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Auvray F, Bièche-Terrier C, Um MM, Dupouy V, Nzuzi N, David L, Allais L, Drouet M, Oswald E, Bibbal D, Brugère H. Prevalence and characterization of the seven major serotypes of Shiga toxin-producing Escherichia coli (STEC) in veal calves slaughtered in France. Vet Microbiol 2023; 282:109754. [PMID: 37116423 DOI: 10.1016/j.vetmic.2023.109754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2022] [Revised: 04/17/2023] [Accepted: 04/22/2023] [Indexed: 04/30/2023]
Abstract
Shiga toxin (Stx)-producing Escherichia coli (STEC) belonging to the "top 7″ serotypes (i.e. O157:H7, O26:H11, O45:H2, O103:H2, O111:H8, O121:H19 and O145:H28) are considered as the main pathogenic enterohemorrhagic E. coli (EHEC). As ruminants, including calves, are a reservoir of pathogenic STEC, we investigated the prevalence, major virulence genes and genetic relatedness of top7 STEC in veal calves slaughtered in France, through the analysis of 500 fecal samples collected over one year. Thirty top7 STEC isolates were recovered from 28 calves. The two serotypes O103:H2 and O26:H11 accounted for 73% of STEC strains, followed by O145:H28 and O157:H7. STEC super-shedding levels were identified for two calves carrying STEC O103:H2 and O157:H7, respectively. Thirty-nine atypical enteropathogenic E. coli (aEPEC) were also recovered from calves. Overall, a prevalence of 5.6% top7 STEC-positive calves was found, thus higher than that previously determined for the French slaughtered adult cattle (1.8%), confirming the impact of animals age on STEC carriage. Most top7 STEC strains carried the stx1a subtype suggesting a low pathogenicity for humans. Seasonal variation in STEC carriage was also observed, with two peaks of higher prevalence during spring and fall. Genetic similarity of top7 STEC isolates was found for calves originating from the same fattening facilities, reflecting STEC circulation between animals kept in groups. This study indicates that veal calves grown for meat production are at higher risk of shedding top7 STEC compared to adult cattle. They thus represent ideal targets for the implementation of farm interventions aimed at reducing STEC burden in cattle and the food chain.
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Affiliation(s)
- Frédéric Auvray
- IRSD, Université de Toulouse, INSERM, INRAE, ENVT, UPS, Toulouse, France.
| | | | - Maryse Michèle Um
- IRSD, Université de Toulouse, INSERM, INRAE, ENVT, UPS, Toulouse, France
| | | | - Nathalie Nzuzi
- IRSD, Université de Toulouse, INSERM, INRAE, ENVT, UPS, Toulouse, France
| | - Laure David
- IRSD, Université de Toulouse, INSERM, INRAE, ENVT, UPS, Toulouse, France
| | - Laurent Allais
- Institut de l'Elevage, Laboratoire Analyse et Technologie des Produits, Villers Bocage, France
| | - Marie Drouet
- Institut de l'Elevage, Service Qualité des Viandes, Villers Bocage, France
| | - Eric Oswald
- IRSD, Université de Toulouse, INSERM, INRAE, ENVT, UPS, Toulouse, France; CHU de Toulouse, Hôpital Purpan, Toulouse, France
| | - Delphine Bibbal
- IRSD, Université de Toulouse, INSERM, INRAE, ENVT, UPS, Toulouse, France; InTheRes, Université de Toulouse, INRAE, ENVT, Toulouse, France
| | - Hubert Brugère
- IRSD, Université de Toulouse, INSERM, INRAE, ENVT, UPS, Toulouse, France
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Ray R, Singh P. Prevalence and Implications of Shiga Toxin-Producing E. coli in Farm and Wild Ruminants. Pathogens 2022; 11:1332. [PMID: 36422584 PMCID: PMC9694250 DOI: 10.3390/pathogens11111332] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2022] [Revised: 11/04/2022] [Accepted: 11/08/2022] [Indexed: 08/27/2023] Open
Abstract
Shiga-toxin-producing Escherichia coli (STEC) is a food-borne pathogen that causes human gastrointestinal infections across the globe, leading to kidney failure or even death in severe cases. E. coli are commensal members of humans and animals' (cattle, bison, and pigs) guts, however, may acquire Shiga-toxin-encoded phages. This acquisition or colonization by STEC may lead to dysbiosis in the intestinal microbial community of the host. Wildlife and livestock animals can be asymptomatically colonized by STEC, leading to pathogen shedding and transmission. Furthermore, there has been a steady uptick in new STEC variants representing various serotypes. These, along with hybrids of other pathogenic E. coli (UPEC and ExPEC), are of serious concern, especially when they possess enhanced antimicrobial resistance, biofilm formation, etc. Recent studies have reported these in the livestock and food industry with minimal focus on wildlife. Disturbed natural habitats and changing climates are increasingly creating wildlife reservoirs of these pathogens, leading to a rise in zoonotic infections. Therefore, this review comprehensively surveyed studies on STEC prevalence in livestock and wildlife hosts. We further present important microbial and environmental factors contributing to STEC spread as well as infections. Finally, we delve into potential strategies for limiting STEC shedding and transmission.
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Affiliation(s)
| | - Pallavi Singh
- Department of Biological Sciences, Northern Illinois University, Dekalb, IL 60115, USA
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Gelalcha BD, Brown SM, Crocker HE, Agga GE, Kerro Dego O. Regulation Mechanisms of Virulence Genes in Enterohemorrhagic Escherichia coli. Foodborne Pathog Dis 2022; 19:598-612. [PMID: 35921067 DOI: 10.1089/fpd.2021.0103] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Enterohemorrhagic Escherichia coli (EHEC) is one of the most common E. coli pathotypes reported to cause several outbreaks of foodborne illnesses. EHEC is a zoonotic pathogen, and ruminants, especially cattle, are considered important reservoirs for the most common EHEC serotype, E. coli O157:H7. Humans are infected indirectly through the consumption of food (milk, meat, leafy vegetables, and fruits) and water contaminated by animal feces or direct contact with carrier animals or humans. E. coli O157:H7 is one of the most frequently reported causes of foodborne illnesses in developed countries. It employs two essential virulence mechanisms to trigger damage to the host. These are the development of attaching and effacing (AE) phenotypes on the intestinal mucosa of the host and the production of Shiga toxin (Stx) that causes hemorrhagic colitis and hemolytic uremic syndrome. The AE phenotype is controlled by the pathogenicity island, the locus of enterocyte effacement (LEE). The induction of both AE and Stx is under strict and highly complex regulatory mechanisms. Thus, a good understanding of these mechanisms, major proteins expressed, and environmental cues involved in the regulation of the expression of the virulence genes is vital to finding a method to control the colonization of reservoir hosts, especially cattle, and disease development in humans. This review is a concise account of the current state of knowledge of virulence gene regulation in the LEE-positive EHEC.
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Affiliation(s)
- Benti D Gelalcha
- Department of Animal Science, The University of Tennessee Institute of Agriculture, Knoxville, Tennessee, USA
| | - Selina M Brown
- Department of Animal Science, The University of Tennessee Institute of Agriculture, Knoxville, Tennessee, USA
| | - Hannah E Crocker
- Department of Animal Science, The University of Tennessee Institute of Agriculture, Knoxville, Tennessee, USA
| | - Getahun E Agga
- Food Animal Environmental Systems Research Unit, Agricultural Research Service, United States Department of Agriculture, Bowling Green, Kentucky, USA
| | - Oudessa Kerro Dego
- Department of Animal Science, The University of Tennessee Institute of Agriculture, Knoxville, Tennessee, USA
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Antaki-Zukoski EM, Li X, Hoar B, Adaska JM, Byrne BA, Atwill ER. Understanding the transmission dynamics of Escherichia coli O157:H7 super-shedding infections in feedlot cattle. PeerJ 2022; 9:e12524. [PMID: 35036119 PMCID: PMC8697766 DOI: 10.7717/peerj.12524] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Accepted: 10/29/2021] [Indexed: 11/20/2022] Open
Abstract
Background The presence of Escherichia coli O157:H7 (E. coli O157:H7) super-shedding cattle in feedlots has the potential to increase the overall number (bio-burden) of E. coli O157:H7 in the environment. It is important to identify factors to reduce the bio-burden of E. coli O157 in feedlots by clarifying practices associated with the occurrence of super-shedders in feedlot cattle. Methods The objective of this study is to (1) identify host, pathogen, and management risk factors associated with naturally infected feedlot cattle excreting high concentrations of E. coli O157:H7 in their feces and (2) to determine whether the ingested dose or the specific strain of E. coli O157:H7 influences a super-shedder infection within experimentally inoculated feedlot cattle. To address this, (1) pen floor fecal samples and herd parameters were collected from four feedlots over a 9-month period, then (2) 6 strains of E. coli O157:H7, 3 strains isolated from normal shedder steers and 3 strains isolated from super-shedder steers, were inoculated into 30 one-year-old feedlot steers. Five steers were assigned to each E. coli O157:H7 strain group and inoculated with targeted numbers of 102, 104, 106, 108, and 1010 CFU of bacteria respectively. Results In the feedlots, prevalence of infection with E. coli O157:H7 for the 890 fecal samples collected was 22.4%, with individual pen prevalence ranging from 0% to 90% and individual feedlot prevalence ranging from 8.4% to 30.2%. Three samples had E. coli O157:H7 levels greater than 104 MPN/g feces, thereby meeting the definition of super-shedder. Lower body weight at entry to the feedlot and higher daily maximum ambient temperature were associated with increased odds of a sample testing positive for E. coli O157:H7. In the experimental inoculation trial, the duration and total environmental shedding load of E. coli O157:H7 suggests that the time post-inoculation and the dose of inoculated E. coli O157:H7 are important while the E. coli O157:H7 strain and shedding characteristic (normal or super-shedder) are not. Discussion Under the conditions of this experiment, super-shedding appears to be the result of cattle ingesting a high dose of any strain of E. coli O157:H7. Therefore strategies that minimize exposure to large numbers of E. coli O157:H7 should be beneficial against the super-shedding of E. coli O157:H7 in feedlots.
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Affiliation(s)
- Elizabeth M Antaki-Zukoski
- Department of Population Health and Reproduction, University of California, Davis, Davis, California, USA.,Western Institute for Food Safety and Security, University of California, Davis, California, USA
| | - Xunde Li
- Department of Population Health and Reproduction, University of California, Davis, Davis, California, USA.,Western Institute for Food Safety and Security, University of California, Davis, California, USA
| | - Bruce Hoar
- College of Agriculture and Natural Resources, University of Wyoming, Laramie, Wyoming, USA
| | - John M Adaska
- Department of Pathology, Microbiology, and Immunology, University of California, Davis, Davis, California, USA.,California Animal Health and Food Safety Laboratory, Tulare Branch, University of California, Tulare, California, USA
| | - Barbara A Byrne
- Department of Pathology, Microbiology, and Immunology, University of California, Davis, Davis, California, USA
| | - Edward R Atwill
- Department of Population Health and Reproduction, University of California, Davis, Davis, California, USA.,Western Institute for Food Safety and Security, University of California, Davis, California, USA
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Evaluation of Cattle for Naturally Colonized Shiga Toxin-Producing Escherichia coli Requires Combinatorial Strategies. Int J Microbiol 2021; 2021:6673202. [PMID: 33868404 PMCID: PMC8032530 DOI: 10.1155/2021/6673202] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2020] [Revised: 02/06/2021] [Accepted: 03/21/2021] [Indexed: 01/01/2023] Open
Abstract
Shiga toxin-producing Escherichia coli (STEC) serogroups O157, O26, O103, O111, O121, O145, and O45 are designated as food adulterants by the U.S. Department of Agriculture-Food Safety and Inspection Service. Cattle are the primary reservoir of these human pathogens. In this study, 59 Angus crossbred heifers were tested specifically for these seven STEC serogroups using a combination of standard culture, serological, PCR, and cell cytotoxicity methods to determine if comparable results would be obtained. At the time of fecal sampling, the animals were approximately 2 years old and weighed 1000–1200 lbs. The diet comprised of 37% ground alfalfa hay, 25% ground Sudan hay, and 38% ground corn supplemented with trace minerals and rumensin with ad libitum access to water. Non-O157 STEC were isolated from 25% (15/59) of the animals tested using a combination of EC broth, CHROMagar STECTM, and Rainbow Agar O157. Interestingly, the O157 serogroup was not isolated from any of the animals. Non-O157 STEC isolates were confirmed to be one of the six adulterant serogroups by serology and/or colony PCR in 10/15 animals with the predominant viable, serogroup being O103. PCR using DNA extracted from feces verified most of the colony PCR results but also identified additional virulence and O-antigen genes from samples with no correlating culture results. Shiga toxin- (Stx-) related cytopathic effects on Vero cells with fecal extracts from 55/59 animals could only be associated with the Stx gene profiles obtained by fecal DNA PCR and not culture results. The differences between culture versus fecal DNA PCR and cytotoxicity assay results suggest that the latter two assays reflect the presence of nonviable STEC or infection with STEC not belonging to the seven adulterant serogroups. This study further supports the use of combinatorial culture, serology, and PCR methods to isolate viable STEC that pose a greater food safety threat.
