Evaluation of Colilert-18® as an alternative method for monitoring total coliforms and Escherichia coli in some faecally polluted river waters

2014 ◽  
Vol 4 (4) ◽  
pp. 604-611
Author(s):  
Amanda S. Brand ◽  
Jo M. Barnes
Keyword(s):  
Escherichia Coli ◽  
Rank Correlation ◽  
Water Source ◽  
Polluted Water ◽  
Most Probable Number ◽  
Probable Number ◽  
Total Coliforms ◽  
E Coli ◽  
True Value ◽  
Significant Difference

The increase in numbers and contamination levels of faecally polluted water has resulted in shifts worldwide towards methods which enumerate faecal indicator bacteria faster. Rapid methods enable more timely remedial and preventative actions which protect the health of water users. However, especially in the developing world, straightforward methods are also preferred as they reduce the requirement for highly qualified analysts. This study investigates the feasibility of using the rapid, semi-automated enzyme substrate test Colilert-18® instead of multiple-tube fermentation (MTF) in total coliform and Escherichia coli enumeration for South African river water, as one example of a surface water source carrying considerable faecal pollution, which needs monitoring. Spearman rank correlation coefficients (ρ) of 0.83 and 0.86 were obtained for total coliforms and E. coli respectively, indicating Colilert-18® performed acceptably in the pollution ranges encountered. A Bland–Altman plot further revealed that Colilert-18® showed no significant difference (p > 0.05) from MTF values below 100,000 E. coli most probable number/100 mL (estimated true value). Above this level Colilert-18® was found to progressively underestimate E. coli. This inadequacy of Colilert-18® was considered acceptable from a health risk assessment viewpoint as such high counts should have sounded the alarm for preventative and corrective action irrespective of method inaccuracy.

scholarly journals Contamination Potentials of Household Water Handling and Storage Practices in Kirundo Subcounty, Kisoro District, Uganda

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Alexander Agensi ◽  
Julius Tibyangye ◽  
Andrew Tamale ◽  
Ezera Agwu ◽  
Christine Amongi
Keyword(s):  
Escherichia Coli ◽  
Drinking Water ◽  
Water Source ◽  
Water Sources ◽  
Most Probable Number ◽  
Probable Number ◽  
Total Coliforms ◽  
Water Handling ◽  
Significant Difference ◽  
And Storage

Introduction. Waterborne diseases constitute a major public health burden in developing and underdeveloped countries. Consumption of contaminated water causes health risk to the public, and the situation is alarming in rural areas. The objective of this study was to assess the contamination potentials of different house water handling and storage practices in the Kirundo subcounty, Kisoro District, Uganda. Material and Methods. A cross-sectional and descriptive study in which 344 water samples were collected randomly and analysed for bacteriological contamination, total coliforms (TCs) and Escherichia coli per 100 ml, using the Most Probable Number (MPN) technique and reported in terms of CFU/100 ml. Results. The 43.2% samples from unprotected water sources had total coliforms and 34.1% had Escherichia coli. In analysed household drinking water, 25% had total coliforms and 8.7% had Escherichia coli. Most drinking water sources were found to have coliform counts above the recommended national and international guidelines. There was a statistically significant difference among water sources with respect to total coliforms and Escherichia coli (p<0.05). Conclusion. The overall results indicated that there is a strong linkage between microbiological water quality and water source sanitation; hence, the protected water source was safer than unprotected water sources. For the unprotected water sources, protection strategies as well as monitoring are recommended for this community.

Recovery of Escherichia coli Biotype I and Enterococcus spp. during Refrigerated Storage of Beef Carcasses Inoculated with a Fecal Slurry

1999 ◽  
Vol 62 (8) ◽  
pp. 944-947 ◽  
Author(s):  
M. CALICIOGLU ◽  
D. R. BUEGE ◽  
S. C. INGHAM ◽  
J. B. LUCHANSKY
Keyword(s):  
Escherichia Coli ◽  
Storage Period ◽  
Most Probable Number ◽  
Probable Number ◽  
E Coli ◽  
Viable Cells ◽  
Beef Carcasses ◽  
Significant Difference ◽  
Enterococcus Spp ◽  
Appreciable Reduction

