151
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Chapman PA, Ashton R. An evaluation of rapid methods for detecting Escherichia coli O157 on beef carcasses. Int J Food Microbiol 2003; 87:279-85. [PMID: 14527800 DOI: 10.1016/s0168-1605(03)00074-6] [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: 10/27/2022]
Abstract
Numbers of Escherichia coli O157 in food may be low and sensitive techniques are therefore needed for its detection. The objectives of this study were to use carcass meat samples artificially inoculated with various strains of E. coli O157 to compare the sensitivity of enrichment in three different media and to compare immunomagnetic separation followed by culture of magnetic beads to cefixime tellurite sorbitol MacConkey agar with three immunoassays for the detection of E. coli O157 in the enrichment cultures. Duplicate 250, 25 and 2-3 CFU of each of 16 strains of E. coli O157 added to 25-g samples of beef carcass meat were used to compare the sensitivity of (1) enrichment in supplemented tryptone soya broth (sTSB), Reveal 8-h and Reveal 20-h media, and (2) immunomagnetic separation and culture to cefixime tellurite sorbitol MacConkey agar (IMS/CT-SMAC) with Reveal, VIP and STAT immunoassays for detecting the organism. An initial inoculum of 250 CFU/25 g meat was detected in all 32 samples by IMS/CT-SMAC performed on all enrichment media and by Reveal performed on Reveal 8-h and Reveal 20-h media, but in only 30, 19 and 9 samples by Reveal, VIP and STAT, respectively, performed on sTSB medium. An initial inoculum of 25 CFU/25 g meat was detected in 28, 32 and 30 of 32 samples by IMS/CT-SMAC performed on sTSB, Reveal 8-h and Reveal 20-h media, respectively, and in 32 and 30 samples by Reveal performed on Reveal 8-h and Reveal 20-h media, but in only 22, 11 and 2 samples by Reveal, VIP and STAT, respectively, performed on sTSB medium. An initial inoculum of 2-3 CFU/25 g meat was detected in 25, 31 and 28 of 32 samples by IMS/CT-SMAC performed on sTSB, Reveal 8-h and Reveal 20-h media, respectively, and in 25 and 23 samples by Reveal performed on Reveal 8-h and Reveal 20-h media, but in only 14, 1 and 0 samples by Reveal, VIP and STAT, respectively, performed on sTSB medium.
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Affiliation(s)
- P A Chapman
- Public Health Laboratory, Herries Road, S5 7BQ Sheffield, UK.
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152
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Matussek A, Lauber J, Bergau A, Hansen W, Rohde M, Dittmar KEJ, Gunzer M, Mengel M, Gatzlaff P, Hartmann M, Buer J, Gunzer F. Molecular and functional analysis of Shiga toxin-induced response patterns in human vascular endothelial cells. Blood 2003; 102:1323-32. [PMID: 12702508 DOI: 10.1182/blood-2002-10-3301] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Enterohemorrhagic Escherichia coli (EHEC) is the major cause of hemolyticuremic syndrome (HUS) characterized by microangiopathic hemolytic anemia, thrombocytopenia, and acute renal failure. EHEC produces one or more Shiga toxins (Stx1 and Stx2), and it was assumed that Stx's only relevant biologic activity was cell destruction through inhibition of protein synthesis. However, recent data indicate that in vivo the cytokine milieu may determine whether endothelial cells survive or undergo apoptosis/necrosis when exposed to Stxs. In this study, we analyzed the genome-wide expression patterns of human endothelial cells stimulated with subinhibitory concentrations of Stxs in order to characterize the genomic expression program involved in the vascular pathology of HUS. We found that Stxs elicited few, but reproducible, changes in gene expression. The majority of genes reported in this study encodes for chemokines and cytokines, which might contribute to the multifaceted inflammatory response of host endothelial cells observed in patients suffering from EHEC disease. In addition, our data provide for the first time molecular insights into the epidemiologically well-established higher pathogenicity of Stx2 over Stx1.
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Affiliation(s)
- Andreas Matussek
- Department of Microbiology, German Research Centre for Biotechnology, Braunschweig, Germany
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153
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Shimizu K, Asahara T, Nomoto K, Tanaka R, Hamabata T, Ozawa A, Takeda Y. Development of a lethal Shiga toxin-producing Escherichia coli-infection mouse model using multiple mitomycin C treatment. Microb Pathog 2003; 35:1-9. [PMID: 12860453 DOI: 10.1016/s0882-4010(03)00065-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The aim of this study was to develop a lethal Shiga toxin-producing Escherichia coli (STEC) infection model in mice. A small inoculum of 5 x 10(3) CFU of STEC strain 89020087 to mice treated with streptomycin sulfate in drinking water (5 mg/ml) lead to marked increase in the excretion of the bacteria of up to 10(9)CFU/g feces within 18 h after the challenge. Combination of administration of 5 x 10(3) CFU of STEC followed by mitomycin C (MMC) treatment during the late log phase to the early stationary phase of STEC growth in the intestine lead to fatal infection. Periodic analysis showed that there is transient but dramatic increase in the Stxs (Stx1 and Stx2) concentration in the lower intestines after multiple MMC treatment. Histopathological analysis and blood chemistry revealed damages in both kidney and hematopoietic organs but not in the brain. Comparison of the virulence of 11 different STEC strains revealed that only strains which produced high amount of Stx2 responding to MMC treatment and exerted lethal toxicity to mice, suggesting that Stx2 plays a pivotal role in the lethal infection of STEC in the mouse model.
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Affiliation(s)
- Kensuke Shimizu
- Yakult Central Institute for Microbiological Research, 1796 Yaho, Kunitachi-shi, Tokyo 186-8650, Japan
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154
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Sheoran AS, Chapman S, Singh P, Donohue-Rolfe A, Tzipori S. Stx2-specific human monoclonal antibodies protect mice against lethal infection with Escherichia coli expressing Stx2 variants. Infect Immun 2003; 71:3125-30. [PMID: 12761090 PMCID: PMC155773 DOI: 10.1128/iai.71.6.3125-3130.2003] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Shiga toxin-producing Escherichia coli (STEC) strains are responsible for causing hemolytic-uremic syndrome (HUS), and systemic administration of Shiga toxin (Stx)-specific human monoclonal antibodies (HuMAbs) is considered a promising approach for prevention or treatment of the disease in children. The goal of the present study was to investigate the ability of Stx2-specific HuMAbs to protect against infections with STEC strains that produce Stx2 variants. Dose-response studies on five HuMAbs, using the mouse toxicity model, revealed that only the three directed against the A subunit were protective against Stx2 variants, and 5C12 was the most effective among the three tested. Two HuMAbs directed against the B subunit, while highly effective against Stx2, were ineffective against Stx2 variants. In a streptomycin-treated mouse model, parenteral administration of 5C12 significantly protected mice up to 48 h after oral bacterial challenge. We conclude that 5C12, reactive against the Stx2 A subunit, is an excellent candidate for immunotherapy against HUS and that antibodies directed against the A subunit of Stx2 have broad-spectrum activity that includes Stx2 variants, compared with those directed against the B subunit.
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Affiliation(s)
- Abhineet S Sheoran
- Division of Infectious Diseases, Tufts University School of Veterinary Medicine, North Grafton, Massachusetts 01536, USA
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155
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Jenkins C, Pearce MC, Chart H, Cheasty T, Willshaw GA, Gunn GJ, Dougan G, Smith HR, Synge BA, Frankel G. An eight-month study of a population of verocytotoxigenic Escherichia coli (VTEC) in a Scottish cattle herd. J Appl Microbiol 2003; 93:944-53. [PMID: 12452950 DOI: 10.1046/j.1365-2672.2002.01771.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
AIMS Strains of Verocytotoxin-producing Escherichia coli (VTEC) from Scottish beef cattle on the same farm were isolated during four visits over a period of eight months. Characteristics of these strains were examined to allow comparisons with strains of VTEC associated with human infection. METHODS AND RESULTS Strains were characterized to investigate the relationship between these bovine isolates with respect to serotype, Verocytotoxin (VT) type, intimin-type, and presence or absence of the enterohaemolysin genes. VT genes were detected in 176 of 710 (25%) faecal samples tested using PCR, although only 94 (13%) VTEC strains were isolated using DNA probes on cultures. Forty-five different serotypes were detected. Commonly isolated serotypes included O128ab:H8, O26:H11 and O113:H21. VTEC O26:H11 and O113:H21 have been associated with human disease. Strains harbouring the VT2 genes were most frequently isolated during the first three visits to the farm and those with both VT1 and VT2 genes were the major type during the final visit. Of the 94 strains of non-O157 VTEC isolated, 16 (17%) had the intimin gene; nine had the gene encoding beta-intimin and seven strains had an eta/zeta-intimin gene. Forty-one (44%) of 94 strains carried enterohaemolysin genes. CONCLUSIONS Different serotypes and certain transmissible characteristics, such as VT-type and the enterohaemolysin phenotype, appeared to be common throughout the VTEC population at different times. SIGNIFICANCE AND IMPACT OF THE STUDY Detailed typing and subtyping strains of VTEC as described in this study may improve our understanding of the relationship between bovine VTEC and those found in the human population.
