Pathogens of ıntensive care unit-acquired ınfections and their antimicrobial resistance: a 9-yearanalysis of data from a university hospital

Abstract

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.