title: Epidemiology of carbapenem non-susceptible Pseudomonas aeruginosa isolates in Eastern Algeria.
abstract: BACKGROUND
  Carbapenem resistance among Pseudomonas aeruginosa has become a serious life-threatening problem due to the limited therapeutic options. In this study, we investigated the prevalence and the molecular epidemiology of carbapenem resistant Pseudomonas aeruginosa (CRPA) isolated from three hospitals in Annaba city, Algeria.
  
  
  METHODS
  During the study period (January, 2012 to December, 2013), all patients infected by P. aeruginosa were considered as the potential study population. Antibiotic susceptibility testing was performed as recommended by the CLSI. Screening of carbapenemase producer isolates was performed by using imipenem-EDTA double-disk synergy test and modified Hodge test. CRPA isolates were tested for the presence of genes encoding β-lactamases, plasmid mediated quinolone resistance, aminoglycoside resistance and class 1 integrons were investigated by PCR and sequencing. The clonal relatedness among CRPA isolates was analyzed by pulsed-field gel electrophoresis method. The clinical data were collected to identify risk factors for CRPA carriage of P. aeruginosa infection.
  
  
  RESULTS
  The overall prevalence of CRPA was 18.75 %. The risk factors for carrying CRPA were the length of hospital stay (p = 0.04), co-infections with Staphylococcus aureus (p = 0.01), and the use of urinary catheter (p = 0.03). The in-hospital mortality rate among case patients was 13.33 % compared with 1.53 % for control patients (p = 0.09). All CRPA isolates were multidrug resistance and the most effective antibiotic against CRPA isolates was amikacin and colistin. PFGE revealed an epidemic clonal dissemination of CRPA isolates. None of CRPA isolated were found to be carbapenemase-producers. The bla PSE-1 and aac(3)-II gene was detected in two and five strains respectively. The class1 integrons were detected in 2 isolates with the presence of aadA7 gene cassette in these integrons.
  
  
  CONCLUSIONS
  The endemic clonal dissemination and multi-drug resistance of CRPA isolates in our institution is highly alarming. Strict measure will be required to control the further spread of these pathogens in hospital setting.
authors.affiliation: Department of Biology, Biochemstry and Applied Microbiology Laboratory, Badji Mokhtar Faculty of sciences, Annaba University, Box 12, Sidi Amar, 23000 Annaba, Algeria.
authors.forename: Samah
authors.initials: S
authors.lastname: Meradji
authors.affiliation: Molecular Bacteriology Laboratory, Pasteur Institute of Morocco, 1, Place Louis Pasteur, 20360 Casablanca,, Morocco ; Microbiology Laboratory, Faculty of Medicine and Pharmacy, 1 Street Hospital, 20360 Casablanca, Morocco.
authors.forename: Abouddihaj
authors.initials: A
authors.lastname: Barguigua
authors.affiliation: Microbiology Laboratory, Faculty of Medicine and Pharmacy, 1 Street Hospital, 20360 Casablanca, Morocco.
authors.forename: Khalid
authors.initials: K
authors.lastname: Zerouali
authors.affiliation: Microbiology Laboratory, University Hospital Ibn Rochd, 23000 Annaba, Algeria.
authors.forename: Dekhil
authors.initials: D
authors.lastname: Mazouz
authors.affiliation: Department of Biology, Biochemstry and Applied Microbiology Laboratory, Badji Mokhtar Faculty of sciences, Annaba University, Box 12, Sidi Amar, 23000 Annaba, Algeria.
authors.forename: Houria
authors.initials: H
authors.lastname: Chettibi
authors.affiliation: Molecular Bacteriology Laboratory, Pasteur Institute of Morocco, 1, Place Louis Pasteur, 20360 Casablanca,, Morocco.
authors.forename: Naima
authors.initials: N
authors.lastname: Elmdaghri
authors.affiliation: Molecular Bacteriology Laboratory, Pasteur Institute of Morocco, 1, Place Louis Pasteur, 20360 Casablanca,, Morocco.
authors.forename: Mohammed
authors.initials: M
authors.lastname: Timinouni
keywords: Carbapenem resistance; Prevalence; Pseudomonas aeruginosa; Risk factors