Search Results (7,945)

Acinetobacter baumanni (A. baumannii) is a well-known pathogen associated with antimicrobial-resistant infections. It is a major cause of nosocomial infections and is frequently associated with polymicrobial and antibiotic-resistant infections. This study investigates the frequency of A. baumannii infections, its antimicrobial resistance profile and the main co-pathogens isolated in respiratory samples at the San Giovanni di Dio e Ruggi d’Aragona Hospital in 2015–2019 (pre-COVID-19 pandemic) and 2020–2023 (during/post-COVID-19 pandemic). Bacterial identification and antibiotic susceptibility testing were performed using the VITEK^® 2 system (2015–2019), while identification was carried out with MALDI-TOF MS starting from 2020. A total of 1679 strains were isolated between 2015 and 2019, and 1186 between 2020 and 2023, with significantly higher frequencies in males 61–80 and females 71–80. A. baumannii was isolated predominantly from respiratory specimens, derived predominantly in intensive care units (ICUs). The antimicrobial resistance rates of A. baumannii were above 90% for gentamicin, trimethoprim/sulfamethoxazole, imipenem and ciprofloxacin, while colistin resistance was less than 1% (0.95%) in pre-pandemic and alarmingly increased during/post pandemic period (6.1%). A. baumannii was most frequently associated with Klebsiella pneumoniae, Staphylococcus aureus and Pseudomonas aeruginosa in respiratory tract infections. A. baumannii represents a serious global health threat due to its extensive antimicrobial resistance, highlighting the need for continuous surveillance, detailed strain characterization, and development of new antimicrobial agents. Full article

Background/Objectives: Antimicrobial resistance (AMR) has increased significantly over the years, contributing to a real challenge in the intensive care unit (ICU). The emergence of metallo-beta-lactamases (MBLs) has contributed to the protection of pathogens against all current beta-lactam/beta-lactamase inhibitors (BL/BLIs), including the newer ceftazidime–avibactam (CAZ-AVI), meropenem–vaborbactam, and imipenem–relebactam. Treatment of such infections is challenging. In vitro and clinical data suggest that combinations of CAZ-AVI with aztreonam (ATM) and the use of two different carbapenems (double carbapenem therapy, DCT) may be an option for MBL-producing pathogens. The aim of our study was to evaluate the effectiveness of the combination CAZ-AVI + ATM and the effectiveness of DCT against MBL-producing K. pneumoniae infections in the critically ill, mechanically ventilated patients. Methods: This is a retrospective study conducted in the two ICUs of hospitals in central Greece. Mechanically ventilated patients admitted to the ICU were included in the study if they developed an infection by MBL-producing K. pneumoniae. Patients were divided into three groups: the first one consisted of patients who were treated with CAZ-AVI plus ATM (CAZ-AVI + ATM group), and the second group consisted of patients who received DCT (DCT group). The third group included patients who received appropriate antibiotic therapy other than CAZ-AVI + ATM and DCT (control group). The primary outcome of the study was the evolution of the sequential organ failure assessment (SOFA) score, and secondary outcomes were duration of mechanical ventilation (MV), ICU length of stay (LOS), and, finally, ICU mortality. Results: 108 patients were included in the study. 35 (32%) in the CAZ-AVI + ATM group, 31 (29%) in the DCT group, and the remaining 42 (39%) patients in the control group. The SOFA score was not statistically different on day 1, day 4, and day 7 of the infection among the three groups (p > 0.05). Duration of MV and ICU LOS were also similar. Finally, mortality did not differ between the groups [20 patients (57.1%) vs. 18 (58.1%) vs. 25 (59.5%) for CAZ-AVI + ATM, DCT and control group, respectively, p = 0.98]. Comparison between survivors and non-survivors revealed that independent risk factors for mortality were SOFA score at day 1 of infection and medical cause of admission (p < 0.05). Conclusions: Treatment with CAZ-AVI + ATM or DCT presented similar efficacy with appropriate antibiotic therapy for infections caused by MBL-producing K. pneumoniae strains. Larger studies are required to confirm the findings. Full article

