title: Carbapenemases and extended-spectrum β-lactamases producing Enterobacteriaceae isolated from Tunisian and Libyan hospitals.
abstract: BACKGROUND
  The aim of the study was to investigate the prevalence of extended-spectrum β-lactamase (ESBL) and carbapenemase production among clinical isolates of Enterobacteriaceae recovered from Tunisian and Libyan hospitals.
  
  
  METHODS
  Bacterial isolates were recovered from patients in intensive care units and identified by biochemical tests and MALDI-TOF. Antibiotic susceptibility testing was performed by disk diffusion and the E-test method. ESBL and carbapenemase activities were detected using standard microbiological tests. Antibiotic resistance-encoding genes were screened by PCR and sequencing. Clonal relationships between Klebsiella pneumoniae strains were carried out using multi-locus sequence typing (MLST).
  
  
  RESULTS
  A total of 87 isolates were characterized, with 51 and 36, respectively, identified as E. coli and K. pneumoniae. Overall the resistance prevalence was high for aminoglycosides (> 60%), fluoroquinolones (> 80%), and extended-spectrum cephalosporins (> 94%), and was low for imipenem (11.4%). Among this collection, 58 strains (66.6%) were ESBL producers and 10 K. pneumoniae strains (11.4%) were carbapenemase producers. The antibiotic resistance-encoding genes detected were blaCTX-M-15 (51.7%), blaTEM-1 (35.6%), several variants of blaSHV (21.8%), and blaOXA-48 (11.4%). The MLST typing of K. pneumoniae isolates revealed the presence of multiple clones and three novel sequence types. Also, close relationships between the OXA-48-producing strains from Tunisia and Libya were demonstrated.
  
  
  CONCLUSIONS
  This study is the first paper describing the emergence of carbapenemase- and ESBL-producing Enterobacteriaceae, sensitive to colistin, isolated in Tunisia and Libya. Active surveillance and testing for susceptibility to colistin should be implementing because resistance to colistin, mainly in Klebsiella, has been recently reported worldwide.
authors.affiliation: Faculté de Médecine et de Pharmacie, Aix-Marseille-Université, Marseille, France. najla.mathlouthi@yahoo.fr.
authors.forename: Najla
authors.initials: N
authors.lastname: Mathlouthi
authors.forename: Charbel
authors.initials: C
authors.lastname: Al-Bayssari
authors.forename: Allaaeddin
authors.initials: A
authors.lastname: El Salabi
authors.forename: Sofiane
authors.initials: S
authors.lastname: Bakour
authors.forename: Salha
authors.initials: S
authors.lastname: Ben Gwierif
authors.forename: Abdulaziz A
authors.initials: AA
authors.lastname: Zorgani
authors.forename: Yahia
authors.initials: Y
authors.lastname: Jridi
authors.forename: Karim
authors.initials: K
authors.lastname: Ben Slama
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Rolain
authors.forename: Chedly
authors.initials: C
authors.lastname: Chouchani
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D015373:Bacterial Typing Techniques; D003091:Colistin / Q000494:pharmacology; D003428:Cross Infection / Q000453:epidemiology / Q000382:microbiology*; D024881:Drug Resistance, Bacterial; D004756:Enterobacteriaceae Infections / Q000453:epidemiology / Q000382:microbiology*; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification*; D005838:Genotype; D006761:Hospitals; D006801:Humans; D007362:Intensive Care Units; D007711:Klebsiella pneumoniae / Q000145:classification / Q000201:enzymology* / Q000235:genetics / Q000302:isolation & purification*; D008002:Libya / Q000453:epidemiology; D008826:Microbial Sensitivity Tests; D058885:Multilocus Sequence Typing; D016133:Polymerase Chain Reaction; D015995:Prevalence; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D014416:Tunisia / Q000453:epidemiology; D001618:beta-Lactamases / Q000235:genetics / Q000378:metabolism*
chemical_list: D000900:Anti-Bacterial Agents; D001618:beta-Lactamases; D003091:Colistin