Influence of antibiotics on growth dynamics and movement ability of Salmonella rods.

Variety of traits important in diagnostics and epidemiology of pathogenic microorganisms may change due to antibiotics. Movement ability, that is characteristic for every serovar except from Salmonella Gallinarum-Pullorum, is important to salmonellas. In own experiments using semi-fluid MSRV medium, it was found that a decrease in salmonella sensibility to selected antibiotics and chemiotherapeutics due to passage might lead to weakening of its movement ability.

Lipid peroxidation as the additional indicator of transport stress in broilers.

Stressful conditions (transport, temperature fluctuations, infections and excessive crowding) lead to dysfunction of immunological mechanisms in birds. They influence the lipid balance what manifests itself through the increase of the malonodialdehyde (MDA) level, reacting with the 2-thiobarbituric acid (TBA), what is an indicator of lipid peroxidation. In the case of birds, the classical indicator of the stressful reaction is the heterophile/lymphocyte ratio (H/L), which changes depending on the stress intensity.

Evaluation of Mannheimia haemolytica leukotoxin prepared in nonsupplemented and BSA or FBS supplemented RPMI 1640 medium.

Mannheimia haemolytica leukotoxin (Lkt) is the major factor that contributes to lung injury in bovine pneumonic pasteurellosis. Supernatant preparations containing Lkt produced by M. haemolytica serotype 1, grown in RPMI 1640 medium supplemented with BSA or FBS and without supplements were evaluated during this study.

Screening the keratinolytic activity of dermatophytes in vitro.

Sixteen strains out of 12 species dermatophytes were examined in respect to their ability of utilizing keratin substrates as the only sources of C and N. The employed keratin substrates included a solubilized preparation of feather keratin (KS) and native keratin, guinea pig hair and chicken feathers. It has been shown that the preparation KS constitutes a convenient model for a preliminary estimation of fungal keratinolytic activity and it can be a source of information about the localization of these enzymes.

Sensitivity and specificity of a modified agar gel precipitation test and its application to the diagnosis of enzootic bovine leukosis.

Sensitivity and specificity of a modified agar gel immuno-diffusion (AGID) test for the diagnosis of enzootic bovine leukosis was compared in 609 sera using the standard method, the modified test, and ELISA. The modifications concerned the composition of agar gel (1.8% Bacto-agar Difco), addition of polyethylene glycol (PEG 6000, 4%) and enlarging the diameters of the wells from 6 to 10 mm for sera.

Early immunization of calves with an inactivated vaccine against trichophytosis.

The investigations demonstrated that the inactivated vaccine against trichophytosis, elaborated by the authors, induced immune response in calves, aged 5-8 days. The state of immunity was assessed in vitro by the leukocyte migration inhibition test, and in vivo by the allergic test and the challenge test. In all vaccinated calves (10 animals) there occurred delayed hypersensitivity and in six cases also a significant leukocyte migration inhibition.

Intracellular keratinase of Trichophyton gallinae.

Trichophyton gallinae could grow on agar medium containing chicken feathers as sole sources of carbon and nitrogen, but it could not utilize human or guinea pig hair. The fungus grows rapidly when feather keratin solubilized in dimethyl sulphoxide was included in the growth medium. Keratinase activity could be detected by release of amino acids from solubilized keratin and by creation of zones of lysis in gel diffusion assay.

Lipid composition of the mycelial and spore forms of Trichophyton verrucosum.

Neutral lipid composition and that of phospholipids of mycelial and spore forms of Trichophyton verrucosum were examined. It was found that arthrospores had more than twice as high content of lipids (99.3 mg/g) than the corresponding mycelial form (44.