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Pokharel P, Dhakal S, Dozois CM. The Diversity of Escherichia coli Pathotypes and Vaccination Strategies against This Versatile Bacterial Pathogen. Microorganisms 2023; 11:344. [PMID: 36838308 PMCID: PMC9965155 DOI: 10.3390/microorganisms11020344] [Citation(s) in RCA: 22] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2023] [Revised: 01/24/2023] [Accepted: 01/25/2023] [Indexed: 02/03/2023] Open
Abstract
Escherichia coli (E. coli) is a gram-negative bacillus and resident of the normal intestinal microbiota. However, some E. coli strains can cause diseases in humans, other mammals and birds ranging from intestinal infections, for example, diarrhea and dysentery, to extraintestinal infections, such as urinary tract infections, respiratory tract infections, meningitis, and sepsis. In terms of morbidity and mortality, pathogenic E. coli has a great impact on public health, with an economic cost of several billion dollars annually worldwide. Antibiotics are not usually used as first-line treatment for diarrheal illness caused by E. coli and in the case of bloody diarrhea, antibiotics are avoided due to the increased risk of hemolytic uremic syndrome. On the other hand, extraintestinal infections are treated with various antibiotics depending on the site of infection and susceptibility testing. Several alarming papers concerning the rising antibiotic resistance rates in E. coli strains have been published. The silent pandemic of multidrug-resistant bacteria including pathogenic E. coli that have become more difficult to treat favored prophylactic approaches such as E. coli vaccines. This review provides an overview of the pathogenesis of different pathotypes of E. coli, the virulence factors involved and updates on the major aspects of vaccine development against different E. coli pathotypes.
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Affiliation(s)
- Pravil Pokharel
- Centre Armand-Frappier Santé Biotechnologie, Institut National de la Recherche Scientifique (INRS), 531 Boul des Prairies, Laval, QC H7V 1B7, Canada
- Centre de Recherche en Infectiologie Porcine et Avicole (CRIPA), Faculté de Médecine Vétérinaire, Université de Montréal Saint-Hyacinthe, Saint-Hyacinthe, QC J2S 2M2, Canada
| | - Sabin Dhakal
- Centre Armand-Frappier Santé Biotechnologie, Institut National de la Recherche Scientifique (INRS), 531 Boul des Prairies, Laval, QC H7V 1B7, Canada
- Centre de Recherche en Infectiologie Porcine et Avicole (CRIPA), Faculté de Médecine Vétérinaire, Université de Montréal Saint-Hyacinthe, Saint-Hyacinthe, QC J2S 2M2, Canada
| | - Charles M. Dozois
- Centre Armand-Frappier Santé Biotechnologie, Institut National de la Recherche Scientifique (INRS), 531 Boul des Prairies, Laval, QC H7V 1B7, Canada
- Centre de Recherche en Infectiologie Porcine et Avicole (CRIPA), Faculté de Médecine Vétérinaire, Université de Montréal Saint-Hyacinthe, Saint-Hyacinthe, QC J2S 2M2, Canada
- Pasteur Network, Laval, QC H7V 1B7, Canada
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Bao CL, Liu SZ, Shang ZD, Liu YJ, Wang J, Zhang WX, Dong B, Cao YH. Bacillus amyloliquefaciens TL106 protects mice against enterohaemorrhagic Escherichia coli O157:H7-induced intestinal disease through improving immune response, intestinal barrier function and gut microbiota. J Appl Microbiol 2020; 131:470-484. [PMID: 33289241 DOI: 10.1111/jam.14952] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2020] [Revised: 11/24/2020] [Accepted: 11/26/2020] [Indexed: 01/20/2023]
Abstract
AIMS This study evaluated the effects of Bacillus amyloliquefaciens TL106, isolated from Tibetan pigs' faeces, on the growth performance, immune response, intestinal barrier function, morphology of jejunum, caecum and colon, and gut microbiota in the mice with enterohaemorrhagic Escherichia coli (EHEC)-induced intestinal diseases. METHODS AND RESULTS In all, 40 female C57BL/6J mice were randomly divided into four groups: mice fed a normal diet (Control), mice oral administration of TL106 daily (Ba), mice challenged with EHEC O157:H7 on day 15 (O157) and mice oral administration of TL106 daily and challenged with EHEC O157:H7 on day 15 (Ba+O157). The TL106 was administrated to mice for 14 days, and mice were infected with O157:H7 at day 15. We found that TL106 could prevent the weight loss caused by O157:H7 infection and alleviated the associated increase in pro-inflammatory factors (TNF-α, IL-1β, IL-6 and IL-8) and decrease in anti-inflammatory factor (IL-10) in serum and intestinal tissues of mice caused by O157:H7 infection (P < 0·05). Additionally, TL106 could prevent disruption of gut morphology caused by O157:H7 infection, and alleviate the associated decrease in expression of tight junction proteins (ZO-1, occludin and claudin-1) in jejunum and colon (P < 0·05). In caecum and colon, the alpha diversity for bacterial community analysis of Chao and ACE index in Ba+O157 group were higher than O157 group. The TL106 stabilized gut microbiota disturbed by O157:H7, including increasing Lachnospiraceae, Prevotellaceae, Muribaculaceae and Akkermansiaceae, and reducing Lactobacillaceae. CONCLUSIONS We indicated the B. amyloliquefaciens TL106 can effectively protect mice against EHEC O157:H7 infection by relieving inflammation, improving intestinal barrier function, mitigating permeability disruption and stabilizing the gut microbiota. SIGNIFICANCE AND IMPACT OF THE STUDY Bacillus amyloliquefaciens TL106 can prevent and treat intestinal disease induced by EHEC O157:H7 in mice, which may be a promising probiotic for disease prevention in animals.
