The Common Ovine Shiga Toxin 2-Containing
            <i>Escherichia coli</i>
            Serotypes and Human Isolates of the Same Serotypes Possess a Stx2d Toxin Type

Ramachandran, Vidiya; Hornitzky, M.; Bettelheim, K. A.; Walker, Mark J.; Djordjevic, Steven P.

doi:10.1128/jcm.39.5.1932-1937.2001

Cited by 67 publications

(85 citation statements)

References 35 publications

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“…STEC, including EHEC O157 and other serogroups associated with human infections like O91, O128 and O146, have been frequently isolated from the intestinal content of sheep [72,140,171]. EHEC O157 has also been found in both meat [27] and milk [146] and sheep are now considered as an important reservoir for human infection.…”

Section: Other Ruminant Speciesmentioning

confidence: 99%

Enterohaemorrhagic Escherichia coli: emerging issues on virulence and modes of transmission

et al. 2005

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-Enterohaemorrhagic Escherichia coli (EHEC) constitute a subset of serotypes (E. coli O157 and some other serogroups) of Shiga toxin (Stx)-producing E. coli (STEC) firmly associated with severe human illnesses like bloody diarrhoea and haemolytic uraemic syndrome. Stx production is essential but not sufficient for EHEC virulence. Most strains are capable of colonising the intestinal mucosa of the host with the "attaching and effacing" mechanism, genetically governed by a large pathogenicity island (PAI) defined as the Locus of Enterocyte Effacement. Other virulence factors carried by mobile genetic elements like PAI and plasmids have been recently described, and their role in the pathogenic process has not been fully elucidated. EHEC are zoonotic pathogens. They rarely cause disease in animals, and ruminants are recognised as their main natural reservoir. Cattle are considered to be the most important source of human infections with EHEC O157, and the ecology of the organism in cattle farming has been extensively studied. The organism has also been reported in sheep, goats, water buffalos, and deer. Pigs and poultry are not considered to be a source of EHEC and the sporadic reports may derive from accidental exposure to ruminant dejections. The epidemiology of EHEC infections has remarkably changed during the past ten years and an increasing number of unusual food vehicles have been associated with human infections. New routes of transmission have emerged, like contact with animals during farm visits and a wide variety of environment-related exposures. As for other zoonotic agents, having animals and raw products that are free from EHEC is not possible in practice. However, their occurrence can be minimised by applying high standards of hygiene in all the steps of the food production chain.

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Section: Other Ruminant Speciesmentioning

confidence: 99%

Enterohaemorrhagic Escherichia coli: emerging issues on virulence and modes of transmission

et al. 2005

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“…Furthermore, O113:H21 was identified in 10 of 41 (24.4%) STEC isolates recovered from a Canadian study of naturally contaminated beef (3). All of the O113:H21 isolates recovered in our study (22 Ramachandran et al (44) reported that ovine STEC isolates that also contain ehxA and/or eaeA predominantly possess stx 2d (stx 2d-Ount , stx 2d-OX3a , and stx 2dO111 ) subtypes. In contrast, the cattle STEC isolates described in this study rarely possessed stx 2d subtypes (5 of 138; 3.6%) and three of these isolates possessed STEC serotypes (O5:H Ϫ and O91:H Ϫ ) typically found in sheep.…”

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confidence: 99%

“…STEC containing stx 2vhb alone (8 of 138; 5.8%), stx 2d-Ount (2 of 138; 1.4%), or stx 2d-OX3a (3 of 138; 2.2%) was isolated infrequently (Table 4). Two bovine isolates of the serotype O5:H Ϫ , a serotype commonly recovered from ovine feces (14), possessed an stx 2d-OX3a subtype; this subtype is commonly associ- (44). Representative RFLP profiles produced by the digestion of PCR amplification products spanning different regions of stx 2 are depicted in Fig.…”

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confidence: 99%

“…For DNA sequencing, PCR amplification products were purified using a QIAquick DNA purification kit (Qiagen, Hilden, Germany). Sequencing reactions were performed using the Big Dye terminator cycle sequencing ready reaction DNA sequencing kit and electrophoresed on an ABI prism 377 DNA sequencer (Perkin Elmer, Foster City, Calif.) as described previously (44). Auto Assembler software (Perkin Elmer) was used to compile and analyze the DNA sequences.…”

