scholarly journals Assessment of Shiga Toxin-Producing Escherichia coli Isolates from Wildlife Meat as Potential Pathogens for Humans

2009 ◽  
Vol 75 (20) ◽  
pp. 6462-6470 ◽  
Author(s):  
Angelika Miko ◽  
Karin Pries ◽  
Sabine Haby ◽  
Katja Steege ◽  
Nadine Albrecht ◽  
...  

ABSTRACT A total of 140 Shiga toxin-producing Escherichia coli (STEC) strains from wildlife meat (deer, wild boar, and hare) isolated in Germany between 1998 and 2006 were characterized with respect to their serotypes and virulence markers associated with human pathogenicity. The strains grouped into 38 serotypes, but eight O groups (21, 146, 128, 113, 22, 88, 6, and 91) and four H types (21, 28, 2, and 8) accounted for 71.4% and 75.7% of all STEC strains from game, respectively. Eighteen of the serotypes, including enterohemorrhagic E. coli (EHEC) O26:[H11] and O103:H2, were previously found to be associated with human illness. Genes linked to high-level virulence for humans (stx 2, stx 2d, and eae) were present in 46 (32.8%) STEC strains from game. Fifty-four STEC isolates from game belonged to serotypes which are frequently found in human patients (O103:H2, O26:H11, O113:H21, O91:H21, O128:H2, O146:H21, and O146:H28). These 54 STEC isolates were compared with 101 STEC isolates belonging to the same serotypes isolated from farm animals, from their food products, and from human patients. Within a given serotype, most STEC strains were similar with respect to their stx genotypes and other virulence attributes, regardless of origin. The 155 STEC strains were analyzed for genetic similarity by XbaI pulsed-field gel electrophoresis. O103:H2, O26:H11, O113:H21, O128:H2, and O146:H28 STEC isolates from game were 85 to 100% similar to STEC isolates of the same strains from human patients. By multilocus sequence typing, game EHEC O103:H2 strains were attributed to a clonal lineage associated with hemorrhagic diseases in humans. The results from our study indicate that game animals represent a reservoir for and a potential source of human pathogenic STEC and EHEC strains.

2002 ◽  
Vol 128 (3) ◽  
pp. 357-362 ◽  
Author(s):  
N. FEGAN ◽  
P. DESMARCHELIER

There is very little human disease associated with enterohaemorrhagic Escherichia coli O157 in Australia even though these organisms are present in the animal population. A group of Australian isolates of E. coli O157:H7 and O157:H- from human and animal sources were tested for the presence of virulence markers and compared by XbaI DNA macrorestriction analysis using pulsed-field gel electrophoresis (PFGE). Each of 102 isolates tested contained the gene eae which encodes the E. coli attaching and effacing factor and all but one carried the enterohaemolysin gene, ehxA, found on the EHEC plasmid. The most common Shiga toxin gene carried was stx2c, either alone (16%) or in combination with stx1 (74%) or stx2 (3%). PFGE grouped the isolates based on H serotype and some clusters were source specific. Australian E. coli O157:H7 and H- isolates from human, animal and meat sources carry all the virulence markers associated with EHEC disease in humans therefore other factors must be responsible for the low rates of human infection in Australia.


2004 ◽  
Vol 70 (11) ◽  
pp. 6944-6947 ◽  
Author(s):  
Eva M�ller Nielsen ◽  
Marianne N. Skov ◽  
Jesper J. Madsen ◽  
Jens Lodal ◽  
J�rgen Br�chner Jespersen ◽  
...  

ABSTRACT Wild animals living close to cattle and pig farms (four each) were examined for verocytotoxin-producing Escherichia coli (VTEC; also known as Shiga toxin-producing E. coli). The prevalence of VTEC among the 260 samples from wild animals was generally low. However, VTEC isolates from a starling (Sturnus vulgaris) and a Norway rat (Rattus norvegicus) were identical to cattle isolates from the corresponding farms with respect to serotype, virulence profile, and pulsed-field gel electrophoresis type. This study shows that wild birds and rodents may become infected from farm animals or vice versa, suggesting a possible role in VTEC transmission.


2015 ◽  
Vol 53 (11) ◽  
pp. 3466-3473 ◽  
Author(s):  
M. Toro ◽  
L. V. Rump ◽  
G. Cao ◽  
J. Meng ◽  
E. W. Brown ◽  
...  