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Affiliation(s)
- C L Bao
- State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing, People's Republic of China
| | - S Z Liu
- College of Animal Science, Tibet Agricultural and Animal Husbandry University, Linzhi, People's Republic of China
| | - Z D Shang
- College of Animal Science, Tibet Agricultural and Animal Husbandry University, Linzhi, People's Republic of China
| | - Y J Liu
- State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing, People's Republic of China
| | - J Wang
- State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing, People's Republic of China
| | - W X Zhang
- State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing, People's Republic of China
| | - B Dong
- State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing, People's Republic of China
| | - Y H Cao
- State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing, People's Republic of China
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Sharma VK, Akavaram S, Schaut RG, Bayles DO. Comparative genomics reveals structural and functional features specific to the genome of a foodborne Escherichia coli O157:H7. BMC Genomics 2019; 20:196. [PMID: 30849935 PMCID: PMC6408774 DOI: 10.1186/s12864-019-5568-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Accepted: 02/25/2019] [Indexed: 01/09/2023] Open
Abstract
Background Escherichia coli O157:H7 (O157) has been linked to numerous foodborne disease outbreaks. The ability to rapidly sequence and analyze genomes is important for understanding epidemiology, virulence, survival, and evolution of outbreak strains. In the current study, we performed comparative genomics to determine structural and functional features of the genome of a foodborne O157 isolate NADC 6564 and infer its evolutionary relationship to other O157 strains. Results The chromosome of NADC 6564 contained 5466 kb compared to reference strains Sakai (5498 kb) and EDL933 (5547 kb) and shared 41 of its 43 Linear Conserved Blocks (LCB) with the reference strains. However, 18 of 41 LCB had inverse orientation in NADC 6564 compared to the reference strains. NADC 6564 shared 18 of 19 bacteriophages with reference strains except that the chromosomal positioning of some of the phages differed among these strains. The additional phage (P19) of NADC 6564 was located on a 39-kb insertion element (IE) encoding several hypothetical proteins, an integrase, transposases, transcriptional regulators, an adhesin, and a phosphoethanolamine transferase (PEA). The complete homologs of the 39-kb IE were found in E. coli PCN061 of porcine origin. The IE-encoded PEA showed low homology (32–33%) to four other PEA in NADC 6564 and PEA linked to mobilizable colistin resistance in E. coli but was highly homologous (95%) to a PEA of uropathogenic, avian pathogenic, and enteroaggregative E. coli. NADC 6564 showed slightly higher minimum inhibitory concentration of colistin compared to the reference strains. The 39-kb IE also contained dndBCDE and dptFGH operons encoding DNA S-modification and a restriction pathway, linked to oxidative stress tolerance and self-defense against foreign DNA, respectively. Evolutionary tree analysis grouped NADC 6564 with lineage I O157 strains. Conclusions These results indicated that differential phage counts and different chromosomal positioning of many bacteriophages and genomic islands might have resulted in recombination events causing altered chromosomal organization in NADC 6564. Evolutionary analysis grouped NADC 6564 with lineage I strains and suggested its earlier divergence from these strains. The ability to perform S-DNA modification might affect tolerance of NADC 6564 to various stressors. Electronic supplementary material The online version of this article (10.1186/s12864-019-5568-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Vijay K Sharma
- Food Safety and Enteric Pathogens Research Unit, USDA, ARS, National Animal Disease Center, 1920 Dayton Avenue, P.O. Box 70, Ames, IA, 50010, USA.
| | - Suryatej Akavaram
- Food Safety and Enteric Pathogens Research Unit, USDA, ARS, National Animal Disease Center, 1920 Dayton Avenue, P.O. Box 70, Ames, IA, 50010, USA
| | - Robert G Schaut
- Food Safety and Enteric Pathogens Research Unit, USDA, ARS, National Animal Disease Center, 1920 Dayton Avenue, P.O. Box 70, Ames, IA, 50010, USA.,Oak Ridge Institute for Science and Education (ORISE), ARS Research Participation Program, MS 36, P.O. Box 117, Oak Ridge, TN, 37831, USA
| | - Darrell O Bayles
- Infectious Bacterial Diseases Research Unit, National Animal Disease Center, ARS-USDA, Ames, Iowa, USA
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Bacterial Chat: Intestinal Metabolites and Signals in Host-Microbiota-Pathogen Interactions. Infect Immun 2017; 85:IAI.00476-17. [PMID: 28947641 DOI: 10.1128/iai.00476-17] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Intestinal bacteria employ microbial metabolites from the microbiota and chemical signaling during cell-to-cell communication to regulate several cellular functions. Pathogenic bacteria are extremely efficient in orchestrating their response to these signals through complex signaling transduction systems. Precise coordination and interpretation of these multiple chemical cues is important within the gastrointestinal (GI) tract. Enteric foodborne pathogens, such as enterohemorrhagic Escherichia coli (EHEC) and Salmonella enterica serovar Typhimurium, or the surrogate murine infection model for EHEC, Citrobacter rodentium, are all examples of microorganisms that modulate the expression of their virulence repertoire in response to signals from the microbiota or the host, such as autoinducer-3 (AI-3), epinephrine (Epi), and norepinephrine (NE). The QseBC and QseEF two-component systems, shared by these pathogens, are involved in sensing these signals. We review how these signaling systems sense and relay these signals to drive bacterial gene expression; specifically, to modulate virulence. We also review how bacteria chat via chemical signals integrated with metabolite recognition and utilization to promote successful associations among enteric pathogens, the microbiota, and the host.
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Abstract
Enteric pathogens such as enterohemorrhagic Escherichia coli (EHEC) and Citrobacter rodentium, which is largely used as a surrogate EHEC model for murine infections, are exposed to several host neurotransmitters in the gut. An important chemical exchange within the gut involves the neurotransmitters epinephrine and/or norepinephrine, extensively reported to increase virulence gene expression in EHEC, acting through two bacterial adrenergic sensors: QseC and QseE. However, EHEC is unable to establish itself and cause its hallmark lesions, attaching and effacing (AE) lesions, on murine enterocytes. To address the role of these neurotransmitters during enteric infection, we employed C. rodentium. Both EHEC and C. rodentium harbor the locus of enterocyte effacement (LEE) that is necessary for AE lesion formation. Here we show that expression of the LEE, as well as that of other virulence genes in C. rodentium, is also activated by epinephrine and/or norepinephrine. Both QseC and QseE are required for LEE gene activation in C. rodentium, and the qseC and qseE mutants are attenuated for murine infection. C. rodentium has a decreased ability to colonize dopamine β-hydroxylase knockout (Dbh−/−) mice, which do not produce epinephrine and norepinephrine. Both adrenergic sensors are required for C. rodentium to sense these neurotransmitters and activate the LEE genes during infection. These data indicate that epinephrine and norepinephrine are sensed by bacterial adrenergic receptors during enteric infection to promote activation of their virulence repertoire. This is the first report of the role of these neurotransmitters during mammalian gastrointestinal (GI) infection by a noninvasive pathogen. The epinephrine and norepinephrine neurotransmitters play important roles in gut physiology and motility. Of note, epinephrine and norepinephrine play a central role in stress responses in mammals, and stress has profound effects on GI function. Bacterial enteric pathogens exploit these neurotransmitters as signals to coordinate the regulation of their virulence genes. The bacterial QseC and QseE adrenergic sensors are at the center of this regulatory cascade. C. rodentium is a noninvasive murine pathogen with a colonization mechanism similar to that of EHEC, enabling the investigation of host signals in mice. The presence of these neurotransmitters in the gut is necessary for C. rodentium to fully activate its virulence program, in a QseC/QseE-dependent manner, to successfully colonize its murine host. Our study data provide the first example of epinephrine and norepinephrine signaling within the gut to stimulate infection by a bacterial pathogen in a natural animal infection.
