scholarly journals Assessment of microbial contamination of drinking water with total coliform bacteria and Escherichia coli in the Bitola region

2019 ◽  
Vol 65 (2) ◽  
pp. 23-32
Author(s):  
Marta Nedelkova ◽  
Angela Delova ◽  
Tanja Petreska Ivanovska ◽  
Zoran Zhivikj ◽  
Lidija Petrushevska-Tozi

The aim of this paper is to analyze the presence of Escherichia coli (E. coli) and total coliform bacteria (CB) in the drinking water of urban and rural areas of the Bitola region, as indicators for water quality and safety. All water in urban area is chlorinated, while at the same time the water in rural areas is non-chlorinated. The samples were analyzed according to the international standard method of membrane filtration MKC EN ISO 9308-1:2015. In all examined samples of drinking water in urban area, presence of E. coli and CB was not detected as a result of the disinfection of the water. On contrary, in all tested samples of the water from the rural water supply, presence of E. coli and CB was confirmed. Significant increase in coliform bacterial counts probably weather-related was found in the period from April to September. In addition, in the third quarter including July, August, and September, in many measurements, E. coli as an indicator of faecal contamination was identified in drinking water. In accordance with these findings and in order to provide safe drinking water, it is necessary to modernize the water supply for the population in rural areas, to disinfect permanently the drinking water and to apply regular laboratory controls which are a basic pre-condition. Otherwise, inappropriate management of the water systems can cause serious decrease in the quality and safety of the drinking water associated with an increased risk of appearance of the infectious diseases in people and hydric epidemic. Key words: drinking water, Escherichia coli, coliform bacteria, membrane filtration

2020 ◽  
Vol 10 (2) ◽  
pp. 298-308
Author(s):  
Carlos I. Gonzalez ◽  
John Erickson ◽  
Karina A. Chavarría ◽  
Kara L. Nelson ◽  
Amador Goodridge

Abstract Safe water storage is critical to preserve water quality, especially when intermittent piped drinking water supply creates a need for household storage. This study characterized household storage practices and stored water quality in 94 households (N = 94) among four peri-urban neighborhoods in Arraiján, Panama with varying degrees of supply intermittency. We found that 18 (19.1%) households stored drinking water in unsafe containers. Forty-four (47%) samples of household stored drinking water had residual chlorine levels <0.2 mg/L. While 33 (35.1%) samples were positive for total coliform bacteria, only 23 (24.4%) had >10 most probable number (MPN)/100 mL total coliform bacteria. Eight (44%) samples were positive for Escherichia coli, whereas only one (1.3%) sample from the safe containers was positive. Twenty-nine (30.9%) samples had >500 MPN/mL heterotrophic plate count bacteria. These findings suggest that longer supply interruptions were associated with longer storage times and lower chlorine residual, which were associated with higher concentrations of indicator bacteria. This is one of the first studies in the Central-American region to show an association between the lack of turnover (replacement with fresh water) and greater contamination during household water storage. Thus, when drinking water supply is not completely continuous and household storage is required, decreasing the time between supply periods can facilitate safer water storage. Public awareness and education are also recommended to increase hygiene practices during water collection and storage.


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.


2013 ◽  
Vol 76 (7) ◽  
pp. 1152-1160 ◽  
Author(s):  
SONIA MAGAÑA ◽  
SARAH M. SCHLEMMER ◽  
STEPHANEY D. LESKINEN ◽  
ELIZABETH A. KEARNS ◽  
DANIEL V. LIM

An automated concentration system (ACS) based on dead-end ultrafiltration was used in this study to concentrate bacteria, including Escherichia coli O157:H7, from 50-liter produce washes (PWs, sieved produce wash). Cells trapped in the filters were recovered in approximately 400 ml of buffer to create PW retentates (PWRs). Extent of concentration was determined by analyzing PWs and PWRs for total coliform bacteria and E. coli O157:H7 using standard methods. In addition, an electrochemiluminescence immunoassay was evaluated for detection of E. coli O157:H7 in spiked PWs and PWRs to demonstrate usefulness of the ACS for same-day detection. The levels of total coliform bacteria and E. coli O157:H7 in PWRs were higher than those in PWs by 1.85± 0.41 log most probable number per 100 ml and 1.82 ± 0.24 log CFU/ml, respectively. Electrochemiluminescence detection of E. coli O157:H7 was accomplished within 2 h using ACS concentration of lettuce and spinach wash water artificially spiked with the pathogen at levels as low as 0.36 log CFU/ml and 1.39 log CFU/ml, respectively. Detection of E. coli O157:H7 at −0.93 ± 0.15 log CFU/ml in lettuce wash occurred within approximately 6 h when a 4-h enrichment step was added to the procedure. Use of dead-end ultrafiltration increased bacterial concentrations in PWR and allowed same-day detection of low levels of E. coli O157:H7 in PW. This concentration system could be useful to improve the sensitivity of current rapid methods for detection of low levels of foodborne pathogens in PW water.


