Dorota Pastuszak-Lewandoska

Background: Non-small cell lung cancer (NSCLC) remains the leading cause of cancer-related mortality worldwide despite advances in diagnosis and treatment. Increasing evidence suggests that alterations in the lung microbiome may contribute to NSCLC development and progression; however, findings remain inconsistent due to heterogeneous biological materials and methodological differences among studies. Therefore, this study aimed to characterize the lung tissue microbiome in NSCLC using a paired tissue-based approach. Methods: Thirty-two patients with NSCLC were enrolled. For each patient, two samples were collected: primary tumor tissue and matched macroscopically unchanged adjacent lung tissue. The V3-V4 region of the 16S rRNA gene was amplified and sequenced, followed by bioinformatic analysis using the QIIME2 pipeline. Results: Tumor tissues demonstrated lower alpha (Shannon H = 9.60, q = 0.001) and beta (Jaccard pseudo-F = 1.26, q = 0.015) diversity compared with adjacent controls, indicating reduced microbial complexity within the tumor microenvironment. Escherichia-Shigella was the most abundant detected genus (~12%) in both groups, although without a statistically significant difference. Analysis of microbiome variation in relation to spatial distance between sampled tissues revealed a strong trend toward significance (p = 0.07) with a substantial effect size (R² = 0.207). Conclusions: The observed microbiome alterations in NSCLC were more evident at the ecological level than in overall taxonomic composition, supporting a model of microbial community simplification rather than complete compositional replacement. Our findings also suggest that tumor-adjacent lung tissue may not represent a fully neutral control due to the local field effect. The relatively high abundance of Escherichia-Shigella indicates that this taxon may warrant further investigation in NSCLC microbiome studies.

Background: Acinetobacter baumannii is a non-fermenting Gram-negative bacillus responsible for severe nosocomial infections, particularly in intensive care units (ICUs). The increasing prevalence of multidrug-resistant (MDR) and carbapenem-resistant A. baumannii (CRAB) strains has become a significant challenge for infection control and antimicrobial therapy worldwide. Objectives: This study aimed to analyze the antimicrobial susceptibility patterns of clinical A. baumannii isolates recovered from a multi-profile hospital in years 2020–2024 in Lodz, Poland. Methods: Clinical isolates from various specimen types (blood, urine, wound swabs, biopsies, sputum, and bronchoalveolar lavage fluid) were obtained during routine microbiological diagnostics. Identification was performed using MALDI-TOF MS. Antimicrobial susceptibility testing (AST) was conducted using the automated VITEK^®2 system with EUCAST/CLSI interpretive criteria. Minimum inhibitory concentrations (MICs) for colistin were determined by broth microdilution. Carbapenemase production was assessed using the Carbapenem Inactivation Method (CIM) and immunochromatographic assays for OXA-23, OXA-40/58, and NDM detection. Results: A total of 244 A. baumannii isolates were recovered over the study period. Susceptibility to carbapenems (meropenem, imipenem) declined markedly, with resistance exceeding 90% by 2023–2024. Aminoglycosides exhibited variable activity, with gentamicin demonstrating the highest susceptibility rates (up to 88% in 2022). Resistance to ceftazidime and cefepime remained consistently high (>90% in 2023–2024). No fully susceptible isolates were identified for ciprofloxacin. Conclusions: The high prevalence of CRAB strains highlights the urgent need for effective infection control measures, optimized antimicrobial stewardship, and consideration of novel treatment options in the clinical setting.

The urinary tract microbiota (urobiota) in healthy individuals remains understudied, particularly in men. Methods: Expanded quantitative urine cultures were performed on 40 asymptomatic, presumably healthy males (18–40 years). Results: 88% of samples showed bacterial growth, predominated by Firmicutes ( Streptococcus , Staphylococcus , Corynebacterium ). Sexual behavior influenced diversity. Conclusions: The male urinary tract harbors a complex microbiota, challenging the “sterile urine” paradigm.

The emergence of multidrug-resistant uropathogens requires the development of novel therapeutic strategies. This pilot study assessed the in vitro synergy between nitrofurantoin and aminoglycosides (amikacin, gentamicin, and tobramycin) against three major uropathogens: Escherichia coli, Klebsiella pneumoniae, and Enterococcus faecalis. Ninety clinical isolates were tested using the disk diffusion and double-disk synergy methods. Statistical analysis included Kruskal–Wallis and Mann–Whitney U tests, as well as logistic regression models to assess associations between inhibition zone diameters and synergy occurrence. While synergy was observed in all bacterial species, it was neither universally present nor species-specific. Significant associations were identified between nitrofurantoin inhibition zone size and synergy with amikacin and tobramycin in E. coli, and with amikacin in K. pneumoniae. In E. faecalis, synergy was more likely with larger aminoglycoside inhibition zones, particularly tobramycin. These findings underscore the potential of nitrofurantoin–aminoglycoside combinations in treatment of multidrug-resistant urinary tract infections, while emphasizing the need for further studies incorporating quantitative synergy assays and clinical validation.