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Abstract
The first major outbreaks caused by enterohemorrhagic Escherichia coli (EHEC) raised public and medical awareness of the risks associated with acquiring this potentially deadly infection. The widespread presence of these organisms in the environment, the severity of the clinical sequelae, and the lack of treatment options and effective preventive measures demand that we obtain a better understanding of how this group of organisms cause disease. Animal models allow study of the processes and factors that contribute to disease and, as such, form a valuable tool in the repertoire of infectious disease researchers. Yet despite more than 30 years of research, it seems that no single model host reproduces the full spectrum of clinical disease induced by EHEC in humans. In the first part of this review, a synopsis of what is known about EHEC infections is garnered from human outbreaks and biopsy specimens. The main features and limitations of EHEC infection models that are based on the three most commonly used species (pigs, rabbits, and mice) are described within a historical context. Recent advances are highlighted, and a brief overview of models based on other species is given. Finally, the impact of the host on moderating EHEC infection is considered in light of growing evidence for the need to consider the biology and virulence strategies of EHEC in the context of its niche within the intestine.
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Abstract
Shiga toxin (Stx) is the primary cause of severe host responses including renal and central nervous system (CNS) disease in Shiga toxin-producing E. coli (STEC) infections. The interaction of Stx with different eukaryotic cell types is described. Host responses to Stx and bacterial lipopolysaccharide (LPS) are compared as related to the features of the STEC-associated Hemolytic Uremic Syndrome (HUS). Data derived from animal models of HUS and CNS disease, in vivo, and eukaryotic cells, in vitro, are evaluated in relation to HUS disease of humans.
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Tironi-Farinati C, Geoghegan PA, Cangelosi A, Pinto A, Loidl CF, Goldstein J. A translational murine model of sub-lethal intoxication with Shiga toxin 2 reveals novel ultrastructural findings in the brain striatum. PLoS One 2013; 8:e55812. [PMID: 23383285 PMCID: PMC3561315 DOI: 10.1371/journal.pone.0055812] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2012] [Accepted: 01/04/2013] [Indexed: 12/27/2022] Open
Abstract
Infection by Shiga toxin-producing Escherichia coli causes hemorrhagic colitis, hemolytic uremic syndrome (HUS), acute renal failure, and also central nervous system complications in around 30% of the children affected. Besides, neurological deficits are one of the most unrepairable and untreatable outcomes of HUS. Study of the striatum is relevant because basal ganglia are one of the brain areas most commonly affected in patients that have suffered from HUS and since the deleterious effects of a sub-lethal dose of Shiga toxin have never been studied in the striatum, the purpose of this study was to attempt to simulate an infection by Shiga toxin-producing E. coli in a murine model. To this end, intravenous administration of a sub-lethal dose of Shiga toxin 2 (0.5 ηg per mouse) was used and the correlation between neurological manifestations and ultrastructural changes in striatal brain cells was studied in detail. Neurological manifestations included significant motor behavior abnormalities in spontaneous motor activity, gait, pelvic elevation and hind limb activity eight days after administration of the toxin. Transmission electron microscopy revealed that the toxin caused early perivascular edema two days after administration, as well as significant damage in astrocytes four days after administration and significant damage in neurons and oligodendrocytes eight days after administration. Interrupted synapses and mast cell extravasation were also found eight days after administration of the toxin. We thus conclude that the chronological order of events observed in the striatum could explain the neurological disorders found eight days after administration of the toxin.
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Affiliation(s)
- Carla Tironi-Farinati
- Laboratorio de Neurofisiopatología, Departamento de Fisiología, Facultad de Medicina, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina
| | - Patricia A. Geoghegan
- Centro Nacional de Control de Calidad de Biológicos (CNCCB) – ANLIS “Dr. Carlos G. Malbrán”, Ciudad Autónoma de Buenos Aires, Argentina
| | - Adriana Cangelosi
- Centro Nacional de Control de Calidad de Biológicos (CNCCB) – ANLIS “Dr. Carlos G. Malbrán”, Ciudad Autónoma de Buenos Aires, Argentina
| | - Alipio Pinto
- Laboratorio de Neurofisiopatología, Departamento de Fisiología, Facultad de Medicina, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina
| | - C. Fabian Loidl
- Instituto de Biología Celular y Neurociencia “Prof. E. De Robertis”, Facultad de Medicina, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina
| | - Jorge Goldstein
- Laboratorio de Neurofisiopatología, Departamento de Fisiología, Facultad de Medicina, Universidad de Buenos Aires, Ciudad Autónoma de Buenos Aires, Argentina
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Torres AG, Cieza RJ, Rojas-Lopez M, Blumentritt CA, Souza CS, Johnston RK, Strockbine N, Kaper JB, Sbrana E, Popov VL. In vivo bioluminescence imaging of Escherichia coli O104:H4 and role of aerobactin during colonization of a mouse model of infection. BMC Microbiol 2012; 12:112. [PMID: 22716772 PMCID: PMC3438087 DOI: 10.1186/1471-2180-12-112] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2012] [Accepted: 06/06/2012] [Indexed: 12/21/2022] Open
Abstract
Background A major outbreak of bloody diarrhea associated with Shiga toxin-producing Escherichia coli O104:H4 occurred early in 2011, to which an unusual number of hemolytic uremic syndrome cases were linked. Due to limited information regarding pathogenesis and/or virulence properties of this particular serotype, we investigated the contribution of the aerobactin iron transport system during in vitro and in vivo conditions. Results A bioluminescent reporter construct was used to perform real-time monitoring of E. coli O104:H4 in a mouse model of infection. We verified that our reporter strain maintained characteristics and growth kinetics that were similar to those of the wild-type E. coli strain. We found that the intestinal cecum of ICR (CD-1) mice was colonized by O104:H4, with bacteria persisting for up to 7 days after intragastric inoculation. MALDI-TOF analysis of heat-extracted proteins was performed to identify putative surface-exposed virulence determinants. A protein with a high similarity to the aerobactin iron receptor was identified and further demonstrated to be up-regulated in E. coli O104:H4 when grown on MacConkey agar or during iron-depleted conditions. Because the aerobactin iron acquisition system is a key virulence factor in Enterobacteriaceae, an isogenic aerobactin receptor (iutA) mutant was created and its intestinal fitness assessed in the murine model. We demonstrated that the aerobactin mutant was out-competed by the wild-type E. coli O104:H4 during in vivo competition experiments, and the mutant was unable to persist in the cecum. Conclusion Our findings demonstrate that bioluminescent imaging is a useful tool to monitor E. coli O104:H4 colonization properties, and the murine model can become a rapid way to evaluate bacterial factors associated with fitness and/or colonization during E. coli O104:H4 infections.
