MoDW Part 8), which both use Pseudomonas CN agar. The comparison based on the calculation of mean relative differences between the two methods was conducted according to ISO 17994:2014. Using both routine hospital water samples (80 from six laboratories) and artificially contaminated samples (192 from five laboratories), paired counts from each sample and the enumeration method were analysed. For routine samples, there were insufficient data for a conclusive assessment, but the data do indicate at least equivalent performance of Pseudalert®/Quanti-Tray®. For the artificially contaminated samples, the data revealed higher counts of P. aeruginosa being recorded by Pseudalert®/Quanti-Tray®. The Pseudalert®/Quanti-Tray® method does not require confirmation testing for atypical strains of P. aeruginosa, saving up to 6 days of additional analysis, and has the added advantage of providing confirmed counts within 24–28 hours incubation compared to 40–48 hours or longer for the ISO 16266 and MoDW Part 8 methods.

A Most Probable Number Method for the Enumeration of Legionella Bacteria in Water

1991 ◽  
Vol 24 (2) ◽  
pp. 143-147 ◽  
Author(s):  
N. A. Grabow ◽  
R. Kfir ◽  
W. O. K. Grabow
Keyword(s):  
Water Samples ◽  
Membrane Filtration ◽  
Quantitative Method ◽  
Fluorescent Antibody ◽  
Most Probable Number ◽  
Probable Number ◽  
Comparative Tests ◽  
Antibody Staining ◽  
Direct Fluorescent Antibody ◽  
Yeast Extract Agar

A new quantitative method for the enumeration of Legionella bacteria in water is described. Appropriate tenfold serial dilutions of water samples concentrated by membrane filtration are plated in triplicate on buffered charcoal yeast extract agar. After incubation for 3 days representative smears from individual plates are tested for the presence of Legionella by direct fluorescent antibody staining. The number of positive plates in each dilution is used to calculate the Legionella count by means of conventional most probable number statistics. In comparative tests on a variety of water samples this method yielded significantly higher counts than previously used procedures.

The relationship between three potential pathogens and pollution indicator organisms in Nova Scotian coastal waters

1983 ◽  
Vol 29 (10) ◽  
pp. 1261-1269 ◽  
Author(s):  
W. J. Robertson ◽  
R. S. Tobin
Keyword(s):  
Membrane Filtration ◽  
Indicator Bacteria ◽  
Fecal Coliforms ◽  
Most Probable Number ◽  
Indicator Organisms ◽  
Fecal Indicator ◽  
Filtration Method ◽  
Probable Number ◽  
Pollution Indicator ◽  
Nova Scotian

Fifteen stations, in two estuaries, along the Northumberland Strait of Nova Scotia were examined between June and September 1981 for a relationship between the concentrations of commonly monitored fecal indicator bacteria and the potential pathogens Candida albicans, Pseudomonas aeruginosa, and Vibrio parahaemolyticus. Increased densities of these three organisms were usually associated with high densities of indicator bacteria. Whereas C. albicans and P. aeruginosa occur in human fecal wastes, V. parahaemolyticus is indigenous to the marine environment and positively responds to elevated nutrient levels in sewage. There is also some evidence that these bacteria survive as long or longer in marine waters than the common indicator bacteria. While membrane-filtration techniques for the enumeration of C. albicans and P. aeruginosa proved satisfactory, a V. parahaemolyticus membrane-filtration method lacked specificity and was supplemented by a most-probable-number method. In marine recreational and shellfish waters, these three organisms could complement fecal coliforms and fecal streptococci as indicators of human fecal contamination.

scholarly journals Rapid single-tube confirmatory test forEscherichia coli

1982 ◽  
Vol 89 (1) ◽  
pp. 149-154 ◽  
Author(s):  
J. L. Smith ◽  
S. Rockliff
Keyword(s):  
Membrane Filtration ◽  
Confirmatory Test ◽  
Most Probable Number ◽  
Standing Committee ◽  
Traditional Methods ◽  
Probable Number ◽  
Single Tube ◽  
Laboratory Service ◽  
The Public ◽  
E Coli

SUMMARYA single-tube confirmatory test that allows a result to be obtained in 4 h has been developed from the single-tube confirmatory test recommended by the Joint Committee of the Public Health Laboratory Service and the Standing Committee of Analysts (PHLS/SCA, 1980). A variety of river, lake and reservoir samples were examined for the presence ofE. coliusing either most probable number (MPN) or membrane filtration (MF) technique, and the PHLS/SCA recommended confirmatory medium (LTMB) was evaluated against traditional methods. To improve the performance of LTMB, the medium was modified and this modified medium when used in 0·1 ml volumes and incubated for 4 h at 44°C provided 99% agreement with traditional methods.

scholarly journals Correlation between Quantitative PCR and Culture-Based Methods for Measuring Enterococcus spp. over Various Temporal Scales at Three California Marine Beaches

2011 ◽  
Vol 78 (4) ◽  
pp. 1237-1242 ◽  
Author(s):  
Reagan R. Converse ◽  
John F. Griffith ◽  
Rachel T. Noble ◽  
Richard A. Haugland ◽  
Kenneth C. Schiff ◽  
...  
Keyword(s):  
Quantitative Pcr ◽  
Membrane Filtration ◽  
Empirical Relationship ◽  
Time Of Day ◽  
Most Probable Number ◽  
Spatial And Temporal Variability ◽  
Culture Methods ◽  
Fecal Indicator ◽  
Probable Number ◽  
Content Type

ABSTRACTSeveral studies have examined how fecal indicator bacteria (FIB) measurements compare between quantitative PCR (qPCR) and the culture methods it is intended to replace. Here, we extend those studies by examining the stability of that relationship within a beach, as affected by time of day and seasonal variations in source.Enterococcusspp. were quantified at three southern California beaches in the morning and afternoon using two qPCR assays, membrane filtration, and defined-substrate testing. While qPCR and culture-based measurements were consistently and significantly correlated, strength of the correlation varied both among and within beaches. Correlations were higher in the morning (0.45 < ρ < 0.74 [P< 0.002]) than in the afternoon (0.18 < ρ < 0.45 [P< 0.021]) and higher when the fecal contamination was concentrated (0.38 < ρ < 0.83 [P< 0.001]) than when it was diffuse (0.19 < ρ < 0.34 [P< 0.003]). The ratios of culture-based and qPCR results (CFU or most probable number [MPN] per calibrator cell equivalents [CCE]) also varied spatially and temporally. Ratios ranged between 0.04 and 0.85 CFU or MPN per CCE and were lowest at the beach affected by diffuse pollution. Patterns in the ratios over the course of the day were dissimilar across beaches, increasing with time at one beach and decreasing at another. The spatial and temporal variability we observed indicate that the empirical relationship between culture-based and qPCR results is not universal, even within a beach.

scholarly journals The efficiency of a low-cost hydrogen sulphide (H2S) kit as an early warning test for assessing microbial rainwater quality and its correlation with standard indicators microorganisms

2019 ◽  
Vol 18 (2) ◽  
pp. 133-143
Author(s):  
Mokaba Shirley Malema ◽  
Jean-Marc Mwenge Kahinda ◽  
Akebe Luther King Abia ◽  
Roman Tandlich ◽  
Bongumusa M. Zuma ◽  
...  
Keyword(s):  
South Africa ◽  
Membrane Filtration ◽  
Low Cost ◽  
Most Probable Number ◽  
Eastern Cape ◽  
Local Conditions ◽  
Probable Number ◽  
Faecal Contamination ◽  
Test Kit ◽  
Number Of Cells

Abstract Testing microbial quality of the harvested rainwater remains a challenge in many countries. The H2S test kit is a low-cost microbiological field-based test which can be used in areas where water testing facilities are limited. This study compares its efficiency with the standard indicators microorganisms in the detection of faecal contamination of rainwater in South Africa. A total of 88 rainwater samples were collected from various tanks in the Eastern Cape, South Africa over three months in 2016. The collected samples were analysed for faecal bacterial contamination using the H2S test kit, Colilert-18/Quanti-tray®/2000 and the membrane filtration technique for faecal coliforms (MFT). The correspondence rate of the H2S test kit with MFT was 88 %, while for the Colilert® it was 76 %. The H2S test kit confirmed faecal contamination when concentrations of standards indicators microorganisms were 5 most-probable number of cells/100 cm3 or higher. Overall, the best correspondence of the H2S test kit with Colilert® was observed at E. coli concentrations above 50 most-probable number of cells/100 cm3. Results of the H2S test kit correlated better with MTF, while the medium used has strongly influenced the enumeration of faecal contamination. Results point to strong effect of media used and revealed the need to calibrate the correspondence between the standard indicator microorganisms and the H2S test kit under local conditions for specific settings.

scholarly journals Antibiotic Susceptibility of Bacteria Isolated from Abattoir Effluent-Impacted Tagangu River, Aliero, Kebbi State, North-Western Nigeria

2019 ◽  
pp. 1-8 ◽  
Author(s):  
B. G. Jega ◽  
O. O. Adebisi ◽  
S. S. Manga
Keyword(s):  
Escherichia Coli ◽  
Pseudomonas Aeruginosa ◽  
Antibiotic Susceptibility ◽  
Microbiological Quality ◽  
Most Probable Number ◽  
Resistant Bacteria ◽  
Proteus Vulgaris ◽  
Probable Number ◽  
Antibiotic Susceptibility Test ◽  
The Impact

This study aimed to evaluate the impact of abattoir effluent on microbiological quality of the receiving Tagangu River and the susceptibility of the isolates to commonly-used antibiotics. The most probable number (MPN) as well as the Kirby-Bauer method of antibiotic susceptibility test were used and demonstrated the total heterotrophic bacteria as well as Escherichia coli O157:H7 numbers in a total of 30 water samples collected over a period of three months at three strategic points of the river. In accordance with CLSI guidelines, four out of eight bacteria (Enterobacter sp., Pseudomonas aeruginosa, Proteus vulgaris and Citrobacter sp.) isolated, demonstrated multiple antibiotic resistance (MAR) against at least three out of septrin, chloramphenicol, amoxicillin, augmentin, gentamicin, tarivid and streptomycin. All the isolates (Escherichia coli, Klebsiella pneumoniae, Enterobacter sp., Pseudomonas aeruginosa, Proteus vulgaris, Citrobacter sp., Serratia marcescens and Aerobacter aerogenes) showed either high or intermediate susceptibility to sparfloxacin, ciprofloxacin and pefloxacin. The findings indicated that the river has been heavily polluted with the effluent discharges and did not meet any of the WHO guidelines for natural water sources fit for irrigation or other domestic purposes. As such, indiscriminate discharge of abattoir effluent could impact on the microbiological quality and promote increased incidence of multiple antibiotic resistant bacteria in a receiving river.

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