Pseudomonas aeruginosa device associated - healthcare associated infections and its multidrug resistance at intensive care unit of University Hospital: polish, 8.5-year, prospective, single-centre study.

Background: Pseudomonas aeruginosa has recently shown to be one of the most important strains of bacteria and alert pathogens in Europe among Intensive Care Unit patients that provide serious therapeutic problems because of its multidrug resistance.

Methods: The purpose of this microbiological study was data analysis of device associated- healthcare associated infections (DA-HAIs) in an ICU in terms of the incidents of P.aeruginosa strain infections and its susceptibility within an 8.5-year observation.

Results: Among 919 isolated strains responsible for 799 DA-HAIs (17,62 ± 1,98/1000 patient-days) in 4010 ICU patients P.aeruginosa was the pathogen in 108/799 (13.52%) cases. Incidence rate (density) of: VAP/1000 MV- days, UTI /1000 UC- days and CLA-BSI/1000 CL- days were 11,15 ± 2.5, 6.82 ± 0.81, 2.35 ± 1.54.respectivelly. P.aeruginosa was the pathogen most frequently responsible for VAP 69/108 (63.88%). Mean frequency of VAP, UTI and CLA-BSI with P.aeruginosa etiology was 69/493 (14.28%), 32/299 (11.1%) and 7/127 (5.77%) respectively. The mean density of P.aeruginosa infection amounted to 2.43/1000 patient-days. The decrease was observed in the total number of DA-HAIs caused by the P.aeruginosa from 15.75% and 3.23/1000 patient-days in 2011 to 5.0% and 1.17/1000 in 2016 (p = 0.0104, p = 0.0348). Starting from 2016 to 2019 incidence and density of P.aeruginosa DA-HAIs increased to 12.33% and 2.63/1000 (p = 0.1388, p = 0.0818). P.aeruginosa was susceptible to ceftazidime, cefepime, amikacin, meropenem, ciprofloxacin, colistin, in 55.55, 58.33, 70.37, 53.73, 50, and 100% respectively. MDR characterised it in 40% in 2011 and 66.7% in 2019, (p = 0.177).

Conclusions: The study revealed a changeable prevalence of P. aeruginosa strain infections; however their frequency was never highest in our ICU patients as it presented in the last years in Europe. The study showed a significant decrease in 2016 and increase in 2019, a nearly 3-fold increase of P.aeruginosa infections among Gram-negative strain infections, and a 2-fold increase of the P.aeruginosa DA-HAIs frequency between 2016 and 2019 as well as an increased resistance. Microbiological analysis of DA-HAIs in each hospital should be a standard method used in hospital infection control and antibiotic policy. In the case of P.aeruginosa, in order to minimize transmission, preventive infection methods should be assessed mainly in case of VAP.