Background:Acinetobacter baumannii, is an emerging nosocomial multidrug resistance pathogen with the rapid spread of clones being reported in health-care settings and hospitals worldwide. Carbapenem resistance in this bacterium has been attributed to D OXA β-lactamases with OXA-51-like β-lactamase, being present in all A. baumannii isolate. The present study looks into the antibiotics susceptibility and molecular characterization of clinical A. baumannii isolates from Intensive Care Unit (ICU) samples in Al-Hofuf, South-eastern region of Saudi Arabia.Materials and Methods:Eleven strains of ICU A. baumanni i isolates were used for the investigation. Bacteria isolation was by basic microbiological techniques. Organisms identification and antibiogram susceptibility testing was by the BioMerieux VITEK 2 compact automated system (BioMerieux, Marcy I'Etoile France), according to the manufacturers guidelines. Confirmation of A. baumannii was by the presence of the OX-51 gene, also, carbapenemase encoding resistant genesblaOXA-23, blaOXA-40, and blaOXA-51, were analyzed using multiplex PCR. The Student's t test was used to analyze the obtained data for between group comparisons with statistically significance level set at P < 0.05.Results:Eight of the isolates were confirmed to be A. baumannii. Five of which were resistant to the carbapenems against which they had been tested. One isolate was resistant to tigecycline, whereas three tested intermediate to the drug. OXA-23 was detected in isolates 1, 4, 5, 6, and 7.Conclusion:It can, therefore, be concluded that the probable predominate carbapenems resistant genes in ICU isolates from the present investigation, are those associated with OXA-23.

Antimicrobial resistance by bacteria isolates continues to receive attention globally. This investigation looks into the antibiotic susceptibility pattern of Gram negative bacteria isolated from intensive care unit patients in Al-Ahsa, KSA. Bacteria samples were classified based on the CDC criteria for the definition of ICU infections. Gram negative bacteria had been isolated on MacConkey agar using basic bacteriological technique. Identification and antimicrobial susceptibility was carried out using the GN cards of the Vitek 2 compact system. The results showed non-ESBL producing Klebsiella pneumoniae to be the most frequently encountered, isolated from 21% (n=23) of the patients. Other isolates were ESBL producing Escherichia coli (9.47%) and K. pneumoniae (3.77%), E. coli (15.09%), Pseudomonas aeruginosa (10.38%), Proteus mirabilis (9.43%), Acinetobacter baumannii (8.5%), and Carbapenem resistant K. pneumoniae amongst others. Resistance to five antibiotic groups was seen in A. baumannii, Enterobacter, E. coli, K. pneumoniae ESBL K. pneumoniae, non ESBL K. pneumoniae and P. aeruginosa. The association between bacteria resistance to antibiotic groups was statistically significant with a p-value of 0.00001. The encountered isolates showed both multi-drug resistance as well as extensive drug resistance against the tested drug. This information is being provided for Al-Ahsa and would be important for regional surveillance.