Future microbiology最新文献

Introduction: Candida parapsilosis has emerged among invasive fungal infections, boming an alarming problem for human health. Recent studies have focused on antimicrobial peptides and their derivatives, such as the Aurein family, as a new approach to developing cutting-edge antifungal agents.

Objective: This study aimed to evaluate the antifungal potential of Aurein 1.2 (Au) and two modified analogs, K-aurein (K-au) and D-aurein (D-au), containing an additional lysine or aspartic acid residue, respectively, at the N-terminal of the native peptide.

Materials & methods: To this, antifungal activity, time of action by time-kill curve, ergosterol-binding analysis in vitro and in silico, and antibiofilm assays were performed. Results: We found that K-au demonstrated the lowest cytotoxicity and the greatest antifungal activity compared to other tested peptides. K-au showed MIC values ranging from 62.5 to 125 μg/mL and time of action fungicide between 60 and 180 min. Molecular docking indicated strong interaction with ergosterol, particularly for K-au, supporting a membrane-targeting mechanism. Biofilm assays demonstrated that the peptides inhibited biofilm formation by up to 80% and were effective against mature biofilms, as confirmed by ultrastructural analysis.

Conclusion: These findings highlight Au-derived peptides as promising molecules against C. parapsilosis.

Aims: Dental caries is a globally chronic disease, with Streptococcus mutans (S. mutans) identified as a principal cariogenic pathogen due to its multifaceted virulence attributes. Understanding the molecular regulation of S. mutans cariogenic virulence is critical for advancing targeted prevention and therapeutic strategies. The objective of this study is to map the research trajectory and future trends in molecular regulation of S. mutans cariogenic virulence.

Methods & methods: This study conducted a comprehensive bibliometric and scientometric analysis of 470 publications from 1994 to 2024 using Web of Science Core Collection data. Advanced analytical platforms, including CiteSpace, VOSviewer and R, were employed to visualize the field's development trajectories and identify hotspots.

Results: The results reveal an evolving focus from basic gene-level and metabolic studies to complex regulatory networks involving quorum sensing, two-component systems and environmental adaptation. In recent years, increasing emphasis has been placed on post-transcriptional and post-translational regulatory mechanisms, notably lysine acetylation, malonylation, and glutathionylation, which orchestrate virulence factor expression, stress responses, and biofilm dynamics.

Conclusions: This work provides the first systematic overview of the development, hotspots, and emerging trends in molecular regulation of S. mutans cariogenic virulence research, offering a theoretical foundation for future investigations and novel anti-caries strategies.

Background: The study proposes to evaluate the impregnation of Foley catheters, in different concentrations of CPZ, to control the formation of biofilms in vitro by the uropathogens most commonly associated with indwelling catheters.

Materials & methods: Minimum inhibitory concentrations (MICs) for CPZ and the effect of CPZ (at different concentrations) on biofilm formation were evaluated. Biofilm formation and the effect of CIP and MER on mature biofilms in CPZ-impregnated catheters were evaluated.

Results: The CPZ MIC was 312.5-625 µg/ml. CPZ significantly (p < 0.05) disrupted biofilm formation at all tested concentrations. In addition, the tested CPZ potentiated the action of CIP.

Conclusions: Our results suggest the use of CPZ by impregnation of catheters can prevent the formation of bacterial biofilms, preventing urinary infections through this route.

Introduction: Antimicrobial resistance (AMR) is a growing global concern, necessitating alternative strategies to fight bacterial infections. Bacteria use quorum sensing (QS) to regulate their virulence, biofilm formation, and resistance mechanisms. Quorum quenching (QQ) disrupts QS, reducing pathogenicity and potentially lowering the selective pressure for resistance compared to conventional antibiotics. Understanding QS and QQ mechanisms can aid in developing effective antimicrobial therapies.

Areas covered: This review examines QS and QQ mechanisms, focusing on key signaling molecules like acyl-homoserine lactones (AHLs) and autoinducer-2 (AI-2). Various QQ agents, including enzymes and phytocompounds are discussed for their roles in disrupting bacterial communication. Phytocompounds such as curcumin, resveratrol, and quercetin have shown potential in inhibiting QS-regulated biofilms and virulence factors.

Expert opinion: QS inhibition and QQ present promising antimicrobial strategies. By targeting bacterial communication rather than growth, these approaches help mitigate resistance development. Future research should focus on optimizing QQ therapies, integrating them with antibiotics, and enhancing their clinical applications through advanced drug delivery systems to improve treatment outcomes.

Aim: To explore the oral microbiota in healthy individuals with and without oral human papillomavirus (HPV) infection and identify any features or changes in the oral microbiota associated with intermediate HPV infection.

