Detection for the most suitable antibiotic and disinfectant for pseudomonas aeruginosa isolated from pneumonic and apparently healthy farm animals

Abstract

The present study was carried out on 550 samples (nasal, tracheal swabs and lung tissues) collected from pneumonic and apparently healthy cows and buffaloes. The bacteriological examination revealed that Pseudomonas aeruginosa was isolated from 172(41.1%) out of 419 cow’s samples and from 46(35.1%) out of 131 buffalo’s samples. From 172 cow’s isolates there were 144 isolates related to serotype (1) and 28 isolates were untypable while buffalo’s positive isolates revealed that 40 isolates were belonging to serotype (1) and 6 isolates were untypable. The effect of disinfectants as phenol, formalin and ethyl alcohol on viability of tested strains showed that 3.0% phenol could kill all tested strains after 5 minutes, but 3% concentration of formalin has a marked killing effect on the growth of P. aeruginosa within 10–15 minutes, while 40% ethyl alcohol dilution could kill P. aeruginosa after 10 minute. Forty P. aeruginosa isolates were tested for antibiotic susceptibility to 12 chemotherapeutic agents. The most effective antibiotic was gentamycin (95.0%) then streptomycin (87.5%) and amikacin (75%), all tested strains were completely resistant to tetracycline, cephalothin and ampicillin. It is concluded that P. aerouginosa is one of the most important cause of pneumonia in cows and buffaloes also it resists many disinfectants and remain viable except by using appropriate concentration. In vitro antibiotic sensitivity test showed that most strains were susceptible to gentamycin and amikacin although they resist many types of antibiotics.