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Nonfimbrial Adhesin Mutants Reveal Divergent Escherichia coli O157:H7 Adherence Mechanisms on Human and Cattle Epithelial Cells. Int J Microbiol 2021; 2021:8868151. [PMID: 33574851 PMCID: PMC7864753 DOI: 10.1155/2021/8868151] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2020] [Accepted: 01/08/2021] [Indexed: 11/17/2022] Open
Abstract
Shiga toxin-producing, enterohemorrhagic Escherichia coli (EHEC) serotype O157:H7 is a major foodborne pathogen causing symptoms ranging from simple intestinal discomfort to bloody diarrhea and life-threatening hemolytic uremic syndrome in humans. Cattle can be asymptomatically colonized by O157:H7 predominantly at the rectoanal junction (RAJ). Colonization of the RAJ is highly associated with the shedding of O157:H7 in bovine feces. Supershedding (SS) is a phenomenon that has been reported in some cattle that shed more than 104 colony-forming units of O57:H7 per gram of feces, 100–1000 times more or greater than normal shedders. The unique bovine RAJ cell adherence model revealed that O157:H7 employs a LEE-independent mechanism of attachment to one of the RAJ cell types, the squamous epithelial (RSE) cells. Nine nonfimbrial adhesins were selected to determine their role in the characteristic hyperadherent phenotype of SS O157 on bovine RSE cells, in comparison with human HEp-2 cells. A number of single nucleotide polymorphisms (SNPs) were found amongst these nonfimbrial adhesins across a number of SS isolates. In human cells, deletion of yfaL reduced the adherence of both EDL933 and SS17. However, deletion of eae resulted in a significant loss of adherence in SS17 whereas deletion of wzzB and iha in EDL933 resulted in the same loss of adherence to HEp-2 cells. On RSE cells, none of these nonfimbrial deletion mutants were able to alter the adherence phenotype of SS17. In EDL933, deletion of cah resulted in mitigated adherence. Surprisingly, four nonfimbrial adhesin gene deletions were actually able to confer the hyperadherent phenotype on RSE cells. Overall, this study reveals that the contribution of nonfimbrial adhesins to the adherence mechanisms and functions of O157:H7 is both strain and host cell type dependent as well as indicates a possible role of these nonfimbrial adhesins in the SS phenotype exhibited on RSE cells.
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Barth SA, Bauerfeind R, Berens C, Menge C. Shiga Toxin-Producing E. coli in Animals: Detection, Characterization, and Virulence Assessment. Methods Mol Biol 2021; 2291:19-86. [PMID: 33704748 DOI: 10.1007/978-1-0716-1339-9_2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Cattle and other ruminants are primary reservoirs for Shiga toxin-producing Escherichia coli (STEC) strains which have a highly variable, but unpredictable, pathogenic potential for humans. Domestic swine can carry and shed STEC, but only STEC strains producing the Shiga toxin (Stx) 2e variant and causing edema disease in piglets are considered pathogens of veterinary medical interest. In this chapter, we present general diagnostic workflows for sampling livestock animals to assess STEC prevalence, magnitude, and duration of host colonization. This is followed by detailed method protocols for STEC detection and typing at genetic and phenotypic levels to assess the relative virulence exerted by the strains.
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Affiliation(s)
- Stefanie A Barth
- Friedrich-Loeffler-Institut/Federal Research Institute for Animal Health, Institute of Molecular Pathogenesis, Jena, Germany
| | - Rolf Bauerfeind
- Institute for Hygiene and Infectious Diseases of Animals, Justus Liebig University Gießen, Gießen, Germany
| | - Christian Berens
- Friedrich-Loeffler-Institut/Federal Research Institute for Animal Health, Institute of Molecular Pathogenesis, Jena, Germany
| | - Christian Menge
- Friedrich-Loeffler-Institut/Federal Research Institute for Animal Health, Institute of Molecular Pathogenesis, Jena, Germany.
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Dai J, Li C, Cui H, Lin L. Unraveling the anti-bacterial mechanism of Litsea cubeba essential oil against E. coli O157:H7 and its application in vegetable juices. Int J Food Microbiol 2020; 338:108989. [PMID: 33257098 DOI: 10.1016/j.ijfoodmicro.2020.108989] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Revised: 11/16/2020] [Accepted: 11/18/2020] [Indexed: 12/19/2022]
Abstract
Recently, natural essential oils have been extensively studied for anti-bacterial application in foods due to their safety and high biological activity. Herein, Litsea cubeba essential oil (LC-EO) was applied as a natural anti-bacterial agent for exploring its anti-bacterial mechanism against Enterohemorrhagic Escherichia coli O157:H7 (EHEC O157:H7). The LC-EO could effectively inhibit the growth of EHEC O157:H7 and the minimal inhibitory concentration (MIC) was 0.5 mg/mL. In the study of anti-bacterial mechanism, the LC-EO was proved with good membrane penetration ability, which could destroy bacterial cell structure and disorder membrane permeability, thereby causing the leakage of intracellular organic matters. Furthermore, the inhibitory effects of LC-EO on physiological metabolism of EHEC O157:H7, including respiratory metabolism, enzyme activity, the replication of nucleic acid and the transcription level of main virulence genes (stx1, stx2, ehxA, eae), were also demonstrated in this study. Specially, the possible action mechanism of different components of LC-EO on bacterial genetic material was revealed deeply on molecular level by the molecular docking technology. Finally, the results of application evaluation indicated that the addition of LC-EO at MIC in different vegetable juices could maintain anti-bacterial rate above 99.9% for 4 days without remarkable influence on foods sensory quality. The information in this study provides the necessary theoretical foundation for extending the application of LC-EO in food preservation.
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Affiliation(s)
- Jinming Dai
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, China
| | - Changzhu Li
- State Key Laboratory of Utilization of Woody Oil Resource, Hunan Academy of Forestry, Changsha 410007, China
| | - Haiying Cui
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, China.
| | - Lin Lin
- School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, China; State Key Laboratory of Utilization of Woody Oil Resource, Hunan Academy of Forestry, Changsha 410007, China.
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Menge C. The Role of Escherichia coli Shiga Toxins in STEC Colonization of Cattle. Toxins (Basel) 2020; 12:toxins12090607. [PMID: 32967277 PMCID: PMC7551371 DOI: 10.3390/toxins12090607] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 09/16/2020] [Accepted: 09/18/2020] [Indexed: 11/20/2022] Open
Abstract
Many cattle are persistently colonized with Shiga toxin-producing Escherichia coli (STEC) and represent a major source of human infections with human-pathogenic STEC strains (syn. enterohemorrhagic E. coli (EHEC)). Intervention strategies most effectively protecting humans best aim at the limitation of bovine STEC shedding. Mechanisms enabling STEC to persist in cattle are only partialy understood. Cattle were long believed to resist the detrimental effects of Shiga toxins (Stxs), potent cytotoxins acting as principal virulence factors in the pathogenesis of human EHEC-associated diseases. However, work by different groups, summarized in this review, has provided substantial evidence that different types of target cells for Stxs exist in cattle. Peripheral and intestinal lymphocytes express the Stx receptor globotriaosylceramide (Gb3syn. CD77) in vitro and in vivo in an activation-dependent fashion with Stx-binding isoforms expressed predominantly at early stages of the activation process. Subpopulations of colonic epithelial cells and macrophage-like cells, residing in the bovine mucosa in proximity to STEC colonies, are also targeted by Stxs. STEC-inoculated calves are depressed in mounting appropriate cellular immune responses which can be overcome by vaccination of the animals against Stxs early in life before encountering STEC. Considering Stx target cells and the resulting effects of Stxs in cattle, which significantly differ from effects implicated in human disease, may open promising opportunities to improve existing yet insufficient measures to limit STEC carriage and shedding by the principal reservoir host.
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Affiliation(s)
- Christian Menge
- Friedrich-Loeffler-Institut/Federal Research Institute for Animal Health, Institute of Molecular Pathogenesis, D-07743 Jena, Germany
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Sapountzis P, Segura A, Desvaux M, Forano E. An Overview of the Elusive Passenger in the Gastrointestinal Tract of Cattle: The Shiga Toxin Producing Escherichia coli. Microorganisms 2020; 8:microorganisms8060877. [PMID: 32531983 PMCID: PMC7355788 DOI: 10.3390/microorganisms8060877] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 06/05/2020] [Accepted: 06/07/2020] [Indexed: 02/07/2023] Open
Abstract
For approximately 10,000 years, cattle have been our major source of meat and dairy. However, cattle are also a major reservoir for dangerous foodborne pathogens that belong to the Shiga toxin-producing Escherichia coli (STEC) group. Even though STEC infections in humans are rare, they are often lethal, as treatment options are limited. In cattle, STEC infections are typically asymptomatic and STEC is able to survive and persist in the cattle GIT by escaping the immune defenses of the host. Interactions with members of the native gut microbiota can favor or inhibit its persistence in cattle, but research in this direction is still in its infancy. Diet, temperature and season but also industrialized animal husbandry practices have a profound effect on STEC prevalence and the native gut microbiota composition. Thus, exploring the native cattle gut microbiota in depth, its interactions with STEC and the factors that affect them could offer viable solutions against STEC carriage in cattle.
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Affiliation(s)
- Panagiotis Sapountzis
- Université Clermont Auvergne, INRAE, UMR 0454 MEDIS, 63000 Clermont-Ferrand, France; (A.S.); (M.D.); (E.F.)
- Correspondence:
| | - Audrey Segura
- Université Clermont Auvergne, INRAE, UMR 0454 MEDIS, 63000 Clermont-Ferrand, France; (A.S.); (M.D.); (E.F.)
- Chr. Hansen Animal Health & Nutrition, 2970 Hørsholm, Denmark
| | - Mickaël Desvaux
- Université Clermont Auvergne, INRAE, UMR 0454 MEDIS, 63000 Clermont-Ferrand, France; (A.S.); (M.D.); (E.F.)
| | - Evelyne Forano
- Université Clermont Auvergne, INRAE, UMR 0454 MEDIS, 63000 Clermont-Ferrand, France; (A.S.); (M.D.); (E.F.)
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Socially engaged calves are more likely to be colonised by VTEC O157:H7 than individuals showing signs of poor welfare. Sci Rep 2020; 10:6320. [PMID: 32286399 PMCID: PMC7156447 DOI: 10.1038/s41598-020-63186-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Accepted: 03/20/2020] [Indexed: 11/24/2022] Open
Abstract
In cattle herds, the transmission and persistence of VTEC O157:H7 (a serotype of verotoxin-producing Escherichia coli – known for its life threatening complications in humans) is dependent on a small proportion of cattle who become colonised and shed high numbers of the bacteria. Reducing the proportion of these animals is considered key for decreasing the prevalence of VTEC O157:H7. In this study, observations of calf behaviour and animal-based welfare indicators were used to explore individual risk factors and underlying drivers of colonisation in Swedish dairy calves. Interdependencies between variables led to three different approaches being used to visualize and explore the associations. Combining the results of all methods revealed similar patterns and suggest that healthy animals, actively grooming and interacting with others calves in the group have a higher risk of colonisation than small dairy calves in poor condition (diarrhoea, poor ruminal fill, poor body condition score and nasal discharge). This lends no support to the hypothesis that reduced welfare is a risk factor for VTEC O157:H7, but implies that individual differences in calf behaviour affect oral exposure to the bacteria so driving the risk of colonisation. This new finding has important implications for understanding of VTEC O157:H7 transmission within farms.
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Dawson DE, Farthing TS, Sanderson MW, Lanzas C. Transmission on empirical dynamic contact networks is influenced by data processing decisions. Epidemics 2019; 26:32-42. [PMID: 30528207 PMCID: PMC6613374 DOI: 10.1016/j.epidem.2018.08.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Revised: 08/01/2018] [Accepted: 08/27/2018] [Indexed: 11/02/2022] Open
Abstract
Dynamic contact data can be used to inform disease transmission models, providing insight into the dynamics of infectious diseases. Such data often requires extensive processing for use in models or analysis. Therefore, processing decisions can potentially influence the topology of the contact network and the simulated disease transmission dynamics on the network. In this study, we examine how four processing decisions, including temporal sampling window (TSW), spatial threshold of contact (SpTh), minimum contact duration (MCD), and temporal aggregation (daily or hourly) influence the information content of contact data (indicated by changes in entropy) as well as disease transmission model dynamics. We found that changes made to information content by processing decisions translated to significant impacts to the transmission dynamics of disease models using the contact data. In particular, we found that SpTh had the largest independent influence on information content, and that some output metrics (R0, time to peak infection) were more sensitive to changes in information than others (epidemic extent). These findings suggest that insights gained from transmission modeling using dynamic contact data can be influenced by processing decisions alone, emphasizing the need to carefully consideration them prior to using contact-based models to conduct analyses, compare different datasets, or inform policy decisions.
