Purpose: Amongst all etiologic hospital-acquired infection factors, K. pneumoniae strains producing New Delhi metallo-β-lactamase (KP-NDM) belong to pathogens with the most effective antibiotic resistance mechanisms. Clinical guidelines recommend using ceftazidime/avibactam with aztreonam (CZA + AT) as the preferred option for NDM-producing Enterobacterales. However, the number of observations on such treatment regimen is limited. This retrospective study reports the clinical and microbiological outcomes of 23 patients with KP-NDM hospital-acquired infection treated with CZA + AT at a single center in Poland. Methods: The isolates were derived from the urine, lungs, blood, peritoneal cavity, wounds, and peritonsillar abscess. In microbiological analysis, mass spectrometry for pathogen identification, polymerase chain reaction, or an immunochromatographic assay for detection of carbapenemase, as well as VITEK-2 system, broth microdilution, and microdilution in agar method for antimicrobial susceptibility tests were used, depending of the pathogens’ nature. CZA was administered intravenously (IV) at 2.5 g every eight hours in patients with normal kidney function, and aztreonam was administered at 2 g every eight hours IV. Such dosage was modified when renal function was reduced. Results: KP-NDM was eradicated in all cases. Four patients (17.4%) died: three of them had a neoplastic disease, and one - a COVID-19 infection. Conclusion: The combination of CZA + AT is a safe and effective therapy for infections caused by KP-NDM, both at the clinical and microbiological levels. The synergistic action of all compounds resulted in a good agreement between the clinical efficacy of CZA + AT and the results of in vitro susceptibility testing.

Background/Objectives: Modern healthcare faces a growing burden of antimicrobial resistance, prominently driven by ESKAPE pathogens. These organisms—Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.—are the leading causes of healthcare-associated infections, associated with limited therapeutic options and increased morbidity. Continuous surveillance is crucial for informing empirical therapy and guiding stewardship. Methods: We perform a single-center, seven-year retrospective study (2018–2024) at a 1000-bed tertiary hospital in Warsaw, Poland. Bloodstream isolates of ESKAPE pathogens were identified according to the EUCAST guidelines. Data were analyzed by pathogen, ward, and year of isolation. Results: From 2483 positive blood cultures, 3724 ESKAPE pathogens were recovered. S. aureus and K. pneumoniae predominated, particularly in the Intensive Care Unit and Hematology ward. Resistance analysis revealed persistently high vancomycin resistance in E. faecium, variable but notable methicillin resistance in S. aureus, and frequent ESBL production in K. pneumoniae with an alarming rise in carbapenemase-producing strains, including dual NDM + OXA-48 co-producers. A. baumannii exhibited near-universal multidrug resistance. P. aeruginosa demonstrated lower resistance rates with preserved colistin susceptibility, while Enterobacter spp. remained fully carbapenem-susceptible. Linezolid retained activity against E. faecium, while colistin remained effective against A. baumannii and P. aeruginosa. Modern β-lactam/β-lactamase inhibitor combinations were active against K. pneumoniae. Conclusions: Our findings underscore the critical role of ESKAPE pathogens in bloodstream infections and highlight divergent resistance patterns across species. The emergence of carbapenemase-producing K. pneumoniae and the persistence of multidrug-resistant A. baumannii are of particular concern. Sustained surveillance, robust antimicrobial stewardship, and tailored infection control strategies remained essential to curb the evolving resistance threat in tertiary care settings.

Background/Objectives: Stenotrophomonas maltophilia is a critical opportunistic pathogen, yet its long-term epidemiology remains underrepresented in global surveillance frameworks like WHO GLASS. We aimed to analyze its six-year epidemiological trend in a large Polish tertiary hospital. Methods: A retrospective study (2020–2025) of 399 non-duplicate isolates was conducted. Identification was performed using MALDI-TOF MS, and susceptibility was analyzed according to EUCAST breakpoints. Antibiotic consumption (DDD/100 patient-days) was correlated with isolation trends. Results: Wound/skin (36.8%) and lower respiratory tract (35.8%) samples predominated. A significant rise in respiratory isolates was observed post-2020, coinciding with peak carbapenem consumption in ICU and surgical wards. Ward-level analysis demonstrated that intensive care unit status (β = 68.9, 95% CI 46.1–91.8, p < 0.001) and carbapenem consumption (β = 0.080, 95% CI 0.004–0.156, p = 0.041) were independently associated with S. maltophilia isolation burden after adjustment for ward type (adjusted R² = 0.80). While trimethoprim–sulfamethoxazole remained highly active, levofloxacin susceptibility showed high interannual variability. Conclusions: S. maltophilia is a stable and clinically significant threat in high-intensity hospital environments. Our findings support the inclusion of this pathogen in international AMR monitoring (GLASS) and emphasize strict carbapenem stewardship to curb its emergence.

Introduction and objective: Acute gastroenteritis, a common childhood illness worldwide, manifests with symptoms including fever, abdominal pain, vomiting, and diarrhoea. It is highly contagious, with transmission occurring through contaminated water, food, or poor hygiene. Globally, 1.7 billion cases of diarrhoeal diseases are diagnosed annually, causing approximately 525,000 deaths among children under the age of five. Dehydration caused by diarrhoea is a primary cause of hospitalisation, particularly in developing countries. Aim: Analysis of the aetiology, frequency, and seasonal distribution of viral pathogens responsible for acute gastroenteritis in children hospitalised between 2019 and 2022 at the Military Institute of Medicine – National Research Institute in Warsaw, Poland. Materials and methods: Medical records of patients aged 0 to 18 diagnosed with rotavirus, norovirus, and adenovirus-induced acute gastroenteritis were analysed. The pathogens had been identified with reliable immunochromatographic tests. Exclusion criteria encompassed bacterial infections, dietary errors, and inflammatory conditions. Data examined included age, gender, aetiology of gastroenteritis, seasonality, duration of hospitalisation, and clinical symptoms (diarrhoea, vomiting, fever, abdominal pain, and dehydration). Laboratory results such as white blood cell count, C-reactive protein, electrolyte levels, and organ function markers were also evaluated. Results: Data from 350 children hospitalised between 2019 and 2022 were analysed. The highest number of hospitalisations occurred in 2019 and 2022, with fewer cases in 2020–2021, likely reflecting the impact of the COVID-19 pandemic. Most patients were between 6 and 12 months old. Rotavirus infection commonly presented with fever, vomiting, diarrhoea, and dehydration. Adenovirus and mixed infections were associated with slightly higher C-reactive protein levels, while rotavirus infections showed mildly elevated aspartate aminotransferase levels. Haematocrit, blood urea nitrogen, creatinine, and electrolyte levels were similar across all cases. Conclusions: Our analysis showed that rotavirus was the most frequent cause of acute viral diarrhoea in children, followed by norovirus and adenovirus, with mixed infections being the least common. The peak incidence occurred in autumn and winter, except in 2021, reflecting changes in the dynamics of infections related to the coronavirus pandemic. Biochemical findings were not sufficiently characteristic to infer the aetiology of the disease.