scholarly journals Indirect Transmission of Escherichia coli O157:H7 Occurs Readily among Swine but Not among Sheep

2008 ◽  
Vol 74 (8) ◽  
pp. 2488-2491 ◽  
Author(s):  
Nancy A. Cornick ◽  
Hung VuKhac

ABSTRACT Transmission of Escherichia coli O157:H7 among reservoir animals is generally thought to occur either by direct contact between a naïve animal and an infected animal or by consumption of food or water containing the organism. Although ruminants are considered the major reservoir, there are two reports of human infections caused by E. coli O157:H7 linked to the consumption of pork products or to the contamination of fresh produce by swine manure. The objective of this study was to determine whether E. coli O157:H7 could be transmitted to naïve animals, both sheep and swine, that did not have any direct contact with an infected donor animal. We recovered E. coli O157:H7 from 10/10 pigs with nose-to-nose contact with the infected donor or animals adjacent to the donor and from 5/6 naïve pigs that were penned in the same room as the donor pig but 10 to 20 ft away. In contrast, when the experiment was repeated with sheep, E. coli O157:H7 was recovered from 4/6 animals that had nose-to-nose contact with the infected donor or adjacent animals and from 0/6 naïve animals penned 10 to 20 ft away from the donor. These results suggest that E. coli O157:H7 is readily transmitted among swine and that transmission can occur by the creation of contaminated aerosols.

1999 ◽  
Vol 65 (7) ◽  
pp. 3233-3235 ◽  
Author(s):  
Carolyn J. Hovde ◽  
Paula R. Austin ◽  
Karen A. Cloud ◽  
Christopher J. Williams ◽  
Carl W. Hunt

ABSTRACT The duration of shedding of Escherichia coli O157 isolates by hay-fed and grain-fed steers experimentally inoculated withE. coli O157:H7 was compared, as well as the acid resistance of the bacteria. The hay-fed animals shed E. coli O157 longer than the grain-fed animals, and irrespective of diet, these bacteria were equally acid resistant. Feeding cattle hay may increase human infections with E. coli O157:H7.


2018 ◽  
Vol 7 (18) ◽  
Author(s):  
Serajus Salaheen ◽  
Seon Woo Kim ◽  
Jeffrey S. Karns ◽  
Bradd J. Haley ◽  
Jo Ann S. Van Kessel

Cattle are primary reservoirs of Escherichia coli O157:H7, a causative agent of severe human infections. To facilitate analyses of the communities in which this pathogen is found, we sequenced the fecal metagenomes of 10 dairy cows shedding E. coli O157:H7 and added them to the public domain.


2001 ◽  
Vol 127 (3) ◽  
pp. 555-560 ◽  
Author(s):  
T. E. BESSER ◽  
B. L. RICHARDS ◽  
D. H. RICE ◽  
D. D. HANCOCK

Cattle are considered to be a reservoir host of Escherichia coli O157[ratio ]H7 and contaminated foods of bovine origin are important vehicles of human infection. In this study, the susceptibility of calves to experimental E. coli O157[ratio ]H7 infection following low oral exposures was determined. Two of 17 calves exposed to very low (<300 c.f.u.) doses, and 3 of 4 calves exposed to low (<10000 c.f.u.) doses, subsequently excreted the challenge strains in their faeces. All calves (n = 12) sharing isolation rooms with calves that excreted the challenge strain in their faeces similarly began faecal excretion of the same strains within 21 days or less. The identity between the challenge strains and the strains excreted in calf faeces was confirmed by restriction digestion electrophoretic patterns using pulsed field gel electrophoresis. Calves shed E. coli O157[ratio ]H7 in their faeces after very low dose exposures at concentrations ranging from <30 to >107 c.f.u./g, and for durations similar to the values previously reported for calves challenged by larger doses. The susceptibility of calves to infection following very low exposures or direct contact with infected calves has important implications for programmes for pre-harvest control of this agent.


2006 ◽  
Vol 135 (2) ◽  
pp. 311-314 ◽  
Author(s):  
G. CONEDERA ◽  
E. MATTIAZZI ◽  
F. RUSSO ◽  
E. CHIESA ◽  
I. SCORZATO ◽  
...  