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Affiliation(s)
- C Jenkins
- Laboratory of Enteric Pathogens, Central Public Health Laboratory, London, UK
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156
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Misselwitz J, Karch H, Bielazewska M, John U, Ringelmann F, Rönnefarth G, Patzer L. Cluster of hemolytic-uremic syndrome caused by Shiga toxin-producing Escherichia coli O26:H11. Pediatr Infect Dis J 2003; 22:349-54. [PMID: 12690276 DOI: 10.1097/01.inf.0000059338.38673.ae] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BACKGROUND The epidemiology and clinical characteristics of the hemolytic-uremic syndrome (HUS) caused by Escherichia coli O157:H7 are well-known, but HUS attributable to non-O157:H7 Shiga toxin (Stx)-producing E. coli (STEC) are less thoroughly described. Here we report a cluster of HUS cases caused by STEC O26:H11 the most common non-O157:H7 STEC isolated from sporadic cases of HUS in Europe. METHODS Three children between 13 and 17 months of age, living in the same small town, developed HUS within an interval of 5 days. We present clinical and microbiologic data on the patients and their infecting isolates. RESULTS The clinical course ranged from mild uncomplicated HUS to severe HUS complicated by multiorgan involvement. Microbiologic investigation demonstrated STEC of serotype O26:H11 in stools of all the patients. The phenotypic and molecular characterization of the STEC O26:H11 isolates demonstrated that these strains were identical and, unusual for STEC O26, they harbored the stx2 but not the stx1 gene. None of the patients had evidence of STEC O157:H7 infection either by culture or by E. coli O157 serology. The source of the STEC O26:H11 infection was undetermined. CONCLUSIONS Our results demonstrate that diagnostic procedures based on the detection of stx genes and/or Stx production and subsequent subtyping of the isolates using molecular methods are necessary to identify such outbreaks caused by non-O157:H7 STEC.
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Affiliation(s)
- Joachim Misselwitz
- Department of Pediatrics, Children's Hospital of Friedrich-Schiller-University, Kochstrasse 2, D-07745 Jena, Germany.
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157
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Bettelheim KA. Non-O157 verotoxin-producing Escherichia coli: a problem, paradox, and paradigm. Exp Biol Med (Maywood) 2003; 228:333-44. [PMID: 12671176 DOI: 10.1177/153537020322800402] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The problems associated with identification and characterization of non-O157 verotoxin-producing Escherichia coli (VTEC) are discussed. The paradox of VTEC is that most reports of human illnesses are associated with serotypes such as O157:H7, O111:H- (nonmotile), O26:H11, and O113:H21, which are rarely found in domestic animals. However, those VTEC serotypes commonly found in domestic animals, especially ruminants, rarely cause human illnesses. When they cause human illnesses, the symptoms are similar to those caused by the serotypes E. coli O157:H7, O111:H-, O26:H11, and O113:H21. The impact of VTEC on human and animal health is also addressed. The VTEC and their toxicity are considered as a paradigm for emerging pathogens. The question on how such pathogens could arise from a basic commensal population is also addressed.
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Affiliation(s)
- Karl A Bettelheim
- National Escherichia coli Reference Laboratory, Microbiological Diagnostic Unit, Public Health Laboratory, Department of Microbiology and Immunology, University of Melbourne, Parkville, Victoria 3052, Australia.
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158
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Callaway TR, Elder RO, Keen JE, Anderson RC, Nisbet DJ. Forage feeding to reduce preharvest Escherichia coli populations in cattle, a review. J Dairy Sci 2003; 86:852-60. [PMID: 12703622 DOI: 10.3168/jds.s0022-0302(03)73668-6] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Although Escherichia coli are commensal organisms that reside within the host gut, some pathogenic strains of E. coli can cause hemorrhagic colitis in humans. The most notable enterohemorrhagic E. coli (EHEC) strain is O157:H7. Cattle are asymptomatic natural reservoirs of E. coli O157:H7, and it has been reported that as many as 30% of all cattle are carriers of this pathogen, and in some circumstances this can be as high as 80%. Feedlot and high-producing dairy cattle are fed large grain rations in order to increase feed efficiency. When cattle are fed large grain rations, some starch escapes ruminal microbial degradation and passes to the hind-gut where it is fermented. EHEC are capable of fermenting sugars released from starch breakdown in the colon, and populations of E. coli have been shown to be higher in grain fed cattle, and this has been correlated with E. coli O157:H7 shedding in barley fed cattle. When cattle were abruptly switched from a high grain (corn) diet to a forage diet, generic E. coli populations declined 1000-fold within 5 d, and the ability of the fecal generic E. coli population to survive an acid shock similar to the human gastric stomach decreased. Other researchers have shown that a switch from grain to hay caused a smaller decrease in E. coli populations, but did not observe the same effect on gastric shock survivability. In a study that used cattle naturally infected with E. coli O157:H7, fewer cattle shed E. coli O157:H7 when switched from a feedlot ration to a forage-based diet compared with cattle continuously fed a feedlot ration. Results indicate that switching cattle from grain to forage could potentially reduce EHEC populations in cattle prior to slaughter; however the economic impact of this needs to be examined.
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Affiliation(s)
- T R Callaway
- Food and Feed Safety Research Unit, South Plains Agricultural Research Center, Agricultural Research Service, USDA, College Station, TX 77845, USA.
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159
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Bettelheim KA, Hornitzky MA, Djordjevic SP, Kuzevski A. Antibiotic resistance among verocytotoxigenic Escherichia coli (VTEC) and non-VTEC isolated from domestic animals and humans. J Med Microbiol 2003; 52:155-162. [PMID: 12543922 DOI: 10.1099/jmm.0.04903-0] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Two hundred verocytotoxigenic and 216 non-verocytotoxigenic Escherichia coli (VTEC and non-VTEC), isolated from a variety of sources were tested for their resistances to 11 antimicrobial agents. The strains included isolates from domestic food animals and both symptomatic and asymptomatic infections in man. A much higher level of resistance was found among the non-VTEC than among the VTEC, regardless of source. The resistant VTEC isolated from animals were predominantly from specimens associated with sick animals. Antibiotic resistance was detected in only four of the 59 (6.8 %) VTEC of human origin, whereas more of the human non-VTEC possessed antibiotic resistance determinants. It was particularly noteworthy that 24/87 (28 %) strains isolated from healthy babies, who had neither contact with antibiotics nor had gastrointestinal symptoms for at least 2 weeks prior to the specimen being taken, were resistant to one or more of the antibiotics tested.
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Affiliation(s)
- Karl A Bettelheim
- Microbiological Diagnostic Unit, Public Health Laboratory, Department of Microbiology and Immunology, University of Melbourne, Royal Parade, Parkville, Victoria, Australia 3052 2Elizabeth Macarthur Agricultural Institute, Private Mail Bag 8, Camden, New South Wales, Australia 2570
| | - Michael A Hornitzky
- Microbiological Diagnostic Unit, Public Health Laboratory, Department of Microbiology and Immunology, University of Melbourne, Royal Parade, Parkville, Victoria, Australia 3052 2Elizabeth Macarthur Agricultural Institute, Private Mail Bag 8, Camden, New South Wales, Australia 2570
| | - Steven P Djordjevic
- Microbiological Diagnostic Unit, Public Health Laboratory, Department of Microbiology and Immunology, University of Melbourne, Royal Parade, Parkville, Victoria, Australia 3052 2Elizabeth Macarthur Agricultural Institute, Private Mail Bag 8, Camden, New South Wales, Australia 2570
| | - Alexander Kuzevski
- Microbiological Diagnostic Unit, Public Health Laboratory, Department of Microbiology and Immunology, University of Melbourne, Royal Parade, Parkville, Victoria, Australia 3052 2Elizabeth Macarthur Agricultural Institute, Private Mail Bag 8, Camden, New South Wales, Australia 2570
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160
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Hornitzky MA, Vanselow BA, Walker K, Bettelheim KA, Corney B, Gill P, Bailey G, Djordjevic SP. Virulence properties and serotypes of Shiga toxin-producing Escherichia coli from healthy Australian cattle. Appl Environ Microbiol 2002; 68:6439-45. [PMID: 12450875 PMCID: PMC134377 DOI: 10.1128/aem.68.12.6439-6445.2002] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2002] [Accepted: 09/23/2002] [Indexed: 12/28/2022] Open
Abstract
The virulence properties and serotypes of complex Shiga toxin-producing Escherichia coli (cSTEC) were determined in two studies of healthy cattle in eastern Australia. In the first, a snapshot study, 84 cSTEC isolates were recovered from 37 of 1,692 (2.2%) fecal samples collected from slaughter-age cattle from 72 commercial properties. The second, a longitudinal study of three feedlots and five pasture beef properties, resulted in the recovery of 118 cSTEC isolates from 104 animals. Of the 70 serotypes identified, 38 had not previously been reported.
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Affiliation(s)
- Michael A Hornitzky
- Elizabeth Macarthur Agricultural Institute, New South Wales Agriculture, Camden, Australia.
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161
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Vernozy-Rozand C, Ray-Gueniot S, Ragot C, Bavai C, Mazuy C, Montet MP, Bouvet J, Richard Y. Prevalence of Escherichia coli O157:H7 in industrial minced beef. Lett Appl Microbiol 2002; 35:7-11. [PMID: 12081541 DOI: 10.1046/j.1472-765x.2002.01116.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
AIMS The lack of baseline data on the prevalence of Escherichia coli O157:H7 in retail minced beef in France prompted this survey of industrial minced beef production. METHODS AND RESULTS An automated enzyme-linked fluorescence immunoassay (ELFA), the VIDAS E. coli O157 method, was used to detect E. coli O157 in industrial minced beef samples. Confirmation of samples positive according to the ELFA was performed using an automated immunoconcentration (ICE) system, VIDAS ICE, which allows the selective capture and release of target organisms. The ICE was followed by culture on cefixime tellurite sorbitol MacConkey agar and a chromogenic medium, O157:H7 ID. Of the 3450 minced beef samples tested, 175 samples were positive with the ELFA method and, of these, four were confirmed by the ICE method. They were identified as sorbitol-negative, O157-positive, H7-positive, mobile, verotoxin-producing E. coli. CONCLUSIONS The prevalence of E. coli O157:H7 in industrial French minced beef was 0.12%, consistent with many other reports. SIGNIFICANCE AND IMPACT OF THE STUDY The low infective dose of E. coli O157:H7 presents a major threat. The main means of combating this organism are thermal destruction and good food hygiene covering activities on-farm, in the abattoir and in minced beef industries.
