Search Results (912)

Antibiotic-resistant Pseudomonas aeruginosa presents a critical global health challenge, particularly in hospital-acquired infections. Bacteriophages offer a promising therapeutic avenue due to their ability to target and lyse resistant strains. This study characterizes Pseudomonas phage Banzai, a newly isolated Pbunavirus (family Lindbergviridae) with lytic activity against multiple P. aeruginosa isolates, including multidrug-resistant strains. Genomic analysis revealed a 66,189 bp genome, lacking antibiotic resistance or virulence factors, and suggested a headful packaging mechanism and the presence of a bidirectional component in the replication. In vivo experiments using Galleria mellonella showed therapeutic potential, significantly improving larval survival (87% at 24 h). Host range analysis revealed activity against 13 of 30 P. aeruginosa isolates, including members of O1, O3, O5 and O6 in silico predicted serogroups. Phylogenomic analyses place phage Banzai within the genus Pbunavirus, sharing 94.8% intergenomic similarity with its closest relatives, supporting its classification as a novel species. These findings highlight phage Banzai as a potential candidate for phage therapy, demonstrating genomic stability, a strictly lytic lifestyle, and in vivo efficacy. Full article

Ceftazidime–avibactam (CAZ-AVI) is a second-generation intravenous β-lactam/β-lactamase inhibitor combination. In recent years, substantial evidence has emerged regarding the efficacy and safety of CAZ-AVI. However, data on its use in critically ill patients remain limited. Background/Objectives: This multicenter, retrospective, observational cohort study was conducted across four Intensive Care Units (ICUs) in three hospitals in the Marche region of Italy. The primary objective was to evaluate the 30-day clinical outcomes and identify risk factors associated with 30-day clinical failure—defined as death, microbiological recurrence, or persistence within 30 days after discontinuation of therapy—in critically ill patients treated with CAZ-AVI. Methods: The study included all adult critically ill patients admitted to the participating ICUs between January 2020 and September 2023 who received CAZ-AVI for at least 72 h for the treatment of a confirmed or suspected Gram-negative bacterial (GNB) infection. Results: Among the 161 patients included in the study, CAZ-AVI treatment resulted in a positive clinical outcome (i.e., clinical improvement and 30-day survival) in 58% of cases (n = 93/161), while the overall mortality rate was 24% (n = 38/161). Relapse or persistent infection occurred in a substantial proportion of patients (25%, n = 41/161). Notably, acquired resistance to CAZ-AVI was observed in 26% of these cases, likely due to suboptimal use of the drug in relation to its pharmacokinetic/pharmacodynamic (PK/PD) properties in critically ill patients. Furthermore, treatment failure was more frequent among immunosuppressed individuals, particularly liver transplant recipients. Conclusions: This study demonstrates that the mortality rate among ICU patients treated with this novel antimicrobial combination is consistent with findings from other studies involving heterogeneous populations. However, the rapid emergence of resistance underscores the need for vigilant surveillance and the implementation of robust antimicrobial stewardship strategies. Full article

Background/Objectives: This study aimed to create a ‘carbapenem resistance score’ with the risk factors of carbapenem-resistant Gram-negative bacterial infections (GNBIs) in patients with hematological malignancies. Methods: Patients with carbapenem-resistant and susceptible GNBIs were included in this study and compared in terms of risk factors. Three models of “carbapenem resistance risk scores” were created with statistically significant variables. Results: The study included 154 patients with hospital-acquired GNBIs, of whom 64 had carbapenem-resistant GNBIs and 90 had carbapenem-susceptible GNBIs. Univariate and multivariate analyses identified several statistically significant risk factors for carbapenem resistance, including transfer from another hospital or clinic (p = 0.038), prior use of antibiotics like fluoroquinolones (p = 0.009) and carbapenems (p = 0.001), a history of carbapenem-resistant infection in the last six months (p < 0.001), rectal Klebsiella pneumoniae colonization (p < 0.001), hospitalization for ≥30 days (p = 0.001), and the presence of a urinary catheter (p = 0.002). Notably, the 14-day mortality rate was significantly higher in the carbapenem-resistant group (p < 0.001). Based on these findings, three risk-scoring models were developed. Common factors in all three models were fluoroquinolone use in the last six months, rectal K. pneumoniae colonization, and the presence of a urinary catheter. The fourth variable was transfer from another hospital (Model 1), a history of carbapenem-resistant infection (Model 2), or hospitalization for ≥30 days (Model 3). All models demonstrated strong discriminative power (AUC for Model 1: 0.830, Model 2: 0.826, Model 3: 0.831). For all three models, a cutoff value of >2.5 was adopted as the threshold to identify patients at high risk for carbapenem resistance, a value which yielded high positive and negative predictive values. Conclusions: This study successfully developed three practical risk-scoring models to predict carbapenem resistance in patients with hematological malignancies using common clinical risk factors. A cutoff score of >2.5 proved to be a reliable threshold for identifying high-risk patients across all models, providing clinicians with a valuable tool to guide appropriate empirical antibiotic therapy. Full article

