Prevalence of the Pasteurellaceae bacteria in cattle farms of Moscow and Tver regions

Pasteurellaceae bacteria are etiological agents of various animal diseases. Representatives of this family can be part of the "Bovine respiratory disease complex"" - a set of viral and bacterial pathogens that cause respiratory diseases in cattle. The aim of our work was to study the prevalence of Pasteurella multocida, Mannheimia haemolytica, Bibersteinia trehalosi, and Histophillus somni in calves aged 2 to 6 months in 37 farms in Moscow and Tver regions. Respiratory swabs were examined by Real time PCR. P. multocida DNA was found in all 37 farms (89% of samples). The genetic material of M. haemolytica and H. somni was detected less often - in 28% and in 18.5% of the samples. B. trehalosi DNA was detected in 3% of the samples from 8 farms. In one sample, P. multocida type F was detected, in 90.72% of positive P. multocida samples the presence of type A was confirmed. There was no circulation of P. multocida serotypes B, D, and E. Monoinfection with P. multocida was recorded only in 6 farms out of 37. In all other farms, a combination of two or more studied microorganisms was detected. An association of four pathogens was registered in four farms. The analysis of the frequency of P. multocida, M. haemolytica, B. trehalosi, and H. somni DNA detection in calves showed no correlation with the age of the animals. This may indicate that immune status and conditions of maintenance and care in the farm are of greatest importance in Pasteurellaceae prevalence in cattle.