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Affiliation(s)
- C Vernozy-Rozand
- Unité de Microbiologie Alimentaire et Prévisionnelle, Ecole Nationale Vétérinaire de Lyon, Marcy I'Etoile, France.
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162
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Orden JA, Cid D, Ruiz-Santa-Quiteria JA, García S, Martínez S, de la Fuente R. Verotoxin-producing Escherichia coli (VTEC), enteropathogenic E. coli (EPEC) and necrotoxigenic E. coli (NTEC) isolated from healthy cattle in Spain. J Appl Microbiol 2002; 93:29-35. [PMID: 12067371 DOI: 10.1046/j.1365-2672.2002.01649.x] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
AIMS To determine the prevalence and characteristics of verotoxigenic Escherichia coli (VTEC), enteropathogenic E. coli (EPEC) and necrotoxigenic E. coli (NTEC) in healthy cattle. METHODS AND RESULTS Faecal samples from 412 healthy cattle were screened for the presence of VTEC, EPEC and NTEC. Four isolates from each sample were studied. VTEC, EPEC and NTEC were isolated in 8.7%, 8.2% and 9.9% of the animals, respectively. VTEC and NTEC were isolated more frequently from calves and heifers than from adults. Seventy (4.2%), 69 (4.2%) and 74 (4.5%) of the 1648 E. coli isolates were VTEC, EPEC and NTEC, respectively. Seventeen (24.3%) of the VTEC strains were eae-positive. Thirty-six (51.4%) of VTEC strains belonged to E. coli serogroups associated with haemorrhagic colitis and haemolytic uraemic syndrome in humans. The serogroups most prevalent among the EPEC strains were O10, O26, O71, O145 and O156. CONCLUSIONS Healthy cattle are a reservoir of VTEC, EPEC and NTEC. SIGNIFICANCE AND IMPACT OF THE STUDY Although most of the VTEC strains were eae-negative, a high percentage of VTEC strains belonged to serogroups associated with severe disease in humans.
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Affiliation(s)
- J A Orden
- Departamento de Patología Animal I, Facultad de Veterinaria, Universidad Complutense, Madrid, Spain
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163
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Klein EJ, Stapp JR, Clausen CR, Boster DR, Wells JG, Qin X, Swerdlow DL, Tarr PI. Shiga toxin-producing Escherichia coli in children with diarrhea: a prospective point-of-care study. J Pediatr 2002; 141:172-7. [PMID: 12183710 DOI: 10.1067/mpd.2002.125908] [Citation(s) in RCA: 105] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVE To conduct a prospective cohort study to determine the frequency and characteristics of Shiga toxin (Stx)-producing Escherichia coli (STEC) infections in children with diarrhea attending an emergency department and a private clinic in Seattle, Washington. METHODS Between November 1998 and October 2001, 1851 stools were processed for STEC by sorbitol-MacConkey (SMAC) agar screening and a commercial Stx enzyme immunoassay (EIA). RESULTS STEC belonging to serotypes O157:H7 (n = 28), O103:H2 (n = 4), O118:H16 (n = 2), O26:H11, O111:nonmotile, O111:H8, O121:H19, and O rough:H11 (n = 1 each) were recovered from 39 (2.1%) stools. EIA and SMAC agar detected 89% and 100% of the patients with E coli O157:H7, respectively. E coli O157:H7-infected patients had significantly higher frequencies of bloody stools, fecal leukocytes, and abdominal tenderness and shorter symptom duration. Hemolytic uremic syndrome developed in 5 (18%) and none of the children infected with E coli O157:H7 and non-O157:H7 STEC, respectively (P =.30). CONCLUSIONS E coli O157:H7 is the predominant STEC in this population. Children infected with E coli O157:H7 have clinical presentations different from those whose stools contain non-O157:H7 STEC. Culture and Stx detection are needed to optimally detect STEC of all serotypes in stools. SMAC agar screening should not be replaced by EIA.
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Affiliation(s)
- Eileen J Klein
- Department of Pediatrics, University of Washington and Children's Hospital and Regional Medical Center, Seattle, Washington, 98105, USA
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164
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Kulkarni H, Goldwater PN, Martin A, Bettelheim KA. Escherichia coli 'O' group serological responses and clinical correlations in epidemic HUS patients. Comp Immunol Microbiol Infect Dis 2002; 25:249-68. [PMID: 12135239 DOI: 10.1016/s0147-9571(02)00011-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
This first comprehensive serological analysis of an haemolytic uraemic syndrome (HUS) outbreak in which a wide range of 'O' group Escherichia coli antibody responses in patients and controls provided a unique insight into the epidemiology of such epidemics. Possible answers to clinical aspects related to severity of disease and complications were revealed. A microagglutination assay was used to examine E. coli 'O' group serological responses in 49 serum samples of 21 children hospitalised with HUS and 14 single samples from contemporaneous age-matched controls. A total of 51 O serogroup strains were used, including those reported to be associated with cases of HUS, with six isolates from patients associated with the Adelaide outbreak, environmental verocytotoxi-genic/shiga-toxin producing E. coli (VTEC/STEC) strains and common human commensal strains. Amongst the 21 patients, there were 226 instances of seroreactivity (titre > or = 100) against 34 E. coli serogroups while six instances of seroreactivity against four serogroups occurred in controls. There were 128 instances in patients and one instance in controls in which titres > or = 400 were observed. All 21 patients were seroreactive (titre > or = 100 and <400) to one or more of the 17 HUS-associated serogroups included in the study. Titres ranged from 100 to 6,400, some of the highest in three patients were against O157, whose faeces yielded only EHEC O111, and only one developed O111 antibody. Mixed infection was demonstrated serologically by microagglutination (confirmed by western blot) and was consistent with the multiple serogroups of VTEC found in the mettwurst incriminated as the source, and suggests further strains (not found in the source or in patients' faeces) were probably involved. In HUS-associated EHEC infection, multiple strain infection may be the rule rather than the exception. Analysis of 34 of the 51 serogroup antibody responses in the HUS patients revealed clues to possible relationships with clinical severity and complications. Patients with severe renal failure tended to develop antibodies to a larger number of serogroups than those with moderate or mild impairment. The same was true for central nervous system complications. Other associations were observed. While VTEC O157 remains an important causal serogroup in HUS, non-O157 serogroups also appear to play a significant role and therefore the latter should always be sought in all future HUS cases as new insights into pathogenicity may be discovered. This study indicates that co-infection with different VTEC serogroups may affect clinical outcome.
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Affiliation(s)
- Hemant Kulkarni
- Department of Nephrology, Women's and Children's Hospital, North Adelaide, SA, Australia
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165
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Paton AW, Paton JC. Reactivity of convalescent-phase hemolytic-uremic syndrome patient sera with the megaplasmid-encoded TagA protein of Shiga toxigenic Escherichia coli O157. J Clin Microbiol 2002; 40:1395-9. [PMID: 11923363 PMCID: PMC140373 DOI: 10.1128/jcm.40.4.1395-1399.2002] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A cosmid library of Shiga toxigenic Escherichia coli (STEC) O157:H7 strain EDL933 DNA was screened for clones capable of reacting with convalescent-phase serum from a patient with hemolytic-uremic syndrome (HUS), in an attempt to identify candidate virulence genes. One of the immunoreactive clones contained a portion of the large plasmid pO157, and the immunoreactive gene product was identified as TagA. The function of this 898-amino-acid protein is unknown, but it exhibits 42% amino acid sequence identity and 63% similarity to a 312-amino-acid region of a ToxR-regulated lipoprotein of Vibrio cholerae. Antibodies to E. coli O157 TagA were detected in sera from other HUS patients with O157 STEC infection but not in those from patients whose illnesses were caused by other STEC types or in healthy controls. These data demonstrate that TagA is expressed in vivo and provide circumstantial evidence for a role in the pathogenesis of the disease. The tagA gene is present only in STEC strains belonging to serogroup O157, and so antibodies to TagA are a potentially useful serological marker for infections due to such strains.
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Affiliation(s)
- Adrienne W Paton
- Department of Molecular Biosciences, Adelaide University, Adelaide, S.A., 5005, Australia
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166
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Piérard D, Stevens D, Moriau L, Lior H, Lauwers S. Isolation and virulence factors of verocytotoxin-producing Escherichia coli in human stool samples. Clin Microbiol Infect 2002; 3:531-540. [PMID: 11864177 DOI: 10.1111/j.1469-0691.1997.tb00303.x] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVE: To evaluate the isolation rate of O157 and non-O157 verocytotoxin-producing Escherichia coli (VTEC) strains, to study the occurrence of additional virulence factors and to correlate these with clinical symptoms. METHODS: Over more than 5 years, 17 296 unduplicated fecal samples submitted for routine culture were screened for VTEC by a single PCR detecting VT1, VT2 and its variants. Verocytotoxin B subunit genotypes of the isolates obtained by testing individual colonies in positive samples were determined by a polymerase chain reaction---restriction fragment length polymorphism (PCR---RFLP) technique, the eaeA gene and the 60-MDa virulence plasmid by PCR, and the hemolytic phenotype by using CaCl2-washed blood agar. RESULTS: Verocytotoxin genes were found in 1.02% of the samples. Non-O157 VTEC strains were isolated in 0.66% and O157 in 0.17%. Overall, VTEC was less frequently isolated than Campylobacter and Salmonella but more frequently than Yersinia and Shigella. All cases except two siblings were epidemiologically unrelated. Cases of hemolytic uremic syndrome (HUS) were only observed in association with serogroup O157, which seems to be more pathogenic than the non-O157 strains. Among non-O157 VTEC strains, eaeA-positive strains are more frequently associated with clinical symptoms than are eaeA-negative strains. Other virulence factors correlate less closely with the presence of symptoms. CONCLUSIONS: VTEC is the third bacterial intestinal pathogen in our study population. All stool samples from patients with diarrhea should be screened for the most frequent serogroup, O157, or, if this is not possible, at least those from patients with bloody diarrhea. Non-O157 VTEC strains, especially if they are eaeA positive, are also associated with diarrhea, more often non-bloody. PCR or the new commercially available immunoassays could be used in selected cases, e.g. in patients suffering from HUS and in cases of outbreaks.