Acinetobacter baumannii is a multidrug-resistant bacterium that has gained significant attention in recent years due to its involvement in a growing number of hospital-acquired infections. The World Health Organization has classified it as a critical priority pathogen, underscoring the urgent need for new therapeutic strategies. Post-translational modifications (PTMs), such as phosphorylation, play essential roles in various bacterial processes, including antibiotic resistance, virulence or biofilm formation. Although proteomics has increasingly enabled their characterization, the identification of phosphorylated peptides remains challenging, primarily due to the enrichment procedures. In this study, we focused on characterizing serine, threonine, and tyrosine phosphorylation in the A. baumannii ATCC 17978 strain. We optimized three parameters for phosphopeptide enrichment using titanium dioxide (TiO₂) beads (number of enrichment fractions between the phosphopeptides and TiO₂ beads, the quantity peptides and type of loading buffer) to determine the most effective conditions for maximizing phosphopeptide identification. Using this optimized protocol, we identified 384 unique phosphorylation sites across 241 proteins, including 260 novel phosphosites previously unreported in A. baumannii. Several of these phosphorylated proteins are involved in critical bacterial processes such as antimicrobial resistance, biofilm formation or pathogenicity. We discuss these proteins, focusing on the potential functional implications of their phosphorylation. Notably, we identified 34 phosphoproteins with phosphosites localized at functional sites, such as active sites, multimer interfaces, or domains important for structural integrity. Our findings significantly expand the current phosphoproteomic landscape of A. baumannii and support the hypothesis that PTMs, particularly phosphorylation, play a central regulatory role in its physiology and pathogenic potential. Full article

Determining the optimal duration of antibiotic therapy for infections caused by multidrug-resistant Gram-negative bacteria (MDR-GNB) is a critical challenge in clinical medicine, balancing therapeutic efficacy against the risks of adverse effects and antimicrobial resistance. This narrative review synthesises current evidence and guidelines regarding antibiotic duration for MDR-GNB infections, emphasising bloodstream infections (BSI), hospital-acquired and ventilator-associated pneumonia (HAP/VAP), complicated urinary tract infections (cUTIs), and intra-abdominal infections (IAIs). Despite robust evidence supporting shorter courses (3–7 days) in uncomplicated infections caused by more susceptible pathogens, data guiding optimal therapy duration for MDR-GNB remain limited, particularly concerning carbapenem-resistant Enterobacterales (CRE), difficult-to-treat Pseudomonas aeruginosa (DTR-Pa), and carbapenem-resistant Acinetobacter baumannii (CRAB). Current guidelines from major societies, including IDSA and ESCMID, provide explicit antimicrobial selection advice but notably lack detailed recommendations on the duration of therapy. Existing studies demonstrate non-inferiority of shorter versus longer antibiotic courses in specific clinical contexts but frequently exclude critically ill patients or those infected with non-fermenting MDR pathogens. Individualised duration decisions must integrate clinical response, patient immunologic status, infection severity, source control adequacy, and pharmacologic considerations. Significant knowledge gaps persist, underscoring the urgent need for targeted research, particularly randomised controlled trials assessing optimal antibiotic duration for the most challenging MDR-GNB infections. Clinicians must navigate considerable uncertainty, relying on nuanced judgement and close monitoring to achieve successful outcomes while advancing antimicrobial stewardship goals. Full article

Pseudomonas aeruginosa is a highly adaptable opportunistic pathogen with significant clinical relevance in both human and veterinary medicine. Despite its well-documented role in hospital-acquired infections in human healthcare settings, its persistence and transmission within veterinary clinics remain underexplored. This review highlights the overlooked status of veterinary facilities as environmental reservoirs and amplification points for multidrug-resistant (MDR) P. aeruginosa, emphasizing their relevance to One Health surveillance. We examine the bacterium’s environmental survival strategies, including biofilm formation, resistance to disinfectants, and tolerance to nutrient-poor conditions that facilitate the long-term colonization of moist surfaces, drains, medical equipment, and plumbing systems. Common transmission vectors are identified, including asymptomatic animal carriers, contaminated instruments, and the hands of veterinary staff. The review synthesizes current data on antimicrobial resistance in environmental isolates, revealing frequent expression of efflux pumps and mobile resistance genes, and documents the potential for zoonotic transmission to staff and pet owners. Key gaps in environmental monitoring, infection control protocols, and genomic surveillance are identified, with a call for standardized approaches tailored to the veterinary context. Control strategies, including mechanical biofilm disruption, disinfectant cycling, effluent monitoring, and staff hygiene training, are evaluated for feasibility and impact. The article concludes with a One Health framework outlining cross-species and environmental transmission pathways. It advocates for harmonized surveillance, infrastructure improvements, and intersectoral collaboration to reduce the risk posed by MDR P. aeruginosa within veterinary clinical environments and beyond. By addressing these blind spots, veterinary facilities can become proactive partners in antimicrobial stewardship and global resistance mitigation. Full article

