Background: Carbapenem-resistant Klebsiella pneumoniae (CRKp) is a critical global health threat due to its multidrug resistance, primarily driven by carbapenemase production. Rapid and accurate detection of carbapenemases is essential for effective treatment and infection control. This study evaluates the validity of the NG-Test CARBA 5, a rapid immunochromatographic assay, for detecting five major carbapenemases (KPC, NDM, VIM, IMP, OXA-48-like) in clinical CRKp isolates. Methods: Clinical isolates of CRKp were collected from various clinical specimens at the Military Medical Academy in Belgrade, Serbia, between January 2023 and October 2024. Detection of carbapenemases was performed using NG-Test CARBA 5, while PCR served as the reference method. Diagnostic performance was assessed by calculating sensitivity, specificity, and Cohen’s kappa coefficient. Results: Among 312 isolates, OXA-48-like was the most prevalent carbapenemase. NG-Test CARBA 5 showed high sensitivity (98.7%) and specificity (100%) overall, with excellent agreement for NDM (κ = 0.947), OXA-48-like (κ = 0.957), and KPC (κ = 0.978). However, it failed to detect VIM in five PCR-positive isolates, suggesting potential limitations. Conclusions: NG-Test CARBA 5 is a rapid and reliable tool for detecting major carbapenemases in CRKp, though its performance for VIM detection requires further investigation. This assay has the potential to improve clinical diagnostics and strengthen infection control in settings with high antimicrobial resistance.

Background: Carbapenem-resistant Klebsiella pneumoniae (CRKp) is a critical global health threat due to its multidrug resistance, primarily driven by carbapenemase production. Rapid and accurate detection of carbapenemases is essential for effective treatment and infection control. This study evaluates the validity of the NG-Test Carba 5, a rapid immunochromatographic assay, for detecting five major carbapenemases (KPC, NDM, VIM, IMP, OXA-48-like) in clinical CRKp isolates. Methods: Clinical isolates of CRKp were collected from various clinical specimens at the Military Medical Academy in Belgrade, Serbia, between January 2023 and October 2024. Detection of carbapenemases was performed using NG-Test Carba 5, while PCR served as the reference method. Diagnostic performance was assessed by calculating sensitivity, specificity, and Cohen’s kappa coefficient. Results: Among 312 isolates, OXA-48-like was the most prevalent carbapenemase. NG-Test Carba 5 showed high sensitivity (98.7%) and specificity (100%) overall, with excellent agreement for NDM (κ = 0.947), OXA-48-like (κ = 0.957), and KPC (κ = 0.978). However, it failed to detect VIM in five PCR-positive isolates, suggesting potential limitations. Conclusion: NG-Test Carba 5 is a rapid and reliable tool for detecting major carbapenemases in CRKp, though its performance for VIM detection requires further investigation. This assay has the potential to improve clinical diagnostics and strengthen infection control in settings with high antimicrobial resistance.

Background: Healthcare-associated infections (HAIs), antimicrobial resistance (AMR), and antibiotic use (AU) remain critical challenges in intensive care units (ICUs). Reliable long-term surveillance is essential to inform stewardship programs and infection prevention. Methods: We conducted a seven-year ecological study (2018–2024) of adult patients admitted to the surgical ICU of a Serbian tertiary university hospital. Patients with ICU stays >48 h were included. Data on demographics, HAIs, AU expressed as ‘days of therapy’ (DOT) per 100 patient-days, and resistance profiles of key pathogens were collected. AU was classified by WHO Access, Watch and Reserve categories. Trends were analyzed, and correlations between AU and healthcare-associated Clostridioides difficile infection (HA-CDI) incidence density as well as changes in AMR rates were assessed. Direct expenditures for antibiotic therapy were also calculated. Results: Among 2055 patients, 511 (24.9%) developed at least one HAI. HA-CDI showed a marked upward trend. Overall, AU was stable, but Reserve antibiotics increased significantly (R² = 0.456), particularly linezolid, colistin, and ceftazidime–avibactam. Resistance to carbapenems and colistin in Klebsiella pneumoniae (K. pneumonia) demonstrated alarming trends. A strong correlation was observed between colistin use and colistin resistance in K. pneumoniae. Antibiotic expenditures peaked in 2023 at more than double pre-COVID levels, mainly driven by Reserve agents. Conclusions: This study reveals a concerning rise in multidrug-resistant pathogens, escalating Reserve antibiotic use, and substantial financial burden. Strengthened antimicrobial stewardship, optimization of Access, restriction of Reserve agents, and investment in infection prevention and surveillance are urgently needed.

