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Biomedical subjects

M Hovi

Publications and source records attributed to M Hovi.

8 recordsLinked to original sources

Application of ribotyping and IS200 fingerprinting to distinguish the five Salmonella serotype O6,7:c:1,5 groups: Choleraesuis sensu stricto, Choleraesuis var. Kunzendorf, Choleraesuis var. Decatur, Paratyphi C, and Typhisuis.

Sixty-seven strains of the five described Salmonella serotypes having antigens 6,7:c:1,5, that is S. enterica serotype Choleraesuis sensu stricto, Choleraesuis var. Kunzendorf, Choleraesuis var. Decatur, Paratyphi C, and Typhisuis, were examined for 16S rrn profile ribotype, presence of IS200 and phenotypic characters, including rate of change of flagellar-antigen phase and nutritional character. Choleraesuis sensu stricto and its Kunzendorf variant had related but distinct ribotypes. Therefore, ribotyping appears to be a suitable method for differentiating Choleraesuis non-Kunzendorf from Choleraesuis var. Kunzendorf. Some strains of Paratyphi C had 16S profiles that resembled that of Choleraesuis non-Kunzendorf, while others resembled that of Choleraesuis var. Kunzendorf. The Typhisuis profiles were like those of Choleraesuis non-Kunzendorf, while the Choleraesuis var. Decatur profiles were unlike those of any of the other four groups. Furthermore, IS200 fingerprinting discriminated between Choleraesuis var. Decatur and the other strains with antigenic formula O6,7:c:1,5, and comparison of IS200 patterns showed a high degree of genetic divergence within Choleraesuis var. Decatur. Our findings show that ribotyping and IS200 fingerprinting, combined with classical microbiological methods, distinguish the groups Choleraesuis non-Kunzendorf, Choleraesuis var. Kunzendorf, Choleraesuis var. Decatur, Paratyphi C and Typhisuis.

Animals↗

Incidence of clinical mastitis in dairy herds in England.

The annual incidence of clinical mastitis was measured in 144 Holstein/Friesian dairy herds in England (average size 132 cows) during 1994, 1995 and 1996 by means of carefully defined mastitis indices. The mean annual incidence of the disease over the three-year period was 43.4 quarter-cases per 100 cows, and the disease affected 25.9 per cent of the cows in the herds, with 1.6 quarter-cases per affected cow. In terms of cow-cases, the mean incidence was 39.9 cases per 100 cows in the herd and hence the ratio of quarter-cases to cow-cases was on average 1:1. The proportion of repeat quarter-cases was on average 19.4 per cent, and the recurrence rate was 18.3 per cent. The new infection rate was 28.3 per cent.

Animals↗

Immunogenicity of a fusion protein linking the beta subunit carboxyl terminal peptide (CTP) of human chorionic gonadotropin to the B subunit of Escherichia coli heat-labile enterotoxin (LTB).

Human chorionic gonadotropin (hCG) is currently under investigation as an antigenic target in both anti-cancer and anti-fertility vaccines. Formulations studied to date show promise in clinical trials for both applications yet are expensive to produce and require frequented administration in order to maintain an effective antibody titer. We have engineered a fusion protein consisting of Escherichia coli heat-labile enterotoxin subunit B (LTB) genetically linked at its C terminus via a nine amino acid linker to the 37 amino acid carboxyl terminal peptide (CTP) of the hCG beta chain. This LTB-CTP fusion protein is stably expressed in bacteria and forms pentamers of full-length protein subunits. Purified LTB-CTP protein hCG-specific antibodies in mice without additional adjuvants.

Amino Acid Sequence↗

C-reactive protein serum levels in patients with ocular disease.

Hepatocyte derived C-reactive protein (CRP) is a sensitive indicator for inflammatory or infectious processes in a variety of tissues. As several other plasma proteins it is regarded as part of the acute phase response to a variety of tissue damage. CRP is commonly used in general medicine as a tool for the follow-up of especially bacterial infections. However, it has not been widely used in ophthalmology. In the present study CRP values in serum samples from 51 patients with various acute ocular diseases were determined semiquantitatively. High CRP levels were found most frequently in patients with either preseptal cellulitis (83.3%) or endophthalmitis (25.8%) whereas in the serum of patients with keratitis and uveitis, CRP exceeded 20 mg/l in only 18.7% of the cases. In a control group of 10 patients with retinal detachment the mean CRP level was 2.3 mg/l (SD +/- 0.98 mg/ml). The clinical significance and the prognostic value of CRP determinations during ocular diseases are discussed.

C-Reactive Protein↗

Protective immunity in mouse salmonellosis: comparison of smooth and rough live and killed vaccines.

Protective immunity against Salmonella infection was studied in a mouse model. To study specificity of protection we used smooth (O-4,5,12) and rough vaccines; live and killed vaccines of both types were compared. The protection was assessed by enumerating the number of bacteria in the livers, and by following survival of the mice after intravenous challenge with smooth O-4,5,12 bacteria. Passively transferred antibodies induced by the smooth vaccines had a small protective effect and those induced by the rough vaccines no protective effect in this model. Both live vaccines induced long-lasting protective immunity which was much stronger than that mediated by antibodies. Since the live rough vaccine induced protective immunity and contained no O antigen we conclude that the protective immunity induced by it was mainly cell-mediated and directed to other antigens than the O antigen, the target of protective antibodies. Both killed vaccines also induced protective immunity, but this was weaker than that induced by the corresponding live vaccine.

Animals↗

Salmonella, complement and mouse macrophages.

The structure of the polysaccharide chains that constitute the O antigen on the surface of Salmonella bacteria determines the rate of complement activation and C3b deposition on the bacteria. A fast-activating O antigen causes rapid C3-dependent opsonization of the bacteria injected intraperitoneally; as a consequence, the bacteria are taken up and killed by the resident peritoneal macrophages, and their virulence is low. A slow-activating O antigen protects the bacteria from opsonization in the peritoneal cavity, and is associated with higher virulence. However, if injected intravenously bacteria with either O-antigenic type are equally virulent; in the high complement concentration of the blood they become opsonized and taken up by macrophages in the liver and spleen, which are unable to kill them but instead provide a protected site for multiplication.

Animals↗

Plasmid-associated virulence of Salmonella enteritidis.

Plasmid-associated virulence of Salmonella enteritidis was studied using plasmid-cured and plasmid-reintroduced strains. The plasmidless strain was unable to grow in the liver of mice after intravenous inoculation. Reintroduction of the plasmid pEX106 from the original S. enteritidis fully restored its capacity to grow in the mice. The plasmid pEX102 of Salmonella typhimurium introduced into the plasmid-cured S. enteritidis had a similar effect. The smooth lipopolysaccharide character of the S. enteritidis strains was not affected by the presence or absence of the plasmid, and the same was true of their high resistance to complement in guinea-pig serum as such or with added antibody.

Animals↗