Although new serotypes of enterohemorrhagicEscherichia coli(EHEC) emerge constantly, the mechanisms by which these new pathogens arise and the reasons emerging serotypes tend to carry more virulence genes than otherE. coliare not understood. An insertion sequence (IS) excision enhancer (IEE) was discovered in EHEC O157:H7 that promoted the excision of IS3family members and generating various genomic deletions. One IS3family member, IS629, actively transposes and proliferates in EHEC O157:H7 and enterotoxigenicE. coli(ETEC) O139 and O149. The simultaneous presence of the IEE and IS629(and other IS3family members) may be part of a system promoting not only adaptation and genome diversification inE. coliO157:H7 but also contributing to the development of pathogenicity among predominant serotypes. Prevalence comparisons of these elements in 461 strains, representing 72 different serotypes and 5 preassigned seropathotypes (SPT) A to E, showed that the presence of these two elements simultaneously was serotype specific and associated with highly pathogenic serotypes (O157 and top non-O157 Shiga toxin-producing Escherichia coli [STEC]) implicated in outbreaks and sporadic cases of human illness (SPT A and B). Serotypes lacking one or both elements were less likely to have been isolated from clinical cases. Our comparisons of IEE sequences showed sequence variations that could be divided into at least three clusters. Interestingly, the IEE sequences from O157 and the top 10 non-O157 STEC serotypes fell into clusters I and II, while less commonly isolated serotypes O5 and O174 fell into cluster III. These results suggest that IS629and IEE elements may be acting synergistically to promote genome plasticity and genetic diversity among STEC strains, enhancing their abilities to adapt to hostile environments and rapidly take up virulence factors.


2021 ◽  
Author(s):  
Maja Velhner ◽  
Dalibor Todorović ◽  
Katarina Novović ◽  
Branko Jovčić ◽  
Gospava Lazić ◽  
...  

Abstract Although resistance to fluoroquinolones is common in E. coli isolates from farm and game animals in Serbia, currently no data are accessible on the occurrence of antibacterial resistances in E. coli isolates from gulls. Therefore, 45 cloacal swabs and 50 fecal samples from black-headed gulls were investigated for the presence of Escherichia coli isolates resistant to antibiotics. Multidrug resistance was detected in 22 E. coli isolates. High level resistance to fluoroquinolones was found in ten isolates with MIC values of ciprofloxacin ranging from 4 to 32 mg/L. Genotyping revealed single or double mutations in the quinolone resistance determining region (QRDR) of the gyrA or gyrA, parC and parE genes, respectively. Ten isolates showed resistance to extended-spectrum cephalosporin antibiotics. These ten isolates belonged to phylogenetic group B2 (five isolates), group D (four isolates) and group B1 (one isolate). An extended-spectrum β-lactamase resistance phenotype was detected in one isolate which carried the blaCTX-M-1 gene on a plasmid of the I2/FIB replicon type. Nine isolates carried blaCMY-2 genes, which were detected on conjugative plasmids in seven isolates. One transconjugant also carried hly, iroN, iss, ompT and cvaC virulence genes on the plasmid. Five different sequence types (ST38, ST2307, ST224, ST162 and ST34) were detected in E. coli isolates with ESBL or AmpC phenotype and genotype.


2017 ◽  
Vol 80 (12) ◽  
pp. 2078-2082 ◽  
Author(s):  
Catherine M. McAuley ◽  
Kate E. McMillan ◽  
Sean C. Moore ◽  
Narelle Fegan ◽  
Edward M. Fox

ABSTRACT Safe dairy food production starts at the farm level, with the presence of pathogens on farms potentially impacting the downstream food supply. Studies often commence with looking for pathogens in fecal material of farm animals, predominantly cows; however, pathogens may arise from other on-farm sources. In Australia, few studies have looked at the broader farm environment, particularly in relation to Escherichia coli and Salmonella. The present study characterized the genetic similarity of these pathogens from bovine, ovine, and caprine dairy farm environments and related this to the stx1, stx2, eae, or ehx virulence markers in E. coli and antibiotic resistance in Salmonella. E. coli isolates with indistinguishable genetic profiles and at least one of the virulence factors were found in multiple samples on the farms, although profiles were unique to each farm. E. coli O26 with stx1 from one bovine farm had a different fingerprint type than all of the other E. coli O26 isolates, which lacked the Shiga toxin genes. They were from a separate bovine farm and were themselves closely related. No antibiotic resistance was detected among Salmonella isolates to the 17 antibiotics tested. Three Salmonella serotypes were identified: Orion, Infantis, and Zanzibar. The published PCR serotyping method used misidentified Salmonella Zanzibar as Salmonella Javiana, which was revealed after conventional antisera-based serotyping; this illustrates the need for caution when using PCR techniques for Salmonella serotype identification. Of the three serotypes, Salmonella Orion was most prevalent and was potentially resident on the farm. This article describes the previously unreported genetic diversity of potentially pathogenic E. coli and Salmonella serotypes from the farm environments of three dairy animal species in Victoria, Australia.


