scholarly journals Virulence Genes and Molecular Typing of Different Groups of Escherichia coli O157 Strains in Cattle

2009 ◽  
Vol 75 (19) ◽  
pp. 6282-6291 ◽  
Author(s):  
István Tóth ◽  
Herbert Schmidt ◽  
Gábor Kardos ◽  
Zsuzsanna Lancz ◽  
Kristina Creuzburg ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Virulence Genes ◽  
Housekeeping Genes ◽  
Enzyme Analysis ◽  
Virulence Plasmid ◽  
O157 Strain ◽  
Pathogenic Potential ◽  
E Coli ◽  
Strain Collection ◽  
Genes Encoding

ABSTRACT Characterization of an Escherichia coli O157 strain collection (n = 42) derived from healthy Hungarian cattle revealed the existence of diverse pathotypes. Enteropathogenic E. coli (EPEC; eae positive) appeared to be the most frequent pathotype (n = 22 strains), 11 O157 strains were typical enterohemorrhagic E. coli (EHEC; stx and eae positive), and 9 O157 strains were atypical, with none of the key stx and eae virulence genes detected. EHEC and EPEC O157 strains all carried eae-gamma, tir-gamma, tccP, and paa. Other virulence genes located on the pO157 virulence plasmid and different O islands (O island 43 [OI-43] and OI-122), as well as espJ and espM, also characterized the EPEC and EHEC O157 strains with similar frequencies. However, none of these virulence genes were detected by PCR in atypical O157 strains. Interestingly, five of nine atypical O157 strains produced cytolethal distending toxin V (CDT-V) and carried genes encoding long polar fimbriae. Macro-restriction fragment enzyme analysis (pulsed-field gel electrophoresis) revealed that these E. coli O157 strains belong to four main clusters. Multilocus sequence typing analysis revealed that five housekeeping genes were identical in EHEC and EPEC O157 strains but were different in the atypical O157 strains. These results suggest that the Hungarian bovine E. coli O157 strains represent at least two main clones: EHEC/EPEC O157:H7/NM (nonmotile) and atypical CDT-V-producing O157 strains with H antigens different from H7. The CDT-V-producing O157 strains represent a novel genogroup. The pathogenic potential of these strains remains to be elucidated.

Virulence factors analysis and antibiotic resistance of uropathogenic Escherichia coli isolated from patients in northeast of Iran

2020 ◽  
Author(s):  
Mahdis Ghavidel ◽  
Tahere Gholamhosseini-Moghadam ◽  
Kimiya Nourian ◽  
Kiarash Ghazvini
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Virulence Genes ◽  
High Rate ◽  
Resistance Pattern ◽  
Antibiotics Resistance ◽  
Disk Diffusion Test ◽  
E Coli ◽  
Genes Encoding ◽  
Tract Infections

Background and Objectives: Escherichia coli is known to be the pathogen commonly isolated from those infected with uri- nary tract infections (UTIs). The aim of this study was to investigate the presence of E. coli virulence genes and antibiotics’ resistance pattern among clinical isolates in the Northeast of Iran. Relationships between virulence genes and antimicrobial resistances were studied as well. Materials and Methods: Three hundred isolates of E. coli were isolated from patients with UTIs that referred to Ghaem and Imam Reza hospitals (Mashhad, Iran) during August 2016 to February 2017. A multiplex PCR was employed to amplify the genes encoding pyelonephritis associated pili (pap), S-family adhesions (sfa), type1fimbriae (fimH) and aerobactin (aer). Disk diffusion test was performed to test the susceptibility of isolates to β-lactams, aminoglycosides, cephalosporins, quino- lone, fluoroquinolones, carbapenems and trimethoprim-sulfamethoxazole. Results: The PCR results identified the fimH in 78.4%, aer in 70.5%, sfa in 13.6% and the pap in 8.2% of isolates. The rates of antibiotic resistance of the isolates were as follows: 64.7% resistant to cephalosporins, 34% to trimethoprim-sul- famethoxazole, 31% to fluoroquinolones, 15.3% to aminoglycosides, 13.3% to β-lactams, 7.8% to quinolones and 4.4% to carbapenems. Significant relationships existed between pap and aer, pap and sfa, aer and fluoroquinolones also pap and cephalosporins. Conclusion: fimH and aer were found in > 50% of isolates suggesting the importance of both genes in UPEC. The majority of isolates had fimH as adhesion factor for colonization. Determining antibiotic resistance patterns in specific geographical areas is necessary for appropriate treatment of urinary tract infection. The high rate of resistance to cephalosporins is most likely due to incorrect drug administration

scholarly journals Isolation and Characterization of Potentially Pathogenic Antimicrobial-Resistant Escherichia coli Strains from Chicken and Pig Farms in Spain

