scholarly journals A comparison between minerals-modified glutamate medium and lauryl tryptose lactose broth for the enumeration of Escherichia coli and coliform organisms in water by the multiple tube method

1980 ◽  
Vol 85 (1) ◽  
pp. 35-49 ◽  
Author(s):  

SummaryIn a multi-laboratory trial, minerals-modified glutamate medium (MMGM) was compared with lauryl tryptose lactose broth (LTLB) in the multiple tube method for the enumeration of coliform organisms, including Escherichia coli, in water. Samples of raw and chlorinated waters yielded a total of 2313 positive tube-reactions with MMGM and 2174 with LTLB. These were interpreted either as E. coli; other coliform organisms; or as false positive reactions. The results at first reading (18 or 24 h) and at 48 h have been analysed statistically in terms of (i) most probable numbers of coliform organisms; (ii) positive reactions and their interpretation; and (iii) whether or not the sample yielded any E. coli or other coliform organisms. All three analyses indicated the same trends. For the detection of E. coli in raw waters LTLB was better than MMGM at 18–24 h, but MMGM was better at 48 h with waters containing small numbers of coliform organisms; for raw waters with greater numbers of organisms, both media performed equally well. Analysis of a subset of samples read at both 18 and 24 h indicated that the superiority of LTLB over MMGM with raw waters disappeared by 24 h. For chlorinated waters, LTLB yielded more positive gas reactions at 18–24 h, but fewer of these were E. coli than with MMGM; at 48 h MMGM was clearly better than LTLB for total coliform organisms including E. coli – especially if the numbers were small. MMGM therefore remains the medium of choice for the detection of E. coli as an indicator of faecal contamination of chlorinated drinking water supplies. It is also better for the detection of small numbers of E. coli in other waters.

2014 ◽  
Vol 13 (2) ◽  
pp. 340-352 ◽  
Author(s):  
Andrée F. Maheux ◽  
Vanessa Dion-Dupont ◽  
Sébastien Bouchard ◽  
Marc-Antoine Bisson ◽  
Michel G. Bergeron ◽  
...  

The MI agar, Colilert®, Chromocult coliform® agar, and DC with BCIG agar chromogenic culture-based methods used to assess microbiological quality of drinking water were compared in terms of their ubiquity, sensitivity, ease of use, growth of atypical colonies and affordability. For ubiquity, 129 total coliform (representing 76 species) and 19 Escherichia coli strains were tested. Then, 635 1-L well water samples were divided into 100 mL subsamples for testing by all four methods. Test results showed that 70.5, 52.7, 36.4, and 23.3% of the non-E. coli total coliform strains and 94.7, 94.7, 89.5, and 89.5% of the 19 E. coli strains yielded a positive signal with the four methods, respectively. They also yielded a total coliform positive signal for 66.5, 51.7, 64.9, and 55.0% and an E. coli positive signal for 16.1, 14.8, 17.3, and 13.4% of the 635 well water samples tested, respectively. Results showed that Colilert® is the most expensive method tested in terms of reactants, yet it is the easiest to use. Large numbers of atypical colonies were also often observed on Chromocult coliform® and DC with BCIG, thereby challenging the target microorganism count. Thus, the MI agar method seems to be the best option for the assessment of drinking water quality.


2018 ◽  
Vol 19 (1) ◽  
pp. 128-136 ◽  
Author(s):  
S. Taonameso ◽  
L. S. Mudau ◽  
A. N. Traoré ◽  
N. Potgieter

Abstract Sporadic outbreaks of diarrhoea in children in the Vhembe rural areas could be an indication of contamination in drinking water sources. In areas where improved water sources are used, not all rural households experience the benefits of these improved water sources. Water samples were collected from boreholes in three wards in the Vhembe District to determine microbiological risks over a 5-month period. A Water Point Mapping tool was used to indicate the borehole distribution. Water samples were taken from each functional borehole and analysed for total coliform and Escherichia coli counts, electrical conductivity, pH and temperature. A multiplex PCR protocol was used for identification of pathogenic E. coli. A total of 125 boreholes were identified of which only 12 were functional. Seven boreholes tested positive for total coliforms and E. coli counts. Four boreholes (33.3%) tested positive for diarrhoeagenic E. coli. Fifty-eight percent (58%) of water samples were without health risks, 17% were low risk and 25% could cause infection according to the South African water quality standards. This study indicated the importance of the role of the Municipalities and the maintenance plans that need to ensure that all boreholes are functional and provide safe drinking water to the rural communities.