Accurate antimicrobial susceptibility testing (AST) of cefiderocol remains a diagnostic challenge, especially in infections caused by metallo-β-lactamase (MBL)-producing Klebsiella pneumoniae. While disk diffusion offers a cost-effective alternative to broth microdilution, it is highly sensitive to factors such as media composition and the presence of atypical colony morphology. The objective of this study was to evaluate how different agar media and interpretations of isolated colonies affect the performance and reliability of cefiderocol AST by disk diffusion. A total of 50 clinical K. pneumoniae MBL isolates were tested using disk diffusion on Columbia with blood, MacConkey, and chromogenic agars from three manufacturers. Inhibition zones were compared with MICs from broth microdilution. Statistical analyses included paired t-tests and Spearman correlation to assess media effects and zone morphology impact. Variability in inhibition zone diameters was observed between media, notably with chromogenic agar. The most consistent results were obtained using Graso Biotech and Thermo Fisher Columbia with blood agar. Isolated colonies were observed in over half the samples and, depending on how they were interpreted, led to major changes in classification accuracy. Up to 64% of results fell into the EUCAST area of technical uncertainty (ATU), and categorical agreement varied across media and interpretive criteria. Disk diffusion for cefiderocol may be used in resource-limited settings but only if rigorously standardized using validated media, consistent zone reading, and ATU-aware interpretive strategies. In borderline cases or when morphological anomalies are present, broth microdilution should be considered the sole reliable method. Clinical microbiologists are advised to exercise caution with ambiguous results and seek expert or confirmatory testing when needed.

Psychrobacter sanguinis is an emerging opportunistic pathogen predominantly isolated from cold environments that is increasingly recognized for its clinical relevance. This case report documents a rare instance of P. sanguinis bacteremia in a 69-year-old homeless patient presenting with thigh phlegmon. The patient was admitted with elevated inflammatory markers and treated empirically with antibiotics. Blood cultures identified P. phenylpyruvicus , later confirmed as P. sanguinis via 16S rRNA sequencing. Despite initial antibiotic therapy, the patient’s condition necessitated surgical intervention for phlegmon drainage. The antibiotic regimen was adjusted based on susceptibility profiles, leading to gradual clinical improvement. This case underscores the significance of accurate microbial identification in managing infections caused by less common pathogens. The severity of infection was doubtlessly influenced by the patient’s homeless status and associated risk factors, such as poor hygiene and potential environmental exposure. This report highlights the clinical implications of P. sanguinis and the importance of considering environmental pathogens in atypical presentations of bacteremia.

Background/Objectives: Clostridioides difficile infection (CDI) represents a significant public health challenge globally, driven by its increasing prevalence, hypervirulent strains like ribotype 027 (RT027), and growing antibiotic resistance. This study aimed to evaluate the prevalence of RT027 and analyze molecular markers of vancomycin and metronidazole resistance in stool samples from CDI patients hospitalized in Poland between 2017 and 2019. Methods: A total of 200 stool samples from confirmed CDI cases were analyzed for the presence of RT027, vanA (vancomycin resistance), and nim (metronidazole resistance) genes. DNA was extracted, and a polymerase chain reaction (PCR) was conducted using specific primers. Statistical associations between RT027 and resistance genes were evaluated using chi-square tests and logistic regression. Results: RT027 was detected in 14% of samples. The vanA gene, indicative of vancomycin resistance, was found in 52.5% of samples, while the nim gene, associated with metronidazole resistance, was present in 1.5% of cases. Co-occurrence of RT027 with vanA was not statistically significant. The study revealed no significant association between RT027 and vanA. Also, no significant association was observed between RT027 and nim due to the latter’s low prevalence. Conclusions: This study highlights a concerning prevalence of vanA among CDI cases, indicating widespread vancomycin resistance and challenging current treatment guidelines. While RT027 prevalence was moderate, no significant associations with vancomycin or metronidazole resistance were observed. These findings emphasize the need for molecular surveillance and improved antimicrobial stewardship to manage CDI effectively.

The tertiary stage of syphilis appears to be the most diverse of the three recognized, with a number of cardiovascular, gummatous, neurological and psychiatric symptoms. This systematic review’s aim is to analyze cases of organic psychoses secondary to tertiary syphilis, inspect the diagnostic procedures and assess the effectiveness of treatment. Case studies from Pubmed and MEDLINE Ultimate were sought out with the Boolean expression ‘((neurosyphilis) OR (syphilis) OR (treponema pallidum)) AND (case report) AND ((psychosis) OR (psychotic))’ to later undergo screening for exclusion criteria (according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) 2020 guidelines). Each report was accepted independently by two authors. Case reports were later appraised using the JBI Critical Appraisal Checklist for Case Reports. Finally, 11 case reports were included in the study. The most frequently reported psychiatric symptoms were delusions (91%) and hallucinations (81%), disorientation (about 42%) and sleep disturbances and memory loss (36%). Several inconsistencies in diagnostic processes were found in some of the case reports, while treatment procedures were more in line with the guidelines. A disease as complex as neurosyphilis requires great awareness and cooperation between various medical specialties. Despite its mimicry and variability in presentation, the discussed case reports prove that it can be successfully dealt with.