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.

Acinetobacter baumannii is one of the most important nosocomial pathogen worldwide. This study aimed to investigate the virulence potential and genomic relatedness of A. baumannii strains isolated from patients hospitalized in the Military Medical Academy (MMA) by detecting OXA-type carbapenemases genes, biofilm-associated genes, and by RAPD analysis. PCR was used to detect the blaoxa genes, ISAba-1 genetic element, and biofilm-associated genes. The genomic relatedness was determined by RAPD analysis using four different primers (AP2, DAF4. M13, and DECA). blaoxa-51-like, blaoxa-23-like, blaoxa-24-like, and blaoxa-58-like were present in 100%, 34.0%, 62.4%, and 3.1% of isolates, respectively. All isolates had the ISAba1 sequence in their genome, in 35.1% of isolates it was associated with the blaoxa-51-like, and in 97.0% with the blaoxa-23-like gene. Biofilm-associated genes bap, ompA, epsA, csuA/BABCDE, and pgaABCD were detected in 93.8%, 95.8%, 88.1%, 98.4%, and 98.9% isolates, respectively. RAPD analysis showed a high degree of genome similarity and clonal dispersion of the isolates. Detection of blaoxa genes, especially biofilm-associated genes, in a high percentage of A. baumannii isolates indicated their great pathogenic potential. RAPD analysis revealed a high level of genomic similarity and clonal dispersion of the majority of isolates through MMA. Further, a continuous introduction of individual strains with different profiles contributes to the genetic diversity of A. baumannii isolates. These results can be useful for further management and tracking nosocomial outbreaks.

Background/Aim. Klebsiella (K.) pneumoniae is a frequent cause of healthcare-associated infections (HAI), particularly in intensive care units. Carbapenem-resistant strains represent a serious threat due to high mortality and limited therapeutic options. The aim of this study was to identify clinical predictors of 30-day mortality and to determine the presence of carbapenemase genes among K. pneumoniae isolates. Methods. A retrospective cohort study was conducted at the Military Medical Academy in Belgrade, Serbia. It included 121 patients with HAI caused by K. pneumoniae between January 2022 and December 2023. Clinical data were collected through active HAI surveillance. Isolation and antimicrobial susceptibility testing were per-formed according to standard microbiological procedures, and detection of carbapenemase genes was carried out using multiplex polymerase chain reaction. Survival was analyzed using the Kaplan-Meier method, and predictors of mortality were assessed using Cox regression analysis. Results. Thirty-day mortality was 59.5%. High resistance rates were observed to aminoglycosides (84.3%), fluoroquinolones (94.2%), and carbapenems (95.9%), while 67.8% of isolates were multidrug-resistant. The most common gene was blaOXA-48-like (45.5% in 2022 and 65.9% in 2023), followed by blaNDM (22.7% in 2022 and 4.5% in 2023), while blaKPC was detected only in isolates from 2023 (23.9%). The most frequently detected combination of carbapenemase genes was blaNDM + blaOXA-48-like (31.8% in 2022 and 5.7% in 2023). Detected genes had no significant effect on survival. Age ≥ 70 years, bloodstream infection, and intensive care units stay were identified as independent predictors of 30-day mortality. Conclusion. The high mortality among patients with HAI caused by carbapenem-resistant K. pneumoniae strains was primarily associated with patient characteristics and disease severity rather than the presence of specific carbapenemase genes.