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B Rowe

Publications and source records attributed to B Rowe.

At least 127 records · Page 7Linked to original sources
PubMed1993

Phage typing of Vero cytotoxin-producing Escherichia coli O 157 isolated in the United Kingdom: 1989-91.

Between 1989 and 1991 a total of 1092 Vero cytotoxin-producing Escherichia coli O 157 isolated in the United Kingdom were phage typed in the Laboratory of Enteric Pathogens (LEP). Twenty-three phage types was identified, the most frequent being types 2 (36.1%), 49 (29.6%), 1 (10.3%) and 4 (8.9%). Although isolations of O 157 VTEC have increased each year from 1 in 1982 to 532 in 1991, the predominant phage types have remained unchanged although the proportion of strains belonging to types 2 and 49 has increased. O 157 VTEC from 17 outbreaks were phage typed during this period with phage type 49 predominating (7 of 17 outbreaks).

Bacterial Toxins↗
PubMed1993

Vero cytotoxin-producing Escherichia coli, particularly serogroup O 157, associated with human infections in the United Kingdom: 1989-91.

This survey reports the results of investigations performed by the Laboratory of Enteric Pathogens (LEP), to identify evidence of human infection with Vero cytotoxin-producing Escherichia coli (VTEC) in the UK during the period 1989-91. Bacterial isolates, faecal specimens and serum samples were received from patients suffering from diarrhoea, bloody diarrhoea and haemolytic uraemic syndrome. Using serotyping, Vero cytotoxin gene probing and an ELISA for serum antibodies to E. coli O 157, evidence of infection was detected in 232, 428 and 615 individuals in 1989, 1990 and 1991 respectively. Of these individuals, 15% were reported as having HUS. Vero cytotoxin-producing E. coli O 157 was the most frequently encountered serogroup, with isolations from a total of 1092 individuals over the 3-year period. The incidence of VTEC infection increased from 0.41/100,000 in 1989 to 1.07/100,000 in 1991. The area with the highest rate of infection in each year was Scotland, increasing from 1.37/100,000 in 1989 to 3.97/100,000 in 1991.

Adolescent↗
PubMed1993

Verotoxin producing Escherichia coli O 157 infections associated with the consumption of yoghurt.

Sixteen cases of verotoxin producing Escherichia coli (VTEC) O 157:H7 Phage Type 49 infection were identified in the North West of England from 1 September to 1 November 1991, eight of whom lived in or around the same large town. Eleven of the cases were aged 10 years or less, and five of the affected children developed haemolytic uraemic syndrome. A case control study demonstrated a strong association between VTEC O 157:H7 PT 49 infection and the consumption of a locally produced live yoghurt. This is the first time that an outbreak of VTEC O 157 infection has been linked to the consumption of yoghurt and this vehicle of infection should be considered when investigating such outbreaks in future.

Adolescent↗
PubMed1993

A comparison of multiple drug resistance in salmonellas from humans and food animals in England and Wales, 1981 and 1990.

For Salmonella typhimurium from humans in England and Wales, the incidence of multiple resistance more than doubled over the 8-year period 1981-8 and, over the next 2 years, increased by a further 7%. From 1981 to 1988 both resistance and multiple resistance also increased significantly in S. virchow and although multiple resistance did not increase over the next 2 years, the overall incidence of resistance has continued to rise. In 1990 the majority of S. typhimurium from cattle were multiply-resistant and the occurrence of such resistance has quadrupled since 1981. Multiple resistance has also increased in S. typhimurium from pigs and, to a lesser extent, from poultry. In contrast, multiple resistance has remained uncommon in the poultry-associated serotype S. enteritidis. For S. virchow, multiple resistance was common in a phage type frequently associated with poultry meat imported from France. The continuing use of a range of different antimicrobials in calf husbandry has been an important factor in promoting the emergence of multiply-resistant strains of S. typhimurium in cattle. In contrast, multiple resistance has remained rare in those serotypes associated with poultry, where the use of such antimicrobials has been less intensive. It is hoped that recent recommendations discouraging, in veterinary medicine, the prophylactic use of antibiotics with cross resistance to those used in human medicine will result in a reduction in the occurrence of multiresistant strains in food animals and subsequently in humans.

