scholarly journals Serotypes and Virulence Gene Profiles of Shiga Toxin-Producing Escherichia coli Strains Isolated from Feces of Pasture-Fed and Lot-Fed Sheep

2004 ◽  
Vol 70 (7) ◽  
pp. 3910-3917 ◽  
Author(s):  
Steven P. Djordjevic ◽  
Vidiya Ramachandran ◽  
Karl A. Bettelheim ◽  
Barbara A. Vanselow ◽  
Peter Holst ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Virulence Genes ◽  
Virulence Gene ◽  
Human Consumption ◽  
Gene Profiles ◽  
Healthy Sheep ◽  
Uremic Syndrome ◽  
Australian Sheep ◽  
Cattle And Sheep

ABSTRACT Shiga toxin-producing Escherichia coli (STEC) strains possessing genes for enterohemolysin (ehxA) and/or intimin (eae), referred to here as complex STEC (cSTEC), are more commonly recovered from the feces of humans with hemolytic uremic syndrome and hemorrhagic colitis than STEC strains that do not possess these accessory virulence genes. Ruminants, particularly cattle and sheep, are recognized reservoirs of STEC populations that may contaminate foods destined for human consumption. We isolated cSTEC strains from the feces of longitudinally sampled pasture-fed sheep, lot-fed sheep maintained on diets comprising various combinations of silage and grain, and sheep simultaneously grazing pastures with cattle to explore the diversity of cSTEC serotypes capable of colonizing healthy sheep. A total of 67 cSTEC serotypes were isolated, of which 21 (31.3%), mainly isolated from lambs, have not been reported. Of the total isolations, 58 (86.6%) were different from cSTEC serotypes isolated from a recent study of longitudinally sampled healthy Australian cattle (M. Hornitzky, B. A. Vanselow, K. Walker, K. A. Bettelheim, B. Corney, P. Gill, G. Bailey, and S. P. Djordjevic, Appl. Environ. Microbiol. 68:6439-6445, 2002). Our data suggest that cSTEC serotypes O5:H−, O75:H8, O91:H−, O123:H−, and O128:H2 are well adapted to colonizing the ovine gastrointestinal tract, since they were the most prevalent serotypes isolated from both pasture-fed and lot-fed sheep. Collectively, our data show that Australian sheep are colonized by diverse cSTEC serotypes that are rarely isolated from healthy Australian cattle.

scholarly journals Shiga Toxin-Producing Escherichia coli (STEC) and STEC-Associated Virulence Genes in Raw Ground Pork in Canada

2021 ◽  
Author(s):  
Helen Zhang ◽  
Etsuko Yamamoto ◽  
Johanna Murphy ◽  
Catherine Carrillo ◽  
Annie Locas
Keyword(s):  
Escherichia Coli ◽  
Foodborne Pathogens ◽  
Shiga Toxin ◽  
Virulence Genes ◽  
Virulence Gene ◽  
Toxin Gene ◽  
Gene Profiles ◽  
Ground Pork ◽  
Genes Encoding ◽  
Human Illness

Shiga toxin-producing Escherichia coli (STEC) O157:H7/NM and some non-O157 STEC are foodborne pathogens. In response to pork-associated O157 STEC outbreaks in Canada, we investigated the occurrence of STEC in Canadian retail raw ground pork during the period of November 1, 2014 and March 31, 2016. Isolated STEC were characterized to determine the Shiga-toxin gene ( stx ) subtype and the presence of virulence genes encoding intimin ( eae ), and enterohemorrhagic E. coli hemolysin (hlyA) . O157 STEC and non-O157 STEC were isolated from 0.11% (1/879) and 2.24% (13/580) of the pork samples. STEC virulence gene profiles containing both eae and hlyA were found only in the O157 STEC ( stx 2a , eae , hlyA ) isolate. The eae gene was absent from all non-O157 STEC isolates. Of the 13 non-O157 STEC isolates, two virulence genes of stx 1a and hlyA were found in four (30.8%) O91:H14 STEC isolates, while one virulence gene of stx 2e, stx 1a , and stx 2a was identified in five (38.5%), two (15.4%) and one (7.7%) STEC isolates respectively of various serotypes. The remaining non-O157 STEC isolate carried stx 2 , but the subtype is unknown as this isolate could not be recovered for sequencing. O91:H14 STEC ( stx 1a, hlyA ) was previously reported in association with diarrhea illnesses, while the other non-O157 STEC isolates identified in this study are not known to be associated with severe human illnesses. Virulence gene profiles identified in this study indicate that the occurrence of non-O157 STEC capable of causing severe human illness is rare in Canadian retail pork. However, O157 STEC in ground pork can occasionally occur, therefore education regarding the potential risks associated with STEC contamination of pork would be beneficial for the public and those in the food industry in order to help reduce foodborne illnesses.