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Affiliation(s)
- Alfredo G Torres
- Department of Microbiology and Immunology, University of Texas Medical Branch, Galveston, TX 77555-1070, USA.
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Magnus T, Röther J, Simova O, Meier-Cillien M, Repenthin J, Möller F, Gbadamosi J, Panzer U, Wengenroth M, Hagel C, Kluge S, Stahl RK, Wegscheider K, Urban P, Eckert B, Glatzel M, Fiehler J, Gerloff C. The neurological syndrome in adults during the 2011 northern German E. coli serotype O104:H4 outbreak. Brain 2012; 135:1850-9. [DOI: 10.1093/brain/aws090] [Citation(s) in RCA: 88] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Differential virulence of clinical and bovine-biased enterohemorrhagic Escherichia coli O157:H7 genotypes in piglet and Dutch belted rabbit models. Infect Immun 2011; 80:369-80. [PMID: 22025512 DOI: 10.1128/iai.05470-11] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Enterohemorrhagic Escherichia coli O157:H7 (EHEC O157) is an important cause of food and waterborne illness in the developed countries. Cattle are a reservoir host of EHEC O157 and a major source of human exposure through contaminated meat products. Shiga toxins (Stxs) are an important pathogenicity trait of EHEC O157. The insertion sites of the Stx-encoding bacteriophages differentiate EHEC O157 isolates into genogroups commonly isolated from cattle but rarely from sick humans (bovine-biased genotypes [BBG]) and those commonly isolated from both cattle and human patients (clinical genotypes [CG]). Since BBG and CG share the cardinal virulence factors of EHEC O157 and are carried by cattle at similar prevalences, the infrequent occurrence of BBG among human disease isolates suggests that they may be less virulent than CG. We compared the virulence potentials of human and bovine isolates of CG and BBG in newborn conventional pig and weaned Dutch Belted rabbit models. CG-challenged piglets experienced severe disease accompanied by early and high mortality compared to BBG-challenged piglets. Similarly, CG-challenged rabbits were likely to develop lesions in kidney and intestine compared with the BBG-challenged rabbits. The CG strains used in this study carried stx2 and produced significantly higher amounts of Stx, whereas the BBG strains carried the stx2c gene variant only. These results suggest that BBG are less virulent than CG and that this difference in virulence potential is associated with the Stx2 subtype(s) carried and/or the amount of Stx produced.
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Abstract
Shiga toxin-producing Escherichia coli is a contaminant of food and water that in humans causes a diarrheal prodrome followed by more severe disease of the kidneys and an array of symptoms of the central nervous system. The systemic disease is a complex referred to as diarrhea-associated hemolytic uremic syndrome (D+HUS). D+HUS is characterized by thrombocytopenia, microangiopathic hemolytic anemia, and acute renal failure. This review focuses on the renal aspects of D+HUS. Current knowledge of this renal disease is derived from a combination of human samples, animal models of D+HUS, and interaction of Shiga toxin with isolated renal cell types. Shiga toxin is a multi-subunit protein complex that binds to a glycosphingolipid receptor, Gb3, on select eukaryotic cell types. Location of Gb3 in the kidney is predictive of the sites of action of Shiga toxin. However, the toxin is cytotoxic to some, but not all cell types that express Gb3. It also can cause apoptosis or generate an inflammatory response in some cells. Together, this myriad of results is responsible for D+HUS disease.
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Affiliation(s)
- Tom G Obrig
- Department of Microbiology and Immunology, School of Medicine, University of Maryland, 685 W. Baltimore St., HSF I Suite 380, Baltimore, MD 21201, USA; ; Tel.: +1-410-706-6917
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Obata F. Influence of Escherichia coli Shiga Toxin on the Mammalian Central Nervous System. ADVANCES IN APPLIED MICROBIOLOGY 2010; 71:1-19. [DOI: 10.1016/s0065-2164(10)71001-7] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Jacob ME, Fox JT, Reinstein SL, Nagaraja TG. Antimicrobial susceptibility of foodborne pathogens in organic or natural production systems: an overview. Foodborne Pathog Dis 2009; 5:721-30. [PMID: 18847380 DOI: 10.1089/fpd.2008.0095] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Organic and natural food production systems are increasing in popularity, at least partially because consumers perceive that these niche markets provide healthier and safer food products. One major difference between these niche markets and conventional production systems is the use of antimicrobials. Because antimicrobial agents exert selective pressures for antimicrobial resistance, relating antimicrobial susceptibility of foodborne bacteria to niche market production systems is of interest. Other differences between production systems might also influence the susceptibility of foodborne pathogens. The objective of this review is to compare the impact of food animal production systems on the antimicrobial susceptibility of common foodborne bacterial pathogens. Studies comparing the susceptibility of such pathogens were diverse in terms of geographic location, procedures, species of bacteria, and antimicrobials evaluated; thus, it was difficult to draw conclusions. The literature is highly variable in terms of production type and practices and susceptibility associations, although few studies have compared truly organic and conventional practices. When statistical associations were found between production type and minimum inhibitory concentrations or percentage of isolates resistant for a particular pathogen, the isolates from conventionally reared animals/products were more commonly resistant than the comparison group (organic, antibiotic free, etc.). Therefore, further studies are needed to better assess public health consequences of antimicrobial resistance and food animal production systems, specifically organic or natural versus conventional.
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Affiliation(s)
- Megan E Jacob
- Department of Diagnostic Medicine and Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, Kansas 66503-8663, USA
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Wells TJ, Sherlock O, Rivas L, Mahajan A, Beatson SA, Torpdahl M, Webb RI, Allsopp LP, Gobius KS, Gally DL, Schembri MA. EhaA is a novel autotransporter protein of enterohemorrhagic Escherichia coli O157:H7 that contributes to adhesion and biofilm formation. Environ Microbiol 2008; 10:589-604. [PMID: 18237301 DOI: 10.1111/j.1462-2920.2007.01479.x] [Citation(s) in RCA: 104] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Autotransporter (AT) proteins have been identified in many Gram-negative pathogens and are unique in that their primary sequence is sufficient to direct their transport across the bacterial membrane system. Where characterized they are uniformly associated with virulence. Using conserved AT motifs as a search tool, four putative AT proteins were identified in the Enterohemorrhagic Escherichia coli O157:H7 EDL933 genome. The genes encoding these proteins (z0402/ehaA, z0469/ehaB, z3487/ehaC and z3948/ehaD) were PCR amplified, cloned and expressed in an E. coli K-12 MG1655flu background. Preliminary characterization revealed that ehaA, ehaB and ehaD encode proteins associated with increased biofilm formation. One of these genes (ehaA) resides on a genomic island in E. coli O157:H7 strains EDL933 and Sakai. Over-expression of EhaA in E. coli K-12 demonstrated it is located at the cell surface and resulted in the formation of large cell aggregates, promoted significant biofilm formation and mediated adhesion to primary epithelial cells of the bovine terminal rectum. The expression of ehaA was demonstrated in E. coli EDL933 by RT-PCR. An EhaA-specific antibody revealed the EhaA protein was expressed in 24/50 generic Shiga toxin-producing E. coli (STEC) strains of various serotypes including O157:H7. However, the deletion of ehaA from E. coli EDL933 and a STEC strain from serotype O111:H(-) did not affect biofilm growth. Our results suggest that EhaA may contribute to adhesion, colonization and biofilm formation by E. coli O157:H7 and possibly other STEC serotypes.
