Prevalence and molecular detection of fluoroquinolone-resistant genes ( and ) in isolated from healthy broiler chickens.

AIM

The present study was carried out to determine the prevalence and molecular detection of fluoroquinolone-resistant carrying and genes in healthy broiler chickens in Mymensingh, Bangladesh, and also to identify the genes responsible for such resistance.

MATERIALS AND METHODS

A total of 65 cloacal swabs were collected from apparently healthy chickens of 0-14 days (n=23) and 15-35 days (n=42) old. The samples were cultured onto Eosin Methylene Blue Agar, and the isolation and identification of the were performed based on morphology, cultural, staining, and biochemical properties followed by polymerase chain reaction (PCR) targeting 16S rRNA genes. The isolates were subjected to antimicrobial susceptibility test against five commonly used antibiotics under fluoroquinolone (quinolone) group, namely gatifloxacin, levofloxacin, moxifloxacin, ofloxacin, and pefloxacin by disk diffusion method. Detection of and genes was performed by PCR.

RESULTS

Among the 65 cloacal samples, 54 (83.08%) were found to be positive for . Antibiotic sensitivity test revealed that, of these 54 isolates, 18 (33.33%) were found to be resistant to at least one fluoroquinolone antibiotic. The highest resistance was observed against pefloxacin (61.11%). By PCR, of 18 resistant to fluoroquinolone, 13 (72.22%) were found to be positive for the presence of . None of the isolates were found positive for .

CONCLUSION

Fluoroquinolone-resistant harboring genes is highly prevalent in apparently healthy broiler chickens and possesses a potential threat to human health.