(1) Background: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its resulting coronavirus disease 2019 (COVID-19) has caused a fast-moving pandemic. Diagnostic testing, aimed to identify patients infected with SARS-CoV-2, plays a key role in controlling the COVID-19 pandemic in different populations. (2) Methods: This retrospective cohort study aimed to investigate predictors associated with positive polymerase chain reaction (PCR) SARS-CoV-2 test results in hospitalized patients, healthcare workers (HCWs), and military personnel (MP) during 2020, before the widespread availability of COVID-19 vaccines. Persons with a positive test result were compared with persons with a negative test result in three cohorts during the study period. (3) Results: A total of 6912 respondents were tested, and 1334 (19.3%) of them had positive PCR SARS-CoV-2 test results. Contact with a known COVID-19 case within 14 days (p < 0.001; OR: 1.48; 95% CI: 1.25–1.76), fever (p < 0.001; OR: 3.66; 95% CI: 3.04–4.41), cough (p < 0.001; OR: 1.91; 95% CI: 1.59–2.30), headache (p = 0.028; OR: 1.24; 95% CI: 1.02–1.50), and myalgia/arthralgia (p < 0.001; OR: 1.99; 95% CI: 1.65–2.42) were independently associated with positive PCR SARS-CoV-2 test results in the cohort of MP. Furthermore, fever (p < 0.001; OR: 2.75; 95% CI: 1.83–4.13), cough (p < 0.001; OR: 2.04; 95% CI: 1.32–3.13), headache (p = 0.008; OR: 1.76; 95% CI: 1.15–2.68), and myalgia/arthralgia (p = 0.039; OR: 1.58; 95% CI: 1.02–2.45) were independently associated with positive PCR SARS-CoV-2 test results in the cohort of HCWs. Moreover, independent predictors of positive PCR SARS-CoV-2 test results in hospitalized patients were contact with a known COVID-19 case within 14 days (p < 0.001; OR: 2.56; 95% CI: 1.71–3.83), fever (p < 0.001; OR: 1.89; 95% CI: 1.38–2.59), pneumonia (p = 0.041; OR: 1.45; 95% CI: 1.01–2.09), and neurological diseases (p = 0.009; OR: 0.375; 95% CI: 0.18–0.78). (4) Conclusions: According to data gathered from cohorts of hospitalized patients, HCWs, and MP, before the widespread availability of COVID-19 vaccines in Serbia, we can conclude that predictors of positive PCR SARS-CoV-2 test results in MP and HCWs were similar. Accurate estimates of COVID-19 in different population groups are important for health authorities.

The COVID-19 pandemic prompted rapid vaccine development and deployment worldwide. Despite widespread vaccination efforts, understanding the effectiveness of vaccines in hospitalized patients remains a critical concern. This retrospective cohort study, conducted at a tertiary healthcare centre in Serbia, tracked patients hospitalized during different waves of COVID-19 variants—Alpha, Delta, and Omicron. Data collection included demographics, comorbidities, symptoms, and vaccination status. Among 3593 patients, those with prior exposure to COVID-19 cases or hospital treatment showed higher positivity rates. Symptom prevalence varied across waves, with coughs persisting. Patients without chronic diseases were more frequent among those testing negative. Vaccine effectiveness varied, with Sinopharm demonstrating a 45.6% effectiveness initially and Pfizer-BioNTech showing an effectiveness of up to 74.8% within 0–84 days after the second dose. Mixed-dose strategies, notably Sinopharm as a primary dose followed by a Pfizer-BioNTech booster, suggested increased protection. Despite substantial vaccination availability, a significant portion of hospitalized patients remained unvaccinated. This study underscores the dynamic nature of vaccine effectiveness and advocates for booster strategies to address evolving challenges in combating COVID-19, particularly in hospitalized patients.

Oral squamous cell carcinoma (OSCC), a malignancy with high recurrence rate and poor survival, may be influenced by immune-related genetic variations and oncogenic viruses. Objective This study evaluated the clinical relevance of EBI3 polymorphisms, along with tumor Epstein–Barr virus (EBV) and Human Cytomegalovirus (HCMV) status, in prognostically adverse HPV-negative OSCCs. Methodology EBI3 (rs4740, rs4905, rs428253) genotyping was performed by qPCR in 95 HPV-negative OSCC patients and 108 age- and sex-matched controls. Tumor HPV, EBV, and HCMV status were assessed by qPCR. EBV viral load was calculated by exponential approach and a relative estimate of EBV copies per 105 cells. Associations with overall survival (OS) and recurrence-free survival (RFS) were evaluated by Kaplan-Meier and Cox regression analyses. Results EBV-positive tumors showed a significant association with increasing nodal stage (P=0.020). EBV viral load stratification (negative, low, high) presented a non-significant trend toward association with advanced tumor stage (P=0.060). Notably, EBI3 rs428253 predicted worse OS in EBV-positive patients, whereas rs4740 and rs4905 variants were associated with advanced tumor stage (P=0.024 and P=0.018). rs4740 and rs4905 variants were inversely associated with OSCC risk in dominant and overdominant models. Analysis detected HCMV in 7.4% of tumors but was not clinically relevant. Conclusions EBI3 genetic variants and EBV status may have prognostic relevance in HPV-negative OSCC. EBV may interact with the host genetics to influence nodal metastases and outcomes, suggesting a potential EBV-EBI3 axis, which warrants further investigation. Future precision oncology approaches may incorporate host and viral genetic markers to identify and stratify high-risk HPV-negative OSCC patients.