Journal of Applied Microbiology最新文献

{"title":"Synergistic combination of imipenem and 7-fluoroindole inhibits β-lactamases and biofilm in Carbapenem-resistant Acinetobacter baumannii.","authors":"Anandita Chalana, Vipasha Thakur, Varsha Gupta, Prince Sharma, Neena Capalash","doi":"10.1093/jambio/lxaf234","DOIUrl":"10.1093/jambio/lxaf234","url":null,"abstract":"<p><strong>Background: </strong>Acinetobacter baumannii is a nosocomial opportunistic pathogen responsible for hospital and community-acquired infections. It has been categorised as a high-priority ESKAPE pathogen due to escalating resistance, underscoring the urgent need for effective treatment options. This study explores the use of 7-Fluoroindole (7-FI) as an adjuvant to imipenem for combating Carbapenem-Resistant Acinetobacter baumannii (CRAB).</p><p><strong>Methods: </strong>Clinical strains of A. baumannii were subjected to disc diffusion assay for antibiotic resistance profile, and Fractional Inhibitory Concentration (FIC) of 7-FI was determined with imipenem by checkerboard assay. Expression of β-lactamases, efflux pumps, and outer membrane proteins was determined by qRT-PCR. Biofilm inhibition by 7-FI in combination with imipenem was evaluated by Confocal Laser Scanning Microscopy.</p><p><strong>Results: </strong>7-FI reduced the MIC of imipenem by 2 to 8-fold in CRAB strains, and also enhanced susceptibility to meropenem. Mechanistically, 7-FI inhibited the β-lactamase activity by 2.3 to 3.8-fold and downregulated the expression of Class B (blaNDM-1) and D (blaOXA-23 and blaOXA-51) β-lactamases. The efflux pump activity was reduced by 2 to 8.6-fold, and expression of efflux pump genes adeB, adeJ, abeM and emrA was also significantly (p < 0.001) downregulated. 7-FI in combination with imipenem inhibited biofilm formation by 80% even at 1 × FIC (1/4 MIC of imipenem and 1/3 MIC of 7-FI).</p><p><strong>Conclusion: </strong>The combination of 7-FI and imipenem synergistically mitigated carbapenem resistance in A. baumannii by inhibiting the activity of β-lactamases, downregulating the expression of β-lactamases and efflux pumps. The study shows 7-FI as a useful adjuvant to imipenem against CRAB strains.</p>","PeriodicalId":15036,"journal":{"name":"Journal of Applied Microbiology","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2025-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145113052","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Advances and challenges in Helicobacter pylori subunit vaccine development: antigen candidates and immunization strategies.","authors":"Zhili Liu, He Li, Xiaotian Huang, Qiong Liu","doi":"10.1093/jambio/lxaf236","DOIUrl":"10.1093/jambio/lxaf236","url":null,"abstract":"<p><p>Helicobacter pylori, which infects nearly half of the global population, is a major cause of gastrointestinal diseases, including peptic ulcers, gastric cancer, and lymphoma. Current treatment regimens are hampered by antibiotic resistance, high costs, and adverse side effects, highlighting the urgent need for effective vaccines. Several subunit vaccines have demonstrated promising protection or clearance rates in preclinical experiments using animal models, providing a strong rationale for advancing H. pylori vaccines into human clinical trials. However, no vaccine has been commercialized to date, with only the UreB vaccine progressing to Phase III clinical trials. This review discusses recent progress, challenges, and prospects in the development of H. pylori subunit vaccines, with emphasis on antigen selection, adjuvants, immunization strategies, and delivery systems. By evaluating key antigenic candidates and their immunogenic properties, this article aims to provide a comprehensive overview to inform future vaccine development against H. pylori infection.</p>","PeriodicalId":15036,"journal":{"name":"Journal of Applied Microbiology","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2025-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145112969","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exploring the therapeutic role of probiotics and prebiotics in mitigating diseases associated with advanced glycation end products.","authors":"Haiqing Sun, Zhenjiang Liu, Xin Li, Dongxu Wen, Bin Li, Xiaodan Huang","doi":"10.1093/jambio/lxaf233","DOIUrl":"10.1093/jambio/lxaf233","url":null,"abstract":"<p><p>Advanced glycation end products (AGEs) are a class of compounds generated when reducing sugars interact with proteins, lipids, and other molecular structures. Excessive accumulation of AGEs in the body accelerates aging and contributes to various chronic conditions, including diabetes, neurodegenerative diseases, cardiovascular diseases, and inflammatory bowel diseases. Despite growing interest in strategies to prevent glycation damage, effective interventions to combat AGE-related diseases remain limited. This review examines the role of AGEs in disease pathology and evaluates strategies to mitigate their harmful effects. It further summarizes natural products and pharmaceutical agents currently used for anti-glycation purposes, along with their underlying mechanisms. Additionally, we explore the promising therapeutic potential of probiotics and prebiotics in protecting against AGE-related diseases, highlighting research evidence demonstrating their ability to reduce AGE accumulation and inhibit their formation. This review aims to inform the development of more effective glycation inhibitors and addresses the pressing gap in current research regarding targeted AGEs interventions.