The use of antibiotic resistance profiling as a means of tracing sources of fecal contamination in source waters

2010 ◽  
Vol 10 (2) ◽  
pp. 209-215
Author(s):  
M. S. Mthembu ◽  
P. T. Biyela ◽  
T. G. Djarova ◽  
A. K. Basson
Keyword(s):  
Antibiotic Resistance ◽  
Municipal Wastewater ◽  
Fecal Contamination ◽  
Source Tracking ◽  
Human Consumption ◽  
Biochemical Tests ◽  
Isolation And Identification ◽  
E Coli ◽  
Intestinal Pathogens ◽  
Source Waters

Fecal contamination of source waters and its associated intestinal pathogens continues to pose risks to public health although the extent and effect of microbial contamination of source waters gets very little attention in designing treatment plants in most developing countries. Coliform counts give an indication of the overall bacterial contamination of water and thus its safety for human consumption. However, their presence fails to provide information about the source of fecal contamination which is vital to managing fecal contamination problems in surface waters. This study explored the use of multiple antibiotic resistance (MAR) indexing as means of differentiating E. coli isolates from different sources. A total of 322 E. coli isolates were obtained from municipal wastewater and from fecal samples from domestic and wild animals. Conventional culture methods and standard chemical and biochemical tests were used for isolation and identification of E. coli. Isolates were assayed against 10 antibiotics using the micro-dilution technique. The results obtained generated antibiotic resistance profiles which were used to statistically group the isolates into different subsets. Correct source classification was obtained for 60% of human-derived and 95% non-human-derived E. coli respectively. These results indicate the validity of the usefulness of MAR indexing as a method of bacterial source tracking.

Occurrence of antibiotic resistance inEscherichia colifrom surface waters and fecal pollution sources near Hamilton, Ontario

2005 ◽  
Vol 51 (6) ◽  
pp. 501-505 ◽  
Author(s):  
Thomas A Edge ◽  
Stephen Hill
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Surface Waters ◽  
Municipal Wastewater ◽  
Average Rate ◽  
Fecal Pollution ◽  
Pollution Sources ◽  
Source Tracking ◽  
E Coli ◽  
Bird Feces

Antibiotic resistance was examined in 462 Escherichia coli isolates from surface waters and fecal pollution sources around Hamilton, Ontario. Escherichia coli were resistant to the highest concentrations of each of the 14 antibiotics studied, although the prevalence of high resistance was mostly low. Two of 12 E. coli isolates from sewage in a CSO tank had multiple resistance to ampicillin, ciprofloxacin, gentamicin, and tetracycline above their clinical breakpoints. Antibiotic resistance was less prevalent in E. coli from bird feces than from municipal wastewater sources. A discriminant function calculated from antibiotic resistance data provided an average rate of correct classification of 68% for discriminating E. coli from bird and wastewater fecal pollution sources. The preliminary microbial source tracking results suggest that, at times, bird feces might be a more prominent contributor of E. coli to Bayfront Park beach waters than municipal wastewater sources.Key words: antibiotic resistance, Escherichia coli, surface water, fecal pollution.

An optimized enumeration method for sorbitol-fermenting Bifidobacteria in water samples

2005 ◽  
Vol 51 (5) ◽  
pp. 413-422 ◽  
Author(s):  
Sharon C Long ◽  
Catalina Arango P. ◽  
Jeanine D Plummer
Keyword(s):  
Membrane Filtration ◽  
Fecal Contamination ◽  
Domestic Wastewater ◽  
Microbial Source Tracking ◽  
Quantitative Information ◽  
Source Tracking ◽  
Human Consumption ◽  
Bromocresol Purple ◽  
Environmental Waters ◽  
Biochemical Tests

