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H Chart

Publications and source records attributed to H Chart.

At least 109 records · Page 6Linked to original sources
PubMed1991

The serological relationship between Yersinia enterocolitica O9 and Escherichia coli O157 using sera from patients with yersiniosis and haemolytic uraemic syndrome.

Sera from patients with yersiniosis, shown to contain antibodies to Yersinia enterocolitica O9; and sera from patients with haemolytic uraemic syndrome (HUS) caused by Escherichia coli O157, were used to investigate serological cross-reactions between Y. enterocolitica O9 and E. coli O157. Lipopolysaccharide (LPS) was isolated from strains of Y. enterocolitica O9 and E. coli O157 and reacted with sera by immunoblotting and ELISA. Sera from patients with HUS contained antibodies to the LPS of E. coli O157 only; 80% of sera from patients with yersiniosis contained antibodies to the LPS of Y. enterocolitica O9 and E. coli O157. This one-way cross-reaction was also detected using hyperimmune rabbit antisera.

Antibodies, Bacterial↗
PubMed1991

The influence of age on the response of SPF hens to infection with Salmonella enteritidis PT4.

When Specific Pathogen-Free hens were infected with Salmonella enteritidis PT4 by direct administration into the crop, the age of the bird at infection was found to have an effect on both pathogenesis and antibody response. Birds at 20 weeks of age showed no adverse signs and developed high titres of antibodies of the IgM class, while those which were 1 year old at infection developed relatively little antibody and had acute septicaemia, with 6 of 10 birds either dying or having to be humanely destroyed. The implication of these results for the control of salmonella infections in poultry is discussed.

Age Factors↗
PubMed1990

Serological response of chickens to Salmonella enteritidis infection.

Fifty-eight sera, from 29 chickens originating from two layer flocks known to be naturally infected with Salmonella enteritidis phage type (PT) 4, were examined for antibodies to S. enteritidis. Using the techniques of immunoblotting and ELISA, antibodies to the lipopolysaccharide (LPS) of S. enteritidis were detected in 43 of 58 sera. Antibodies were of the IgG class and bound to the S. enteritidis LPS antigen O = 12. Bacterial agglutination reactions using whole-cell preparations of S. enteritidis and S. pullorum, correlated with anti-LPS antibody reactions as detected by immunoblotting and ELISA. A rapid means of screening chicken sera for antibodies to the LPS of S. enteritidis as an indicator of infection is discussed.

Agglutination Tests↗
PubMed1990

Characterization of a new putative colonization factor (CS17) from a human enterotoxigenic Escherichia coli of serotype O114:H21 which produces only heat-labile enterotoxin.

Enterotoxigenic Escherichia coli (ETEC) of serotype O114:H21, which produced only heat-labile enterotoxin (LT), gave mannose-resistant hemagglutination (MRHA) with bovine erythrocytes. One strain, E20738A, was shown to possess fimbriae of approximately 7.5 nm diameter. On SDS-PAGE two possible fimbrial polypeptides of molecular masses 17.5 and 15.5 kDa were seen; the 17.5-kDa band was the most prominent. Loss of LT and MRHA together from strain E20738A was associated with loss of a 100-MDa plasmid. An absorbed anti-strain E20738A serum reacted specifically with the 17.5- and 15.5-kDa polypeptides and bound to the intact fimbriae. This antiserum reacted positively in an ELISA with LT-positive E. coli strains of serogroups O8, O15, O48, O114, and O146. The antiserum did not react with ETEC carrying known colonization factors. The term coli-surface-associated antigen (CS) 17 has been used to describe the fimbriae.

Antigens, Bacterial↗
PubMed1989

The outer membrane protein of enteropathogenic Escherichia coli, described as the 'localised adherence factor', is OmpF and probably not involved in adhesion to HEp-2 cells.

Strains of enteropathogenic Escherichia coli (EPEC) were examined for a factor, described as an outer membrane protein (OMP) of 32 kilodaltons (kDa) and reported to be involved in the adhesion of EPEC to HeLa cells. A comparable OMP of 35 kDa was detected in strains of EPEC, although expression of this protein was not related to the ability of strains to adhere to HEp-2 cells. The 35 kDa OMP was found to be heat-modifiable and peptidoglycan associated, and considered to be the porin protein OmpF.

Bacterial Adhesion↗
PubMed1989

Antigenic homology within human enterotoxigenic Escherichia coli fimbrial colonization factor antigens: CFA/I, coli-surface-associated antigens (CS)1, CS2, CS4 and CS17.

