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.

Antimicrobial susceptibility patterns of Haemophilus influenzae and Streptococcus pneumoniae isolates in a Beirut general university hospital between 2000 and 2004

Susceptibility patterns of Streptococcus pneumoniae and Haemophilus influenzae collected over a 5-year period in a Beirut general university hospital were studied. Only 40.6-50% of S. pneumoniae isolates were susceptible to penicillin G. Susceptibility to clindamycin and erythromycin decreased from 94.1% and 89.7%, respectively, in 2000 to 75% and 71.9%, respectively, in 2004. All isolates were susceptible to ceftriaxone, ciprofloxacin and vancomycin. For H. influenzae, no resistance was observed to amoxycillin-clavulanate, ceftriaxone, ciprofloxacin and rifampicin, with >92% of isolates showing susceptibility to cefuroxime, chloramphenicol, erythromycin and tetracycline. The proportion of beta-lactamase-positive isolates varied between 22.7 and 30.8%.

[Prevalence and susceptibility patterns of extended-spectrum betalactamase-producing Escherichia coli and Klebsiella pneumoniae in a general university hospital in Beirut, Lebanon]

Extended-spectrum betalactamases (ESBLs) are recognized worldwide as a problem in hospitalized patients. Their prevalence among clinical isolates of Enterobacteriaceae varies between countries and institutions. We studied the evolution of ESBL production by clinical isolates of Escherichia coli and Klebsiella pneumoniae and analyzed the patterns of susceptibility of these isolates to different antimicrobial agents in a general university hospital in Beirut. Of the 4299 isolates of E. coli and 1248 isolates of K. pneumoniae tested over the five years, 2.0% of the E. coli and 20.0% of K. pneumoniae were ESBL producing. A clear decrease in the susceptibility to all antibiotics was observed between 1999 and 2001, and no resistance to imipenem was detected. The isolates were distributed between the Intensive Care Unit (ICU), medical wards, outpatients, and other origins. The highest numbers were found in the ICU (E. coli 28.1% and K. pneumoniae 34.8%). Three phenotypes of resistance to cefotaxime and ceftazidime were observed on the basis of microbiological results. The present study was the first to assess the occurrence and susceptibility patterns of extended-spectrum betalactamase-producing Enterobacteriaceae in Lebanon.

[Post-varicella thrombosis and factor V Leiden mutation]

BACKGROUND

Varicella is a benign infectious disease that is rarely complicated by thrombosis. Factor V Leiden (FVL) mutation is presently recognized as the most common inherited cause of thrombosis. From a case report the link between varicella associated thrombosis and FVL is discussed.

CASE REPORT

An eight year-old boy was admitted on 15th day of a varicella infection for difficulty to walk and painful legs. Doppler ultra sound of the lower limbs venous system showed thrombosis of the left iliac vein and femoral veins. Thrombophilia work-up revealed a FVL heterozygotic status for the patient. Biological screening for molecular abnormalities associated with thrombophilia led to the detection of a heterozygous inherited FVL mutation in the patient. Response to heparine followed by oral anticoagulant treatment was good.

CONCLUSION

Thrombosis associated with varicella in child is a rare event. We recommend to realize a thrombophilia screening in such patients. We also support varicella vaccination of children identified as having constitutional prothrombotic disorders like FVL mutation.