Antibiotics-Basel最新文献

Background:Clostridioides difficile infection (CDI) remains a challenging condition, particularly in severe or recurrent cases. This study aimed to identify factors associated with recurrent CDI (rCDI), severe disease (defined by ZAR score or ESCMID criteria), death during CDI, and bloodstream infections (BSI) or candidemia within 8 weeks of CDI onset. Methods: We conducted a prospective study at an Italian university hospital that included all adult CDI cases diagnosed between November 2022 and December 2024. Statistical analyses were performed with IBM SPSS Statistics. A p-value < 0.05 was considered statistically significant in univariate analyses. For the multivariable analysis, we selected the variables that were statistically significant in the univariate analysis and considered the most clinically relevant. Results: A total of 161 CDI cases were identified. Recurrence occurred in 13%, higher than the 4% reported in a previous retrospective cohort at the same center (2013-2022). In univariate analysis, independent predictors of recurrent CDI (rCDI) were therapeutic regimens including oral vancomycin (p = 0.008; OR 6.17; 95% CI 1.36-27.97), peripheral vascular disease (PVD) (p < 0.001; OR 5.92; 95% CI 2.07-16.94), and dysphagia (p = 0.034; OR 4.61; 95% CI 1.25-17.07), whereas fidaxomicin use was associated with a protective effect (p = 0.016; OR 0.17; 95% CI 0.04-0.78). In multivariable analysis, oral vancomycin use (p = 0.008; OR 15.03) and peripheral vascular disease (p = 0.002; OR 7.27) remained independently associated with rCDI. Overall, 15 of 161 patients (9.3%) died during the CDI episode (either presenting CDI or rCDI), with all deaths directly attributable to CDI. Mortality during CDI was associated with age > 77 years (median value of the study population), transfer from a nursing home or long-term care facility within the previous 3 months, lymphoma, hematological malignancy, peripheral vascular disease, connective tissue disease, immobilization syndrome, dysphagia, elevated lactate levels (>1 mmol/L), septic shock, severe or severe-complicated CDI according to ESCMID criteria, severe-complicated CDI according to ESCMID criteria, leukocytosis (WBC > 15,000/mm³) during CDI, ZAR score ≥ 2, concomitant BSI, and concomitant pneumonia. During follow-up, 11 of 127 (8.7%) patients developed a BSI. BSI was associated with corticosteroid use and osteomyelitis. Only four patients developed candidemia due to Candida albicans during follow-up. Conclusions: Our study confirms that Clostridioides difficile infection remains a major clinical challenge, particularly due to its high recurrence rate and the burden of severe forms. The evidence strongly supports the preferential use of fidaxomicin, which should now be regarded as the standard of reference in clinical practice.

Background: Canine skin and ear infections are common in small-animal practice and increasingly complicated by multidrug resistance (MDR), yet data from Serbia are limited. This study aimed to describe the bacterial etiology and antimicrobial resistance patterns in canine otitis externa and pyoderma. Methods: We retrospectively reviewed laboratory records from the Clinical Bacteriology and Mycology Laboratory, Faculty of Veterinary Medicine, University of Belgrade (January 2017-August 2024). A total of 422 non-invasive swabs from clinically ill dogs were included (ears: n = 210; skin: n = 212). Bacterial identification used conventional methods and commercial systems, and disk-diffusion susceptibility testing followed CLSI/EUCAST guidance. Methicillin resistance in staphylococci was assessed by cefoxitin/oxacillin screening; MRSA was confirmed by PCR and PBP2a detection. Resistance trends were compared between 2017-2020 and 2021-2024. Results: The leading pathogens were Staphylococcus pseudintermedius (ears 48.1%; skin 79.7%) and Pseudomonas aeruginosa (ears 29.1%; skin 7.6%). Staphylococci showed high resistance to macrolides, clindamycin, tetracycline, and first-line β-lactams (amoxicillin-clavulanate, cephalexin), with the highest susceptibilities to amikacin, florfenicol, and rifampicin. P. aeruginosa remained most susceptible to amikacin, polymyxin B, and imipenem. Between the two periods, S. pseudintermedius resistance increased to amikacin, fusidic acid, and cephalexin, while resistance to florfenicol decreased. P. aeruginosa resistance to imipenem increased. The prevalence of methicillin-resistant S. pseudintermedius (MRSP) was 27.4% (74/270). MDR S. pseudintermedius and MDR P. aeruginosa were identified in 38.5% and 53.3% of isolates, respectively. One isolate of each species was resistant to all tested drugs. Conclusions: These findings confirm high levels of antimicrobial resistance in major canine skin and ear pathogens and emphasize the need for susceptibility-based therapy, rational antimicrobial use, and ongoing surveillance in small-animal practice.