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Affiliation(s)
- Daniel E Dawson
- Department of Pathobiology and Population Health, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, 27606, USA.
| | - Trevor S Farthing
- Department of Pathobiology and Population Health, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, 27606, USA
| | - Michael W Sanderson
- Center for Outcomes Research and Epidemiology, Department of Diagnostic Medicine and Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS, USA
| | - Cristina Lanzas
- Department of Pathobiology and Population Health, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, 27606, USA
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Barrera S, Cardenas P, Graham JP, Trueba G. Changes in dominant Escherichia coli and antimicrobial resistance after 24 hr in fecal matter. Microbiologyopen 2019; 8:e00643. [PMID: 29896865 PMCID: PMC6391265 DOI: 10.1002/mbo3.643] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Revised: 03/05/2018] [Accepted: 03/27/2018] [Indexed: 11/09/2022] Open
Abstract
Intestinal bacteria carry antimicrobial resistance (AMR) genes in mobile genetic elements which have the potential to spread to bacteria in other animal hosts including humans. In fecal matter, Escherichia coli can continue to multiply for 48 hr after being excreted, and in certain environments, E. coli survive long periods of time. It is unclear the extent to which AMR in E. coli changes in the environment outside of its host. In this study, we analyzed changes in the population structure, plasmid content, and AMR patterns of 30 E. coli isolates isolated from 6 chickens (cloacal swabs), and 30 E. coli isolates from fecal samples (from the same 6 chickens) after 24 hr of incubation. Clonality of isolates was screened using the fumC gene sequence and confirmed in a subset of isolates (n = 14) by multi-locus sequence typing. Major shifts in the population structure (i.e., sequence types) and antibiotic resistance patterns were observed among the numerically dominant E. coli isolates after 24 hr. Four E. coli clones isolated from the cloaca swabs and the corresponding fecal samples (after 24 hr incubation) showed different antibiotic resistance patterns. Our study reveals that fecal matter in the environment is an intermediate habitat where rapid and striking changes occur in E. coli populations and antibiotic resistance patterns.
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Affiliation(s)
- Sofía Barrera
- Microbiology InstituteUniversidad San Francisco de QuitoQuitoEcuador
| | - Paul Cardenas
- Microbiology InstituteUniversidad San Francisco de QuitoQuitoEcuador
| | | | - Gabriel Trueba
- Microbiology InstituteUniversidad San Francisco de QuitoQuitoEcuador
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14
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Potential infection of grazing cattle via contaminated water: a theoretical modelling approach. Animal 2019; 13:2052-2059. [PMID: 30614435 DOI: 10.1017/s1751731118003415] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Wastewater discharge and agricultural activities may pose microbial risks to natural water sources. The impact of different sources can be assessed by water quality modelling. The aim of this study was to use hydrological and hydrodynamic models to illustrate the risk of exposing grazing animals to faecal pollutants in natural water sources, using three zoonotic faecal pathogens as model microbes and fictitious pastures in Sweden as examples. Microbial contamination by manure from fertilisation and grazing was modelled by use of a hydrological model (HYPE) and a hydrodynamic model (MIKE 3 FM), and microbial contamination from human wastewater was modelled by application of both models in a backwards process. The faecal pathogens Salmonella spp., verotoxin-producing Escherichia coli O157:H7 (VTEC) and Cryptosporidium parvum were chosen as model organisms. The pathogen loads on arable land and pastures were estimated based on pathogen concentration in cattle faeces, herd prevalence and within-herd prevalence. Contamination from human wastewater discharge was simulated by estimating the number of pathogens required from a fictitious wastewater discharge to reach a concentration high enough to cause infection in cattle using the points on the fictitious pastures as their primary source of drinking water. In the scenarios for pathogens from animal sources, none of the simulated concentrations of salmonella exceeded the concentrations needed to infect adult cattle. For VTEC, most of the simulated concentrations exceeded the concentration needed to infect calves. For C. parvum, all the simulated concentrations exceeded the concentration needed to infect calves. The pathogen loads needed at the release points for human wastewater to achieve infectious doses for cattle were mostly above the potential loads of salmonella and VTEC estimated to be present in a 24-h overflow from a medium-size Swedish wastewater treatment plant, while the required pathogen loads of C. parvum at the release points were below the potential loads of C. parvum in a 24-h wastewater overflow. Most estimates in this study assume a worst-case scenario. Controlling zoonotic infections at herd level prevents environmental contamination and subsequent human exposure. The potential for infection of grazing animals with faecal pathogens has implications for keeping animals on pastures with access to natural water sources. As the infectious dose for most pathogens is more easily reached for calves than for adult animals, and young calves are also the main shedders of C. parvum, keeping young calves on pastures adjacent to natural water sources is best avoided.
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15
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Antaki-Zukoski EM, Li X, Pesavento PA, Nguyen THB, Hoar BR, Atwill ER. Comparative Pathogenicity of Wildlife and Bovine Escherichia coli O157:H7 Strains in Experimentally Inoculated Neonatal Jersey Calves. Vet Sci 2018; 5:E88. [PMID: 30326606 PMCID: PMC6313898 DOI: 10.3390/vetsci5040088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2018] [Revised: 10/11/2018] [Accepted: 10/12/2018] [Indexed: 11/23/2022] Open
Abstract
Shiga toxin-producing Escherichia coli, like E. coli O157:H7, are important human and animal pathogens. Naturally-acquired E. coli O157:H7 infections occur in numerous species but, particularly, cattle have been identified as a significant reservoir for human cases. E. coli O157:H7 are isolated from a number of domestic and wild animals, including rodents that share a living space with cattle. These Shiga toxin-producing E. coli O157:H7 strains can be highly virulent in humans, but little is known about the sequelae of interspecies transfer. In a group of neonatal calves, we determined the differences in colonization patterns and lesions associated with infection using either a wildlife or bovine E. coli O157:H7 strain. In calves challenged with the wildlife E. coli O157:H7 strain, the large (descending) colon was solely colonized, which differed substantially from the calves inoculated with the bovine E. coli O157:H7 strain, where the spiral colon was the principal target of infection. This study also demonstrated that while both interspecies- and intraspecies-derived E. coli O157:H7 can infect young calves, the distribution and severity differs.
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Affiliation(s)
- Elizabeth M Antaki-Zukoski
- Department of Population Health and Reproduction, University of California, Davis, CA 95616, USA.
- Western Institute for Food Safety and Security, University of California, Davis, CA 95618, USA.
| | - Xunde Li
- Department of Population Health and Reproduction, University of California, Davis, CA 95616, USA.
- Western Institute for Food Safety and Security, University of California, Davis, CA 95618, USA.
| | - Patricia A Pesavento
- Department of Pathology, Microbiology, and Immunology, University of California, Davis, CA 95616, USA.
| | - Tran H B Nguyen
- Department of Population Health and Reproduction, University of California, Davis, CA 95616, USA.
| | - Bruce R Hoar
- College of Agriculture and Natural Resources, University of Wyoming, Laramie, WY 82071, USA.
| | - Edward R Atwill
- Department of Population Health and Reproduction, University of California, Davis, CA 95616, USA.
- Western Institute for Food Safety and Security, University of California, Davis, CA 95618, USA.
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16
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Dawson DE, Keung JH, Napoles MG, Vella MR, Chen S, Sanderson MW, Lanzas C. Investigating behavioral drivers of seasonal Shiga-Toxigenic Escherichia Coli (STEC) patterns in grazing cattle using an agent-based model. PLoS One 2018; 13:e0205418. [PMID: 30304002 PMCID: PMC6179278 DOI: 10.1371/journal.pone.0205418] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Accepted: 09/25/2018] [Indexed: 11/18/2022] Open
Abstract
The causes of seasonal variability in pathogen transmission are not well understood, and have not been comprehensively investigated. In an example for enteric pathogens, incidence of Escherichia coli O157 (STEC) colonization in cattle is consistently higher during warmer months compared to cooler months in various cattle production systems. However, actual mechanisms for this seasonality remain elusive. In addition, the influence of host (cattle) behavior on this pattern has not been thoroughly considered. To that end, we constructed a spatially explicit agent-based model that accounted for the effect of temperature fluctuations on cattle behavior (direct contact among cattle and indirect between cattle and environment), as well as its effect on pathogen survival in the environment. We then simulated the model in a factorial approach to evaluate the hypothesis that temperature fluctuations can lead to seasonal STEC transmission dynamics by influencing cattle aggregation, grazing, and drinking behaviors. Simulation results showed that higher temperatures increased the frequency at which cattle aggregated under shade in pasture, resulting in increased direct contact and transmission of STEC between individual cattle, and hence higher incidence over model simulations in the warm season. In contrast, increased drinking behavior during warm season was not an important transmission pathway. Although sensitivity analyses suggested that the relative importance of direct vs. indirect (environmental) pathways depend to upon model parameterization, model simulations indicated that factors influencing cattle aggregation, such as temperature, were likely strong drivers of transmission dynamics of enteric pathogens.
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Affiliation(s)
- Daniel E. Dawson
- Department of Pathobiology and Population Health, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, United States of America
- * E-mail:
| | - Jocelyn H. Keung
- National Institute for Mathematical and Biological Synthesis (NIMBioS), Knoxville, Tennessee, United States of America
| | - Monica G. Napoles
- National Institute for Mathematical and Biological Synthesis (NIMBioS), Knoxville, Tennessee, United States of America
| | - Michael R. Vella
- National Institute for Mathematical and Biological Synthesis (NIMBioS), Knoxville, Tennessee, United States of America
| | - Shi Chen
- Department of Pathobiology and Population Health, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, United States of America
- Department of Public Health Sciences, College of Health and Human Services, University of North Carolina Charlotte, Charlotte, North Carolina, United States of America
| | - Michael W. Sanderson
- Center for Outcomes Research and Epidemiology, Department of Diagnostic Medicine and Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas, United States of America
| | - Cristina Lanzas
- Department of Pathobiology and Population Health, College of Veterinary Medicine, North Carolina State University, Raleigh, North Carolina, United States of America
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17
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Sokolova E, Lindström G, Pers C, Strömqvist J, Lewerin SS, Wahlström H, Sörén K. Water quality modelling: microbial risks associated with manure on pasture and arable land. JOURNAL OF WATER AND HEALTH 2018; 16:549-561. [PMID: 30067238 DOI: 10.2166/wh.2018.278] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
While agricultural activities, such as the application of manure on arable land and animal grazing on pastures, provide economic and environmental benefits, they may also pose microbial risks to water sources. The aim of this paper was to study the microbial fate and transport in an agricultural catchment and recipient water source through further development of the hydrological model HYPE. Hydrological modelling was combined with hydrodynamic modelling to simulate the fate and transport of Salmonella spp., verotoxin-producing Escherichia coli O157:H7 (VTEC) and Cryptosporidium parvum in an agricultural catchment of a drinking water source, Lake Vombsjön, in Sweden. This approach was useful to study the influence of different processes on the pathogen fate and transport, and to interpret the relative changes in the simulated concentrations. Sensitivity analysis indicated that the largest uncertainties in the model were associated with the estimation of pathogen loads, parameterisation of the pathogen processes, and simulation of partitioning between surface runoff and infiltration. The proposed modelling approach is valuable for assessing the relative effect of different risk-reducing interventions.
