Phenotypic and Genotypic Characterization of Escherichia coli Isolated from Untreated Surface Waters

A common member of the intestinal microbiota in humans and animals isEscherichia coli. Based on the presence of virulence factors,E. colican be potentially pathogenic. The focus of this study was to isolateE. colifrom untreated surface waters (37 sites) in Illinois and Missouri and determine phenotypic and genotypic diversity among isolates. Water samples positive for fecal coliforms based on the Colisure®test were streaked directly onto Eosin Methylene Blue (EMB) agar (37°C) or transferred to EC broth (44.5°C). EC broth cultures producing gas were then streaked onto EMB agar. Forty-five isolates were identified asE. coliusing API 20E and Enterotube II identification systems, and some phenotypic variation was observed in metabolism and fermentation. Antibiotic susceptibility of each isolate was also determined using the Kirby-Bauer Method. Differential responses to 10 antimicrobial agents were seen with 7, 16, 2, and 9 of the isolates resistant to ampicillin, cephalothin, tetracycline, and triple sulfonamide, respectively. All of the isolates were susceptible or intermediate to amoxicillin, ciprofloxacin, polymyxin B, gentamicin, imipenem, and nalidixic acid. Genotypic variation was assessed through multiplex Polymerase Chain Reaction for four virulence genes (stx1andstx2[shiga toxin],eaeA[intimin]; andhlyA[enterohemolysin]) and one housekeeping gene (uidA[β-D-glucuronidase]). Genotypic variation was observed with two of the isolates possessing the virulence gene (eaeA) for intimin. These findings increase our understanding of the diversity ofE. coliin the environment which will ultimately help in the assessment of this organism and its role in public health.

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Molecular characterisation of antimicrobial resistance and virulence genes in Escherichia coli strains isolated from diarrhoeic and healthy rabbits in Tunisia

World Rabbit Science ◽

10.4995/wrs.2020.10879 ◽

2020 ◽

Vol 28 (2) ◽

pp. 81

Author(s):

Raouia Ben Rhouma ◽

Ahlem Jouini ◽

Amira Klibi ◽

Safa Hamrouni ◽

Aziza Boubaker ◽

...

Keyword(s):

Escherichia Coli ◽

Antimicrobial Resistance ◽

Virulence Genes ◽

Antimicrobial Agents ◽

Antibiotic Resistance Genes ◽

Virulence Gene ◽

Diffusion Method ◽

Class 1 Integron ◽

E Coli ◽

Class 1

The purpose of this study was to identify Escherichia coli isolates in diarrhoeic and healthy rabbits in Tunisia and characterise their virulence and antibiotic resistance genes. In the 2014-2015 period, 60 faecal samples from diarrhoeic and healthy rabbits were collected from different breeding farms in Tunisia. Susceptibility to 14 antimicrobial agents was tested by disc diffusion method and the mechanisms of gene resistance were evaluated using polymerase chain reaction and sequencing methods. Forty E. coli isolates were recovered in selective media. High frequency of resistance to tetracycline (95%) was detected, followed by different levels of resistance to sulphonamide (72.5%), streptomycin (62.5%), trimethoprim-sulfamethoxazole (60%), nalidixic acid (32.5%), ampicillin (37.5%) and ticarcillin (35%). E. coli strains were susceptible to cefotaxime, ceftazidime and imipenem. Different variants of blaTEM, tet, sul genes were detected in most of the strains resistant to ampicillin, tetracycline and sulphonamide, respectively. The presence of class 1 integron was studied in 29 sulphonamide-resistant E. coli strains from which 15 harboured class 1 integron with four different arrangements of gene cassettes, dfrA17+aadA5 (n=9), dfrA1 + aadA1 (n=4), dfrA12 + addA2 (n=1), dfrA12+orf+addA2 (n=1). The qnrB gene was detected in six strains out of 13 quinolone-resistant E. coli strains. Seventeen E. coli isolates from diarrhoeic rabbits harboured the enteropathogenic eae genes associated with different virulence genes tested (fimA, cnf1, aer), and affiliated to B2 (n=8) and D (n=9) phylogroups. Isolated E. coli strains from healthy rabbit were harbouring fim A and/or cnf1 genes and affiliated to A and B1 phylogroups. This study showed that E. coli strains from the intestinal tract of rabbits are resistant to the widely prescribed antibiotics in medicine. Therefore, they constitute a reservoir of antimicrobial-resistant genes, which may play a significant role in the spread of antimicrobial resistance. In addition, the eae virulence gene seemed to be implicated in diarrhoea in breeder rabbits in Tunisia.