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Affiliation(s)
- Denis Piérard
- Department of Microbiology, Akademisch Ziekenhuis Vrije Universiteit Brussel, Brussels, Belgium
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167
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Abstract
Non-O157 VTEC are typical Escherichia coli that differ only in their ability to produce verocytotoxins (VT). The transmission of VTEC is discussed in relation to the transmission of commensal E. coli. The emergence over the last few decades of a great variety of VTEC serotypes from healthy and diseased humans and animals is described. Particular attention is given to the distribution of the more important serogroups pathogenic for humans that have been described from around the world, particularly serogroups O26, O111, O128 and O103. The possible role of ruminants as reservoirs is discussed. The problems of laboratory diagnosis of non-O157 VTEC are considered and various laboratory methods are assessed. Evidence is presented that the particular E. coli serotypes now known to be VTEC were present in humans and animals many years ago, but have acquired the ability to produce VT and probably other virulence factors. Finally, predictions are made of the possible increase in problems associated with these emerging pathogens.
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Affiliation(s)
- K A Bettelheim
- National Escherichia coli Reference Laboratory, Victorian Infectious Diseases Reference Laboratory, Carlton South, Victoria, Australia
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168
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Tarr CL, Whittam TS. Molecular evolution of the intimin gene in O111 clones of pathogenic Escherichia coli. J Bacteriol 2002; 184:479-87. [PMID: 11751825 PMCID: PMC139570 DOI: 10.1128/jb.184.2.479-487.2002] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Intimin is an important virulence factor in two groups of enteric pathogens: enteropathogenic Escherichia coli (EPEC), which is a major cause of infant diarrhea in the developing world, and enterohemorrhagic E. coli (EHEC), which has caused large food-borne outbreaks of hemorrhagic colitis in the United States and other developed countries. Intimin is encoded on a 35-kb pathogenicity island called the locus of enterocyte effacement (LEE). At least five antigenic types have been described for the highly variable gene, and each type is generally characteristic of particular evolutionary lineages. We determined the nucleotide sequences of intimin and other LEE genes in two O111 clones that have not been amenable to typing. The sequences from both O111:H8 and O111:H9 differed from the Int-beta that is typical of other clones in the same evolutionary lineage. The sequence from the O111:H8 strains was a mosaic of divergent segments that alternately clustered with Int-alpha, Int-beta, or Int-gamma. The sequence from the O111:H9 clone consistently showed a close relationship with that from E2348/69, a distantly related strain that expresses Int-alpha. The results suggest that there have been multiple acquisitions of the LEE in the EHEC 2/EPEC 2 clonal lineage, with a recent turnover in either O111:H8 or its close relatives. Amino acid substitutions that alter residue charge occurred more frequently than would be expected under random substitution in the extracellular domains of intimin, suggesting that diversifying selection has promoted divergence in this region of the protein. An N-terminal domain that presumably functions in the periplasm may also be under positive selection.
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Affiliation(s)
- Cheryl L Tarr
- Microbial Evolution Laboratory, National Food Safety and Toxicology Center, Michigan State University, East Lansing, Michigan 48824, USA
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169
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170
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Hogan MC, Gloor JM, Uhl JR, Cockerill FR, Milliner DS. Two cases of non-O157:H7 Escherichia coli hemolytic uremic syndrome caused by urinary tract infection. Am J Kidney Dis 2001; 38:E22. [PMID: 11576909 DOI: 10.1053/ajkd.2001.27731] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Escherichia coli serotype O157:H7 is a leading cause of diarrhea and hemolytic uremic syndrome (HUS). Because of the limitations of current diagnostic techniques, the prevalence of non-O157:H7 Shiga toxin-producing E coli strains is not known. We describe two patients with HUS in whom no E coli O157:H7 was demonstrable in stool cultures. On culture of the urine, the first patient was found to have E coli O113:H21 strain, and the second patient had E coli O6:H1 serotype. Shiga toxin production (stx2) by the O113:H21 isolate was confirmed. The first patient required 15 days of peritoneal dialysis and subsequently recovered renal function. At last follow-up, serum creatinine was 0.9 mg/dL. The second patient had preservation of renal function throughout the acute illness with serum creatinine of 0.5 mg/dL. The clinical presentation, bacteriology, course, and outcome as well as epidemiologic implications of the increasing number of patients with E coli urinary tract infections associated with HUS are discussed. These cases illustrate the need to investigate patients with nondiarrheal HUS for infection with Shiga toxin-producing E coli of the non-O157 strain variety.
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Affiliation(s)
- M C Hogan
- Department of Internal Medicine, Division of Nephrology, Mayo Clinic, Rochester, MN 55905, USA.
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171
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Chinen I, Tanaro JD, Miliwebsky E, Lound LH, Chillemi G, Ledri S, Baschkier A, Scarpin M, Manfredi E, Rivas M. Isolation and characterization of Escherichia coli O157:H7 from retail meats in Argentina. J Food Prot 2001; 64:1346-51. [PMID: 11563511 DOI: 10.4315/0362-028x-64.9.1346] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Between February and May 2000, 279 meat samples were collected from 136 retail stores in Gualeguaychú City, Argentina. Samples were assayed for Escherichia coli O157:H7 by selective enrichment in modified EC broth containing novobiocin, followed by immunomagnetic separation (IMS) and plating onto both sorbitol MacConkey agar supplemented with cefixime and potassium tellurite and a chromogenic medium. Eleven E. coli O157:H7 isolates were detected in 6 (3.8%) of 160 ground beef samples, in 4 (4.8%) of 83 fresh sausages, and in 1 (3.3%) of 30 dry sausages. E. coli O157:H7 was not isolated from five hamburger patties or one barbecue-type fresh sausage assayed. The isolates were tested for virulence-related genes. Ten additional Shiga toxin-producing E. coli (STEC) O157:H7 isolates of food origin, recovered from different locations in Argentina, were included for comparison purposes. All 21 isolates harbored both eae and EHEC-hlyA genes, and 12 (57.1%) encoded stx2/stx2vh-a. The isolates were of phage types 87 (seven strains), 14 (four strains), 4 (three strains), and 26 (one strain). Six strains were nontypable by phage typing. Pulsed-field gel electrophoresis (PFGE) revealed 19 XbaI-PFGE profiles. Fifteen (71%) strains were grouped in four clusters, which shared more than 80% of DNA restriction fragments. The enrichment culture method with IMS was a sensitive procedure to detect E. coli O157:H7 strains in retail meats. Some of the isolates from different stores presented a high clonal relatedness, as determined by XhaI-PFGE and phage typing, and harbored the virulence factors associated with human illness.
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Affiliation(s)
- I Chinen
- Servicio Fisiopatogenia, Instituto Nacional de Enfermedades Infecciosas-ANLIS Carlos G. Malbrán, Buenos Aires, Argentina
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172
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Chapman PA, Ellin M, Ashton R, Shafique W. Comparison of culture, PCR and immunoassays for detecting Escherichia coli O157 following enrichment culture and immunomagnetic separation performed on naturally contaminated raw meat products. Int J Food Microbiol 2001; 68:11-20. [PMID: 11545210 DOI: 10.1016/s0168-1605(01)00464-0] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The aims of this study were (i) to evaluate the specificity and sensitivity of three previously described PCR assays for the detection of Escherichia coli O157 and, (ii) to compare PCR, culture, and two visual immunoassays (VIAs), BioSign and Path-Stik, for detecting E. coli O157 after enrichment culture and immunomagnetic separation (IMS) performed on various naturally contaminated raw beef, lamb and mixed meat products. Twelve sorbitol nonfermenting (SNF) verocytotoxin-producing (VT +) E. coli O157, 6 SNF VT - E. coli O157, 4 sorbitol fermenting (SF) VT + E. coli O157, 3 SF VT - E. coli O157, 23 E. coli belonging to 17 other serogroups and 12 organisms of other species were used to check the specificity of PCR reactions. Only one primer pair generated amplimers only with E. coli O157 and was used for all subsequent work. After enrichment culture and on inoculated minced beef samples, PCR was as sensitive as culture for detecting 9 of the 12 strains of E. coli O157, but up to 4 log10 more sensitive than culture for detecting three strains. Of the 120 samples of naturally contaminated meat products examined, 80 (67%) were positive by PCR, 70 (58%) were positive by BioSign, 69 (58%) were positive by culture and 67 (56%) were positive by Path-Stik. Although both VIAs lacked sensitivity when compared to PCR, both compared favourably with culture and both were extremely rapid and easy to perform, giving a result in less than 15 min. Eleven samples were positive by PCR and both VIAs, but negative by culture because culture plates were heavily overgrown with SF organisms, making detection of any E. coli O157 present impossible.