Materials and methods: PacBio HiFi sequencing of the whole 16S rRNA gene was performed on 128 saliva samples from a previously characterized cohort (64 HPV-positive and 64 HPV-negative). Statistical analysis of alpha- and beta-diversity, as well as taxonomic composition (differential abundance testing), were used to determine differences between-subject groups.

Results: We demonstrated (1) significant differences in the abundance of Streptococcus salivarius in oral HPV-negative males; (2) males with low-risk HPV had an increased abundance of several species and (3) decreased abundance of Streptococcus salivarius and Streptococcus parasanguinis. For women, (4) oral microbiota Shannon diversity was significantly lower in HPV-positive subjects compared to HPV-negative subjects and (5) oral community structure (beta-diversity) was significantly different when stratified by HPV status.

Conclusions: Intermediate oral HPV infection is associated with several perturbations in the abundance of some bacterial taxa in the oral microbiota, which differ between males and females. Further research is required to determine whether these changes contribute to oral carcinogenesis.

Aims: To investigate the resistance profiles of mastitis-associated methicillin-resistant Staphylococcus aureus (MRSA) and to evaluate the synergistic antibacterial effects of antibiotic combinations.

Methods: Twenty clinical isolates obtained from patients with lactational mastitis underwent antimicrobial susceptibility testing. Six multidrug-resistant (MDR) isolates were selected to assess pairwise combinations of 10 antibiotics by checkerboard assays and to confirm bactericidal synergy via time-kill testing. In vivo efficacy of the combinations was assessed in a Galleria mellonella infection model.

Results: Over 90% of the isolates were MRSA, with high resistance to oxacillin, clindamycin, and gentamicin; several also displayed elevated minimum inhibitory concentrations (MICs) of vancomycin. Vancomycin plus oxacillin (VAN+OXA) or rifampicin (VAN+RIF) showed consistent in vitro synergy. VAN+OXA produced the greatest killing, reducing bacterial counts by > 3 log₁₀ CFU/mL at 24 h. In vivo, both combinations significantly improved larval survival versus monotherapy across multiple strains.

Conclusions: VAN combined with OXA or RIF exhibited robust synergy against mastitis-linked MDR-MRSA in vitro and in vivo. These findings highlight that the combination of VAN with OXA or RIF could be a promising strategy for treating mastitis caused by drug-resistant MRSA.

Aims: Anti-tumor vaccines that target the early proteins E6 and E7 of human papillomavirus (HPV) type 16 represent a potential immunotherapy for cervical cancer, although underlying mechanisms remain unclear. Lactococcus lactis (L.L) is generally regarded as safe (GRAS) which has potential as vehicle. Study investigated the immunoregulatory effect of L.L on dendritic cells (DCs) activation. Besides, antigen delivery and anti-tumor effects of DC-based vaccine prepared with recombinant L.L vaccine (L.L-De) carrying prokaryotic-eukaryotic HPV-16 E6E7 fusion antigen were explored.

Methods: Study performed flow cytometry and MTT to analyze the adjuvant efficacy in promoting DC activation and proliferative capacity of T lymphocytes. The anti-tumor effect of DC vaccine prepared with L.L-De was assessed in C57BL6 tumor model.

Results: Recombinant L.L carrying the expression frame for HPV-16 E6E7 fusion protein in prokaryotic-eukaryotic expression systems exhibited antigen-promoting and cross-presenting adjuvant activity successfully. the developed DC-L.L-De vaccine induced antigen-specific Th-1 and cytotoxic T lymphocyte responses, which inhibited TC-1 tumor growth.

Conclusions: This study demonstrated that recombinant L.L which carries a dual-expression antigen frame, is a promising vector for tumor antigen delivery.

Fluconazole resistance in Candida parapsilosis is an increasing global concern, with resistance rates varying widely and reaching up to 80% in some regions. This trend has led to hospital outbreaks, primarily driven by mutations in the ERG11 gene, especially the Y132F substitution. The clinical relevance of fluconazole resistance remains controversial, as studies have yielded conflicting results regarding its impact on mortality. While some studies described an increased mortality associated with resistant strains, others reported no significant difference. Treatment options are limited: echinocandins and liposomal amphotericin B (L-AmB) are commonly used alternatives, but their use is challenged by intrinsic and emerging echinocandin resistance and L-AmB toxicity and cost. These limitations emphasize the need for robust antifungal stewardship and the development of new therapies. Novel agents such as rezafungin, fosmanogepix, and ibrexafungerp have shown promising activity against fluconazole-resistant C. parapsilosis, though further clinical studies are needed to confirm their efficacy. This narrative review aims to summarize current evidence on the epidemiology, clinical implications, and therapeutic approaches for fluconazole-resistant C. parapsilosis infections.