Animals↗
PubMed1993

Virulence properties of Escherichia coli strains belonging to serogroups O26, O55, O111 and O128 isolated in the United Kingdom in 1991 from patients with diarrhoea.

Some strains of Escherichia coli belonging to serogroups O26, O55, O111 or O128 produce Vero cytotoxin (VT). These serogroups are included in the range of enteropathogenic E. coli (EPEC) serogroups for which commercial antisera are available. In an attempt to obtain information on VT-producing strains other than those of serogroup O157, 122 strains belonging to these four serogroups and isolated in 1991 from patients with diarrhoea in the United Kingdom were tested for hybridization with VT probes. Only 18 of the 122 strains were VT-positive and these were O26 or O128. However 90 strains hybridized with the E. coli attaching and effacing (eae) probe (including 14 VT-positive strains) and 17 with the enteroaggregative E. coli (EAggEC) probe. For 78 eae-positive and 9 EAggEC-positive strains, tissue culture tests correlated with the probe results as the strains gave, respectively, either localized adhesion and a positive fluorescent-actin staining test or a characteristic aggregative attachment. A total of 111 of the 122 strains belonging to serogroups O26, O55, O111 or O128 possessed properties that may be associated with the ability to cause human diarrhoeal disease, and similar studies are needed on strains from the other classical EPEC serogroups.

Adult↗
PubMed1993

Outer membrane characteristics of Salmonella enteritidis phage type 4 growing in chickens.

Strains of Salmonella enteritidis belonging to phage type 4 (SE4) were grown in the peritoneal cavities of chickens, and without subculture on laboratory media examined for inducible in vivo phenotypic characteristics. These bacteria expressed three major outer membrane proteins (OMPs) of 33, 35 and 36 kilodaltons (kDa), and iron regulated OMPs of 74, 78 and 81 kDa. Bacteria growing in vivo did not express flagella, or fimbriae with a subunit molecular mass of 14 kDa (14 kDa fimbriae). Two OMPs of 55 and 23 kDa, expressed during culture in nutrient broth, were repressed during growth in chickens. Possession of a 38 MDa 'mouse virulence' plasmid did not influence the expression of OMPs, flagella or fimbriae. It was concluded that strains of SE4 growing in chicken tissues, use an enterobactin mediated iron uptake system to obtain ferric ions, do not express flagella or 14 kDa fimbriae and appear not to express novel OMPs involved in survival in vivo.

Animals↗
PubMed1993

The problems of tracing a geographically widespread outbreak of salmonellosis from a commonly eaten food: Salmonella typhimurium DT193 in north west England and north Wales in 1991.

Geographically widespread outbreaks involving commonly isolated organisms and where the vehicles of infection are commonly eaten foodstuffs pose particular difficulties at a technical and organizational level. An outbreak of Salmonella typhimurium infection, affecting 39 people, spread over a wide area in North West England and North Wales in April and May 1991, was detected thanks to the practice of sending specimens to the national reference laboratory where phage typing and characterizing of antibiotic resistance patterns enabled the identification of a cluster of distinctive isolates (S. typhimurium DT193 resistant to sulphonamides, trimethoprim and furazolidone). An investigation, involving twenty environmental health departments in addition to health authorities and the Public Health Laboratory Service, showed an association between the illness and eating loose sliced cooked ham (P = 0.004). Detailed tracing of the chain of supply of the ham showed this to be particularly cooked ham originating from a single small local producer (P = 0.00003). Further investigation of that producer revealed that a batch of ham distributed on one day in early April was undercooked due to a malfunction in cooking equipment.

Adolescent↗
PubMed1993

Molecular characterization of plasmids in Salmonella enteritidis phage types.