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173
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Elliott EJ, Robins-Browne RM, O'Loughlin EV, Bennett-Wood V, Bourke J, Henning P, Hogg GG, Knight J, Powell H, Redmond D. Nationwide study of haemolytic uraemic syndrome: clinical, microbiological, and epidemiological features. Arch Dis Child 2001; 85:125-31. [PMID: 11466187 PMCID: PMC1718875 DOI: 10.1136/adc.85.2.125] [Citation(s) in RCA: 147] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AIMS To establish the incidence and aetiology of haemolytic uraemic syndrome (HUS) in Australia and compare clinical and microbial characteristics of sporadic and outbreak cases. METHODS National active surveillance through the Australian Paediatric Surveillance Unit with monthly case notification from paediatricians, July 1994 to June 1998. Children under 15 years presenting with microangiopathic haemolytic anaemia, thrombocytopenia, and acute renal impairment were identified. RESULTS Ninety eight cases were identified (incidence 0.64 per 10(5) children <15 years/annum and 1.35 per 10(5) children <5 years/annum). Eighty four were associated with diarrhoea (64 sporadic, 20 constituting an outbreak) and 14 were atypical. Shiga toxin producing Escherichia coli (STEC) O111:H- was the most common isolate in sporadic HUS and caused the outbreak. However O111:H- isolates from outbreak and sporadic cases differed in phage type and subtyping by DNA electrophoresis. STEC isolates from sporadic cases included O26:H-, O113:H21, O130:H11, OR:H9, O157:H-, ONT:H7, and ONT:H-. STEC O157:H7 was not isolated from any case. Only O111:H- isolates produced both Shiga toxins 1 and 2 and possessed genes encoding E coli attaching and effacing gene (intimin) and enterohemolysin. Outbreak cases had worse gastrointestinal and renal disease at presentation and more extrarenal complications. CONCLUSIONS Linking national surveillance with a specialised laboratory service allowed estimation of HUS incidence and provided information on its aetiology. In contrast to North America, Japan, and the British Isles, STEC O157:H7 is rare in Australia; however, non-O157:H7 STEC cause severe disease including outbreaks. Disease severity in outbreak cases may relate to yet unidentified virulence factors of the O111:H- strain isolated.
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Affiliation(s)
- E J Elliott
- Department of Paediatrics and Child Health, University of Sydney and The Children's Hospital at Westmead, Sydney, Australia.
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174
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Eklund M, Scheutz F, Siitonen A. Clinical isolates of non-O157 Shiga toxin-producing Escherichia coli: serotypes, virulence characteristics, and molecular profiles of strains of the same serotype. J Clin Microbiol 2001; 39:2829-34. [PMID: 11473999 PMCID: PMC88246 DOI: 10.1128/jcm.39.8.2829-2834.2001] [Citation(s) in RCA: 105] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
All human Shiga toxin-producing Escherichia coli (STEC) non-O157 strains (n = 56) isolated in Finland from 1990 to August 2000 were characterized for the O:H serotype, stx(1) and stx(2) genes, production of enterohemolysin, and sensitivity to 12 antimicrobial agents. Strains of the same serotype were genotyped by pulsed-field gel electrophoresis (PFGE) after XbaI restriction of total DNA. The 56 non-O157 isolates belonged to 29 serotypes. Two of the serotypes (O102:H7 and OX181:H49) have not previously been described as being associated with STEC infections in humans or isolated from animals. Thirty-four strains (61%) within seven serotypes (O103:H2 [14 isolates], O26:H11 [6 isolates], O145:H28 [4 isolates], O145:HNM [3 isolates], O15:HNM [3 isolates], OX174:H21 [2 isolates], and O Rough:HNM [2 isolates]) were represented by more than one isolate. Of these strains, O103:H2 isolates were divided into seven, O26:H11 isolates were divided into four, and the rest within a serotype were divided into two genotypes in PFGE. In PCR, 31 (55%) of the 56 strains were positive for the stx(2) gene only and 24 strains (43%) were positive for stx(1) only. One strain (O43:H2) carried both stx(1) and stx(2). Forty-two strains (75%) produced enterohemolysin, and 39 strains (70%) possessed the eae gene. Of the latter 39 strains, 36 (92%) were enterohemolytic, whereas only 6 (35%) of the 17 isolates lacking the eae gene were enterohemolytic (P < 0.001). The majority of the strains (44 strains, 79%) were sensitive to all 12 antimicrobials tested. Of the 56 strains, 20 (36%) were associated with small family outbreaks in nine families and 14 (25%) were associated with recent travel abroad.
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Affiliation(s)
- M Eklund
- Laboratory of Enteric Pathogens, National Public Health Institute, FIN-00300 Helsinki, Finland
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175
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Paton JC, Rogers TJ, Morona R, Paton AW. Oral administration of formaldehyde-killed recombinant bacteria expressing a mimic of the Shiga toxin receptor protects mice from fatal challenge with Shiga-toxigenic Escherichia coli. Infect Immun 2001; 69:1389-93. [PMID: 11179303 PMCID: PMC98032 DOI: 10.1128/iai.69.3.1389-1393.2001] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Gastrointestinal disease caused by Shiga toxin-producing Escherichia coli (STEC) is frequently complicated by life-threatening toxin-induced systemic sequelae, including the hemolytic uremic syndrome. We previously constructed a recombinant bacterium displaying a Shiga toxin receptor mimic on its surface which neutralized Shiga toxins with very high efficiency. Moreover, oral administration of the live bacterium completely protected mice from challenge with virulent STEC. In this study, we investigated the protective capacity of formaldehyde-killed receptor mimic bacteria, as these are likely to be safer for administration to humans. The killed bacteria completely protected STEC-challenged mice when administered three times daily; incomplete protection was achieved using two doses per day. Commencement of therapy could be delayed for up to 48 h after challenge without diminishing protection, depending on the virulence of the challenge strain. Thus, administration of this agent early in the course of human STEC disease may prevent progression to life-threatening complications.
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Affiliation(s)
- J C Paton
- Molecular Microbiology Unit, Women's and Children's Hospital, North Adelaide, South Australia 5006
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176
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Survival and detection of Escherichia coli O157:H7 and Listeria monocytogenes during the manufacture of dry sausage using two different starter cultures. Food Microbiol 2001. [DOI: 10.1006/fmic.2000.0373] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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177
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Ogawa M, Shimizu K, Nomoto K, Takahashi M, Watanuki M, Tanaka R, Tanaka T, Hamabata T, Yamasaki S, Takeda Y. Protective effect of Lactobacillus casei strain Shirota on Shiga toxin-producing Escherichia coli O157:H7 infection in infant rabbits. Infect Immun 2001; 69:1101-8. [PMID: 11160007 PMCID: PMC97991 DOI: 10.1128/iai.69.2.1101-1108.2001] [Citation(s) in RCA: 111] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
We examined colonization patterns of Shiga toxin-producing Escherichia coli (STEC), concentrations of Shiga toxins (Stxs) and specific immunoglobulin A (lgA) against Stxs and STEC bacterial cell surface antigen in various portions of the gastrointestinal tract in an infant rabbit infection model. After inoculation of 3-day-old infant rabbits with STEC strain 89020087 at low doses (approximately 10(3) CFU/body), numbers of colonizing STEC bacteria and concentrations of Stxs in the intestine increased dramatically and the animals developed diarrhea within a couple of days after infection. Daily administration of Lactobacillus casei from the day of birth dramatically decreased the severity of diarrhea and lowered STEC colonization levels in the gastrointestinal tract 100-fold day 7 after infection. Both Stx1 and Stx2 concentrations in the intestines and histological damage to the intestinal mucus induced by STEC infection were decreased by the administration of L. casei. Examination of the concentrations of volatile fatty acids and pH of the intestinal contents revealed that the protective effect of L. casei administration against STEC infection was not due to fermented products such as lactic acid in the gastrointestinal tract. Administration of L. casei increased levels of lgAs against Stx1, Stx2, and formalin-killed STEC cells in the colon approximately two-, four-, and threefold, respectively, compared with those of the untreated controls by day 7 after infection. These results suggest that administration of L. casei strain Shirota enhances the local immune responses to STEC cells and Stxs and leads to elimination of STEC and thus decreases Stx concentrations in the intestines.
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Affiliation(s)
- M Ogawa
- Yakult Central Institute for Microbiological Research, 1796 Yaho, Kunitachi, Tokyo 186-8650, Japan
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178
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Affiliation(s)
- H J Koornhof
- Department of Clinical Microbiology and Infectious Diseases, South African Institute for Medical Research, Johannesburg, South Africa
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179
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Kobayashi H, Shimada J, Nakazawa M, Morozumi T, Pohjanvirta T, Pelkonen S, Yamamoto K. Prevalence and characteristics of shiga toxin-producing Escherichia coli from healthy cattle in Japan. Appl Environ Microbiol 2001; 67:484-9. [PMID: 11133487 PMCID: PMC92607 DOI: 10.1128/aem.67.1.484-489.2001] [Citation(s) in RCA: 129] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The prevalence of Shiga toxin-producing Escherichia coli (STEC) in Japan was examined by using stool samples from 87 calves, 88 heifers, and 183 cows on 78 farms. As determined by screening with stx-PCR, the prevalence was 46% in calves, 66% in heifers, and 69% in cows; as determined by nested stx-PCR, the prevalence was 100% in all animal groups. Of the 962 isolates picked by colony stx hybridization, 92 isolates from 54 farms were characterized to determine their O serogroups, virulence factor genes, and antimicrobial resistance. Of these 92 isolates, 74 (80%) could be classified into O serogroups; 50% of these 74 isolates belonged to O serogroups O8, O26, O84, O113, and O116 and 1 isolate belonged to O serogroup O157. Locus of enterocyte effacement genes were detected in 24% of the isolates, and enterohemorrhagic E. coli (EHEC) hlyA genes were detected in 72% of the isolates. Neither the bundle-forming pilus gene nor the enteropathogenic E. coli adherence factor plasmid was found. STEC strains with characteristics typical of isolates from human EHEC infections, which were regarded as potential EHEC strains, were present on 11.5% of the farms.
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Affiliation(s)
- H Kobayashi
- National Institute of Animal Health, 3-1-1, Kannondai, Tsukuba 305-0856, Japan.
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180
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Bellin T, Pulz M, Matussek A, Hempen HG, Gunzer F. Rapid detection of enterohemorrhagic Escherichia coli by real-time PCR with fluorescent hybridization probes. J Clin Microbiol 2001; 39:370-4. [PMID: 11136804 PMCID: PMC87735 DOI: 10.1128/jcm.39.1.370-374.2001] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In this report, we present a PCR protocol for rapid identification of enterohemorrhagic Escherichia coli on a LightCycler instrument. In a multiplex assay, the genes encoding Shiga toxin 1 and Shiga toxin 2 are detected in a single reaction capillary. A complete analysis of up to 32 samples takes about 45 min.