Background: This study investigated the phenotypic and genotypic antibiotic resistance profiles of 50 Lactic Acid Bacteria (LAB) strains-25 Lactiplantibacillus plantarum and 25 Lacticaseibacillus paracasei-isolated from traditional Sardinian fermented foods of animal origin.

Methods: The sensitivity of the isolates to antibiotics such as β-lactams, tetracyclines, aminoglycosides, macrolides, phenicols, and glycopeptides was initially assessed using disc diffusion and minimum inhibitory concentration (MIC) tests. Subsequently, PCR analyses were performed on both genomic DNA and plasmid DNA to detect blaZ, tet(W), strA, aac(6')-Ie-aph(2″)-Ia, and vanX genes associated with resistance to ampicillin, tetracycline, streptomycin, gentamicin, and vancomycin.

Results: The analysis revealed that L. plantarum strains frequently carried the tet(W) gene on the chromosome and strA on plasmids, while vanX was detected in most strains as a chromosomal determinant. By contrast, L. paracasei strains exhibited a predominantly plasmid-mediated distribution of resistance genes. For example, strA, aac(6')-Ie-aph(2″)-Ia and blaZ were often found on plasmids, whereas vanX remained chromosomally encoded. Phenotypic assays confirmed high intrinsic resistance to vancomycin in both species, with L. plantarum showing a higher overall frequency and diversity of resistant phenotypes compared to L. paracasei.

Conclusions: The co-occurrence of multiple resistance determinants, including plasmid-encoded ones, in most strains suggests that even autochthonous isolates from artisanal products may represent potential reservoirs for transmissible resistance genes.

Background/Objectives: We investigated multimodal strategies to reduce neonatal ventilator-associated pneumonia (VAP) and antimicrobial use across three periods: period 1 (2014-2017), environmental cleaning with sodium hypochlorite, installation of heat and moisture exchangers, elective high frequency oscillatory ventilation (HFOV) as the primary invasive mode, and nasal HFOV after extubation; period 2 (2018-2020), oral care with maternal milk; and period 3 (2021-2024), nasal synchronized intermittent positive pressure ventilation after extubation. Methods: We conducted a quasi-experimental study of all neonates admitted to a neonatal intensive care unit in Thailand. We compared the trends in VAP and antimicrobial use rates using interrupted time-series analysis with segmented regression. Results: During the 11-year study period, 45.6% of neonates were intubated (2470/5414), and the ventilator utilization ratio was 0.19 (17,820 ventilator days/95,151 patient days). The overall VAP incidence was 4.55 per 1000 ventilator days. The yearly VAP incidence density ratio was significantly lower than in 2014. The baseline trend of VAP incidence and colistin use decreased significantly during period 1; nonetheless, the level and slope did not differ significantly between periods 1, 2, and 3. Conclusions: Tailored implementations, namely environmental decontamination, ventilator circuit care, elective HFOV, and nasal HFOV, reduced VAP and colistin use during period 1. Moreover, additive interventions, including oral care in period 2 and nasal synchronized intermittent positive pressure ventilation in period 3, achieved sustained VAP reduction and limited colistin prescriptions in period 1.

Background/Objectives: Burn wound infections caused by Staphylococcus aureus remain a major clinical challenge, leading to delayed healing and high mortality. Natural compounds derived from the Lamiaceae family possess antimicrobial and anti-inflammatory properties that may modulate wound recovery. This study aimed to evaluate the dual modulatory effects of Satureja montana and Origanum vulgare hydrolate-loaded hydrogels on modulation of infection and skin recovery in an experimental rabbit model of S. aureus-infected burns. Methods: Full-thickness (grade IIIa) thermal burns were induced in 25 male New Zealand White rabbits, followed by inoculation with S. aureus (10⁸-10⁹ CFU/mL). Animals were divided into five groups: sham control, burn-infection control, standard-of-care intervention, Satureja montana hydrolate intervention, and Origanum vulgare hydrolate intervention. Treatments were applied twice daily for 14 days. Bacterial load (CFU/g), biochemical markers, histological parameters, and multiplex immunohistochemical indices (Ki-67, CD68, CD163) were analyzed. Results: Both hydrolate-based formulations exhibited pronounced antibacterial effects, significantly reducing S. aureus counts by day 14 compared to untreated burns (p < 0.001). Immunohistochemical analysis revealed enhanced cell proliferation and a rapid shift from pro-inflammatory M1 (CD68+) to reparative M2 (CD163+) macrophages, indicating effective immune resolution. The hydrolate-loaded hydrogels effectively combined antimicrobial activity with tissue-regenerative and immunomodulatory effects. The S. montana formulation demonstrated superior performance, representing a promising adjunctive therapy for infected burn wounds. Conclusions: This study represents the first comparative in vivo evaluation of S. montana and O. vulgare hydrolate-loaded hydrogels in a complex S. aureus-infected burn model.