Plasmids in selected type strains of 26 of the Salmonella enteritidis phage types have been characterized by restriction enzyme fingerprinting and by DNA-DNA hybridization with oligonucleotide probes for Salmonella plasmid virulence (Spv) genes. With one exception, the fingerprints of the 38 MDa plasmids studied were homogeneous but there was heterogeneity in the fingerprints of 59 MDa plasmids found in 4 of the type strains. However all 38 MDa and 59 MDa plasmids were related as was a 45 MDa plasmid identified in the type strain of phage type 19. A 3.5 kb fragment homologous to SpvC was conserved in Hind III digests of all 38 MDa and 59 MDa plasmids, and in the related 45 MDa plasmid. In contrast a 65 MDa plasmid found in the type strain of phage type 10 was not related to these three plasmid molecular weight groups and did not carry the SpvC gene.

Base Sequence↗
PubMed1993

Genotype analysis of faecal and blood isolates of Salmonella dublin from humans in England and Wales.

An analysis of genotype was made for representative strains of Salmonella dublin. The collection consisted primarily of strains isolated from humans in England and Wales, and were of both intestinal and extra-intestinal origin. Three genetic elements were characterized by DNA hybridization. They were the spvBC genes, extrachromosomal virulence determinants, the salmonella-specific insertion sequence IS200, and the 16S ribosomal RNA genes, a phylogenetic marker. Two clones of S. dublin (SdRI and SdRII) which shared an identical IS200 profile, were identified on the basis of restriction fragment length polymorphism at the 16S rRNA locus. With one exception, all strains harboured a 52 MDa plasmid which contained a conserved 3.7 kbp Hind III fragment homologous to the spvBC mouse-virulence genes of S. typhimurium. However, a single plasmid-free strain of SdRI, isolated from a patient with septicaemia exhibited no spc homology. In SdRI there was no observable genotype distinction between strains causing gastroenteritis or bacteraemia. In contrast, none of the strains of SdRII were from cases of bacteraemia, and all human isolates of this clone were from cases of gastroenteritis.

Bacteremia↗
PubMed1993

A large outbreak of human salmonellosis traced to a local pig farm.

An outbreak of Salmonella typhimurium definitive type (DT) 193 affecting 206 persons occurred in July and August 1989 in a small town in northern England. A descriptive study suggested that cold meats including pork from a butcher's shop in the town were vehicles of infection. An analytical study of a cohort attending a function in the town showed a significant association between illness and consumption of cold roast pork supplied by the butcher's shop (P = 0.00000004). S. typhimurium DT 193 with the same antibiotic resistance pattern (to ampicillin, streptomycin, sulphonamides and tetracyclines) as the outbreak strain, and possessing a single plasmid of 80 MDa was isolated from samples of meat bought from the shop and implicated in illness, and from samples of pig faeces taken from the farm supplying the shop. It was concluded that inadequate processing of infected pork meat at the shop may have contributed to this outbreak but that cross contamination also played an important part in transmission. Control measures included a temporary closure of the shop and subsequent implementation of a detailed protocol for meat processing and monitoring of all procedures at the shop.

Adolescent↗
PubMed1993

Insertion sequence IS200 can differentiate drug-resistant and drug-sensitive Salmonella typhi of Vi-phage types E1 and M1.

The type strains of Vi-phage types E1, M1 and A of Salmonella typhi, together with drug-resistant and drug-sensitive strains of phage types E1 and M1 isolated in 1992 from patients associated with India or Pakistan, and a drug-resistant strain of phage type A isolated in South Africa in 1991, were characterised with respect to the presence of plasmids conferring resistance to antimicrobial drugs and their chromosomal insertion sequence IS200 profiles. The three type strains, the drug-sensitive strains of Vi-phage types E1 and M1, and a strain of phage type M1 resistant to ampicillin and trimethoprim but not to chloramphenicol, did not contain plasmids. In contrast, for strains of phage types E1 and M1 resistant to chloramphenicol, ampicillin and trimethoprim, and for the drug-resistant strain of phage type A, the complete spectrum of resistance was encoded by high molecular mass plasmids belonging to the H1 incompatibility group. Characterisation of IS200 profiles demonstrated that at least 13 IS200 copies were distributed on the chromosome of all strains tested. Although the IS200 profiles of the type strains of Vi-phage types A, E1 and M1 were identical, it was possible to distinguish between drug-sensitive and drug-resistant strains of Vi-phage types E1 and M1 isolated from patients infected in India and Pakistan by this method. It was concluded that although IS200 typing is not as discriminatory as phage typing for the primary subdivision of S. typhi, it may be useful for certain epidemiological investigations and, in particular, for investigating the origins of strains with multiple drug resistance.

