pathogens of intensive care unit-acquired infections and their antimicrobial resistance: a 9-year analysis of data from a university hospital

Background: pathogens surveillance and antimicrobial resistance are essential for the prompt organization of therapeutic and preventive actions in healthcare settings. objectives:we investigated the causative agents of intensive care unit (icu)-acquired infections and their antimicrobial resistance in a university hospital over a nine-year period. methods: an active, prospective surveillance was conducted in the icus of a tertiary care hospital between 2007 and 2015. the changing patterns in the frequency of pathogens and their antimicrobial resistance by the time were statistically evaluated with mann-whitney u test. results: a total of 3044 pathogens were isolated from 4272 healthcare-associated infections attacks in 3437 patients. the most frequently detected organisms were acinetobacter spp. (n = 1060, 34.8%), pseudomonas aeruginosa (n = 622, 20.4%), escherichia coli (n = 340, 11.1%), klebsiella pneumoniae (n = 331, 10.8%), and candida spp. (n = 285, 9.3%). carbapenem resistance among acinetobacter spp., p. aeruginosa, e. coli, and k. pneumoniae was found as 82%, 30.7%, 2%, and 9.3%, respectively. the prevalence of extended-spectrum betalactamase (esbl) among e. coli and k. pneumoniae was 49.7% and 41.3%, orderly, and methicillin resistance in staphylococcus aureus was 81.8%. substantial reductions occurred in the rates of e. coli (16.8% to 8.9%), s. aureus (11% to 3.2%), coagulase-negative staphylococci (7.9% to 0), and stenotrophomonas maltophilia (4.2% to 0.3%) during the study period by the applied infection control measures while the rate of acinetobacter spp. (9.7% to 51%) significantly increased. furthermore, the increases in the carbapenem resistance among acinetobacter spp. (52.5% to 91.4%), pseudomonas spp. (25.7% to 51.6%), e. coli (0 to 12.7%), and k. pneumoniae (2.6% to 9%) and the decrease in the prevalence of esbl-producing e. coli (57% to 27.2%) were statistically significant. conclusions: despite the decreases in the frequencies of staphylococci and some gram-negative bacteria, the current infection control measures have been unable to limit the spread of carbapenem-resistant gram-negative bacteria in our facility. additional precautions are required to control such pathogens in the intensive care units.