Background: Pseudomonas aeruginosa is a Gram-negative opportunistic pathogen. It is a ubiquitous bacterium that is found and isolated from various environments including plants, animals, soil and humans. This bacterium accounts for 10-15% of the nosocomial infections worldwide and is considered the third most-common organism associated with hospital-acquired infections such as urinary catheter-associated infections, ventilator-associated pneumonia as well as blood, burn and wound infections, particularly involving wound infections in immunocompromised patients. Methodology: One hundred and sixty samples were collected from clinical specimens from the Babylon hospitals during the period of July-2019 to November-2019. These samples included 40 injury samples, 55 diabete-infected foot samples and 65 burn samples. Blood agar (Himedia) and MacConkey agar (Himedia) were used to isolated this bacterium, using the streaking technique and identified depending on their morphological properties (cultural and microscopical), biochemical tests, and then confirmed by PCR-sequencing for universal 16S rRNA gene. An antibiotic susceptibility tests were performed using clinical and laboratory standards institute guideline (2019). Results: The results revealed that only 30 isolates were P. aeruginosa. The highest resistant percentages toward the antibiotics were found with ceftazidime and cefotaxime (96.7 %), while the lowest resistant percentages were found with colistin and polymyxin B (40 %). The ability of these isolates to produce OXA β-lactamase was investigated using PCR, it was found that 26.6% of the isolates belong to OXA-I, 40% of the isolates belong to OXA-III and no one of these isolates belong to OXA-II. Conclusion: The rates of OXA-type β-lactamases producing P. aeruginosa isolates from the clinical specimens were notable, therefore, the management and the treatment strategies should be revised and the proper use of the infection-control measures is needed to reduce the spread of the resistant genes in the isolates of P. aeruginosa.

• Aghazadeh, M., Samadi Kafil, H., Ghotaslou, R., Asgharzadeh, M., Moghadami, M., Akhi, M. T., ... & Shokrian, S. (2016). Prevalence of oxacillinase groups i, ii and iii in Pseudomonas aeruginosa isolates by polymerase chain reaction and genotyping by ERIC-PCR methods. Jundishapur Journal of Microbiology, 1-6.
• Alam, A. N., Sarvari, J., Motamedifar, M., Khoshkharam, H., Yousefi, M., Moniri, R., & Bazargani, A. (2018). The occurrence of blaTEM, blaSHV and blaOXA genotypes in Extended-Spectrum β-Lactamase (ESBL)-producing Pseudomonas aeruginosa strains in Southwest of Iran. Gene Reports, 13, 19-23.
• Ali, A. M., Al-Kenanei, K. A., & Bdaiwi, Q. O. (2020). Molecular study of some virulence genes of Pseudomonas aeruginosa isolated from different infections in hospitals of Baghdad. Reviews in Medical Microbiology, 31(1), 26-41.
• Aubert, D., Poirel, L., Chevalier, J., Leotard, S., Pages, J. M., & Nordmann, P. (2001). Oxacillinase-mediated resistance to cefepime and susceptibility to ceftazidime in Pseudomonas aeruginosa. Antimicrobial agents and chemotherapy, 45(6), 1615-1620.
• Bert, F., Branger, C., & Lambert-Zechovsky, N. (2002). Identification of PSE and OXA β-lactamase genes in Pseudomonas aeruginosa using PCR–restriction fragment length polymorphism. Journal of Antimicrobial Chemotherapy, 50(1), 11-18.
• Bonomo, R. A. (2017). β-Lactamases: a focus on current challenges. Cold Spring Harbor perspectives in medicine, 7(1), a025239.
• Bush, K., & Bradford, P. A. (2020). Epidemiology of β-Lactamase-producing pathogens. Clinical Microbiology Reviews, 33(2).
• Bush, K., & Jacoby, G. A. (2010). Updated functional classification of β-lactamases. Antimicrobial agents and chemotherapy, 54(3), 969-976.
• El-Shouny, W. A., Ali, S. S., Sun, J., Samy, S. M., & Ali, A. (2018). Drug resistance profile and molecular characterization of extended spectrum beta-lactamase (ESβL)-producing Pseudomonas aeruginosa isolated from burn wound infections. Essential oils and their potential for utilization. Microbial pathogenesis, 116, 301-312.
• Gajamer, V. R., Bhattacharjee, A., Paul, D., Ingti, B., Sarkar, A., Kapil, J., ... & Tiwari, H. K. (2020). High prevalence of carbapenemase, AmpC β-lactamase and aminoglycoside resistance genes in extended-spectrum β-lactamase-positive uropathogens from Northern India. Journal of Global Antimicrobial Resistance, 20, 197-203.
• Hasan, A. S. (2019). Antibiogram of Pseudomonas aeruginosa Isolated from Burn& Wound Infections Among Inpatients and Outpatients Attending to Ramadi Teaching Hospital in Ramadi, Iraq. Egyptian Academic Journal of Biological Sciences, G. Microbiology, 11(1), 13-22.
• Hocquet, D., Plésiat, P., Dehecq, B., Mariotte, P., Talon, D., & Bertrand, X. (2010). Nationwide investigation of extended-spectrum β-lactamases, metallo-β-lactamases, and extended-spectrum oxacillinases produced by ceftazidime-resistant Pseudomonas aeruginosa strains in France. Antimicrobial agents and chemotherapy, 54(8), 3512-3515.
• J Wolter, D., & D Lister, P. (2013). Mechanisms of β-lactam resistance among Pseudomonas aeruginosa. Current pharmaceutical design, 19(2), 209-222.
• Jawetz, E., Melnik, J.L.; Adelberg, E.A.; Brook, G.F.; Butel, J.S. & Morse, S.A.(2019). Medical Microbiology 47th ed. Appleton and Lang New York. Connecticut. PP.759-783.
• Jia, X., Ma, W., He, J., Tian, X., Liu, H., Zou, H., & Cheng, S. (2020). Heteroresistance to cefepime in Pseudomonas aeruginosa bacteraemia. International journal of antimicrobial agents, 105832.
• Lafi, S. A., & Al-Ani, R. M. (2020). Study of Aerobic Agents in Chronic Suppurative Otitis Media and their Sensitivity to Antibiotics in Ramadi City. Egyptian Academic Journal of Biological Sciences, G. Microbiology, 12(1), 9-18.
• Lin, S. P., Liu, M. F., Lin, C. F., & Shi, Z. Y. (2012). Phenotypic detection and polymerase chain reaction screening of extended-spectrum β-lactamases produced by Pseudomonas aeruginosa isolates. Journal of Microbiology, Immunology and Infection, 45(3), 200-207.
• Loy, A., Lehner, A., Lee, N., Adamczyk, J., Meier, H., Ernst, J., ... & Wagner, M. (2002). Oligonucleotide microarray for 16S rRNA gene-based detection of all recognized lineages of sulfate-reducing prokaryotes in the environment. Applied and Environmental Microbiology, 68(10), 5064-5081.
• MacFaddin, J. F. (2000). Biochemical Tests for Identification of Medical Bacteria, Williams and Wilkins. Philadelphia, PA, 113.
• Mitra, S., Basu, S., Rath, S., & Sahu, S. K. (2020). Colistin resistance in Gram-negative ocular infections: prevalence, clinical outcome and antibiotic susceptibility patterns. International Ophthalmology, 1-11.
• Nasser, M., Gayen, S., & Kharat, A. S. (2020). Prevalence of the β-lactamase and Antibiotic Resistant Pseudomonas aeruginosa in the Arab Region. Journal of Global Antimicrobial Resistance.
• Naveed, M., Chaudhry, Z., Bukhari, S. A., Meer, B., & Ashraf, H. (2020). Antibiotics resistance mechanism. In Antibiotics and Antimicrobial Resistance Genes in the Environment (pp. 292-312). Elsevier.
• Obinna-Echem, P. C., & Torporo, C. N. (2018). Physico-Chemical and Sensory Quality of Tigernut (Cyperus Esculentus)–Coconut (Cocos Nucifera) Milk Drink. Agriculture and Food Sciences Research, 5(1), 23-29.
• Okoche, D., Asiimwe, B. B., Katabazi, F. A., Kato, L., & Najjuka, C. F. (2015). Prevalence and characterization of carbapenem-resistant Enterobacteriaceae isolated from Mulago National Referral Hospital, Uganda. PLoS One, 10(8), e0135745.
• Paramythiotou, E., & Routsi, C. (2016). Association between infections caused by multidrug-resistant gram-negative bacteria and mortality in critically ill patients. World journal of critical care medicine, 5(2), 111.
• Rahman, M., Prasad, K. N., Pathak, A., Pati, B. K., Singh, A., Ovejero, C. M., ... & Gonzalez-Zorn, B. (2015). RmtC and RmtF 16S rRNA methyltransferase in NDM-1–producing Pseudomonas aeruginosa. Emerging infectious diseases, 21(11), 2059.
• Salim, R. M., & Alwan, S. K. (2017). Prevalence of OXA beta-lactamaes of pseudomonas aeruginosa in Al-Diwaniya City. Al-Qadisiyah Journal Of Pure Science, 22(3), 393-405.
• Shokoohizadeh, L., Alizade, H., Namordizadeh, V., & Karmostaji, A. (2020). Tandem repeat analysis for typing of Pseudomonas aeruginosa carrying resistance genes in southern Iran. Reviews in Medical Microbiology, 31(2), 92-98.
• Weinstein, M. P. (Ed.). (2019). Performance standards for antimicrobial susceptibility testing, 29th ed. Clinical and Laboratory Standards Institute.‏
• Zhao, W. H., & Hu, Z. Q. (2010). β-lactamases identified in clinical isolates of Pseudomonas aeruginosa. Critical reviews in microbiology, 36(3), 245-258.

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.