Antibiotics-Basel最新文献

Background: The aim of this study is to analyze changing trends in isolated organisms and antibiotic resistance of bacterial keratitis (BK) over 26 years.

Methods: A retrospective medical record review included 542 strains isolated from 462 BK patients between 1998 and 2023. We analyzed routinely generated in vitro antibiotic susceptibility testing results recorded in the laboratory information system and did not perform additional susceptibility testing for research purposes. The entire period was divided into two (first half: 1998-2010, 297 isolates from 255 patients; second half: 2011-2023, 245 isolates from 207 patients) and compared.

Results: During the entire period, Staphylococcus spp. (32.3%) and Pseudomonas spp. (18.1%) were common isolates, and a significant increase in Acinetobacter spp. (1.3% vs. 10.6%, p < 0.001) was observed. Among Gram-positive bacteria, methicillin resistance rates remained stable between the two periods (52.6% vs. 46.7%, p = 0.525), and an increase in vancomycin-resistant Enterococci (VRE, 0% vs. 26.1%, p = 0.074) was found. Among Gram-negative bacteria (GNB), ciprofloxacin (7.5% vs. 14.4%, p = 0.108) and imipenem (2.9% vs. 6.5%, p = 0.255) resistance increased slightly, resistance to ceftazidime (8.3% vs. 8.8%, p > 0.999) was maintained, and resistance to aminoglycosides (17.8% vs. 7.2%, p = 0.010) decreased.

Conclusions: Our study suggests that conventional topical fortified antibiotic eye drops (tobramycin, ceftazidime) can still be considered as an empirical treatment option for BK. However, our findings revealed a long-term trend of increasing Acinetobacter spp. and VRE, as well as a slight trend of increasing resistance to ciprofloxacin and imipenem in GNB, which may present future challenges in BK treatment.

The journal retracts the article "An Overview of Antimicrobial Stewardship Optimization: The Use of Antibiotics in Humans and Animals to Prevent Resistance" [...].

Background: Surgical site infections (SSIs) are healthcare-associated infections that can occur following surgical procedures, either at admission or within 30 days post-discharge. This study aimed to assess the incidence and associated risk factors for superficial SSI at a Tertiary Hospital in Ethiopia. Methods: A longitudinal study was conducted among patients undergoing surgery at Jimma University Specialized and Comprehensive Hospital (JUSCH) from 1 June to 30 September 2022. Pus, wound swab, or abscess samples were inoculated on Blood and MacConkey Agar for culture. Bacterial isolates were identified using MALDI-TOF, antimicrobial susceptibility testing was performed using the Kirby-Bauer disc diffusion method, and the results were interpreted according to EUCAST 2022 breakpoints. Incidence rates, Kaplan-Meier analysis, extended Cox regression, and violin plots were utilized to analyze and present the findings. Results: Among 1205 participants, 629 (52.2%) were male, and the median age was 27 years (IQR: 16-40). The incidence of SSI was 9.2 per 1000 person-days. Most SSIs occurred during hospitalization (81.1%), and the remaining primarily developed within the first week post-discharge. The culture positivity rate was 72.7%, yielding 252 isolates comprising 36 bacterial species. The most frequently identified organisms were E. coli (22.2%), Acinetobacter (20.2%), and Klebsiella (14.7%). Over 67% of Gram-negative bacteria were ESBL producers. Age, gender, residence, hospital ward, surgery area, emergency surgery, longer hospitalization, and the number of staff attending the surgery were identified as important risk factors. Conclusions: This study revealed a high incidence of SSI during hospitalization, with significant proportion identified post-discharge. The high rates of multidrug-resistant Gram-negative pathogens underscore the urgent need for comprehensive infection prevention and control measures.

Background: The fungus Acremonium chrysogenum is crucial for producing cephalosporin antibiotics. While CRISPR/Cas9 has been developed for this species, it has not been applied to first-line industrial strains, to the best of our knowledge. For example, engineering industrial A. chrysogenum for overproducing deacetoxycephalosporin C (DAOC, an important precursor for clinically used cephalosporin antibiotics) is currently often a multi-step and inefficient process.

Methods: Here, we applied CRISPR/Cas9 to create a DAOC overproducer in a single step. Our method uses a donor template to simultaneously delete and overexpress genes, offering a simple, efficient, and time-saving solution.

Results: Furthermore, through methodological optimization, the final homozygous multigene-edited strain achieved an industrial-scale DAOC titer of 12.4 ± 0.2 g/L, representing a significant improvement over the initial edited strain (7.2 ± 0.22 g/L).

Conclusions: This demonstrates that CRISPR/Cas9 can effectively edit industrial A. chrysogenum, providing a strategy to enhance the production of other cephalosporin precursors.

