Dataset Information

Verotoxins in bovine and meat verotoxin-producing Escherichia coli isolates: type, number of variants, and relationship to cytotoxicity.

ABSTRACT: In this study, we determined vt subtypes and evaluated verotoxicity in basal as well as induced conditions of verotoxin-producing Escherichia coli (VTEC) strains isolated from cattle and meat products. Most (87%) of the 186 isolates carried a vt(2) gene. Moreover, the vt(2) subtype, which is associated with serious disease, was present in 42% of our VTEC collection. The other vt subtypes detected were vt(1), vt(1d), vt(2vha), vt(2vhb), vt(2O118), vt(2d) (mucus activatable), and vt(2g). A total of 41 (22%) of the isolates possessed more than one vt subtype in its genome, and among them the most frequent combination was vt(1)/vt(2), but we also observed multiple combinations among vt(2) subtypes. Differences in verotoxicity titers were found among a selection of 54 isolates. Among isolates with a single vt(2) variant, those carrying the vt(2) subtype had high titers under both uninduced and induced conditions. However, the highest increase in cytotoxicity under mitomycin C treatment was detected among the strains carrying vt(2vha) or vt(2hb) variants. Notably, the isolates carrying the vt(1) subtype showed a lesser increase than that of most of the vt(2)-positive VTEC strains. Furthermore, the presence of more than one vt gene variant in the same isolate was not reflected in higher titers, and generally the titers were lower than those for strains with only one gene variant. The main observation was that both basal and induced cytotoxic effects seemed to be associated with the type and number of vt variants more than with the serotype or origin of the isolate.

SUBMITTER: Kruger A

PROVIDER: S-EPMC3019693 | biostudies-literature | 2011 Jan

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Verotoxins in bovine and meat verotoxin-producing Escherichia coli isolates: type, number of variants, and relationship to cytotoxicity.

Krüger Alejandra A Lucchesi Paula M A PM Parma Alberto E AE

Applied and environmental microbiology 20101029 1

In this study, we determined vt subtypes and evaluated verotoxicity in basal as well as induced conditions of verotoxin-producing Escherichia coli (VTEC) strains isolated from cattle and meat products. Most (87%) of the 186 isolates carried a vt(2) gene. Moreover, the vt(2) subtype, which is associated with serious disease, was present in 42% of our VTEC collection. The other vt subtypes detected were vt(1), vt(1d), vt(2vha), vt(2vhb), vt(2O118), vt(2d) (mucus activatable), and vt(2g). A total o ...[more]

PMID: 21037301

Similar Datasets

Project description:The use of antibiotics in food animals is of public health concern, because resistant zoonotic pathogens can be transmitted to humans. Furthermore, global trade with food may rapidly spread multi-resistant pathogens between countries and even continents. The purpose of the study was to investigate whether imported chicken meat and meat from locally reared chicken are potential sources for human exposure to multi resistant Escherichia coli isolates. 188 samples from imported and locally produced chicken meat were sampled and analyzed. 153 bacteria isolates were successfully cultured and identified as E. coli using MALDI-ToF. Of these 109 isolates were from meat whereas the remaining 44 were isolated from the cloaca of locally reared live chickens. Antimicrobial susceptibility test was done on the identified E. coli isolates. Additionally, beta-lactamases production (ESBL and/or AmpC) were phenotypically confirmed on all isolates showing resistance to cefpodoxime. Beta-lactamase producing (BLP) E. coli meat isolates were further genotyped. Antimicrobial resistance to four antibiotic markers with highest resistance was detected more frequently in isolates from local chickens compared to imported chickens (tetracycline 88.9% vs. 57.5%, sulphonamide 75.0% vs. 46.6%, ampicillin 69.4% vs. 61.6% and trimethoprim 66.7% vs. 38.4%). Beta-lactamase production was found in 29 E. coli meat isolates, with 56.9% of them being multiple drug resistant (? 3). The predominant phylogroup identified was B1 followed by A and D, with similar distribution among the isolates from meat of locally reared chickens and imported chickens. Beta-lactamase producing genotype blaCTX-M-15 (50%; 10/20) was the most frequently drug resistant gene detected. More BLP E. coli isolates were found in imported chicken meat compared to locally reared chickens, demonstrating that these isolates may be spreading through food trade. In conclusion, both imported and locally produced chicken meats are potential sources for human exposure to BLP E. coli.

