scholarly journals Comparison of the Pseudalert™/Quanti‐Tray ® MPN test for the enumeration of Pseudomonas aeruginosa in cooling tower water with the ISO 16266 membrane filtration culture‐based method

2020 ◽  
Vol 128 (6) ◽  
pp. 1843-1850
Author(s):  
K. Spies ◽  
S. Pleischl ◽  
D. Sartory
2014 ◽  
Vol 13 (2) ◽  
pp. 427-436 ◽  
Author(s):  
David P. Sartory ◽  
Danièle Pauly ◽  
Nathalie Garrec ◽  
Lucia Bonadonna ◽  
Maurizio Semproni ◽  
...  

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.


1985 ◽  
Vol 31 (8) ◽  
pp. 686-692 ◽  
Author(s):  
A. H. Havelaar ◽  
M. During ◽  
E. H. M. Delfgou-Van Asch

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.


2003 ◽  
Vol 48 ◽  
pp. 39-46
Author(s):  
Dragi Todorovic ◽  
Ana Sokolovska ◽  
Hristina Babunovska

A validation of the method for determination of the microbiological purity of Caffetin® tablets has been done. For this purpose the test microorganisms: Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Candida albicans and Aspergillus niger from the collection ATCC have been used. A non-specific nutritious medium for aerobic microorganisms and specific nutritious media for adequate test microorganisms: ENDO, Cetrimid, Baird-Parker and Sabouraud nutritious agar medium have been used. The method was performed in two modes: a direct inoculation into a nutritious medium and a membrane filtration. At the same time, a Challenge test was as well used the test of counting the growing colonies (CFU/ml). A calculation of the factor has been done, which represents relationship between growing microorganisms of the inoculated nutritious medium with and without adding to the examined preparation, as a criterion for acceptance of the achieved analytical results. The achieved values for the factor as a criterion for acceptance have shown satisfying values. It can be concluded that this method can be used for determination of the microbiological purity of Caffetin® tablets.


2015 ◽  
Vol 71 (6) ◽  
pp. 699-705 ◽  
Author(s):  
David P. Sartory ◽  
Megan Brewer ◽  
Agnieszka Beswick ◽  
Darron Steggles

2008 ◽  
Vol 30 (70/72) ◽  
Author(s):  
Mônica Paul Freitas ◽  
Marita Maciel Moreira Laskowski ◽  
Carlos Roberto Dalke ◽  
Patricia do Rocio Dalzoto ◽  
Ida Chapaval Pimentel

An unknown parcel of the planet water is contaminated by chemical and/or biological agents. Human and other animals excreta have been associated to many infectious diseases that can be disseminated through contaminated water. Enteric bacteria and other pathogens can cause gastroenteritis, cholera, systemic infections, among others. Once in the environment, these microorganisms can persist for large periods of time and under certain conditions can even replicate, increasing their number. This paper aimed the research and evaluation of survival rates for total coliforms, fecal coliforms (Escherichia coli) and Pseudomonas aeruginosa in natura water samples from Passaúna and Iraí barrages and Iguaçú River, in Curitiba, Paraná. Colimetric analysis of water samples were performed by the membrane filtration method 64 Freitas MP, Blaskowski MMM, Dalke CR, Dalzoto PR, Pimentel IC. Estud and P. aeruginosa research was assayed using the multiple tubes method in Asparagin and Acetamyde Broth. Confirmatory tests such as catalase presence, citocrome oxidase test and pigment P (pyocyanin) production were also performed. It was observed the occurrence of total coliforms in water samples from Iguaçú River for approximately 50 days, while in Iraí and Passaúna barrages, the periods were 35 and 14 days, respectively. Fecal coliforms were found for about 35 days in samples from Iguaçú River and Iraí barrage, while in Passaúna barrage only for 14 days. P. aeruginosa persisted for approximately 63 days in all the water samples assayed. The higher persistence rate observed in P. aeruginosa can be related to an antagonism towards total and fecal coliforms, which had their populations decreased.


1997 ◽  
Vol 43 (5) ◽  
pp. 461-466 ◽  
Author(s):  
X. Yin ◽  
L. R. Zeph ◽  
G. Stotzky

A plaque technique that uses antibiotic-resistant bacteria growing on antibiotic-containing agar for the assay lawn resulted in significantly better recovery of bacteriophages P1 of Escherichia coli and F116 of Pseudomonas aeruginosa from nonsterile soil than standard membrane filtration or centrifugation techniques. Adsorption of the phages on soil particles appeared to be involved in their recovery and survival in soil.Key words: bacteriophages, soil, antibiotic-resistant bacteria, enumeration, filtration, centrifugation.


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