Antibiotic resistance of P. aeruginosa in the presence and absence of pyocyanin pigment

Abstract

Purpose: study of antibiotic resistance of Р. aeruginosa strains in the presence and absence of pyocyanin pigment. Materials and methods. Bacteriological studies of pathological material from "asphyxiated embryos", sick chickens and forcibly killed or dead adult birds were carried out according to generally accepted methods. Cultures from bone, brain, heart, liver, spleen, gall bladder, muscles and other organs were carried out on simple, selective and differential diagnostic nutrient media. The sensitivity of P. aeruginosa isolates to antibacterial drugs was determined by diffusion in agar according to the generally accepted method. The results. The obtained results of studies by the diffusion method in agar indicate that the proportion of resistant to the studied antibiotics among non-pigmented isolates was on average 79.00 % (60-100) %, and among strains that formed pyocyanin - 51.00 % (25-100) %. 60.00 % - 90.00 % of resistant non-pigmented isolates were found to fluoroquinolones, 60.00-70.00 % to cephalosporins, 60.00-97.00 % to aminoglycosides. To representatives of semisynthetic penicillins, tetracyclines, and macrolides - 100 % of resistant isolates that did not synthesize pyocyanin were found. Among P. aeruginosa isolates that synthesized pigment, 25.00-40.00 % were resistant to fluoroquinolones, 30.00-35.00 % to cephalosporins, 25.00-50.00 % to aminoglycosides, representatives semi-synthetic penicillins, tetracyclines, macrolides - 100 % of the studied strains. Conclusions. The absence of pigment formation in P. aeruginosa isolates, obtained in association with bacterial pathogens, is not accompanied by the absence of antibiotic resistance. 28 % more antibiotic-resistant isolates were found among non-pigmented isolates compared to isolates that synthesize pyocyanin pigment. The data presented emphasize the need for the use of differential media for the isolation of P. aeruginosa in order to identify non-pigmented strains and prescribe appropriate treatment, which, accordingly, will prevent the spread of latent forms of infection