# Metagenomic Analysis of Bacterial Diversity on Reusable Tourniquets in Hospital Environments
## 4 Discussion  
### Key Findings and Departmental Variability  
Studies have demonstrated the presence of microorganisms on hospital tourniquets that are among the most common causative agents of healthcare-associated infections (HAIs), including _K. pneumoniae_, _K. aerogenes_, _E. faecalis_, _A. baumannii_, _A. lwoffii_, _S. aureus_, and _P. aeruginosa_. According to the European Centre for Disease Prevention and Control (ECDC) reports from 2022 and 2023, in Poland, _Klebsiella_ species are responsible for approximately 16% of all reported HAIs, making them the leading cause of hospital-acquired infections nationwide. _Enterococcus_ spp. accounts for 11.6% of cases, _S. aureus_ for 8.8%, _P. aeruginosa_ for 7%, and _Acinetobacter_ spp. for 5.7%. _Klebsiella_ spp. are most associated with urinary tract infections. _Enterococcus_ spp. is frequently linked to surgical site infections, while _S. aureus_ is predominantly involved in bloodstream infections and surgical site infections. _P. aeruginosa_ and _Acinetobacter_ spp. are primarily associated with pneumonia and lower respiratory tract infections [10]. The clinical significance of _Klebsiella pneumoniae_ is further underscored by the increasing prevalence of carbapenem-resistant strains (CRKP), which are associated with severe outcomes, limited treatment options, and high mortality rates, particularly among ICU patients [11]. Figure 3: Heatmap presenting relative abundance of the pathogenic bacterial species identified on tourniquets. In the presented study, most tourniquets were contaminated by pathogens of the genus _Acinetobacter_ (including _Acinetobacter baumannii_ and _Acinetobacter lwoffii_), which were detected in 10 out of 12 samples. Although _Acinetobacter_ is not the leading cause of hospital-acquired infections, data from the ECDC report raise concern, indicating that 82.9% of _Acinetobacter_ strains isolated from healthcare-associated infections exhibit resistance to carbapenems (CAR-R) [10]. A study made by [PERSON] and [PERSON] in the intensive care unit (Wroclaw, Poland) revealed that 32% of healthcare-associated infections were caused by _A. baumannii_. During the study period, a statistically significant increase in infections caused by this bacterium was observed, from 16.5% of HAIs in 2011 to 41% in 2016. Notably, 73.8% of these cases were associated with ventilator-associated pneumonia. The study also found that 98.36% of the isolates were multidrug-resistant (MDR), highlighting the serious clinical challenge posed by this species, particularly in units treating immunocompromised patients [12]. A study conducted in southern Poland between 2016 and 2019 in an intensive care unit involving 3028 patients revealed that the two main causative agents of infections were _K. pneumoniae_ (16.3%) and _A. baumannii_ (14.4%). _A. baumannii_ was primarily responsible for pneumonia and lower respiratory tract infections (34.9%), while _K. pneumoniae_ was most commonly associated with urinary tract infections (20.2%--the second most frequent cause after _Escherichia coli_) as well as bloodstream infections (16.7%) [13]. In a study conducted in Poland between 2014 and 2019 by [PERSON] and [PERSON] in neurosurgery departments of two hospitals, _A. baumannii_ was responsible for 8.8% of all healthcare-associated infections, with pneumonia being the predominant type, accounting for 21.7% of cases in Hospital A [14]. In a study by [PERSON] and [PERSON], conducted between 2014 and 2018 on orthopedic patients (6261 patients, 111 cases of healthcare-associated infections), _Acinetobacter baumanni_ was identified as the causative agent in 4.5% of the infections [15]. The next most frequently identified pathogens on the examined tourniquets were _E. faecalis_ and _P. aeruginosa_, both detected on 9 out of 12 samples. In studies conducted by [PERSON] and [PERSON] (2021) [13], _E. faecalis_ was responsible for 7.1% of HAIs, mostly urinary tract infections (14.5%), and bloodstream infections (8.3%). _P.