Abstract of research

Molecular characterization of Quinolones and β-Lactams Resistant Salmonella Serovars Determinants in Diarrheic Calves, lambs and goats-kids in the Middle of Nile Delta, Egypt

Ashraf A. Abd El- Twab1, Fatma I. El-Hofy1, Amira Mohamed Rizk1

Abstract

of were subjected to bacteriological, biochemical, serotyping, sensitivity testing and PCR detection of resistance genes for β-Lactames and Quinolones. Ten isolates of Salmonella species were identified, as 7 isolates (4.7%) from calves (Salmonella Typhimurium, Salmonella Enteritidis, Salmonella saintpaul, Salmonella Langeveld and Salmonella Havana), 2 isolates (3.6%) from lambs (Salmonella Typhimurium, Salmonella Bardo) and one isolate (3.3%) from goat-kids (Salmonella Enteritidis) Salmonella isolates sensitivity to β-lacatmes was 0.00% for ampicillin, penicillin G, piperacillin, cephalexin, cefoxitin, ampicillin-sulbactam, ceftazidime, 10% for ceftriaxone and 20% for amoxicillinclavulanic acid, increased to 60% and 100% for aztreonam, imipenem respectively. Susceptibility of isolates to quinolones were 10% for ciprofluxacin, 20% to nalidixic acid, and 100% for each of norfloxacin and levofloxacin. PCR study showed beta-lactamase encoding gene, bla (TEM-1), was identified in 90% and the extended-spectrum beta-lactamase, (CIT) in 20% while bla (SHV) and acc in 80% of isolates. The detection was 50%, 40%, and 0.00% for FOX, MOX, and bla (OXA-1) genes, respectively. Plasmid-mediated quinolone resistance, qnrB, qnrS were detected in 80% while aac(6')- Ib-cr, was only in 50% of the isolates. Results showed a high incidence of β-lacatmase than quinolones resistance genes and higher isolate susceptibility to quinolone than to β-lacatmes which indicates higher efficacy and validity of quinolones. Results indicates quinolones LEV and NOR in addition to β- lacatmes imipenem are the drugs of choice for suspected salmonella cases.