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H Chart

Publications and source records attributed to H Chart.

At least 91 records · Page 5Linked to original sources

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↗

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↗

Structure and antigenic properties of Citrobacter freundii lipopolysaccharides.

Citrobacter freundii strain E69366 was detected in a colony immunoassay with a rabbit antiserum prepared to a strain of Escherichia coli belonging to serogroup O157. Lipopolysaccharide (LPS) was shown to contain the epitope(s) involved in antibody binding. LPS prepared from strain E69366, with hot phenol contained core-LPS that migrated to the water-phase and long-chain LPS that separated into the phenol-phase. A total of 36 strains of Cit. freundii were analysed for their LPS profiles by SDS-PAGE. Sixteen could be allocated into five groups (A(3), B(7), C(2), D(2) and E(2)) based on similarities in LPS profile. The remaining strains either expressed unique SDS-PAGE profiles (18) or did not express long-chain LPS (2). All strains with a profile 'A' reacted with the antiserum prepared to E. coli O157, whereas those with other profiles did not. The two strains of Cit. freundii expressing LPS profiles designated 'E' reacted with an antiserum prepared in rabbits to E. coli O45.

Adult↗

Vero cytotoxin-producing Escherichia coli O 157 in the United Kingdom.

A total of 226 cultures of Vero cytotoxin-producing Escherichia coli O 157 isolated from humans was received by the PHLS Laboratory of Enteric Pathogens during the six month period January to June 1992. A record monthly total of 122 isolates was received in June. Ten phage types (PT) were identified during this period; PT 2 (45%) and PT 49 (21%) predominated. In addition, 27 human sera with antibodies to E. coli O 157 lipopolysaccharide (LPS) were examined from other cases during this period, making a total of 253 cases of infection associated with E. coli O 157.

Bacterial Toxins↗

Airborne infection of laying hens with Salmonella enteritidis phage type 4.

Hens were exposed to small-particle aerosols containing different concentrations of Salmonella enteritidis phage type 4. They developed a systemic infection and some birds were still excreting the organism in the faeces when killed 28 days after infection. S enteritidis was present for a similar period in a wide range of alimentary tract issues and in the ovary and oviduct.

Aerosols↗

Serological diagnosis of infection by Shigella dysenteriae-1 in patients with bacillary dysentery.

A total of 192 samples of serum from 113 Sri Lankan patients with clinical dysentery was examined for antibodies of the IgM class to the lipopolysaccharides (LPSs) of Shigella dysenteriae-1 and Escherichia coli O157:H7. By means of ELISA and immunoblotting, 59 patients were found to have serum antibodies to the LPS of S. dysenteriae-1 only. Four samples from one patient were found to contain serum antibodies to the LPSs of both S. dysenteriae-1 and E. coli O157:H7. Antibodies to the LPS of S. dysenteriae-1 were also detected in 16 samples from 25 children, from Sri Lanka, with no previous history of dysentery; one of these children also had antibodies to the LPS of E. coli O157:H7. Analysis of 16 samples from apparently healthy children in the U.K. showed that only one serum contained antibodies to the LPS of S. dysenteriae-1. This patient had a history of recent travel to Pakistan. The isolation of S. dysenteriae-1 remains the preferred test for the diagnosis of bacillary dysentery. The use of serology as a means of providing evidence of infection with S. dysenteriae-1, however may prove to be a useful adjunct to cultural techniques but needs to be validated in an area where this organism is endemic.

Child, Preschool↗

Improved detection of infection by Escherichia coli O157 in patients with haemolytic uraemic syndrome by means of IgA antibodies to lipopolysaccharide.

Samples of serum from 125 patients with haemolytic uraemic syndrome, were screened for antibodies of the IgA and IgM classes to the lipopolysaccharide (LPS) of Escherichia coli O157:H7. By means of the techniques of ELISA and immunoblotting, 48 samples were shown to contain antibodies of the IgM class to E. coli O157 LPS, while 42 samples contained IgA antibodies to this O-antigen. Thirteen patients produced IgM but not IgA antibodies to the LPS of E. coli O157:H7. Of 42 patients with IgA antibodies to the E. coli O157 LPS, seven did not produce antibodies of the IgM class. From this study, screening patients' serum for antibodies to E. coli O157 LPS of the IgA class, in addition to those of the IgM class, a total of 55 patients were shown to be seropositive. This constituted an increase is in the sensitivity of obtaining evidence of infection by this organism by 12%.

Antibodies, Bacterial↗

The serological relationship between Escherichia coli O157 and Yersinia enterocolitica O9 using sera from patients with brucellosis.

Sera from ten patients with positive brucella serology were used to investigate antibody cross-reactions between the O-antigens of Escherichia coli O157 and Yersinia enterocolitica O9. SDS-PAGE profiles of lipopolysaccharide (LPS), purified from strains of E. coli O157 and Y. enterocolitica O9, were reacted with sera by immunoblotting. All ten sera contained antibodies which bound to the LPS of E. coli O157, and five of these sera also contained antibodies which bound to the LPS of Y. enterocolitica O9. Absorption studies using these five cross-reacting sera indicated the existence of at least three epitopes exposed on the O-antigens of E. coli O157 and Y. enterocolitica O9. One antigen binding site appeared to be exposed on the LPS of both organisms, while one epitope was exposed on the LPS of E. coli O157 only, and another on the LPS of Y. enterocolitica O9 only.

