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.

Background: Ventilator-associated pneumonia (VAP) is the most monitored form of respiratory tract infections (RTIs). A small number of epidemiological studies have monitored community-acquired pneumonia (CAP), non-ventilator hospital-acquired pneumonia (NV-HAP) and ventilator-associated tracheobronchitis (VAT) in intensive care units (ICUs). The objective of this study was to assess the frequency, etiology, mortality, and additional costs of RTIs. Methods: One-year prospective RTI surveillance at a 30-bed ICU. The study assessed the rates and microbiological profiles of CAP, VAP, NV-HAP, VAT, and VAP prevention factors, the impact of VAP and NV-HAP on the length of ICU stays, and the additional costs of RTI treatment and mortality. Results: Among 578 patients, RTIs were found in 30%. The CAP, NV-HAP, VAP, and VAT rates/100 admissions were 5.9, 9.0, 8.65, and 6.05, respectively. The VAP incidence density/1000 MV-days was 10.8. The most common pathogen of RTI was Acinetobacter baumannii MDR. ICU stays were extended by VAP and NV-HAP for 17.8 and 3.7 days, respectively, and these RTIs increased the cost of therapy by 13,029 and 2708 EUR per patient, respectively. The mortality rate was higher by 11.55% in patients with VAP than those without device-associated and healthcare-associated infections (p = 0.0861). Conclusions: RTIs are a serious epidemiological problem in patients who are admitted and treated in ICU, as they may affect one-third of patients. Hospital-acquired RTIs extend hospitalization time, increase the cost of treatment, and worsen outcomes.

Background: Colistin is increasingly used to treat severe infections caused by multi-drug-resistant (MDR) bacteria, particularly in critically ill patients. Its effectiveness, especially in monotherapy, remains controversial. This study aimed to evaluate the effectiveness and toxicity of colistin therapy in severe MDR infections. Methods: This retrospective study included patients treated with colistin (CMS) at the ICU. Patients’ treatments were divided into four subgroups: monotherapy vs. combination therapy, empirical vs. targeted therapy, intravenous vs. intravenous plus inhaled therapy, and standard doses with and without a loading dose. The primary outcome was clinical cure. Secondary outcomes included microbiological eradication, survival rate, and drug-related toxicity, particularly acute kidney injury (AKI). Exclusion criteria included Gram-positive infection, inhaled therapy alone, use of colistin <5 days. Results: A total of 150 patients (mean age 60 ± 18 years, APACHE II score 17 ± 10) were included. The most frequent condition was hospital-acquired pneumonia (n = 140, 93.3%). The most common pathogen was MDR Acinetobacter baumannii (n = 146, 97.3%). In most patients, colistin therapy was targeted (n = 113, 75.3%) and combined with other antibiotics (n = 124, 82.7%). Inhaled CMS was added in 47 (31.3%) patients. Mean duration of therapy was 10 ± 4 days. Clinical cure occurred in 64 (42.7%) patients, microbiological eradication in 20 (13.3%). AKI developed in 65 (53.7%) patients. Inhaled CMS improved the clinical cure rates (57.4% vs. 37.0%, p = 0.003). Conclusions: Intravenous CMS was mainly used for MDR Acinetobacter baumannii-related pneumonia. Clinical cure was observed in 42.7% of patients, but renal toxicity was high. Combining intravenous and inhaled CMS may improve outcomes.