Antibiotics-Basel最新文献

Background/Objectives: Healthcare-associated infections (HAIs) remain a major source of morbidity, mortality, and healthcare burden, and were profoundly affected by the COVID-19 pandemic through changes in case mix, care organization, and antimicrobial use. This study aimed to compare the epidemiology, etiology, ward distribution, risk factors, and outcomes of HAIs during the pandemic and post-pandemic periods in southeastern Romania, with particular emphasis on Clostridioides difficile infection (CDI), multidrug-resistant (MDR) pathogens, and in-hospital mortality. Methods: This retrospective observational study included 3929 patients with confirmed HAIs reported by 10 hospitals in one Romanian county between March 2020 and December 2024, divided into a pandemic period (March 2020-March 2022) and a post-pandemic period (April 2022-December 2024). Sociodemographic, clinical, ward-related, therapeutic, and microbiological variables, together with discharge status and cause of death, were analyzed using Fisher's exact test, Z-tests with Bonferroni correction, the Mann-Whitney U test, and multivariable models, applying national and ECDC-aligned surveillance definitions for HAIs. Results: Patients were predominantly older adults (median age 67 years), with a slight male and urban predominance. Hospital stays were longer during the pandemic. Immunosuppression, previous surgery, antisecretory therapy, and chemotherapy were more frequent post-pandemic. HAIs were mainly reported from medical wards, with a relative shift towards intensive care units during the pandemic; pediatric wards carried a smaller burden. CDI was the leading HAI (about half of all cases) with higher post-pandemic prevalence, whereas SARS-CoV-2 infections predominated in medical and surgical wards; Acinetobacter baumannii and Klebsiella pneumoniae clustered in intensive care units during the pandemic, and were more often associated with mortality. Overall, 59.7% of patients improved and 17.5% died, with higher mortality during the pandemic, while post-pandemic deaths were more frequently unrelated to HAIs. Conclusions: This study demonstrates a substantial and ongoing burden of healthcare-associated infections in southeastern Romania, with elderly patients with prolonged hospital stays and complex medical conditions being most affected and experiencing considerable mortality, particularly in medical and intensive care units. After the pandemic, Clostridioides difficile infections became more prevalent in the context of repeated antibiotic use and immunosuppression. Mortality among patients with HAIs was higher during the pandemic, whereas in the post-pandemic period deaths were more often unrelated to HAIs, underscoring the need to strengthen antimicrobial stewardship programs and infection prevention strategies.

The global rise in antimicrobial resistance among the ESKAPE pathogens represents a major challenge to public health. Here, we report the broad-spectrum antibacterial activity of the synthetic antimicrobial and pore-forming peptide C14R against all six ESKAPE species. Using a radial diffusion assay and resazurin-based viability testing, C14R exhibited a potent bactericidal effect with minimum inhibitory concentrations (MICs), defined as the lowest concentration of an antimicrobial agent that completely inhibits visible growth of planktonic microorganisms, ranging from 3.4 µg/mL (Enterococcus faecium, vancomycin-resistant) to 45.2 µg/mL (Klebsiella quasipneumoniae, ESBL). C14R also inhibited biofilm formation by Gram-positive pathogens, with minimum biofilm inhibitory concentrations (MBICs), referring to the minimal concentration required to prevent the development of biofilms, of 15.0 µg/mL (Staphylococcus aureus, MRSA) and 22.0 µg/mL (E. faecium, VRE), whereas Gram-negative biofilms showed higher tolerance. Together, these findings demonstrate that C14R retains high activity against multidrug-resistant ESKAPE strains, highlighting its potential as a lead compound for the development of next-generation antimicrobial drugs to expand the portfolio of available antibiotics and brace health systems against emerging severe infections.

Background/objectives: Pyometra is a life-threatening uterine infection of intact bitches and queens. Despite growing reports of multidrug-resistant (MDR) Escherichia coli in canine reproductive and urinary infections, no whole-genome data were previously available for pyometra isolates from Italy. This study aimed to characterise, by whole-genome sequencing and comparative genomics, the population structure, resistome and virulome of E. coli causing pyometra in companion animals from northern Italy in the context of European datasets.

Methods: Four E. coli isolates (two canine, two feline) from pyometra cases underwent nanopore long-read sequencing. Genomes were compared with Brazilian and Finnish pyometra isolates using core- and accessory-genome analyses, pan-genome partitioning, phylogeny, and gene-based profiling of antimicrobial resistance and virulence determinants.

Results: All Italian isolates belonged to phylogroup B2 and to recognised ExPEC sequence types (ST706/O51:H1, ST141/O2:H6, ST372/O75:H31, ST646/O22:H5). Phenotypically, they were uniformly resistant to several penicillins and early/third-generation cephalosporins but remained susceptible to fluoroquinolones, aminoglycosides and trimethoprim-sulphonamide. The combined 57-genome pan-genome was open yet strongly core-dominated; Italian strains shared an efflux- and regulator-centred intrinsic resistome and a rich ExPEC virulence repertoire (P, S, F1C and type 1 fimbriae, multiple siderophores, colibactin, Vat, haemolysin, CNF1) with Brazilian and Finnish isolates.

