Occurrence of esbl and mbl genes in pseudomonas aeruginosa and acinetobacter baumannii isolated from baghdad, Iraq

A total of Ninety two clinical isolates of Acinetobacter baumannii and Pseudomonas aeruginosa isolated from various infections were tested for extended spectrum β- lactamase (ESBL) and metallo-β-lactamase (MBL) production by double disc synergy and disc potentiating tests. The prevalence of ESBLs was 35.2% and 25% of A.baumannii and P.aeruginosa respectively, and 41.1% of A. baumannii and 20% of P.aeruginosa isolates were produced MBLs. The susceptibility to different antibiotics was evaluated by disk diffusion method and MICs of cefixime, imipenem, cefotaxime and ceftazidime were determined. PCR was performed for detection of bla TEM, bla SHV, bla CTX-M , bla OXA-1 , bla IMP-1 and bla VIM-2 beta-lactamase genes .The isolates were highly beta- lactam-resistant (MIC ranges of cefixime, imipenem, cefotaxime and ceftazidime were 2 - 512 μg/ml , 4- 512 μg/ml, 32 - >512 μg/ml and 16 - >512 μg/ml respectively) and multidrug-resistant. The results of ESBLs genes detection clarify, that all of ESBLs and MBLs producer isolates of A.baumannii and P.aeruginosa carried bla CTX-M gene, 16.6 % of ESBLs producers and 42.8% of MBLs producers of A.baumannii have carried bla TEM gene, in contrast, neither ESBLs nor MBLs producers of P.aruginosa were carried bla TEM gene. bla IMP-1 type was detected in 42.8 % of A.baumannii. bla VIM-2 didn’t appear in any isolate of ESBLs or MBLs producers.