2010 ◽  
Vol 76 (9) ◽  
pp. 2799-2805 ◽  
Author(s):  
Pilar Cortés ◽  
Vanessa Blanc ◽  
Azucena Mora ◽  
Ghizlane Dahbi ◽  
Jesús E. Blanco ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Virulence Genes ◽  
Phylogenetic Analyses ◽  
Virulence Gene ◽  
E Coli ◽  
Isolation And Characterization ◽  
Zoonotic Risk ◽  
Poultry Farms ◽  
Pig Farms ◽  
Genes Encoding

ABSTRACT To ascertain whether on animal farms there reside extended-spectrum β-lactamase (ESBL) and plasmidic class C β-lactamase-producing Escherichia coli isolates potentially pathogenic for humans, phylogenetic analyses, pulsed-field gel electrophoresis (PFGE) typing, serotyping, and virulence genotyping were performed for 86 isolates from poultry (57 isolates) and pig (29 isolates) farms. E. coli isolates from poultry farms carried genes encoding enzymes of the CTX-M-9 group as well as CMY-2, whereas those from pig farms mainly carried genes encoding CTX-M-1 enzymes. Poultry and pig isolates differed significantly in their phylogenetic group assignments, with phylogroup A predominating in pig isolates and phylogroup D predominating in avian isolates. Among the 86 farm isolates, 23 (26.7%) carried two or more virulence genes typical of extraintestinal pathogenic E. coli (ExPEC). Of these, 20 were isolated from poultry farms and only 3 from pig farms. Ten of the 23 isolates belonged to the classic human ExPEC serotypes O2:H6, O2:HNM, O2:H7, O15:H1, and O25:H4. Despite the high diversity of serotypes and pulsotypes detected among the 86 farm isolates, 13 PFGE clusters were identified. Four of these clusters contained isolates with two or more virulence genes, and two clusters exhibited the classic human ExPEC serotypes O2:HNM (ST10) and O2:H6 (ST115). Although O2:HNM and O2:H6 isolates of human and animal origins differed with respect to their virulence genes and PFGE pulsotypes, the O2:HNM isolates from pigs showed the same sequence type (ST10) as those from humans. The single avian O15:H1 isolate was compared with human clinical isolates of this serotype. Although all were found to belong to phylogroup D and shared the same virulence gene profile, they differed in their sequence types (ST362-avian and ST393-human) and PFGE pulsotypes. Noteworthy was the detection, for the first time, in poultry farms of the clonal groups O25b:H4-ST131-B2, producing CTX-M-9, and O25a-ST648-D, producing CTX-M-32. The virulence genes and PFGE profiles of these two groups were very similar to those of clinical human isolates. While further studies are required to determine the true zoonotic potential of these clonal groups, our results emphasize the zoonotic risk posed especially by poultry farms, but also by pig farms, as reservoirs of ESBL- and CMY-2-encoding E. coli.

scholarly journals Pathogenic Potential, Genetic Diversity, and Population Structure of Escherichia coli Strains Isolated from a Forest-Dominated Watershed (Comox Lake) in British Columbia, Canada

2014 ◽  
Vol 81 (5) ◽  
pp. 1788-1798 ◽  
Author(s):  
Abhirosh Chandran ◽  
Asit Mazumder
Keyword(s):  
Escherichia Coli ◽  
Drinking Water ◽  
Population Structure ◽  
Virulence Genes ◽  
Repetitive Element ◽  
Fingerprint Analysis ◽  
Pathogenic Potential ◽  
Content Type ◽  
E Coli ◽  
Heat Stable

