Testing of Swine Feces Obtained through the National Animal Health Monitoring System's Swine 2000 Study for the Presence of Escherichia coli O157:H7†

2007 ◽  
Vol 70 (6) ◽  
pp. 1489-1492 ◽  
Author(s):  
INGRID FEDER ◽  
JEFFREY T. GRAY ◽  
RACHEL A. PEARCE ◽  
PINA M. FRATAMICO ◽  
ERIC BUSH ◽  
...  

Fecal samples collected from healthy pigs from 13 of the top 17 swine-producing states were tested for Escherichia coli O157:H7 as part of the National Animal Health Monitoring System Swine 2000 study. Serogroup O157 strains were isolated from 106 of 2,526 fecal samples. None of the isolates were positive by PCR for the fliC h7 (H7 flagellin) gene or for the hly933 (hemolysin) gene; however, one isolate was positive for the stx1 gene (Shiga toxin 1), an additional four isolates were positive for the stx2 gene (Shiga toxin 2), and three isolates possessed the eae gene (intimin).

2004 ◽  
Vol 70 (12) ◽  
pp. 7173-7178 ◽  
Author(s):  
Pina M. Fratamico ◽  
Lori K. Bagi ◽  
Eric J. Bush ◽  
Barbara T. Solow

ABSTRACT A study was conducted to determine the prevalence of Shiga toxin-producing Escherichia coli (STEC) in swine feces in the United States as part of the National Animal Health Monitoring System's Swine 2000 study. Fecal samples collected from swine operations from 13 of the top 17 swine-producing states were tested for the presence of STEC. After enrichment of swine fecal samples in tryptic soy broth, the samples were tested for the presence of stx 1 and stx 2 by use of the TaqMan E. coli STX1 and STX2 PCR assays. Enrichments of samples positive for stx 1 and/or stx 2 were plated, and colony hybridization was performed using digoxigenin-labeled probes complementary to the stx 1 and stx 2 genes. Positive colonies were picked and confirmed by PCR for the presence of the stx 1, stx 2, or stx 2e genes, and the isolates were serotyped. Out of 687 fecal samples tested using the TaqMan assays, 70% (484 of 687) were positive for Shiga toxin genes, and 54% (370 of 687), 64% (436 of 687), and 38% (261 of 687) were positive for stx 1, stx 2, and both toxin genes, respectively. Out of 219 isolates that were characterized, 29 (13%) produced stx 1, 14 (6%) produced stx 2, and 176 (80%) produced stx 2e. Twenty-three fecal samples contained at least two STEC strains that had different serotypes but that had the same toxin genes or included a strain that possessed stx 1 in addition to a strain that possessed stx 2 or stx 2e. The STEC isolates belonged to various serogroups, including O2, O5, O7, O8, O9, OX10, O11, O15, OX18, O20, O57, O65, O68, O69, O78, O91, O96, O100, O101, O120, O121, O152, O159, O160, O163, and O untypeable. It is noteworthy that no isolates of serogroup O157 were recovered. Results of this study indicate that swine in the United States harbor STEC that can potentially cause human illness.


2010 ◽  
Vol 73 (4) ◽  
pp. 649-656 ◽  
Author(s):  
M. O. MASANA ◽  
G. A. LEOTTA ◽  
L. L. DEL CASTILLO ◽  
B. A. D'ASTEK ◽  
P. M. PALLADINO ◽  
...  

In Argentina, Escherichia coli O157:H7/NM (STEC O157) is the prevalent serotype associated with hemolytic uremic syndrome (HUS), which is endemic in the country with more than 400 cases per year. In order to estimate the prevalence and characteristics of STEC O157 in beef cattle at slaughter, a survey of 1,622 fecal and carcass samples was conducted in nine beef exporting abattoirs from November 2006 to April 2008. A total of 54 samples were found positive for STEC O157, with an average prevalence of 4.1% in fecal content and 2.6% in carcasses. Calves and heifers presented higher percentages of prevalence in feces, 10.5 and 8.5%, respectively. All STEC O157 isolates harbored stx2 (Shiga toxin 2), eae (intimin), ehxA (enterohemolysin), and fliCH7 (H7 flagellin) genes, while stx1 (Shiga toxin 1) was present in 16.7% of the strains. The prevalent (56%) stx genotype identified was stx2 combined with variant stx2c (vh-a), the combination of which is also prevalent (>90%) in STEC O157 post–enteric HUS cases in Argentina. The clonal relatedness of STEC O157 strains was established by phage typing and pulsed-field gel electrophoresis (PFGE). The 54 STEC isolates were categorized into 12 different phage types and in 29 XbaI-PFGE patterns distributed in 27 different lots. STEC O157 strains isolated from 5 of 21 carcasses were identical by PFGE (100% similarity) to strains of the fecal content of the same or a contiguous bovine in the lot. Five phage type–PFGE–stx profiles of 10 strains isolated in this study matched with the profiles of the strains recovered from 18 of 122 HUS cases that occurred in the same period.


