Bacterial species: etiologic agents of nosocomial infections

Objective: evaluation of different bacterial species involved in etiology of nosocomial infections and joint analysis of nosocomial infections with multiple etiologies. Material and Methods: during January-July 2010 in the SPCIN (Prevention and Control of Nosocomial Infections Department) of Emergency Clinical Hospital "Prof. Dr. O. Fodor" Cluj-Napoca, we have investigated a number of 201 nosocomial infections. The blood cultures have been processed using the Bactec system, the rest of samples have been processed through conventional methods. The strains have been identified through classical biochemical methods and through Vitek 2 Compact (BioMerieux) system. Results: nosocomial infections were analyzed by infection site and pathogen distribution. Most frequent types were bronchopneumonia (30%), postoperative wound infections (24%), followed by urinary tract infections (17%) and septicemia (17%). Approximately 36.5% of bloodstream infections were associated with central lines, 82.4% of nosocomial pneumonia were associated with mechanical ventilation and 54.4% of urinary tract infections were associated with urinary catheters. Coagulase-negative staphylococci (18%) and Acinetobacter baumannii (18%) were the most common bloodstream infections isolates. The most frequent isolates from urinary tract infections were Enterococcus spp. (20%) and Candida tropicalis (20%).The most frequent isolates from postoperative wound infections were A. baumannii (20%) and Klebsiella pneumoniae (14%). From pneumonia isolates, the most frequent were Gram-negative organisms (72%). A. baumannii (40%) was the most frequently isolated of these, followed by K. pneumoniae (12%), Staphylococcus aureus (12%) and Pseudomonas aeruginosa (8%). Conclusion: the most frequent types of nosocomial infections were bronchopneumonia (30%), especially in intensive care units (45%), followed by septicemia (23%). Regarding the isolated microorganisms, it is noted an increased frequency or Gram-negative organisms (60%), both enterobacteria (30%) and nonfermenter species (30%). The most frequently isolated was A. baumannii, alone or in bacterial association. Approximately 8% of isolates were fungi. Certain pathogens were associated with device use: coagulase-negative staphylococci with central lines, fungal infections with urinary catheters, A. baumannii and P. aeruginosa with ventilators.