Biomedical subjects

D Schimmel

Publications and source records attributed to D Schimmel.

At least 37 records · Page 2Linked to original sources

PubMed1990

[Further development of P. multocida vaccines for swine].

149 strains with antigen fractions of both A and D type could be found out of 446 P. multocida field strains of porcine origin. Most of them are producing the dermonecrotizing toxin. These A/D strains proved to be virulent in mice and piglets as well. In mice, the vaccination with one of the most virulent and immunogenic A/D strains, inactivated and A1(OH)3 adsorbed caused an immunity against challenge infections with P. multocida of types A, D and A/D. This effect could be confirmed on SPF piglets.

Animals↗

PubMed1990

[Immunoprophylaxis against an acute P. multocida type D infection in Cairina moschata].

An acute P. multocida infection led to severe losses in a big Cairina moschata fattening farm. All isolated strains belong to serogroup D. After testing the virulence and immunogenic properties of the isolated strains in NMRI mice, we used an highly virulent and immunogenic strain for developing an inactivated vaccine (formaline inactivated, Al (OH)3 adsorbed, with a content of 3 x 10(9) bacteria/ml). Two sc. immunizations of Cairina at an age of 10 and 24 days resulted in immunity. All immunized animals survived the challenge infection. The immunity was stable till the 8th week after the 2nd immunization, later the intensity of the immunity decreased. A threefold immunization procedure in the Cairina farm was very successful.

Acute Disease↗

PubMed1990

A group of indole-negative bovine strains with high deoxyribonucleic acid homology to Pasteurella multocida.

A group of nine bovine Pasteurella strains not producing indole were investigated for their taxonomic relationships with Pasteurella multocida, Pasteurella haemolytica and Pasteurella canis. For all strains, DNA-DNA hybridization has revealed a high genetic relatedness at the species level to P. multocida and significantly lower homologies of only 18-41% towards P. haemolytica and 11-15% towards P. canis. Guanine plus cytosine values of 38.0 to 42.1 mol% and several phenotypic characters have been found to be different from the established pattern for P. multocida subspecies. It is suggested that the strains represent a new taxon, possibly another P. multocida subspecies.

Animals↗

PubMed1990

[Bactericides against Pasteurella multocida in whole blood, plasma and lung lavage fluid of untreated and immunized young swine and calves].

The investigation of bactericidal effects in the whole blood and plasma of young pigs and calves against Pasteurella multocida has shown that such effects only come into being or are activated during the direct interaction between the host and pasteurellae, with effects being increased in previously immunized animals. The same is true for the antibodies which are detectable by indirect haemagglutination. There is no bactericidal effect in the concentrated lung lavage fluid against pasteurellae.

Animals↗

PubMed1990

[Typing and virulence testing of Pasteurella haemolytica field strains].

The greater part of 145 typed Pasteurella haemolytica strains from calf could be attributed to Type A 1. Hence, in the context of virulence testing, this is the most important type at present for calf. Clearly manifest pneumonia was caused in calf by other strains of Types A 2, A 6, A 12, and T 10 which were also tested for their virulence parameters. The same applied to a number of strains which had so far been characterised merely as T or A/T strains.

Animals↗

PubMed1989

[Experimental Mycoplasma bovis infection of the respiratory tract of calves].

Multiple intranasal experimental Mycoplasma (M.) bovis infection was induced to 22 calves and resulted in clinical manifestations. M. bovis was re-isolated from 17 of 24 lungs which had been altered by pneumonia. Pasteurella haemolytica was the only pathogen isolated from the pathologically affected lung of one of the experimental animals. The haematogenic proliferation phase was successfully identified in 5 of 8 examined calves. Arthritis was not recordable from any of the experimental animals. Interstitial and catarrhal to catarrhal-purulent bronchopneumonias were the most common histological findings. Peribronchial lymphoid cell accumulations occurred frequently, as time passed from onset of infection. Antibodies against M. bovis were detected in blood serum of infected animals by means of film inhibition, as of the 3. week from infection, and by means of indirect haemagglutination, as of the 4. week from infection.

Animals↗

PubMed1989

[Isolation and characterization of ts-mutants of Pasteurella multocida].

Temperature-sensitive mutants were isolated and characterised from wild strains of A, D, and A/D serotypes of Pasteurella multocida by mutagenic treatment, using N-methyl-N-nitro-n-nitrosoguanidine. The mutants differed from parent strains by growth intensity at 41 degrees C and 43 degrees C as well as by reduced virulence to mice and decreased toxin formation capacity. Mice were totally protected from intraperitoneal challenge infection, using the tenfold LD100, by two subcutaneous injections of 10(7) mutant germs.

Animals↗

PubMed1989

[Development of specific technics for the prevention of mycoplasma infections in swine].

Four experimental series were run in 2 experiments with 44 unweaned piglets to test non-inactivated vaccine from ts-mutant M-60 of Mycoplasma (M.) arginini and from attenuated strains of CH-2 M. hyorhinis, EP-29 M. hyosynoviae, M. suipneumoniae, and B-1 Acholeplasma laidlawii. Similar deviations of clinical and immunological parameters were recorded from piglets inoculated with the above vaccine and infected with pathogenic mycoplasma cultures. These deviations, however, were less strongly pronounced in animals which had been inoculated. Mycoplasma species were re-isolated from bronchial lymph nodes and lungs of 62.5% of inoculated piglets. Lasting residual virulence was recorded from the attenuated mycoplasma strains. That residual virulence had no substantial impact upon growth and development of the piglets under laboratory conditions, throughout the period of observation. The above results are likely to suggest the advisability of further studies for the development of a vaccine from ts-mutants and attenuated strains of pathogens of mycoplasmosis in swine.

Animals↗

PubMed1989

[25 years of Mycoplasma research in the Institute for Bacterial Animal Epidemic Research in Jena].

Twenty-five years of persistent research at the Jena Institute of Bacterial Animal Diseases have yielded substantive results of relevance to general knowledge and veterinary practice in the following fields: Mycoplasma species in farm animals-isolation, demands on culturing substrate, and differentiation; Virulence testing; Development, production, and application of diagnostic preparations; Development to full application maturity of diagnostic techniques and concepts for control of several mycoplasmal infections of relevance in terms of economy. The mycoplasma laboratory in Jena has become established as the reference centre for mycoplasma species in mammals for all CMEA member countries.

Academies and Institutes↗

PubMed1988