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Extraintestinal Escherichia coli Carrying Virulence Genes in Coastal Marine Sediments

Applied and Environmental Microbiology ◽

10.1128/aem.03138-09 ◽

2010 ◽

Vol 76 (17) ◽

pp. 5659-5668 ◽

Cited By ~ 42

Author(s):

G. M. Luna ◽

C. Vignaroli ◽

C. Rinaldi ◽

A. Pusceddu ◽

L. Nicoletti ◽

...

Keyword(s):

Escherichia Coli ◽

Marine Sediments ◽

Large Scale ◽

Microbiological Quality ◽

Genotypic Diversity ◽

Coastal Sediments ◽

Fecal Coliforms ◽

Biochemical Tests ◽

Term Survival ◽

E Coli

ABSTRACT Despite the recognized potential of long-term survival or even growth of fecal indicators bacteria (FIB) in marine sediments, this compartment is largely ignored by health protection authorities. We conducted a large-scale study over approximately 50 km of the Marche coasts (Adriatic Sea) at depths ranging from 2 to 5 m. Total and fecal coliforms (FC) were counted by culture-based methods. Escherichia coli was also quantified using fluorescence in situ hybridization targeting specific 16S rRNA sequences, which yielded significantly higher abundances than culture-based methods, suggesting the potential importance of viable but nonculturable E. coli cells. Fecal coliforms displayed high abundances at most sites and showed a prevalence of E. coli. FC isolates (n = 113) were identified by API 20E, additional biochemical tests, and internal transcribed spacer-PCR. E. coli strains, representing 96% of isolates, were then characterized for genomic relatedness and phylogenetic group (A, B1, B2, and D) of origin by randomly amplified polymorphic DNA and multiplex-PCR. The results indicated that E. coli displayed a wide genotypic diversity, also among isolates from the same station, and that 44 of the 109 E. coli isolates belonged to groups B2 and D. Further characterization of B2 and D isolates for the presence of 11 virulence factor genes (pap, sfa/foc, afa, eaeA, ibeA, traT, hlyA, stx 1, stx 2, aer, and fyuA) showed that 90% of B2 and 65% of D isolates were positive for at least one of these. Most of the variance of both E. coli abundance and assemblage composition (>62%) was explained by a combination of physical-chemical and trophic variables. These findings indicate that coastal sediments could represent a potential reservoir for commensal and pathogenic E. coli and that E. coli distribution in marine coastal sediments largely depends upon the physical and trophic status of the sediment. We conclude that future sampling designs aimed at monitoring the microbiological quality of marine coastal areas should not further neglect the analysis of the sediment and that monitoring of these environments can be improved by including molecular methods as a complement of culture-based techniques.

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Molecular and phenotypic typing of enteropathogenic Escherichia coli isolated in childhood acute diarrhea in Abuja, Nigeria

The Journal of Infection in Developing Countries ◽

10.3855/jidc.9338 ◽

2017 ◽

Vol 11 (07) ◽

pp. 527-535 ◽

Cited By ~ 1

Author(s):

Casmir Ifeanyichukwu Cajetan Ifeanyi ◽

Nkiruka Florence Ikeneche ◽

Bassey Enya Bassey ◽

Stefano Morabito ◽

Caterina Graziani ◽

...