Objective: The main aim of the study was to evaluate the role of wild fishes inhabiting in three anthropogenic-impacted Bays in Chile as reservoirs of antimicrobial resistance genes (ARGs). Methods: A total of 245 antimicrobial-resistant isolates were isolated from fish captured in the Coquimbo (142 isolates), Concepción (44 isolates), and Puerto Montt (59 isolates) Bays, and were identified by 16S rRNA gene sequence analysis, Antimicrobial-resistant isolates were tested for susceptibility to 12 antimicrobials by an agar disk diffusion method, and the carriage of genes encoding for resistance to main antimicrobial classes, such as β-lactams, amphenicols, tetracyclines, and sulfonamides by PCR (Polymerase Chain Reaction). Results: A predominance of the Pseudomonas (37.04%), Vibrio (14.40%), and Shewanella (13.99%) genera. Antimicrobial-resistant isolates were tested for susceptibility to 12 antimicrobials by an agar disk diffusion method, showing highest resistance to streptomycin (82.4%), amoxicillin (67.4%), and furazolidone (63.3%), and lowest resistance to ciprofloxacin (3.7%), meropenem (22.5%), and oxytetracycline (29.8%) and exhibiting a high occurrence of the multi-drug resistance phenotype (76.9%). Furthermore, an important number of isolates recovered from sampled fish species carried plasmids (53.5%), floR gene (36.7%), and tet genes (19.2%), whereas the detection of sul genes and class 1-integron was rare. As an overall result, 10.6% of isolates carried at least one bla gene, encoding an extended-spectrum-β-lactamase, with a high predominance of the bla_CTX-M1 gene (23 isolates), whereas 14 out of 245 isolates (5.7%) were positive for the carriage of carbapenemases encoding genes, which both groups exhibited the β-lactam resistance phenotype. Conclusions: The wide distribution of ARG-carrying bacteria in wild fishes from all sampled Bays provides evidence that wild fish are important reservoirs and drivers of spread of ARGs in the marine environment, prompting the need of a continuous surveillance of these genes in wild fishes inhabiting anthropic impacted coastal marine environments in Chile.

Background: Bovine mastitis is a leading cause of economic loss in dairy farming and is increasingly complicated by antimicrobial resistance (AMR), posing challenges to treatment and public health.

Objectives: This study aimed to investigate the prevalence, bacterial etiology, and AMR patterns of mastitis pathogens in dairy herds from the Banat region of Romania.

Materials and methods: A retrospective analysis was conducted on 420 dairy cows from five localities. Mastitis diagnosis involved clinical examination, indirect tests (California Mastitis Test (CMT), R-Mastitest), and bacteriological culture. Antimicrobial susceptibility was assessed using the VITEK^® 2 system.

Results: Out of 420 cows, 120 (28.6%) were diagnosed with mastitis. The predominant pathogens were Staphylococcus aureus (33.3%) and Streptococcus agalactiae (22.5%). Most infections were monomicrobial (70%) and affected a single under quarter (77.5%). Beta-lactam resistance was widespread among both Gram-positive and Gram-negative isolates, particularly against penicillin and ampicillin. Multidrug-resistant (MDR) strains were identified in 33.3% of all isolates, with 100% of Gram-negative isolates exhibiting MDR profiles.

Conclusions: The high prevalence of S. aureus and S. agalactiae, along with widespread beta-lactam resistance and frequent MDR phenotypes, highlights the urgent need for routine AMR surveillance and targeted antimicrobial therapy in bovine mastitis control programs.

Background/Objectives: The overuse and misuse of antibiotics contribute to antimicrobial resistance (AMR) globally. The appropriateness of antibiotic prescribing at the primary healthcare (PHC) level must be urgently addressed to reduce high levels of inappropriate antibiotic prescribing and associated AMR. This study aimed to develop quality indicators, based on the World Health Organization (WHO)'s Access, Watch, Reserve (AWaRe) guidance, to assess the appropriateness and quality regarding antibiotic prescribing in public PHC settings in South Africa. Methods: Potential indicators were identified from indicators developed by City St George's, University of London (SGUL); a review of AWaRe-based indicators; and the results from point prevalence surveys at PHC clinics in South Africa. The indicators were developed using the RAND/UCLA Appropriateness Method. In Round 1, 12 experts individually rated 78 indicators for clarity and appropriateness. In Round 2, 10 experts rated 89 indicators for appropriateness and feasibility during an interactive online meeting. Results: The final set had 61/89 indicators (68.5%) that were rated both appropriate and feasible with agreement. Dental infections (9/9; 100%) alongside skin and soft tissue infections (11/13; 84.6%) had the highest percentage of indicators that were rated appropriate and feasible with agreement. Lower urinary tract infections (6/11; 54.5%) and general (4/8; 50%) categories had the lowest percentage of indicators rated appropriate and feasible with agreement. Conclusions: The process proved valuable in developing potential indicators for use in future antimicrobial stewardship programmes to improve antibiotic prescribing in public sector PHC facilities in South Africa and beyond.

