Background: Acinetobacter baumannii (A. baumannii) has emerged as a healthcare-associated pathogen worldwide. Several epidemiological studies have reported the occurrence of multi-drug resistant A. baumannii infections in different regions of the world. The spread of carbapenem-resistant A. baumannii is of a global concern.
Objectives:  This work was carried out to detect carbapenem-resistant A. baumannii in Surgical Departments and intensive care units (ICUs), Al-Azhar University hospital, New Damietta. It was also aimed to determine the occurrence of bla OXA -51-like and bla OXA-23 like genes among the isolated strains.
Patients and methods: The current study was conducted on 500 patients attending the Surgical Departments and ICUs during the period between May 2016 and September 2018. The choice of samples differs according to the clinical manifestations.
     The isolates were obtained from various clinical specimens, i.e. sputum, endotracheal aspirate   (ETA), pus, urine and blood samples. All clinical specimens were collected under complete aseptic conditions. The clinical specimens were traced to the species level using API 20NE system followed by an assesment of the different phenotypic assays for detection of carbapenemase production using multiplex polymerase chain reaction (PCR).
Results: Post-operative infections were detected in 217 (43.4%) out of 500 of patients. A. baumannii was considered the third common isolated Gram-negative organisms (27, 12.3 %). A. baumannii isolates were predominant in ICUs (14, 51.9%). Carbapenemase production was detected in A. baumannii isolates using the modified Carbapenem Inactivation Method (mCIM), the modified Hodge test (MHT)  and the Carba NP test. Using multiplex PCR analysis, most isolates (12; 44.4%) carried bla OXA-51-like gene, followed by ten (37%) isolates that carried both bla OXA-51-like and bla OXA-23-like genes. Only one (3.7%) isolate carried bla OXA-23-like gene.
Conclusion: The current study suggested that A. baumannii is one of the most commonly detected isolates in our hospital.  The mCIM is the most useful phenotypic method for detection of carbapenemase production. Detection of carbapenem resistance genes is alarming a serious healthcare problem in our hospital.