1980 ◽  
Vol 85 (2) ◽  
pp. 181-191 ◽  
Author(s):  

SUMMARYIn a multi-laboratory trial with the mombrane filtration technique, three surfactants – Teepol 610 (T610), Tergitol 7 (T7) and sodium lauryl sulphate (LS) – were compared in media for the enumeration of coliform organisms and Escherichia coli in water. A total of 170 samples of water (87 raw and 92 marginally chlorinated) were examined for colony counts of coliform organisms, and 185 water samples (94 raw and 91 marginally chlorinated) for E. coli. Slight differences in the confirmed colony counts between the three media were noted, but few of these were observed consistently in every laboratory. In most laboratories, T7 gave slightly higher counts of E. coli than LS with chlorinated waters; a higher incidence of false-positive results for E. coli at 44 °C was also noted with T7. As there were no outstanding differences in the trial, sodium lauryl sulphate, which is chemically defined, cheap and readily available, is therefore recommended for use at a concentration of 0·1% instead of Teepol 610 in the standard medium for the enumeration of coliform organisms and E. coli in water by the membrane filtration technique.


2021 ◽  
Author(s):  
Mirjana Grujović ◽  
◽  
Katarina Mladenović ◽  
Zoran Simić ◽  
Simona Đuretanović

This research aimed to investigate the quality of drinking water from the rural area of village Pajsijević (Šumadija, central Serbia). The water is consumed as raw since it is not purified or chlorinated before consumption. The water was collected at three sampling points – in the spring of Kotlenik Mountain stream (W1 sample), in the local reservoir (W2 sample), and from the tap (W3 sample). Also, the sediment samples (soil and sand) were analyzed, too. The health risks related to the presence and concentration of some major and trace elements (Ca, Cr, Cu, Fe, Mg, Mn, Ni, Zn) and N, NO, NN3, NH4, P, P2O5, and PO4 were evaluated. Additionally, the presence and the number of total coliform bacteria and Escherichia coli (as an indicator of fecal contamination) were evaluated. The concentrations of analyzed major and trace elements in all water samples were below those at which toxic effects may occur. The exception was the concentrations of Fe (2.02 – 2012 mg/L), which were higher than is allowed. The origin of Fe in water is from sediment (soil and sand), which also showed high content of Fe (3006.0 mg/g and 2229.9 mg/g, respectively). The results of the Colorimetric test indicated the presence of coliform bacteria as well as the presence of E. coli in all water samples. Further research needs to include characterization of isolated coliform bacteria and serological investigation of E. coli strains in order to evaluate the risks of consumption related to waterborne illness.


1994 ◽  
Vol 77 (1) ◽  
pp. 58-63 ◽  
Author(s):  
Philip T Feldsine ◽  
Maria T Falbo-Nelson ◽  
David L Hustead

Abstract The ColiComplete® substrate-supporting disc (SSD) method for simultaneous confirmed total coliform count and Escherichia coli determination in all foods was compared with the AOAC most probable number (MPN) methods 966.23 and 966.24. In this comparative study, 20 water and food types were analyzed; 7 of these foods were naturally contaminated with coliform bacteria, 6 food types were naturally contaminated with E. coli, and the remaining foods were inoculated with coliform bacteria and/or E. coli. Data were analyzed separately for total coliform bacteria and for E. coli. Mean log MPN counts were determined by the SSD method and the appropriate AOAC MPN procedure. Results were then analyzed for mean log MPN differences and variance, according to methods described by AOAC INTERNATIONAL Results for both total conforms and E. coli indicate that the SSD method is equivalent to or better than AOAC MPN methods 966.23 and 966.24.


2006 ◽  
Vol 4 (3) ◽  
pp. 289-296 ◽  
Author(s):  
Maggy N. B. Momba ◽  
Veronica K. Malakate ◽  
Jacques Theron

In order to study the prevalence of enteric pathogens capable of causing infection and disease in the rural communities of Nkonkobe, bacterial isolates were collected from several surface water and groundwater sources used by the community for their daily water needs. By making use of selective culture media and the 20E API kit, presumptive Escherichia coli, Salmonella spp. and Vibrio cholerae isolates were obtained and then analysed by polymerase chain reaction assays (PCR). The PCR successfully amplified from water samples a fragment of E. coli uidA gene that codes for β-D-glucuronidase which is a highly specific characteristic of enteropathogenic E. coli, enterotoxigenic E. coli and entero-invasive E. coli. The PCR also amplified the epsM gene from water samples containing toxigenic V. cholerae. Although E. coli was mostly detected in groundwater sources, toxigenic V. cholerae was detected in both surface and groundwater sources. There was a possibility of Salmonella typhimurium in Ngqele and Dyamala borehole water samples. The presence of these pathogenic bacteria in the above drinking water sources may pose a serious health risk to consumers.