scholarly journals Relationship between Virulence Gene Profiles of Atypical Enteropathogenic Escherichia coli and Shiga Toxin- Producing E. coli Isolates from Cattle and Sheep in New Zealand

2010 ◽  
Vol 76 (11) ◽  
pp. 3744-3747 ◽  
Author(s):  
Adrian L. Cookson ◽  
Mingshu Cao ◽  
Jenny Bennett ◽  
Carolyn Nicol ◽  
Fiona Thomson-Carter ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Shiga Toxin ◽  
Evolutionary Relationship ◽  
Virulence Gene ◽  
Type Ii Secretion ◽  
E Coli ◽  
Type Ii Secretion System ◽  
Gene Profiles ◽  
The Relationship ◽  
Cattle And Sheep

ABSTRACT Virulence gene profiles of atypical enteropathogenic Escherichia coli (aEPEC) and Shiga toxin-producing E. coli (STEC) from cattle, sheep, and humans were examined to determine the relationship between pathotypes. Shared virulence factors (intimin, EHEC hemolysin, serine protease, and a type II secretion system) were identified, suggesting a dynamic evolutionary relationship between aEPEC and STEC.

Detection of virulence genes of APEC (avian pathogenic Escherichia coli) isolated from poultry in Noakhali, Bangladesh

2021 ◽  
Vol 7 (1) ◽  
pp. 967-972
Author(s):  
Farzana Ehetasum Hossain ◽  
Saiful Islam ◽  
Md Aminul Islam ◽  
Shariful Islam ◽  
Firoz Ahmed
Keyword(s):  
Escherichia Coli ◽  
Virulence Genes ◽  
Virulence Gene ◽  
Economic Loss ◽  
Point Of View ◽  
Pcr Analysis ◽  
Avian Pathogenic Escherichia Coli ◽  
Gene Profiles ◽  
Pathogenic Escherichia Coli ◽  
Wide Range

Avian colibacillosis, caused by avian pathogenic Escherichia coli (APEC), is one of the major infectious diseases of poultry that bring about great economic loss for the Bangladesh poultry industry. The present study aimed to determine the virulence genes of avian pathogenic Escherichia coli (APEC) from cases of colibacillosis in poultry at the Noakhali district of Bangladesh. Currently, virulence-associated gene profiles of APEC isolates were investigated by polymerase chain reaction (PCR). A total of 24 (twenty-four) Escherichia coli isolates were collected and presumptively identified from 8 (eight) colibacillosis cases from 4 commercial broiler poultry farms (2 broilers per farm) in Noakhali, Bangladesh. The pathogenesis of Escherichia coli involves a wide range of different virulence genes. At this point, four virulence genes, iutA, hlyF, iroN, and iss were detected by PCR analysis. It has been observed that iutA, iss, hlyF, and iroN genes were found in 7(29.16%), 20(83.33%), 22(91.66%), and 24(100%) APEC isolates respectively. Furthermore, out of the twenty-four APEC isolates, six (25%) isolates had four virulence genes, fourteen (58.33%) isolates carried at least three virulence genes, three (12.5%) isolates carried two genes and one (4.16%) isolates had one virulence gene. Most importantly. six types of virulence gene profiles existed within the APEC isolates from which profile number 3 (hlyF, iroN, iss) having 13 (54.16%) isolates were predominant. The occurrence of APEC isolates of this region which is responsible for avian colibacillosis cases can be a matter of concern from the public health point of view. Future investigations will be able to utilize these virulence genes to identify APEC in Bangladesh helping in the diagnosis and prevention of colibacillosis in poultry. Bioresearch Commu. 7(1): 967-972, 2021 (January)

scholarly journals Virulence gene profiles of avian pathogenic Escherichia coli isolated from chickens with colibacillosis in Bulawayo, Zimbabwe