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Affiliation(s)
- T Bellin
- Hannover Medical School, Institute of Medical Microbiology, 30625 Hannover, Germany
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181
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Osek J, Gallien P, Protz D. Characterization of shiga toxin-producing Escherichia coli strains isolated from calves in Poland. Comp Immunol Microbiol Infect Dis 2000; 23:267-76. [PMID: 11038128 DOI: 10.1016/s0147-9571(00)00008-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Fecal samples from 67 3-5-months-old calves with diarrhea were screened for the presence of shiga toxin-producing Escherichia coli (STEC). Several accessory virulence factors genes were also tested. Among 192 E. coli isolates tested, 15 (7.6%) were found to harbour the shiga toxin 1 or 2 (stx1 or stx2) genes. The stx2-carrying samples were further subtyped by PCR for the stx2c, stx2d, and stx2e toxin variants. It was shown that stx2-positive bacteria mainly possessed the stx2c shiga toxin type gene. The enterohemolysin (hlyA) and intimin (eae) genes were found in seven (46.7%) STEC strains whereas the cytotoxic necrotizin factor 1 and 2 or the P fimbrial genes were detected in two isolates only. This study confirmed that calves are a reservoir of STEC strains (with all pathogenicity genes) that may be virulent for humans.
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Affiliation(s)
- J Osek
- National Veterinary Research Institute, Pulawv, Poland.
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182
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Cocolin L, Manzano M, Cantoni C, Comi G. A multiplex-PCR method to detect enterohemorrhagic (EHEC) and enteropathogenic (EPEC) Escherichia coli in artificially contaminated foods. Int J Hyg Environ Health 2000; 203:159-64. [PMID: 11109569 DOI: 10.1078/s1438-4639(04)70022-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
In view of the considerable public health risk of the enteropathogenic (EPEC) and enterohemorrhagic (EHEC) Escherichia coli, a multiplex-PCR based method was used for the amplification of the slt genes and of the eaeA gene. Three pairs of primers, different from the oligonucleotides previously used by other authors, were exploited for the amplification. Different E. coli serotypes were tested with the optimized protocol. Fifty three artificially contaminated samples and sixty naturally contaminated samples were processed with the multiplex-PCR. All the artificially contaminated samples gave positive results independently of the number of cells inoculated. On the contrary, the naturally contaminated samples were all negative. The results obtained from this experiment demonstrated that this protocol could be used for monitoring the spread of these organisms in food.
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Affiliation(s)
- L Cocolin
- Dipartimento di Scienze degli Alimenti, Facoltà di Agraria, Università degli studi di Udine, Italy
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183
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Cutter CN, Rivera-Betancourt M. Interventions for the reduction of Salmonella Typhimurium DT 104 and non-O157:H7 enterohemorrhagic Escherichia coli on beef surfaces. J Food Prot 2000; 63:1326-32. [PMID: 11041130 DOI: 10.4315/0362-028x-63.10.1326] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A study was conducted to determine if slaughter interventions currently used by the meat industry are effective against Salmonella Typhimurium definitive type 104 (DT 104) and two non-O157:H7 enterohemorrhagic Escherichia coli (EHEC). Three separate experiments were conducted by inoculating prerigor beef surfaces with a bovine fecal slurry containing Salmonella Typhimurium and Salmonella Typhimurium DT 104 (experiment 1), E. coli O157:H7 and E. coli O111:H8 (experiment 2), or E. coli O157:H7 and E. coli O26:H11 (experiment 3) and spray washing with water, hot water (72 degrees C), 2% acetic acid, 2% lactic acid, or 10% trisodium phosphate (15 s, 125 +/- 5 psi, 35 +/- 2 degrees C). Remaining bacterial populations were determined immediately after treatments (day 0), after 2 days of aerobic storage at 4 degrees C, and after 7, 21, and 35 days of vacuum-packaged storage at 4 degrees C. In addition to enumeration, confirmation of pathogen serotypes was performed for all treatments on all days. Of the interventions investigated, spray treatments with trisodium phosphate were the most effective, resulting in pathogen reductions of >3 log10 CFU/cm2, followed by 2% lactic acid and 2% acetic acid (>2 log10 CFU/cm2). Results also indicated that interventions used to reduce Salmonella Typhimurium on beef surfaces were equally effective against Salmonella Typhimurium DT 104 immediately after treatment and again after long-term, refrigerated, vacuum-packaged storage. Similarly, E. coli O111:H8 and E. coli O26:H11 associated with beef surfaces were reduced by the interventions to approximately the same extent as E. coli O157:H7 immediately after treatment and again after long-term, refrigerated, vacuum-packaged storage. It was also demonstrated that phenotypic characterization may not be sufficient to identify EHECs and that the organisms should be further confirmed with antibody- or genetic-based techniques. Based on these findings, interventions used by the meat industry to reduce Salmonella spp. and E. coli O157:H7 appear to be effective against DT 104 and other EHEC.
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Affiliation(s)
- C N Cutter
- U.S. Department of Agriculture, Agricultural Research Service, Roman L. Hruska U.S. Meat Animal Research Center, Clay Center, Nebraska 68933, USA.
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184
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Ogierman MA, Paton AW, Paton JC. Up-regulation of both intimin and eae-independent adherence of shiga toxigenic Escherichia coli O157 by ler and phenotypic impact of a naturally occurring ler mutation. Infect Immun 2000; 68:5344-53. [PMID: 10948164 PMCID: PMC101798 DOI: 10.1128/iai.68.9.5344-5353.2000] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Shiga toxigenic Escherichia coli (STEC) strains are important human pathogens which are capable of causing diarrhea, hemorrhagic colitis, and the potentially fatal hemolytic-uremic syndrome (HUS). An important virulence trait of certain STEC strains, such as those belonging to serogroup O157, is the capacity to produce attaching and effacing (A/E) lesions on enterocytes, a property encoded by the locus for enterocyte effacement (LEE). LEE contains the eae gene, which encodes intimin, an outer membrane protein which mediates the intimate attachment of bacteria to the host epithelial cell surface, and eae is routinely used as a marker for LEE-positive STEC strains. However, the O157:H(-) STEC strain 95SF2 carries eae but did not produce A/E lesions on HEp-2 cells, as judged by a fluorescent actin staining assay. In this assay, 95SF2 adhered poorly to the HEp-2 cells, and those that did bind exhibited abnormal cell division. In contrast, the O157:H7 STEC strain EDL933 adhered strongly and produced typical A/E lesions. We have demonstrated that 95SF2 carries a defective LEE regulatory gene, ler, with a single base change with respect to that published for ler of EDL933, resulting in an Ile(57)-to-Thr substitution. Ler shows homology to H-NS-like regulators, which are modulators of transcription, and the mutation occurs in a domain implicated in oligomerization. 95SF2 was able to adhere and produce A/E lesions on HEp-2 cells when EDL933 ler was expressed from a multicopy plasmid. Conversely, introduction of a plasmid carrying 95SF2 ler into EDL933 abolished adherence and capacity to form A/E lesions. Studies with eae deletion derivatives of 95SF2 and EDL933 demonstrated that the ler-mediated adherence to HEp-2 cells is largely independent of intimin. We have also demonstrated that EDL933 ler, but not 95SF2 ler, increases the level of intimin in O157 STEC.
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Affiliation(s)
- M A Ogierman
- Molecular Microbiology Unit, Women's and Children's Hospital, North Adelaide, South Australia 5006, Australia
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185
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Martin AA, Woolven BL, Harris SJ, Keeley SR, Adams LD, Jureidini KF, Henning PH. Plasminogen activator inhibitor type-1 and interleukin-6 in haemolytic uraemic syndrome. J Paediatr Child Health 2000; 36:327-31. [PMID: 10940164 DOI: 10.1046/j.1440-1754.2000.00532.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE Because haemolytic uraemic syndrome (HUS) is an important cause of renal dysfunction in children, the availability of prognostic markers of disease severity could assist in identifying those at risk of developing long-term sequelae. The aim of this study was to test the hypothesis that plasma levels of plasminogen activator inhibitor type-1 (PAI-1) and interleukin-6 (IL-6) in children at the time of diagnosis of HUS would predict renal function outcome in terms of glomerular filtration rate (GFR). METHODOLOGY Fourteen children suffering from diarrhoeal HUS were studied. Plasma samples were assayed for PAI-1 and IL-6, and GFR was measured at intervals after discharge from hospital. Twelve months following their recovery from HUS, the children were allocated to one of two outcome groups depending on whether GFR was above (Good Outcome, n = 9), or below (Poor Outcome, n = 5) 80 mL/min per 1.73 m2. RESULTS Elevated concentrations of PAI-1 were found in 4 of 5 Poor Outcome and 4 of 9 Good Outcome children. At the same time, increased concentrations of IL-6 were observed in 3 of 5 Poor Outcome and 3 of 9 Good Outcome children. Renal function continued to be compromised in four Poor Outcome children 36 months after diagnosis. CONCLUSIONS Our data show that PAI-1 and IL-6 are elevated in the plasma of some children at the time of diagnosis of HUS, but that neither is a definitive prognostic marker of poor outcome 3 years later.
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Affiliation(s)
- A A Martin
- Renal Unit and Pediatric Intensive Care Unit, Women's and Children's Hospital, North Adelaide, South Australia, Australia
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186
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Acheson DW. How does Escherichia coli O157:H7 testing in meat compare with what we are seeing clinically? J Food Prot 2000; 63:819-21. [PMID: 10852579 DOI: 10.4315/0362-028x-63.6.819] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Escherichia coli O157:H7 is but one of a group of Shiga toxin-producing E. coli (STEC) that cause both intestinal disease such as bloody and nonbloody diarrhea and serious complications like hemolytic uremic syndrome (HUS). While E. coli O157: H7 is the most renowned STEC, over 200 different types of STEC have been documented in meat and animals, at least 60 of which have been linked with human disease. A number of studies have suggested that non-O157 STEC are associated with clinical disease, and non-O157 STEC are present in the food supply. Non-O157 STEC, such as O111 have caused large outbreaks and HUS in the United States and other countries. The current policy in the United States is to examine ground beef for O157:H7 only, but restricting the focus to O157 will miss other important human STEC pathogens.