With increased focus on watershed protection under the Surface Water Treatment Rule, indicators that discriminate among sources of microbial inputs (microbial source tracking) are needed to supplement the quantitative information provided by total and fecal coliform measurements for drinking water monitoring. Bifidobacteria are found in the digestive tract and feces of humans and other animals, and also in sewage. Sorbitol is a food additive used exclusively in food intended for human consumption. Therefore, the presence of sorbitol-fermenting Bifidobacteria in environmental waters can be indicative of sources of human fecal contamination. A series of media were evaluated using ATCC cultures of B. breve and B. adolescentis, feces from different animals, and domestic wastewater samples. The media evaluated were Human Bifid Sorbitol agar (HBSA), modified Human Bifid Sorbitol agar, Beerens Medium, modified Beerens Medium, Reinforced Clostridial agar, BIM-25 Medium, and modified BIM-25 Medium. Variables such as sample preservation, incubation time, different pH indicators, plating technique, and discontinuous exposure to sorbitol were also evaluated. A series of biochemical tests were used to confirm positive colonies enumerated on the various media. Membrane filtration and enumeration of sodium sulfite preserved samples on HBSA containing bromocresol purple using loose lidded plates for 48 h provided the best recoveries for presumptive positive colonies. A number of sorbitol-fermenters that were not Bifidobacteria were able to grow on all media tested, resulting in false-positives. Therefore, plating on HBSA should be followed by a confirmation step when monitoring for sorbitol-fermenting Bifidobacteria in environmental waters. A year-long sampling survey of a managed reservoir in Massachusetts provided field validation of the proposed methodology for sorbitol-fermenting Bifidobacteria as a human-related source tracking indicator tool.Key words: sorbitol-fermenting Bifidobacteria, microbial source tracking, watershed management, fecal contamination.

scholarly journals Molecular characterization of Escherichia coli isolated from milk samples with regard to virulence factors and antibiotic resistance

2021 ◽  
pp. 2410-2418
Author(s):  
Waleed Younis ◽  
Sabry Hassan ◽  
Hams M. A. Mohamed
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
16S Rrna ◽  
Virulence Factors ◽  
Pathogenic Bacteria ◽  
Human Life ◽  
Raw Milk ◽  
Biochemical Tests ◽  
E Coli ◽  
Milk Samples

Background and Aim: Raw milk is considered an essential source of nutrition during all stages of human life because it offers a valuable supply of protein and minerals. Importantly, milk is considered a good media for the growth and contamination of many pathogenic bacteria, especially food-borne pathogens such as Escherichia coli. Thus, the objective of this study was to characterize E. coli and detect its virulence factors and antibiotic resistance from raw milk samples. Materials and Methods: Raw milk samples (n=100) were collected from different localities in Qena, Egypt, and investigated for the presence of E. coli using different biochemical tests, IMViC tests, serotyping to detect somatic antigen type, and molecularly by polymerase chain reaction (PCR) tests. The presence of different virulence and antimicrobial genes (hly, eae, stx1, stx2, blaTEM, tetA(A), and tetB genes) in E. coli isolates was evaluated using PCR. Results: The results demonstrated that 10 out of 100 milk samples were contaminated with E. coli. Depending on serology, the isolates were classified as O114 (one isolate), O27 (two isolates), O111 (one isolate), O125 (two isolates), and untypeable (five isolates) E. coli. The sequencing of partially amplified 16S rRNA of the untypeable isolates resulted in one isolate, which was initially misidentified as untypeable E. coli but later proved as Enterobacter hormaechei. Moreover, antibacterial susceptibility analysis revealed that nearly all isolates were resistant to more than 3 families of antibiotics, particularly to β-lactams, clindamycin, and rifampin. PCR results demonstrated that all E. coli isolates showed an accurate amplicon for the blaTEM and tetA(A) genes, four isolates harbored eae gene, other four harbored tetB gene, and only one isolate exhibited a positive stx2 gene. Conclusion: Our study explored vital methods for identifying E. coli as a harmful pathogen of raw milk using 16S rRNA sequencing, phylogenetic analysis, and detection of virulence factors and antibiotic-resistant genes.

scholarly journals Unveiling the Virulent Genotype and Unusual Biochemical Behavior of Escherichia coli ST59.