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confidence: 99%

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Bovine Non-O157 Shiga Toxin 2-Containing Escherichia coli Isolates Commonly Possess stx _2-EDL933 and/or stx _2vhb Subtypes

et al. 2003

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stx 2 genes from 138 Shiga toxin-producing Escherichia coli (STEC) isolates, of which 127 were of bovine origin (58 serotypes) and 11 of human origin (one serotype; O113:H21), were subtyped. The bovine STEC isolates from Australian cattle carried ehxA and/or eaeA and predominantly possessed stx 2-EDL933 (103 of 127; 81.1%) either in combination with stx 2vhb (32 of 127; 25.2%) or on its own (52 of 127; 40.4%). Of 22 (90.9%) bovine isolates of serotype O113:H21, a serotype increasingly recovered from patients with hemolytic uremic syndrome (HUS) or hemorrhagic colitis, 20 contained both stx 2-EDL933 and stx 2vhb ; 2 isolates contained stx 2vhb only. Although 7 of 11 (63.6%) human O113:H21 isolates associated with diarrhea possessed stx 2-EDL933 , the remaining 4 isolates possessed a combination of stx 2-EDL933 and stx 2vhb . Three of the four were from separate sporadic cases of HUS, and one was from an unknown source.Shiga toxin-producing Escherichia coli (STEC) is commonly carried by ruminants (especially cattle) and is an important enteropathogen, causing human diseases ranging from mild diarrhea to more severe conditions such as hemorrhagic colitis (HC) and hemolytic uremic syndrome (HUS) (7, 15, 22a, 25, 28, 47). Although over 150 serotypes of STEC have been associated with human disease (12, 20), serotype O157:H7 is believed to be responsible for the majority of outbreaks and sporadic cases of HUS in the United States, Japan, and Europe. However, non-O157 STEC is of greater significance in Australia (16) and Argentina (35), and its role in HUS and HC in the United States and Europe is gaining recognition (24).The most critical factors of STEC associated with severe human disease are the Shiga toxins. STEC can produce one or both of these groups of toxins which comprise two immunologically non-cross-reactive groups (designated Stx1 and Stx2), although other virulence factors such as intimin and enterohemolysin either directly contribute to (or are implicated by association with) the pathogenicity of STEC (11,21). stx 2 comprises 11 distinct variants (5,19,23,31,38,39,42,45,46,50) and is considered the most important STEC virulence factor associated with human disease (11,21,34,41). More importantly, differences in the degree of pathogenicity of STEC serotypes have been associated with variations in the stx 2 subtype (27,29,30,42). The most frequently reported stx 2 subtypes are represented by stx 2c , stx 2d , and stx 2e (42,46,50).Although more than 200 different O:H serotypes of STEC have been isolated from cattle (1,7,12,20,24,49,51), there is a paucity of information regarding associations between serotype, stx 2 subtype, and virulence factor profiles among STEC isolates from meat-producing animals (9, 10, 22a, 26, 33, 43). stx 2 subtypes stx 2-EDL933 and stx 2c (stx 2vha and stx 2vhb ) have been described in European studies of bovine STEC; however, their association with serotype has not been reported previously (8,42,46). Ramachandran et al. (44) demonstrated that stx 2 -containing STEC from ovine f...

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“…In subsequent experiments we spiked these samples with DNA from HPV and were still able to obtain clean signature sequences for all three targets with no interference. In our second experiment, signature DNA segments from the ␤-galactosidase (lacZ) gene (14) representing coliforms, the lambda receptor (lamB) gene (6) representing fecal coliforms, and the Shiga toxin (stx 2 ) gene (27) representing E. coli O157:H7 were simultaneously amplified generating three amplicons lamB (306 bp), lacZ (275 bp), and stx 2 (158 bp; Fig. 3B) from the same E.coli isolate.…”