Burkholderia is a metabolically versatile genus of Gram-negative bacteria that inhabits niches ranging from soil and water to plants and clinical environments. This review provides an integrated examination of Burkholderia species, focusing on their dual roles as both pathogens and beneficial microorganisms. Key pathogenic species, such as members of the Burkholderia cepacia complex and the Burkholderia pseudomallei group, pose significant threats to human, animal, and plant health due to their intrinsic antibiotic resistance and diverse virulence factors. Conversely, several environmental and plant-associated Burkholderia species promote plant growth, enhance nutrient uptake, and serve as biocontrol agents, supporting sustainable agriculture. We synthesize current knowledge across taxonomy, genomics, pathogenicity, beneficial interactions, and secondary metabolite biosynthesis-including the prolific production of antibiotics, toxins, and volatile organic compounds with pharmaceutical and agricultural potential. Advances in high-throughput genomics are revealing substantial genetic diversity, genome plasticity, and mechanisms underlying both pathogenicity and beneficial traits. Clarifying this dual nature and identifying strategies to mitigate risks will guide the safe and effective exploitation of Burkholderia in medicine, agriculture, and biotechnology.

Background/Objectives: The emergence of hypervirulent Pseudomonas aeruginosa strains resistant to β-lactamase inhibitor antibiotics is a critical health problem as they impede the treatment of infections. The objective of this study was to determine the different molecular arrangements of the virulence genotype related to β-lactamase genotype and the resistance phenotype to a combination of β-lactam antibiotics and β-lactamase inhibitors, and the phylogroups in P. aeruginosa strains isolated from patients with healthcare-associated infections and community-acquired infections. Methods: P. aeruginosa, virulence genes, β-lactamase genes and phylogroups were identified using polymerase chain reaction. Resistance to β-lactam antibiotics and β-lactamase inhibitors was determined using the disk diffusion method. The MIC determination of ticarcillin/clavulanic acid and piperacillin/tazobactam was performed using the MIC test strip for antimicrobial susceptibility testing. Results: In total, 124 P. aeruginosa strains from patients with healthcare-associated (67/124) and community-acquired infections (57/124) were analyzed. Most strains from patients with healthcare-associated infections and community-acquired infections harbored genes for proteases (aprA), phospholipases (pIcH and pIcN), elastases (lasA and lasB), rhamnolipids (rhLA), quorum-sensing system (lasI and rhII), and β-lactamase (bla_oxa-4, bla_oxa-1, and bla_GES). In total, 100% (124/124) and 99.1% (123/124) of the strains isolated from patients with healthcare-associated and community-acquired infections were resistant to the β-lactamase inhibitor antibiotics, amoxicillin/clavulanic acid and ampicillin/sulbactam, respectively, while 54% (67/124) of the strains were resistant to piperacillin/tazobactam. Phylogroup 1 (22/124) was detected more frequently among the strains in relation to phylogroup 2 (8/12). Conclusions: We demonstrated different association profiles of virulence genotype related to the β-lactamase genotype, the β-lactamase inhibitor resistome, phylogroups, and clinical origin of the strains. Therefore, medical treatment regimens against infections caused by P. aeruginosa should be improved.

