Identification of the capsule type of <i>P. multocida</i> strains by phenotypic methods in comparison with the multiplex PCR-method

Abstract

Relevance. Pasteurellosis is a group of zoonotic infectious diseases caused by Pasteurella multocida. According to the antigenic composition, P. multocida is divided into 5 serogroups (A, B, D, F and E). Pathogenic and virulent properties of various serogroups and serotypes of the pathogen in different animal species vary widely and are a marker for determining their role in the development of the disease. Typing of P. multocida strains by capsule groups is an important condition for a comprehensive assessment of the epizootic situation, including for solving the issue of specific disease prevention.Methods. 82 strains of P. multocida from the collection of FGBI «VGNKI», isolated in different years from various animals, were used in the work. Phenotypic typing of pasteurella strains by capsule groups according to Carter was carried out in a test for the detection of hyaluronic acid in a pasteurella capsule and by the type of reaction in a tripaflavin sample. Strains giving a positive reaction with staphylococcus hyaluronidase wereassigned to capsule group A. If the test culture did not belong to group A, but was positive when examined in a tripaflavin sample, it was assigned to capsule group D.Results. Discrepancies between the results of phenotypic typing of pasteurella strains by capsule groups and by PCR were established. The results of typing did not coincide between PCR and Carter typing for capsule group A with respect to 25 strains, for capsule group D with respect to 5 strains and for capsule group B with respect to 5 strains. The number of untyped or doubtful phenotypic properties of pasteurella strains was 29.73%, untyped by PCR 2.46%. Hyaluronidase and acriflavin tests, unlike the PCR-method, do not provide an opportunity for typing pasteurella groups E and F.