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Affiliation(s)
- Timothy J Wells
- School of Molecular and Microbial Sciences, University of Queensland, Brisbane, Queensland 4072, Australia
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Low AS, Holden N, Rosser T, Roe AJ, Constantinidou C, Hobman JL, Smith DGE, Low JC, Gally DL. Analysis of fimbrial gene clusters and their expression in enterohaemorrhagic Escherichia coli O157:H7. Environ Microbiol 2006; 8:1033-47. [PMID: 16689724 DOI: 10.1111/j.1462-2920.2006.00995.x] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The sequence of two enterohaemorrhagic Escherichia coli (EHEC) O157:H7 strains reveals the possession of at least 16 fimbrial gene clusters, many of the chaperone/usher class. The first part of this study examined the distribution of these clusters in a selection of EHEC/EPEC (enteropathogenic E. coli) serotypes to determine if any were likely to be unique to E. coli O157:H7. Six of the clusters, as determined by the presence of amplified main subunit or usher gene sequences, were detected only in the E. coli O157 and O145 serotypes tested. With the exception of one serotype O103 strain that contained an lpf2 cluster, lpf sequences were only detected in E. coli O157 of the serotypes tested. Expression from each cluster was measured by the construction of chromosomally integrated lacZ promoter fusions and plasmid-based eGFP fusions in E. coli O157:H7. This analysis demonstrated that the majority (11/15) of main fimbrial subunit genes were not expressed under the majority of conditions tested in vitro. One of the clusters showing promoter activity, loc8, has a temperature expression optimum indicating a possible role outside the host. From the presence of pseudogenes in three of the clusters, the lack of FimH-like minor adhesins in the clusters and their limited expression in vitro, it would appear that E. coli O157:H7 has a limited repertoire of expressed functional fimbriae. This restricted selection of fimbriae may be important in bringing about the tropism E. coli O157:H7 demonstrates for the terminal rectum of cattle.
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Affiliation(s)
- Alison S Low
- Zoonotic and Animal Pathogens Research Laboratory, Centre for Infectious Diseases, Chancellor's Building, University of Edinburgh, Edinburgh, EH16 4SB, UK
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17
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Naylor SW, Roe AJ, Nart P, Spears K, Smith DGE, Low JC, Gally DL. Escherichia coli O157 : H7 forms attaching and effacing lesions at the terminal rectum of cattle and colonization requires the LEE4 operon. MICROBIOLOGY-SGM 2005; 151:2773-2781. [PMID: 16079353 DOI: 10.1099/mic.0.28060-0] [Citation(s) in RCA: 122] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Enterohaemorrhagic Escherichia coli O157 : H7 is a human pathogen that causes no apparent disease in cattle, its primary reservoir host. Recent research has demonstrated that E. coli O157 : H7 predominately colonizes the distal few centimetres of the bovine rectum, and in this study, the LEE4 operon encoding a type III secretion system translocon and associated proteins was shown to be essential for colonization. A deletion mutant of LEE4 failed to colonize cattle, in contrast to a co-inoculated strain containing a chromosomal complement of the operon, therefore fulfilling 'molecular' Koch's postulates for this virulence determinant. In addition, attaching and effacing (A/E) lesions were detectable in E. coli O157 : H7 microcolonies from the terminal rectum of both naturally and experimentally colonized cattle when examined by transmission electron microscopy. This study proves that type III secretion is required for colonization of cattle by E. coli O157 : H7, and that A/E lesion formation occurs at the bovine terminal rectum within E. coli O157 : H7 microcolonies. The research confirms the value of using type III secreted proteins as vaccine candidates in cattle.
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Affiliation(s)
- Stuart W Naylor
- Animal Health Group, Scottish Agricultural College, West Mains Road, Edinburgh EH9 3JG, UK
| | - Andrew J Roe
- Zoonotic and Animal Pathogens Research Laboratory, Division of Veterinary Biomedical Sciences, Teviot Place, Edinburgh University, Edinburgh EH8 9AG, UK
| | - Pablo Nart
- Zoonotic and Animal Pathogens Research Laboratory, Division of Veterinary Biomedical Sciences, Teviot Place, Edinburgh University, Edinburgh EH8 9AG, UK
- Animal Health Group, Scottish Agricultural College, West Mains Road, Edinburgh EH9 3JG, UK
| | - Kevin Spears
- Zoonotic and Animal Pathogens Research Laboratory, Division of Veterinary Biomedical Sciences, Teviot Place, Edinburgh University, Edinburgh EH8 9AG, UK
| | - David G E Smith
- Functional Genomics Unit, Moredun Research Institute, Pentland Science Park, Mid Lothian EH26 0PZ, UK
| | - J Christopher Low
- Animal Health Group, Scottish Agricultural College, West Mains Road, Edinburgh EH9 3JG, UK
| | - David L Gally
- Zoonotic and Animal Pathogens Research Laboratory, Division of Veterinary Biomedical Sciences, Teviot Place, Edinburgh University, Edinburgh EH8 9AG, UK
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18
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Abstract
The emergence of enterohaemorrhagic Escherichia coli (EHEC) as major human pathogens began with the identification of serotype O157:H7 in the early 1980s as the cause of various food-borne outbreaks of severe intestinal disease. The key virulence factors include verocytotoxins (Vt) and effectors and adhesins associated with type III secretion systems. Tracing the origins of human outbreaks reveals that the primary source of this organism is the ruminant gastro-intestinal tract and a variety of transmission routes to humans have been identified. The epidemiology of E. coli O157:H7 within cattle and other ruminants has been studied extensively and the prevalence of non-O157:H7 serotypes contrasts with the observed dominance of E. coli O157:H7 amongst human EHEC isolates. Although there is some evidence that EHEC cause disease in young animals, the high prevalence of Vt within healthy ruminants suggests that this is not a virulence factor within these species. An understanding of the mechanisms underpinning EHEC persistence within their natural reservoir hosts and the development of a molecular understanding of EHEC biology and evolution could eventually allow a reduction in the incidence of human disease and may reduce future threats. The use of animal models to replicate and study human EHEC pathogenesis is described.
