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H Chart

Publications and source records attributed to H Chart.

At least 55 records · Page 3Linked to original sources

Heat-stable serotyping antigens expressed by strains of Campylobacter jejuni are probably capsular and not long-chain lipopolysaccharide.

The role of lipopolysaccharide (LPS) in the serotyping of Campylobacter jejuni based on heat-stable antigens was examined using SDS-PAGE and a silver stain for carbohydrate. None of the 32 type strains of Camp. jejuni expressed long-chain LPS. Rabbit antibodies, prepared to 10 selected strains of Camp. jejuni, reacted with surface-exposed carbohydrate antigens, which were not LPS. This study suggests that the heat-stable antigens of Camp. jejuni, which form the basis for the established Penner serotyping scheme, are probably capsular and not LPS.

Animals↗

Enteroaggregative strains of Escherichia coli belonging to serotypes O126:H27 and O44:H18 express antigenically similar 18 kDa outer membrane-associated proteins.

Outer membrane-associated proteins of 18 kDa were expressed by enteroaggregative Escherichia coli (EAggEC) belonging to serotypes O126:H27 and O44:H18, which hybridized with a probe derived from a plasmid necessary for enteroaggregative adhesion. The 18 kDa proteins expressed by strains of E. coli, belonging to these serotypes, were surface exposed and antigenically similar but not structurally identical.

Antigens, Bacterial↗

Correlation of change in phage type with pulsed field profile and 16S rrn profile in Salmonella enteritidis phage types 4, 7 and 9a.

Using pulsed-field gel electrophoresis (PFGE) and 16S rRNA (rrn) analysis (ribotyping), the in vivo derivation of strains of Salmonella enteritidis PTs 9a and 7 from a strain of S. enteritidis PT 4 has been demonstrated. All strains were isolated from a single patient over a 6-week period. Further studies have demonstrated that in terms of pulsed-field profile and ribotype, the genotypes of the patient-derived strains differed from those of the reference strains of the respective phage types. It is concluded that when used in combination, these methods can provide evidence of phylogenetic relationships in apparently unrelated S. enteritidis phage types isolated during pathogenesis of disease.

Bacteriophage Typing↗

Expression of outer membrane proteins by Salmonella enteritidis relating to pH.

The pH of the environment influenced the expression of outer membrane proteins by S. enteritidis PT4 growing in broth. Growth in broth at pH 5 to 7 resulted in variation in expression of outer membrane proteins of 18 to 22 kDa. Bacteria became acid-fixed and non-viable following prolonged incubation in broth with a pH below 5, and expression of flagella was repressed.

Animals↗

Subdivision of Salmonella enteritidis PT 4 by pulsed-field gel electrophoresis: potential for epidemiological surveillance.

Using pulsed-field gel electrophoresis (PFGE), nine profile types were identified in XbaI digests of a panel of strains of Salmonella enteritidis phage type 4 (PT 4) isolated in England and Wales between 1967 and 1992. When applied to 39 isolates from humans, chickens, poultry products and feed, strains belonging to pulsed-field profile (PFP) 1 predominated. DNA-DNA hybridization studies demonstrated that a band of approximately 57 kb was associated with the presence of the 38 MDa S. enteritidis 'serovar-specific' plasmid. It is concluded that PFGE provides a method for discriminating strains of S. enteritidis PT 4 suitable for epidemiological investigations.

Animals↗

Isolation of Vero cytotoxin-producing Escherichia coli serotypes O9ab:H- and O101:H-carrying VT2 variant gene sequences from a patient with haemolytic uraemic syndrome.

Vero cytotoxin-producing Escherichia coli (VTEC) were isolated from the faecal specimen of a patient with haemolytic uraemic syndrome. The isolates belonged to two rare VTEC serotypes, O9ab:H- and O101:H-. Polymerase chain reaction gene amplification products were detected with primers specific for the VT2e gene, a variant of VT2. The toxin from both isolates was cytotoxic to Vero cells but not to HeLa cells. An 18 kb EcoRI restriction enzyme fragment of genomic DNA from both strains hybridised with a VT2 polynucleotide DNA probe.