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Affiliation(s)
- Ekaterina Sokolova
- Department of Architecture and Civil Engineering, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden E-mail:
| | - Göran Lindström
- Research Department, Swedish Meteorological and Hydrological Institute, SE-601 76 Norrköping, Sweden
| | - Charlotta Pers
- Research Department, Swedish Meteorological and Hydrological Institute, SE-601 76 Norrköping, Sweden
| | - Johan Strömqvist
- Research Department, Swedish Meteorological and Hydrological Institute, SE-601 76 Norrköping, Sweden
| | - Susanna Sternberg Lewerin
- Department of Biomedical Sciences and Veterinary Public Health, Swedish University of Agricultural Sciences, Box 7036, SE-750 07 Uppsala, Sweden
| | - Helene Wahlström
- Department of Disease Control and Epidemiology, National Veterinary Institute, SE-751 89 Uppsala, Sweden
| | - Kaisa Sörén
- Department of Disease Control and Epidemiology, National Veterinary Institute, SE-751 89 Uppsala, Sweden
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18
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Browne AS, Midwinter AC, Withers H, Cookson AL, Biggs PJ, Marshall JC, Benschop J, Hathaway S, Haack NA, Akhter RN, French NP. Molecular Epidemiology of Shiga Toxin-Producing Escherichia coli (STEC) on New Zealand Dairy Farms: Application of a Culture-Independent Assay and Whole-Genome Sequencing. Appl Environ Microbiol 2018; 84:e00481-18. [PMID: 29752274 PMCID: PMC6029106 DOI: 10.1128/aem.00481-18] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Accepted: 05/07/2018] [Indexed: 11/20/2022] Open
Abstract
New Zealand has a relatively high incidence of human cases of Shiga toxin-producing Escherichia coli (STEC), with 8.9 STEC cases per 100,000 people reported in 2016. Previous research showed living near cattle and contact with cattle feces as significant risk factors for STEC infections in humans in New Zealand, but infection was not linked to food-associated factors. During the 2014 spring calving season, a random, stratified, cross-sectional study of dairy farms (n = 102) in six regions across New Zealand assessed the prevalence of the "Top 7" STEC bacteria (serogroups O157, O26, O45, O103, O111, O121, and O145) in young calves (n = 1,508), using a culture-independent diagnostic test (PCR/MALDI-TOF). Twenty percent (306/1,508) of calves on 75% (76/102) of dairy farms were positive for at least one of the "Top 7" STEC bacteria. STEC carriage by calves was associated with environmental factors, increased calf age, region, and increased number of calves in a shared calf pen. The intraclass correlation coefficient (ρ) indicated strong clustering of "Top 7" STEC-positive calves for O157, O26, and O45 serogroups within the same pens and farms, indicating that if one calf was positive, others in the same environment were likely to be positive as well. This finding was further evaluated with whole-genome sequencing, which indicated that a single E. coli O26 clonal strain could be found in calves in the same pen or farm, but different strains existed on different farms. This study provides evidence that would be useful for designing on-farm interventions to reduce direct and indirect human exposure to STEC bacteria.IMPORTANCE Cattle are asymptomatic carriers of Shiga toxin-producing E. coli (STEC) bacteria that can cause bloody diarrhea and kidney failure in humans if ingested. New Zealand has relatively high numbers of STEC cases, and contact with cattle feces and living near cattle are risk factors for human infection. This study assessed the national prevalence of STEC in young dairy cattle by randomly selecting 102 farms throughout New Zealand. The study used a molecular laboratory method that has relatively high sensitivity and specificity compared to traditional methods. "Top 7" STEC was found in 20% of calves on 75% of the farms studied, indicating widespread prevalence across the country. By examining the risk factors associated with calf carriage, potential interventions that could decrease the prevalence of "Top 7" STEC bacteria at the farm level were identified, which could benefit both public health and food safety.
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Affiliation(s)
| | | | - Helen Withers
- Ministry of Primary Industries, Wellington, New Zealand
| | - Adrian L Cookson
- EpiLab, Massey University, Palmerston North, New Zealand
- AgResearch Limited, Palmerston North, New Zealand
| | - Patrick J Biggs
- EpiLab, Massey University, Palmerston North, New Zealand
- New Zealand Food Safety Science & Research Centre, Palmerston North, New Zealand
| | | | | | | | | | | | - Nigel P French
- EpiLab, Massey University, Palmerston North, New Zealand
- New Zealand Food Safety Science & Research Centre, Palmerston North, New Zealand
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19
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de Sosa LL, Glanville HC, Marshall MR, Prysor Williams A, Jones DL. Quantifying the contribution of riparian soils to the provision of ecosystem services. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 624:807-819. [PMID: 29272849 DOI: 10.1016/j.scitotenv.2017.12.179] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2017] [Revised: 12/05/2017] [Accepted: 12/16/2017] [Indexed: 06/07/2023]
Abstract
Riparian areas, the interface between land and freshwater ecosystems, are considered to play a pivotal role in the supply of regulating, provisioning, cultural and supporting services. Most previous studies, however, have tended to focus on intensive agricultural systems and only on a single ecosystem function. Here, we present the first study which attempts to assess a wide range of ecological processes involved in the provision of the ecosystem service of water quality regulation across a diverse range of riparian typologies. Specifically, we focus on 1) evaluating the spatial variation in riparian soils properties with respect to distance with the river and soil depth in contrasting habitat types; 2) gaining further insights into the underlying mechanisms of pollutant removal (i.e. pesticide sorption/degradation, denitrification, etc.) by riparian soils; and 3) quantify and evaluate how riparian vegetation across different habitat types contribute to the provision of watercourse shading. All the habitats were present within a single large catchment and included: (i) improved grassland, (ii) unimproved (semi-natural) grassland, (iii) broadleaf woodland, (iv) coniferous woodland, and (iv) mountain, heath and bog. Taking all the data together, the riparian soils could be statistically separated by habitat type, providing evidence that they deliver ecosystem services to differing extents. Overall, however, our findings seem to contradict the general assumption that soils in riparian area are different from neighbouring (non-riparian) areas and that they possess extra functionality in terms of ecosystem service provision. Watercourse shading was highly habitat specific and was maximal in forests (ca. 52% shade cover) in comparison to the other habitat types (7-17%). Our data suggest that the functioning of riparian areas in less intensive agricultural areas, such as those studied here, may be broadly predicted from the surrounding land use, however, further research is required to critically test this across a wider range of ecosystems.
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Affiliation(s)
- Laura L de Sosa
- School of Environment, Natural Resources & Geography, Bangor University, Environment Centre Wales, Deiniol Road, Bangor, Gwynedd LL57 2UW, UK.
| | - Helen C Glanville
- School of Environment, Natural Resources & Geography, Bangor University, Environment Centre Wales, Deiniol Road, Bangor, Gwynedd LL57 2UW, UK; School of Geography, Geology and the Environment, Keele University, Keele, Staffordshire ST5 5BG, UK
| | - Miles R Marshall
- Centre for Ecology and Hydrology, Environment Centre Wales, Deiniol Road, Bangor, Gwynedd LL57 2UW, UK
| | - A Prysor Williams
- School of Environment, Natural Resources & Geography, Bangor University, Environment Centre Wales, Deiniol Road, Bangor, Gwynedd LL57 2UW, UK
| | - Davey L Jones
- School of Environment, Natural Resources & Geography, Bangor University, Environment Centre Wales, Deiniol Road, Bangor, Gwynedd LL57 2UW, UK
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20
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Awosile BB, Smith BA. Risk assessment modelling of fecal shedding caused by extended-spectrum cephalosporin-resistant Escherichia coli transmitted through waste milk fed to dairy pre-weaned calves. J Dairy Sci 2017; 100:9667-9673. [PMID: 28987573 DOI: 10.3168/jds.2017-13196] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Accepted: 08/18/2017] [Indexed: 12/26/2022]
Abstract
Waste milk feeding is a common practice in dairy operations. Regardless of the benefits of this practice to the dairy farmers, concerns from the potential dissemination of antimicrobial-resistant bacteria through the gut and subsequent shedding by calves into the environment are increasing. In this study, we employed Monte Carlo simulation to assess the risk of shedding extended-spectrum cephalosporin-resistant Escherichia coli (ESC-R E. coli) caused by waste milk feeding in pre-weaned calves using an exponential dose-response model fit to data for E. coli O157:H7 in cattle. Data from pertinent studies were included in our model to predict the risk of shedding. The median (5th and 95th percentiles) for the daily risk of shedding ESC-R E. coli by calves fed only contaminated waste milk was predicted to be 2.9 × 10-3 (2.1 × 10-3, 3.7 × 10-3), representing a median daily risk of 29 out of 10,000 calves shedding ESC-R E. coli due to exclusive feeding of waste milk containing ESC-R E. coli. This median value was reduced by 94% when accounting for the proportion of waste milk that does not contain ESC-R E. coli. The overall risk of shedding ESC-R E. coli through the pre-weaning period for farms that feed waste milk to calves was 5.7 × 10-3 (2.4 × 10-3, 1.1 × 10-2), representing 57 out of 10,000 calves. When accounting for the proportion of farms that do not feed waste milk, the pre-weaning period risk was reduced by 23%. By varying the prevalence of ESC-R E. coli in waste milk using values of 3, 1.5, and 1%, the daily risk of shedding decreased by factors of 50, 65, and 82%, respectively, which supports the reduction of contamination or discontinuation of feeding waste milk containing ESC-R E. coli as major mitigation measures to reduce the risk of shedding caused by ingestion of resistant bacteria. It is anticipated that the effects of antimicrobial residues in waste milk, which was not considered herein due to lack of data, would further increase risks. Although waste milk feeding to calves may be economically beneficial to the dairy farmers, there exists the risk of dissemination of ESC-resistant bacteria into the environment.
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Affiliation(s)
- Babafela B Awosile
- Department of Health Management, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, C1A 4P3, Canada.
| | - Ben A Smith
- Public Health Risk Sciences Division, Public Health Agency of Canada, 160 Research Lane, Guelph, Ontario N1G 5B2, Canada
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21
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Lin R, Zhu B, Zhang Y, Bai Y, Zhi F, Long B, Li Y, Wu Y, Wu X, Fan H. Intranasal immunization with novel EspA-Tir-M fusion protein induces protective immunity against enterohemorrhagic Escherichia coli O157:H7 challenge in mice. Microb Pathog 2017; 105:19-24. [DOI: 10.1016/j.micpath.2017.01.062] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2016] [Revised: 01/25/2017] [Accepted: 01/31/2017] [Indexed: 02/06/2023]
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22
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Lin R, Zhang Y, Long B, Li Y, Wu Y, Duan S, Zhu B, Wu X, Fan H. Oral Immunization with Recombinant Lactobacillus acidophilus Expressing espA-Tir-M Confers Protection against Enterohemorrhagic Escherichia coli O157:H7 Challenge in Mice. Front Microbiol 2017; 8:417. [PMID: 28360900 PMCID: PMC5350096 DOI: 10.3389/fmicb.2017.00417] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Accepted: 02/27/2017] [Indexed: 12/15/2022] Open
Abstract
Enterohemorrhagic Escherichia coli O157:H7 (EHEC O157:H7) causes hemorrhagic colitis and the formation of characteristic attaching and effacing (A/E) lesions in humans. Given the severe sequelae of EHEC O157:H7 infection, it is critical to develop effective vaccines for human use. However, for achieving this goal many hurdles need to be addressed, such as the type or subset of antigens, adjuvant, and the delivery route. We developed a candidate vaccine by inserting the bivalent antigen espA-Tir-M composed of espA and the Tir central domain into Lactobacillus acidophilus. The recombinant L. acidophilus (LA-ET) was safe in a cell model and excluded EHEC O157:H7 from LoVo cells at rates of nearly 94 and 60% in exclusion and competition assays, respectively. LA-ET inhibited the induction of A/E lesions by EHEC O157:H7 cells in vitro. Oral immunization with LA-ET induced higher levels of specific mucosal and systemic antibody responses in mice. Moreover, LA-ET enhanced interferon-γ and interleukin-4 and -10 production, which was associated with mixed helper T (Th1/Th2) cell responses, and protected against EHEC O157:H7 colonization and infection in mice at a rate of 80%. Histopathological analyses revealed that orally administered LA-ET reduced or inhibited A/E lesions and toxin-induced systemic injury. These findings demonstrate that LA-ET induces both humoral and cellular immune responses in mice and is therefore a promising vaccine against EHEC O157:H7 infection.
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Affiliation(s)
- Ruqin Lin
- Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University Guangzhou, China
| | - Yiduo Zhang
- Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University Guangzhou, China
| | - Beiguo Long
- Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University Guangzhou, China
| | - Yawen Li
- Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University Guangzhou, China
| | - Yuhua Wu
- Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University Guangzhou, China
| | - Siqin Duan
- Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University Guangzhou, China
| | - Bo Zhu
- The First School of Clinical Medicine, Southern Medical University Guangzhou, China
| | - Xianbo Wu
- Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University Guangzhou, China
| | - Hongying Fan
- Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University Guangzhou, China
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23
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Curli Temper Adherence of Escherichia coli O157:H7 to Squamous Epithelial Cells from the Bovine Recto-Anal Junction in a Strain-Dependent Manner. Appl Environ Microbiol 2016; 83:AEM.02594-16. [PMID: 27742683 DOI: 10.1128/aem.02594-16] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2016] [Accepted: 10/08/2016] [Indexed: 12/16/2022] Open
Abstract
Our recent studies have shown that intimin and the locus of enterocyte effacement-encoded proteins do not play a role in Escherichia coli O157:H7 (O157) adherence to the bovine recto-anal junction squamous epithelial (RSE) cells. To define factors that play a contributory role, we investigated the role of curli, fimbrial adhesins commonly implicated in adherence to various fomites and plant and human epithelial cells, in O157 adherence to RSE cells. Specifically, we examined (i) wild-type strains of O157; (ii) curli variants of O157 strains; (iii) isogenic curli deletion mutants of O157; and (iv) adherence inhibition of O157 using anti-curlin sera. Results of these experiments conducted under stringent conditions suggest that curli do not solely contribute to O157 adherence to RSE cells and in fact demonstrate a modulating effect on O157 adherence to RSE cells in contrast to HEp-2 cells (human epidermoid carcinoma of the larynx cells with HeLa contamination). The absence of curli and presence of blocking anti-curli antibodies enhanced O157-RSE cell interactions among some strains, thus alluding to a spatial, tempering effect of curli on O157 adherence to RSE cells when present. At the same time, the presence or absence of curli did not alter RSE cell adherence patterns of another O157 strain. These observations are at variance with the reported role of curli in O157 adherence to human cell lines such as HEp-2 and need to be factored in when developing anti-adherence modalities for preharvest control of O157 in cattle. IMPORTANCE This study demonstrated that O157 strains interact with epithelial cells in a host-specific manner. The fimbriae/adhesins that are significant for adherence to human cell lines may not have a role or may have a modulating role in O157 adherence to bovine cells. Targeting such adhesins may not prevent O157 attachment to bovine cells but instead may result in improved adherence. Hence, conducting host-specific evaluations is critical when selecting targets for O157 control strategies.