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Affiliation(s)
- D W Acheson
- New England Medical Center, Boston, Massachusetts 02111, USA.
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187
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Affiliation(s)
- D Law
- Hyder Environmental, Manor Park, Howard Court, Runcorn, UK
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188
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Cornick NA, Matise I, Samuel JE, Bosworth BT, Moon HW. Edema disease as a model for systemic disease induced by Shiga toxin-producing E. coli. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2000; 473:155-61. [PMID: 10659353 DOI: 10.1007/978-1-4615-4143-1_14] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
Abstract
Edema disease (ED) is a naturally occurring disease of weaned pigs caused by host adapted strains of E. coli that produce Shiga toxin (STEC). We determined the temporal and quantitative relationships between intestinal colonization by STEC, levels of Shiga toxin (Stx2e) in the gut, in the blood, and clinical manifestations of ED. Bacterial colonization (10(8) CFU/cm ileum) was highest 4 days post inoculation (pi) in animals that did not develop clinical disease and 6 days pi in animals with clinical signs of ED. The mean time for the development of clinical signs of ED was 6 days pi (range 4-10). Average peak titers of Stx2e in the ileum were 1:16,384 in asymptomatic animals and 1:32,768 in clinical animals. Titers of Stx2e in the feces reflected the toxin titers in the ileum but were lower. Intestinal titers of Stx2e and the density of bacterial colonization were predictive of clinical ED for a group of animals but not for individuals. Approximately 50% of the pigs that had Stx2e titers of > or = 1:4096 and a bacterial density of > or = 10(6) CFU/cm in their ileum, had clinical ED. Pigs that had intestinal Stx2e titers < 1:4096 were asymptomatic. Stx2e was detected in the red cell fraction of blood from some of the pigs with clinical ED and in some that were asymptomatic. Stx2e was not detected in the serum of any animals. ED may be a useful model for predicting the temporal and quantitative relationships between bacterial colonization, Stx levels in the gut and blood and systemic disease for STEC in other species.
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Affiliation(s)
- N A Cornick
- Veterinary Medical Research Institute, Iowa State University, Ames, USA
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189
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Elder RO, Keen JE, Siragusa GR, Barkocy-Gallagher GA, Koohmaraie M, Laegreid WW. Correlation of enterohemorrhagic Escherichia coli O157 prevalence in feces, hides, and carcasses of beef cattle during processing. Proc Natl Acad Sci U S A 2000; 97:2999-3003. [PMID: 10725380 PMCID: PMC16181 DOI: 10.1073/pnas.97.7.2999] [Citation(s) in RCA: 417] [Impact Index Per Article: 17.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A survey was performed to estimate the frequency of enterohemorrhagic Escherichia coli O157:H7 or O157:nonmotile (EHEC O157) in feces and on hides within groups of fed cattle from single sources (lots) presented for slaughter at meat processing plants in the Midwestern United States, as well as frequency of carcass contamination during processing from cattle within the same lots. Of 29 lots sampled, 72% had at least one EHEC O157-positive fecal sample and 38% had positive hide samples. Overall, EHEC O157 prevalence in feces and on hides was 28% (91 of 327) and 11% (38 of 355), respectively. Carcass samples were taken at three points during processing: preevisceration, postevisceration before antimicrobial intervention, and postprocessing after carcasses entered the cooler. Of 30 lots sampled, 87% had at least one EHEC O157-positive preevisceration sample, 57% of lots were positive postevisceration, and 17% had positive postprocessing samples. Prevalence of EHEC O157 in the three postprocessing samples was 43% (148 of 341), 18% (59 of 332) and 2% (6 of 330), respectively. Reduction in carcass prevalence from preevisceration to postprocessing suggests that sanitary procedures were effective within the processing plants. Fecal and hide prevalence were significantly correlated with carcass contamination (P = 0.001), indicating a role for control of EHEC O157 in live cattle.
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Affiliation(s)
- R O Elder
- United States Meat Animal Research Center, United States Department of Agriculture, Agricultural Research Service, Clay Center, NE 68933, USA
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190
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Correlation of enterohemorrhagic Escherichia coli O157 prevalence in feces, hides, and carcasses of beef cattle during processing. Proc Natl Acad Sci U S A 2000. [PMID: 10725380 PMCID: PMC16181 DOI: 10.1073/pnas.060024897] [Citation(s) in RCA: 292] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
A survey was performed to estimate the frequency of enterohemorrhagic Escherichia coli O157:H7 or O157:nonmotile (EHEC O157) in feces and on hides within groups of fed cattle from single sources (lots) presented for slaughter at meat processing plants in the Midwestern United States, as well as frequency of carcass contamination during processing from cattle within the same lots. Of 29 lots sampled, 72% had at least one EHEC O157-positive fecal sample and 38% had positive hide samples. Overall, EHEC O157 prevalence in feces and on hides was 28% (91 of 327) and 11% (38 of 355), respectively. Carcass samples were taken at three points during processing: preevisceration, postevisceration before antimicrobial intervention, and postprocessing after carcasses entered the cooler. Of 30 lots sampled, 87% had at least one EHEC O157-positive preevisceration sample, 57% of lots were positive postevisceration, and 17% had positive postprocessing samples. Prevalence of EHEC O157 in the three postprocessing samples was 43% (148 of 341), 18% (59 of 332) and 2% (6 of 330), respectively. Reduction in carcass prevalence from preevisceration to postprocessing suggests that sanitary procedures were effective within the processing plants. Fecal and hide prevalence were significantly correlated with carcass contamination (P = 0.001), indicating a role for control of EHEC O157 in live cattle.
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191
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Paton AW, Morona R, Paton JC. A new biological agent for treatment of Shiga toxigenic Escherichia coli infections and dysentery in humans. Nat Med 2000; 6:265-70. [PMID: 10700227 DOI: 10.1038/73111] [Citation(s) in RCA: 164] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Gastrointestinal disease caused by Shiga toxin-producing bacteria (such as Escherichia coli O157:H7 and Shigella dysenteriae) is often complicated by life-threatening toxin-induced systemic sequelae, including hemolytic-uremic syndrome. Such infections can now be diagnosed very early in the course of the disease, but at present no effective therapeutic intervention is possible. Here, we constructed a recombinant bacterium that displayed a Shiga toxin receptor mimic on its surface, and it adsorbed and neutralized Shiga toxins with very high efficiency. Moreover, oral administration of the recombinant bacterium completely protected mice from challenge with an otherwise 100%-fatal dose of Shiga toxigenic E. coli. Thus, the bacterium shows great promise as a 'probiotic' treatment for Shiga toxigenic E. coli infections and dysentery.
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Affiliation(s)
- A W Paton
- Molecular Microbiology Unit, Women's and Children's Hospital, North Adelaide, S.A., 5006, Australia
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192
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Miyachi H, Yano K, Ikebukuro K, Kono M, Hoshina S, Karube I. Application of chimeric RNA–DNA oligonucleotides to the detection of pathogenic microorganisms using surface plasmon resonance. Anal Chim Acta 2000. [DOI: 10.1016/s0003-2670(99)00779-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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193
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Pointon AM, Hamilton D, Kolega V, Hathaway S. Risk assessment of organoleptic postmortem inspection procedures for pigs. Vet Rec 2000; 146:124-31. [PMID: 10706330 DOI: 10.1136/vr.146.5.124] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
A systematic quantification of foodborne hazards in abnormal and normal tissues of pig carcases was undertaken to provide a risk-based assessment of the effectiveness of traditional organoleptic meat inspection. A total of 36,059 pigs, representing all major pig-producing areas and systems in Australia, were inspected on a seasonal basis at three abattoirs over 12 months. The prevalence of grossly detectable abnormalities of possible food-borne disease significance was recorded. A subset of the grossly detectable abnormalities, together with tissues classified by inspection as normal (controls) were submitted for the detection of a broad range of food-borne hazards. The potential exposure of consumers to hazards in fresh pork was characterised as the number of carcases per 10,000 containing hazards in selected tissues. The results indicated that the level of exposure of consumers to microbiological hazards in fresh pork is unlikely to be reduced significantly by the detection and removal of gross abnormalities in the tissues examined. On the basis of carcase throughput, the rate of contamination of normal lymph nodes was commonly 100 times higher, and no hazards were isolated from two types of grossly abnormal nodes. While further processing, cooking and handling may alter the exposure characterisation, the study nevertheless identifies the proportional contribution of abnormal and normal tissues to risks to consumers and clearly identifies the need for consideration of 'visual only' inspection in the re-evaluation of traditional inspection procedures.
