scholarly journals Genetic Diversity among Escherichia coliIsolates Carrying f18 Genes from Pigs with Porcine Postweaning Diarrhea and Edema Disease

1999 ◽  
Vol 37 (5) ◽  
pp. 1642-1645 ◽  
Author(s):  
Béla Nagy ◽  
Richard A. Wilson ◽  
Thomas S. Whittam
Keyword(s):  
Escherichia Coli ◽  
Dna Hybridization ◽  
Virulence Genes ◽  
Allelic Variation ◽  
Genomic Diversity ◽  
Enzyme Electrophoresis ◽  
Edema Disease ◽  
E Coli ◽  
Multilocus Enzyme Electrophoresis ◽  
Postweaning Diarrhea

Multilocus enzyme electrophoresis was applied to detect allelic variation and multilocus genotypes (electrophoretic types [ETs]) among 43 Escherichia coli isolates from weaned pigs suffering from edema disease or from diarrhea. ETs were analyzed in relation to O serogroups and virulence genes (sta,stb, lt, stx 2, andf18) by DNA hybridization. Genomic diversity was the lowest in serogroup O138, while virulence genes (stx 2and f18) were the most uniform in serogroup O139. In general, the serogroups or toxin and F18 fimbria types were not related to selected ETs, suggesting that the toxin and f18 fimbria genes in E. coli isolates from pigs with postweaning diarrhea or edema disease occur in a variety of chromosomal backgrounds.

scholarly journals Afa, a Diffuse Adherence Fibrillar Adhesin Associated with Enteropathogenic Escherichia coli

2002 ◽  
Vol 70 (5) ◽  
pp. 2681-2689 ◽  
Author(s):  
Rogéria Keller ◽  
Juana G. Ordoñez ◽  
Rosana R. de Oliveira ◽  
Luiz R. Trabulsi ◽  
Thomas J. Baldwin ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Virulence Genes ◽  
Chromosomal Region ◽  
Enzyme Electrophoresis ◽  
Enteropathogenic Escherichia Coli ◽  
Epec Strain ◽  
Infantile Diarrhea ◽  
E Coli ◽  
Multilocus Enzyme Electrophoresis ◽  
Typical Epec

ABSTRACT O55 is one of the most frequent enteropathogenic Escherichia coli (EPEC) O serogroups implicated in infantile diarrhea in developing countries. Multilocus enzyme electrophoresis analysis showed that this serogroup includes two major electrophoretic types (ET), designated ET1 and ET5. ET1 corresponds to typical EPEC, whilst ET5 comprises strains with different combinations of virulence genes, including those for localized adherence (LA) and diffuse adherence (DA). Here we report that ET5 DA strains possess a DA adhesin, designated EPEC Afa. An 11.6-kb chromosomal region including the DA adhesin operon from one O55:H− ET5 EPEC strain was sequenced and found to encode a protein with 98% identity to AfaE-1, an adhesin associated with uropathogenic E. coli. Although described as an afimbrial adhesin, we show that both AfaE-1 and EPEC Afa possess fine fibrillar structures. This is the first characterization and demonstration of an Afa adhesin associated with EPEC.

scholarly journals The AIDA Autotransporter System Is Associated with F18 and Stx2e in Escherichia coli Isolates from Pigs Diagnosed with Edema Disease and Postweaning Diarrhea

2001 ◽  
Vol 8 (1) ◽  
pp. 143-149 ◽  
Author(s):  
Ulla Niewerth ◽  
Andreas Frey ◽  
Thomas Voss ◽  
Chantal Le Bouguénec ◽  
Georg Baljer ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Western Blot ◽  
Virulence Factors ◽  
Rapid Screening ◽  
Edema Disease ◽  
E Coli ◽  
Large Numbers ◽  
High Prevalence ◽  
Pcr Method ◽  
Postweaning Diarrhea