Gene ◽  
2003 ◽  
Vol 309 (1) ◽  
pp. 35-48 ◽  
Author(s):  
Toshio Sato ◽  
Takeshi Shimizu ◽  
Masahisa Watarai ◽  
Midori Kobayashi ◽  
Shigeyuki Kano ◽  
...  

2006 ◽  
Vol 69 (2) ◽  
pp. 260-266 ◽  
Author(s):  
M. KAUFMANN ◽  
C. ZWEIFEL ◽  
M. BLANCO ◽  
J. E. BLANCO ◽  
J. BLANCO ◽  
...  

Fecal samples from 630 slaughtered finisher pigs were examined by PCR to assess the shedding of Escherichia coli O157 (rfbE) and Shiga toxin–producing E. coli (STEC, stx). The proportion of positive samples was 7.5% for rfbE and 22% for stx. By colony hybridization, 31 E. coli O157 and 45 STEC strains were isolated, and these strains were further characterized by phenotypic and genotypic traits. Among E. coli O157 strains, 30 were sorbitol positive, 30 had an H type other than H7, and none harbored stx genes. Intimin (eae), enterohemolysin (ehxA), EAST1 (astA), and porcine A/E–associated protein (paa) were present in 10, 3, 26, and 6% of strains. Among them, one eae-γ1–positive O157:H7 strain testing positive for ehxA and astA and two eae-α1–positive O157:H45 strains were classified as enteropathogenic E. coli (EPEC). The O157:H45 EPEC harbored the EAF plasmid and the bfpA gene, factors characteristic for typical EPEC. The isolated STEC strains (43 sorbitol positive) belonged to 11 O:H serotypes, including three previously reported in human STEC causing hemolytic uremic syndrome (O9:H−, O26:H−, and O103:H2). All but one strain harbored stx2e. The eae and ehxA genes, which are strongly correlated with human disease, were present in only one O103:H2 strain positive for stx1 and paa, whereas the astA gene was found more frequently (14 strains). High prevalence of STEC was found among finisher pigs, but according to the virulence factors the majority of these strains seem to be of low virulence.


2015 ◽  
Vol 78 (10) ◽  
pp. 1812-1818 ◽  
Author(s):  
HUSSNI O. MOHAMMED ◽  
KORANA STIPETIC ◽  
AHMED SALEM ◽  
PATRICK McDONOUGH ◽  
YUNG FU CHANG ◽  
...  

Escherichia coli O157:H7, non-O157 E. coli, and Campylobacter spp. are among the top-ranked pathogens that threaten the safety of food supply systems around the world. The associated risks and predisposing factors were investigated in a dynamic animal population using a repeat-cross-sectional study design. Animal and environmental samples were collected from dairy and camel farms, chicken processing plants, and abattoirs and analyzed for the presence of these pathogens using a combination of bacterial enrichment and real-time PCR tests without culture confirmation. Data on putative risk factors were also collected and analyzed. E. coli O157:H7 was detected by PCR at higher levels in sheep and camel feces than in cattle feces (odds ratios [OR], 6.8 and 21.1, respectively). Although the genes indicating E. coli O157:H7 were detected at a relatively higher rate (4.3%) in fecal samples from dairy cattle, they were less common in milk and udder swabs from the same animals (1 and 2%, respectively). Among the food adulterants, E. coli O103 was more common in cattle fecal samples, whereas O26 was more common in sheep feces and O45 in camel feces compared with cattle (OR, 2.6 and 3.1, respectively). The occurrence of E. coli in the targeted populations differed by the type of sample and season of the year. Campylobacter jejuni and Campylobacter coli were more common in sheep and camel feces than in cattle feces. Most of the survey and surveillance of E. coli focused on serogroup O157 as a potential foodborne hazard; however, based on the PCR results, non-O157 Shiga toxin–producing E. coli serotypes appeared to be more common, and efforts should be made to include them in food safety programs.


2006 ◽  
Vol 69 (12) ◽  
pp. 3018-3020 ◽  
Author(s):  
M. J. ALAM ◽  
L. ZUREK

Cattle are an asymptomatic reservoir of Escherichia coli O157:H7, but the bacterial colonization and shedding patterns are poorly understood. The prevalence and shedding of this human pathogen have been reported to be seasonal with rates typically increasing during warm months. The objectives of this study were (i) to assess the prevalence of E. coli O157:H7 in feces of feedlot cattle in Kansas during summer, fall, and winter months, and (ii) to characterize E. coli O157:H7 by screening for virulence factors. Of 891 fecal samples collected, 82 (9.2%) were positive for E. coli O157:H7. No significant differences in prevalence were detected among summer, fall, and winter months. The highest monthly prevalence (18.1%) was detected in February. All tested isolates were positive for stx2 (Shiga toxin 2) and eaeA (intimin) genes; 14 isolates (12.8%) also carried stx1. Our results indicate the prevalence of E. coli O157:H7 in beef cattle feces is not necessarily season dependent.


2012 ◽  
Vol 159 (3) ◽  
pp. 186-192 ◽  
Author(s):  
Shaun M. Harris ◽  
Wan-Fu Yue ◽  
Sarena A. Olsen ◽  
Jia Hu ◽  
Warrie J. Means ◽  
...  

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