Three beef front quarters/carcasses were inoculated with a slurry of cattle manure. During storage at 4°C, two sponge samples from each of three sites (i.e., 100 cm2 from each of two fat surfaces and 100 cm2 from a lean surface) were taken from each of the three carcasses on days 0, 1, 3, 7, and 10 after inoculation. The initial numbers of Escherichia coli averaged 2.0 log10 CFU/cm2 (1.21 to 2.47 log10 CFU/cm2) using the Petrifilm method and 2.09 log10 most probable number (MPN)/cm2 (0.88 to 2.96 log10 MPN/cm2) using the MPN method. The initial numbers of enterococci averaged 3.34 log10 CFU/cm2 (3.07 to 3.79 log10 CFU/cm2) using kanamycin esculin azide agar. In general, an appreciable reduction in the numbers of E. coli occurred during the first 24 h of storage; for the Petrifilm method an average reduction of 1.37 log10 CFU/cm2 (0.69 to 1.71 log10 CFU/cm2) was observed, and for the MPN method an average reduction of 1.52 log10 MPN/cm2 (0.47 to 2.08 log10 MPN/cm2) was observed. E. coli were not detected (&lt;−0.12 log10 CFU/cm2) using Petrifilm on day 7 of the storage period on two (initial counts of 1.21 and 2.29 log10 CFU/cm2) of the three carcasses. However, viable E. coli cells were recovered from these two carcasses after a 24-h enrichment at 37°C in EC broth. Viable E. coli cells were detected at levels of −0.10 log10 CFU/cm2 on the third carcass (initial count of 2.47 log10 CFU/cm2) after 7 days at 4°C. No significant difference in recovery of viable cells was observed between the MPN and Petrifilm methods on days 0, 1, and 3 (P &gt; 0.05). However, viable E. coli cells were recovered from all three carcasses by the MPN method on day 7 at an average of −0.29 log10 MPN/cm2 (−0.6 to −0.1 log10 MPN/cm2). On day 10, viable cells were recovered by the MPN method from two of the three carcasses at −0.63 and −0.48 log10 MPN/cm2 but were not recovered from the remaining carcass (&lt;−0.8 log10 MPN/cm2). Similar to E. coli, the greatest reduction (average of 1.26 log10 CFU/cm2, range = 1.06 to 1.45 log10 CFU/cm2) in the numbers of enterococci occurred during the first 24 h of storage. Because of higher initial numbers and a slightly slower rate of decrease, the numbers of Enterococcus spp. were significantly higher (P &lt; 0.017) than the numbers of E. coli Biotype I after 3, 7, and 10 days of storage. These results suggest that enterococci may be useful as an indicator of fecal contamination of beef carcasses.

ColiComplete® Substrate-Supporting Disc Method for Confirmed Detection of Total Coliforms and Escherichia coli in All Foods: Comparative Study

1994 ◽  
Vol 77 (1) ◽  
pp. 58-63 ◽  
Author(s):  
Philip T Feldsine ◽  
Maria T Falbo-Nelson ◽  
David L Hustead
Keyword(s):  
Escherichia Coli ◽  
Comparative Study ◽  
Total Coliform ◽  
Coliform Bacteria ◽  
Most Probable Number ◽  
Probable Number ◽  
Total Coliforms ◽  
E Coli ◽  
Total Coliform Bacteria ◽  
Better Than

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.

scholarly journals Escherichia coli contamination of groundwater in Metro City, Lampung

2021 ◽  
Vol 277 ◽  
pp. 04001
Author(s):  
Qanza Nurul Jannah ◽  
Gita Lestari Putri
Keyword(s):  
Escherichia Coli ◽  
Water Source ◽  
Water Sources ◽  
Most Probable Number ◽  
Probable Number ◽  
E Coli ◽  
Groundwater Samples ◽  
Who Standards ◽  
Different Types ◽  
Very High

Groundwater sources are widely used to supply water for drinking and other domestic purposes in Metro City, Indonesia. The presence of Escherichia coli (E. coli) is an indicator of fecal contamination in the water source. Therefore, this study was conducted to assess the level of E. coli contamination in groundwater at Metro City. The analysis was conducted on 253 households in 5 sub-districts using groundwater samples from different types of wells such as boreholes, protected wells, and unprotected wells. The E. coli concentrations were determined using the Colilert-18 method with IDEXX Quanti-Tray 2000 and the results showed the highest levels of contamination were in unprotected wells. E. coli was detected in 71% of water sources with 36% classified as very high risk or above 100 MPN (Most Probable Number)/100ml based on WHO standards. The findings, showed that the protection of water sources has the ability to reduce the risk of contamination.

