Study of aerobic and anaerobic bacterial profile of nosocomial infections and their antibiotic resistance in a referral center, Southwest Iran: A three year cross-sectional study.

Background: The drug resistance is expected to be the most important challenge in infection control in Iran, where there is no local report or standard drug resistance monitoring system. Therefore, this study aimed to investigate the aerobic and anaerobic bacterial profile of nosocomial infections and their antibiotic resistance in Ahvaz, southwest Iran.

Methodology: The gram-positive and gram-negative bacteria were identified on the basis of conventional culture and biochemical tests. The antibiotic resistance of the bacterial isolates against antibiotics was determined by the disk diffusion method.

Results: Among total 1156 collected positive samples, E. coli and coagulase-negative staphylococci (CoNS) were the most frequent pathogenic gram negative bacteria (GNB) and gram positive bacteria (GPB) respectively. Drug susceptibility testing revealed that among GNB, P. aeruginosa was 100% resistant to amikacin, cefepime, ciprofloxacin and tetracycline. In the case of E. coli, the resistance rate was (98%) for trimethoprim sulfamethoxazole and cefepime. For GPB, S. aureus showed the highest resistance rates to amikacin (100%) and clindamycin (100%). In addition, CoNS strains showed a high level of resistance to doxycycline (100%), erythromycin (100%) and cefoxitin (97%). In Bacteroeides fragilis isolates, the highest resistance rate belonged to clindamycin (72%), and Clostridium perfringens strains showed high level of resistance to penicillin (46%).

Conclusion: The results highlighted that there are distinct factors leading to antimicrobial resistance in Ahvaz, southwest Iran. The primary contributors to the resistance development, include poor surveillance of drug-resistant infections, poor quality of available antibiotics, clinical misuse, and the ease of access to antibiotics. Moreover, similar factors such as self-medication and the lack of regulation on medication imports play a role in antibiotic resistance in the region.