ISOLATION AND ANTIMICROBIAL RESISTANCE OF MANNHEIMIA HAEMOLYTICA ON DAIRY FARMS IN SIBERIA

摘要

The frequency of Mannheimia haemolytica isolation on dairy farms in Siberia and the Republic of Kazakhstan in the period from 2006 to 2016 has been determined. Characterisation of phenotypes, biochemical and antimicrobial resistance profiles was carried out for 54 strains. Typing by the leukotoxin gene (lktA) was performed using the PCR. The isolates were classified into 7 lktA-negative and 47 lktA-positive strains. The highest prevalence of antimicrobial resistance was observed to benzylpenicillin (33.3%) and the lowest prevalence – to tulathromycin and sulfonamides (1.9%). Resistance of M. haemolytica strains isolated on the farms of the first category to the new generation antimicrobial drugs (spectinomycin and tulathromycin), suggested that these strains have been imported from abroad: a strong reason to implement a continuous system for surveillance of the circulation of resistant bacterial variants with respect to effective antimicrobial therapy.