Use of the Chromogenic Substrate 5-Bromo-4-Chloro-3-Indolyl-B-D-Glucuronide (X-GLUC) for Enumerating Escherichia coli in 24 H from Ground Beef

1990 ◽  
Vol 53 (6) ◽  
pp. 508-510 ◽  
Author(s):  
LAWRENCE RESTAINO ◽  
ELON W. FRAMPTON ◽  
RICHARD H. LYON
Keyword(s):  
Escherichia Coli ◽  
Ground Beef ◽  
Most Probable Number ◽  
Chromogenic Substrate ◽  
Probable Number ◽  
E Coli ◽  
Glucuronidase Activity ◽  
Significant Difference ◽  
Plating Method ◽  
Positive Linear Correlation

A 24-h direct plating method for Escherichia coli using the chromogenic substrate 5-bromo-4-chloro-3-indolyl-B-D-glucuronide (X-GLUC) incorporated into a Peptone-tergitol agar base (PTX) was compared with the standard 3-tube Most Probable Number (MPN) method on 50 naturally contaminated ground beef samples. A paired-comparisons t-test showed no significant difference between the two methods. A positive linear correlation between the two methods was observed over the entire range of values. Ninety-seven percent of the positive colonies (blue colonies) on PTX agar were indentified as E. coli, whereas no atypical colonies (nonblue) were characterized as such. Thus, a simple and reliable enumeration of E. coli can be made within 24 h using the X-GLUC substrate in a selective agar as an indicator of B-glucuronidase activity.

Comparison of β-Glucuronidase and Indole-Based Direct Plating Methods for Enumerating Escherichia coli in Artificially Inoculated Ground Meats

1990 ◽  
Vol 53 (11) ◽  
pp. 933-935 ◽  
Author(s):  
ELON W. FRAMPTON ◽  
LAWRENCE RESTAINO ◽  
NANCY BLASZKO
Keyword(s):  
Escherichia Coli ◽  
Ground Beef ◽  
Plate Count ◽  
Most Probable Number ◽  
Probable Number ◽  
E Coli ◽  
Glucuronidase Activity ◽  
Plate Count Agar ◽  
Significant Difference ◽  
Indole Production

Peptone tergitol glucuronide (PTG) agar containing 4-methylumbelliferyl-β-D glucuronide (MUG) (for β-glucuronidase activity), the Holbrook, Anderson, Baird-Parker (HABP) method (for detecting indole production), and the standard 3-tube most probable number (MPN) method were compared with plate count agar (PCA) for enumerating three strains of unstressed Escherichia coli artificially inoculated into ground beef and chicken at 1–6 × 106 cells/g. No significant difference (P&gt;0.05) was determined between PTG agar and PCA in the recovery of E. coli. The MPN method enumerated a significantly greater (P&lt;0.05) number of E. coli cells than PCA. Compared with PCA, the HABP method recovered a significantly lower (P&lt;0.05) number of E. coli cells from chicken, whereas no significant difference (P&gt;0.05) was obtained with ground beef. When combining all data from chicken and beef, the recovery of E. coli cells by the HABP method was also significantly lower (P&lt;0.05). Overall, based on the enumeration of E. coli on PCA, the HABP method, PTG agar, and MPN method recovered 57, 102, and 144%, respectively.