Conclusions: Pyometra-associated E. coli from northern Italian pets belong to globally disseminated high-risk B2 lineages that combine extensive virulence with a largely intrinsic resistome, and currently retain susceptibility to several key drug classes, underscoring an important but vulnerable therapeutic window.

Background: Carbapenem-resistant Gram-negative bacilli (CR-GNB) represent a critical threat to patients in intensive care units (ICUs), where limited therapeutic options contribute to elevated mortality. In Latin America and the Caribbean (LAC), the epidemiological burden of CR-GNB remains insufficiently characterized due to fragmented surveillance systems. This systematic review aimed to synthesize pooled prevalence estimates of CR-GNB among Gram-negative isolates recovered from ICUs across LAC countries. Methods: This systematic review was prospectively registered with PROSPERO (CRD420251177826), followed PRISMA 2020 guidelines and the JBI Manual for prevalence reviews. We searched PubMed, Scopus, LILACS, and SciELO from January 2015 to October 2025 without language restrictions. Observational studies reporting phenotypic carbapenem resistance data from ICUs in LAC countries were eligible. Two reviewers independently screened studies and extracted data. A two-level multilevel generalized linear mixed model (GLMM) with logit transformation was employed using a random-effects approach. Risk of bias was assessed using the JBI critical appraisal checklist. Results: Of 25 eligible studies spanning eight countries, 12 contributed 49 observations to quantitative synthesis. Overall pooled prevalence of CR-GNB was 28.88% (95% CI: 17.32-44.05%), with considerable heterogeneity (I² = 95.24%). Species-specific prevalence was highest for Acinetobacter baumannii (72.58%), followed by Klebsiella pneumoniae (37.48%) and Pseudomonas aeruginosa (29.93%). Regional stratification revealed higher prevalence in South America (31.81%) compared to North America (22.65%) and the Caribbean (11.63%). Conclusions: Nearly one-third of Gram-negative isolates from LAC ICUs exhibit carbapenem resistance, with A. baumannii predominating. Substantial inter-study heterogeneity underscores the need for standardized regional surveillance networks and coordinated antimicrobial stewardship initiatives.

Osteomyelitis (OM), an inflammatory condition of the bone tissue, is a complex orthopedic condition marked by chronic inflammation, diagnostic uncertainty, and recurrent infections. Despite standard treatments-including surgical debridement, antimicrobial therapy, and bone reconstruction-many patients continue to experience recurrence and treatment failure. Growing molecular evidence indicates that host genetic factors play a crucial role in shaping immune responses and influencing disease progression in OM. This narrative review synthesizes current knowledge from candidate gene single-nucleotide polymorphism (SNP) association studies to illustrate how specific genetic variations contribute to OM pathogenesis, diagnostic refinement, and treatment outcomes. We examined key immunogenetic variants within genes involved in inflammatory signaling, pathogen recognition, and neutrophil regulation. Our synthesis identifies a landscape of pro-inflammatory SNPs, such as IL-1β rs16944 and NLRP3 rs10754558, that are associated with increased susceptibility to chronic or post-traumatic OM, as well as SNPs that are associated with protective effects that may favor infection resolution, such as within the NOS2 and VDR genes. These SNP-driven differences in inflammasome activity, cytokine pathways, and oxidative stress responses highlight emerging opportunities for individualized therapeutic strategies. This review consolidates these variants, providing a genetic framework to analyze host susceptibility and differentiating high risk from protective genetic profiles. Integrating genomic insights into OM management represents a promising shift toward personalized medicine, enhancing diagnostic precision, informing targeted interventions, and improving prognostic assessment. Continued large-scale validation of candidate SNPs and translational genomic models will be essential to support their future clinical application.

Background: Natural antimicrobial peptides (AMPs) present a promising solution to address the global threat of drug-resistant infections; however, their clinical translation is challenged by limitations in stability, cytotoxicity, and production costs.

Methods: In the present study, a linear Battacin-derived peptide (DDLFD) was modified at the N-terminus with lipid chains, cinnamic acid, or lipoic acid. The lipoic acid-modified variant was further crosslinked by UV irradiation to form stable nanoparticles. The antibacterial performance against planktonic and biofilm bacteria was systematically evaluated in vitro.

Results: The results demonstrated that lauric acid-modified pentapeptide (C₁₂-5) and crosslinked lipoic acid-modified pentapeptide (cLA-5) exhibited potent and rapid-acting effects against various pathogens, including methicillin-resistant Staphylococcus aureus (MRSA). Moreover, they showed enhanced efficacy in eradicating bacterial biofilms. Biosafety assessments based on hemolysis and cytotoxicity assays indicated favorable biocompatibility profiles of cLA-5. Mechanistic investigations confirmed that the modified pentapeptides retained a membrane-targeting mode of action characteristic of natural AMPs, involving membrane depolarization and increased permeability. This physical mechanism effectively prevented the development of resistance in sequential passaging assays and showed strong synergistic effects with ciprofloxacin against ciprofloxacin-resistant strains, effectively restoring their antibiotic susceptibility.

