Сезонски варијации на ендемска еко-флора во хируршка интензивна единица и нивна генотипска конфирмација

Abstract

Introduction: Nosocomial infections are the most common in intensive care units and have the most severe course and outcome compared to all other infections. At least half of all intrahospital infections in intensive care units are related with the use of medical devices. Their colonization with microorganisms is a precondition for nosocomial infection. Gram-negative bacteria: Acinetobacter spp., Pseudomonas aeruginosa, bacteria of the Enterobacteriaceae family and Gram-positive MRSA strains are the most common colonizers. The incidence of Acinetobacter spp., isolated from intubated surgical patients from the Clinic of Anesthesiology, Resuscitation and Intensive Care (CARIC) has been 29-40% in the last two decades, with a tendency to increase its prevalence, highlighting this microorganism as the most important intrahospital pathogen. Objectives: The aim of the study was to specify bacterial colonization of endotracheal tubes and nasal cannulas in CARIC patients, to detect the most common intrahospital microorganisms and to indicate their seasonal specificity and necessary prevention. Material and methods: This research was a retrospective, analytical cross-sectional study, for a period of eight years (2010 - 2017). The study processed routinely obtained materials from endotracheal tubes and nasal cannulas of CARIC patients sent for microbiological analysis to the Institute of Microbiology and Parasitology at the Medical Faculty, ―Ss. Cyril and Methodius‖ University in Skopje. The laboratory data were obtained by a computer search method through the laboratory software for daily routine work (LabIS-Codex) at the Institute of Microbiology and Parasitology. The isolation rate was compared with two climatic parameters: average humidity and average air temperature. The official data on climate parameters were obtained from the Hydrometeorological Service. The presence of a certain genotype of Acinetobacter spp. was determined by a molecular method of genotyping with rep-PCR (repetitive polymerase chain reaction), performed with the DiversiLab system. Results: The most common bacteria from the micro flora of the inanimate environment in CARIC were: Acinetobacter spp., Pseudomonas aeruginosa, Klebsiella spp. and MRSA. As expected, most commonly isolated were the Acinetobacter spp. strains (36,96%), with endemic presence of two genotypes. Acinetobacter spp. was significantly more present in the tubes than in the cannulas (p=0,0001). Pseudomonas aeruginosa (p=0,0001) and Klebsiella spp. (p=0,0091) are more significantly represented in the cannula than in the tube. While the developing tendency of presence of Acinetobacter spp. grows, the trends of Pseudomonas aeruginosa and Klebsiella spp. in the whole sample - decrease. The seasonal index of Acinetobacter spp. and Pseudomonas aeruginosa, state values above 100% (above the monthly average) were highest in November, December and February for both bacteria (months with the highest humidity). As the humidity increases, so does the presence of Klebsiella spp. (p=0,0281) and MRSA strains (p=0,0767) throughout the sample. The isolation of Enterobacter spp., Enterococcus spp. and Escherichia coli also increases with the increased humidity in tubes and cannulas isolates, and according to seasonal variations, March is the most critical for the development of these three bacteria. Conclusions: The detection of Acinetobacter spp. and the other most common inanimate micro flora in CARIC can be used to prevent, diagnose, predict empirical therapy and reduce intrahospital infections caused by most commonly detected bacteria. Determining the seasonal variation of the most common bacteria in the hospital environment contributes for a stronger global and seasonally specific preventive measures in hospitals in the critical seasons.