Antibiotic resistance and biofilm formation complicate Staphylococcus aureus infections, raising concerns for global health. Understanding antimicrobial resistance and biofilm formation in these pathogens is essential for effective infection management. The current research aimed to assess antibiotic resistance patterns, biofilm formation, and the occurrence of integron classes 1, 2, and 3 in clinical S. aureus isolates. The disc diffusion method tested antibiotic susceptibility. MRSA strains were identified by cefoxitin disc diffusion, and the mecA gene by PCR. The D-test also assessed macrolide–lincosamide–streptogramin B. A microtiter plate assay assessed biofilm formation. By PCR, integron classes were examined. Of the 63 S. aureus isolates, 25 were MSSA and 38 were MRSA. Pus (39.5%) was the most prevalent clinical source of MRSA isolates, while blood (24%) was the predominant source of MSSA isolates. MRSA isolates were more resistant to clindamycin, ciprofloxacin, ofloxacin, levofloxacin, tetracycline, and doxycycline than MSSA isolates. In total, 76.2% of the isolates produced biofilm. Biofilm-producing isolates were more resistant to cefoxitin and clindamycin. The isolates had 33.3% cMLSB resistance. The intI1 gene was found in 21 S. aureus isolates (33.3%), whereas the intI2 or intI3 genes were not detected. Our findings demonstrate the need for strict infection control to prevent the spread of resistant bacteria. Full article

Objective: This study aimed to assess the effect of antibiotic de-escalation on 30-day mortality, duration of intravenous (IV) antibiotic therapy and length of hospital stay (LOS) in severe community-acquired pneumonia (sCAP). Methods: We performed a retrospective analysis of prospectively collected data from a cohort of adults diagnosed with sCAP and microbiologically confirmed etiology between 1995 to 2022. Two distinct time points of the de-escalation were analyzed: 3 and 6 days post-admission, corresponding, respectively, to the availability of microbiological results and the median time to clinical stability. Inverse propensity score-weighted binary logistic regression was used to adjust for potential confounders. Results: A total of 398 consecutive cases of sCAP were analyzed. No significant differences were observed between the de-escalation and non-de-escalation groups in terms of age, sex, comorbidities, or severity-related variables (such as impaired consciousness, shock, respiratory failure, or multilobar pneumonia). Patients in the de-escalation group had lower rates of leukopenia, bacteremia and empyema, and less need for mechanical ventilation, with variations depending on the timing of de-escalation. After adjusting for confounding factors in an inverse propensity score-weighted analysis, de-escalation within 3 or 6 days after admission was not associated with increased mortality risk (adjusted odds ratio [aOR] 1.48, 95% confidence interval [CI] 0.29–7.4; p = 0.63, and aOR 0.57, 95% CI 0.14–2.31, p = 0.43, respectively). Similar findings were observed for prolonged LOS. However, antibiotic de-escalation was related to a lower risk of prolonged IV antibiotic. Conclusions: Antibiotic de-escalation in microbiologically confirmed sCAP did not negatively impact clinical outcomes, supporting the safety of this strategy for optimizing antibiotic use in this serious infection. Full article