Background/Objectives: Pediatric infectious-disease admissions are common but heterogeneous. We characterized clinical, microbiological, and therapeutic patterns and identified high-risk subgroups relevant to antimicrobial stewardship. Methods: In an observational cohort of 136 children stratified by age, we recorded symptoms, diagnoses, culture results, pathogens, antibiotic therapy, and outcomes. A composite risk score integrating age and clinical/microbiological parameters was assessed. Results: Outcomes were generally favorable: intensive care unit (ICU) transfer 8.8% (95% confidence interval [CI]: 4.6–15.1), mortality 0.7% (95% CI: 0.1–3.9), and median length of stay (LOS) 10 days (interquartile range [IQR] 8–12). Pneumonia was the leading diagnosis (44.9%; 95% CI: 36.3–53.6). Among isolates, Escherichia coli (47.1%) and Klebsiella species (spp.) (27.9%) predominated. Pneumonia correlated with prolonged LOS (p = 0.006), and gastroenteritis with ICU transfer (p = 0.038) and longer LOS (p = 0.018). Mixed E. coli + Klebsiella infections were linked to prolonged stay (p = 0.021). The composite score identified a high-risk stratum with higher ICU transfer (p = 0.004) and prolonged stay (p = 0.006). Conclusions: Although overall outcomes were favorable, risk was not uniform. An age-stratified, multifactorial assessment—integrating clinical presentation, microbiology, and a composite score—identified pediatric subgroups with worse prognoses, supporting targeted monitoring and stewardship-aligned, age-aware empiric therapy. External validation is warranted. Full article

Background: The escalating burden of antimicrobial resistance (AMR) poses a critical threat to public health in Pakistan, with rates of high antibiotic consumption and limited standardized surveillance on AMR rates. Our study aimed to carry out a multicentric surveillance of AMR to generate regional antibiograms for Northern Punjab, Pakistan, to guide empirical antimicrobial therapy and stewardship efforts. Methods: A laboratory-based, retrospective cross-sectional study was conducted over a six-month period across three tertiary care hospitals. Socio-demographic, clinical, and microbiological data (including specimen type and antibiotic prescription rates) were collected from N = 485 patients with confirmed bacterial infections. Antimicrobial susceptibility testing was performed based on Clinical Laboratory Standards Institute (CLSI) recommendations. Statistical analyses were carried out using SPSS v.22.0. Results: In our study setting, Gram-positive bacteria were common causes (60.0%) of infections, with Staphylococcus aureus (12.2%) and Streptococcus pneumoniae (10.3%) being the most relevant. Among Gram-negative bacteria (40.0%), Escherichia coli (14.0%) and Pseudomonas aeruginosa (5.8%) were shown to be important pathogens. Overall, 25.0% of S. aureus isolates were methicillin-resistant (MRSA), while ~30% of E. coli showed resistance to third-generation cephalosporins (3GCs). Enterobacterales species had highly variable susceptibility rates (40–70%) for fluoroquinolones. Meropenem and vancomycin/linezolid retained high efficacy (>90%) against most Gram-negative and Gram-positive isolates, respectively. In all healthcare settings studied, ceftriaxone was the most frequently prescribed antibiotic. Conclusions: High levels of resistance against first-line antibiotics were noted in our setting of Northern Punjab, Pakistan, underscoring the critical need for robust antimicrobial stewardship programs, tailored to local institutional contexts, capabilities, and needs. The regional antibiogram developed based on our data may provide vital evidence for informing local empirical treatment guidelines, which need to be continuously updated. Full article