Immunoglobulins, prepared from polyclonal rabbit antisera raised against Escherichia coli fimbrial antigens, colonization factor antigen (CFA)/I, and coli-surface-associated antigens (CS)1, CS2 and CS4, were used to assess antigenic cross-reactions between these four fimbrial types by Western immunoblotting. Antibodies in a serum, prepared against CS4, cross-reacted strongly with the fimbrial subunits of CFA/I, CS1 and CS2. Antibodies in sera prepared against CFA/I and CS1 gave weak reactions with CS1 or CFA/I respectively and also with CS2 and CS4, while the antiserum prepared against CS2 did not react. CS4 antiserum also reacted with the CS17 fimbrial subunit, but not with the subunits of fimbrial antigens: CFA/III, CS5, putative colonization factor (PCF) 0159:H4 or PCF0166.

Antibodies, Bacterial↗
PubMed1989

Conversion of Salmonella enteritidis phage type 4 to phage type 7 involves loss of lipopolysaccharide with concomitant loss of virulence.

Three strains of Salmonella enteritidis phage type 4 (PT4) and 33 strains of S. enteritidis phage type 7 (PT7) were examined for the ability to produce lipopolysaccharide (LPS) and for plasmid carriage. The LPS of all strains of PT4 gave a typical 'ladder' pattern by SDS-PAGE and silver staining, and on serotyping these strains were shown to express the O-antigens 9, 12. In contrast, strains of PT7 did not express long-chain LPS and were autoagglutinable. All strains of PT4 and the majority of strains of PT7 carried a single plasmid of 38 MDa, indistinguishable when characterised by restriction endonuclease fragmentation analysis. Epidemiological and experimental observations have demonstrated a relationship between strains of S. enteritidis PT4 and PT7, and our results, using mice, show that the loss of ability of strains of PT4 to snythesise LPS is responsible for the conversion of highly virulent strains of PT4 to avirulent strains of PT7. From epidemiological data of human infections in England and Wales, we suggest that strains of S. enteritidis PT7 may be less virulent for humans.

Animals↗
PubMed1989

Virulence of Salmonella enteritidis phage type 4 is related to the possession of a 38 MDa plasmid.

Nine strains of Salmonella enteritidis phage type 4 were examined for virulence in BALB/c mice. The possession of a 38 MDa plasmid was necessary for full virulence. Strains carrying this plasmid had LD50 values of less than 20 bacteria whilst plasmid-free strains had LD50 values of greater than 10(6) bacteria when challenged intraperitoneally. Pathogenesis of disease involved the widespread distribution of bacteria throughout the tissues. Possession of the 38 MDa plasmid could not be linked with the ability of strains to express novel outer membrane proteins, to produce toxins affecting Vero, Y1, HeLa, Henle or HEp-2 cells, or to invade HEp-2 cells. Furthermore, the 38 MDa plasmid did not encode an aerobactin-mediated iron uptake system or the production of a haemolysin. Strains of S. enteritidis PT4 isolated in 1967, 1978 or 1979 and possessing the 38 MDa plasmid showed the same virulence properties as the current plasmid-carrying strains. This suggests that the enhanced virulence of the current strains for poultry is unlikely to be the result of changes in the 38 MDa plasmid.

Animals↗
PubMed1989

Production of vero cytotoxin by Escherichia coli and Shiga toxin by Shigella dysenteriae 1 as related to the growth medium and availability of iron.

Six strains of Escherichia coli producing Vero cytotoxin (VTEC) and six strains of Shigella dysenteriae 1 were examined for the production of extra- and intracellular Vero cytotoxin (VT) and Shiga toxin respectively, in relation to the growth medium and availability of iron. VTEC secreted less extracellular VT1 or VT2 when grown in trypticase soy broth (TSB) containing the iron chelator desferal, as compared to bacteria cultured in iron replete TSB. Growth in TSB containing desferal resulted in increased production of intracellular toxin by VT1 producing strains of E. coli; but had little effect on production of intracellular toxin by VT2 producing strains. Both extra- and intracellular levels of Shiga toxin were increased by growth in TSB containing desferal. Combining intra- and extracellular toxin titres, strains of E. coli producing VT1 gave highest titres following growth in TSB where iron was bound to the chelating agent desferal, while strains of S. dysenteriae 1 produced highest levels of toxin when grown in syncaseglucose broth made iron depleted using Chelex-100. Strains of S. dysenteriae 1 did not grow in syncase-glucose broth containing desferal.

Animals↗
PubMed1989

Properties of adherence factor plasmids of enteropathogenic Escherichia coli and the effect of host strain on expression of adherence to HEp-2 cells.