ABSTRACT Pathogenic Escherichia coli strains are known to cause edema disease (ED) and postweaning diarrhea (PWD) in piglets. Although the exact mechanisms of pathogenicity that lead to ED-PWD remain to be elucidated, E. coli-borne Shiga-like toxin and adhesion-mediating virulence factors such as F18 adhesin or F4 fimbriae are believed to play a central role in ED-PWD. In light of these observations we investigated whether another E. coliadhesin, the plasmid-encoded AIDA (adhesin involved in diffuse adherence) might also be present in ED-PWD-causing E. coli isolates. For rapid screening for the AIDA system in large numbers of isolates, a multiplex PCR method along with a duplex Western blot procedure was developed. When screening 104 strains obtained from pigs with or without ED-PWD, we observed a high prevalence of the AIDA operon in porcine E. coli isolates, with over 25% of all strains being AIDA positive, and we could demonstrate a significant association of the intact AIDA gene (orfB) with ED-PWD, while defects in orfB were associated with the absence of disease. Although our data hint toward a contribution of AIDA to ED-PWD, further studies will be necessary since the presence of the AIDA genes was also associated with the presence of the Shiga-like toxin and F18 adhesin genes, two reported virulence factors for ED-PWD.

scholarly journals Prevalence of a Gene Encoding Adhesin Involved in Diffuse Adherence among Escherichia Coli Isolates in Pigs with Postweaning Diarrhea or Edema Disease

2003 ◽  
Vol 15 (4) ◽  
pp. 378-381 ◽  
Author(s):  
Seung-Kwon Ha ◽  
Changsun Choi ◽  
Chanhee Chae
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Coli Strain ◽  
Isolation Rate ◽  
Gene Encoding ◽  
Edema Disease ◽  
E Coli ◽  
Heat Stable ◽  
Fimbrial Adhesins ◽  
Postweaning Diarrhea

A total of 604 Escherichia coli strains isolated from weaned pigs with diarrhea or edema disease on 653 swine farms were screened for the presence of the adhesin involved in diffuse adherence (AIDA) gene by polymerase chain reaction (PCR). Escherichia coli isolates that carried AIDA genes were also tested by PCR for the detection of 5 fimbriae (F4, F5, F6, F18, and F41), 3 heat-stable (STa, STb, and EAST1) and 1 heat-labile (LT) enterotoxin, and Shiga toxin 2e (Stx2e) genes. Forty-five (7.5%) of the 604 E. coli isolates carried the gene for AIDA. Of these 45 isolates, 5 (11.1%) carried EAST1 genes only, 1 (2.2%) carried genes for at least one of the fimbrial adhesins, 12 (26.7%) carried genes for at least one of the toxins, and 27 (60%) carried genes for at least one of the fimbrial adhesins and toxins. Fifty-one percent of strains that carried AIDA genes carried Stx2e genes, and 40% of strains that carried AIDA genes carried F18ab. The isolation rate of enterotoxigenic E. coli strain carrying genes for AIDA was 87%, and the isolation rate of Shiga toxin-producing E. coli strain carrying genes for AIDA was 49%. AIDA may represent an important virulence determinant in pigs with postweaning diarrhea or edema disease.

scholarly journals Genomic Insights of Multidrug-Resistant Escherichia coli From Wastewater Sources and Their Association With Clinical Pathogens in South Africa

2021 ◽  
Vol 8 ◽  
Author(s):  
Joshua Mbanga ◽  
Daniel G. Amoako ◽  
Akebe L. K. Abia ◽  
Mushal Allam ◽  
Arshad Ismail ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Virulence Genes ◽  
Treatment Plant ◽  
Multidrug Resistant ◽  
Genomic Diversity ◽  
Health Concern ◽  
Comparative Genomic ◽  
Phylogenomic Analysis ◽  
E Coli ◽  
Wwtp Effluent

There is limited information on the comparative genomic diversity of antibiotic-resistant Escherichia coli from wastewater. We sought to characterize environmental E. coli isolates belonging to various pathotypes obtained from a wastewater treatment plant (WWTP) and its receiving waters using whole-genome sequencing (WGS) and an array of bioinformatics tools to elucidate the resistomes, virulomes, mobilomes, clonality, and phylogenies. Twelve multidrug-resistant (MDR) diarrheagenic E. coli isolates were obtained from the final effluent of a WWTP, and the receiving river upstream and downstream of the WWTP were sequenced on an Illumina MiSeq machine. The multilocus sequence typing (MLST) analysis revealed that multiple sequence types (STs), the most common of which was ST69 (n = 4) and ST10 (n = 2), followed by singletons belonging to ST372, ST101, ST569, ST218, and ST200. One isolate was assigned to a novel ST ST11351. A total of 66.7% isolates were positive for β-lactamase genes with 58.3% harboring the blaTEM1B gene and a single isolate the blaCTX−M−14 and blaCTX−M−55 extended-spectrum β-lactamase (ESBL) genes. One isolate was positive for the mcr-9 mobilized colistin resistance gene. Most antibiotic resistance genes (ARGs) were associated with mobile genetic support: class 1 integrons (In22, In54, In191, and In369), insertion sequences (ISs), and/or transposons (Tn402 or Tn21). A total of 31 virulence genes were identified across the study isolates, including those responsible for adhesion (lpfA, iha, and aggR), immunity (air, gad, and iss), and toxins (senB, vat, astA, and sat). The virulence genes were mostly associated with IS (IS1, IS3, IS91, IS66, IS630, and IS481) or prophages. Co-resistance to heavy metal/biocide, antibiotics were evident in several isolates. The phylogenomic analysis with South African E. coli isolates from different sources (animals, birds, and humans) revealed that isolates from this study mostly clustered with clinical isolates. Phylogenetics linked with metadata revealed that isolates did not cluster according to source but according to ST. The occurrence of pathogenic and MDR isolates in the WWTP effluent and the associated river is a public health concern.