Recovery of Salmonellae from Chilled Broiler Carcasses as Affected by Rinse Media and Enumeration Method

1992 ◽  
Vol 55 (5) ◽  
pp. 329-332 ◽  
Author(s):  
J. P. JETTON ◽  
S. F. BILGILI ◽  
D. E. CONNER ◽  
J. S. KOTROLA ◽  
M. A. REIBER
Keyword(s):  
Escherichia Coli ◽  
Aerobic Bacteria ◽  
Most Probable Number ◽  
Distilled Water ◽  
Significant Trial ◽  
Probable Number ◽  
Total Coliforms ◽  
E Coli

Distilled water (DW) and 0.85% NaCl (PS) were evaluated as carcass rinse media for recovery of total aerobic bacteria (APC), total coliforms (TC), Escherichia coli, and salmonellae from broiler carcasses. Salmonellae were enumerated by two methods, most-probable-number (MPN) and centrifugation-plating onto dulcitol novobiocin agar (DBN). Commercially processed chilled broiler carcasses (10/trial, 3 trials) were aseptically cut in half, and each half was rinsed (1 min) with either 250 ml DW or PS. Carcass rinses were recovered and analyzed for populations of APC, TC, E. coli, and salmonellae. Recovery of APC, TC, and E. coli were not affected (P&gt;.05) by rinse media; however, significant trial effects were present. Recovery of salmonellae was influenced by rinse media as well as by enumeration method. Using the MPN procedure, salmonellae were detected on 20 and 27% of carcass halves using PS and DW, respectively, whereas with DBN, salmonellae were recovered from 33% of PS-rinsed carcass halves and none of those rinsed with DW. Incidence of salmonellae on individual carcass halves did not correlate between either the two enumeration methods or rinse media. With both enumeration methods, the extent of salmonellae contamination was &lt;1 CFU/ml of rinse media. Rinsing carcasses with PS offered no advantages for recovery of APC, TC, and E. coli; however, salmonellae recovery on DBN was enhanced by PS as compared to DW rinse.

scholarly journals Lessons from a large outbreak of Escherichia coli O157[ratio ]H7 infections: insights into the infectious dose and method of widespread contamination of hamburger patties

1999 ◽  
Vol 122 (2) ◽  
pp. 185-192 ◽  
Author(s):  
J. TUTTLE ◽  
T. GOMEZ ◽  
M. P. DOYLE ◽  
J. G. WELLS ◽  
T. ZHAO ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Ground Beef ◽  
Most Probable Number ◽  
Strong Argument ◽  
Probable Number ◽  
Infectious Dose ◽  
E Coli ◽  
Beef Patties ◽  
Large Outbreak ◽  
Microbiological Testing

Between November 1992 and February 1993, a large outbreak of Escherichia coli O157[ratio ]H7 infections occurred in the western USA and was associated with eating ground beef patties at restaurants of one fast-food chain. Restaurants that were epidemiologically linked with cases served patties produced on two consecutive dates; cultures of recalled ground beef patties produced on those dates yielded E. coli O157[ratio ]H7 strains indistinguishable from those isolated from patients, confirming the vehicle of illness. Seventy-six ground beef patty samples were cultured quantitatively for E. coli O157[ratio ]H7. The median most probable number of organisms was 1·5 per gram (range, <0·3–15) or 67·5 organisms per patty (range, <13·5–675). Correlation of the presence of E. coli O157[ratio ]H7 with other bacterial indicators yielded a significant association between coliform count and the presence of E. coli O157[ratio ]H7 (P=0·04). A meat traceback to investigate possible sources of contamination revealed cattle were probably initially colonized with E. coli O157[ratio ]H7, and that their slaughter caused surface contamination of meat, which once combined with meat from other sources, resulted in a large number of contaminated ground beef patties. Microbiological testing of meat from lots consumed by persons who became ill was suggestive of an infectious dose for E. coli O157[ratio ]H7 of fewer than 700 organisms. These findings present a strong argument for enforcing zero tolerance for this organism in processed food and for markedly decreasing contamination of raw ground beef. Process controls that incorporate microbiological testing of meat may assist these efforts.

scholarly journals Mechanically Ventilated Broiler Sheds: a Possible Source of Aerosolized Salmonella, Campylobacter, and Escherichia coli