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24
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Hamm K, Barth SA, Stalb S, Geue L, Liebler-Tenorio E, Teifke JP, Lange E, Tauscher K, Kotterba G, Bielaszewska M, Karch H, Menge C. Experimental Infection of Calves with Escherichia coli O104:H4 outbreak strain. Sci Rep 2016; 6:32812. [PMID: 27600997 PMCID: PMC5013450 DOI: 10.1038/srep32812] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Accepted: 08/15/2016] [Indexed: 11/22/2022] Open
Abstract
In 2011, a severe outbreak of hemolytic-uremic syndrome was caused by an unusual, highly virulent enterohemorrhagic E. coli (EHEC) O104:H4 strain, which possessed EHEC virulence traits in the genetic background of human-adapted enteroaggregative E. coli. To determine magnitude of fecal shedding and site of colonization of EHEC O104:H4 in a livestock host, 30 (ten/strain) weaned calves were inoculated with 1010 CFU of EHEC O104:H4, EHEC O157:H7 (positive control) or E. coli strain 123 (negative control) and necropsied (4 or 28 d.p.i.). E. coli O157:H7 was recovered until 28 d.p.i. and O104:H4 until 24 d.p.i. At 4 d.p.i., EHEC O104:H4 was isolated from intestinal content and detected associated with the intestinal mucosa. These results are the first evidence that cattle, the most important EHEC reservoir, can also carry unusual EHEC strains at least transiently, questioning our current understanding of the molecular basis of host adaptation of this important E. coli pathovar.
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Affiliation(s)
- K Hamm
- Friedrich-Loeffler-Institut, Institute of Molecular Pathogenesis, Naumburger Str. 96a, 07743 Jena, Germany
| | - S A Barth
- Friedrich-Loeffler-Institut, Institute of Molecular Pathogenesis, Naumburger Str. 96a, 07743 Jena, Germany
| | - S Stalb
- Friedrich-Loeffler-Institut, Institute of Molecular Pathogenesis, Naumburger Str. 96a, 07743 Jena, Germany
| | - L Geue
- Friedrich-Loeffler-Institut, Institute of Molecular Pathogenesis, Naumburger Str. 96a, 07743 Jena, Germany
| | - E Liebler-Tenorio
- Friedrich-Loeffler-Institut, Institute of Molecular Pathogenesis, Naumburger Str. 96a, 07743 Jena, Germany
| | - J P Teifke
- Friedrich-Loeffler-Institut, Department of Experimental Animal Facilities and Biorisk Management, Südufer 10, 17493 Greifswald - Insel Riems, Germany
| | - E Lange
- Friedrich-Loeffler-Institut, Department of Experimental Animal Facilities and Biorisk Management, Südufer 10, 17493 Greifswald - Insel Riems, Germany
| | - K Tauscher
- Friedrich-Loeffler-Institut, Department of Experimental Animal Facilities and Biorisk Management, Südufer 10, 17493 Greifswald - Insel Riems, Germany
| | - G Kotterba
- Friedrich-Loeffler-Institut, Institute of Infectology, Südufer 10, 17493 Greifswald - Insel Riems, Germany
| | - M Bielaszewska
- Institute of Hygiene, University of Münster, Robert-Koch-Straße 41, 48149 Münster, Germany
| | - H Karch
- Institute of Hygiene, University of Münster, Robert-Koch-Straße 41, 48149 Münster, Germany
| | - C Menge
- Friedrich-Loeffler-Institut, Institute of Molecular Pathogenesis, Naumburger Str. 96a, 07743 Jena, Germany
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Widgren S, Engblom S, Bauer P, Frössling J, Emanuelson U, Lindberg A. Data-driven network modelling of disease transmission using complete population movement data: spread of VTEC O157 in Swedish cattle. Vet Res 2016; 47:81. [PMID: 27515697 PMCID: PMC4982012 DOI: 10.1186/s13567-016-0366-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Accepted: 07/18/2016] [Indexed: 11/10/2022] Open
Abstract
European Union legislation requires member states to keep national databases of all bovine animals. This allows for disease spread models that includes the time-varying contact network and population demographic. However, performing data-driven simulations with a high degree of detail are computationally challenging. We have developed an efficient and flexible discrete-event simulator SimInf for stochastic disease spread modelling that divides work among multiple processors to accelerate the computations. The model integrates disease dynamics as continuous-time Markov chains and livestock data as events. In this study, all Swedish livestock data (births, movements and slaughter) from July 1st 2005 to December 31st 2013 were included in the simulations. Verotoxigenic Escherichia coli O157:H7 (VTEC O157) are capable of causing serious illness in humans. Cattle are considered to be the main reservoir of the bacteria. A better understanding of the epidemiology in the cattle population is necessary to be able to design and deploy targeted measures to reduce the VTEC O157 prevalence and, subsequently, human exposure. To explore the spread of VTEC O157 in the entire Swedish cattle population during the period under study, a within- and between-herd disease spread model was used. Real livestock data was incorporated to model demographics of the population. Cattle were moved between herds according to real movement data. The results showed that the spatial pattern in prevalence may be due to regional differences in livestock movements. However, the movements, births and slaughter of cattle could not explain the temporal pattern of VTEC O157 prevalence in cattle, despite their inherently distinct seasonality.
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Affiliation(s)
- Stefan Widgren
- Department of Clinical Sciences, Swedish University of Agricultural Sciences, 750 07 Uppsala, Sweden
- Department of Disease Control and Epidemiology, National Veterinary Institute, 751 89 Uppsala, Sweden
| | - Stefan Engblom
- Division of Scientific Computing, Department of Information Technology, Uppsala University, 751 05 Uppsala, Sweden
| | - Pavol Bauer
- Division of Scientific Computing, Department of Information Technology, Uppsala University, 751 05 Uppsala, Sweden
| | - Jenny Frössling
- Department of Disease Control and Epidemiology, National Veterinary Institute, 751 89 Uppsala, Sweden
- Department of Animal Environment and Health, Swedish University of Agricultural Sciences, Box 234, 532 23 Skara, Sweden
| | - Ulf Emanuelson
- Department of Clinical Sciences, Swedish University of Agricultural Sciences, 750 07 Uppsala, Sweden
| | - Ann Lindberg
- Department of Disease Control and Epidemiology, National Veterinary Institute, 751 89 Uppsala, Sweden
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26
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Spencer SEF, Besser TE, Cobbold RN, French NP. 'Super' or just 'above average'? Supershedders and the transmission of Escherichia coli O157:H7 among feedlot cattle. J R Soc Interface 2016; 12:0446. [PMID: 26269231 DOI: 10.1098/rsif.2015.0446] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Supershedders have been suggested to be major drivers of transmission of Escherichia coli O157:H7 (E. coli O157:H7) among cattle in feedlot environments, despite our relatively limited knowledge of the processes that govern periods of high shedding within an individual animal. In this study, we attempt a data-driven approach, estimating the key characteristics of high shedding behaviour, including effects on transmission to other animals, directly from a study of natural E. coli O157:H7 infection of cattle in a research feedlot, in order to develop an evidence-based definition of supershedding. In contrast to the hypothesized role of supershedders, we found that high shedding individuals only modestly increased the risk of transmission: individuals shedding over 10(3) cfu g(-1) faeces were estimated to pose a risk of transmission only 2.45 times greater than those shedding below that level. The data suggested that shedding above 10(3) cfu g(-1) faeces was the most appropriate definition of supershedding behaviour and under this definition supershedding was surprisingly common, with an estimated prevalence of 31.3% in colonized individuals. We found no evidence that environmental contamination by faeces of shedding cattle contributed to transmission over timescales longer than 3 days and preliminary evidence that higher stocking density increased the risk of transmission.
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Affiliation(s)
| | - Thomas E Besser
- Department Veterinary Microbiology and Pathology, Washington State University, Pullman, WA 99164, USA
| | - Rowland N Cobbold
- School of Veterinary Science, University of Queensland, Gatton, Queensland, Australia 4343
| | - Nigel P French
- mEpiLab, Infectious Disease Research Centre, Institute of Veterinary Animal and Biomedical Sciences, Massey University, Palmerston North, New Zealand
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Contributions of EspA Filaments and Curli Fimbriae in Cellular Adherence and Biofilm Formation of Enterohemorrhagic Escherichia coli O157:H7. PLoS One 2016; 11:e0149745. [PMID: 26900701 PMCID: PMC4764202 DOI: 10.1371/journal.pone.0149745] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Accepted: 02/04/2016] [Indexed: 12/14/2022] Open
Abstract
In Escherichia coli O157:H7 (O157), the filamentous structure of the type III secretion system is produced from the polymerization of the EspA protein. EspA filaments are essential for O157 adherence to epithelial cells. In previous studies, we demonstrated that O157 hha deletion mutants showed increased adherence to HEp-2 cells and produced abundant biofilms. Transcriptional analysis revealed increased expression of espA as well as the csgA gene, which encodes curli fimbriae that are essential for biofilm formation. In the present study, we constructed hha espA, hha csgA, and hha csgA espA deletion mutants to determine the relative importance of EspA and CsgA in O157 adherence to HEp-2 cells and biofilm formation. In vitro adherence assays, conducted at 37°C in a tissue culture medium containing 0.1% glucose, showed that HEp-2 cell adherence required EspA because hha espA and hha csgA espA mutants adhered to HEp-2 cells at higher levels only when complemented with an espA-expressing plasmid. Biofilm assays performed at 28°C in a medium lacking glucose showed dependency of biofilm formation on CsgA; however EspA was not produced under these conditions. Despite production of detectable levels of EspA at 37°C in media supplemented with 0.1% glucose, the biofilm formation occurred independent of EspA. These results indicate dependency of O157 adherence to epithelial cells on EspA filaments, while CsgA promoted biofilm formation under conditions mimicking those found in the environment (low temperature with nutrient limitations) and in the digestive tract of an host animal (higher temperature and low levels of glucose).
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Sheng H, Shringi S, Baker KNK, Minnich SA, Hovde CJ, Besser TE. Standardized Escherichia coli O157:H7 Exposure Studies in Cattle Provide Evidence that Bovine Factors Do Not Drive Increased Summertime Colonization. Appl Environ Microbiol 2016; 82:964-71. [PMID: 26607594 PMCID: PMC4725274 DOI: 10.1128/aem.02839-15] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Accepted: 11/17/2015] [Indexed: 12/11/2022] Open
Abstract
The increased summertime prevalence of cattle carriage of enterohemorrhagic Shiga toxin-producing Escherichia coli O157:H7 (STEC O157) is associated with the increased summertime incidence of human infection. The mechanism driving the seasonality of STEC O157 carriage among cattle is unknown. We conducted experimental challenge trials to distinguish whether factors extrinsic or intrinsic to cattle underlie the seasonality of STEC O157 colonization. Holstein steers (n = 20) exposed to ambient environmental conditions were challenged with a standardized pool of STEC O157 strains four times at 6-month intervals. The densities and durations of rectoanal junction mucosa (RAJ) colonization with STEC O157 were compared by season (winter versus summer), dose (10(9) CFU versus 10(7) CFU), and route of challenge (oral versus rectal). Following summer challenges, the RAJ STEC O157 colonization density was significantly lower (P = 0.016) and the duration was shorter (P = 0.052) than for winter challenges, a seasonal pattern opposite to that observed naturally. Colonization was unaffected by the challenge route, indicating that passage through the gastrointestinal microbiome did not significantly affect the infectious dose to the RAJ. A 2-log reduction of the challenge doses in the second-year trials was accompanied by similarly reduced RAJ colonization in both seasons (P < 0.001). These results refute the hypothesis that cattle are predisposed to STEC O157 colonization during the summer months, either due to intrinsic factors or indirectly due to gastrointestinal tract microbiome effects. Instead, the data support the hypothesis that the increased summertime STEC O157 colonization results from increased seasonal oral exposure to this pathogen.