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Affiliation(s)
- Stuart W Naylor
- Animal Health Group, Scottish Agricultural College, West Mains Road, Edinburgh, EH9 3JG, UK.
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19
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Girard F, Oswald IP, Taranu I, Hélie P, Appleyard GD, Harel J, Fairbrother JM. Host immune status influences the development of attaching and effacing lesions in weaned pigs. Infect Immun 2005; 73:5514-23. [PMID: 16113267 PMCID: PMC1231136 DOI: 10.1128/iai.73.9.5514-5523.2005] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Attaching and effacing Escherichia coli (AEEC) has been associated with naturally occurring attaching and effacing (A/E) lesions in weaned pigs, and although A/E lesions have been experimentally reproduced in newborn piglets, such lesions have been much more difficult to induce in older conventional pigs. Hence, the aim of this study was to examine the effect of oral administration of dexamethasone on the development of A/E lesions in weaned pigs challenged with a porcine enteropathogenic E. coli (PEPEC) strain and to investigate the involvement of local intestinal cytokine response. Dexamethasone, given orally at a dosage of 3 mg kg of body weight(-1), significantly enhanced both the colonization of the challenge strain and the prevalence of foci of intimately adherent bacteria, resulting in extensive A/E lesions in the ileum, cecum, and colon of challenged pigs. We also confirmed the expression of both intimin and Tir by PEPEC strain ECL1001 in A/E lesions in vivo, which is, to our knowledge, the first report of the involvement of the latter proteins in any AEEC infections in vivo. Moreover, semiquantitative reverse transcription-PCR demonstrated that interleukin 1beta (IL-1beta), IL-6, IL-8, and, to a lesser extent, IL-12p40 are significantly upregulated in the ileum following challenge with strain ECL1001, whereas dexamethasone blocks such upregulation. Taken together, our results strongly suggested that host immune status influences the development of A/E lesions in weaned pigs, and it appears that IL-1beta, IL-6, IL-8, and, to a lesser extent, IL-12p40 are expressed during infection of weaned pigs by PEPEC and may contribute to the natural resistance of the host against PEPEC infection.
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Affiliation(s)
- Francis Girard
- Groupe de recherche sur les maladies infectieuses du porc, Faculté de médecine vétérinaire, Université de Montréal, Québec, Canada
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20
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Pohlenz JF, Winter KR, Dean-Nystrom EA. Shiga-toxigenic Escherichia coli-inoculated neonatal piglets develop kidney lesions that are comparable to those in humans with hemolytic-uremic syndrome. Infect Immun 2005; 73:612-6. [PMID: 15618202 PMCID: PMC538958 DOI: 10.1128/iai.73.1.612-616.2005] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Kidney lesions similar to those in humans with hemolytic-uremic syndrome were observed histologically in 82 of 122 piglets inoculated intragastrically with Shiga-toxigenic Escherichia coli but not in 29 controls. The locations of lesions matched locations where Stx-2 binding and Gb3 (globotriasylceramide receptors for Stx) were identified immunohistochemically.
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Affiliation(s)
- J F Pohlenz
- National Animal Disease Center, USDA, ARS, P.O. Box 70, Ames, IA 50010-0070, USA
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21
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Winter KRK, Stoffregen WC, Dean-Nystrom EA. Shiga toxin binding to isolated porcine tissues and peripheral blood leukocytes. Infect Immun 2004; 72:6680-4. [PMID: 15501802 PMCID: PMC523021 DOI: 10.1128/iai.72.11.6680-6684.2004] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Shiga toxin (Stx) binding sites in porcine tissues and leukocytes were identified by the use of Stx overlay and anti-CD77/Gb3 immunoassays. Stx1 and Stx2 bound to similar tissue locations and leukocytes, although some differences were noted. Previously unreported Stx binding sites were identified in kidney tubules, intestinal lymphoid aggregates, sinusoidal liver cells, alveolar macrophages, and peripheral blood leukocytes.
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Affiliation(s)
- Kellie R K Winter
- Department of Veterinary Microbiology and Preventive Medicine, Iowa State University, USDA Agricultural Research Service, National Animal Disease Center, Ames 50010-0070, USA
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22
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Cornick NA, Helgerson AF. Transmission and infectious dose of Escherichia coli O157:H7 in swine. Appl Environ Microbiol 2004; 70:5331-5. [PMID: 15345417 PMCID: PMC520915 DOI: 10.1128/aem.70.9.5331-5335.2004] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
Escherichia coli O157:H7 is only occasionally isolated from healthy swine, but some experimentally infected animals will shed the organism in their feces for at least 2 months. Potential explanations for the paucity of naturally occurring infections in swine, as compared to cattle, include a lack of animal-to-animal transmission so that the organism cannot be maintained within a herd, a high infectious dose, or herd management practices that prevent the maintenance of the organism in the gastrointestinal tract. We hypothesized that donor pigs infected with E. coli O157:H7 would transmit the organism to naïve pigs. We also determined the infectious dose and whether housing pigs individually on grated floors would decrease the magnitude or duration of fecal shedding. Infected donor pigs shedding <10(4) CFU of E. coli O157:H7 per g transmitted the organism to 6 of 12 naïve pigs exposed to them. The infectious dose of E. coli O157:H7 for 3-month-old pigs was approximately 6 x 10(3) CFU. There was no difference in the magnitude and duration of fecal shedding by pigs housed individually on grates compared to those housed two per pen on cement floors. These results suggest that swine do not have an innate resistance to colonization by E. coli O157:H7 and that they could serve as a reservoir host under suitable conditions.
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Affiliation(s)
- N A Cornick
- 2130 Veterinary Medicine Building, Iowa State University, Ames, IA 50011, USA.