Conclusions: Together, these findings underscore the strategic potential of rational structural modification, especially the crosslinked nanostructure, in advancing engineered AMPs toward clinical application.

Antimicrobial resistance (AMR) continues to stand as a critical global healthcare challenge [...].

Background: Listeria monocytogenes infection during pregnancy remains an underrecognized cause of severe neonatal disease, frequently leading to central nervous system (CNS) involvement with high mortality and long-term neurological sequelae. Case presentation: We report a case series of four neonates with confirmed neonatal listeriosis and neurological complications, managed in a tertiary neonatal intensive care unit (NICU). Clinical features, microbiological findings, neuroimaging, treatments, and outcomes were analyzed. Our cases presented with early-onset disease and severe clinical courses, including sepsis, meningitis, ventriculitis, hydrocephalus, and seizures. Neuroimaging revealed extensive CNS injury, ranging from intraventricular hemorrhage to multiloculated hydrocephalus. Outcomes varied from near-normal neurodevelopment to profound neurological impairment, despite appropriate antimicrobial therapy. A narrative review of previous cases of neonatal listeriosis was also performed to contextualize our findings. Conclusions: Neonatal listeriosis remains associated with severe neurological morbidity. Early recognition, advanced neuroimaging, multidisciplinary management, and preventive maternal strategies are essential to improve outcomes.

Background: Bacteriophages and phage-derived lytic enzymes are increasingly considered to be targeted antimicrobial tools in aquaculture; however, their compatibility with non-target microbial communities under hatchery-relevant conditions remains insufficiently characterized. Objectives This study evaluates the impact of a lytic phage (CH20) and a phage-derived lysin (LysVp1), applied under previously validated conditions for rapid Vibrio control, on the microbiota associated with seawater, rotifers, and zebrafish larvae challenged with Vibrio alginolyticus GV09.

Methods: Treatments were independently applied to each biological matrix using short exposure times representative of hatchery practices, intentionally capturing the critical window during which microbial transfer from live feed to larvae occurs. Microbial communities were analyzed using 16S rRNA gene sequencing, with DNA- and RNA-derived datasets evaluated separately.

Results: Alpha diversity indices were compared using appropriate statistical tests, while beta diversity was assessed using Aitchison distance, PERMANOVA, and dispersion analyses, and differential abundance was evaluated using ANCOM-BC2. Alpha diversity metrics showed no significant differences among treatments across all matrices, indicating the preservation of microbial richness and diversity. Beta diversity patterns differed according to the nucleic acid source, with RNA-based analyses revealing treatment-associated shifts in rotifer and water microbiota that were not consistently detected at the DNA level. In zebrafish larvae, neither phage nor lysin treatment significantly altered overall community structure, although dispersion effects reflected limitations related to sample size.

Conclusions: Overall, these results indicate that phage CH20 and lysin LysVp1 exert minimal impact on alpha diversity and limited, context-dependent effects on microbial community structure, supporting their microbiota-safe potential for aquaculture applications.

The hands of dental students and practitioners are a key epidemiological factor in the transmission of infections associated with dental care. Strict adherence to the established hand hygiene protocols, combined with regular training and monitoring the quality of the performed hygienic hand disinfection, is crucial for ensuring safe dental practice. Objectives: The aim of the study is to assess the quality of hand antisepsis performed with alcohol-containing preparation among dental students and practicing dentists. Methods: A prospective epidemiological and microbiological study was conducted on 225 people-149 students from the 4th, 5th and 6th year of training at the Faculty of Dental Medicine, Plovdiv, and 76 dentists. The skin antiseptic was applied according to the "six steps" method with alcohol-based antiseptics. The samples were taken with a dry sterile swab. Results: The comparison between students and practicing dental medical doctors shows that the latter have a higher relative share of samples with microbiological growth 12 (15.8%), including coagulase-negative staphylococci (CoNS) above 10⁵ CoNS, compared to students 6 (4.0%), (p = 0.004). Gram-negative microbiological isolates indicate a statistically significant gender dependence (p = 0.016)-15 in men (15.8%), compared to 7 in women (5.4%). Growth of fungi (yeasts and mols) is statistically significant depending on gender (p = 0.015) and is observed only in men. Conclusions: The presence of significant microbial counts of CoNS is an indicator of insufficiently effective hygienic hand disinfection. The recovery of Gram-negative enteric bacteria is unacceptable and suggests serious shortcomings in the hygienic disinfection of some of the samples studied. Students demonstrated superior hand antisepsis performance compared to practicing dentists.