2021 ◽  
Author(s):  
Ana Carolina de Mello Santos ◽  
Bruna Fuga ◽  
Fernanda Esposito ◽  
Brenda Cardoso ◽  
Fernanda Fernandes Santos ◽  
...  
Keyword(s):  
Bacterial Species ◽  
Genomic Analysis ◽  
Epidemiological Studies ◽  
Sequence Type ◽  
Automatic Identification ◽  
Biochemical Tests ◽  
Isolation And Identification ◽  
E Coli ◽  
Metabolic Trait ◽  
Virulence Markers

Extraintestinal pathogenic E. coli (ExPEC) is a leading cause of human and animal infections worldwide. The utilization of selective and differential media to facilitate the isolation and identification of E. coli from complex samples as water, food, sediment, and the gut is common in epidemiological studies. During a surveillance study, we identified an E. coli strain isolated from human blood culture that displayed atypical light cream-colored colonies in chromogenic agar, being unable to produce β-glucuronidase and β-galactosidase enzymes in biochemical tests. Genomic analysis showed that the strain belongs to the sequence type ST59 and phylogroup F. The evaluation in silico of 104 available sequenced lineages of ST59 complex showed that most of them belong to serotype O1:K1:H7, are β-glucuronidase-negative, and harbor a virulent genotype associated with the presence of important virulence markers such as pap , kpsE , chuA , fyuA , and yfcV . Most of them were isolated from extraintestinal human infections in diverse countries worldwide and could be clustered/subgrouped based on papAF allele analysis. Considering that all analyzed strains harbor a virulent genotype, and most do not present the typical biochemical behavior of the E. coli species, we alert that they could be misclassified or underestimated, especially in epidemiological studies where the screening criteria rely only on typical biochemical phenotypes as happens when chromogenic media are used. Importance The usage of selective and differential media is a rule that guides presumptive bacterial identification based on specific metabolic traits that are specific to each bacterial species. When a bacterial specimen displays an unusual phenotype in these media, this characteristic may drive to bacterial misidentification or a significant delay in its identification, putting a patient at risk depending on the infection’s type. In the present work, we describe a virulent E. coli sequence type (ST59) that does not produce the beta-glucuronidase enzyme (GUS-negative), which is the metabolic trait widely used for E. coli presumptive identification in diverse differential media. The recognition of this unusual metabolic trait may help in the proper identification of ST59 isolates, the identification of their reservoir, and the evaluation of the frequency of these pathogens in places where automatic identification methodologies are not available.

scholarly journals Variation of Total Coliforms and Bacteria during Dry and Wet Seasons in Rivers of Sigor Division, West Pokot County, Kenya

2020 ◽  
pp. 41-51
Author(s):  
Nyasimi Ayora Gershom ◽  
Kirui Stella ◽  
Maingi John ◽  
Kebira Anthony
Keyword(s):  
Small Scale ◽  
Human Consumption ◽  
Wet Season ◽  
Biochemical Tests ◽  
E Coli ◽  
Urinary Infections ◽  
Shigella Species ◽  
West Pokot ◽  
Dry Seasons ◽  
Small Scale Farmers

Aims: There has been an increase in gastro-intestinal and urinary infections in Sigor division, West Pokot, Kenya. These infections result from bacteria and coliforms which are majorly propagated in water systems. Residents of this area are pastoralists and small-scale farmers relying on river water for their consumption and economic needs. This study aimed at characterizing the strains and quantities of bacteria and coliforms in the four rivers during the wet and dry seasons. Study Design:  An independent measures design was used. Place and Duration of Study: Samples were taken from four rivers (Weiwei, Chesogon, Lomut and Muruny) in Sigor division, West Pokot county, Kenya. The study was conducted between January and October 2013. Methodology: Sampling was done at various points of the river in a stratified manner for characterization and analysis. Four main pathogens namely E. coli, V. cholerae, Shigella and Salmonella species as well as F. streptococci were isolated, cultured using different media and characterized. Further biochemical tests were conducted to confirm the exact strains present. Total viable counts for the bacteria and coliforms were then enumerated. Results: The results found out that E. coli, V. cholerae, Salmonella and Shigella species were abundant in the rivers while F. streptococci were only observed during the wet season. Biochemical tests conducted on the isolates revealed that the strains co-existed in the water samples. Weiwei river had the greatest number of bacteria strains. Muruny river was found to have the largest population of bacteria colony forming units (cfu’s). There was a large disparity in cfu’s in the rivers during the dry seasons. Chesogon river had the highest population of coliform units. Conclusion: The raw water in all the rivers were concluded to be unsafe for human consumption according to WHO standards.

