Future microbiology最新文献

Aim: Bacillus subtilis, an endotoxin-free organism recognized for its safety, has been extensively developed as a platform for recombinant protein production. In this study, we investigated the inducer-free secretion expression of components of the Panton-Valentine Leukocidin (PVL) toxin, LukF-PV and LukS-PV, from Staphylococcus aureus in B. subtilis, and evaluated the immune response to the recombinant proteins in intranasally immunized mice.

Methods and results: This study investigated the secretion of recombinant LukF-PV and LukS-PV expressed in B. subtilis, using an inducer-free system controlled by a strong Pgrac212 promoter. The genes encoding LukF-PV and LukS-PV were integrated into the B. subtilis chromosome at the lacA locus. LukF-PV was produced at high levels, whereas LukS-PV was expressed at lower levels in an inducer-free manner. The presence of both the recombinant proteins was confirmed by Western blotting and quantified by densitometry. The intranasal administration of concentrated secretions to mice elicited significant antigen-specific IgA and IgG responses, providing both mucosal and systemic immunity.

Conclusion: These findings highlight the potential of the inducer-free expression approach for recombinant protein secretion in B. subtilis, supporting its application in vaccine development.

Purpose: Burn patients are highly susceptible to infections due to disruption of the skin barrier, and prolonged hospital stays. This study aimed to describe the microbial landscape and antimicrobial resistance patterns in burn unit and to identify clinical predictors of mortality.

Methods: We retrospectively analyzed 743 culture-positive specimens from 200 patients hospitalized between 2020 and 2024. clinical characteristics, and microbiological findings, were evaluated. Antimicrobial susceptibility testing was performed using automated systems and interpreted according to (EUCAST) standards. Logistic regression was applied to determine factors associated with in-hospital mortality.

Results: The cohort was predominantly male (70%), with a median age of 42.5 years (IQR 30-60). Flame burns were the leading cause (58%), and ≥20% total body surface area (TBSA) involvement was observed in 63%. Overall mortality was 33.5%, and was independently associated with male sex, age ≥66 years, full-thickness burns, TBSA ≥20%, and hospitalization < 1 month (p < 0.05). Pseudomonas aeruginosa and Acinetobacter baumannii were the most frequent gram-negative pathogens. Methicillin-resistant Staphylococcus aureus constituted a large proportion of gram-positive isolates.

Conclusion: This five-year assessment underscores the substantial burden of multidrug-resistant organisms in burn units. The findings highlight the importance of unit-specific antibiograms, robust infection prevention measures, and strengthened antimicrobial stewardship to optimize outcomes in this high-risk population.

Biofilm eradication remains a significant challenge in clinical practice and contributes substantially to healthcare costs. Medical devices serve as a common substrate for biofilm formation and are implicated in a considerable proportion of invasive candidiasis cases. Rezafungin, a next-generation echinocandin, exhibits broad-spectrum fungicidal activity against Candida spp. and in vitro studies have confirmed its efficacy against Candida biofilms. A literature review up to July 2025 was conducted, including PubMed, Embase, Web of Science, and gray literature, focusing on the real-world use of rezafungin for device-related and other biofilm-associated Candida infections. Real-world data may suggest its clinical effectiveness in managing complex fungal infections frequently associated with biofilms, such as implant-associated infections, endocarditis, or osteoarticular infections, particularly in co-morbid patients. Among the 18 reviewed cases, mostly coming from Europe and the United States, a successful outcome was reported in 83.3% of patients after a median treatment duration of over 3 months, with no serious drug-related adverse events reported. Although these findings should be interpreted cautiously, given the limited sample size and heterogeneity of cases, they support rezafungin as a potential therapeutic option for biofilm-associated fungal infections.

Aim: Microbes are increasingly being explored as tools to control leishmaniasis and sandfly populations. This study investigated the interactions between sandflies, Leishmania, and their microbiota.