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Affiliation(s)
- Haiqing Sheng
- Bi-state School of Food Science, University of Idaho, Moscow, Idaho, USA
| | - Smriti Shringi
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, Washington, USA
| | - Katherine N K Baker
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, Washington, USA
| | - Scott A Minnich
- Bi-state School of Food Science, University of Idaho, Moscow, Idaho, USA
| | - Carolyn J Hovde
- Bi-state School of Food Science, University of Idaho, Moscow, Idaho, USA
| | - Thomas E Besser
- Department of Veterinary Microbiology and Pathology, Washington State University, Pullman, Washington, USA
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29
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Schmidt CE, Shringi S, Besser TE. Protozoan Predation of Escherichia coli O157:H7 Is Unaffected by the Carriage of Shiga Toxin-Encoding Bacteriophages. PLoS One 2016; 11:e0147270. [PMID: 26824472 PMCID: PMC4732659 DOI: 10.1371/journal.pone.0147270] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2014] [Accepted: 12/25/2015] [Indexed: 12/28/2022] Open
Abstract
Escherichia coli O157:H7 is a food-borne bacterium that causes hemorrhagic diarrhea and hemolytic uremic syndrome in humans. While cattle are a known source of E. coli O157:H7 exposure resulting in human infection, environmental reservoirs may also be important sources of infection for both cattle and humans. Bacteriophage-encoded Shiga toxins (Stx) carried by E. coli O157:H7 may provide a selective advantage for survival of these bacteria in the environment, possibly through their toxic effects on grazing protozoa. To determine Stx effects on protozoan grazing, we co-cultured Paramecium caudatum, a common ciliate protozoon in cattle water sources, with multiple strains of Shiga-toxigenic E. coli O157:H7 and non-Shiga toxigenic cattle commensal E. coli. Over three days at ambient laboratory temperature, P. caudatum consistently reduced both E. coli O157:H7 and non-Shiga toxigenic E. coli populations by 1-3 log cfu. Furthermore, a wild-type strain of Shiga-toxigenic E. coli O157:H7 (EDL933) and isogenic mutants lacking the A subunit of Stx 2a, the entire Stx 2a-encoding bacteriophage, and/or the entire Stx 1-encoding bacteriophage were grazed with similar efficacy by both P. caudatum and Tetrahymena pyriformis (another ciliate protozoon). Therefore, our data provided no evidence of a protective effect of either Stx or the products of other bacteriophage genes on protozoan predation of E. coli. Further research is necessary to determine if the grazing activity of naturally-occurring protozoa in cattle water troughs can serve to decrease cattle exposure to E. coli O157:H7 and other Shiga-toxigenic E. coli.
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Affiliation(s)
- Carrie E. Schmidt
- Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, Washington, United States of America
- * E-mail:
| | - Smriti Shringi
- Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, Washington, United States of America
| | - Thomas E. Besser
- Department of Veterinary Microbiology and Pathology, College of Veterinary Medicine, Washington State University, Pullman, Washington, United States of America
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30
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Williams KJ, Ward MP, Dhungyel OP. Longitudinal study of Escherichia coli O157 shedding and super shedding in dairy heifers. J Food Prot 2015; 78:636-42. [PMID: 25836386 DOI: 10.4315/0362-028x.jfp-14-455] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A longitudinal study was conducted to assess the methods available for detection of Escherichia coli O157 and to investigate the prevalence and occurrence of long-term shedding and super shedding in a cohort of Australian dairy heifers. Samples were obtained at approximately weekly intervals from heifers at pasture under normal management systems. Selective sampling techniques were used with the aim of identifying heifers with a higher probability of shedding or super shedding. Rectoanal mucosal swabs (RAMS) and fecal samples were obtained from each heifer. Direct culture of feces was used for detection and enumeration. Feces and RAMS were tested by enrichment culture. Selected samples were further tested retrospectively by immunomagnetic separation of enriched samples. Of 784 samples obtained, 154 (19.6%) were detected as positive using culture methods. Adjusting for selective sampling, the prevalence was 71 (15.6%) of 454. In total, 66 samples were detected as positive at >10(2) CFU/g of which 8 were >10(4) CFU/g and classed as super shedding. A significant difference was observed in detection by enriched culture of RAMS and feces. Dairy heifers within this cohort exhibited variable E. coli O157 shedding, consistent with previous estimates of shedding. Super shedding was detected at a low frequency and inconsistently from individual heifers. All detection methods identified some samples as positive that were not detected by any other method, indicating that the testing methods used will influence survey results.
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Affiliation(s)
- K J Williams
- Faculty of Veterinary Science, University of Sydney, 425 Werombi Road, Camden, New South Wales, 2570, Australia.
| | - M P Ward
- Faculty of Veterinary Science, University of Sydney, 425 Werombi Road, Camden, New South Wales, 2570, Australia
| | - O P Dhungyel
- Faculty of Veterinary Science, University of Sydney, 425 Werombi Road, Camden, New South Wales, 2570, Australia
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31
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Daily variations in Escherichia coli O157 shedding patterns in a cohort of dairy heifers at pasture. Epidemiol Infect 2014; 143:1388-97. [PMID: 25234098 DOI: 10.1017/s0950268814002374] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Escherichia coli O157 is a human pathogen carried asymptomatically by cattle and shed in their faeces. Infection can occur from the consumption of contaminated beef or by direct contact. Large variations of E. coli O157 shedding in cattle exist and vary in the number of cattle positive for E. coli O157 and the amount of bacteria (c.f.u./g faeces) shed by positive animals. To investigate E. coli O157 shedding and super-shedding (>104 c.f.u./g) we used daily sampling over two 8-day periods; in January 2013 (n = 12) and February 2013 (n = 21). Samples were tested by direct faecal culture for enumeration and by immunomagnetic separation to detect lower levels of shedding. We identified three patterns of shedding, similar to previously observed descriptions: intermittent, transient and consistent. The most commonly observed pattern was intermittent shedding and variation in the level of shedding could be large. This extreme variation is demonstrated by a heifer from which E. coli O157 could be not detected one day, was super-shedding E. coli O157 the next and was detected as shedding >100 c.f.u./g the following day. Recto-anal mucosal swab testing did not predict super-shedding in this cohort of heifers. The variable individual patterns of shedding suggest that a common mechanism of infection may not operate within such a herd when considering previously described patterns and the inferred mechanisms. The sporadic and intermittent nature of shedding is a challenge to identifying risk factors and potential intervention strategies.
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Abstract
ABSTRACT
Shiga toxin-producing
Escherichia coli
(STEC) strains have been detected in a wide diversity of mammals, birds, fish, and several insects. Carriage by most animals is asymptomatic, thus allowing for dissemination of the bacterium in the environment without detection. Replication of the organism may occur in the gastrointestinal tract of some animals, notably ruminants. Carriage may also be passive or transient, without significant amplification of bacterial numbers while in the animal host. Animals may be classified as reservoir species, spillover hosts, or dead-end hosts. This classification is based on the animal's ability to (i) transmit STEC to other animal species and (ii) maintain STEC infection in the absence of continuous exposure. Animal reservoirs are able to maintain STEC infections in the absence of continuous STEC exposure and transmit infection to other species. Spillover hosts, although capable of transmitting STEC to other animals, are unable to maintain infection in the absence of repeated exposure. The large diversity of reservoir and spillover host species and the survival of the organism in environmental niches result in complex pathways of transmission that are difficult to interrupt.
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Blyton MDJ, Banks SC, Peakall R, Lindenmayer DB, Gordon DM. Not all types of host contacts are equal when it comes to E. coli transmission. Ecol Lett 2014; 17:970-8. [PMID: 24861219 DOI: 10.1111/ele.12300] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Revised: 01/07/2014] [Accepted: 04/28/2014] [Indexed: 11/28/2022]
Abstract
The specific processes that facilitate pathogen transmission are poorly understood, particularly for wild animal populations. A major impediment for investigating transmission pathways is the need for simultaneous information on host contacts and pathogen transfer. In this study, we used commensal Escherichia coli strains as a model system for gastrointestinal pathogens. We combined strain-sharing information with detailed host contact data to investigate transmission routes in mountain brushtail possums. Despite E. coli being transmitted via the faecal-oral route, we revealed that, strain-sharing among possums was better explained by host contacts than spatial proximity. Furthermore, and unexpectedly, strain-sharing was more strongly associated with the duration of brief nocturnal associations than day-long den-sharing. Thus, the most cryptic and difficult associations to measure were the most relevant connections for the transmission of this symbiont. We predict that future studies that employ similar approaches will reveal the importance of previously overlooked associations as key transmission pathways.
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Affiliation(s)
- Michaela D J Blyton
- Evolution, Ecology and Genetics, Research School of Biology, The Australian National University, Canberra, ACT, 0200, Australia; The Fenner School of Environment and Society, The Australian National University, Canberra, ACT, 0200, Australia
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34
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Juneja VK, Mukhopadhyay S, Ukuku D, Hwang CA, Wu VCH, Thippareddi H. Interactive effects of temperature, pH, and water activity on the growth kinetics of Shiga toxin-producing Escherichia coli O104:H4 3. J Food Prot 2014; 77:706-12. [PMID: 25198132 DOI: 10.4315/0362-028x.jfp-13-387] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The risk of non-O157 Shiga toxin-producing Escherichia coli strains has become a growing public health concern. Several studies characterized the behavior of E. coli O157:H7; however, no reports on the influence of multiple factors on E. coli O104:H4 are available. This study examined the effects and interactions of temperature (7 to 46°C), pH (4.5 to 8.5), and water activity (aw ; 0.95 to 0.99) on the growth kinetics of E. coli O104:H4 and developed predictive models to estimate its growth potential in foods. Growth kinetics studies for each of the 23 variable combinations from a central composite design were performed. Growth data were used to obtain the lag phase duration (LPD), exponential growth rate, generation time, and maximum population density (MPD). These growth parameters as a function of temperature, pH, and aw as controlling factors were analyzed to generate second-order response surface models. The results indicate that the observed MPD was dependent on the pH, aw, and temperature of the growth medium. Increasing temperature resulted in a concomitant decrease in LPD. Regression analysis suggests that temperature, pH, and aw significantly affect the LPD, exponential growth rate, generation time, and MPD of E. coli O104:H4. A comparison between the observed values and those of E. coli O157:H7 predictions obtained by using the U. S. Department of Agriculture Pathogen Modeling Program indicated that E. coli O104:H4 grows faster than E. coli O157:H7. The developed models were validated with alfalfa and broccoli sprouts. These models will provide risk assessors and food safety managers a rapid means of estimating the likelihood that the pathogen, if present, would grow in response to the interaction of the three variables assessed.
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35
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Zhao Y, Aarnink AJA, De Jong MCM, Groot Koerkamp PWG. Airborne Microorganisms From Livestock Production Systems and Their Relation to Dust. CRITICAL REVIEWS IN ENVIRONMENTAL SCIENCE AND TECHNOLOGY 2014; 44:1071-1128. [PMID: 32288664 PMCID: PMC7113898 DOI: 10.1080/10643389.2012.746064] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Large amounts of airborne microorganisms are emitted from livestock production. These emitted microorganisms may associate with dust, and are suspected to pose a risk of airborne infection to humans in vicinity and to animals on other farms. However, the extent to which airborne transmission may play a role in the epidemic, and how dust acts as a carrier of microorganisms in the transmission processes is unknown. The authors present the current knowledge of the entire process of airborne transmission of microorganisms-from suspension and transportation until deposition and infection-and their relation to dust. The sampling and the mitigation techniques of airborne microorganisms and dust in livestock production systems are introduced as well.
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Affiliation(s)
- Yang Zhao
- Wageningen UR Livestock Research, Lelystad, the Netherlands
- Department of Agricultural and Biosystems EngineeringIowa State University, Ames, IA, USA
| | | | - Mart C. M. De Jong
- Quantitative Veterinary Epidemiology, Wageningen University, Wageningen, the Netherlands
| | - Peter W. G. Groot Koerkamp
- Wageningen UR Livestock Research, Lelystad, the Netherlands
- Farm Technology Group, Wageningen University, Wageningen, the Netherlands
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Transmission of Escherichia coli O157:H7 in cattle is influenced by the level of environmental contamination. Epidemiol Infect 2014; 143:274-87. [PMID: 24731271 PMCID: PMC4301210 DOI: 10.1017/s0950268814000867] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
A pen infection-transmission experiment was conducted to elucidate the role of pathogen strain and environmental contamination in transmission of Escherichia coli O157:H7 (ECO157) in cattle. Five steers were inoculated with a three-strain mixture of ECO157 and joined with five susceptible steers in each of two experimental replicates. Faecal and environmental samples were monitored for ECO157 presence over 30 days. One ECO157 strain did not spread. Transmission rates for the other two strains were estimated using a generalized linear model developed based on a modified ‘Susceptible–Infectious–Susceptible’ mathematical model. Transmission rates estimated for the two strains (0·11 and 0·14) were similar. However, the rates significantly (P = 0·0006) increased 1·5 times for every 1-unit increase in the level of environmental contamination measured as log10 c.f.u. Depending on the level of environmental contamination, the estimated basic reproduction numbers varied from <1 to 8. The findings indicate the importance of on-farm measures to reduce environmental contamination for ECO157 control in cattle that should be validated under field conditions.
