title: Mechanisms of Carbapenem Resistance in Multidrug-Resistant Clinical Isolates of Pseudomonas aeruginosa from a Croatian Hospital.
abstract: Pseudomonas aeruginosa is an opportunistic pathogen, one of the leading causes of nosocomial infections such as pneumonia, urinary tract infections, and bacteraemia. The bacterial resistance to structurally unrelated antibiotics and its spread within hospitals limits the efficient antimicrobial options and patients' outcome. Carbapenems are important agents for the therapy of infections due to multidrug-resistant (MDR) P. aeruginosa; hence, the development of carbapenem resistance severely hampers effective therapeutic options. The aim of this investigation was to examine mechanisms of carbapenem resistance and genomic diversity in carbapenem-resistant MDR strains of P. aeruginosa, which caused an outbreak among patients in Clinical Hospital Rijeka. Most of the isolates showed decreased expression of porin that is important for the entry of carbapenems (oprD). Overexpression of MexAB-OprM, MexCD-OprJ, and MexEF-OprN efflux systems was observed in many of the isolates. Production of metallo-β-lactamases was not detected. Typing by pulsed-field gel electrophoresis discriminated the isolates into five clusters. The clonal distribution of the strains was related to the location of hospital departments where the isolates were collected, which implies that most of the infections were caused by spread of the epidemic strains within the hospital.
authors.affiliation: 1Department of Microbiology, Faculty of Medicine, University of Rijeka, Rijeka, Croatia.|2Department of Clinical Microbiology, Clinical Hospital Centre Rijeka, Rijeka, Croatia.
authors.forename: Marina
authors.initials: M
authors.lastname: Bubonja-Sonje
authors.affiliation: 1Department of Microbiology, Faculty of Medicine, University of Rijeka, Rijeka, Croatia.
authors.forename: Mihaela
authors.initials: M
authors.lastname: Matovina
authors.affiliation: 2Department of Clinical Microbiology, Clinical Hospital Centre Rijeka, Rijeka, Croatia.
authors.forename: Ivana
authors.initials: I
authors.lastname: Skrobonja
authors.affiliation: 3Department of Microbiology, School of Medicine, University of Zagreb, Zagreb, Croatia.|4Clinical Department for Clinical and Molecular Microbiology, University Hospital Centre Zagreb, Zagreb, Croatia.
authors.forename: Branka
authors.initials: B
authors.lastname: Bedenic
authors.affiliation: 1Department of Microbiology, Faculty of Medicine, University of Rijeka, Rijeka, Croatia.|2Department of Clinical Microbiology, Clinical Hospital Centre Rijeka, Rijeka, Croatia.
authors.forename: Maja
authors.initials: M
authors.lastname: Abram
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics / Q000378:metabolism; D015373:Bacterial Typing Techniques; D015780:Carbapenems / Q000494:pharmacology; D017523:Croatia / Q000453:epidemiology; D003428:Cross Infection / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology; D004196:Disease Outbreaks; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D015964:Gene Expression Regulation, Bacterial; D006761:Hospitals; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism; D010802:Phylogeny; D018272:Porins / Q000235:genetics* / Q000378:metabolism; D011552:Pseudomonas Infections / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology; D011550:Pseudomonas aeruginosa / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D017422:Sequence Analysis, DNA
chemical_list: D000900:Anti-Bacterial Agents; D001425:Bacterial Outer Membrane Proteins; D015780:Carbapenems; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; C118598:MexA protein, Pseudomonas aeruginosa; C118597:MexB protein, Pseudomonas aeruginosa; C470189:MexC protein, Pseudomonas aeruginosa; C121980:MexD protein, Pseudomonas aeruginosa; C470190:OprJ protein, Pseudomonas aeruginosa; C402263:OprM protein, Pseudomonas aeruginosa; C105708:OprN protein, Pseudomonas aeruginosa; D018272:Porins; C077157:OprD protein, Pseudomonas aeruginosa