Background/Objectives: Klebsiella pneumoniae is a clinically important pathogen that causes respiratory tract infections, pneumonia, wound infections, urinary tract infections, and sepsis. It is on the World Health Organization (WHO) priority pathogen list as it causes antimicrobial-resistant infections. The aim of this study was to isolate bacteriophages against pan-resistant K. pneumoniae isolated from clinical wound infections. Results: One of the isolated phages, CTF-1, possesses a linear double-stranded DNA genome that is 40,841 base pairs (bp) long and contains 44 predicted genes. Functional assignments were made for 31 of the predicted gene products, which are associated with genome replication, phage packaging, structural proteins, and host lysis, leaving 13 annotated as hypothetical proteins. Based on sequencing analysis, phage CTF-1 is a new member of the genus Przondovirus within the order Autographivirales. Phage CTF-1 was effective against 22 of 25 (88%) pan-resistant K. pneumoniae isolates. The latent period and lytic cycle of the phage were approximately 40 min, with a burst size of about 92 PFU/mL. Conclusions: Our findings suggest that Klebsiella phage CTF-1 is an excellent candidate for phage therapy due to its high lytic activity against pan-resistant K. pneumoniae strains and lack of genes encoding antibiotic resistance, toxins, virulence factors, or integrases. Full article

The nucleoid-associated protein Fis functions as a global regulator that influences various cellular processes in Gram-negative bacteria. In this study, we examined the role of Fis in the transcriptional regulation of type 3 fimbriae in Klebsiella pneumoniae, a notable opportunistic pathogen associated with hospital-acquired infections. Our transcriptional analyses revealed that deleting the fis gene caused a significant upregulation of mrkA and mrkH, the genes responsible for the structure and regulation of type 3 fimbriae, respectively. Additionally, phenotypic assays demonstrated that the Δfis mutant exhibited enhanced biofilm formation and greater adherence to A549 lung epithelial cells compared to the wild-type strain. These effects were restored to wild-type levels in the cis-complemented strain. Electrophoretic mobility shift assays confirmed that Fis directly binds to the regulatory regions upstream of both mrkA and mrkH, indicating that repression occurs through direct interaction with the promoter. In summary, our findings show that Fis acts as a transcriptional repressor of mrkA and mrkH, thereby negatively regulating the expression of type 3 fimbriae, biofilm formation, and adherence. This study highlights Fis as a direct regulator of fimbrial expression and biofilm development in K. pneumoniae, deepening our understanding of its virulence regulatory network. Full article

This study developed a rapid and reliable SYBR-Green semiplex PCR assay for simulta-neous detection of major carbapenem resistance genes in Klebsiella pneumoniae and Acinetobacter baumannii. Two primer sets were used: one to detect blaKPC, blaNDM-1, and blaOXA-48 genes in K. pneumoniae and blaOXA-23 in A. baumannii, and another to amplify conserved 16S rRNA gene regions as internal controls. The intra- and inter-assay coeffi-cient of variation ranged from 0.03% to 3.8%. Standard curves exhibited excellent linearity across six logarithmic scales (10¹–10⁶ DNA copies/µL), with detection limits of 10–10² DNA copies/mL. Melting temperatures (Tm) were: 88.85 °C (KPIC), 90.65 °C (NDM-1), 89.45 °C (KPC), 84.23 °C (OXA-48), 87.81 °C (OXA-23), and 80.67 °C (ABIC). The SYBR-Green Semiplex PCR assay offers a rapid (65 min turnaround), cost-effective, and sensitive method for early detection of carbapenem-resistant pathogens, enabling timely targeted therapy and improved infection control by potentially reducing empirical antibiotic use before culture confirmation. Full article