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37
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Kim SA, Kim NH, Lee SH, Hwang IG, Rhee MS. Survival of foodborne pathogenic bacteria (Bacillus cereus, Escherichia coli O157:H7, Salmonella enterica serovar Typhimurium, Staphylococcus aureus, and Listeria monocytogenes) and Bacillus cereus spores in fermented alcoholic beverages (beer and refined rice wine). J Food Prot 2014; 77:419-26. [PMID: 24674433 DOI: 10.4315/0362-028x.jfp-13-234] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Only limited information is available on the microbiological safety of fermented alcoholic beverages because it is still a common belief that such beverages do not provide a favorable environment for bacterial growth and survival. Thus, in this study, we examined the survival of major foodborne pathogens and spores in fermented alcoholic beverages. Foodborne pathogens (Bacillus cereus, Escherichia coli O157:H7, Listeria monocytogenes, Salmonella enterica serovar Typhimurium, and Staphylococcus aureus) and B. cereus spores (initial population, 3 to 4 log CFU/ml) were inoculated separately into three types of beer and refined rice wine, which were then stored at 5 and 22°C. Bacterial counts were assayed periodically for up to 28 days. Vegetative B. cereus counts decreased rapidly, whereas B. cereus spore counts remained constant (P > 0.05) for a long period of time in all beverages. Vegetative B. cereus cells formed spores in beer at 5 and 22°C, and the spores survived for long periods. Among vegetative cells, E. coli O157:H7 had the highest survival (only 1.49 to 1.56 log reduction during 28 days in beer at 5°C). Beer and refined rice wine supported microbial survival from several days to several weeks. Our results appear to contradict the common belief that pathogens cannot survive in alcoholic beverages. Long-term survival of pathogens (especially B. cereus and E. coli O157:H7) in beer and refined rice wine should be taken into consideration by the manufacturers of these beverages. This study provides basic information that should help further research into microbial survival in alcoholic beverages and increase the microbiological safety regulation of fermented alcoholic beverages.
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Affiliation(s)
- S A Kim
- Department of Food Bioscience and Technology, College of Life Sciences and Biotechnology, Korea University, Seoul 136-713, South Korea
| | - N H Kim
- Department of Food Bioscience and Technology, College of Life Sciences and Biotechnology, Korea University, Seoul 136-713, South Korea
| | - S H Lee
- Food Microbiology Division, Ministry of Food and Drug Safety, Cheongwon-gun, 363-951, South Korea
| | - I G Hwang
- Food Standardization Division, Ministry of Food and Drug Safety, Cheongwon-gun, 363-951, South Korea
| | - M S Rhee
- Department of Food Bioscience and Technology, College of Life Sciences and Biotechnology, Korea University, Seoul 136-713, South Korea.
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Smith DR. Cattle Production Systems: Ecology of Existing and Emerging Escherichia coli Types Related to Foodborne Illness. Annu Rev Anim Biosci 2014; 2:445-68. [DOI: 10.1146/annurev-animal-022513-114122] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Shiga toxin–producing Escherichia coli (STEC), particularly STEC O157, cause rare but potentially serious human infections. Infection with STEC occurs by fecal-oral transmission, most commonly through food. Cattle are the most important reservoir for human STEC exposure, and efforts to control the flow of STEC through beef processing have reduced rates of human illness. However, further reduction in human incidence of STEC may require control of the pathogen in cattle populations. The ecology of STEC in cattle production systems is complex and explained by factors that favor (a) colonization in the gut, (b) survival in the environment, and (c) ingestion by another cattle host. Although nature creates seasonal environmental conditions that do not favor STEC transmission in cattle, human efforts to control STEC by environmental manipulation have not succeeded. Vaccines and direct-fed microbial products have reduced the carriage of STEC by cattle, and other interventions are under investigation.
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Affiliation(s)
- David R. Smith
- Mississippi State University College of Veterinary Medicine, Mississippi State, Mississippi 39762-6100
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A review of factors that affect transmission and survival of verocytotoxigenic Escherichia coli in the European farm to fork beef chain. Meat Sci 2014; 97:375-83. [PMID: 24548772 DOI: 10.1016/j.meatsci.2014.01.009] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2013] [Revised: 01/13/2014] [Accepted: 01/16/2014] [Indexed: 11/21/2022]
Abstract
Verocytotoxigenic Escherichia coli (VTEC) are a significant foodborne public health hazard in Europe, where most human infections are associated with six serogroups (O157, O26, O103, O145, O111 and O104). With the exception of O104, these serogroups are associated with bovine animals and beef products. This paper reviews our current knowledge of VTEC in the beef chain focusing on transmission and the factors which impact on survival from the farm through transport, lairage, slaughter, dressing, processing and distribution, in the context of the European beef industry. It provides new information on beef farm and animal hide prevalence, distribution and virulence factors as well as pre-chilled carcass and ground beef prevalence, generated by the recently completed EU Framework research project, ProSafeBeef. In the concluding section, emerging issues and data gaps are addressed with a view to increasing our understanding of this pathogen and developing new thinking on detection and control.
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40
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Baines D, Erb S. Characterization of Shiga toxin - producing Escherichia coli infections in beef feeder calves and the effectiveness of a prebiotic in alleviating Shiga toxin - producing Escherichia coli infections. Ir Vet J 2013; 66:17. [PMID: 24090455 PMCID: PMC3850653 DOI: 10.1186/2046-0481-66-17] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2012] [Accepted: 09/16/2013] [Indexed: 11/18/2022] Open
Abstract
Background In the less-sensitive mouse model, Shiga toxin-producing Escherichia coli (STEC) challenges result in shedding that reflect the amount of infection and the expression of virulence factors such as Shiga toxins (Stx). The purpose of this study was to characterize the contribution of STEC diversity and Stx expression to shedding in beef feeder calves and to evaluate the effectiveness of a prebiotic, Celmanax®, to alleviate STEC shedding. Fecal samples were collected from calves at entry and after 35 days in the feedlot in spring and summer. STECs were evaluated using selective media, biochemical profile, serotyping and Stx detection. Statistical analysis was performed using repeated measures ANOVA and logistic regression. Results At entry, non-O157 STEC were dominant in shedding calves. In spring, 21%, 14% and 14% of calves acquired O157, non-O157 and mixed STEC infections, respectively. In contrast, 45%, 48% and 46% of calves in summer acquired O157, non-O157 and mixed STEC infections, respectively. Treatment with a prebiotic, Celmanax®, in spring significantly reduced 50% of the O157 STEC infections, 50% of the non-O157 STEC infections and 36% of the STEC co-infections (P = 0.037). In summer, there was no significant effect of the prebiotic on STEC infections. The amount of shedding at entry was significantly related to the number and type of STECs present and Stx expression (r2 = 0.82). The same relationship was found for shedding at day 35 (r2 = 0.85), but it was also related to the number and type of STECs present at entry. Stx - producing STEC infections resulted in 100 to 1000 × higher shedding in calves compared with Stx-negative STECs. Conclusions STEC infections in beef feeder calves reflect the number and type of STECs involved in the infection and STEC expression of Stx. Application of Celmanax® reduced O157 and non-O157 STEC shedding by calves but further research is required to determine appropriate dosages to manage STEC infections.
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Affiliation(s)
- Danica Baines
- Agriculture and Agri-Food Canada, Lethbridge Research Centre, 5403 1 Avenue South, P,O, Box 3000, T1J 4B1 Lethbridge, AB, Canada.
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41
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VanderWaal KL, Atwill ER, Isbell LA, McCowan B. Linking social and pathogen transmission networks using microbial genetics in giraffe (Giraffa camelopardalis). J Anim Ecol 2013; 83:406-14. [PMID: 24117416 DOI: 10.1111/1365-2656.12137] [Citation(s) in RCA: 158] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2013] [Accepted: 08/28/2013] [Indexed: 01/10/2023]
Abstract
Although network analysis has drawn considerable attention as a promising tool for disease ecology, empirical research has been hindered by limitations in detecting the occurrence of pathogen transmission (who transmitted to whom) within social networks. Using a novel approach, we utilize the genetics of a diverse microbe, Escherichia coli, to infer where direct or indirect transmission has occurred and use these data to construct transmission networks for a wild giraffe population (Giraffe camelopardalis). Individuals were considered to be a part of the same transmission chain and were interlinked in the transmission network if they shared genetic subtypes of E. coli. By using microbial genetics to quantify who transmits to whom independently from the behavioural data on who is in contact with whom, we were able to directly investigate how the structure of contact networks influences the structure of the transmission network. To distinguish between the effects of social and environmental contact on transmission dynamics, the transmission network was compared with two separate contact networks defined from the behavioural data: a social network based on association patterns, and a spatial network based on patterns of home-range overlap among individuals. We found that links in the transmission network were more likely to occur between individuals that were strongly linked in the social network. Furthermore, individuals that had more numerous connections or that occupied 'bottleneck' positions in the social network tended to occupy similar positions in the transmission network. No similar correlations were observed between the spatial and transmission networks. This indicates that an individual's social network position is predictive of transmission network position, which has implications for identifying individuals that function as super-spreaders or transmission bottlenecks in the population. These results emphasize the importance of association patterns in understanding transmission dynamics, even for environmentally transmitted microbes like E. coli. This study is the first to use microbial genetics to construct and analyse transmission networks in a wildlife population and highlights the potential utility of an approach integrating microbial genetics with network analysis.
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Affiliation(s)
- Kimberly L VanderWaal
- Animal Behavior Graduate Group, University of California, Shields Avenue, Davis, CA, 95616, USA.,International Institute for Human-Animal Networks, University of California, Davis, CA, USA.,Wangari Maathai Institute for Peace and Environmental Studies, University of Nairobi, PO Box 29053-00635, Nairobi, Kenya
| | - Edward R Atwill
- Department of Population Health and Reproduction, School of Veterinary Medicine, University of California, Davis, CA, USA.,Western Institute for Food Safety and Security, University of California, Davis, CA, USA
| | - Lynne A Isbell
- Animal Behavior Graduate Group, University of California, Shields Avenue, Davis, CA, 95616, USA.,Department of Anthropology, University of California, Davis, CA, USA
| | - Brenda McCowan
- Animal Behavior Graduate Group, University of California, Shields Avenue, Davis, CA, 95616, USA.,International Institute for Human-Animal Networks, University of California, Davis, CA, USA.,Department of Population Health and Reproduction, School of Veterinary Medicine, University of California, Davis, CA, USA
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42
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Scientific Opinion on the public health hazards to be covered by inspection of meat (bovine animals). EFSA J 2013. [DOI: 10.2903/j.efsa.2013.3266] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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Abstract
A risk ranking process identified Toxoplasma gondii and pathogenic verocytotoxin-producing Escherichia coli (VTEC) as the most relevant biological hazards for meat inspection of sheep and goats. As these are not detected by traditional meat inspection, a meat safety assurance system using risk-based interventions was proposed. Further studies are required on T. gondii and pathogenic VTEC. If new information confirms these hazards as a high risk to public health from meat from sheep or goats, setting targets at carcass level should be considered. Other elements of the system are risk-categorisation of flocks/herds based on improved Food Chain Information (FCI), classification of abattoirs according to their capability to reduce faecal contamination, and use of improved process hygiene criteria. It is proposed to omit palpation and incision from post-mortem inspection in animals subjected to routine slaughter. For chemical hazards, dioxins and dioxin-like polychlorinated biphenyls were ranked as being of high potential concern. Monitoring programmes for chemical hazards should be more flexible and based on the risk of occurrence, taking into account FCI, which should be expanded to reflect the extensive production systems used, and the ranking of chemical substances, which should be regularly updated and include new hazards. Control programmes across the food chain, national residue control plans, feed control and monitoring of environmental contaminants should be better integrated. Meat inspection is a valuable tool for surveillance and monitoring of animal health and welfare conditions. Omission of palpation and incision would reduce detection effectiveness for tuberculosis and fasciolosis at animal level. Surveillance of tuberculosis at the slaughterhouse in small ruminants should be improved and encouraged, as this is in practice the only surveillance system available. Extended use of FCI could compensate for some, but not all, the information on animal health and welfare lost if only visual post-mortem inspection is applied.
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44
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Etcheverría AI, Padola NL. Shiga toxin-producing Escherichia coli: factors involved in virulence and cattle colonization. Virulence 2013; 4:366-72. [PMID: 23624795 PMCID: PMC3714128 DOI: 10.4161/viru.24642] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Shiga toxin-producing Escherichia coli (STEC) cause hemorrhagic colitis (HC) and hemolytic uremic syndrome (HUS) in humans. Outbreaks are linked to bovine food sources. STEC O157:H7 has been responsible for the most severe outbreaks worldwide. However, non-O157 serotypes have emerged as important enteric pathogens in several countries. The main virulence factor of STEC is the production of Shiga toxins 1 and 2. Additional virulence markers are a plasmid-encoded enterohemolysin (ehxA), an autoagglutinating adhesin (Saa), a catalase-peroxidase (katP), an extracellular serine protease (espP), a zinc metalloprotease (stcE), a subtilase cytotoxin (subAB), among others. Other virulence factors are intimin and adhesins that had a roll in the adherence of STEC to bovine colon. This review focuses on the virulence traits of STEC and especially on those related to the adhesion to bovine colon. The known of the interaction between STEC and the bovine host is crucial to develop strategies to control cattle colonization.