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Affiliation(s)
- A M Pointon
- Australian Research and Development Institute, Adelaide SA
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194
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Nicholls L, Grant TH, Robins-Browne RM. Identification of a novel genetic locus that is required for in vitro adhesion of a clinical isolate of enterohaemorrhagic Escherichia coli to epithelial cells. Mol Microbiol 2000; 35:275-88. [PMID: 10652089 DOI: 10.1046/j.1365-2958.2000.01690.x] [Citation(s) in RCA: 196] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Enterohaemorrhagic Escherichia coli (EHEC) are food-borne intestinal pathogens with a low infectious dose. Adhesion of some EHEC strains to epithelial cells is attributed, in part, to intimin, but other factors may be required for the intestinal colonizing ability of these bacteria. In order to identify additional adherence factors of EHEC, we generated transposon mutants of a clinical EHEC isolate of serotype O111:H-, which displayed high levels of adherence to cultured Chinese hamster ovary (CHO) cells. One mutant was markedly deficient in CHO cell adherence, human red blood cell agglutination and autoaggregation. Sequence analysis of the gene disrupted in this mutant revealed a 9669 bp novel chromosomal open reading frame (ORF), which was designated efa1, for EHEC factor for adherence. efa1 displayed 28% amino acid identity with the predicted product of a recently described ORF from the haemolysin-encoding plasmid of EHEC O157:H7. The amino termini of the putative products of these two genes exhibit up to 38% amino acid similarity to Clostridium difficile toxins A and B. efa1 occurred within a novel genetic locus, at least 15 kb in length, which featured a low G+C content, several insertion sequence homologues and a homologue of the Shigella flexneri enterotoxin ShET2. DNA probes prepared from different regions of efa1 hybridized with all of 116 strains of attaching-effacing E. coli (AEEC) of a variety of serotypes, including enteropathogenic E. coli (EPEC) and EHEC, but with none of 91 non-AEEC strains. Nevertheless, efa1 was not required for the attachment-effacement phenotype, and the efa1 locus was not physically linked to the locus for enterocyte effacement (LEE) pathogenicity island, which is responsible for this phenotype in EPEC. These findings suggest that efa1 encodes a novel virulence-associated determinant of AEEC, which contributes to the adhesive capacity of these bacteria.
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Affiliation(s)
- L Nicholls
- Microbiological Research Unit, Department of Microbiology and Infectious Diseases, Royal Children's Hospital, University of Melbourne, Parkville, Victoria 3052, Australia
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195
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196
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Paton AW, Woodrow MC, Doyle RM, Lanser JA, Paton JC. Molecular characterization of a Shiga toxigenic Escherichia coli O113:H21 strain lacking eae responsible for a cluster of cases of hemolytic-uremic syndrome. J Clin Microbiol 1999; 37:3357-61. [PMID: 10488206 PMCID: PMC85566 DOI: 10.1128/jcm.37.10.3357-3361.1999] [Citation(s) in RCA: 225] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/1999] [Accepted: 07/14/1999] [Indexed: 11/20/2022] Open
Abstract
Shiga toxigenic Escherichia coli (STEC) strains are a diverse group of organisms capable of causing severe gastrointestinal disease in humans. Within the STEC family, certain strains appear to have greater virulence for humans. STEC strains carrying eae and belonging to serogroup O157 or O111 have been responsible for the vast majority of outbreaks of STEC disease reported to date. Here we describe a STEC O113:H21 strain lacking eae that was responsible for a cluster of three cases of hemolytic-uremic syndrome. This strain produces a single Stx2-related toxin and adheres efficiently to Henle 407 cells.
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Affiliation(s)
- A W Paton
- Molecular Microbiology Unit, Women's and Children's Hospital, North Adelaide, S.A. 5006, Australia
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197
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Karch H, Bielaszewska M, Bitzan M, Schmidt H. Epidemiology and diagnosis of Shiga toxin-producing Escherichia coli infections. Diagn Microbiol Infect Dis 1999; 34:229-43. [PMID: 10403103 DOI: 10.1016/s0732-8893(99)00031-0] [Citation(s) in RCA: 114] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Shiga toxin-producing Escherichia coli (STEC) have been identified as a worldwide cause of serious human gastrointestinal disease and the life-threatening hemolytic uremic syndrome. The most common serotype implicated is E. coli O157: H7, but infections involving various non-O157 serotypes have been found with increasing frequency in many countries. Food-borne outbreaks caused by STEC can affect large numbers of people and cause serious morbidity, making the bacteria one of the most important emerging pathogens. Because there is no specific treatment of the disease currently available, there is an urgent need for effective preventive measures based on a detailed understanding of the epidemiology of STEC infections. Such measures will also be dependent on the availability of rapid, sensitive, and simple procedures for the detection of the pathogens both in human samples and in samples of nonhuman origin such as food. This review summarizes the current knowledge on the epidemiology of STEC infection and presents a survey of laboratory methods currently available for diagnosis of STEC. Special attention is given to new diagnostic procedures for the less readily detectable non-O157 STEC strains and to simple procedures, usually based on commercially available kits, that can be used in routine clinical microbiological laboratories.
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Affiliation(s)
- H Karch
- Institut für Hygiene und Mikrobiologie, Universität Würzburg, Germany
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198
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Rios M, Prado V, Trucksis M, Arellano C, Borie C, Alexandre M, Fica A, Levine MM. Clonal diversity of Chilean isolates of enterohemorrhagic Escherichia coli from patients with hemolytic-uremic syndrome, asymptomatic subjects, animal reservoirs, and food products. J Clin Microbiol 1999; 37:778-81. [PMID: 9986852 PMCID: PMC84553 DOI: 10.1128/jcm.37.3.778-781.1999] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
To determine clonal relationship among Chilean enterohemorrhagic Escherichia coli (EHEC) strains from different sources (clinical infections, animal reservoirs, and food), 54 EHEC isolates (44 of E. coli O157, 5 of E. coli O111, and 5 of E. coli O26) were characterized for virulence genes by colony blot hybridization and by pulsed-field gel electrophoresis (PFGE). By colony blotting, 12 different genotypes were identified among the 44 E. coli O157 isolates analyzed, of which the genetic profile stx1+ stx2+ hly+ eae+ was the most prevalent. All human O157 strains that were associated with sporadic cases of hemolytic-uremic syndrome (HUS) carried both the stx1 and stx2 toxin-encoding genes and were eaeA positive. Only 9 of 13 isolates from human controls were stx1+ stx2+, and 8 carried the eaeA gene. Comparison of profiles obtained by PFGE of XbaI-digested genomic DNA showed a great diversity among the E. coli O157 isolates, with 37 different profiles among 39 isolates analyzed. Cluster analysis of PFGE profiles showed a wide distribution of clinical isolates obtained from HUS cases and asymptomatic individuals and a clonal relationship among O157 isolates obtained from HUS cases and pigs. Analysis of virulence genes showed that a correlation exists among strains with the genotype stx1+ stx2+ eae+ and pathogenic potential. A larger difference in the PFGE restriction patterns was observed among the EHEC strains of serogroups O26 and O111. These results indicate that several different EHEC clones circulate in Chile and suggest that pigs are an important animal reservoir for human infections by EHEC. Guidelines have been proposed for better practices in the slaughter of animals in Chile.
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Affiliation(s)
- M Rios
- Programa de Microbiología y Micología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile
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199
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Goldwater PN, Giles N, Bettelheim KA. An unusual case of microangiopathic haemolytic anaemia associated with enterohaemorrhagic Escherichia coli O113:H21 infection, a verocytotoxin-2/shiga toxin-2 producing serotype. J Infect 1998; 37:302-4. [PMID: 9892539 DOI: 10.1016/s0163-4453(98)92324-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
A case of microangiopathic haemolytic anaemia and thrombocytopaenia in a 79-year-old woman is presented. The case is unusual in that diarrhoeal symptoms were brief and symptoms of anaemia caused her to re-present to hospital 6 days after the diarrhoea had ceased. Enterohaemorrhagic Escherichia coli O113:H21 producing shiga toxin-2 was isolated from a faecal specimen. This serotype has been reported only a few times to be associated with serious disease. However, it is amongst the 20 most common serotypes carried in cattle and found in beef. This case also illustrates the importance of using shiga-toxin gene detection in faecal cultures (as opposed to cultural methods for detection of the O157:H7 serotype) as the recommended investigation of human disease for accurate epidemiology and attribution of cause.
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Affiliation(s)
- P N Goldwater
- Microbiology and Infectious Diseases Department, The Women's & Children's Hospital, North Adelaide, South Australia, Australia
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200
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Paton AW, Manning PA, Woodrow MC, Paton JC. Translocated intimin receptors (Tir) of Shiga-toxigenic Escherichia coli isolates belonging to serogroups O26, O111, and O157 react with sera from patients with hemolytic-uremic syndrome and exhibit marked sequence heterogeneity. Infect Immun 1998; 66:5580-6. [PMID: 9784578 PMCID: PMC108704 DOI: 10.1128/iai.66.11.5580-5586.1998] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The capacity to form attaching and effacing (A/E) lesions on the surfaces of enterocytes is an important virulence trait of several enteric pathogens, including enteropathogenic Escherichia coli (EPEC) and Shiga-toxigenic E. coli (STEC). Formation of such lesions depends upon an interaction between a bacterial outer membrane protein (intimin) and a bacterially encoded receptor protein (Tir) which is exported from the bacterium and translocated into the host cell membrane. Intimin, Tir, and several other proteins necessary for generation of A/E lesions are encoded on a chromosomal pathogenicity island termed the locus for enterocyte effacement (LEE). Reports of sequence heterogeneity and antigenic variation in the region of intimin believed to be responsible for receptor binding raise the possibility that the receptor itself is also heterogeneous. We have examined this by cloning and sequencing tir genes from three different STEC strains belonging to serogroups O26, O111, and O157. The deduced amino acid sequences for the Tir homologues from these strains varied markedly, exhibiting only 65.4, 80.2, and 56.7% identity, respectively, to that recently reported for EPEC Tir. STEC Tir is also highly immunogenic in humans. Western blots of E. coli DH5alpha expressing the various STEC tir genes cloned in pBluescript [but not E. coli DH5alpha(pBluescript)] reacted strongly with convalescent sera from patients with hemolytic-uremic syndrome (HUS) caused by known LEE-positive STEC. Moreover, no reaction was seen when the various clone lysates were probed with serum from a patient with HUS caused by a LEE-negative STEC or with serum from a healthy individual. Covariation of exposed epitopes on both intimin and Tir may be a means whereby STEC avoid host immune responses without compromising adhesin-receptor interaction.
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Affiliation(s)
- A W Paton
- Molecular Microbiology Unit, Women's and Children's Hospital, North Adelaide, South Australia 5006.
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