Background/Objectives: The global rise in multidrug-resistant Staphylococcus aureus (MDR-SA) threatens the efficacy of existing antibiotics and necessitates alternative antibacterial strategies. Plant-derived isoflavones represent a promising but underexplored source of novel antimicrobials. Biochanin A, isolated from Cajanus cajan seeds, exhibits antibacterial activity and may act via noncanonical mechanisms. This study elucidates the mechanism of action and safety profile of Biochanin A against MDR-SA using integrated experimental and computational approaches. Methods: Antibacterial activity was assessed by minimum inhibitory concentration (MIC) testing. Membrane integrity and morphological alterations were evaluated using flow cytometry and scanning electron microscopy (SEM), respectively. Target gene modulation was analyzed by qRT-PCR, while molecular interactions were examined through in silico docking. Cytotoxicity was evaluated in normal mammalian kidney, liver, and cardiac cells. Results: Biochanin A inhibited MDR-SA with an MIC80 of 64 µg/mL. Flow cytometry showed membrane disruption in 74.46 ± 13.19% of treated cells, and SEM revealed a 20% reduction in cell size (561.95 ± 21.99 nm). Biochanin A markedly downregulated femA (94%) and femB (67%), with minimal effect on femX (10%). Docking analyses supported preferential binding to FemA (-7.7 kcal/mol) and FemB (-7.5 kcal/mol) proteins. No cytotoxic effects were observed in normal mammalian cells. Conclusions: Biochanin A is a promising plant-derived antibacterial candidate against MDR-SA, targeting key cell wall biosynthesis genes while maintaining mammalian safety. These findings position Biochanin A as a viable lead for further biochemical, structural, and in vivo pharmacological validation, highlighting the translational potential of plant-derived isoflavones in combating antibiotic resistance.

Background/Objectives:Candida infections constitute a significant category of healthcare-associated infections. In studies aiming to develop new antifungal agents against Candida species, the importance of their virulence factors has been emphasized. Methods: This study included 100 Candida isolates obtained from patients hospitalized in intensive care units. Standard microbiological and molecular methods were employed for species identification. Virulence factors were determined through protease, phospholipase, hemolysis, and biofilm activity assays per-formed on the Candida strains. The EUCAST liquid microdilution method was used to assess antifungal susceptibility. Results: Based on sequencing results, 39 isolates were identified as Candida albicans and 61 as non-albicans Candida species. The accuracy of species identification was found to be 71% for Chromagar Candida and 87% for the MALDI-TOF MS system, compared to sequencing. Protease activity was positive in 52% of the isolates, phospholipase in 42%, hemolytic activity in 77%, and biofilm formation in 48%. Kruskal-Wallis analysis revealed no statistically significant interspecies differences in MIC distributions for amphotericin B, fluconazole, itraconazole, or nystatin (p > 0.05), although species-specific trends were observed, with higher fluconazole MICs in C. albicans and lower MIC values in C. tropicalis.Conclusions: Determining the distribution of Candida species, as well as their virulence factors and antifungal MIC profiles, is of great importance for developing appropriate treatment strategies and reducing related morbidity and mortality.

Objective: This study aimed to describe the main microorganisms causing catheter-related bloodstream infections (CRBSIs) and to evaluate the effectiveness of taurolidine catheter lock therapy in children with intestinal failure (IF) receiving parenteral nutrition (PN).

Study design: This retrospective study included 31 pediatric patients with IF admitted between 2017 and 2022 who received PN via central venous catheters (CVCs). Demographic, clinical, and laboratory data were collected, along with information on PN use, catheter characteristics, and infection episodes, including clinical signs, microbiological cultures, and antimicrobial therapy. Serum C-reactive protein and albumin levels, as well as the use of taurolidine lock therapy, were analyzed.

Results: The median age was 54.4 days among patients who developed CRBSI and 154.1 days among those without CRBSI. The median duration of PN was 119 days in patients with CRBSI and 89 days in those without. Nineteen patients experienced CRBSI, accounting for 55 infection episodes confirmed by blood cultures obtained from CVCs. The most frequently isolated microorganisms were Staphylococcus epidermidis, Enterococcus faecalis, and Klebsiella pneumoniae. Taurolidine lock therapy was significantly associated with lower infection rates per 1000 catheter days, with most infected catheters and infection episodes occurring in the absence of taurolidine use.

Conclusions: These findings contribute to the characterization of the microbiological profile of CRBSIs in pediatric patients with IF and support the use of advanced preventive strategies, such as taurolidine lock therapy, to reduce infection rates in children receiving long-term PN.