Occurrence of Plasmid-Mediated Quinolone Resistance Determinants and rmtB Gene in Salmonella enterica Serovar Enteritidis and Typhimurium Isolated from Food-Animal Products in Tunisia.

Nazek Al-Gallas (1) , Mohamed Salah Abbassi (2) , Becher Gharbi (1) , Molka Manai (1) , Mohamed N Ben Fayala (1) , Raghda Bichihi (1) , Amna Al-Gallas (3) , Ridha Ben Aissa (1)

1 Institut Pasteur de Tunis
2 Laboratoire de Recherche de Bactériologie
3 Massachusetts Eye and Ear Infirmary (affiliated with Harvard Medical School)

Abstract Four hundred and thirty Salmonella isolates, recovered from various food-animal products, were tested for nalidixic acid resistance, plasmid-mediated quinolone resistance, and genetic relationship. One hundred fifteen isolates (113 Salmonella serovar Enteritidis and two Salmonella serovar Typhimurium isolates) of 430 (26.7%) Salmonella isolates exhibited nalidixic acid resistance. Polymerase chain reaction screening for qnrA, qnrB, qnrS, qepA (encoding fluoroquinolones resistance) and rmtB (encoding aminoglycosides resistance) showed that 5 (1.16%) isolates were positive for qnr- and qepA-type genes, and the aac(6')-Ib-cr gene was observed in two (1.7%) Enteritidis isolates concomitantly with qnrA or qnrB. The co-occurrence of qepA and rmtB in one Typhimurium isolate is noteworthy. Pulsed-field gel electrophoresis revealed a high genetic homogeneity of nalidixic-resistant isolates and the persistence of clonal clusters over 4 years in different regions in Tunisia and from various food-animal products. To the best of our knowledge, this is the first report of co-occurrence of qepA and rmtB in a Salmonella strain.

Domaines: Sciences du Vivant [q-bio]

Nazek Al-Gallas, Mohamed Salah Abbassi, Becher Gharbi, Molka Manai, Mohamed N Ben Fayala, et al.. Occurrence of Plasmid-Mediated Quinolone Resistance Determinants and rmtB Gene in Salmonella enterica Serovar Enteritidis and Typhimurium Isolated from Food-Animal Products in Tunisia.. Foodborne Pathogens and Disease, 2013, 10 (9), pp.813-9. ⟨10.1089/fpd.2012.1466⟩. ⟨pasteur-00857262⟩