First description of OXA-48-producing Escherichia coli and the pandemic clone ST131 from patients hospitalised at a military hospital in Algeria

The aim of the study was to assess the frequency and diversity of carbapenemases and extended-spectrum beta-lactamases (ESBL) produced by Escherichia coli isolates from patients hospitalised in the Regional Military Hospital of Constantine (Algeria). E. coli isolates were collected over a 2-year period from patients presenting E. coli infections. Strains with reduced susceptibility to ertapenem and/or positive for ESBL were characterised with regard to antibiotic resistance, bla genes, phylogenetic groups, O25 serotyping, quinolone resistance, repetitive sequence-based polymerase chain reaction (rep-PCR) profiles and multi-locus sequence typing (MLST). Of the 448 isolated E. coli, 94 (20.9 %) were multidrug-resistant. One of them (1.1 %) produced a bla (OXA-48) and was identified as a B1 ST5 strain. The transposon bearing this gene was Tn1999.2. This strain was isolated from a patient coming from a border province with Tunisia, where this carbapenemase is endemic. In addition, 84 (18.8 %) isolates among them produced an ESBL with predominance (97.6 %) of bla (CTX-M-15), which was coupled with qnr genes in 10.9 %. ESBL-producing strains were mainly detected in phylogroups D and A. They displayed 20 rep-PCR profiles and all the clonally related isolates were of the same sequence type (ST). Ten strains (9.4 %) belonged to the pandemic clone ST131. This study describes for the first time the presence of OXA-48-producing E. coli and the emergence of the intercontinental ST131 bla (CTX-15)-producing E. coli strains in Algeria.