2009 ◽  
Vol 76 (1) ◽  
pp. 203-211 ◽  
Author(s):  
Marie Bugarel ◽  
Lothar Beutin ◽  
Patrick Fach

ABSTRACT Rapid and specific detection of Shiga toxin-producing Escherichia coli (STEC) strains with a high level of virulence for humans has become a priority for public health authorities. This study reports on the development of a low-density macroarray for simultaneously testing the genes stx 1, stx 2, eae, and ehxA and six different nle genes issued from genomic islands OI-122 (ent, nleB, and nleE) and OI-71 (nleF, nleH1-2, and nleA). Various strains of E. coli isolated from the environment, food, animals, and healthy children have been compared with clinical isolates of various seropathotypes. The eae gene was detected in all enteropathogenic E. coli (EPEC) strains as well as in enterohemorrhagic E. coli (EHEC) strains, except in EHEC O91:H21 and EHEC O113:H21. The gene ehxA was more prevalent in EHEC (90%) than in STEC (42.66%) strains, in which it was unequally distributed. The nle genes were detected only in some EPEC and EHEC strains but with various distributions, showing that nle genes are strain and/or serotype specific, probably reflecting adaptation of the strains to different hosts or environmental niches. One characteristic nle gene distribution in EHEC O157:[H7], O111:[H8], O26:[H11], O103:H25, O118:[H16], O121:[H19], O5:H−, O55:H7, O123:H11, O172:H25, and O165:H25 was ent/espL2, nleB, nleE, nleF, nleH1-2, nleA. (Brackets indicate genotyping of the flic or rfb genes.) A second nle pattern (ent/espL2, nleB, nleE, nleH1-2) was characteristic of EHEC O103:H2, O145:[H28], O45:H2, and O15:H2. The presence of eae, ent/espL2, nleB, nleE, and nleH1-2 genes is a clear signature of STEC strains with high virulence for humans.


2000 ◽  
Vol 63 (11) ◽  
pp. 1583-1586 ◽  
Author(s):  
R. DOUGLAS SCHURMAN ◽  
HARRY HARIHARAN ◽  
SUSAN B HEANEY ◽  
KRIS RAHN

Fecal swabs obtained from a random sample of 1,000 beef slaughter steers and heifers from 123 Prince Edward Island (P.E.I.) farms were examined for the presence of Shiga toxin-producing Escherichia coli (STEC) using a Vero cell assay (VCA). Multiple isolates from each positive sample were tested similarly. VCA-positive isolates were confirmed as E. coli biochemically, tested for drug resistance, serotyped, and tested by polymerase chain reaction (PCR). Animals were classified as positive when an isolate was positive on VCA and the presence of the gene responsible for toxin production was confirmed by PCR. The prevalence of STEC in beef slaughter steers and heifers on P.E.I. was 4% (40 of 1,000). The total number of isolates was 43, and these comprised 26 serotypes, including 13 isolates belonging to 6 serotypes known to be associated with human illness. The most frequently isolated STEC serotype was E. coli O157 (5 isolates out of 43). Of the five E. coli O157 isolates, four were E. coli O157:H7, a serious human pathogen. The majority of STEC isolates, including all O157:H7, isolates, were susceptible to 16 commonly used antimicrobial drugs. According to PCR, 65% of the STEC isolates had the gene for Stx1. Four of these isolates, including two O157: H7, had genes for Shiga toxin (Stx)1 and Stx2.


2016 ◽  
Vol 54 (4) ◽  
pp. 1074-1081 ◽  
Author(s):  
Masahiro Kusumoto ◽  
Yuna Hikoda ◽  
Yuki Fujii ◽  
Misato Murata ◽  
Hirotsugu Miyoshi ◽  
...  

