Serotyping and antibiotic resistance patterns of isolated Salmonella from broiler chickens in Ahvaz

Salmonellosis is one of the most important zoonotic diseases. Antimicrobial therapy is an important tool in reducing both the incidence and mortality associated with Salmonella infections, but the indiscriminate use of antibiotics in poultry farms can lead to the emergence of resistance and inefficacy of antimicrobials. Moreover, transmission of the resistant strains to humans through food chain could be a menace to public health. This study was conducted to determine serogroup and antibiotic resistancepatterns of Salmonella isolates recovered from 25 broiler chicken farms in Ahvaz. All isolates were examined for serogroup using commercial antiserum, and for resistance to the most commonly used antibiotics in poultry (enrofloxacin, florfenicol, fosfomycin, lincospectin, sultrim and doxycycline) and humans (gentamicin, amoxiclav, ciprofloxacin, cefalexin, cefotaxime and ceftriaxone) by Kirby-Bauer disc diffusion method. The Salmonella isolates belonged to serogroups B (two isolates), C (three isolates) and D (45 isolates). Out of 50 isolates, 24 (48%) were resistant to one or more antibiotics. All isolates were sensitive to florfenicol, sultrim, cephalexin and ceftriaxone. The highest and lowest rates of resistance were observed against lincospectin (36%) and amoxiclav (2%), respectively. The high prevalence of resistant salmonellae among broilers indicates that the administration of antimicrobial drugs has to be made with more caution.
Conflict of interest: None declared