2009 ◽  
Vol 75 (23) ◽  
pp. 7417-7425 ◽  
Author(s):  
H. N. Chinivasagam ◽  
T. Tran ◽  
L. Maddock ◽  
A. Gale ◽  
P. J. Blackall
Keyword(s):  
Escherichia Coli ◽  
Most Probable Number ◽  
Production Cycle ◽  
Airborne Bacteria ◽  
Probable Number ◽  
Mechanically Ventilated ◽  
The Public ◽  
E Coli ◽  
Poultry Farms ◽  
Low Levels

ABSTRACT This study assessed the levels of two key pathogens, Salmonella and Campylobacter, along with the indicator organism Escherichia coli in aerosols within and outside poultry sheds. The study ranged over a 3-year period on four poultry farms and consisted of six trials across the boiler production cycle of around 55 days. Weekly testing of litter and aerosols was carried out through the cycle. A key point that emerged is that the levels of airborne bacteria are linked to the levels of these bacteria in litter. This hypothesis was demonstrated by E. coli. The typical levels of E. coli in litter were ∼108 CFU g−1 and, as a consequence, were in the range of 102 to 104 CFU m−3 in aerosols, both inside and outside the shed. The external levels were always lower than the internal levels. Salmonella was only present intermittently in litter and at lower levels (103 to 105 most probable number [MPN] g−1) and consequently present only intermittently and at low levels in air inside (range of 0.65 to 4.4 MPN m−3) and once outside (2.3 MPN m−3). The Salmonella serovars isolated in litter were generally also isolated from aerosols and dust, with the Salmonella serovars Chester and Sofia being the dominant serovars across these interfaces. Campylobacter was detected late in the production cycle, in litter at levels of around 107 MPN g−1. Campylobacter was detected only once inside the shed and then at low levels of 2.2 MPN m−3. Thus, the public health risk from these organisms in poultry environments via the aerosol pathway is minimal.

scholarly journals GREEN SYNTHESIS OF MAGNETIC IRON NANOPARTICLES USING MEDICINAL PLANT TRIDAX PROCUMBENS LEAF EXTRACTS AND ITS APPLICATION AS AN ANTIMICROBIAL AGENT AGAINST E. COLI

2020 ◽  
pp. 34-39
Author(s):  
YOJANA Y. PATIL ◽  
VAISHNVI B. SUTAR ◽  
ARPITA P. TIWARI
Keyword(s):  
Escherichia Coli ◽  
Magnetic Nanoparticles ◽  
Iron Nanoparticles ◽  
Most Probable Number ◽  
Leaf Extracts ◽  
Probable Number ◽  
Gram Negative ◽  
E Coli ◽  
Tridax Procumbens ◽  
Escherichia Coli Bacteria

Objective: The present study was aimed at the biological synthesis of magnetic iron nanoparticles by using the plant extract of Tridax procumbens and also to study their antimicrobial property against gram-negative bacteria (Escherichia coli). Methods: The synthesis of magnetic iron nanoparticles was carried out by the co-precipitation method using biological methods like plant extract as reducing agent and capping agents are biocompatible and non-hazardous. These nanoparticles were characterized by UV-Visible spectroscopy, XRD (X-Ray Diffraction), and SEM (Scanning Electron Microscope). As well as antibacterial activity of the nanoparticles was carried out by agar well diffusion method and Most Probable Number (MPN) method against gram-negative E. coli (Escherichia coli) bacteria. Results: The average crystallite size of Magnetic Nanoparticles (MNPs) was found to be 72 nm by X-ray diffraction. The optical absorption band at wavelengths of 240 nm and 402 nm was obtained from the UV Visible spectrum. Spherical shape morphology was observed in SEM studies. The antibacterial assay clearly expressed that E. coli showed a maximum zone of inhibition (15±0.15 mm) at 2 mg/ml and 1 mg/ml concentration was found for Magnetic Nanoparticles. In the Most Probable Number (MPN) test it is seen that the bacterial count is reduced after adding synthesized NPs into the water sample. Conclusion: The results of the present study conclude that the Magnetic Nanoparticles synthesized using Tridax procumbens leaf extracts is found to be stable and show good antibacterial activity against gram-negative (Escherichia coli) bacteria.

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