Keyword(s):

Escherichia Coli ◽

Acute Diarrhea ◽

Antimicrobial Agents ◽

Virulence Gene ◽

Enteropathogenic Escherichia Coli ◽

Extended Spectrum Beta Lactamase ◽

E Coli ◽

Typical Epec ◽

Marked Resistance

Introduction: Enteropathogenic Escherichia coli (EPEC) causes infectious diarrhea among children in developing countries. However, in Nigeria, due to limited laboratory resources, the genetic diversity of its virulence factors, which include intimin subtypes, remains undefined. Methodology: EPEC isolates from diarrheic children 60 months of age and younger in Abuja, Nigeria, were analyzed. Polymerase chain reaction (PCR) for EPEC virulence gene, Hep-2 cell adherence, and serotyping were performed. EPEC strains were further subtyped by PCR for the identification of intimin subtype genes α (alpha), β (beta), γ1 (gamma-1), and έ (epsilon). Antibiotic resistance and extended-spectrum beta-lactamase (ESBL) production was determined by Clinical and Laboratory Standards Institute guidelines. Results: Overall, 18 (4.5%) out of 400 children with acute diarrhea had EPEC infection. Typical EPEC (tEPEC) strains were detected in 14 (3.5%), whereas 4 (1.1%) were atypical EPEC (aEPEC). A total of 15 (83.3%) of the EPEC isolated belonged to β intimin subtype gene, while the remaining 3 EPEC isolates possessed the intimin έ subtype. No α and γ intimin subtypes were detected. Traditional EPEC serotypes O114:H14 were detected only in tEPEC strains. Marked resistance to β-lactam agents were observed but no ESBL-producing tEPEC or aEPEC was detected. Conclusions: This is the first report of intimin subtype genes in Abuja, Nigeria. EPEC isolates of diverse serotypes resistant to β-lactam antimicrobial agents were observed. These data will be useful in facilitating the characterization of intimin variants of EPEC and some Shiga toxin-producing E. coli (STEC) in humans and other animal species.

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Isolation of atypical enteropathogenic Escherichia coli from children with and without diarrhoea in Delhi and the National Capital Region, India

Journal of Medical Microbiology ◽

10.1099/jmm.0.014530-0 ◽

2010 ◽

Vol 59 (10) ◽

pp. 1156-1162 ◽

Cited By ~ 17

Author(s):

Pankaj Kumar Ghosh ◽

Arif Ali

Keyword(s):

Escherichia Coli ◽

Antimicrobial Agents ◽

Virulence Gene ◽

Healthy Children ◽

National Capital Region ◽

Capital Region ◽

E Coli ◽

Atypical Epec ◽

National Capital ◽

Typical Epec

A total of 17 typical and atypical enteropathogenic Escherichia coli (EPEC) were isolated from 396 children with and without diarrhoea. Out of 12 EPEC isolates from patients with diarrhoea, 3 (25 %) were atypical EPEC while 9 (75 %) were typical EPEC. It was observed that atypical EPEC strains had colonized the intestines of healthy children and its isolation rates were higher in healthy children than in children with diarrhoea. Interestingly all of the atypical EPEC isolates carried a megaplasmid, mostly comparable with the size of EPEC adherence factor (EAF) encoding gene but no virulence gene was detected in this megaplasmid. Studies also indicated that multidrug resistance EPEC are emerging and all the atypical EPEC strains showed significantly less resistance to all antimicrobial agents used in this study than typical EPEC. This study also supports the opinion that Shiga toxin-producing E. coli does not pose a major threat to human health in India. Subtyping analysis reveals that eae-α1, eae-β2 and eae-λ could be common EPEC subtypes prevalent in children with diarrhoea in Delhi. The present study is believed to be the first report of the detection of atypical EPEC from children without diarrhoea and records of isolation of eae-γ1, eae-γ2 and the rare eae-λ subtype in India. The data also indicated that typical EPEC are a common cause of diarrhoea and atypical EPEC are emerging as colonizers of the intestine of children with and without diarrhoea in Delhi and the National Capital Region, India.

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Genotypic Diversity and Antimicrobial Resistance of Escherichia Coli Isolated From Pigs in Hubei, China

10.21203/rs.3.rs-942081/v1 ◽

2021 ◽

Author(s):

Xiaoyue Li ◽

Zewen Liu ◽

Ningning Wang ◽

Wei Liu ◽

Ting Gao ◽

...

