Countrywide spread of OXA-48 carbapenemase in Lebanon: surveillance and genetic characterization of carbapenem-non-susceptible Enterobacteriaceae in 10 hospitals over a one-year period.

OBJECTIVES: To detect, characterize, and assess the genetic clonality of carbapenem-non-susceptible Enterobacteriaceae in 10 Lebanese hospitals in 2012. METHODS: Selected Enterobacteriaceae isolates with reduced susceptibility to carbapenems were subject to phenotypic study including antibiotic susceptibility, cloxacillin effect, modified Hodge test, and activity of efflux pump inhibitor. Carbapenemase genes were detected using PCR; clonal relatedness was studied by pulsed field gel electrophoresis. RESULTS: Out of 8717 Enterobacteriaceae isolated in 2012, 102 (1.2%) showed reduced susceptibility to carbapenems. Thirty-one (70%) of the 44 studied clinical isolates harbored blaOXA-48, including 15 Klebsiella pneumoniae, eight Escherichia coli, four Serratia marcescens, three Enterobacter cloacae, and one Morganella morganii. The majority of OXA-48 producers co-secreted an extended-spectrum beta-lactamase, while one had an acquired AmpC of the ACC type. In the non-OXA-48 producers, carbapenem resistance was attributed to the production of acquired AmpC cephalosporinases of MOX or CIT type, outer membrane impermeability, and/or efflux pump overproduction. DNA fingerprints revealed that OXA-48 producers were different, except for clonal relatedness among four K. pneumoniae, two E. coli, two E. cloacae, and three S. marcescens. CONCLUSIONS: Nosocomial carbapenem-non-susceptible Enterobacteriaceae are moderately spread in Lebanon and the predominant mechanism is OXA-48 production.

[Evolution of the antibiotic resistance of Streptococcus pneumoniae from 1997 to 2004 at Hôtel-Dieu de France, a university hospital in Lebanon]. / Evolution de la sensibilité aux antibiotiques de Streptococcus pneumoniae de 1997 à 2004, à l'Hôtel-Dieu de France, centre hospitalier universitaire au Liban.

Various rates of Streptococcus pneumoniae with diminished susceptibility to Penicillin G (PNSP) are reported worldwide, while resistance to cefotaxime and ceftriaxone is actually increasing among S. pneumoniae. The aim of this survey was to determine the evolution of the susceptibility and resistance of S. pneumoniae at our hospital, throughout the years 1997-2004. 582 S. pneumoniae strains, isolated from different patients with pulmonary disease, otitis media, bacteremia and/or meningitis have been observed. MIC to benzylpenicillin (P), ampicillin (AMP) and ceftriaxone (CRO) were determined by E-TEST. Susceptibility to erythromycin (ERY), cotrimoxazole (SXT), tetracycline (TE) and rifampicin (RA) were determined by agar diffusion. All tests were interpreted according to CA-SFM guidelines. The percentage of PNSP varied between 49.6 and 69%. S. pneumoniae with reduced susceptibility to benzylpenicillin had stable rates, while fully resistant S. pneumoniae decreased significantly. Resistance to ampicillin varied alongside with penicillin with a decrease of fully resistant S. pneumoniae. Strains intermediate to ceftriaxone also decreased significantly while those fully resistant were not detected, except for 1999 (1 strain). The resistance (I+R) to SXT and TE remained stable with small variations, but resistance to ERY increased up to 43% of isolated strains in 2004. Resistance to LVX and RA was absent, with unexpected levels for RA (1 and 5%) in 2002 and 2003.