Absorption↗

Serological responses of chickens experimentally infected with Salmonella enteritidis PT4 by different routes.

Commercially reared chickens were challenged with Salmonella enteritidis phage-type (PT) 4 by aerosol, or via the conjunctiva. Inhalation of 2.9 x 10(2) or 4.2 x 10(3) S. enteritidis resulted in the production of IgG antibodies to the lipopolysaccharide (LPS) of S. enteritidis PT4. When the aerosol inoculum was increased to 2.4 x 10(5) bacteria per bird the antibody produced were predominantly of the IgM-class. Chickens challenged with 10(3) S. enteritidis PT4 via the conjunctiva mounted only a poor immune response. Increasing the challenge dose to 10(8) S. enteritidis resulted in the production of high-titre serum antibodies of both the IgG and IgM classes. Results from this study suggest that aerosols containing small numbers of S. enteritidis PT4 might be responsible for intraflock infection of poultry.

Animals↗

Antibodies to lipopolysaccharide and outer membrane proteins of Salmonella enteritidis PT4 are not involved in protection from experimental infection.

BALB/c and Schofield mice were inoculated with formalin-killed bacteria prepared from strains of Salmonella enteritidis belonging to phage type (PT) 4 and carrying a 38 MDa plasmid and expressing long-chain lipopolysaccharide, or strains without a 38 MDa plasmid or lacking the ability to express lipopolysaccharide. Vaccinated mice were challenged with viable bacteria belonging to a virulent strain of S. enteritidis (PT4). Mice surviving this viable challenge were examined for a humoral antibody response to membrane antigens of S. enteritidis (PT4) that might relate to the possession of a given virulence property. BALB/c mice immunized with any of the test antigens were found to be immune to S. enteritidis (PT4), and this immunity was protective. Serum antibodies, of the IgG class, were detected to OmpA and a minor outer membrane protein (OMP) of 31 kDa. Schofield mice also raised IgG antibodies to these outer membrane proteins; however, non-immunized mice of this strain were resistant to infection. The virulence of S. enteritidis (PT4) was also tested using mice belonging to strains B10D2 (new), Biozzi (high), Biozzi (low), C3HeJ, B10ITYR and C57/L.

Animals↗

Salmonella enteritidis PT4 infection in specific pathogen free hens: influence of infecting dose.

The period during which specific pathogen free hens, infected by direct introduction into the crop of either 10(3), 10(6) or 10(8) cells of Salmonella enteritidis PT4, excreted the organism in faeces was closely related to the size of the inoculum, with the birds excreting for mean periods of 3.4, 16.4 and 36.8 days, respectively. The production of either IgG or IgM was also dose related with the birds which received 10(3) cells having lower antibody levels than those in the other two groups. In contrast, there was no relationship between the contamination of egg contents and either antibody status, faecal excretion, or the dose administered.

Animals↗

Serological identification of Escherichia coli O157:H7 infection in haemolytic uraemic syndrome.

To test the value of serological tests as an adjunct to bacteriological methods and toxin testing in haemolytic uraemic syndrome (HUS), 60 patients with the disorder were examined for evidence of faecal Escherichia coli producing verocytotoxin (VTEC), particularly of serogroup O157. They were also tested for serum antibodies reacting with the lipopolysaccharide of E coli O157 by means of an enzyme-linked immunosorbent assay (ELISA) and immunoblotting; for faecal VTEC by means of DNA probes hybridising with the genes encoding verocytotoxins VT1 and VT2; and for "free" faecal VT. Strains of E coli serotype O157:H7 were isolated from 9 patients, and faecal VT2 was detected in 3 of them. Strains of E coli of serotypes 05:H-, O55:H10, O105ac:H18, and O163:H19 were isolated from 4 patients, but faecal VT was not detected. Faecal VT2 was present in 1 patient from whom VTEC were not isolated. Antibodies to the lipopolysaccharide of E coli O157 were detected in serum samples from 44 patients. The 9 patients with faecal O157:H7 all had high titres of these antibodies, but serum samples from 16 healthy control children were negative. Serological testing of patients with HUS for antibodies to the lipopolysaccharide of E coli O157 provides evidence of infection with E coli O157 when faecal bacteria or VT cannot be detected.

Antibodies, Bacterial↗

Purification of lipopolysaccharide from strains of Yersinia enterocolitica belonging to serogroups 03 and 09.

Lipopolysaccharide (LPS) was purified from strains of Yersinia enterocolitica belonging to serogroups 03 and 09, by three methods, and analysed by SDS-PAGE and silver staining for carbohydrate. SDS-PAGE of LPS prepared from whole-cells by digestion with proteinase-K, produced profiles containing high molecular mass LPS and a lower molecular mass region migrating as discrete bands. LPS prepared from strains belonging to serogroup 03, using a hot-phenol procedure alone was found to contain cellular proteins, and LPS prepared from strains of serogroup 09, by this method, did not contain high molecular mass carbohydrate. A novel method of preparing LPS by digesting bacterial outer membranes with proteinase-K prior to hot-phenol extraction produced protein-free LPS from strain of Y. enterocolitica 03 and high molecular mass LPS from strains belonging to serogroup 09.

Cell Membrane↗