Isolation and molecular identification of multidrug-resistant Pseudomonas aeruginosa isolated from broiler chickens in Fayoum, Egypt

In the poultry industry, the Gram-negative bacterium Pseudomonas aeruginosa is gaining importance as an emerging opportunistic pathogen with notable clinical implications. This Gram-negative pathogen can contaminate hatcheries, resulting in a range of severe respiratory symptoms, enteritis, septicemia, keratitis, sinusitis, omphalitis, nephritis, and rapid morbidity and mortality, which indicates the diverse pathogenic potential of this pathogen within avian populations. This study collected 480 samples (120 each) from liver, lung, gallbladder, and kidney of broiler chickens of different ages and examined bacteriologically. The overall isolation rates of P. aeruginosa were ranged from 70.8 to 83.3%. Phenotypically, the antibiogram of the selected isolates (n=30) revealed that 96.66% were resistant to three or more antibiotics from different antimicrobial groups, thus indicating multidrug resistance (MRD), of which the highest resistance was to amoxicillin 100%, piperacillin 96.66%, gentamycin 86.66% ofloxacin 80%, cefepime 63.33%, ceftazidime63.33%, levofloxacin 53.3% and ciprofloxacin 53.3% followed by apramycin 36.66% and doxycycline 36.66. In comparison, 66.6% of the isolates were sensitive to the amikacin. Polymerase chain reaction (PCR) was used for determining five resistance genes in ten selected MDR P. aeruginosa isolates. The result revealed that 100% of the tested isolates harbored the mexR and ampC resistance genes. Furthermore, the prevalence of blaOXA, ermB, and arr genes were 90, 80, and 50%, respectively.