Methods: The in vitro and in vivo survival and development of Leishmania major in the presence of seven bacterial species were assessed. In vitro experiments included Leishmania co-cultures with bacteria applied at different concentrations (10²-10⁸ CFU/ml), monitoring parasite survival/development at early (30-120 min) and late (12-240 h) time points. In vivo experiments in Phlebotomus papatasi examined Leishmania infection rate and intensity on days 2, 6, and 8 post co-infection with the same bacterial species (10⁸ CFU/ml).

Results: All bacteria demonstrated negative effects on Leishmania survival and development. Under in vitro conditions, the speed of Leishmania ablation (48-216 h) depended on the bacterial species and concentration, impacting Leishmania motility and viability, and halting the development of metacyclic forms. In vivo studies demonstrated that bacterial overgrowth negatively impacted the intensity of Leishmania infection and percentage of stomodeal valve colonization (27.58-82.14%).

Conclusions: The observed effect of bacteria on Leishmania under in vitro and in vivo conditions points out toward the potentially greater role of microbes in Leishmania survival in vectors, highlighting the need for deeper investigations of sandfly-Leishmania-microbiota interactions.

Background: Nocardia spp. are Gram-positive, acid-fast, aerobic bacteria that typically affect immunocompromised individuals, primarily involving the respiratory tract and central nervous system, though skin dissemination may occur. Cutaneous nocardiosis is rare and often misdiagnosed.

Case presentation: We report a case of a 57-year-old Brazilian man, immunocompetent, who presented with a pustular lesion, cellulitis, and ascending lymphangitis on his right leg. His work in plant cultivation and public sanitation suggested environmental exposure. Sporotrichosis was initially suspected, and empirical treatment with itraconazole and cefuroxime was initiated. Bacterial cultures were negative, but fungal cultures revealed an acid-fast organism identified by MALDI-TOF as Nocardia brasiliensis. Treatment was switched to sulfamethoxazole. The patient showed complete lesion resolution within 30 days, without scarring. Therapy was maintained for two additional months, leading to full recovery.

Conclusions: Cutaneous nocardiosis may mimic other subcutaneous infections like sporotrichosis, delaying accurate diagnosis and appropriate treatment. Clinical suspicion, coupled with laboratory confirmation, is essential for correct management. The use of MALDI-TOF facilitated precise identification of N. brasiliensis, underscoring the importance of specialized microbiological tools. Integrating clinical, epidemiological, and laboratory data is crucial for the diagnosis and successful treatment of rare infections such as lymphocutaneous nocardiosis.

Objective: To evaluate the first application of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) as a typing tool for Burkholderia pseudomallei.

Methods: A total of 138 B. pseudomallei strains isolated from Hainan, China, were identified and subtyped using MALDI-TOF MS and compared with their multilocus sequence typing (MLST) profiles.

Results: The strains were identified by MALDI-TOF MS using the research use only (RUO) database, and were all correctly identified to the species level. Cluster analysis of all peaks obtained from MALDI-TOF MS did not yield clearly delineated clusters. However, based on the cophenetic correlation analysis of the differential mass spectrometry peaks among the 18 MLST types, all the strains could be divided into four groups. The sequence types exhibited overlapping distributions among various MALDI groups. The comparative analysis of the two methods revealed that the identification capability of MALDI-TOF MS was lower than that of MLST.

Conclusion: Our study represents the first application of MALDI-TOF MS for subtyping B. pseudomallei strains and confirmed the potential application of MALDI-TOF MS for subtyping B. pseudomallei. MALDI-TOF MS is a more convenient and cost-effective instrument for the identification and typing of bacteria, as well as a promising supplementary methods for MLST.

Background: The incidence of carbapenem-resistant Klebsiella pneumoniae (CRKP) infection following liver transplantation (LT) has been increasing. The primary objective of this study was to investigate the utility of rectal swab screening for CRKP in this patient population.