Keyword(s):

Escherichia Coli ◽

Genetic Diversity ◽

Antimicrobial Resistance ◽

Antimicrobial Agents ◽

Genotypic Diversity ◽

Hubei Province ◽

Economic Losses ◽

Multi Drug Resistance ◽

Growth Delay ◽

E Coli

Abstract BackgroundIntestinal infections with Escherichia coli (E. coli) are mostly occur in piglets between 1~10 days old, which major lead to diarrhea and edema in newborn piglets. These diseases caused by E. coli can increase mortality, morbidity and growth delay of piglets, which are responsible for economic losses. In this study was to investigate the prevalence of antibiotic resistance, transmission mechanisms, and molecular epidemiology of E. coli strains isolated from pig farms in Hubei province. Furthermore, clonal and genetic diversity of isolates were identified. ResultsA total of 29 E. coli isolates were obtained from fecal of weaned piglets from Hubei province. The E. coli isolates in different regions demonstrate different genetic diversity. Multilocus sequence typing (MLST) presented that ST165 was the common sequence type, accounting for 27.6% of all E. coli isolates, followed by ST744, ST1081, ST101 and ST10. All of the isolates were resistant to the tested antibiotics to vary degrees, and more than 80% of E. coli isolates presented high resistance rates to ampicillin, lincomycin, doxycycline, tetracycline, sulfaisoxazole and ampicillin. There was one E. coli strain that was resistant to the fifteen antimicrobial agents tested. Overall, most of the isolates were conferring resistance to 5-7 antimicrobial agents tested.ConclusionsOur study reported E. coli isolates with high antimicrobial resistance and explores the genetic diversity of E. coli isolated from swine-origin. From the results obtained it can be concluded that these isolates present high prevalent multi-drug resistance. These data provide a greater understanding of the genetic diversity and antimicrobial resistance of E. coli.

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Occurrence of Colibacillosis in Broilers and Its Relationship With Avian Pathogenic Escherichia coli (APEC) Population Structure and Molecular Characteristics

Frontiers in Veterinary Science ◽

10.3389/fvets.2021.737720 ◽

2021 ◽

Vol 8 ◽

Author(s):

Ilias Apostolakos ◽

Andrea Laconi ◽

Lapo Mughini-Gras ◽

Özlem Şahan Yapicier ◽

Alessandra Piccirillo

Keyword(s):

Escherichia Coli ◽

Population Structure ◽

Virulence Gene ◽

Genotypic Diversity ◽

Economic Loss ◽

Molecular Characteristics ◽

E Coli ◽

Broiler Production ◽

Pathogenic Escherichia Coli ◽

Production Stages

Avian pathogenic Escherichia coli (APEC) causes colibacillosis, the disease with the highest economic loss for the broiler industry. However, studies focusing on the prevalence and population structure of APEC in the broiler production pyramid are scarce. Here, we used genotyping and serotyping data to elucidate the APEC population structure and its changes in different broiler production stages along with whole-genome sequencing (WGS) in a subset of APEC isolates to determine transmission patterns amongst dominant APEC sequence types (STs) and characterize them in detail. Comparison of genotypes encountered in both APEC and avian fecal E. coli (AFEC) provided further insights. Overall, APEC-related mortality, as the proportion of the total sampled mortality in the broiler production, was high (35%), while phylogroup C and serogroup O78 were predominant amongst APEC isolates. We found a low (34.0%) and high (53.3%) incidence of colibacillosis in chicks and end-cycle broilers, respectively, which may be related to a shift in APEC genotypes, suggesting a trend from commensalism to pathogenicity across different broiler production stages. Despite considerable APEC genotypic diversity, there was substantial genotype overlap (40.9%, overall) over the production stages and convergence of STs to the four clusters. Within these clusters, WGS data provided evidence of clonal transmission events and revealed an enriched virulence and resistance APEC repertoire. More specifically, sequenced APEC were assigned to defined pathotypes based on their virulence gene content while the majority (86%) was genotypically multi-drug resistant. Interestingly, WGS-based phylogeny showed that a subset of APEC, which are cephalosporin-resistant, may originate directly from cephalosporin-resistant AFEC. Finally, exploration of the APEC plasmidome indicated that the small fraction of the APEC virulome carried by IncF plasmids is pivotal for the manifestation of the APEC pathotype; thus, plasmid exchange can promote pathogenicity in strains that are at the edge of the commensal and pathogenic states.

