title: β-Lactamases Encoded by blaCTX-M Group I Genes as Determinants of Resistance of Esbl-Positive Enterobacteriaceae in European Soldiers in Tropical Mali.
abstract: ESBL (extended-spectrum-β-lactamase)-positive Enterobacteriaceae, which colonized European soldiers in tropical Western African Mali, were subjected to a molecular assessment of their resistance determinants. By doing so, a better insight into the locally endemic pattern of ESBL-associated β-lactamase genes was aspired. From a previous study on diarrhea in European soldiers on deployment in tropical Mali, 15 ESBL-positive Escherichia coli with demonstrated high clonal diversity and one positive Klebsiella pneumoniae were assessed. Polymerase chain reactions (PCRs) for blaTEM and blaSHV β-lactamase genes with subsequent sequencing for the discrimination of ESBL- and non-ESBL variants were performed, followed by four group-specific PCRs for blaCTX-M genes. Non-ESBL-associated blaTEM-1 was identified in six out of 15 (40%) E. coli strains, while 100% of the assessed strains were positive for group I blaCTX-M . Considering the known clonal diversity of the assessed strains, the striking restriction to one group of blaCTX-M genes accounting for the ESBL phenotypes of the isolates suggests little genetic exchange in the local setting. Under such circumstances of restricted numbers of locally endemic target genes, PCR-based screening approaches for ESBL colonization might be promising.
authors.affiliation: Department of Tropical Medicine at the Bernhard Nocht Institute, German Armed Forces Hospital of Hamburg , Germany.
authors.forename: Ralf Matthias
authors.initials: RM
authors.lastname: Hagen
authors.affiliation: Department of Tropical Medicine at the Bernhard Nocht Institute, German Armed Forces Hospital of Hamburg , Germany.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Hinz
authors.affiliation: Department of Tropical Medicine at the Bernhard Nocht Institute, German Armed Forces Hospital of Hamburg , Germany ; Institute for Microbiology and Immunology, University Medicine Rostock , Germany.
authors.forename: Hagen
authors.initials: H
authors.lastname: Frickmann
keywords: Enterobacteriaceae; Mali; colonization; deployment; extended-spectrum β-lactamase; resistance