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Affiliation(s)
- Analía Inés Etcheverría
- Laboratorio de Imunoquímica y Biotecnología, Centro de Investigación Veterinaria de Tandil (CIVETAN), CONICET-CICPBA, Facultad de Ciencias Veterinarias, UNCPBA, Tandil, Argentina.
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45
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Kulow MJ, Gonzales TK, Pertzborn KM, Dahm J, Miller BA, Park D, Gautam R, Kaspar CW, Ivanek R, Döpfer D. Differences in colonization and shedding patterns after oral challenge of cattle with three Escherichia coli O157:H7 strains. Appl Environ Microbiol 2012; 78:8045-55. [PMID: 22961893 PMCID: PMC3485966 DOI: 10.1128/aem.02363-12] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2012] [Accepted: 09/03/2012] [Indexed: 11/20/2022] Open
Abstract
Experimental oral challenge studies with three different genotypes of Escherichia coli O157:H7 were conducted in cattle to determine the genotype-specific variability in shedding frequencies and concentrations and the frequency and extent of contamination of the environment. The results indicated that the E. coli O157:H7 genotype and ecological origin maybe important factors for the occurrence and concentration in the cattle host. Four groups of six young Holstein steers each were orally challenged with 10(6) CFU of one of three E. coli O157:H7 strains: FRIK 47 (groups 1 and 2), FRIK 1641 (group 3), and FRIK 2533 (group 4). Recto-anal mucosal swabs (RAMS) and environmental samples were taken on alternate days over 30 days. The numbers of E. coli O157:H7 cells and generic E. coli cells per sample were determined. Also, the presence and absence of 28 gene targets were determined for 2,411 isolates using high-throughput real-time PCR. Over the study period, strains FRIK 47, FRIK 1641, and FRIK 2533 were detected in 52%, 42%, and 2% of RAMS, respectively. Environmental detection of the challenge strains was found mainly in samples of the hides and pen floors, with strains FRIK 47, FRIK 1641, and FRIK 2533 detected in 22%, 27%, and 0% of environmental samples, respectively. Based on the panel of 28 gene targets, genotypes of enterohemorrhagic E. coli (EHEC) and generic E. coli from the experimental samples were clustered into three subgroups. In conclusion, the results suggested that the type and intensity of measures to control this pathogen at the preharvest level may need to be strain specific.
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Affiliation(s)
- Megan J. Kulow
- Department of Medical Sciences, School of Veterinary Medicine, University of Wisconsin, Madison, Wisconsin, USA
| | - Tina K. Gonzales
- Department of Medical Sciences, School of Veterinary Medicine, University of Wisconsin, Madison, Wisconsin, USA
| | - Kelly M. Pertzborn
- Department of Medical Sciences, School of Veterinary Medicine, University of Wisconsin, Madison, Wisconsin, USA
| | - James Dahm
- Department of Medical Sciences, School of Veterinary Medicine, University of Wisconsin, Madison, Wisconsin, USA
| | - Bret A. Miller
- Department of Medical Sciences, School of Veterinary Medicine, University of Wisconsin, Madison, Wisconsin, USA
| | - Dongjin Park
- Department of Bacteriology, University of Wisconsin, Madison, Wisconsin, USA
| | - Raju Gautam
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, USA
| | - Charles W. Kaspar
- Department of Bacteriology, University of Wisconsin, Madison, Wisconsin, USA
| | - Renata Ivanek
- Department of Veterinary Integrative Biosciences, College of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, Texas, USA
| | - Dörte Döpfer
- Department of Medical Sciences, School of Veterinary Medicine, University of Wisconsin, Madison, Wisconsin, USA
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46
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Vande Walle K, Vanrompay D, Cox E. Bovine innate and adaptive immune responses against Escherichia coli O157:H7 and vaccination strategies to reduce faecal shedding in ruminants. Vet Immunol Immunopathol 2012; 152:109-20. [PMID: 23084625 DOI: 10.1016/j.vetimm.2012.09.028] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Enterohaemorrhagic E. coli (EHEC) O157:H7 is a zoonotic pathogen of worldwide importance causing foodborne infections with possibly life-threatening consequences in humans, such as haemorrhagic colitis and in a small percentage of zoonotic cases, haemolytic-uremic syndrome (HUS). Ruminants are an important reservoir of EHEC and human infections are most frequently associated with direct or indirect contact with ruminant faeces. A thorough understanding of the host-bacterium interaction in ruminants could lead to the development of novel interventions strategies, including innovative vaccines. This review aims to present the current knowledge regarding innate and adaptive immune responses in EHEC colonized ruminants. In addition, results on vaccination strategies in ruminants aiming at reduction of EHEC shedding are reviewed.
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Affiliation(s)
- Kris Vande Walle
- Laboratory of Immunology, Faculty of Veterinary Medicine, Ghent University, Salisburylaan 133, 9860 Merelbeke, Belgium
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47
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Ennis C, McDowell D, Bolton DJ. The prevalence, distribution and characterization of Shiga toxin-producing Escherichia coli (STEC) serotypes and virulotypes from a cluster of bovine farms. J Appl Microbiol 2012; 113:1238-48. [PMID: 22862826 DOI: 10.1111/j.1365-2672.2012.05421.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2012] [Revised: 07/23/2012] [Accepted: 07/31/2012] [Indexed: 12/23/2022]
Abstract
AIMS To assess the prevalence of Shiga toxin-producing Escherichia coli (STEC) on a cluster of twelve beef farms in the north-east of Ireland. METHODS AND RESULTS Samples were screened for stx1 and stx2 using PCR. Positive samples were enriched in mTSB and STEC O157 isolated using immunomagnetic separation. Enrichment cultures were plated onto TBX agar to isolate non-O157 STEC. All isolates were serotyped and examined for a range of virulence genes and their antibiotic resistance phenotype determined. Eighty-four isolates of 33 different serotypes were cultured from the 13·7% of samples that were stx positive. The most prevalent serotype was O157:H7, the most common Shiga toxin was stx(2) , and a variety of virulence factor combinations was observed. O-:H-, O26:H11, O76:H34, O157:H7, O157:H16 and OX18:H+ also carried eaeA and hlyA genes. Twenty-nine per cent of strains were resistant to at least one antibiotic, 48% of which had multiple drug resistance (MDR) with O2:H32 displaying resistance to five antibiotics. CONCLUSIONS The ubiquitous nature of STEC on beef farms, the detection of stx(+) eaeA(+) hlyA(+) in the serotypes O-:H-, O157:H16 and OX18:H+ in addition to O157:H7 and O26:H11 and the widespread distribution of antibiotic resistance are of public health concern as new virulent STEC strains are emerging. SIGNIFICANCE AND IMPACT OF THE STUDY This study found no relationship between serotype and antibiotic resistance, therefore negating efforts to isolate serotypes using specific antibiotic supplemented media. The data presented provide further evidence of the emergence of new STEC virulotypes of potential public health significance.
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Affiliation(s)
- C Ennis
- Department of Food Safety, Teagasc Food Research Centre, Ashtown, Dublin, Ireland
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Fernandez-Brando RJ, Miliwebsky E, Mejías MP, Baschkier A, Panek CA, Abrey-Recalde MJ, Cabrera G, Ramos MV, Rivas M, Palermo MS. Shiga toxin-producing Escherichia coli O157 : H7 shows an increased pathogenicity in mice after the passage through the gastrointestinal tract of the same host. J Med Microbiol 2012; 61:852-859. [DOI: 10.1099/jmm.0.041251-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Romina J. Fernandez-Brando
- División Inmunología, Instituto de Medicina Experimental (CONICET), Academia Nacional de Medicina, Buenos Aires, Argentina
| | - Elizabeth Miliwebsky
- Servicio Fisiopatogenia, Instituto Nacional de Enfermedades Infecciosas – ANLIS ‘Dr Carlos G. Malbrán’, Buenos Aires, Argentina
| | - María Pilar Mejías
- División Inmunología, Instituto de Medicina Experimental (CONICET), Academia Nacional de Medicina, Buenos Aires, Argentina
| | - Ariela Baschkier
- Servicio Fisiopatogenia, Instituto Nacional de Enfermedades Infecciosas – ANLIS ‘Dr Carlos G. Malbrán’, Buenos Aires, Argentina
| | - Cecilia A. Panek
- División Inmunología, Instituto de Medicina Experimental (CONICET), Academia Nacional de Medicina, Buenos Aires, Argentina
| | - María Jimena Abrey-Recalde
- División Inmunología, Instituto de Medicina Experimental (CONICET), Academia Nacional de Medicina, Buenos Aires, Argentina
| | - Gabriel Cabrera
- División Inmunología, Instituto de Medicina Experimental (CONICET), Academia Nacional de Medicina, Buenos Aires, Argentina
| | - María Victoria Ramos
- División Inmunología, Instituto de Medicina Experimental (CONICET), Academia Nacional de Medicina, Buenos Aires, Argentina
| | - Marta Rivas
- Servicio Fisiopatogenia, Instituto Nacional de Enfermedades Infecciosas – ANLIS ‘Dr Carlos G. Malbrán’, Buenos Aires, Argentina
| | - Marina S. Palermo
- División Inmunología, Instituto de Medicina Experimental (CONICET), Academia Nacional de Medicina, Buenos Aires, Argentina
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Intraspecies variation in the emergence of hyperinfectious bacterial strains in nature. PLoS Pathog 2012; 8:e1002647. [PMID: 22511871 PMCID: PMC3325197 DOI: 10.1371/journal.ppat.1002647] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2010] [Accepted: 03/01/2012] [Indexed: 12/29/2022] Open
Abstract
Salmonella is a principal health concern because of its endemic prevalence in food and water supplies, the rise in incidence of multi-drug resistant strains, and the emergence of new strains associated with increased disease severity. Insights into pathogen emergence have come from animal-passage studies wherein virulence is often increased during infection. However, these studies did not address the prospect that a select subset of strains undergo a pronounced increase in virulence during the infective process- a prospect that has significant implications for human and animal health. Our findings indicate that the capacity to become hypervirulent (100-fold decreased LD50) was much more evident in certain S. enterica strains than others. Hyperinfectious salmonellae were among the most virulent of this species; restricted to certain serotypes; and more capable of killing vaccinated animals. Such strains exhibited rapid (and rapidly reversible) switching to a less-virulent state accompanied by more competitive growth ex vivo that may contribute to maintenance in nature. The hypervirulent phenotype was associated with increased microbial pathogenicity (colonization; cytotoxin production; cytocidal activity), coupled with an altered innate immune cytokine response within infected cells (IFN-β; IL-1β; IL-6; IL-10). Gene expression analysis revealed that hyperinfectious strains display altered transcription of genes within the PhoP/PhoQ, PhoR/PhoB and ArgR regulons, conferring changes in the expression of classical virulence functions (e.g., SPI-1; SPI-2 effectors) and those involved in cellular physiology/metabolism (nutrient/acid stress). As hyperinfectious strains pose a potential risk to human and animal health, efforts toward mitigation of these potential food-borne contaminants may avert negative public health impacts and industry-associated losses. Salmonellosis continues to compromise human health, animal welfare, and modern agriculture. Developing a comprehensive control plan requires an understanding of how pathogens emerge and express traits that confer increased incidence and severity of disease. It is well-established that animal passage often results in increased virulence; however, our findings indicate that the capacity to undergo a pronounced increase in virulence after passage was much more prevalent in certain Salmonella isolates than in others. The resultant hyperinfectious strains are among the most virulent salmonellae reported; were restricted to certain serotypes; and were able to override the immunity conferred in vaccinated animals. The induction of hypervirulence was responsive to subtle changes in environmental conditions and, potentially, may occur in other salmonellae serotypes after passage through certain hosts and/or exposure to certain environmental variables; a response that may be common across the microbial realm. Thus, management practices and environmental conditions inherent to livestock production have the potential to inadvertently trigger hypervirulence (e.g., diet; herd size; exposure to livestock waste and/or antimicrobials). From a farm management perspective, careful consideration must be given to risk-management strategies that reduce emergence/persistence of these potential food-borne contaminants to safeguard public health and reduce industry-associated losses.
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S. Bachoon D, M. Lukman M, D. Burt C. Detection of <i>Stx</i>2 Gene of <i>Escherichia coli</i> and Elevated Levels of Fecal Bacteria in the Cattle Farming Regions of Lake Oconee. ACTA ACUST UNITED AC 2012. [DOI: 10.4236/aim.2012.24067] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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