ABSTRACTEscherichia coliisolates (n= 658) obtained from drinking water intakes of Comox Lake (2011 to 2013) were screened for the following virulence genes (VGs):stx1andstx2(Shiga toxin-producingE. coli[STEC]),eaeand the adherence factor (EAF) gene (enteropathogenicE. coli[EPEC]), heat-stable (ST) enterotoxin (variants STh and STp) and heat-labile enterotoxin (LT) genes (enterotoxigenicE. coli[ETEC]), andipaH(enteroinvasiveE. coli[EIEC]). The only genes detected wereeaeandstx2, which were carried by 37.69% (n= 248) of the isolates. Onlyeaewas harbored by 26.74% (n= 176) of the isolates, representing potential atypical EPEC strains, while onlystx2was detected in 10.33% (n= 68) of the isolates, indicating potential STEC strains. Moreover, four isolates were positive for both thestx2andeaegenes, representing potential EHEC strains. The prevalence of VGs (eaeorstx2) was significantly (P< 0.0001) higher in the fall season, and multiple genes (eaeplusstx2) were detected only in fall. Repetitive element palindromic PCR (rep-PCR) fingerprint analysis of 658E. coliisolates identified 335 unique fingerprints, with an overall Shannon diversity (H′) index of 3.653. Diversity varied among seasons over the years, with relatively higher diversity during fall. Multivariate analysis of variance (MANOVA) revealed that the majority of the fingerprints showed a tendency to cluster according to year, season, and month. Taken together, the results indicated that the diversity and population structure ofE. colifluctuate on a temporal scale, reflecting the presence of diverse host sources and their behavior over time in the watershed. Furthermore, the occurrence of potentially pathogenicE. colistrains in the drinking water intakes highlights the risk to human health associated with direct and indirect consumption of untreated surface water.

scholarly journals Integrated Genomic Map from Uropathogenic Escherichia coli J96

2000 ◽  
Vol 68 (10) ◽  
pp. 5933-5942 ◽  
Author(s):  
Lyla J. Melkerson-Watson ◽  
Christopher K. Rode ◽  
Lixin Zhang ◽  
Betsy Foxman ◽  
Craig A. Bloch
Keyword(s):  
Escherichia Coli ◽  
Virulence Genes ◽  
Housekeeping Genes ◽  
E Coli ◽  
Restriction Sites ◽  
Physical And Genetic Map ◽  
K 12 ◽  
Genomic Map ◽  
Insertion Mutants

ABSTRACT Escherichia coli J96 is a uropathogen having both broad similarities to and striking differences from nonpathogenic, laboratoryE. coli K-12. Strain J96 contains three large (>100-kb) unique genomic segments integrated on the chromosome; two are recognized as pathogenicity islands containing urovirulence genes. Additionally, the strain possesses a fourth smaller accessory segment of 28 kb and two deletions relative to strain K-12. We report an integrated physical and genetic map of the 5,120-kb J96 genome. The chromosome contains 26 NotI, 13 BlnI, and 7 I-CeuI macrorestriction sites. Macrorestriction mapping was rapidly accomplished by a novel transposon-based procedure: analysis of modified minitransposon insertions served to align the overlapping macrorestriction fragments generated by three different enzymes (each sharing a common cleavage site within the insert), thus integrating the three different digestion patterns and ordering the fragments. The resulting map, generated from a total of 54 mini-Tn10insertions, was supplemented with auxanography and Southern analysis to indicate the positions of insertionally disrupted aminosynthetic genes and cloned virulence genes, respectively. Thus, it contains not only physical, macrorestriction landmarks but also the loci for eight housekeeping genes shared with strain K-12 and eight acknowledged urovirulence genes; the latter confirmed clustering of virulence genes at the large unique accessory chromosomal segments. The 115-kb J96 plasmid was resolved by pulsed-field gel electrophoresis inNotI digests. However, because the plasmid lacks restriction sites for the enzymes BlnI and I-CeuI, it was visualized in BlnI and I-CeuI digests only of derivatives carrying plasmid inserts artificially introducing these sites. Owing to an I-SceI site on the transposon, the plasmid could also be visualized and sized from plasmid insertion mutants after digestion with this enzyme. The insertional strains generated in construction of the integrated genomic map provide useful physical and genetic markers for further characterization of the J96 genome.

scholarly journals Serogroups and virulence genes of Escherichia coli isolated from psittacine birds