A family outbreak of Escherichia coli O157 infection was microbiologically associated with consumption of dry-fermented salami made with pork meat only and produced in a local plant. E. coli O157 strains isolated from a wife and husband, both hospitalized with bloody diarrhoea, and from the salami carried vt1, vt2 and eae genes and shared the same PFGE pattern. The food vehicle implicated in this outbreak is unusual because of both the animal species from which it originates and the fermentation and drying steps of the manufacturing process. This could be the first report of an outbreak associated with a product containing pork meat only. Even though sources of contamination other than pork meat could not be excluded, pork products should not be neglected in E. coli O157 outbreak investigations.


2008 ◽  
Vol 57 (11) ◽  
pp. 1389-1393 ◽  
Author(s):  
Henrik Chart ◽  
Thomas Cheasty

From 1997 to 2007, the Laboratory of Enteric Pathogens (LEP), Health Protection Agency, UK, received sera from 2148 patients for testing for antibodies to the LPS of verocytotoxin-producing Escherichia coli (VTEC) O157. A total of 676 (31.5 %) sera had antibodies binding the LPS of E. coli O157 and the majority of patients were below the age of 10 years, a trend observed for both males and females. Antibody-positive patients had haemolytic uraemic syndrome (HUS) in 79.3 % of cases and most of these presented with the atypical (D−) form of HUS. Nine patients were shown to have antibodies to the LPS of E. coli belonging to serogroups O26 (4), O103 (2), O111 (1) and O145 (2) and one patient had antibodies to the somatic antigens of both E. coli O26 and O103. The serodiagnosis of infections with E. coli O157 and other VTEC continues to be an important adjunct to bacteriology. Where clinicians suspect the involvement of a VTEC in disease, patients' sera should be submitted to the LEP for analysis without delay.


2005 ◽  
Vol 54 (5) ◽  
pp. 485-492 ◽  
Author(s):  
R M La Ragione ◽  
N MY Ahmed ◽  
A Best ◽  
D Clifford ◽  
U Weyer ◽  
...  

Enterohaemorrhagic Escherichia coli O157 : H7 infections of man have been associated with consumption of unpasteurized goat's milk and direct contact with kid goats on petting farms, yet little is known about colonization of goats with this organism. To assess the contribution of flagella and intimin of E. coli O157 : H7 in colonization of the goat, 8-week-old conventionally reared goats were inoculated orally in separate experiments with 1×1010 c.f.u. of a non-verotoxigenic strain of E. coli O157 : H7 (strain NCTC 12900 Nalr), an aflagellate derivative (DMB1) and an intimin-deficient derivative (DMB2). At 24 h after inoculation, the three E. coli O157 : H7 strains were shed at approximately 5×104 c.f.u. (g faeces)−1 from all animals. Significantly fewer intimin-deficient bacteria were shed only on days 2 (P = 0.003) and 4 (P = 0.014), whereas from day 7 to 29 there were no differences. Tissues from three animals inoculated with wild-type E. coli O157 : H7 strain NCTC 12900 Nalr were sampled at 24, 48 and 96 h after inoculation and the organism was cultured from the large intestine of all three animals and from the duodenum and ileum of the animal examined at 96 h. Tissues were examined histologically but attaching-effacing (AE) lesions were not observed at any intestinal site of the animals examined at 24 or 48 h. However, the animal examined at 96 h, which had uniquely shed approximately 1×107 E. coli O157 : H7 (g faeces)−1 for the preceding 3 days, showed a heavy, diffuse infection with cryptosporidia and abundant, multifocal AE lesions in the distal colon, rectum and at the recto-anal junction. These AE lesions were confirmed by immunohistochemistry to be associated with E. coli O157 : H7.


