ABSTRACT
Ventilator associated pneumonia [VAP] is one of the serious complications of ventilatory support, occurring in ICUs. The aim of this study was to determine various risk factors associated with the acquisition of Acinetobacter infection and its antimicrobial susceptibility pattern. This cross-sectional study was performed in the ICUs of Rasoul-e-Akram Hospital in Tehran, Iran during the year 2011. A total of 51 endobronchial aspirates from intubated patients who had been clinically diagnosed to have VAP were studied bacteriologically. The in vitro susceptibility was determined by disk-diffusion and broth microdilution MIC methods. Out of 51 patients with VAP, 35 [66.66%] had positive cultures for Acinetobacter species. In vitro susceptibility test revealed that a high percentage of isolates were resistant to imipenem, piperacillin-tazobactam, third generation cephalosporines, and aminoglycosides. The antimicrobial resistance of gram negative bacteria, particularly Acinetobacter species, is increasing and preventive measures need to be taken as a matter of urgency.
ABSTRACT
Multi-drug resistant strains of Acinetobacter spp. have created therapeutic problems worldwide. The objective of this study was to detect integrons in Acinetobacter spp. isolates from Ventilator-Associated Pneumonia patients using PCR method. A total 51 Bronchoalveolar lavage samples were obtained from patients in ICU and examined for Acinetobacter spp. infection by biochemical and PCR methods using blaOXA51-like primers. Antimicrobial susceptibility testing was performed using disk diffusion and MIC methods. Among 51 patients with VAP [62.7% males, 35.2% females, mean age 53 year], 50 [98%] were positive, with a high prevalence of gram-negative bacteria, mainly Acinetobacter spp. [70%], from which A. baumani was detected in 34 [68%] and A. lwoffii in 1 [2%] of isolates. More than 90% of isolates were resistant to imipenem, piperacillin+tazobactam, third generation cephalosporins and gentamicin, while the most effective antibiotic was colistin [100%]. The correlation coefficient between disk diffusion and MIC was 0.808 [p = 0.001]. Three Acinetobacter isolates [8%] harbored integrase /gene but none of isolates contained Class II or III integrons. The results showed that colistin was an effective antibiotic and can be used for treatment of patients in ICU. Due to the high number of MDR isolates lacking Integrons it can be concluded that although class I integrons are important among clinical isolates of A. baumannii, they have no significant role in dissemination of antibiotic resistance genes in Rasoul Akram Hospital in Tehran, Iran. The presence of IntI in A. Iwoffii may be related to transfer of integron to A. baumannii which can be considered as an important threat for hospitalized patients