Bacteriophage Typing↗
PubMed1993

Examination of raw beef products for the presence of Vero cytotoxin producing Escherichia coli, particularly those of serogroup O157.

Fifty-four of 310 (17%) samples of raw beef products contained Vero cytotoxin (VT)-producing Escherichia coli (VTEC) detected by DNA probes for the VT genes. VTEC strains examined in detail from a selection of the positive samples belonged to several O serogroups, some of which have been associated with human diarrhoea or haemolytic uraemic syndrome. Some of the strains possessed properties that may contribute to virulence in man. None of the food samples contained VT-producing E. coli O157 when tested by a combination of VT probe tests and colony immunoblotting with commercially available anti-O157 serum. Quantification of the immunoblotting technique indicated that O157 VTEC could be recovered from artificially-inoculated meat samples at a level of less than one organism per gram. Five of the food samples carried E. coli O157 strains that did not produce VT and differed in other properties from O157 VTEC.

Animals↗
PubMed1993

Characterization of Salmonella virchow phage types by plasmid profile and IS200 distribution.

The type strains of the 57 phage types of Salmonella virchow have been characterized by plasmid profile and by distribution of the insertion sequence IS200. Thirty-two strains carried plasmids and 21 profile types were identified; 17 strains were resistant to antimicrobial agents. In contrast only six of the type strains carried IS200 elements and three patterns were identified. Within Salm. virchow phage type 31, five of 10 wild-type isolates carried plasmids and two plasmid profiles were identified; in contrast, an IS200 element was identified in the genome of only one of these strains. It is concluded that for Salm. virchow, IS200 is unlikely to significantly extend the degree of discrimination achieved by phage typing which may be supplemented when appropriate by plasmid profile typing.

Animals↗
PubMed1993

Interrelationships between strains of Salmonella enteritidis belonging to phage types 4, 7, 7a, 8, 13, 13a, 23, 24 and 30.

Salmonella enteritidis strain P278849 expressed long-chain lipopolysaccharide (LPS, termed 'smooth'), carried plasmids of 38, 34 (pDEP 44, incompatibility group N, R-type AS), 2.0 and 1 MDa, and belonged to phage type (PT) 23. Introduction of pDEP 44 into a smooth strain of Salm. enteritidis PT 4 produced a smooth strain of Salm. enteritidis of PT 24. Transfer of this plasmid into a strain of PT 8 also resulted in formation of a smooth strain of Salm. enteritidis of PT 24. Moving pDEP 44 into strains of Salm. enteritidis of PTs 7 or 7a which did not express LPS (termed 'rough') resulted in rough strains of PT 23. In contrast, transfer of this plasmid into a smooth strain of Salm. enteritidis PT 7a resulted in a smooth strain of PT 23. Introduction of pDEP 44 into strains of Salm. enteritidis of PT 13 or PT 13a did not change the phage type, whereas transferring the plasmid into strains of PT 30 caused strains to become resistant to lysis by the typing phages and therefore untypable. The possibility of strains of Salm. enteritidis of PT 8 being the progenitors of strains of Salm. enteritidis of PT 24 must now be considered when investigating the epidemiology of Salm. enteritidis of PT 24 infections in areas where Salm. enteritidis PT 8 is common.

Animals↗
PubMed1993

Use of digoxigenin-labelled oligonucleotide DNA probes for VT2 and VT2 human variant genes to differentiate Vero cytotoxin-producing Escherichia coli strains of serogroup O157.