2011 ◽  
Vol 31 (10) ◽  
pp. 916-921 ◽  
Author(s):  
Terezinha Knöbl ◽  
André B.S Saidenberg ◽  
Andrea M Moreno ◽  
Tânia A.T Gomes ◽  
Mônica A.M Vieira ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Virulence Factors ◽  
Virulence Genes ◽  
Serum Resistance ◽  
Temperature Sensitive ◽  
E Coli ◽  
Cytotoxic Necrotizing Factor ◽  
Heat Stable ◽  
Genes Encoding ◽  
Cytotoxic Necrotizing Factor 1

Escherichia coli isolates from 24 sick psittacine birds were serogrouped and investigated for the presence of genes encoding the following virulence factors: attaching and effacing (eae), enteropathogenic E. coli EAF plasmid (EAF), pili associated with pyelonephritis (pap), S fimbriae (sfa), afimbrial adhesin (afa), capsule K1 (neu), curli (crl, csgA), temperature-sensitive hemagglutinin (tsh), enteroaggregative heat-stable enterotoxin-1 (astA), heat-stable enterotoxin -1 heat labile (LT) and heat stable (STa and STb) enterotoxins, Shiga-like toxins (stx1 and stx2), cytotoxic necrotizing factor 1 (cnf1), haemolysin (hly), aerobactin production (iuc) and serum resistance (iss). The results showed that the isolates belonged to 12 serogroups: O7; O15; O21; O23; O54; O64; O76; O84; O88; O128; O152 and O166. The virulence genes found were: crl in all isolates, pap in 10 isolates, iss in seven isolates, csgA in five isolates, iuc and tsh in three isolates and eae in two isolates. The combination of virulence genes revealed 11 different genotypic patterns. All strains were negative for genes encoding for EAF, EAEC, K1, sfa, afa, hly, cnf, LT, STa, STb, stx1 and stx2. Our findings showed that some E. coli isolated from psittacine birds present the same virulence factors as avian pathogenic E. coli (APEC), uropathogenic E. coli (UPEC) and Enteropathogenic E. coli (EPEC) pathotypes.

Relationship between eae and stx Virulence Genes and Escherichia coli in an Agricultural Watershed: Implications for Irrigation Water Standards and Leafy Green Commodities†

2011 ◽  
Vol 74 (1) ◽  
pp. 18-23 ◽  
Author(s):  
DANIEL R. SHELTON ◽  
JEFFREY S. KARNS ◽  
CARY COPPOCK ◽  
JITU PATEL ◽  
MANAN SHARMA ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Virulence Genes ◽  
Agricultural Watershed ◽  
Recreational Waters ◽  
Waterborne Pathogen ◽  
E Coli ◽  
Leafy Greens ◽  
Genes Encoding ◽  
Forested Areas ◽  
Irrigation Waters

The California Leafy Greens Marketing Agreement (LGMA) was adopted in an effort to minimize the risk of contamination of leafy greens with enteric pathogens from a variety of sources, including ground and surface irrigation waters. The LGMA contains standards similar to those established for recreational waters, based on Escherichia coli concentrations. However, no correlation between E. coli and any specific waterborne pathogen(s) has been reported. We conducted this monitoring study in an agricultural watershed to (i) evaluate spatial and temporal fluctuations in E. coli populations and virulence genes associated with pathogenic E. coli and (ii) investigate whether a relationship could be established between E. coli and virulence genes. The virulence genes targeted for analysis were the eae and stx genes, encoding for intimin and Shiga-like toxins, respectively; they were detected with PCR methods. E. coli concentrations and eae and stx prevalence varied both spatially and temporally. In general, both were higher in agricultural than in forested areas and were higher in the summer and fall seasons than in winter. The eae and stx genes were prevalent throughout the watershed. However, in the absence of actual isolates, no conclusions could be drawn regarding the prevalence of specific pathogenic E. coli. No correlation was observed between E. coli concentrations and virulence genes; lower E. coli concentrations were not necessarily associated with decreased prevalence of eae and stx genes. These results suggest that the LGMA standards might not adequately address the issue of waterborne contamination, and that alternative criteria might be required.

scholarly journals Evaluating the Pathogenic Potential of Environmental Escherichia coli by Using the Caenorhabditis elegans Infection Model

