Genetic relatedness between ciprofloxacin-resistant Salmonella Kentucky isolated from humans and poultry meat
Abstract number: P1233
Bouchrif B., Timinouni M., Zerouali K., Cohen N., Ennaji M., Perrier-Gros-Claude J.D., Weill F.X.
Objectives: To compare Salmonella enterica serotype Kentucky strains (Salmonella Kentucky) resistant to ciprofloxacin isolated in France from travellers returning from Morocco with those from raw poultry meat produced in Morocco.
Methods:Salmonella Kentucky strains from poultry meat (n = 3) have been identified between December 2006 and June 2007 during a food safety survey conducted since 2004 in Pasteur Institute from Morocco. Strains from human origin (n = 3) have been isolated from travelers returning from Morocco (2006: n = 3; 2007, n = 3), and from a patient hospitalised in the Ibn Rochd Hospital (Casablanca) in 2006. Nalidix acid and ciprofloxacin MICs were performed by E-Test. To identify the mechanisms of resistance to ciprofloxacin, the quinolone-resistance determining regions of gyrA and parC were sequenced and the presence of plasmid-mediated quinolone resistance genes (qnrA-B-S, aac(6')-Ib-cr) were tested for all isolates. All isolates were genotyped by pulsed-field gel electrophoresis (PFGE) with XbaI restriction following PulseNet's running conditions.
Results: Among the 13 strains, 9 (poultry meat, n = 3; patients, n = 3) were resistant to nalidixic acid and to ciprofloxacin (MIC > 16 mg/l, >1 mg/l respectively) and have the same amino-acid substitutions within gyrA and parC (gyrA: Ser83-Phe, Asp87-Asn; parC: Ser80-Ile). Within parC, an additional substitution (Thr57-Ser) was observed. This substitution, however, did not appear to be associated with quinolone resistance because it was also identified in nalidixic acid-susceptible isolates. All strains were negative for plasmid mediated quinolone resistance genes. Among quinolone-resistant isolates, 2 PFGE patterns were displayed: the first one (P1) was observed in all poultry isolates and 4 human isolates; the second one (1 traveler isolate) shared 80% identity with P1. For quinolone-susceptible strains, 3 PFGE patterns were displayed and shared less than 50% identity with previous PFGE profiles.
Conclusions: this study showed clearly the close genetic relatedness among ciprofloxacin-resistant Salmonella Kentucky isolates and identified poultry meat as a probable source for human contamination. Moreover, it can be assumed that an unique ciprofloxacin-resistant Salmonella Kentucky has spread all over different poultry flocks in the Casablanca's region.
|Session name:||18th European Congress of Clinical Microbiology and Infectious Diseases|
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