2015 ◽  
Vol 82 (1) ◽  
Author(s):  
Joshua Mbanga ◽  
Yvonne O. Nyararai
Keyword(s):  
Escherichia Coli ◽  
Virulence Genes ◽  
Virulence Gene ◽  
Economic Losses ◽  
Avian Pathogenic Escherichia Coli ◽  
Pcr Assay ◽  
E Coli ◽  
Gene Profiles ◽  
Pathogenic Escherichia Coli ◽  
Polymerase Chain

Colibacillosis, a disease caused by avian pathogenic Escherichia coli (APEC), is one of the main causes of economic losses in the poultry industry worldwide. This study was carried out in order to determine the APEC-associated virulence genes contained by E. coli isolates causing colibacillosis in chickens. A total of 45 E. coli isolates were obtained from the diagnostics and research branch of the Central Veterinary Laboratories, Bulawayo, Zimbabwe. These isolates were obtained from chickens with confirmed cases of colibacillosis after postmortem examination. The presence of the iutA, hlyF, ompT, frz, sitD, fimH, kpsM, sitA, sopB, uvrY, pstB and vat genes were investigated by multiplex polymerase chain reaction (PCR) assay. Of the 45 isolates, 93% were positive for the presence of at least one virulence gene. The three most prevalent virulence genes were iutA (80%), fimH (33.3%) and hlyF (24.4%). The kpsM, pstB and ompT genes had the lowest prevalence, having been detected in only 2.2% of the isolates. All 12 virulence genes studied were detected in the 45 APEC isolates. Virulence gene profiles were constructed for each APEC isolate from the multiplex data. The APEC isolates were profiled as 62.2% fitting profile A, 31.1% profile B and 6.7% profile C. None of the isolates had more than seven virulence genes. Virulence profiles of Zimbabwean APEC isolates are different from those previously reported. Zimbabwean APEC isolates appear to be less pathogenic and may rely on environmental factors and stress in hosts to establish infection.

scholarly journals Molecular Characterization of Shiga Toxin-Producing Escherichia coli Strains Isolated in Poland

2016 ◽  
Vol 65 (3) ◽  
pp. 261-269 ◽  
Author(s):  
Aleksandra Januszkiewicz ◽  
Waldemar Rastawicki
Keyword(s):  
Escherichia Coli ◽  
Virulence Factors ◽  
Shiga Toxin ◽  
Virulence Gene ◽  
Virulence Determinants ◽  
E Coli ◽  
Heat Stable ◽  
Food Borne ◽  
Wide Range ◽  
Uremic Syndrome

Shiga toxin-producing Escherichia coli (STEC) strains also called verotoxin-producing E. coli (VTEC) represent one of the most important groups of food-borne pathogens that can cause several human diseases such as hemorrhagic colitis (HC) and hemolytic – uremic syndrome (HUS) worldwide. The ability of STEC strains to cause disease is associated with the presence of wide range of identified and putative virulence factors including those encoding Shiga toxin. In this study, we examined the distribution of various virulence determinants among STEC strains isolated in Poland from different sources. A total of 71 Shiga toxin-producing E. coli strains isolated from human, cattle and food over the years 1996 – 2010 were characterized by microarray and PCR detection of virulence genes. As stx1a subtype was present in all of the tested Shiga toxin 1 producing E. coli strains, a greater diversity of subtypes was found in the gene stx2, which occurred in five subtypes: stx2a, stx2b, stx2c, stx2d, stx2g. Among STEC O157 strains we observed conserved core set of 14 virulence factors, stable in bacteria genome at long intervals of time. There was one cattle STEC isolate which possessed verotoxin gene as well as sta1 gene encoded heat-stable enterotoxin STIa characteristic for enterotoxigenic E. coli. To the best of our knowledge, this is the first comprehensive analysis of virulence gene profiles identified in STEC strains isolated from human, cattle and food in Poland. The results obtained using microarrays technology confirmed high effectiveness of this method in determining STEC virulotypes which provides data suitable for molecular risk assessment of the potential virulence of this bacteria.

scholarly journals Genes de virulencia en Aeromonas spp. (Aeromonadales: Aeromonadaceae) aisladas de Oreochromis spp. (Perciformes: Cichlidae) para consumo humano en México

