Nyúl eredetű Bordetella bronchiseptica törzsek virulencia faktorainak fenotípusos vizsgálata

Abstract

SUMMARY Background: Bordetella bronchiseptica is a widespread pathogen bacterium causing various respiratory diseases in mammals. Little is known about the background of infection of rabbits by B. bronchiseptica, although both asymp tomatic carriage and clinical manifestation of the disease generate economic losses for breeders. Moreover, rabbits as companion animals imply zoonotic risk, as well. Objectives: In this work, the phases of infection by B. bronchiseptica strains were investigated. Materials and methods: 40 B. bronchiseptica strains, isolated between 1984 and 2011 from rabbits in Hungary and other countries, were used in this study. The reach of the host was examined by motility assay under various circum stances (LB-37; LB-24; LB+MgSO4-37; LB+MgSO4-24). Adhesion was modelled by haemagglutination using rabbit, cattle and sheep erythrocytes, and the produc tion of adenylate cyclase-haemolysin toxin was studied by haemolysis. Results and Discussion: Most of the strains proved to be motile under all examined circumstances, but the greatest motility zones were measured after incubation at 37 °C on LB agar. Only one of the strains did not agglutinate any of the four types of erythrocytes. Rabbit erythrocytes were agglutinated by the highest number of strains. The lowest number of reactions were seen with cattle erythrocytes. Haemolysis was strongest on Columbia agar supplemented with 5% sheep blood. Supplementation with 5% horse blood resulted in weaker haemolysis. Haemolytic activity was not consistent between different passages of any strain. Results have shown that there are no signifi cant differences between Hungarian and foreign B. bronchiseptica strains. However, the behaviour and virulence of the strains is considerably infl uenced by environmental parameters.