Avirulence of a spontaneous Francisella tularensis subsp. mediasiatica prmA mutant.

Francisella tularensis, the causative agent of tularemia, is divided into three subspecies. Two of these, subspecies holarctica and tularensis, are highly pathogenic to humans and consequently relatively well studied. The third subspecies, mediasiatica, is rarely isolated and remains poorly studied.

Pecularities of Candida yeast identification by mass spectrometric analysis (MALDI-ToF MS).

To carry the comparative analysis of sample preparation methods for the most effective identification of Candida yeast by mass spectrometric analysis. 265 strains of yeast and yeast-like fungi isolated from the sputum of patients with pneumonia were investigated. The selected strains were identified by conventional methods (cultural, morphological, tinctorial, enzymatic properties) and MALDI-ToF MS using the Autoflex speed III Bruker Daltonics mass spectrometer (Germany) and Flex Control software.

[ROLE OF VARIOUS ANTIGENIC PREPARATIONS OF FRANCISELLA TULARENSIS IN FORMATION OF ALLERGY REACTION IN HUMANS AND ANIMALS].

Aim: Study the role of LPS in induction of anti-tularemia immunity in humans and animals.

Materials And Methods: Activity of various antigenic preparations of tularemia microbe, including highly purified from protein and S- and R-LPS, was studied using leukocytolysis reaction with blood of vaccinated humans and guinea pigs and skin allergy test (guinea pigs).

Results: Only the whole cells of Francisella tularensis, killed in protein non-denaturating conditions and conserving full S-LPS structure (tularin⁺) were shown to be inductors of delayed-type hypersensitivity reaction.

[Comparative analysis of parameters of humoral and cell specific immunity in individuals immunized with a live tularemia vaccine].

Aim: Comparative analysis of parameters of humoral and cell immunity in individuals, vaccinated against tularemia.

Materials And Methods: Sera and blood samples of 258 immunized individuals were studied by indirect hemagglutination and leukocytolis with tularin reaction.

Results: 73% of the examined individuals had both specific antibodies and positive values of cell immunity.

[Features of resistance formation to beta-lactam antibiotics in Francisella tularensis subsp. mediasiatica].

Aim: Determination of penicillin resistance features in tularemia causative agents of the mediasiatica subspecies, stability evaluation of differences in strains of various taxa and development of a rapid method of F. tularensis intraspecies differentiation.

Materials And Methods: Beta-lactamase activity was determined in 30 strains of Francisella genus bacteria by quantitative iodometric method.