Urogenital infections contribute greatly to both hospital- and community-acquired infections. In Ghana, the prevalence of resistance to commonly used antibiotics is relatively high. This study sought to evaluate the antibiotic sensitivity of bacterial urogenital pathogens from patient samples in a regional and district hospital in the Volta Region of Ghana. A retrospective cross-sectional study was conducted using data obtained between January and December 2023 from Volta Regional Hospital and Margret Marquart Catholic Hospital. Bacteria were isolated from urine, urethral swabs, and vaginal swabs from 204 patients. Data on culture and sensitivity assays performed using the Kirby–Bauer disc diffusion method were extracted and analyzed using WHONET. The most prevalent organisms isolated from the samples from both facilities were Escherichia coli (24.9%), Staphylococcus aureus (21.5%), and Klebsiella oxytoca (8.8%). The isolates were mostly resistant to amoxicillin/clavulanic acid (n = 75, 95% CI [91.8–99.9]), meropenem (n = 61, 95% CI [87.6–99.4]), cefuroxime (n = 54, 95% CI [78.9–96.5]), ampicillin (n = 124, 95% CI [61.2–77.9]), and piperacillin (n = 43, 95% CI [82.9–99.2]). Multidrug-resistant (MDR, 70 (34.1%)), extensively drug-resistant (XDR, 63 (30.7%)), and pandrug-resistant (PDR, 9 (4.3%)) strains of S. aureus, E. coli, and Pseudomonas aeruginosa were identified from the patient samples. The study highlights the presence of high-priority resistant urogenital pathogens of public health significance to varied antibiotic groups. Full article

This review aims to summarize the global prevalence of healthcare-associated infections in patients with acute heart failure who have been admitted to coronary care units, highlighting the underrepresented burden of infection in this high-risk population. Coronary care units (CCUs) play a pivotal role in the care of patients experiencing acute or decompensated heart failure, offering a highly monitored environment with immediate access to advanced cardiac interventions. The management of heart failure in CCUs involves a multidisciplinary approach that includes hemodynamic monitoring, pharmacologic therapy, respiratory support, and, in selected cases, mechanical circulatory assistance. The early identification of deterioration, rapid therapeutic escalation, and close monitoring of cardiac function are hallmarks of CCU care. However, the complexity and severity of illness in this population are compounded by a high risk of infections, including hospital-acquired pneumonia, bloodstream infections, and device-related infections. These infections not only increase morbidity and prolong hospitalization but also significantly impact mortality and healthcare costs. The immunocompromised state of many heart failure patients—due to poor perfusion, malnutrition, and the use of invasive devices—further elevates their vulnerability. Effective infection prevention, early diagnosis, and targeted antimicrobial therapy are, therefore, critical components of heart failure management within CCUs. This intersection of advanced cardiac care and infection control highlights the need for integrated, multidisciplinary strategies to improve outcomes in this high-risk population. Full article

Background: Clostridioides difficile infection (CDI) is a major concern in hospital-acquired infections. C. difficile spores can survive on surfaces for months and require sporicidal disinfection for elimination. The use of disinfectants should be based on laboratory-confirmed sporicidal activity, tested according to current standards in suspension and carrier tests. Further evaluation of disinfectant efficacy should occur in clinical settings by analyzing reductions in CDI incidence. This study aims to conduct a retrospective analysis of the impact of a new disinfection protocol and concurrent changes in antibiotic consumption on the incidence of healthcare-acquired CDI (HA-CDI). Methods: This retrospective, single-center study assessed the impact of a chlorine dioxide-based disinfection protocol on HA-CDI across three periods: pre-intervention, intervention, and post-intervention. An interrupted time series analysis (ITS) with a Poisson distribution was used to evaluate the incidence of HA-CDI, while antibiotic consumption data were analyzed to identify any correlation with CDI infection rates. Results: Incidence Rate Ratio (IRR) before the intervention is 1.00, serving as the reference value. During the intervention period, the IRR is 0.79 (95% CI: 0.42–1.36; p = 0.43), indicating a decrease in the incidence of infections compared to the pre-intervention period, although this result is not statistically significant. After the intervention, the IRR is 0.53 (95% CI: 0.26–0.97; p = 0.057), suggesting a further reduction in the incidence of CDI; this result is on the borderline of statistical significance (p = 0.057), indicating a potential effect of the intervention, albeit without full statistical certainty. Conclusions: The absence of a CDI surge despite increased antibiotic consumption highlights the synergistic relationship between antibiotic stewardship and rigorous infection control practices. The combination of the improved disinfection protocol and comprehensive staff training proved remarkably effective in mitigating CDI risk. Cleaning and disinfection in healthcare facilities is crucial for the prevention of healthcare-associated infections. Full article