Digoxigenin-labelled oligonucleotide DNA probes specific for B-subunit genes of Vero cytotoxin 2 (VT2) and a variant of VT2 (VT2vha) were used to differentiate 116 strains of Escherichia coli serogroup O157 belonging to phage types 1, 2, 4, 8, 14, and 49. Of these strains, 38% had sequences for both VT2 and VT2vha, 38% had sequences for VT2 only, and 24% had sequences for VT2vha only. Oligonucleotide probe hybridization subdivided strains of all of the phage types except phage type 1. The greatest variation in toxin gene pattern was observed with strains of phage type 14, for which there were six distinct patterns when the presence or absence of VT1 genes was also considered. Two strains from each phage type group were examined for bacteriophages encoding VT production. Two of the six VT2vha-producing strains carried phage from which DNA hybridized with the VT2vha-specific probe. Phages were not detected in the remaining four VT2vha strains, suggesting that genes may be chromosomally located or associated with a defective prophage. In contrast, seven of the eight VT2 strains carried phages from which DNA hybridized with the VT2-specific probe. Two strains of E32511 (O157:H-) were also investigated. One strain (E32511A) possessed gene sequences for both VT2 and VTvha and was shown to carry phage possessing gene sequences for VT2. With strain E32511B, however, phages were not detected and DNA hybridized only with the VT2vha probe. Analysis of total genomic DNA digested with restriction endonuclease EcoRI showed that polymorphisms were seen with VT2 strains and not with VT2vha strains.

Bacterial Toxins↗
PubMed1993

Concentrations of interleukin 6 and tumour necrosis factor in serum and stools of children with Shigella dysenteriae 1 infection.

Serum interleukin 6 (IL-6) and tumour necrosis factor (TNF) were measured in children with dysentery during an epidemic caused by Shigella dysenteriae 1. IL-6 and TNF were also measured in fresh stool filtrates from children with acute gastroenteritis. The median serum IL-6 concentration was raised significantly in the children with complications (haemolytic uraemic syndrome, leukemoid reaction, thrombocytopenia, thrombocytosis, and severe colitis lasting more than one week) during the first week (n = 18, 9-7728 pg/ml; median 107) and in the second week (n = 13, 5-312 pg/ml; median 77), compared with convalescent sera (n = 10, < 3-85 pg/ml; median 39; p < 0.02 and < 0.05 respectively). The median IL-6 concentration during the first week was significantly higher in the group with complicated disease than in those with no complications (n = 8, < 3-37 pg/ml; median 5; p < 0.001). Although serum TNF concentrations were significantly raised in the complicated group during the first and second weeks of the illness and in the uncomplicated group compared with convalescence, there was no significant difference in the TNF concentrations between the complicated and uncomplicated groups. IL-6 was detectable in stool filtrates from eight of 13 children with S dysenteriae 1 infection and four of eight children with S flexneri infection. It was not detectable in Cryptosporidia, rotavirus, or adenovirus infections, those with pathogen-negative acute diarrhoea or controls. Seven of 13 children with S dysenteriae 1 and three of nine children with S flexneri infections had TNF detectable in stools. None of the children with Salmonella, Cryptosporidia, rotavirus of children with pathogen-negative diarrhoea and controls had detectable TNF in stool filtrates. It is postulated that the local and generalised vasculitis observed in shigellosis may be related to a direct effect of Shiga toxin on endothelial cells or caused by cytokine production stimulated by endotoxin, or both.

Child↗
PubMed1993

Patients with haemolytic uraemic syndrome caused by Escherichia coli O157: absence of antibodies to Vero cytotoxin 1 (VT1) or VT2.

Serum samples from 30 patients with haemolytic uraemic syndrome (HUS), caused by Escherichia coli O157, and 30 apparently healthy volunteers, were used to examine the immune response of patients to Vero cytotoxins (VT) 1 and VT2. Patients' sera could not be differentiated from control sera using ELISA; and using immunoblotting, none of the sera had antibodies reactive with either the A or B subunits of VT1 or VT2. Examination of sera for antibodies to VT1 and VT2 seems to be of little value in the serodiagnosis of HUS caused by Vero cytotoxin-producing E coli O157.

Antibodies, Bacterial↗