Listeria isolation from foods of animal origin.

Microbiological examination of Listeria, isolated from foods of animal origin was carried out during the period 1986-1987. A total of 642 samples from chicken, beef and pork raw meats, fish, eggs and from the environment were investigated. Using the cold technique, Stuart's transport medium, tryptose broth and Ralovich's medium, 76 Listeria strains of serogroup 1 and 2 were isolated.

Characteristics of listeria strains, isolated from micromammalia in Bulgaria.

56 Listeria strains isolated from the intestine contents of 13 species of micromammalia in Bulgaria were studied. 10 of the strains belong to the serovars 1/2a, 4A, 4b and 5 of Listeria monocytogenes and 44 of the strains belong to 10 antigenic variants of Listeria innocua. According to their characteristics these strains could hardly cause diseases in humans or domestic animals.

A natural focus of infection with leptospires of the serovar lora in Bulgaria.

A natural focus of infection with leptospira serovar lora (Australis serogroup) was discovered in the Tundga River Valley, South Bulgaria. 1 672 micromammals belonging to seven species were investigated. Serologically and bacteriologically a high incidence of infection was established.

Serological characteristics of the Leptospira serogroup Pomona. II. Changes in the agglutination and absorption properties of the reference strains after formalin- and heat-inactivation.

After formalin or heat-inactivation for 30 minutes at 56 degrees C, the absorption properties of some Pomona serogroup strains diminish, which indicates that they have thermolabile (Pomona, CZ 299U and LT 796) or formalin-labile (Pomona and 5621) minor antigenic factors. The agglutination properties of the various strains change differently after inactivation though not in parallel with the absorption properties.

Serological characteristics of the Leptospira serogroup Pomona. I. Factor analysis of the reference strains.

The factor analysis of the Leptospirae of the Pomona serogroup discloses the presence of 4 main factors in this group on the basis of which 4 serovars, namely pomona, mozdok, tropica and proechimys may be accepted in this group. It is proposed that the Monjakov and the LT 1026 strains be referred to the pomona serovar. One of the established main antigens (P-4) is of the complex nature containing both thermostable and thermolabile compounds.