Background: Urinary tract infections (UTIs) are the most common infections among kidney transplant recipients, with prevalence rates ranging from 12% to 75% in studies from North America and Australia and from 4.5% to 85% in the Middle East. These infections can significantly impact graft survival and patient quality of life, increasing the risk of hospitalization, morbidity, and mortality. Escherichia coli is the leading cause of UTIs in transplant patients, but multidrug-resistant (MDR) pathogens are a growing concern, especially in Saudi Arabia. Several factors, including advanced age, female gender, and use of urinary catheters, contribute to post-transplant UTIs. This study focuses on the Saudi population, aiming to assess the prevalence, risk factors, and treatment strategies for recurrent and multidrug-resistant UTIs in kidney transplant recipients. Methods: This retrospective cohort study reviewed the medical records of kidney transplant patients at King Faisal Specialist Hospital & Research Center, Jeddah, in addition to data from King Fahad Hospital, Madinah, Saudi Arabia, between March and May 2022. Adult patients (≥18 years) who developed recurrent UTIs within two years post-transplant were included, while those with one or no UTI episode or incomplete records were excluded. Results: Seventy-five of 491 screened patients (15.3%) experienced recurrent UTIs, contributing to a total of 219 episodes. Klebsiella pneumoniae was the most frequent pathogen, isolated in 94 episodes (42.9%). Key risk factors for recurrence included complicated UTIs (OR = 4.60, p = 0.005), multidrug-resistant organisms (MDROs) (OR = 3.14, p = 0.021), and ureteric stents (OR = 4.07, p = 0.042). Carbapenems were primarily used for complicated UTIs, while cephalosporins and penicillins were used for uncomplicated infections. A significant post-UTI rise in serum creatinine was observed (p < 0.001). Conclusions: Recurrent UTIs predominantly caused by K. pneumoniae are common in kidney transplant recipients, particularly in patients over 45, with multidrug-resistant organisms, or with ureteric stents. While a direct causal link to graft loss was not established, these infections can lead to increased creatinine levels, hospitalizations, and healthcare costs and increased carbapenem use. These findings highlight the critical need for institution-specific antimicrobial stewardship programs focused on infection prevention and optimized antibiotic use to improve outcomes in this vulnerable population. Full article

Multidrug-resistant (MDR) bloodstream infections (BSIs) constitute a major challenge in intensive care units, with the COVID-19 pandemic compromising infection control and potentially increasing MDR incidence. Comparative data between COVID and non-COVID ICU populations remain limited. The MARTINI study is a retrospective observational analysis held in a tertiary hospital during the COVID-19 pandemic (2020–2022) encompassing adult patients with MDR BSIs admitted to COVID and non-COVID ICUs. Demographics, comorbidities, severity scores, microbiology, resistance patterns, and outcomes were accessed and compared. A binary logistic regression model and multivariate regression was performed to identify independent predictors of ICU mortality. Among the study’s 156 patients (106 COVID-ICU, 50 non-COVID-ICU), COVID-ICU patients were significantly older with higher comorbidity and severity scores. Gram-negative pathogens predominated in both cohorts, mainly Acinetobacter baumannii and Klebsiella pneumoniae, with comparable resistance mechanisms. Timing of bacteremia onset and initiation of appropriate therapy did not differ between groups. However, ICU mortality was markedly higher in COVID-ICU patients (74.5% vs. 38%, p < 0.001). Age, SOFA score, the presence of systemic inflammation (SIRS) and COVID-19 infection were identified as independent predictors of mortality. Although pathogen distribution and resistance were similar across groups, COVID-ICU patients experienced significantly poorer outcomes. Strengthened infection control and timely and targeted antimicrobial therapy are essential to diminish MDR bacteremia risk in critically ill populations. Full article