Section: Resultsmentioning

confidence: 99%

Nucleotide Sequence-Based Multitarget Identification

Vinayagamoorthy¹,

Mulatz²,

Hodkinson³

2003

J Clin Microbiol

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MULTIGEN technology (T. Vinayagamoorthy, U.S. patent 6,197,510, March 2001) is a modification of conventional sequencing technology that generates a single electropherogram consisting of short nucleotide sequences from a mixture of known DNA targets. The target sequences may be present on the same or different nucleic acid molecules. For example, when two DNA targets are sequenced, the first and second sequencing primers are annealed to their respective target sequences, and then a polymerase causes chain extension by the addition of new deoxyribose nucleotides. Since the electrophoretic separation depends on the relative molecular weights of the truncated molecules, the molecular weight of the second sequencing primer was specifically designed to be higher than the combined molecular weight of the first sequencing primer plus the molecular weight of the largest truncated molecule generated from the first target sequence. Thus, the series of truncated molecules produced by the second sequencing primer will have higher molecular weights than those produced by the first sequencing primer. Hence, the truncated molecules produced by these two sequencing primers can be effectively separated in a single lane by standard gel electrophoresis in a single electropherogram without any overlapping of the nucleotide sequences. By using sequencing primers with progressively higher molecular weights, multiple short DNA sequences from a variety of targets can be determined simultaneously. We describe here the basic concept of MULTIGEN technology and three applications: detection of sexually transmitted pathogens (Neisseria gonorrhoeae, Chlamydia trachomatis, and Ureaplasma urealyticum), detection of contaminants in meat samples (coliforms, fecal coliforms, and Escherichia coli O157:H7), and detection of single-nucleotide polymorphisms in the human N-acetyltransferase ( DNA-based technologies such as the use of PCR and DNA probes (16, 17) have led to a wide range of genomic identification methods (1,2,3,8,12,13,20,21,32,38,40). However, the ultimate method for identifying a DNA target and, hence, a specific organism is considered to be the determination of a signature nucleotide sequence. The conventional chain dideoxynucleotide termination sequencing method (28) is considered the "gold standard" for determining nucleotide sequences, but it can process only one target at a time. This processing inefficiency of conventional sequencing increases the cost of screening for multiple pathogens and has therefore limited the use of this approach in routine diagnostic testing. Although attempts have been made to sequence multiple targets simultaneously (4,5,7,15,24,35), none could produce an electropherogram consisting of distinct nucleotide sequences from multiple targets. MULTIGEN (34) overcomes this problem, and we describe here its basic concepts and present three examples of applications for routine diagnostic testing. Figure 1A presents a schematic view of MULTIGEN technology, showing the determination of DNA sequences from three g...

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The Common Ovine Shiga Toxin 2-Containing Escherichia coli Serotypes and Human Isolates of the Same Serotypes Possess a Stx2d Toxin Type

Cited by 67 publications

References 35 publications

Enterohaemorrhagic Escherichia coli: emerging issues on virulence and modes of transmission

Enterohaemorrhagic Escherichia coli: emerging issues on virulence and modes of transmission

Bovine Non-O157 Shiga Toxin 2-Containing Escherichia coli Isolates Commonly Possess stx _2-EDL933 and/or stx _2vhb Subtypes

Nucleotide Sequence-Based Multitarget Identification

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The Common Ovine Shiga Toxin 2-Containing Escherichia coli Serotypes and Human Isolates of the Same Serotypes Possess a Stx2d Toxin Type

Cited by 67 publications

References 35 publications

Enterohaemorrhagic Escherichia coli: emerging issues on virulence and modes of transmission

Enterohaemorrhagic Escherichia coli: emerging issues on virulence and modes of transmission

Bovine Non-O157 Shiga Toxin 2-Containing Escherichia coli Isolates Commonly Possess stx 2-EDL933 and/or stx 2vhb Subtypes

Nucleotide Sequence-Based Multitarget Identification

Contact Info

Product

Resources

About

Bovine Non-O157 Shiga Toxin 2-Containing Escherichia coli Isolates Commonly Possess stx _2-EDL933 and/or stx _2vhb Subtypes