2013 ◽  
Vol 79 (7) ◽  
pp. 2435-2445 ◽  
Author(s):  
Alexandra Merkx-Jacques ◽  
Anja Coors ◽  
Roland Brousseau ◽  
Luke Masson ◽  
Alberto Mazza ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Caenorhabditis Elegans ◽  
Virulence Genes ◽  
Human Health Risk ◽  
Environmental Isolates ◽  
Pathogenic Potential ◽  
Content Type ◽  
E Coli ◽  
C Elegans ◽  
Infection Assay

ABSTRACTThe detection and abundance ofEscherichia coliin water is used to monitor and mandate the quality of drinking and recreational water. Distinguishing commensal waterborneE. coliisolates from those that cause diarrhea or extraintestinal disease in humans is important for quantifying human health risk. A DNA microarray was used to evaluate the distribution of virulence genes in 148E. colienvironmental isolates from a watershed in eastern Ontario, Canada, and in eight clinical isolates. Their pathogenic potential was evaluated withCaenorhabditis elegans, and the concordance between the bioassay result and the pathotype deduced by genotyping was explored. Isolates identified as potentially pathogenic on the basis of their complement of virulence genes were significantly more likely to be pathogenic toC. elegansthan those determined to be potentially nonpathogenic. A number of isolates that were identified as nonpathogenic on the basis of genotyping were pathogenic in the infection assay, suggesting that genotyping did not capture all potentially pathogenic types. The detection of the adhesin-encoding genessfaD,focA, andfocG, which encode adhesins; ofiroN2, which encodes a siderophore receptor; ofpic, which encodes an autotransporter protein; and ofb1432, which encodes a putative transposase, was significantly associated with pathogenicity in the infection assay. Overall,E. coliisolates predicted to be pathogenic on the basis of genotyping were indeed so in theC. elegansinfection assay. Furthermore, the detection ofC. elegans-infective environmental isolates predicted to be nonpathogenic on the basis of genotyping suggests that there are hitherto-unrecognized virulence factors or combinations thereof that are important in the establishment of infection.

scholarly journals Diverse Escherichia coli pathovars of phylogroups B2 and D isolated from animals in Tunisia

2017 ◽  
Vol 11 (07) ◽  
pp. 549-556 ◽  
Author(s):  
Hajer Kilani ◽  
Mohamed Salah Abbassi ◽  
Sana Ferjani ◽  
Rakia Ben Salem ◽  
Riadh Mansouri ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Polymerase Chain Reaction ◽  
Antibiotic Resistance ◽  
Virulence Genes ◽  
Chain Reaction ◽  
E Coli ◽  
Class 1 ◽  
Genes Encoding ◽  
Polymerase Chain ◽  
Relationship Of

Introduction: The virulent Escherichia coli strains responsible for extraintestinal infections were mainly belonged to B2 and D phylogroups. However, no past studies have determinate via the presence of virulence genes the frequency of E. coli pathovars recovered from animals housed in farms in Tunisia. The aims of this study were to investigate 26 E. coli isolated from healthy and diarrheic animals and to determinate via the presence of virulence genes the frequency of pathovars. Methodology: Twenty-six E. coli isolates of phylogroups B2 (n = 14), B22 (n = 9), B23 (n = 5), and D2 (n = 12) were characterized. Genes encoding virulence factors (fimH,eaeA,aggC,papC, papG allele III, hlyA, east1, cnf1, exhA,stx1, stx2, iutA, fyuA, ibeA,and ipaH), and antibiotic resistance as well as class 1 and 2 integrons were searched by polymerase chain reaction (PCR). The genetic relationship of isolates was done by PFGE. Results: According to the occurrence of specific genes the 26 isolates were classified as:9 EAEC, 2 EHEC, 4 UPEC, 3 EPEC/EHEC and 1 NTEC. Therefore, 2 Ex-PEC and 5 APEC were presented amongst our strains. Some isolates (12) were clonal and the remaining was unrelated. Conclusions: Higher diversity of pathovars which carried diverse combinations of virulence genes in healthy isolates. In addition, it seems that the infections were caused by different mechanisms.

scholarly journals Patterns of Variations in Escherichia coli Strains That Produce Cytolethal Distending Toxin