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Phylogenetic Backgrounds and Virulence-Associated Traits of Escherichia coli Isolates from Surface Waters and Diverse Animals in Minnesota and Wisconsin

Applied and Environmental Microbiology ◽

10.1128/aem.01329-17 ◽

2017 ◽

Vol 83 (24) ◽

Cited By ~ 3

Author(s):

James R. Johnson ◽

Brian D. Johnston ◽

Parissa Delavari ◽

Paul Thuras ◽

Connie Clabots ◽

...

Keyword(s):

Escherichia Coli ◽

Surface Water ◽

Human Health ◽

Surface Waters ◽

Animal Species ◽

Virulence Gene ◽

Content Type ◽

E Coli ◽

Animal Source ◽

Animal Isolates

ABSTRACT Possible external reservoirs for extraintestinal pathogenic Escherichia coli (ExPEC) strains that cause infections in humans are poorly defined. Because of the tremendous human health importance of ExPEC infections, we assessed surface waters and domesticated and wild animals in Minnesota and Wisconsin as potential reservoirs of ExPEC of human health relevance. We characterized 595 E. coli isolates (obtained from 1999 to 2002; 280 from seven surface water sites, 315 from feces of 13 wild and domesticated animal species) for phylogroup and virulence genotype, including inferred ExPEC status, by using multiplex PCR-based methods. We also compared the pulsed-field gel electrophoresis (PFGE) profiles of the isolates with a large private PFGE profile library. We found a predominance of non-ExPEC strains (95% and 93% among water and animal isolates, respectively), which were mainly from phylogroups A and B1, plus a minority of ExPEC strains (5% and 7% among water isolates and animal isolates, respectively), predominantly from phylogroup B2. The ExPEC strains, although significantly associated with cats, dogs, and turkeys, occurred in several additional animal species (goat, horse, chicken, pig) and were distributed broadly across all surface water sites. Virulence gene content among the animal source ExPEC isolates segregated significantly in relation to host species, following established patterns. PFGE analysis indicated that 11 study isolates closely matched (94% to 100% profile similarity) reference human clinical and fecal isolates. These findings imply what probably is a low but non-zero risk to humans from environmental and animal source E. coli isolates, especially those from specific human-associated animal species. IMPORTANCE Our detection of potentially pathogenic strains that may pose a health threat to humans among E. coli isolates from surface waters and wild and domesticated animals suggests a need for heightened attention to these reservoirs as possible sources for human acquisition of disease-causing E. coli. Although cats, dogs, and turkeys were especially high-prevalence sources, the presence of such strains in other animal species and at all sampled water sites suggests that this potential risk may be widespread.

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Isolation and Characterization of Escherichia coli Recovered from Maryland Apple Cider and the Cider Production Environment

Journal of Food Protection ◽

10.4315/0362-028x-66.12.2237 ◽

2003 ◽

Vol 66 (12) ◽

pp. 2237-2244 ◽

Cited By ~ 6

Author(s):

I. ARTHUR SENKEL ◽

BEVERLY JOLBITADO ◽

YIFAN ZHANG ◽

DAVID G. WHITE ◽

SHERRY AYERS ◽

...

Keyword(s):