Background: The intersection between oncology and intensive care has shifted from predominantly end-of-life care to a therapeutic bridge that can preserve anticancer trajectories in carefully selected patients. Yet, criteria separating benefit from futility remain fragmented. Objective: This paper seeks to map contemporary evidence (2015–2025) on outcomes after Intensive Care Unit (ICU) admission in adults with cancer and to identify clinical constellations in which ICU-level care still changes prognosis. Methods: PRISMA-ScR scoping review (PCC framework). PubMed search (2015–2025), dual screening, standardized extraction; narrative/thematic synthesis across six clusters (hematologic, solid tumors, sepsis/non-COVID-19 infection, COVID-19/viral pneumonia, novel/targeted-therapy toxicities, end-of-life/aggressive ICU) were used. No meta-analysis given heterogeneity. Results: Seventy-three studies (>170,000 ICU admissions) were included, mostly cohort designs across 27 countries. ICU mortality ranged 8–72% (weighted mean ≈ 41%); hospital ≈ 38%; 90-day ≈ 46%; 1-year ≈ 62%. About one third of ICU survivors resumed systemic therapy. Benefit concentrated in early admissions, single-organ failure, controlled/remission disease, postoperative/elective monitoring, and reversible treatment-related toxicities (e.g., ICI pneumonitis, CAR-T CRS/ICANS). Futility clustered around ≥3 organ supports, RRT > 7 days, refractory/progressive disease, and ECOG ≥ 3. Sepsis outcomes averaged 45–55% ICU mortality but improved with rapid recognition and source control; COVID-19 mortality was particularly high in hematologic malignancies early in the pandemic, with subsequent declines post-vaccination. Conclusions: In modern oncologic practice, ICU care changes prognosis when the acute physiological insult is reversible and cancer control remains plausible; conversely, high organ-support burden and refractory disease define practical futility thresholds. These signals support time-limited ICU trials, earlier ICU involvement for sepsis/irAEs, and embedded palliative care to align intensity with goals. Full article

We report the case of a 42-year-old, non-smoking male admitted with right upper-lobe pneumonia. Chest computed tomography (CT) demonstrated findings consistent with an infectious process. For further evaluation, serial bronchoscopies with biopsy sampling were performed. Histopathological examination revealed moderate squamous dysplasia of the tracheal epithelium, and subsequent immunohistochemical testing detected human papillomavirus (HPV) genotype 45. This case underscores the value of integrating imaging, endoscopic assessment, and molecular diagnostic techniques in the evaluation of atypical pulmonary lesions and highlights the potential role of HPV infection in airway epithelial dysplastic changes. Full article

Early diagnosis and rapid treatment of respiratory abnormalities such as many lung diseases including pneumonia, TB, cancer, and other pulmonary problems depend on accurate and fast classification of chest X-ray images. Delayed diagnosis and insufficient treatment lead to the subjective, labour-intensive, error-prone features of current manual diagnosis systems. To tackle this pressing healthcare issue, this work investigates many deep convolutional neural network (CNN) architectures including VGG16, VGG19, ResNet50, InceptionV3, Xception, DenseNet121, NASNetMobile, and NASNet Large. LungVisionNet (LVNet) is an innovative hybrid model proposed here that combines MobileNetV2 with multilayer perceptron (MLP) layers in a unique way. LungVisionNet outperformed previous models in accuracy 96.91%, recall 97.59%, precision, specificity, F1-score 97.01%, and area under the curve (AUC) measurements according to thorough examination on two publicly available datasets including various chest abnormalities and normal cases exhibited. Comprehensive evaluation with an independent, real-world clinical dataset from King Hussein Cancer Centre (KHCC), which achieved 95.3% accuracy, 95.3% precision, 78.8% recall, 99.1% specificity, and 86.4% F1-score, confirmed the model’s robustness, generalizability, and clinical usefulness. We also created a simple mobile application that lets doctors quickly classify and evaluate chest X-ray images in hospitals, so enhancing clinical integration and practical application and supporting fast decision-making and better patient outcomes. Full article