scholarly journals The Prevalence of Esbl-Producing Strains of E.coli, Isolated from Calves with Colibacilosis - Preliminary Remarks

2017 ◽  
Vol 74 (1) ◽  
pp. 129
Author(s):  
Andreea Paula COZMA ◽  
Ioana CRIVEI ◽  
Oana Alexandra CIOCAN ◽  
Catalin CARP-CARARE ◽  
Cristina RIMBU ◽  
...  
Keyword(s):  
Clinical Signs ◽  
Human Consumption ◽  
Beta Lactamase ◽  
Bacterial Strains ◽  
Isolation And Identification ◽  
Chromogenic Medium ◽  
Extended Spectrum Beta Lactamase ◽  
E Coli ◽  
Sterile Medium ◽  
Taxonomic Isolation

The animals producing food have become an increasing reservoir of extended spectrum beta-lactamase producing Enterobacteriaceae. The calves and cows are exposed to a greater quantity of antibiotics, but the data concerning the prevalence of ESBL-producing Enterobacteriaceae are not enough, in comparison with other species of animals used for human consumption, such as birds (Hordijk et al., 2013).The aim of this study was to determine the prevalence of ESBL-producing E. coli involved in some episodes of colibacilosis in calves. Faeces samples were collected from 33 calves with the age ranging between 1-2 weeks and that presented clinical signs of colibacilosis. The samples were collected in a sterile medium for the taxonomic isolation and identification of the etiological agent involved, the ESBL screening being conducted subsequently using the ESBL Agar Oxoid Brilliance chromogenic medium. The phenotypic confirmation of the ESBL-producing strains was conducted in accordance with the CLSI (2014) standard through the combined disc method. Following the tests conducted, out of the 33 strains of isolated E. coli, 9 (27, 27%) were phenotypically confirmed as being ESBL strains.The studies that were previously conducted on the dairy farms have pointed out that the young calves rapidly acquire bacterial strains resistant to antibiotics that are often ESBL strains (Hordijk et al., 2013). The prevalence obtained by us, as well as an insufficient quantity of information concerning the antimicrobial resistance on this segment of species of animals used for the human consumption, support conducting a more thorough study, as well as the identification of ESBL resistance genes, but also of the plasmids that encode the transmission of these genes.

Antibiotic Resistance of Escherichia coli Strains Isolated from Broiler Meat in Morocco

2020 ◽  
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Multidrug Resistant ◽  
Test Method ◽  
Poultry Meat ◽  
Epidemiological Surveillance ◽  
Human Consumption ◽  
First Line ◽  
Broiler Meat ◽  
E Coli

The spread of multidrug-resistant (MDR) enterobacteria worldwide is a major public health threat. Resistant to at least three classes of antibiotics, MDR enterobacteria cause infections that escape first-line treatment. Escherichia coli is the most frequently isolated bacterium in poultry industry. We followed the pattern and trend of antibiotic resistance of strains of E. coli isolated from poultry meat destined for human consumption sold in Morocco during the period 2016-2018, and thus detected strains that would be multidrug-resistant (MDR). In this study we investigated the resistance of 240 strains of E. coli isolated from poultry meat to 13 antibiotics by using the agar diffusion susceptibility test method. Results showed high resistance to ciprofloxacins (87.5%), tetracycline (75%), trimethomprime-sulfametoxazole (3rd generation) (70.8%), nalidixic acid (62.5%) and cefotaxime (50%), ampicillin (45.8%); and we detected low resistance to gentamicin (29.1%). In total, 50 isolated strains of E. coli (20.8%) have shown MDR. These results are useful to practicing veterinarians trying to avoid therapeutic failures and constitute an important database for pharmacovigilance and epidemiological surveillance of antimicrobial resistance in the country.

scholarly journals Screening for microbial load and antibiotic resistance pattern in Escherichia coli isolated from paper currency circulating in Kushtia, Bangladesh

