Pregledni rad

Mechanisms of carbapenem resistance in Acinetobacter baumannii

Ivana Goić-Barišić ; Odjel za mikrobiologiju i parazitologiju, KBC Split, Splt, Hrvatska

Sažetak

Organisms of the genus Acinetobacter are ubiquitous and widely distributed in soil and water. They are frequently present on human skin and mucous membranes and are able to survive for long periods on dry and humid surfaces. Acinetobacter baumannii is an opportunistic pathogen that is mostly involved in nosocomial infections in immunocompromised patients. Until the 1970s, most isolates were susceptible to a wide range of antibiotics. Carbapenem resistance results from production of metallo-β-lactamases, carbapenem hydrolyzing oxacillinases, loss of outer membrane proteins, efflux and often combined mechanisms of resistance. These resistance mechanisms pose a serious therapeutic threat, since carbapenems are frequently used to treat otherwise resistant A. baumannii infections. Carbapenemases found in Acinetobacter belong to molecular class D (OXA enzymes) or class B (metalloenzymes of IMP- and VIM-type or SIM-1). The OXA carbapenemases are divided into four phylogenetic subgroups: acquired enzymes OXA-23-like, OXA-40-like and OXA-58-like and OXA-51-like enzymes that are intrinsic to A. baumannii. OXA-51-like enzymes are normally expressed at low levels but can be over expressed as consequence of the insertion of an ISAba1 sequence upstream of their genes. Recently an increase in the prevalence of carbapenem resistant Acinetobacter baumannii isolates was observed in few medical centers in Croatia. The investigation of the background of carbapenem resistance in relevant clinical isolates of A. baumannii from Split University Hospital was performed during last years and sixteen different strains of carbapenem resistant A. baumannii were included in ARPAC project (Antibiotic Resistance, Prevention and Control). The molecular typing by random amplified polymorphic DNAanalysis (RAPD), followed by pulsed-field gel electrophoresis (PFGE) belonged isolates to the same PFGE type as a part of sequence group 2 (European 'clone I' lineage).

Ključne riječi

A. baumannii; resistance; carbapenems

Hrčak ID:

50625

URI

https://hrcak.srce.hr/50625

Datum izdavanja:

4.12.2009.

Podaci na drugim jezicima: hrvatski

Posjeta: 2.871 *