EnterotoxigenicEscherichia coli(ETEC) and Shiga toxin-producingE. coli(STEC) are important causes of diarrhea and edema disease in swine. The majority of swine-pathogenicE. colistrains belong to a limited range of O serogroups, including O8, O138, O139, O141, O147, O149, and O157, which are the most frequently reported strains worldwide. However, the circumstances of ETEC and STEC infections in Japan remain unknown; there have been few reports on the prevalence or characterization of swine-pathogenicE. coli. In the present study, we determined the O serogroups of 967E. coliisolates collected between 1991 and 2014 from diseased swine in Japan, and we found that O139, O149, O116, and OSB9 (O serogroup ofShigella boydiitype 9) were the predominant serogroups. We further analyzed these four O serogroups using pulsed-field gel electrophoresis (PFGE), multilocus sequence typing, and virulence factor profiling. Most of the O139 and O149 strains formed serogroup-specific PFGE clusters (clusters I and II, respectively), whereas the O116 and OSB9 strains were grouped together in the same cluster (cluster III). All of the cluster III strains belonged to a single sequence type (ST88) and carried genes encoding both enterotoxin and Shiga toxin. This PFGE cluster III/ST88 lineage exhibited a high level of multidrug resistance (to a median of 10 antimicrobials). Notably, these bacteria were resistant to fluoroquinolones. Thus, this lineage should be considered a significant risk to animal production due to the toxigenicity and antimicrobial resistance of these bacteria.


2005 ◽  
Vol 71 (1) ◽  
pp. 93-97 ◽  
Author(s):  
J. Christopher Low ◽  
Iain J. McKendrick ◽  
Caroline McKechnie ◽  
David Fenlon ◽  
Stuart W. Naylor ◽  
...  

ABSTRACT Escherichia coli O157:H7 is an important cause of diarrhea, hemorrhagic colitis, and potentially fatal human illness. Cattle are considered a primary reservoir of infection, and recent experimental evidence has indicated that the terminal rectum is the principal site of bacterial carriage. To test this finding in naturally colonized animals, intact rectum samples from 267 cattle in 24 separate lots were obtained immediately after slaughter, and fecal material and mucosal surfaces were cultured for E. coli O157 by direct and enrichment methods. Two locations, 1 and 15 cm proximal to the recto-anal junction, were tested. In total, 35 animals were positive for E. coli O157 at at least one of the sites and 232 animals were negative as determined by all tests. The frequency of isolation and the numbers of E. coli O157 cells were higher at the site closer to the recto-anal junction, confirming our previous experimental findings. We defined low- and high-level carriers as animals with E. coli O157 levels of <1 � 103 CFU g−1 or <1 � 103 CFU ml−1 and animals with E. coli O157 levels of ≥1 � 103 CFU g−1 or ≥1 � 103 CFU ml−1 in feces or tissues, respectively. High-level carriage was detected in 3.7% of the animals (95% confidence interval, 1.8 to 6.8%), and carriage on the mucosal surface of the terminal rectum was associated with high-level fecal excretion. In summary, our results support previous work demonstrating that the mucosal epithelium in the bovine terminal rectum is an important site for E. coli O157 carriage in cattle. The data also support the hypothesis that high-level fecal shedding (≥1 � 103 CFU g of feces−1) of enterohemorrhagic E. coli O157 results from colonization of this site.


2015 ◽  
Vol 82 (4) ◽  
pp. 1090-1101 ◽  
Author(s):  
Michelle Qiu Carter ◽  
Beatriz Quinones ◽  
Xiaohua He ◽  
Wayne Zhong ◽  
Jacqueline W. Louie ◽  
...  

ABSTRACTShiga toxin-producingEscherichia coli(STEC) serotype O145 is one of the major non-O157 serotypes associated with severe human disease. Here we examined the genetic diversity, population structure, virulence potential, and antimicrobial resistance profiles of environmental O145 strains recovered from a major produce production region in California. Multilocus sequence typing analyses revealed that sequence type 78 (ST-78), a common ST in clinical strains, was the predominant genotype among the environmental strains. Similarly, all California environmental strains belonged to H28, a common H serotype in clinical strains. Although most environmental strains carried an intactfliCgene, only one strain retained swimming motility. Diversestxsubtypes were identified, includingstx1a,stx2a,stx2c, andstx2e. Although no correlation was detected between thestxgenotype and Stx1 production, high Stx2 production was detected mainly in strains carryingstx2aonly and was correlated positively with the cytotoxicity of Shiga toxin. All environmental strains were capable of producing enterohemolysin, whereas only 10 strains were positive for anaerobic hemolytic activity. Multidrug resistance appeared to be common, as nearly half of the tested O145 strains displayed resistance to at least two different classes of antibiotics. The core virulence determinants of enterohemorrhagicE. coliwere conserved in the environmental STEC O145 strains; however, there was large variation in the expression of virulence traits among the strains that were highly related genotypically, implying a trend of clonal divergence. Several cattle isolates exhibited key virulence traits comparable to those of the STEC O145 outbreak strains, emphasizing the emergence of hypervirulent strains in agricultural environments.


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