2004 ◽  
Vol 72 (2) ◽  
pp. 684-690 ◽  
Author(s):  
Carol L. Pickett ◽  
Robert B. Lee ◽  
Aysegul Eyigor ◽  
Ben Elitzur ◽  
Emily M. Fox ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Virulence Genes ◽  
Pcr Primers ◽  
Pcr Analysis ◽  
Cytolethal Distending Toxin ◽  
E Coli ◽  
Heat Stable ◽  
Genes Encoding ◽  
Factor Type

ABSTRACT A collection of 20 Escherichia coli strains that produce cytolethal distending toxin (CDT) were analyzed for their virulence-associated genes. All of these strains were serotyped, and multiplex PCR analysis was used to ascertain the presence of genes encoding other virulence factors, including Shiga toxin, intimin, enterohemolysin, cytotoxic necrotizing factor type 1 (CNF1) and CNF2, heat-stable toxin, and heat-labile toxin. These CDT-producing strains possessed various combinations of known virulence genes, some of which have not been noted before. Partial cdtB sequences were obtained from 10 of these strains, and their predicted CdtB sequences were compared to known E. coli CdtB sequences; some of the sequences were identical to known CdtB sequences, but two were not. PCR primers based on sequence differences between the known cdt sequences were tested for their ability to detect CDT producers and to determine CDT type. Correlations between the type of CDT produced, the presence of other virulence properties, and overall strain relatedness revealed that the CDT producers studied here can be divided into three general groups, with distinct differences in CDT type and in their complement of virulence-associated genes.

DNA Microarray-Based Genomic Characterization of the Pathotypes of Escherichia coli O26, O45, O103, O111, and O145 Isolated from Feces of Feedlot Cattle†

2019 ◽  
Vol 82 (3) ◽  
pp. 395-404 ◽  
Author(s):  
PRAGATHI B. SHRIDHAR ◽  
ISHA R. PATEL ◽  
JAYANTHI GANGIREDLA ◽  
LANCE W. NOLL ◽  
XIAORONG SHI ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Dna Microarray ◽  
Virulence Genes ◽  
Feedlot Cattle ◽  
Clinical Strains ◽  
E Coli ◽  
Type Iii ◽  
Virulence Potential ◽  
Genes Encoding ◽  
Secretory System

ABSTRACT Shiga toxin–producing Escherichia coli (STEC) serogroups O26, O45, O103, O111, O121, and O145, referred to as the top six non-O157 serogroups, are responsible for more than 70% of human non-O157 STEC infections in North America. Cattle harbor non-O157 strains in the hindgut and shed them in the feces. The objective of this study was to use the U.S. Food and Drug Administration (FDA) E. coli identification (ECID) DNA microarray to identify the serotype, assess the virulence potential of each, and determine the phylogenetic relationships among five of the six non-O157 E. coli serogroups isolated from feedlot cattle feces. Forty-four strains of STEC, enterohemorrhagic E. coli (EHEC), enteropathogenic E. coli (EPEC), or putative nonpathotype E. coli (NPEC) of cattle origin and five human clinical strains of EHEC were assayed with the FDA-ECID DNA microarray. The cattle strains harbored diverse flagellar genes. The bovine and human strains belonging to serogroups O26, O45, and O103 carried stx1 only, O111 carried both stx1 and stx2, and O145 carried either stx1 or stx2. The strains were also positive for various subtypes of intimin and other adhesins (IrgA homologue adhesin, long polar fimbriae, mannose-specific adhesin, and curli). Both human and cattle strains were positive for LEE-encoded type III secretory system genes and non–LEE-encoded effector genes. SplitsTree4, a program used to determine the phylogenetic relationship among the strains, revealed that the strains within each serogroup clustered according to their pathotype. In addition to genes encoding Shiga toxins, bovine non-O157 E. coli strains possessed other major virulence genes, including those for adhesins, type III secretory system proteins, and plasmid-borne virulence genes, similar to human clinical strains. Because virulence factors encoded by these genes are involved in the pathogenesis of various pathotypes of E. coli, the bovine non-O157 strains could cause human illness. The FDA-ECID DNA microarray assay rapidly provided a profile of the virulence genes for assessment of the virulence potential of each strain.

Sign in / Sign up

Export Citation Format

Share Document