assessment of antibiotic resistance pattern in acinetobacter bumannii carrying bla oxa type genes isolated from hospitalized patients

abstract please cite this article as: goudarzi h, douraghi m, ghalavand z, goudarzi m. assessment of antibiotic resistance pattern in acinetobacter baumannii carrying bla oxa type genes isolated from hospitalized patients. novel biomed 2013;1(2):54-61. introduction: acinetobacter baumannii is a gram-negative coccobacillus and one of the most opportunistic pathogens responsible for serious infections in hospitalized patients. methods: during a 12 month study, 221 clinical isolates and 22 environmental acinetobacter baumannii isolates were collected. in vitro susceptibility of acinetobacter baumannii isolates to 13 antimicrobial agents amikacin; cefepime; ceftazidime; ciprofloxacin; meropenem; piperacillin/tazobactam; sulfamethoxazole/ trimethoprim; imipenem; tigecycline; colistin; gentamycin; ceftriaxone; levofloxacin was performed by the disk diffusion method and minimum inhibitory concentration(mics) of imipenem; levofloxacin and cefepime.was done by the e-test according to clinical and laboratory standards institute (clsi) criteria. bla oxa-23 , bla oxa-24 , bla oxa-58 , bla oxa-51 genes were detected by polymerase chain reaction and sequencing. results: the result of antimicrobial susceptibility test of clinical isolates by the disk diffusion method revealed that that all strains of acinetobacter baumannii were resistant to piperacillin/tazobactam. the rates of resistance to the majority of antibiotics tested varied between 69% and 100 %, with the exception of tigecycline and colistin. of 221 isolates tested 99(44.8%) were xdr. all strains carry a bla oxa-51 -like gene. bla oxa-23 gene was the most prevalence among bla oxa-types . conclusion : colistin and tigecycline can be effective drugs for treatment of acinetobacter baumannii infections. continuous surveillance for acinetobacter baumannii multidrug-resistant strains is necessary to prevent the further spread of resistant isolates.