Biomedical subjects

R Mutters

Publications and source records attributed to R Mutters.

42 records · Page 3Linked to original sources

PubMed1986

Taxonomic relationship of selected biogroups of Pasteurella haemolytica as revealed by DNA:DNA hybridizations.

Genetic investigations of selected bovine and ovine strains of Pasteurella haemolytica sensu stricto (biogroup 1), P. haemolytica biogroups 2, 3, 5 and 9, P. testudinis and porcine isolates of so-called P. haemolytica, tentatively designated taxon 15, confirmed the existence of these phenotypically delineated taxa. Evidence was further obtained to indicate that P. haemolytica biogroups 1, 2, 3, 5 and 9 and P. testudinis constitute a new genus within the family Pasteurellaceae Pohl 1981, and that P. testudinis represents a "missing link" between so-called P. haemolytica biovars A and T. The proposed genus seems to contain several new species. Additional investigations are, however, indicated before final conclusions can be drawn. The authors desist from proposing genus and species names for the same reasons. Porcine strains provisionally named taxon 15 seem to constitute a separate group within the family Pasteurellaceae Pohl 1981, underlining the distinct degree of specificity members of this family show for host species.

Animals↗

PubMed1985

Characterization of Pasteurella species isolated from lungs of calves with pneumonia.

During routine bacteriological examination of pneumonic calf lungs it was experienced that many Pasteurella multocida-like isolates had a fermentation pattern different from what is generally accepted for P. multocida sensu stricto. Forty-one out of 50 strains selected for further investigation were phenotypically related and formed a group of indole-, mannitol-and sorbitol-negative P. multocida-like strains, which was tentatively designated taxon 13. Deoxyribonucleic acid/deoxyribonucleic acid hybridizations including both ornithine positive and ornithine negative strains of taxon 13 allowed the classification of the former as P. multocida biovar 6 and the latter as V factor independent strains of Haemophilus avium.

Animals↗

PubMed1984

Phenotypic differentiation of Pasteurella sensu stricto and the Actinobacillus group.

The current classification of recognized actinobacilli and pasteurellas does not allow differentiation of the two genera by their phenotypic features. Recent investigations of their genetic relationships have shown that several species hitherto assigned to the genus Pasteurella are more closely related to the actinobacilli. Moreover, some recently described taxa were located by DNA-DNA hybridization in one or the other of the two genera. On the basis of the genetic system, improved identification keys have been devised which separate the taxonomic groups on the genus and species levels according to an appropriate set of biochemical characteristics.

Actinobacillus↗

PubMed1984

Lack of evidence for the occurrence of Pasteurella ureae in rodents.

The taxonomy of five typical human isolates of Pasteurella ureae, one strain of Actinobacillus hominis, and three murine isolates which had been designated as Pasteurella ureae in published reports were re-examined. Their taxonomic relationships were investigated by both conventional phenotypic characterization and by DNA/DNA hybridization using the renaturation method. The human Pasteurella urea strains were highly homogeneous in their phenotypes and in their DNA reassociation. The strain of Actinobacillus hominis studied was genetically distinct from Pasteurella ureae, but was located, like Pasteurella ureae, in the Actinobacillus group. The remaining strains exhibited only low DNA relatedness with Pasteurella ureae and each other; this agreed with their phenotypic divergence. Two of the murine isolates were identified as indole-negative variant strains of Pasteurella pneumotropica sensu stricto (i.e., type Jawetz), or of the type Heyl of Pasteurella pneumotropica, respectively. The remaining murine isolate appears to represent a hitherto unrecognized species of Pasteurellaceae. So far, there is no evidence for the occurrence of Pasteurella ureae outside the human host.

Animals↗

PubMedDate not supplied

Chronic osteomyelitis in a new rabbit model.

Dogs, rats, and rabbits are the most suitable species to induce chronic osteomyelitis and to study different methods of treatment. In rabbits, the incidence of and mortality from Staphylococcus aureus-induced osteomyelitis of the tibia depends on the method of prelesions and the amount and virulence of species-specific bacteria used. In this study two different lesions were combined simultaneously in the medullary canal of the femurs by aspiration of bone marrow, leaving the insertion needle in situ. A sclerosing agent was then inoculated followed by 300,000 bacteria of a rabbit-derived S. aureus strain to initiate infection. With this method, the incidence of chronic progressive osteomyelitis of the femur was increased to 100%. A relatively low mortality was observed, probably due to a lower number of inoculated bacteria as compared to other rabbit models described. The incidence of acute to chronic osteomyelitis was diagnosed by local signs, x-rays, microbiological recovery, and gross pathology of the femur. Initial fever, weight loss, abscess formation in soft tissues, and pain on palpation characterize the clinical features in the course of development of this chronic disease.

Animals↗

PubMedDate not supplied

Repetitive pneumoperitoneum with ozonized oxygen as a preventive in lethal polymicrobial sepsis in rats.

The aim of this study was to test whether repetitive pretreatments of rats with ozonized oxygen at relatively low gas volumes into the abdomen (20 ml per rat per day) have any beneficial or detrimental effects on the course of a polymicrobial-induced lethal peritonitis. Peritonitis was induced in a surgical or a nonsurgical model by usage of fecal material from the cecum. As the biological read out we used the mortality analysis. To include possible mechanisms by which ozone might influence the septic outcome, we characterized the gene expression of the pro-inflammatory cytokines IL-1beta, IL-2, and TNF-alpha mRNA in lymphoid organs. In both models, we found a significant beneficial influence of a dose-dependent O(2)/O(3 )pneumoperitoneum on the survival rate when compared to control animals or to room air. The ozone-enhanced survival seems to be independent from altered cytokine expression because there were no differences noticed in the levels of bacterial-induced gene expression of IL-1beta and TNF-alpha in septic animals pretreated with ozonized oxygen when compared to control animals.

Animals↗