Background/Objectives: The global response to the COVID-19 pandemic included a notable shift in antibiotic prescribing patterns, with use declining and then rising again as restrictions were lifted. In Poland, point-of-care (POC) testing for infections such as influenza A/B, COVID-19, respiratory syncytial virus (RSV), and Group A Streptococcus was widely introduced in primary care in recent years. This study investigates the patterns of oral antibiotic prescription in Poland during the pandemic and post-pandemic periods. Methods: We analyzed Polish National Healthcare Fund data on reimbursed oral antibiotics-Anatomical Therapeutic Chemical (ATC) J01 class-sold between 2019 and 2024. We quantified antibiotic groups by the number of packages sold and individual agents using the defined daily dose per 1000 inhabitants per day (DDD/TID). Results: Total oral antibiotic reimbursements noted a significant fall from 2019 to 2020 (20.9 million vs. 14.5 million packages reimbursed) and subsequently surged from 16.3 million packages in 2021 to 20.9 million in 2024. The most prescribed groups were penicillins (J01C), macrolides (J01F), and other beta-lactams (J01D). Amoxicillin with clavulanic acid was the most commonly used individual antibiotic, with its DDD/TID rising from an average of 2.3 to 2.6 in 2024. Although the use of phenoxymethylpenicillin initially decreased after the introduction of "strep-tests" in 2022 (DID 0.18 in 2023 vs. 0.23 in 2022), it increased again to 0.26 in 2024. Conclusions: Our findings demonstrate a slight continuous increase in oral antibiotic use in Poland, despite the current widespread availability of POC testing. The persistent and growing preference for amoxicillin with clavulanic acid, an agent not typically recommended as first-line treatment for most infections, suggests that antibiotic stewardship efforts need to continue in order to curb inappropriate prescription.

Background: Erysipelothrix rhusiopathiae is an important zoonotic pathogen in poultry, yet little is known about its antimicrobial resistance (AMR) dynamics in avian hosts. With growing concerns about subtherapeutic antimicrobial use in animal agriculture, poultry-origin isolates represent a potential but under-characterized reservoir of resistance genes. Methods: We phenotypically tested 38 E. rhusiopathiae strains isolated from geese, ducks, and turkeys in Hungary (2024) using broth microdilution against 18 antimicrobial agents, following Clinical Laboratory Standards Institute (CLSI) guidelines. Nineteen phenotypically resistant strains were selected for whole-genome sequencing (Illumina platform), followed by de novo hybrid assembly, gene annotation (Prokka, CARD, VFDB), mobile element detection (Mobile Element Finder), and phylogenetic inference (autoMLST). Results: All isolates were susceptible to β-lactams, including penicillin, amoxicillin, and third-generation cephalosporins. Resistance to tetracyclines (up to 10.5%) and florfenicol (5.3%) was most frequently detected. Genomic analysis revealed the presence of tetM (9/19), tetT (2/19), and erm(47) (2/19) genes, all associated with chromosomally integrated mobile elements, ICE Tn6009 and IS ISErh6. Phylogenomic analysis demonstrated tight clustering into four clades, suggesting clonal expansion. Notably, one strain harbored a 64.8 kb genomic island carrying ermC, the first such finding in poultry-derived E. rhusiopathiae. Conclusions: Our data highlights the early emergence of mobile AMR determinants in E. rhusiopathiae from poultry and suggests that horizontal gene transfer may drive resistance even in chromosomally encoded contexts. The genomic stability and phylogenetic homogeneity of avian isolates underscore the need for targeted AMR surveillance in poultry sectors to mitigate potential zoonotic transmission risks.

Background/Objectives: In surgical antibiotic prophylaxis (SAP), most studies continue to report the number of prescriptions aggregated at the hospital level, rarely integrating the World Health Organization (WHO) Access, Watch, and Reserve (AWaRe) classes with standardized volume indicators. This study aimed to evaluate the utilization of antibiotics for SAP in a large Italian teaching hospital using both the number of prescriptions and defined daily doses (DDDs) and mapped the AWaRe models across different surgical specialties to highlight differences relevant to management. Methods: We conducted a prospective hospital-wide surveillance of all consecutive patients undergoing surgical procedures between March and May 2023 at the Azienda Ospedaliero-Universitaria delle Marche. Data included demographics, surgical specialty, and all antibiotic administrations with indication. For SAP, each prescription was classified according to the 2023 WHO AWaRe framework, and consumption was quantified using the WHO ATC/DDD methodology. Results: A total of 914 patients were monitored, with complete antibiotic data for 793 (86.8%). Among 433 SAP prescriptions, the most frequently used agent was cefazolin (82%), followed by amoxicillin/β-lactamase inhibitor (5%) and metronidazole (5%). According to AWaRe, 93% of SAP prescriptions were Access agents and 7% were Watch agents; no Reserve antibiotics were used. When expressed in DDDs (total: 443.5), 87.8% were Access and 12.2% Watch. Cefazolin accounted for over 85% of Access DDDs. Conclusions: By combining AWaRe classes with DDDs and resolving results by surgical specialty, this study extends hospital-level metrics and provides a pragmatic framework for SAP benchmarking. The predominance of Access agents is consistent with management objectives, while differences across specialties identify concrete tools for local quality improvement.