Escherichia Coli ◽

Antimicrobial Susceptibility ◽

Antimicrobial Agents ◽

Fecal Coliforms ◽

Pfge Type ◽

Production Environment ◽

Apple Cider ◽

E Coli ◽

Isolation And Characterization ◽

Potential Contributor

Contaminated apple cider has been implicated in several Escherichia coli O157:H7 outbreaks. In an attempt to investigate sources and modes of entry of E. coli into apple cider, samples of fresh apple, pomace, and cider and equipment and mill floor swabs were analyzed for standard plate counts (SPC), total coliforms (TC), fecal coliforms (FC), and E. coli. E. coli was isolated from 14 (33%) of 42 samples of bottled fresh cider, from food equipment in 6 (67%) of 9 mills, and from apples, pomace, or cider in 7 (78%) of 9 mills. Seventy-five E. coli isolates were further characterized for Shiga toxin–producing E. coli (STEC)–associated virulence factors, antimicrobial susceptibility, and pulsed-field gel electrophoresis (PFGE) type. No E. coli O157:H7 or other STEC was identified. Serotyping and PFGE revealed 64 distinct profiles, suggesting that recovered E. coli arose from multiple independent sources. However, on one occasion, E. coli isolated from the source apple sample was closely related to the E. coli identified in the finished cider sample. E. coli isolates were further tested for antimicrobial susceptibility to 17 antimicrobial agents of human and veterinary importance. Fourteen (19%) of the 75 isolates were resistant to at least one of the antimicrobial agents tested, and 9 (12%) were resistant to at least two of these agents. Of the resistant isolates recovered, 64% were resistant to tetracycline and 57% were resistant to streptomycin. Overall, the level of E. coli contamination in source apple samples did not differ significantly from those in samples of pomace, cider at the press, and cider entering the bottling tank; therefore, source apples cannot be dismissed as a potential contributor of E. coli to the cider-making process.

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First report of Escherichia coli O157 among Iraqi children

Eastern Mediterranean Health Journal ◽

10.26719/2003.9.1-2.159 ◽

2003 ◽

Vol 9 (1-2) ◽

pp. 159-166

Author(s):

Z. A. Shebib ◽

Z. G. Abdul Ghani ◽

L. Kh. Mahdi

Keyword(s):

Escherichia Coli ◽

Nalidixic Acid ◽

Entamoeba Histolytica ◽

Giardia Lamblia ◽

Antimicrobial Agents ◽

Polymyxin B ◽

Bloody Diarrhoea ◽

Escherichia Coli O157 ◽

E Coli ◽

Enterohaemorrhagic Escherichia Coli

We determined the prevalence of enterohaemorrhagic Escherichia coli, especially E. coli O157, and other enteropathogens among 200 children with bloody diarrhoea and 100 age-matched controls at two Baghdad hospitals. Bacterial and parasitic agents were found in 39.5% and 28.5% of cases, respectively; no pathogen was detected in 32%. E. coli O157 was identified in 11.5% and more than one pathogen was found in 15.5% of cases. The most common pathogens were enteropathogenic E. coli [EPEC] [5%] ; E. coli other than E. coli O157 or EPEC [15%] ; Entamoeba histolytica [25%] and Giardia lamblia [3.5%]. All isolates of E. coli O157: H7 were sensitive to cephalexin, ciprofloxacin, gentamicin and nalidixic acid and resistant to erythromycin, polymyxin B and vancomycin. Resistance to 6 or more antimicrobial agents was common [50% of isolates]

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Determination of Escherichia coli Contamination with Chromocult Coliform Agar Showed a High Level of Discrimination Efficiency for Differing Fecal Pollution Levels in Tropical Waters of Kampala, Uganda

Applied and Environmental Microbiology ◽

10.1128/aem.66.2.864-868.2000 ◽

2000 ◽

Vol 66 (2) ◽

pp. 864-868 ◽

Cited By ~ 58

Author(s):

Dennis Byamukama ◽

Frank Kansiime ◽

Robert L. Mach ◽

Andreas H. Farnleitner

Keyword(s):

Escherichia Coli ◽

Surface Waters ◽

Fecal Pollution ◽

Fecal Coliforms ◽

E Coli ◽

Pollution Levels ◽

Lower Ability ◽

Polluted Sites ◽

High Level

ABSTRACT Escherichia coli, total coliforms, fecal coliforms, and sulfite-reducing anaerobic spore formers from different polluted sites in a tropical environment were determined in order to test for their indication ability for fecal contamination. Quantification of E. coli contamination with Chromocult coliform agar proved to be efficient and feasible for determining fecal pollutions in the investigated area within 24 h. The other microbial parameters showed a lower ability to differentiate sites and cannot be recommended for monitoring fecal pollution in the studied tropical surface waters.

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