EPEC adherence factor (EAF) plasmids from three strains of enteropathogenic Escherichia coli (EPEC) - E2347/69 (O127:H6), E20517 (O111:H2) and E24582 (O142:H6) - were examined. The EAF plasmids were all marked with ampicillin resistance by transposition of Tn801 to give pDEP1, pDEP2 and pDEP11, respectively. All three plasmids showed incompatibility with an FIme and an FIV plasmid and had some similarity in restriction enzyme digest patterns. Plasmid pDEP1 differed from pDEP2 and pDEP11 in being autotransferring and fertility-inhibition positive. An EAF probe consisting of a 1 kb BamHI-SalI restriction endonuclease fragment of the prototype EAF-associated plasmid pMAR2 hybridized to similar-sized SalI-BamHI fragments of pDEP1 and pDEP11 but to a different-sized fragment of plasmid pDEP2. Loss of the EAF plasmids from EPEC strains resulted in a marked reduction in the ability of these strains to adhere to HEp-2 cells. The EAF-plasmid-negative variants did not express a 94 kDa outer-membrane protein (OMP). When these EAF plasmids were reintroduced into EAF-plasmid-negative EPEC strains a high level of adherence equivalent to that of the parent EPEC strains was restored and a 94 kDa OMP was usually expressed. However, when EAF plasmids were transferred into E. coli K12 or non-EPEC E. coli the host strains either did not adhere or adhered poorly to the HEp-2 cells. These transconjugants did not express a 94 kDa OMP.

Adhesins, Escherichia coli↗
PubMed1989

Characterization of a putative colonization factor (PCFO166) of enterotoxigenic Escherichia coli of serogroup O166.

Enterotoxigenic Escherichia coli (ETEC) of serogroup O166 gave mannose-resistant haemagglutination (MRHA) with bovine and human erythrocytes. The strains did not react with antisera prepared against the known colonization factors CFA/I, CFA/II, CFA/III, CFA/IV and PCFO159:H4. Strain E7476 of serotype O166:H27, which produced heat-stable enterotoxin (ST), was examined initially. It produced fimbriae about 7 nm in diameter. On SDS-PAGE two possible fimbrial polypeptides of molecular mass 15.5 and 17.0 kDa were seen. When variants of strain E7476 were isolated, loss of ST and MRHA together was associated with loss of a 98 MDa plasmid, while loss of ST alone correlated with plasmid deletion. An absorbed anti-strain E7476 antiserum reacted specifically with the 15.5 and 17.0 kDa polypeptides in Western immunoblotting and bound to the intact fimbriae by immuno-electron microscopy. When this antiserum was used in an ELISA to examine other strains of serogroup O166, a positive reaction was obtained with all the ST- and MRHA-positive strains. One strain of serotype O71:H27 and two strains of serotype O98:H- also reacted with the absorbed anti-strain E7476 antiserum. The antiserum did not react with ETEC carrying known colonization factors. E. coli K12 and a number of E. coli of different serotypes carrying a plasmid coding for ST transferred from strain E7476, all gave MRHA and reacted with the absorbed anti-strain E7476 antiserum. The term putative colonization factor O166 (PCFO166) is proposed to describe the adhesive factor(s) on ETEC of serogroup O166 because of the similarity of properties with those of known colonization factors.

Antibodies, Bacterial↗
PubMed1989

Serum antibodies to Escherichia coli serotype O157:H7 in patients with hemolytic uremic syndrome.

Sera from 13 patients with hemolytic uremic syndrome (HUS) and 8 healthy control subjects were examined for antibodies specific for bacterial antigens of Eschericia coli serotype O157:H7. Bacterial components, including outer membrane proteins (OMPs), lipopolysaccharide (LPS), and flagella, were reacted with sera by sodium dodecyl sulfate-polyacrylamide gel electrophoresis followed by immunoblotting and by enzyme-linked immunosorbent assay. All 13 serum samples from HUS patients contained high-titered antibodies of the immunoglobulin M class against O157 LPS and some OMPs. These same sera reacted weakly with some of the major OMPs, but not the LPS, of non-O157 strains of E. coli. Sera from patients did not contain antibodies to non-O157 LPS or H7 flagella. The possibility of using E. coli serotype O157 LPS in an enzyme-linked immunosorbent assay for the routine diagnostic testing of sera from HUS patients for evidence of O157:H7 infection is discussed.

Antibodies, Bacterial↗
PubMed1989

Antibodies to Escherichia coli O157 in patients with haemorrhagic colitis and haemolytic uraemic syndrome.

Twenty four sera from patients with haemolytic uraemic syndrome or haemorrhagic colitis and healthy controls were examined for antibodies to the lipopolysaccharide (LPS) of Escherichia coli O157. Faecal specimens from these patients were also examined for Vero cytotoxin producing E coli (VTEC) by DNA probes, and for faecal Vero cytotoxin. Eight patients with faecal E coli O157:H7 gave a strong antibody response to O157 LPS, shown by immunoblotting and an enzyme linked immunosorbent assay. Six symptomatic patients without evidence of faecal VTEC also gave a strong antibody response to O157 LPS. Sera from the remaining five patients and five healthy controls did not contain antibodies to E coli O157. The results suggest that the testing of sera from patients with haemorrhagic colitis or haemolytic uraemic syndrome by ELISA or immunoblot would prove valuable in addition to the established procedures for detecting VTEC, using DNA probes and testing for faecal Vero cytotoxin.

Antibodies, Bacterial↗