Methods: We retrospectively collected rectal swab screening data from 472 liver transplant recipients between June 2018 and December 2023. Subsequently, we analyzed the risk factors associated with CRKP bloodstream infections (BSIs) and assessed the incidence of CRKP BSIs following an intervention involving a combination therapy of tigecycline and polymyxin.

Results: Among the 472 liver transplant recipients, 38 (8.1%) tested positive for CRKP in rectal swab screening. Univariate analysis identified severe hepatitis (P = 0.008), delayed recovery of transplanted liver function (P = 0.006), and the use of anti-human thymocyte immunoglobulin (P = 0.020) as significant risk factors for CRKP BSIs. The incidence of bloodstream infection was significantly lower in recipients who received the intervention treatment compared to those who did not (P = 0.021).

Conclusions: Rectal swab screening in liver transplant recipients provides early warning for the development of CRKP BSIs. Early intervention in high-risk patients with positive rectal swab results may effectively reduce the incidence of CRKP BSIs.

Silver nanoparticles (AgNPs) have gained prominence in the scientific literature as potential antifungal therapeutic agents, especially those obtained through biological synthesis, due to their superior physicochemical properties. This review examines formulations and patents incorporating AgNPs with antifungal activity, focusing on their applicability in the treatment of mycoses, particularly in vivo. Comparative data on the mechanism of action of AgNPs in planktonic cells and biofilms are presented, as well as transcriptional analyses in fungi exposed to these nanoparticles. The results demonstrate that formulations containing AgNPs have been applied in various contexts, such as wound dressings, in combination with pharmaceuticals, dental products, and cosmetics, reflecting the growing search for therapeutic alternatives, especially for superficial infections. In experimental models, AgNPs demonstrate applicability in the treatment of dermatomycoses and opportunistic mycoses, promoting healing, low toxicity, and reducing fungal load. They can be used alone or in combination with conventional antifungals. Although still poorly understood, the impact of AgNPs on fungal gene expression suggests modulation of virulence, with potential relevant therapeutic implications. The antifungal activity of AgNPs is effective, although the required concentration varies depending on the target - planktonic cells or biofilms. These data highlight the importance of expanding studies to other fungal pathogens.

Tuberculosis, a leading killer among infectious diseases worldwide, is caused by Mycobacterium tuberculosis (Mtb). Mtb has strong ability to manipulate the intracellular environment of macrophages for successful surviving. Mitochondrion is a key organelle involved in diverse physiological processes, including Ca²⁺ fluxes, ATP synthesis, bioenergetic metabolism, and cell death, which are pivotal to cellular and organismal homeostasis. Mitochondrion is also targeted by Mtb to control various physiological responses of the host. Mtb has evolved a series of strategies to manipulate mitochondrial functions in favor of their survival, replication, and dissemination. In mitochondrion, Mtb regulates cell energy metabolism and cell death pathway. Herein, we reviewed the latest advances in the interactions between Mtb and mitochondria and discussed multiple aspects of the influence of Mtb on mitochondrial metabolism to shed light on the Mtb-induced pathogenesis.

Following the discovery of the prokaryotic adaptive immune system known as clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated (Cas) proteins, this technology has revolutionized biotechnology as a multifaceted genome-editing tool with a wide range of applications. CRISPR technology has not only provided novel treatment options, especially for genetic diseases, but also transformed molecular diagnostic platforms. The specific, sensitive, and adaptable nature of the CRISPR-Cas systems has led to the development of innovative solutions for the detection of diseases, including viral and bacterial infections. This review provides an overview of the CRISPR-Cas systems and mainly focuses on the application of CRISPR-based assays for the detection of Bordetella pertussis, which is the main causative agent of a highly infectious disease, whooping cough. The review emphasizes the need for novel diagnostic tools for B. pertussis, along with highlighting some future perspectives, since its diagnosis can be challenging due to nonspecific early symptoms and interference from closely related Bordetella species. In this regard, CRISPR-based diagnostic platforms can offer a promising avenue for rapid and accurate detection of B. pertussis, helping the management of whooping cough.