2004 ◽  
Vol 70 (9) ◽  
pp. 5331-5335 ◽  
Author(s):  
N. A. Cornick ◽  
A. F. Helgerson

ABSTRACT Escherichia coli O157:H7 is only occasionally isolated from healthy swine, but some experimentally infected animals will shed the organism in their feces for at least 2 months. Potential explanations for the paucity of naturally occurring infections in swine, as compared to cattle, include a lack of animal-to-animal transmission so that the organism cannot be maintained within a herd, a high infectious dose, or herd management practices that prevent the maintenance of the organism in the gastrointestinal tract. We hypothesized that donor pigs infected with E. coli O157:H7 would transmit the organism to naïve pigs. We also determined the infectious dose and whether housing pigs individually on grated floors would decrease the magnitude or duration of fecal shedding. Infected donor pigs shedding <104 CFU of E. coli O157:H7 per g transmitted the organism to 6 of 12 naïve pigs exposed to them. The infectious dose of E. coli O157:H7 for 3-month-old pigs was approximately 6 × 103 CFU. There was no difference in the magnitude and duration of fecal shedding by pigs housed individually on grates compared to those housed two per pen on cement floors. These results suggest that swine do not have an innate resistance to colonization by E. coli O157:H7 and that they could serve as a reservoir host under suitable conditions.


2013 ◽  
Vol 20 (4) ◽  
pp. 562-571 ◽  
Author(s):  
Kathryn G. Boland ◽  
Andrea N. Hayles ◽  
Claire B. Miller ◽  
Tovah Kerr ◽  
Wendy C. Brown ◽  
...  

ABSTRACTEscherichia coliO157:H7 is an enteric pathogen of animals and humans that can result in deadly sequelae. Cattle are asymptomatic carriers and shedders of the bacteria and serve as an important reservoir of human infection.E. coliO157:H7 colonizes the gastrointestinal tract, most frequently at the rectoanal junction mucosa in cattle. Vaccination is a potentially highly effective means of decreasing cattle colonization and shedding and thereby decreasing human infections. Currently available vaccines are administered subcutaneously or intramuscularly, and immune responses have been evaluated solely by systemic immunoglobulin responses. This study evaluated local and systemic lymphoproliferative responses in addition to immunoglobulin responses following subcutaneous or mucosal (rectal) immunization withE. coliO157:H7 outer membrane protein intimin over three trials. In all three trials, significant local and systemic lymphoproliferative responses (P< 0.05) occurred following immunization in the majority of animals, as well as significant immunoglobulin responses (P< 0.001) in all animals. Surprisingly, local responses in the mesorectal lymph nodes were very similar between the subcutaneous and mucosal immunization groups. Moreover, the responses in mesorectal lymph nodes appeared targeted rather than generalized, as minimal or no significant responses were observed in the associated prescapular lymph nodes of subcutaneously immunized animals. The results indicate that both subcutaneous and mucosal immunizations are effective methods of inducing immune responses againstE. coliO157:H7 in cattle.


2007 ◽  
Vol 76 (2) ◽  
pp. 845-856 ◽  
Author(s):  
Guanghui Wu ◽  
Ben Carter ◽  
Muriel Mafura ◽  
Ernesto Liebana ◽  
Martin J. Woodward ◽  
...  

ABSTRACT An Escherichia coli oligonucleotide microarray based on three sequenced genomes was validated for comparative genomic microarray hybridization and used to study the diversity of E. coli O157 isolates from human infections and food and animal sources. Among 26 test strains, 24 (including both Shiga toxin [Stx]-positive and -negative strains) were found to be related to the two sequenced E. coli O157:H7 strains, EDL933 and Sakai. However, these strains showed much greater genetic diversity than those reported previously, and most of them could not be categorized as either lineage I or II. Some genes were found more often in isolates from human than from nonhuman sources; e.g., ECs1202 and ECs2976, associated with stx2AB and stx1AB, were in all isolates from human sources but in only 40% of those from nonhuman sources. Some (but not all) lineage I-specific or -dominant genes were also more frequently associated with isolates from human. The results suggested that it might be more effective to concentrate our efforts on finding markers that are directly related to infection rather than those specific to certain lineages. In addition, two Stx-negative O157 cattle isolates (one confirmed to be H7) were significantly different from other Stx-positive and -negative E. coli O157:H7 strains and were more similar to MG1655 in their gene content. This work demonstrates that not all E. coli O157:H7 strains belong to the same clonal group, and those that were similar to E. coli K-12 might be less virulent.


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