Leuconostoc spp. are vancomycin-resistant Gram-positive cocci that are used in food production and as pre- and probiotics. However, Leuconostoc spp. can also cause infections. In the present study, the records of patients with Leuconostoc spp. detection between January 2012 and March 2025 were analyzed, inclusive of the underlying risk factors. Leuconostoc spp. was isolated from 32 patients (21 male, 11 females), including nine patients with blood culture evidence. In the majority of patients, Leuconostoc spp. were obtained on the day of admission to the hospital or in the first few days thereafter, arguing against nosocomial acquisition. The median age of men and women (65.3 and 67.8 years) was similar, but seven of the 14 male patients over the age of 65 had the bacteria in blood culture. The female patients with blood culture evidence had suffered from peripartum thrombophlebitis and from anorexia nervosa (BMI 8.8 kg/m²). In contrast, men with Leuconostoc spp. in the blood culture had severe, limiting underlying diseases. While the two women survived, five of the seven blood-culture-positive men died. Overall, our results show that Leuconostoc spp. is mainly acquired in outpatient settings, but men are at a higher risk of acquisition. Colonized men over the age of 60 with severe underlying diseases have a high risk of systemic infection with a fatal outcome. Full article

Healthcare-associated infections (HAIs), also referred to as nosocomial or hospital-acquired infections, are a significant cause of death worldwide, with hand hygiene being the most powerful means to tackle them. The present study had a twofold aim: first, to assess the level of knowledge and the degree of compliance with hand hygiene practices based on healthcare workers’ self-reports; second, to evaluate whether behavioral economics techniques, specifically a poster combining an image and an informational message, designed according to the published literature, can increase the level of healthcare workers’ compliance with hand hygiene. Factors that potentially affect compliance were also examined. This study involved distributing a questionnaire to healthcare workers in Greek public hospitals, from which 314 completed responses were collected during the last quarter of 2023. Participants were randomly and evenly assigned to an intervention group that received a nudging poster or to a control group, which did not. Self-reported compliance with hand hygiene practices was high, based on two latent variables derived through exploratory factor analysis, although knowledge of germ transmission was moderate, as reflected in the relevant knowledge question scores. However, nudging had no statistically significant effect on hand hygiene behavior. Compliance was associated with several factors, including gender, age, work experience, profession, perceived adequacy of available hygiene-related resources, and perceived consequences of nosocomial infections on patient outcomes. Full article

Background: Hospitalized COVID-19 patients are particularly vulnerable to secondary bacterial infections, which can significantly worsen clinical outcomes. The aim of the study was to identify the cause of bacteremia in a group of hospitalized COVID-19 patients and find out the source of the outbreak to prevent further spread. Methods: Pathogen identification in blood cultures and sensitivity testing were carried out using the automated VITEK2 system. A total of 110 samples were tested; these were collected from patients’ colonization sites and from surfaces, materials and fluids used in the setting. Furthermore, multilocus sequence typing (MLST) and next-generation sequencing (NGS) were employed to characterize the isolates. Results: Achromobacter xylosoxidans was detected in the blood of nine hospitalized patients and in cotton used for disinfection; all isolates presented an identical antibiotic resistance pattern, and all carried the bla_OXA-114 gene which is intrinsic to this species. Infection control measures were implemented promptly. With one exception, all patients recovered and were discharged in good health. Conclusions: This outbreak underscores the urgent need for investigation and control of hospital infections, as bacteremia is associated with increased morbidity, mortality, hospitalization time, and cost. It also highlights the importance of close collaboration among healthcare professionals. Full article

Background: Enterobacterales are among the most frequent causes of healthcare-associated infections and are increasingly affected by antimicrobial resistance. Antibiotic use disrupts the gut microbiota, facilitating colonization by multidrug-resistant organisms, including carbapenemase-producing Enterobacterales (CPE). While animal studies have suggested that certain antibiotic classes may increase the risk of CPE acquisition, clinical data identifying which classes are most implicated remain limited. Methods: We conducted a single-center, retrospective case-control study (2021–2024) comparing antibiotic prescriptions in patients who acquired CPE with those in controls hospitalized in the same unit and during the same risk period but who did not acquire CPE. The objective of this study was to identify which antibiotic classes or pharmacological properties are associated with the acquisition of carbapenemase-producing Enterobacterales (CPE) in hospitalized patients. Results: During the study period, 35 cases and 70 controls were included. Most cases acquired NDM-type metalloenzymes. Before the risk period, 55 patients had received antibiotic therapy. Univariate analysis identified an association between CPE acquisition and the prescription of fluoroquinolones and antibiotics excreted in bile. During the risk period, only metronidazole prescription was significantly associated with CPE acquisition. Our study has several limitations, including the small sample size, the single-center retrospective design, and the lack of molecular typing (e.g., WGS) to confirm potential clonal transmission. Conclusions: In this preliminary study, metronidazole use was associated with an increased risk of CPE acquisition during risk periods. However, these results should be interpreted cautiously and need to be confirmed in larger, multicenter studies. The high exposure of patients to multiple antibiotic classes highlights the importance of strict antibiotic stewardship policies in the current era of global CPE dissemination. Full article