scholarly journals Molecular Characterization of a Serotype O121:H19 Clone, a Distinct Shiga Toxin-Producing Clone of Pathogenic Escherichia coli

2002 ◽  
Vol 70 (12) ◽  
pp. 6853-6859 ◽  
Author(s):  
Cheryl L. Tarr ◽  
Teresa M. Large ◽  
Chris L. Moeller ◽  
David W. Lacher ◽  
Phillip I. Tarr ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Allelic Variation ◽  
Virulence Gene ◽  
Gene Profiling ◽  
Enzyme Electrophoresis ◽  
Sequencing Analysis ◽  
Chromosomal Dna ◽  
Waterborne Outbreak ◽  
E Coli

ABSTRACT Most illnesses caused by Shiga toxin-producing Escherichia coli (STEC) have been attributed to E. coli serotype O157:H7, but non-O157 STEC infections are now increasingly recognized as public health problems worldwide. The O121:H19 serotype is being isolated more frequently from clinical specimens and has been implicated in one waterborne outbreak. We used multilocus virulence gene profiling, a PCR-based assay, to characterize the virulence gene content of 24 isolates of serotype O121:H19 and nonmotile variants. We also performed multilocus enzyme electrophoresis and multilocus sequencing to establish the clonal relatedness of O121 isolates and to elucidate the relationship of O121 to common STEC clones. The 24 isolates were found to represent a single bacterial clone, as there was no allelic variation across 18 enzyme loci among the isolates. The complete nucleotide sequence of the intimin gene differed by four substitutions from that of the epsilon (Int-ε) allele of O103:H2 strain PMK5. The typical O121 virulence gene profile was similar to the profiles of enterohemorrhagic E. coli (EHEC) clones of E. coli: it included a Shiga toxin 2 gene (stx 2), two genes on the EHEC plasmid (toxB and ehxA), and the gene encoding intimin (eae). Despite the similarities, putative virulence genes distributed on O islands—large chromosomal DNA segments present in the O157:H7 genome—were useful for discriminating among STEC serotypes and the O121:H19 clone had a composite profile that was distinct from the profiles of the other major EHEC clones of pathogenic E. coli. On the basis of sequencing analysis with 13 housekeeping genes, the O121:H19 clone did not fall into any of the four classical EHEC and enteropathogenic E. coli groups but instead was closely related to two eae-negative STEC strains.

scholarly journals DNA Microarray-Based Identification of Serogroups and Virulence Gene Patterns of Escherichia coli Isolates Associated with Porcine Postweaning Diarrhea and Edema Disease

2007 ◽  
Vol 73 (12) ◽  
pp. 4082-4088 ◽  
Author(s):  
Weiqing Han ◽  
Bin Liu ◽  
Boyang Cao ◽  
Lothar Beutin ◽  
Ulrike Kr�ger ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Dna Microarray ◽  
Bacterial Species ◽  
Virulence Gene ◽  
Detection Sensitivity ◽  
Edema Disease ◽  
E Coli ◽  
Postweaning Diarrhea ◽  
Porcine Feces ◽  
Reference Strains