2018 ◽  
Vol 66 (4) ◽  
Author(s):  
JESSICA LIZBETH Ortega Balleza ◽  
Alejandro Sánchez-Varela ◽  
Isabel C. Rodríguez-Luna ◽  
Xianwu Guo
Keyword(s):  
Escherichia Coli ◽  
Virulence Genes ◽  
Geographical Area ◽  
Virulence Gene ◽  
Gastrointestinal Diseases ◽  
Human Consumption ◽  
Emerging Pathogens ◽  
Pathogenic Potential ◽  
Aeromonas Caviae ◽  
And Control

The genus Aeromonas are widely distributed in aquatic ecosystems are Gram-negative rods, oxidase-positive, and glucose-fermenting, considered emerging pathogens in humans. Aeromonas belongs to the fish microbiota, these microorganisms have a diversity of virulence factors responsible for a variety of infections in humans mainly gastrointestinal diseases. The presence of Aeromonas in products intended for consumption with high commercial demand such as tilapia generates sanitary concern due to the pathogenic potential of this bacteria. In this context, identification of virulence genes in strains of Aeromonas isolated in Oreochromis spp. intended for human consumption in Reynosa, Tamaulipas, Mexico is important due to the lack of molecular studies in this geographical area. In the present study the pathogenic potential of 15 strains of Aeromonas (A. veronii, A. hydrophila and A. schubertii) from Oreochromis spp. for human consumption were analyzed. Through PCR six virulence genes were analyzed (alt, ast, aerA, hlyA, gcat and stx1) and the strains used as control were: Aeromonas hydrophila subsp. hydrophila ATCC 7966, Aeromonas caviae 429865 INP, Escherichia coli O157: H7 and Escherichia coli K12. El 100 % (n = 15) of the strains harbored at least one virulence gene, aerA gene was detected in 86.66% of the analyzed strains, while ast and stx1 genes were not identified. Moreover, Aeromonas strains had associated genes in the same strain: aerA / gcat, alt / aerA, alt / aerA / gcat / hlyA and alt / aerA / gcat, of which aerA / gcat were observed mostly in A. veronii, while A. hydrophila had the highest associations. These findings indicate that the strains of Aeromonas isolated in Oreochromis spp. have the potential to cause human diseases, and therefore, this species used as food, could be a vehicle for infections caused by Aeromonas. It also allows to provide information on this emerging microorganism to effectively treat and control any epidemiological event caused by Aeromonas spp. in the future.

scholarly journals Virulence Factor Gene Profiles of Escherichia coli Isolates from Clinically Healthy Pigs

2006 ◽  
Vol 72 (10) ◽  
pp. 6680-6686 ◽  
Author(s):  
Peter Schierack ◽  
Hartmut Steinrück ◽  
Sylvia Kleta ◽  
Wilfried Vahjen
Keyword(s):  
Escherichia Coli ◽  
Virulence Factor ◽  
Virulence Genes ◽  
Clinical Signs ◽  
Virulence Gene ◽  
Bacterial Populations ◽  
Factor Gene ◽  
E Coli ◽  
Gene Profiles ◽  
Virulence Factor Gene

ABSTRACT Nonpathogenic, intestinal Escherichia coli (commensal E. coli) supports the physiological intestinal balance of the host, whereas pathogenic E. coli with typical virulence factor gene profiles can cause severe outbreaks of diarrhea. In many reports, E. coli isolates from diarrheic animals were classified as putative pathogens. Here we describe a broad variety of virulence gene-positive E. coli isolates from swine with no clinical signs of intestinal disease. The isolation of E. coli from 34 pigs from the same population and the testing of 331 isolates for genes encoding heat-stable enterotoxins I and II, heat-labile enterotoxin I, Shiga toxin 2e, and F4, F5, F6, F18, and F41 fimbriae revealed that 68.6% of the isolates were positive for at least one virulence gene, with a total of 24 different virulence factor gene profiles, implying high rates of horizontal gene transfer in this E. coli population. Additionally, we traced the occurrence of hemolytic E. coli over a period of 1 year in this same pig population. Hemolytic isolates were differentiated into seven clones; only three were found to harbor virulence genes. Hemolytic E. coli isolates without virulence genes or with only the fedA gene were found to be nontypeable by slide agglutination tests with OK antisera intended for screening live cultures against common pathogenic E. coli serogroups. The results appear to indicate that virulence gene-carrying E. coli strains are a normal part of intestinal bacterial populations and that high numbers of E. coli cells harboring virulence genes and/or with hemolytic activity do not necessarily correlate with disease.

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