Pattern of antibiotic resistance in nosocomial infections with Gram-negative bacilli in ICU patients (Tehran, Iran) during the years 2012-2014

Background and Objective: Owing to the new patterns of antibiotic resistance, selection of the appropriate antibiotics for the treatment of nosocomial infections, especially gram-negative bacilli, has become a big challenge. Therefore, the aim of this study was to evaluate the antibiotic resistance of nosocomial infections with Gram-negative bacilli in Iran during the years 2012-2014. Materials and Methods: In this cross-sectional study, samples of the culture of patients with nosocomial infections in various departments of the Shahid Mostafa Khomeini hospital of Tehran were studied over a three-year period. Information on the culture-positive blood, urine, sputum, and exudates in terms of the presence of the most common nosocomial aerobic Gram-negative bacilli (Acinetobacter baumannii, Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae), the type of consumed antibiotics, and an antibiotic susceptibility test was extracted from patient records and recorded in the information forms. Results: The percentage of P. aeruginosa resistance has increased during the study period as compared to the colistin, meropenem, imipenem, gentamicin, and ceftazidime antibiotics. A. baumannii and E. coli bacteria showed the highest resistance, while the maximum susceptibility was observed in this period to ampicillin and colistin. The high resistance of K. pneumoniae was also observed to cefotaxime and ampicillin, but this bacterium had a high susceptibility to colistin and meropenem. Conclusion: The results obtained from the antibiotic resistance of the studied bacteria during the three years of the study demonstrates the increasing prevalence of the resistance of Gram-negative bacteria to common and available antibiotics. This could become a major clinical crisis in the near future.