2018 ◽  
Vol 46 (1) ◽  
pp. 6
Author(s):  
Carolina Maciel Malgarin ◽  
Karine Ludwig Takeuti ◽  
Anne Caroline de Lara ◽  
David Emilio Santos Neves de Barcellos

Background: One of the most frequent health problems in the swine industry is the post-weaning diarrhea in nursery pigs, which leads to significant losses due to weight loss, dehydration, cost of medication and mortality. Escherichia coli  (E. coli) is one of the main bacterial agents of the post-weaning diarrhea. To investigate the possibility of enterotoxigenic  E. coli (ETEC) transmission through drinking water to nursery piglets, the objective of this study was to isolate, characterize by virulence factors, and compare the antimicrobial resistance profiles of E. coli from drinking water samples in nurseries and from rectal swabs of their piglets presenting post-weaning colibacillosis.Materials, Methods & Results: Fifteen rectal swabs from diarrheic piglets in their first three weeks after weaning and one water sample were collected from each of ten nurseries located in Rio Grande do Sul State, south of Brazil. After enrichment with a commercial broth medium, water samples were cultured in blood agar, as well as the rectal swab samples, and the characteristic colonies were identified by standard biochemical analysis. Following isolation and identification of E. coli, the colonies from water samples and their corresponding piglets’ samples were characterized by multiplex PCR in order to determine specific ETEC fimbria and toxin genes. Finally, all E. coli isolates were submitted to antimicrobial susceptibility testing. Virulence factors and antimicrobial sensitivity could then be compared between water and piglets’ samples. The difference in the antimicrobial resistance frequency for each of the sample groups were compared using the multi comparison test. E. coli was isolated in four out of the ten water samples, although none of the water samples presented ETEC virulence factors. From 60 rectal swab samples (15 from each of the four positive farms with E. coli isolated from water samples), 21 E. coli were isolated and seven demonstrated characteristic ETEC virulence factors. The fimbriae exhibited in higher frequency were F18 (62.5%) and F4 (25%) and the toxins were STb (100%) and STaP (75%). E. coli isolated from water samples presented higher resistance to the antimicrobials apramycin, florfenicol, lincomycin, lincomycin+spectinomycin, oxytetracycline, and sulfamethoxazole+trimethoprim; it did not present resistance to colistin and fosfomycin. The seven ETEC from rectal swab samples presented a higher resistance to lincomycin, and lower resistance frequency to fosfomycin. The other 14 E. coli non-ETEC from rectal swab samples presented a higher resistance to florfenicol and no resistance to colistin.Discussion: Enterotoxigenic E. coli is an important agent causing post-weaning colibacillosis, although, differently from other studies, this experiment did not find the agent in most of the sampled animals. In contrast to other authors, ETEC was not found in water, as the development of its virulence factors may depend on conditions presented exclusively in the animal. By the results we can conclude that, although E. coli was isolated from the drinking water, it was not a significant mechanism for nursery piglets’ infection with ETEC in this experiment. The samples analyzed presented a wide range of resistance to different antimicrobials, including multi-resistance. In some cases, E. coli found in water presented different antimicrobial profile from the bacterium found in the rectal swab samples. Enterotoxigenic E. coli was susceptible to fosfomycin and its use may represent a prudent antimicrobial choice to the swine industry.