ABSTRACT Escherichia coli strains causing postweaning diarrhea (PWD) and edema disease (ED) in pigs are limited to a number of serogroups, with O8, O45, O138, O139, O141, O147, O149, and O157 being the most commonly reported worldwide. In this study, a DNA microarray based on the O-antigen-specific genes of all 8 E. coli serogroups, as well as 11 genes encoding adhesion factors and exotoxins associated with PWD and ED, was developed for the identification of related serogroups and virulence gene patterns. The microarray method was tested against 186 E. coli and Shigella O-serogroup reference strains, 13 E. coli reference strains for virulence markers, 43 E. coli clinical isolates, and 12 strains of other bacterial species and shown to be highly specific with reproducible results. The detection sensitivity was 0.1 ng of genomic DNA or 103 CFU per 0.3 g of porcine feces in mock samples. Seventeen porcine feces samples from local hoggeries were examined using the microarray, and the result for one sample was verified by the conventional serotyping methods. This microarray can be readily used to screen for the presence of PWD- and ED-associated E. coli in porcine feces samples.

scholarly journals Comparative Analysis of Virulence Genes, Genetic Diversity, and Phylogeny of Commensal and Enterotoxigenic Escherichia coli Isolates from Weaned Pigs

2006 ◽  
Vol 73 (1) ◽  
pp. 83-91 ◽  
Author(s):  
Xi-Yang Wu ◽  
Toni Chapman ◽  
Darren J. Trott ◽  
Karl Bettelheim ◽  
Thuy N. Do ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Clustering Analysis ◽  
Virulence Genes ◽  
Geographical Origin ◽  
Virulence Gene ◽  
Dna Fingerprint ◽  
Enterotoxigenic Escherichia Coli ◽  
Pathogenicity Islands ◽  
E Coli ◽  
Postweaning Diarrhea

ABSTRACT If the acquisition of virulence genes (VGs) for pathogenicity were not solely acquired through horizontal gene transfers of pathogenicity islands, transposons, and phages, then clonal clusters of enterotoxigenic Escherichia coli (ETEC) would contain few or even none of the VGs found in strains responsible for extraintestinal infections. To evaluate this possibility, 47 postweaning diarrhea (PWD) ETEC strains from different geographical origins and 158 commensal E. coli isolates from the gastrointestinal tracts of eight group-housed healthy pigs were screened for 36 extraintestinal and 18 enteric VGs using multiplex PCR assays. Of 36 extraintestinal VGs, only 8 were detected (fimH, traT, fyuA, hlyA, kpsMtII, k5, iha, and ompT) in the ETEC collection. Among these, hlyA (α-hemolysin) and iha (nonhemagglutinating adhesin) occurred significantly more frequently among the ETEC isolates than in the commensal isolates. Clustering analysis based on the VG profiles separated commensal and ETEC isolates and even differentiated serogroup O141 from O149. On the other hand, pulsed-field gel electrophoresis (PFGE) successfully clustered ETEC isolates according to both serotype and geographical origin. In contrast, the commensal isolates were heterogeneous with respect to both serotype and DNA fingerprint. This study has validated the use of VG profiling to examine pathogenic relationships between porcine ETEC isolates. The clonal relationships of these isolates can be further clarified by PFGE fingerprinting. The presence of extraintestinal VGs in porcine ETEC confirmed the hypothesis that individual virulence gene acquisitions can occur concurrently against a background of horizontal gene transfers of pathogenicity islands. Over time, this could enable specific clonotypes to respond to host selection pressure and to evolve into new strains with increased virulence.

scholarly journals Comparison of Genotypes of Escherichia Coli Strains Carrying F18ab and F18ac Fimbriae from Pigs

2009 ◽  
Vol 21 (3) ◽  
pp. 359-364 ◽  
Author(s):  
Chitrita DebRoy ◽  
Elisabeth Roberts ◽  
William Scheuchenzuber ◽  
Subhashinie Kariyawasam ◽  
Bhushan M. Jayarao
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Protein Sequences ◽  
Gene Encoding ◽  
Shiga Toxins ◽  
Edema Disease ◽  
E Coli ◽  
First Time ◽  
Postweaning Diarrhea ◽  
Current Report