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23
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Tzipori S, Sheoran A, Akiyoshi D, Donohue-Rolfe A, Trachtman H. Antibody therapy in the management of shiga toxin-induced hemolytic uremic syndrome. Clin Microbiol Rev 2004; 17:926-41, table of contents. [PMID: 15489355 PMCID: PMC523565 DOI: 10.1128/cmr.17.4.926-941.2004] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Hemolytic uremic syndrome (HUS) is a disease that can lead to acute renal failure and often to other serious sequelae, including death. The majority of cases are attributed to infections with Escherichia coli, serotype O157:H7 strains in particular, which cause bloody diarrhea and liberate one or two toxins known as Shiga toxins 1 and 2. These toxins are thought to directly be responsible for the manifestations of HUS. Currently, supportive nonspecific treatment is the only available option for the management of individuals presenting with HUS. The benefit of antimicrobial therapy remains uncertain because of several reports which claim that such intervention can in fact exacerbate the syndrome. There have been only a few specific therapies directed against neutralizing the activities of these toxins, but none so far has been shown to be effective. This article reviews the literature on the mechanism of action of these toxins and the clinical manifestations and current management and treatment of HUS. The major focus of the article, however, is the development and rationale for using neutralizing human antibodies to combat this toxin-induced disease. Several groups are currently pursuing this approach with either humanized, chimeric, or human antitoxin antibodies produced in transgenic mice. They are at different phases of development, ranging from preclinical evaluation to human clinical trials. The information available from preclinical studies indicates that neutralizing specific antibodies directed against the A subunit of the toxin can be highly protective. Such antibodies, even when administered well after exposure to bacterial infection and onset of diarrhea, can prevent the occurrence of systemic complications.
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Affiliation(s)
- Saul Tzipori
- Division of Infectious Diseases, Tufts University School of Veterinary Medicine, 200 Westborough Rd., North Grafton, MA 01536, USA.
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24
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Dean-Nystrom EA, Melton-Celsa AR, Pohlenz JFL, Moon HW, O'Brien AD. Comparative pathogenicity of Escherichia coli O157 and intimin-negative non-O157 Shiga toxin-producing E coli strains in neonatal pigs. Infect Immun 2003; 71:6526-33. [PMID: 14573674 PMCID: PMC219560 DOI: 10.1128/iai.71.11.6526-6533.2003] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
We compared the pathogenicity of intimin-negative non-O157:H7 Shiga toxin (Stx)-producing Escherichia coli (STEC) O91:H21 and O104:H21 strains with the pathogenicity of intimin-positive O157:H7 and O157:H(-) strains in neonatal pigs. We also examined the role of Stx2d-activatable genes and the large hemolysin-encoding plasmid of O91:H21 strain B2F1 in the pathogenesis of STEC disease in pigs. We found that all E. coli strains that made wild-type levels of Stx caused systemic illness and histological lesions in the brain and intestinal crypts, whereas none of the control Stx-negative E. coli strains evoked comparable central nervous system signs or intestinal lesions. By contrast, the absence of intimin, hemolysin, or motility had little impact on the overall pathogenesis of systemic disease during STEC infection. The most striking differences between pigs inoculated with non-O157 STEC strains and pigs inoculated with O157 STEC strains were the absence of attaching and effacing intestinal lesions in pigs inoculated with non-O157:H7 strains and the apparent association between the level of Stx2d-activatable toxin produced by an STEC strain and the severity of lesions.
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Affiliation(s)
- Evelyn A Dean-Nystrom
- Pre-Harvest Food Safety and Enteric Research Unit, National Animal Disease Center, USDA Agricultural Research Service, Ames, Iowa 50010-0070, USA.
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25
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Gunzer F, Hennig-Pauka I, Waldmann KH, Sandhoff R, Gröne HJ, Kreipe HH, Matussek A, Mengel M. Gnotobiotic piglets develop thrombotic microangiopathy after oral infection with enterohemorrhagic Escherichia coli. Am J Clin Pathol 2002; 118:364-75. [PMID: 12219778 DOI: 10.1309/umw9-d06q-m94q-jgh2] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
Oral infection with enterohemorrhagic Escherichia coli (EHEC) may cause severe enteritis, followed in up to 10% of cases by an extraintestinal complication, the hemolytic uremic syndrome (HUS). HUS is characterized by a triad of symptoms: anemia, thrombocytopenia, and acute renalfailure due to thrombotic microangiopathy. EHEC produces several virulence factors, among which a family of phage-encoded cytotoxins, called Shiga toxin 1 and Shiga toxin 2, seems to be most important. However, since an appropriate animal model is not available, pathogenicity of these emerging enteric pathogens is still poorly understood. Germ-free gnotobiotic piglets infected orally with an O1577:H7 or an O26:H11 EHEC wild-type isolate, both producing Shiga toxin 2, developed intestinal and extraintestinal manifestations of EHEC disease, including thrombotic microangiopathy in the kidneys, the morphologic hallmark of HUS in humans. Thus, gnotobiotic piglets are suitable to further study the pathophysiology of EHEC-induced HUS. It can be expected that data obtainedfrom this animal model will improve our current standard of knowledge about this emerging infectious disease.
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Affiliation(s)
- Florian Gunzer
- Institute of Medical Microbiology, Hannover Medical School, Germany
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26
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Cornick NA, Booher SL, Moon HW. Intimin facilitates colonization by Escherichia coli O157:H7 in adult ruminants. Infect Immun 2002; 70:2704-7. [PMID: 11953416 PMCID: PMC127945 DOI: 10.1128/iai.70.5.2704-2707.2002] [Citation(s) in RCA: 99] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We compared the magnitude and duration of fecal shedding of wild-type Escherichia coli O157:H7 to that of an isogenic intimin mutant in young adult cattle and sheep. In both ruminant species, wild-type E. coli O157:H7 was shed in greater numbers and for a longer duration than was the intimin mutant.
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Affiliation(s)
- Nancy A Cornick
- Department of Veterinary Microbiology and Preventative Medicine, College of Veterinary Medicine, Iowa State University, Ames, Iowa 50011, USA.
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27
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Dean-Nystrom EA, Gansheroff LJ, Mills M, Moon HW, O'Brien AD. Vaccination of pregnant dams with intimin(O157) protects suckling piglets from Escherichia coli O157:H7 infection. Infect Immun 2002; 70:2414-8. [PMID: 11953378 PMCID: PMC127944 DOI: 10.1128/iai.70.5.2414-2418.2002] [Citation(s) in RCA: 99] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Cattle are important reservoirs of enterohemorrhagic Escherichia coli (EHEC) O157:H7 that cause disease in humans. Both dairy and beef cattle are asymptomatically and sporadically infected with EHEC. Our long-term goal is to develop an effective vaccine to prevent cattle from becoming infected and transmitting EHEC O157:H7 to humans. We used passive immunization of neonatal piglets (as a surrogate model) to determine if antibodies against EHEC O157 adhesin (intimin(O157)) inhibit EHEC colonization. Pregnant swine (dams) with serum anti-intimin titers of < or =100 were vaccinated twice with purified intimin(O157) or sham-vaccinated with sterile buffer. Intimin(O157)-specific antibody titers in colostrum and serum of dams were increased after parenteral vaccination with intimin(O157). Neonatal piglets were allowed to suckle vaccinated or sham-vaccinated dams for up to 8 h before they were inoculated with 10(6) CFU of a Shiga toxin-negative (for humane reasons) strain of EHEC O157:H7. Piglets were necropsied at 2 to 10 days after inoculation, and intestinal samples were collected for determination of bacteriological counts and histopathological analysis. Piglets that ingested colostrum containing intimin(O157)-specific antibodies from vaccinated dams, but not those nursing sham-vaccinated dams, were protected from EHEC O157:H7 colonization and intestinal damage. These results establish intimin(O157) as a viable candidate for an EHEC O157:H7 antitransmission vaccine.