2015 ◽  
Vol 9 (4) ◽  
pp. 300
Author(s):  
Rolan Sudirman Pakpahan ◽  
Intje Picauly ◽  
I Nyoman W. Mahayasa

AbstrakJumlah layanan air minum melalui depot air minum di Kota Kupangmeningkat dengan rata-rata 1,44 setiap tahun sejak 2010, sementara tidakterdapat jaminan kualitas air minum isi ulang memenuhi syarat setiap saat. Hasil pemeriksaan sampel air minum isi ulang di Kota Kupang tahun 2013 menunjukkan 37,5% tercemar mikroba. Tujuan penelitian ini adalah menganalisis cemaran mikroba dan mengetahui determinan cemaran Escherichia coli (E. coli) dan total koliform pada air minum isi ulang. Penelitian ini menggunakan desain studi potong lintang periode Januari Maret 2015. Populasi penelitian berjumlah 51 depot air minum yang ditentukan menggunakan teknik total sampling. Analisis data dilakukan secara univariat, analisis bivariat menggunakan uji regresi logistik sederhana, dan analisis multivariat menggunakan regresi logistik berganda. Hasil penelitian terhadap 51 depot air minum menunjukkan air minum telah tercemar mikroba sebanyak 26 depot air minum (51%), tercemar E. coli 33,33%, dan tercemar total koliform 51%. Deteminan cemaran mikroba dengan uji bivariat adalah pengetahuan (nilai p = 0,01), sikap operator (nilai p = 0,05). Sedangkan determinan cemaran mikroba uji multivariat adalah pengetahuan operator (nilai p = 0,026), kebersihan operator (nilai p = 0,05) dan sanitasi depot air minum (nilai p = 0,044). Variabel yang paling dominan memengaruhi cemaran mikroba adalah pengetahuan, kebersihan operator, dan sanitasi depot air minum.AbstractAmount of drinking water services through drinking water depots in KupangCity is increasing in avarage of 1.44 every year since 2010, meanwhilethere is no guarantee that refill drinking water quality meets any requirement every time. Results of refill drinking water sample in Kupang City in 2013 showed the water was 37.5% contaminated by microbes. This study aimed to analyze microbial contamination and determine determinants of Escherichia coli (E. coli) and total Coliform on refill drinking water. This study used cross sectional design on January - March 2015. The population was 51 depots determined using total sampling technique. Data analysis was conducted in univariate, bivariate using simple logistic regression test and multivariate using multiple logistic regression test. Results showed drinking water contaminated by microbes worth 26 depots (51%), by E. coli 33.33% and by total Coliform 51%. Microbial contamination determinants using bivariate were knowledge (p value = 0.01) and behavior of operator (p value = 0.05). Meanwhile, microbial contamination determinants conducting multivariate were knowledge (p value = 0.026), hygiene of operator (p value = 0.05) and depot sanitation (p value = 0.044). Most dominating variables influencing microbial contamination are knowledge, operator’s hygiene and depot sanitation.


Jurnal BIOMA ◽  
2017 ◽  
Vol 11 (1) ◽  
pp. 73
Author(s):  
Rezki Rachmawati ◽  
Muzajjanah Muzajjanah ◽  
Yoswita Rustam

Refill Water Depot is currently more widely circulated and used as an alternative drinking water supply by the public. However the still unclear about the quality of the drinking water refill generated primarily of biological content. Parameters of biological contamination in drinking water caused by the Escherichia coli and coliform bacterium. This study aims to identify E. coli and coliforms in drinking water refill. Refill drinking water samples obtained from 16 drinking water refill from Jagakarsa subdsitrict. The method used is descriptive. Refill drinking water samples was taken and tested in the MPN (Most Probable Number) method and then to be tested in identification of E. coli. The results of testing the drinking water refill obtained 15 samples positive for coliform bacteria. Samples were positive for E. coli bacteria that sample B.1 and F.2.


2020 ◽  
Vol 20 (3) ◽  
pp. 1083-1090
Author(s):  
M. Wolf-Baca ◽  
A. Siedlecka

Abstract Drinking water should be free from bacterial pathogens that threaten human health. The most recognised waterborne opportunistic pathogens, dwelling in tap water, are Legionella pneumophila and Escherichia coli. Drinking water samples were tested for the presence of Legionella spp., L. pneumophila, and E. coli in overall sample microbiomes using a quantitative real-time polymerase chain reaction (qPCR) approach. The results indicate a rather low contribution of Legionella spp. in total bacteria in the tested samples, but L. pneumophila was not detected in any sample. E. coli was detected in only one sample, but at a very low level. The qacEΔ1 gene, conferring resistance to quaternary ammonium compounds, was also not detected in any sample. The results point to generally sufficient quality of drinking water, although the presence of Legionella spp. in tap water samples suggests proliferation of these bacteria in heating units, causing a potential threat to consumer health.


Sign in / Sign up

Export Citation Format

Share Document