Diagnostics of associated coliform mastitis of cows in industrial complex conditions

Mastitis is one of the main problems of dairy farming, causing significant economic damage due to reduced productivity, treatment costs and early culling of sick animals. As a rule, mastitis has a bacterial etiology, occurs both as a mono- and associated infection. We conducted a bacteriological monitoring study of cow milk samples and swabs from milking equipment in an industrial complex for milk production in the Leningrad region. 120 milk samples were examined for clinically expressed (45) and latent mastitis (15), as well as milk samples from healthy cows (30) and swabs from milking equipment (30). 94 isolates of microorganisms were obtained, in which biological properties were established. Susceptibility to antimicrobials was determined to: cephalosporins, carbapenems, aminoglycosides, monobactams, tetracyclines, sulfonamides, quinolones, polymyxins. The etiological factor of the occurrence of mastitis in cows in this farm is the association of coliform microorganisms and Pseudomonas spp. The main pathogen is Klebsiella pneumoniae subsp. pneumoniae. In 36.7% of cases, this is an association of K. pneumoniae and Proteus mirabilis. In 14.4% there was an association of K. pneumoniae and Pseudomonas aeruginosa, in 37% of cases – K.pneumoniae and Escherichia coli, in 11.9% of cases – K. pneumoniae, Staphylococcus aureus and Shewanella spp. Isolates of Shewanella spp. had lecithinase and hemolytic activity, were halophilic and slightly virulent for white mice with subcutaneous infection. Almost all isolated microorganisms were resistant to at least one antimicrobial. Thus, a biocenosis of microorganisms has been formed in this livestock enterprise, which are potential pathogens of purulent-septic diseases, including mastitis. To prevent mastitis disease, comprehensive measures are needed to sanitize livestock premises and equipment in order to eliminate the persistent association of microorganisms in it.

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