Background/Objectives: Klebsiella pneumoniae ST258 and ST11 are global high-risk antimicrobial-resistant clones known for their virulence and resistance gene dissemination. This study aims to identify these clones in a Greek tertiary hospital and understand their resistance profiles and transmission dynamics. Methods: In January 2025, we isolated two distinct carbapenem-resistant K. pneumoniae in a Greek tertiary hospital: INT18S from an ICU patient’s bronchioalveolar lavage and INT20U from a urine sample in the emergency unit. Antimicrobial susceptibility testing (via Microscan system) and Whole-Genome Sequencing (WGS) were conducted on both isolates and their genomes were submitted to the NCBI. Results: The INT18S isolate carried the bla_KPC-2 gene and belonged to the ST258 clone. The INT20U isolate carried the bla_NDM-1 gene and belonged to the ST11 clone lineage. Both isolates contained at least one of the extended spectra β-lactamase genes tested (TEM, SHV, OXA-1 and CTX-M group). Conclusions: The co-existence of the high-risk K. pneumoniae clones ST258 and ST11 in different hospital departments increases the risk of resistance gene transfer and suggests potential intra-hospital transmission pathways. Understanding their resistance profiles is critical for guiding treatment strategies and preventing the spread of multidrug-resistant pathogens. Full article

Background/Objectives: Antimicrobial resistance (AMR) in Klebsiella pneumoniae poses a serious threat to healthcare, especially in sub-Saharan Africa (SSA). To complement AMR infection control in Kenya, here, clinical and environmental genomes were investigated to determine the potential roles prophages play in K. pneumoniae pathogenicity. Methods: Prophages were extracted from 89 Kenyan K. pneumoniae genomes. The intact prophages were examined for virulence genes carriage, and their phylogenetic relationships were established. Results: Eighty-eight (~99%) of the genomes encode at least a single prophage, and there is an average of four prophages and 2.8% contributory genomes per bacterial strain. From the 364 prophages identified, 250 (68.7%) were intact, while 58 (15.9%) and 57 (15.7%) were questionable and incomplete, respectively. Approximately, 30% of the intact prophages encode 38 virulence genes that are linked to iron uptake (8), regulation (6), adherence (5), secretion system (4), antiphagocytosis (4), autotransporter (4), immune modulation (3), invasion (2), toxin (1) and cell surface/capsule (1). Phylogenetic analyses revealed three distinct clades of the intact prophages irrespective of their hosts, sources and locations, which support the plasticity of the genomes and potential to mediate horizontal gene transfer. Conclusions: This study provides first evidence showing the diverse prophages that are encoded in K. pneumoniae from SSA with particular focus on Kenyan strains. This also shows the potential roles these prophages play in the pathogenicity and success of K. pneumoniae and could improve knowledge and complement control strategies in the region and across the globe. Further work is needed to show the expression of these genes through lysogenisation. Full article

Essential oils (EOs) are complex plant-derived products known for their broad-spectrum antibacterial activity. This study aims to evaluate the chemical composition of eight essential oils-EOs (Caryophylli aetheroleum, Menthae aetheroleum, Origani aetheroleum, Rosmarini aetheroleum, Salviae aetheroleum, Melaleucae aetheroleum, Limonis aetheroleum, and Curcumae aetheroleum) and to evaluate their antibacterial and antibiofilm activity against five opportunistic pathogens with biofilm-forming potential (methicillin-susceptible and methicillin-resistant Staphylococcus aureus, Pseudomonas aeruginosa, Enterococcus faecalis, Escherichia coli, and Klebsiella pneumoniae). GC-MS was used to determine the chemical composition of the EOs, and antibacterial activity was evaluated using broth microdilution to determine the minimum inhibitory concentration and minimum bactericidal concentration. Biofilm inhibition was assessed by a crystal violet assay. Oxygenated monoterpenes and phenolic compounds were dominant in Origani, Menthae, Rosmarinus, Melaleucae, and Caryophylli aetheroleum. Potent inhibitory effects against the tested bacterial strains were observed for clove, tea tree, oregano, and rosemary EOs. The antimicrobial efficacy of EOs is closely linked to their chemical composition. Tea tree and oregano EOs exhibited the broadest spectrum of antimicrobial activity, while peppermint and curcuma oils were the least potent. Cytotoxicity thresholds from the literature suggest that some effective EO concentrations exceed safe mucosal limits, particularly in continuous high-dose applications, but short-contact delivery systems or adjunctive use with different agents may mitigate safety concerns. These findings support further investigation into their therapeutic applications in oral health products. Full article