1996 ◽  
Vol 13 (2) ◽  
pp. 63-67
Author(s):  
Hiroshi NAKAYAMA ◽  
Kazumi HORIKAWA ◽  
Takeshi USHIO ◽  
Tastuoki MASTUNAGA ◽  
Masatoshi YAIRI ◽  
...  

Water ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 670 ◽  
Author(s):  
Shatha Alazzeh ◽  
Stephanie Galaitsi ◽  
Amahl Bishara ◽  
Nidal Al-Azraq ◽  
John L. Durant

We investigated the quality of treated drinking water in Aida Camp and Alazzah Camp, two Palestinian refugee camps in the West Bank. Water supply in the two camps is intermittent: Water deliveries are first stored in a centrally located community tank before being pumped through distribution networks to users, who then store the water in rooftop tanks. Between March 2016 and June 2017, we examined water quality within the distribution system in the camps, testing 520 samples in Aida Camp and 198 samples in Alazzah Camp for total coliforms, Escherichia coli (E. coli) bacteria, and residual chlorine. We observed deterioration in water quality in both camps, but the deterioration was more pronounced in Aida Camp where 2.5% of community-tank samples, 5.0% of network samples, and 10% of rooftop-tank samples contained one or more colonies (per 100 mL) of total coliform bacteria. In Alazzah Camp, 3.7% of community-tank samples, 2.5% of network samples, and 5% rooftop-tank samples contained one or more colonies (per 100 mL) of total coliform bacteria. E. coli was detected in two samples from Aida Camp and one sample from Alazzah Camp. In both camps, average residual chlorine concentrations were higher in the community tanks than in rooftop tanks. The main factor influencing water quality deterioration in rooftop tanks in Aida Camp appears to be air temperature. We recommend more systematic water testing in the camps and greater transparency in reporting test results to camp residents.


1972 ◽  
Vol 35 (2) ◽  
pp. 67-70
Author(s):  
Jose de A. Moura Fé ◽  
F. Eugene Nelson

Estimates of populations of “total” coliform bacteria in raw mi1k were quantitatively essentially the same when Violet Red Bile agar incubated at 32 C and Lauryl Sulfate Tryptose Broth incubated at 37 C were used. Qualitatively, LST tended to favor recovery of a greater proportion of Aerobaoter aerogenes and IMViC-irregular types. Of the 46 isolates that produced ropiness, 35 were recovered from LST. Escherichia coli populations, as determined on EC medium incubated at 44.5 C, showed no constant relationship to total coliform population. Summer samples contained not only greater numbers of E. coli but also these organisms constituted a greater proportion of the coliform population.


2019 ◽  
Vol 2 (2) ◽  
pp. a13-19
Author(s):  
ELEXSON NILLIAN ◽  
AMIZA NUR ◽  
DIYANA NUR ◽  
AMIRAH ZAKIRAH ◽  
GRACE BEBEY

Contamination of drinks with E. coli O157:H7 served in food premises such as restaurants can cause haemorrhagic colitis and haemolytic uremic syndrome to humans. The presence or absence of faecal pathogen was demonstrated using coliform group as indicator microorganisms. Therefore, this study was conducted to detect the presence of E. coli O157:H7 in drinking water from food restaurant premise in Kota Samarahan and Kuching to ensure safe and potable drinking water is served to the consumer. A total of thirty (n=30) drink samples including six types of each of the samples are cold plain water, iced tea, iced milo, syrup and iced milk tea. Most Probable Number (MPN) procedure was used in this study to enumerate the MPN values of coliform bacteria in each drink collected. A total of 53.33% (16/30) of the drink samples showed positive E. coli detection. Then, the PCR assay showed 6.25% (one out of 16 isolates) samples were positive and carried stx1 gene produced by E. coli O157:H7 in iced milo sample types. This study showed the drinks collected from food premises was contaminated with faecal contamination, which was not safe to drink by the consumer. Therefore, preventive actions should be taken to prevent foodborne illness outbreak in future


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.


1970 ◽  
Vol 24 (2) ◽  
pp. 163-165 ◽  
Author(s):  
Abdul Hussain Shar ◽  
Yasmeen F Kazi ◽  
Miandad Zardari ◽  
Irshad Hussain Soomro

Total coliform (TC) and faecal coliform (FC) bacteria were analyzed in drinking water of Khairpur city. Ninty samples were collected from main reservoir (source), distribution line and consumer taps. pH and residual chlorine of water samples were also determined. For bacteriological analysis inductively membrane filtration (MF) method was used for total coliform (TC) as well as faecal (FC) coliform bacteria. All samples were found contaminated with total coliform (TC) and faecal coliform (FC) and the counts were higher than the maximum microbial contaminant level (MMCL) established by World Health Organization (WHO). It was observed that pH was within the limits of WHO standard (6.5-8.5). The residual chlorine was not detected in any sample of drinking water. Bacteriologically the water quality of the drinking water is unsatisfactory.Keywords: Coliform, Escherichia coli, Water quality, Contamination, SanitationDOI: http://dx.doi.org/10.3329/bjm.v24i2.1266


Sign in / Sign up

Export Citation Format

Share Document