Escherichia coli carrying the F18 fimbriae colonize the small intestine of pigs and cause postweaning diarrhea and edema disease. There are 2 closely related antigenic variants of F18, F18ab, and F18ac. While F18ab-positive strains are known to be associated with edema disease, E. coli–carrying F18ac are known to cause diarrhea. One hundred ninety-eight E. coli isolates obtained from cases of diarrhea and edema disease in pigs isolated from feces or intestine were screened for the presence of the fedA gene encoding for F18 fimbriae. To distinguish between F18ab and F18ac, the fedA gene was sequenced in 69 F18-positive isolates/strains. The translated protein sequences of the fedA gene in the 2 variants differ; F18ac protein carries proline at amino acid residue 121, which is substituted or missing in F18ab. The F18ab- and F18ac-positive E. coli strains were compared for the presence of virulence attributes, serotypes of the isolates, and relatedness between the strains. Contrary to earlier reports that E. coli F18ab-positive strains mostly express Shiga toxin and F18ac-positive strains generally express enterotoxins, the current report shows conclusively for the first time that both variant types may carry genes for Shiga toxins and/or enterotoxins. Monoclonal antibodies produced against F18ab or F18ac fimbriae could not distinguish the strains carrying the 2 variants. Therefore, it was concluded that either of the 2 F18 variants, F18ab or F18ac, may be involved in causing postweaning diarrhea or edema disease in pigs.

scholarly journals Phylogenetic Analysis of Enteroaggregative and Diffusely Adherent Escherichia coli

1999 ◽  
Vol 67 (6) ◽  
pp. 2692-2699 ◽  
Author(s):  
John R. Czeczulin ◽  
Thomas S. Whittam ◽  
Ian R. Henderson ◽  
Fernando Navarro-Garcia ◽  
James P. Nataro
Keyword(s):  
Escherichia Coli ◽  
Allelic Variation ◽  
Housekeeping Genes ◽  
Prototype Strain ◽  
Transfer Model ◽  
Enzyme Electrophoresis ◽  
E Coli ◽  
Virulence Plasmids ◽  
Chromosomal Markers

ABSTRACT The phylogenetics of the various pathotypes of diarrheagenicEscherichia coli are not completely understood. In this study, we identified several plasmid and chromosomal genes in the pathogenic enteroaggregative E. coli (EAEC) prototype strain 042 and determined the prevalence of these loci among EAEC and diffusely adherent E. coli strains. The distribution of these genes is analyzed within an evolutionary framework provided by the characterization of allelic variation in housekeeping genes via multilocus enzyme electrophoresis. Our data reveal that EAEC strains are heterogeneous with respect to chromosomal and plasmid-borne genes but that the majority harbor a member of a conserved family of virulence plasmids. Comparison of plasmid and chromosomal relatedness of strains suggests clonality of chromosomal markers and a limited transfer model of plasmid distribution.

scholarly journals Presence of β-Lactamase-producing Enterobacterales and Salmonella Isolates in Marine Mammals

2021 ◽  
Vol 22 (11) ◽  
pp. 5905
Author(s):  
Olivia M. Grünzweil ◽  
Lauren Palmer ◽  
Adriana Cabal ◽  
Michael P. Szostak ◽  
Werner Ruppitsch ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Marine Mammals ◽  
Virulence Genes ◽  
Multidrug Resistant ◽  
Healthcare Sector ◽  
Whole Genome ◽  
E Coli ◽  
High Prevalence ◽  
Lactamase Gene ◽  
Sequence Types

Marine mammals have been described as sentinels of the health of marine ecosystems. Therefore, the aim of this study was to investigate (i) the presence of extended-spectrum β-lactamase (ESBL)- and AmpC-producing Enterobacterales, which comprise several bacterial families important to the healthcare sector, as well as (ii) the presence of Salmonella in these coastal animals. The antimicrobial resistance pheno- and genotypes, as well as biocide susceptibility of Enterobacterales isolated from stranded marine mammals, were determined prior to their rehabilitation. All E. coli isolates (n = 27) were screened for virulence genes via DNA-based microarray, and twelve selected E. coli isolates were analyzed by whole-genome sequencing. Seventy-one percent of the Enterobacterales isolates exhibited a multidrug-resistant (MDR) pheno- and genotype. The gene blaCMY (n = 51) was the predominant β-lactamase gene. In addition, blaTEM-1 (n = 38), blaSHV-33 (n = 8), blaCTX-M-15 (n = 7), blaOXA-1 (n = 7), blaSHV-11 (n = 3), and blaDHA-1 (n = 2) were detected. The most prevalent non-β-lactamase genes were sul2 (n = 38), strA (n = 34), strB (n = 34), and tet(A) (n = 34). Escherichia coli isolates belonging to the pandemic sequence types (STs) ST38, ST167, and ST648 were identified. Among Salmonella isolates (n = 18), S. Havana was the most prevalent serotype. The present study revealed a high prevalence of MDR bacteria and the presence of pandemic high-risk clones, both of which are indicators of anthropogenic antimicrobial pollution, in marine mammals.

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