ANTIMICROBIAL ACTIVITY OF AMOXICILLIN TO THE PATHOGENS OF RESPIRATORY DISEASES IN PIGS
The effectiveness of antibiotic therapy in the treatment of respiratory diseases of bacterial etiology depends on the action spectrum of antimicrobial agent and the level of susceptibility of pathogen or pathogens of disease to his actions. The aim of the study was to investigate the antimicrobial activity of β-lactam antibiotic amoxicillin against microorganisms, pathogens of respiratory diseases in pigs. For studies from pigs 2 to 4 months of age with pneumonia biological material (blood, exudate from the nasal openings) was selected. Studies were conducted with recognized microbiological methods - by diffusion in agar using standard discs with antibiotics and the method of successive serial dilutions in liquid nutrient medium. Test of antimicrobial sensitivity of biomaterial microflora showed different levels of sensitivity of microorganisms to antibiotics, which primarily explains the unlike spectrum of activity of antibacterial agents. Based on the results of the test, microflora isolated from 80% of samples proved to be sensitive to amoxicillin. Strains of Enterococcus faecalis, Streptococcus suis and Escherichia coli were isolated and identified from biological material. Accordingly of minimum inhibitory concentration ( MIC) of amoxicillin 81.25 % of isolates of enterococci, and all isolates of streptococci and E. coli were susceptible and moderately susceptible. Results of determination of MICs of amoxicillin showed that this antibiotic exhibits a high level of bacteriostatic activity in relation to the selected strains and its action spectrum covers both Gram-positive and Gram-negative bacteria. Research of sensitivity of bacteria, pathogens of pneumonia in pigs, to amoxicillin showed that this chemotherapeutic agent is antibiotic of broad-spectrum antimicrobial activity and remains the drug of choice in the treatment of swine respiratory infections of bacterial etiology caused by susceptible strains of microorganisms to amoxicillin.