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Affiliation(s)
- Evelyn A Dean-Nystrom
- Pre-Harvest Food Safety and Enteric Diseases Research Unit, National Animal Disease Center, U.S. Department of Agriculture, Agricultural Research Service, Ames, Iowa 50010, USA.
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Mukherjee J, Chios K, Fishwild D, Hudson D, O'Donnell S, Rich SM, Donohue-Rolfe A, Tzipori S. Human Stx2-specific monoclonal antibodies prevent systemic complications of Escherichia coli O157:H7 infection. Infect Immun 2002; 70:612-9. [PMID: 11796590 PMCID: PMC127659 DOI: 10.1128/iai.70.2.612-619.2002] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2001] [Revised: 08/07/2001] [Accepted: 11/12/2001] [Indexed: 11/20/2022] Open
Abstract
Hemolytic-uremic syndrome (HUS) is a serious complication predominantly associated with infection by enterohemorrhagic Escherichia coli (EHEC), such as E. coli O157:H7. EHEC can produce Shiga toxin 1 (Stx1) and/or Shiga toxin 2 (Stx2), both of which are exotoxins comprised of active (A) and binding (B) subunits. In piglets and mice, Stx can induce fatal neurological symptoms. Polyclonal Stx2 antiserum can prevent these effects in piglets infected with the Stx2-producing E. coli O157:H7 strain 86-24. Human monoclonal antibodies (HuMAbs) against Stx2 were developed as potential passive immunotherapeutic reagents for the prevention and/or treatment of HUS. Transgenic mice bearing unrearranged human immunoglobulin (Ig) heavy and kappa light chain loci (HuMAb___Mouse) were immunized with formalin-inactivated Stx2. Thirty-seven stable hybridomas secreting Stx2-specific HuMAbs were isolated: 33 IgG1kappa A-subunit-specific and 3 IgG1kappa and 1 IgG3kappa B-subunit-specific antibodies. Six IgG1kappa A-subunit-specific (1G3, 2F10, 3E9, 4H9, 5A4, and 5C12) and two IgG1kappa B-subunit-specific (5H8 and 6G3) HuMAbs demonstrated neutralization of > 95% activity of 1 ng of Stx2 in the presence of 0.04 microg of HuMAb in vitro and significant prolongation of survival of mice given 50 microg of HuMAb intraperitoneally (i.p.) and 25 ng of Stx2 intravenously. When administered i.p. to gnotobiotic piglets 6 or 12 h after infection with E. coli O157:H7 strain 86-24, HuMAbs 2F10, 3E9, 5H8, and 5C12 prolonged survival and prevented development of fatal neurological signs and cerebral lesions. The Stx2-neutralizing ability of these HuMAbs could potentially be used clinically to passively protect against HUS development in individuals infected with Stx-producing bacteria, including E. coli O157:H7.
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Affiliation(s)
- Jean Mukherjee
- Tufts University School of Veterinary Medicine, North Grafton, Massachusetts 01536, USA
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29
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Döhler JR, Nebermann L. Bovine colostrum in oral treatment of enterogenic endotoxaemia in rats. Crit Care 2002; 6:536-9. [PMID: 12493077 PMCID: PMC153433 DOI: 10.1186/cc1819] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2002] [Revised: 08/07/2002] [Accepted: 08/30/2002] [Indexed: 11/10/2022] Open
Abstract
INTRODUCTION Under conditions of shock, bacteria and endotoxins in the intestines can traverse the mucosal barrier by translocation and enter the blood and lymphatic system. Immunoglobulins and lactoferrin have been reported to neutralize endotoxins and bacteria. We studied the essential therapeutic factors of colostrum products in an animal experiment. METHOD We simulated endotoxaemia by per-oral administration of a suspension of Escherichia coli and antibiotics into the duodenum of anaesthetized rats after giving intraperitoneal carrageenan. At the same time, pure bovine colostrum or lactoferrin-enriched bovine colostrum was given. Therapeutic effects were studied by examining plasma endotoxin activity and bacterial contamination of mesenterial lymph nodes and peritoneal lavages. Albumin was used in a control group. RESULTS The most effective bovine colostrum was able to reduce the maximum plasma endotoxin value by 67% as compared with the albumin group. The combination of this colostrum with lactoferrin brought about a reduction by 80%. The reduction in bacterial contamination of lymph nodes and peritoneal lavages was also evident. CONCLUSION Both gammaglobulin and lactoferrin may help to eliminate endotoxins when bovine colostrum is administered into the gut in conditions of septic shock.
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Affiliation(s)
- J Rüdiger Döhler
- Department of Orthopaedic, Trauma and Hand Surgery, Klinikum Plau am See, Mecklenburg-Vorpommern, Germany.
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30
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Nabuurs MJ, Van De Weijgert EJ, Grootendorst AF, Niewold TA. Oedema disease is associated with metabolic acidosis and small intestinal acidosis. Res Vet Sci 2001; 70:247-53. [PMID: 11676622 DOI: 10.1053/rvsc.2001.0468] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Limited information is available about the pathogenesis and pathophysiology of oedema disease (OD). Oedema disease is caused by specific enterotoxemic Escherichia coli (SLTIIv-toxin producing) strains; however, the same strains are also found in non-afflicted pigs. Furthermore, it is unclear how the 80 kDa SLTIIv-toxin can pass the intestinal barrier. In the present paper, piglets showing signs of acute OD were anaesthetised, instrumented and cardiovascular and intestinal parameters were determined at 0, 1, 2 and 3 hours. Healthy piglets from the same herd were used as a control. Cardiac output, blood pH and bicarbonate, small intestinal intramucosal pH, and (pulmonary) blood pressure were significantly lower in OD-pigs than in control pigs. It is concluded that OD is associated with metabolic and intestinal acidosis. Intestinal acidosis is known to increase macromolecular permeability. This suggests that once OD has developed, influx of SLTIIv-toxin into the blood stream is facilitated, thus perpetuating the disease. Since intestinal permeability appears to be central in OD, it is argued that post-weaning events increase intestinal permeability and predispose individuals to OD.
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Affiliation(s)
- M J Nabuurs
- ID-Lelvstad, Institute of Animal Science and Health, Lelystad, The Netherlands
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