Prevalence of carbapenemase genes blaOXA-51 and blaOXA23 in multi-drug resistance Acinetobacter baumannii isolated from hospital environment

ABSTRACT

   A. baumannii is a multidrug-resistant bacterium that poses a global medical danger because of its propensity to survive in hospital environments and to cause nosocomial outbreaks. Three hundred and fifty environmental and clinical samples collected from Al-Diwaniyah Teaching Hospital and burns center in Al-Diwaniyah city, Iraq were streaked on MacConkey agar. 46.86% (164/350) of samples were resulted in positive bacterial cultivation which included 16.86% (59/350) lactose non fermenting isolates and 30% (105/350) lactose fermenting isolates, where’s 53.14% (186/350) of samples did not show growth. Lactose non fermenting isolates were selected for isolation of Acintobacter based on colony morphology on macConkey agar and nutrient agar, Gram stain, catalase and oxidase test, and confirmatory identification later as A. baumannii depending on morphological properties on HiCrome™ Acinetobacter agar supplemented with selective supplement (FD271). 6% (21\350) of A. baumannii isolates were recovered from environmental and clinical swabs which included 6% (12/200) of A. baumannii isolates recovered from environmental swabs distributed as following: Patients' beds 15% (6/40), medical devise 5.71% (2/35), waste containers 4% (1/25), summary B tables surface 4% (1/25), hands of medical workers 5% (1/20), and sinks 6.66% (1/15). And 6% (9/150) of A. baumannii isolates recovered from clinical swabs including: Burn 7.36% (7/95) and wound 3.63% (2/55). Antibiotic's resistance against 17 antibiotics of different groups using disk diffusion method showed resistance percentage to piperacillin 95.23 % (20/21), piperacillin tazobactam 33.33%(7/21), ticarcillin clavulante 61.9%(13/21), ceftazidime and cefotaxime100%(21/21), cefepime 90.47% (19/21), imipenem 28.57% (6/21), meropenem 38.09% (8/21), gentamicin 19.04% (4/21), amikacin 57.14% (12/21), doxycycline 4.76% (1/21), tetracycline 23.8% (5/21), ciprofloxain 9.52%(2/21), levofloxain 0%(0/21), gatifloxain 9.52%(2/21), trimethoprim-sulfamethoxazole 28.57 %(6/21), Colistin  23.80%(5/21). Where’s colistin resistance percentage by agar dilution MIC method was 14.28% (3/21) with MIC value 8 µg/ml. nineteen (19) different environmental and clinical A. baumannii isolates was selected for detection of carbapenems genes bla_OXA-51 and bla_OXA23 by PCR technique, the results showed the percentage bla_OXA-51 gene was 100% (19/19) and bla_OXA-23 gene 36.84% (7/19).