Project description:We have analyzed the prevalence of Shiga toxin-producing Escherichia coli (STEC) in stool specimens of patients with diarrhea or other gastrointestinal alterations from the Xeral-Calde Hospital of Lugo City (Spain). STEC strains were detected in 126 (2.5%) of 5,054 cases investigated, with a progressive increase in the incidence from 0% in 1992 to 4.4% in 1999. STEC O157:H7 was isolated in 24 cases (0.5%), whereas non-O157 STEC strains were isolated from 87 patients (1.7%). STEC strains were (after Salmonella and Campylobacter strains) the third most frequently recovered enteropathogenic bacteria. A total of 126 human STEC isolates were characterized in this study. PCR showed that 43 (34%) isolates carried stx(1) genes, 45 (36%) possessed stx(2) genes and 38 (30%) carried both stx(1) and stx(2). A total of 88 (70%) isolates carried an ehxA enterohemolysin gene, and 70 (56%) isolates possessed an eae intimin gene (27 isolates with type gamma1, 20 with type beta1, 8 with type zeta, 5 with type gamma2, and 3 with type epsilon). STEC isolates belonged to 41 O serogroups and 66 O:H serotypes, including 21 serotypes associated with hemolytic uremic syndrome and 30 new serotypes not previously reported among human STEC strains in other studies. Although the 126 STEC isolates belonged to 81 different seropathotypes (associations between serotypes and virulence genes), only four accounted for 31% of isolates. Seropathotype O157:H7 stx(1) stx(2) eae-gamma1 ehxA was the most common (13 isolates) followed by O157:H7 stx(2) eae-gamma1 ehxA (11 isolates), O26:H11 stx(1) eae-beta1 ehxA (11 isolates), and O111:H- stx(1) stx(2) eae-gamma2 ehxA (4 isolates). Our results suggest that STEC strains are a significant cause of human infections in Spain and confirm that in continental Europe, infections caused by STEC non-O157 strains are more common than those caused by O157:H7 isolates. The high prevalence of STEC strains (both O157:H7 and non-O157 strains) in human patients, and their association with serious complications, strongly supports the utilization of protocols for detection of all serotypes of STEC in Spanish clinical microbiology laboratories.

Project description:A total of 514 Shiga toxin-producing Escherichia coli (STEC) isolates from diarrheic and healthy cattle in Spain were characterized in this study. PCR showed that 101 (20%) isolates carried stx(1) genes, 278 (54%) possessed stx(2) genes, and 135 (26%) possessed both stx(1) and stx(2). Enterohemolysin (ehxA) and intimin (eae) virulence genes were detected in 326 (63%) and in 151 (29%) of the isolates, respectively. STEC isolates belonged to 66 O serogroups and 113 O:H serotypes (including 23 new serotypes). However, 67% were of one of these 15 serogroups (O2, O4, O8, O20, O22, O26, O77, O91, O105, O113, O116, O157, O171, O174, and OX177) and 52% of the isolates belonged to only 10 serotypes (O4:H4, O20:H19, O22:H8, O26:H11, O77:H41, O105:H18, O113:H21, O157:H7, O171:H2, and ONT:H19). Although the 514 STEC isolates belonged to 164 different seropathotypes (associations between serotypes and virulence genes), only 12 accounted for 43% of isolates. Seropathotype O157:H7 stx(2) eae-gamma1 ehxA (46 isolates) was the most common, followed by O157:H7 stx(1) stx(2) eae-gamma1 ehxA (34 isolates), O113:H21 stx(2) (25 isolates), O22:H8 stx(1) stx(2) ehxA (15 isolates), O26:H11 stx(1) eae-beta1 ehxA (14 isolates), and O77:H41 stx(2) ehxA (14 isolates). Forty-one (22 of serotype O26:H11) isolates had intimin beta1, 82 O157:H7 isolates possessed intimin gamma1, three O111:H- isolates had intimin type gamma2, one O49:H- strain showed intimin type delta, 13 (six of serotype O103:H2) isolates had intimin type epsilon and eight (four of serotype O156:H-) isolates had intimin zeta. We have identified a new variant of the eae intimin gene designated xi (xi) in two isolates of serotype O80:H-. The majority (85%) of bovine STEC isolates belonged to serotypes previously found for human STEC organisms and 54% to serotypes associated with STEC organisms isolated from patients with hemolytic uremic syndrome. Thus, this study confirms that cattle are a major reservoir of STEC strains pathogenic for humans.

Dataset Information

Verotoxins in bovine and meat verotoxin-producing Escherichia coli isolates: type, number of variants, and relationship to cytotoxicity.

Publications

Verotoxins in bovine and meat verotoxin-producing Escherichia coli isolates: type, number of variants, and relationship to cytotoxicity.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure