Determining a pattern for antibiotic resistance in clinical isolations of pseudomonas aeruginosa

Background: Pseudomonas aeruginosa is an opportunistic pathogen and one of the important factors of hospital infection. It causes many issues such as urinary tract infections, respiratory infection in cystic fibrosis patients, and wound infection in burn patients, septicemia and meningitis. Antibiotic resistance through various mechanisms is one of the challenges for the treatment of pseudomonad-caused infections. According to the inherent and acquired capacity of this bacterium in creating resistance against the antimicrobial factors, it is very important to identify a pattern for its antibiotic resistance. The aim of this study was to deliberate the frequency of pattern antibiotic resistance of pseudomonas aeruginosa strains. Methods: In this cross-sectional study, 200 pseudomonas aeruginosa isolations (from 86 males and 114 females) were collected from different samples such as urine, blood, wound, catheter and other samples from teaching hospitals in Zahedan City during nine-month period in 2017. After conducting biochemical tests and confirming bacterium type, based on Clinical Laboratory Standards Institute (CLSI), the antibiotic resistance of strains for 10 antibiotics was determined using disk diffusion method. In addition, the minimum inhibitory concentration of three antibiotics such as imipenem, piperacillin/tazobactam and ceftazidime were determined through E-test. The Chi-square test was used for statistical analysis through the SPSS software, version 16 (IBM SPSS, Armonk, NY, USA). Results: Out of 200 pseudomonas aeruginosa isolations (from 86 males and 114 females), the maximum resistance was related to ciprofloxacin (37%) and gentamicin (28.5%). The minimum resistance was related to piperacillin/tazobactam (6.5%) and ceftazidime (6%). The highest separated strain was from urine sample (54%), blood sample (23.5%) and wound sample (10.5%). Additionally all strains were sensitive to colistin. In this study, the percentage of multidrug-resistance (MDR) and extensively drug-resistant (XDR) strains were investigated, which were 13% and 5.5%, respectively. Conclusion: In this study, pseudomonas aeruginosa isolates had the lowest resistance to ceftazidime which this antibiotic could be the main treatment option. The high prevalence of MDR strains is a serious warning.