2019 ◽  
Vol 7 (4) ◽  
pp. 1161 ◽  
Author(s):  
S. M. Raihan Rahman ◽  
Md. Nazim Uddin ◽  
Zulkar Nain ◽  
Mohammad Minnatul Karim
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Pathogenic Bacteria ◽  
Grocery Store ◽  
Human Beings ◽  
Isolation And Identification ◽  
Antibiotic Resistant ◽  
E Coli ◽  
Pseudomonas Spp ◽  
Paper Currency

Background: Paper currency is used for every type of commerce and plays an important role in the life of human beings. They are exchanged and come into contact with different environments and many different individuals during their circulation. Therefore, they can become contaminated with microorganisms and transfer bacteria across environments. The present study was aimed for quantitative assessment of microorganisms in circulated paper currency from Kushtia, Bangladesh and antibiotic resistant profiles of isolated Escherichia coli.Methods: A total of 10 paper currency samples currently in circulation involving three denominations (5, 10 and 500) were randomly collected from individuals involved in various occupations including street beggar, local hotel, bus conductor, poultry seller, vegetable seller, fish seller, commercial bank, ATM booth, tea seller, grocery store in Kushtia city, Bangladesh. Selective culture and biochemical tests were performed for the isolation and identification of microbial pathogens. Antibiotic resistance profiles were evaluated for isolated Escherichia coli using Kirby-Bauer method according to CLSI guidelines.Results: Aerobic mesophilic bacteria, Enterobacteriaceae and Pseudomonas spp. were the highest in paper currency from local hotel and ATM booth. Enterobacteriaceae (including coliforms) were predominantly present in paper currencies collected from local hotel, grocery, fish seller and beggar while Pseudomonas spp. were found in currency notes obtained from ATM booth, poultry farm, vegetable seller and local hotel. Antibiotic resistant profiles of E. coli isolated from local hotel currency showed that 50% of E. coli isolates were multidrug resistant. The highest resistant profile was observed against penicillin (95%) followed by polypeptide (75%), cephalosporin (50%), quinolone (30%) and sulfonamide (5%) groups of antibiotics.Conclusions: Multiple antibiotic resistant pathogenic bacteria are prevalent in paper currency regardless of their sources. Paper currency could contribute in transmission of infectious disease as well as in antibiotic resistance, therefore, should be handled carefully.

scholarly journals Isolation and Identification of Bacteria from the Workers of Live Bird Markets at Mymensingh, Bangladesh

1970 ◽  
Vol 17 ◽  
pp. 135-138
Author(s):  
S Sarker ◽  
S Talukder ◽  
EH Chowdhury ◽  
PM Das
Keyword(s):  
Escherichia Coli ◽  
Dna Isolation ◽  
Biochemical Tests ◽  
Isolation And Identification ◽  
E Coli ◽  
Live Bird Markets ◽  
Nasal Swabs ◽  
Identification Of Bacteria ◽  
Live Bird

Context: Identification of bacteria from the workers of live bird markets is important factor for zoonotic aspects and for implementing appropriate control strategies.Objectives: To determine the occurrence of bacteria especially Salmonella sp. and Escherichia coli from the workers of live bird markets.Materials and Methods: A total of 40 samples were collected from hand washes (n=20) and nasal swabs (n=20) of the associated workers in urban and suburban live bird markets. Bacteria were isolated in different media, and identification was performed based on the staining, cultural and some biochemical tests. For Salmonella sp., DNA was extracted using a DNA isolation kit and rfbs gene was amplified by using commercial PCR kit.Results: The bacteria such as Salmonella sp. and E. coli were detected in the samples by several microbial tests. The prevalence of Salmonella sp. was 40% and 30%, and E. coli was 70% and 40% in the hand washes and nasal swabs respectively of the workers of urban and periurban live bird markets.Conclusion: The results obtained in this study suggest that the appropriate precautions should be taken during and subsequent to the handling of live birds to minimize the risk of zoonotic diseases.Key words: Salmonella; Escherichia coli; live bird markets; isolation and identificationDOI: 10.3329/jbs.v17i0.7121J. bio-sci. 17: 135-138, 2009

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