Assessing the frequency and antibiotic resistance of nosocomial bacterial infections in the intensive care units and general wards

Abstract

Considering the perpetual existence of resistant bacteria in different wards of hospitals, particularly the intensive care unit (ICU), as well as the hindrance they cause against therapy make it necessary to have comprehensive knowledge of these bacteria and their respective pattern of antibiotic resistance in different communities. This study was conducted to determine the pattern of antibiotic resistance for common bacteria in general wards and the intensive care unit of our hospital. This is a cross-sectional, descriptive study conducted from October 2009 through October 2010, in Madaen Hospital, Tehran. Standard sampling was performed for biologic fluids, wounds and devices associated with patients such as nozzle of the suction unit, endotracheal tube, central venous pressure catheter etc. A total number of 692 samples were administered to the microbiology department of the hospital, to be cultured on selective and then differential media. Once the bacteria were distinguished, their sensitivity for antibiotics was studied. From the total of 692 specimens, 192 pertained to patients in the intensive care unit, and 500 were obtained from patients in the general wards. Gram positive bacteria and fungi were more frequent in the ICU, whereas Gram negative bacteria were more frequently found in the general wards (p=0.001). The most common bacteria found in the ICU and general wards wereKlebsiella (22.4%) and Escherichia coli (31.6%), respectively. In the ICU, the most frequent resistance was observed against Ceftazidime (87.9%), while the lowest resistance was against Vancomycin (7.7%). In general wards, Ceftriaxone indicated the greatest resistance (78.6%), with Vancomycin having the lowest resistance observed (9%). The antibiotic resistance against most antibiotics was significantly higher in the ICU compared to general wards (p=0.01). The findings of this study indicate that many Gram positive and negative bacteria are frequently encountered in the ICU. In addition, antibiotic resistance, particularly multi-drug resistance, is frequent among microorganisms of the ICU, as well as the general wards. Key words: Intensive care unit, general ward, bacterial infection, antibiotic resistance.