Aged↗

Use of plasmid profile typing for surveillance of Salmonella enteritidis phage type 4 from humans, poultry and eggs.

Plasmids were found in 1022 of 1089 (94%) of drug-sensitive strains of Salmonella enteritidis phage type 4 from humans (sporadic and outbreak cases), poultry (chickens) and eggs in England and Wales in the 5-year period 1988-92 and 25 plasmid profile patterns were identified. Strains characterized by a single plasmid of 38 MDa predominated (= plasmid profile type SE 38), comprising over 90% of isolates from humans, 70% from poultry and 92% from eggs. Eleven profile types were identified in strains from humans, 21 in strains from poultry and 3 in strains from eggs. Eight of the 11 patterns identified in human isolates were found in strains from poultry and 2 in strains from eggs. In contrast 15 patterns seen in poultry were not found in strains from humans. Four percent of strains from humans and 13% from poultry did not carry the 38 MDa plasmid but all strains from eggs were found to carry this plasmid. The second most common profile type in strains isolated between 1981 and 1988 was not identified in strains isolated from 1988-92. It is concluded that plasmid profile typing is a useful method for rapid differentiation within phage type 4 of S. enteritidis but that methods which can discriminate within the predominant profile type, SE 38, are now required.

Animals↗

Prospective study of verocytotoxin-producing, enteroaggregative and diffusely adherent Escherichia coli in different diarrhoeal states.

One hundred and eighty-one stool specimens from patients with various types of diarrhoea (135 patients) or from non-diarrhoeal controls (23 acute medical patients, 23 inflammatory bowel disease in remission) were investigated using a colony-blot DNA hybridization assay for the presence of Verocytotoxin-producing (VTEC), enteroaggregative (EAggEC) and diffusely adherent (DAEC) Escherichia coli. Twelve patients had probe-positive EAggEC in the stool and 8 of these had diarrhoea, 6 following recent travel. Eight patients had DAEC, 7 of whom had travellers' diarrhoea. Six of 10 (60%) travellers with gastroenteritis, but without a recognized enteric pathogen, were positive for EAggEC (4) or DAEC (2). Five of 10 (50%) travellers with gastroenteritis related to a recognized enteric pathogen also had DAEC identified in their stool. Of the 23 acute medical control patients 11 had been abroad, 4 of these were immigrants and had EAggEC. VTEC were not found and, with one exception, immunoassays for antibodies to E. coli O 157 and O 2 lipopolysaccharides were negative.

Adult↗

Expression of a new porin 'OmpE' by strains of Salmonella enteritidis.

Strains of Salmonella enteritidis expressed a novel porin with a subunit size of 35.5 kDa as shown by SDS-PAGE. This protein was expressed as a major outer membrane protein (MOMP) when grown on nutrient agar, McConkey agar or blood agar, or in Tris-succinate medium; but was only produced in trace amounts when strains were grown in nutrient broth. This OMP was produced by all strains of S. enteritidis examined, regardless of phage type, and expression was not related to the possession of a 38-MDa mouse-virulence plasmid or the ability of strains to make long-chain lipopolysaccharide. This new porin has been tentatively called OmpE.

Bacterial Outer Membrane Proteins↗

Serological detection of verocytotoxin-producing Escherichia coli in patients with haemolytic uraemic syndrome in western Europe.

Sera from 45 patients from The Netherlands, Germany and Belgium who had a clinical diagnosis of haemolytic uraemic syndrome (HUS) were screened for antibodies to the lipopolysaccharide (LPS) of Escherichia coli producing Verocytotoxin (VTEC). Sera from 43 family contacts and 34 control patients were also examined. Using the techniques of EIA and immunoblotting, antibodies to the LPS of Escherichia coli O157 were found in 28 patients, and to the LPS of serogroups O115 and O145 in one patient and one family member respectively. The results of our study suggest that VTEC, and in particular Escherichia coli O157, might be a significant cause of HUS in Western Europe.

Antibodies, Bacterial↗