</p>","PeriodicalId":15036,"journal":{"name":"Journal of Applied Microbiology","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2025-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145091839","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Novel Erythromycin Lipid Nanoformulations for Aquaculture Applications.","authors":"Sarah Chagas Campanharo, Gabriela Alberto Gil, Agnaldo Fernando Baldo da Silva, Inácio Mateus Assane, Daniel de Abreu Reis Ferreira, Fabiana Pilarski, James Jacob Sasanya, Wanderley Pereira de Oliveira, Jonas Augusto Rizzato Paschoal","doi":"10.1093/jambio/lxaf249","DOIUrl":"https://doi.org/10.1093/jambio/lxaf249","url":null,"abstract":"<p><strong>Aims: </strong>This study introduces novel lipid nanoformulations of erythromycin (ERY) designed for aquaculture pathogens and evaluates their in vitro antimicrobial activity compared to pure ERY.</p><p><strong>Methods and results: </strong>Among the tested formulations, the nanoemulsion (F4) demonstrated higher inhibitory effects. The MIC values were 25 µg mL⁻¹ against Aeromonas hydrophila and A. caviae, and for A. veronii, all ERY-loaded nanoformulations displayed high activity (MIC ≤ 3.1 µg mL⁻¹), as determined by the broth microdilution method. Lipid nanoformulations were prepared using a hot emulsification method. The method consisted of high-speed homogenization at 22 000 rpm for 5 minutes using an Ultra-Turrax homogenizer, followed by ultrasonication. The surfactants used included poloxamer and natural surfactants, quillaja (Quillaja saponaria Molina) saponins and whey protein concentrate. The nanoformulations were characterized by particle size (228-500 nm), polydispersity (0.189-0.456), zeta potential (-42 to -27.5 mV), pH (4.54-5.5), conductivity (161-295 µS cm-1), and stability.</p><p><strong>Conclusions: </strong>The nanoemulsion (F4) kept higher ERY content at early time points and showed equal or lower MICs than free ERY against selected Aeromonas spp. The dispersions can be spray-dried to a powder or incorporated into fish feed by extrusion or post-pellet coating-routes rarely reported for ERY in aquaculture. These results support further development of ERY nanoformulations against aquaculture pathogens.</p>","PeriodicalId":15036,"journal":{"name":"Journal of Applied Microbiology","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2025-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145232541","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Same-day multiplex detection of foodborne bacterial pathogens for clinical diagnostics and food safety.","authors":"Pei-Yi Tsui, Fang-Tzy Wu, Yi-Ling Chen, Chu-Yang Chien, Feng-Ping Lin, Chung-Chih Liang, Hsin-Hsien Huang, Chin-Mao Hung, Hsiao-Lun Wei, Shih-Hua Teng, Shan-Ko Tsai, Ching-Yi Wu, Hui-Ling Hsu","doi":"10.1093/jambio/lxaf225","DOIUrl":"10.1093/jambio/lxaf225","url":null,"abstract":"<p><strong>Aims: </strong>This study aims to develop and evaluate a rapid and high-multiplex pathogen detection method for clinical and food specimens to address the ongoing public health threat of foodborne infections and the limitations of conventional culture-based diagnostics.</p><p><strong>Methods and results: </strong>The foodborne bacteria (FBB) assay integrates multiplex PCR, T7 exonuclease hydrolysis, and a suspension bead array to simultaneously detect 16 genes from 13 major foodborne bacteria. Analytical performance was evaluated using reference strains, while diagnostic performance was assessed using clinical and food samples. The FBB assay demonstrated high specificity and sensitivity, with minimum detectable amounts ranging from 5 to 100 copies per reaction for all targets except one. Among 106 clinical specimens from foodborne outbreaks, the assay achieved 99.1-100% overall % agreement with routine methods. In spiked food samples, Bacillus cereus was detected at 1 CFU g-1 in cooked rice, and Listeria monocytogenes at 10² CFU mL-1 in milk; for the latter, sensitivity improved to 10 CFU mL-1 and 1 CFU mL-1 after four and 16 hours of pre-enrichment, respectively.</p><p><strong>Conclusions: </strong>The FBB assay enables culture-independent, multiplex detection of foodborne bacterial pathogens within six hours and demonstrates robust analytical and diagnostic performance.</p>","PeriodicalId":15036,"journal":{"name":"Journal of Applied Microbiology","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2025-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145015493","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Paraclostridium sp. AKS46 vesicles facilitate extracellular electron transport.","authors":"Aparajita Basu, Sangita Mondal, Aindrila Roy, Saibal Tewari, Sanatan Chattopadhyay, Abhrajyoti Ghosh, Alok Kumar Sil","doi":"10.1093/jambio/lxaf239","DOIUrl":"10.1093/jambio/lxaf239","url":null,"abstract":"<p><strong>Aims: </strong>Paraclostridium sp. AKS46 was shown to have high exoelectrogenic activity. The current study investigated whether membrane vesicles (MVs) contribute to electrogenic activity of this organism.</p><p><strong>Methods and results: </strong>To examine the contribution of MVs to electrogenic activity, formation of MVs was first investigated by microscopic analyses of AKS46 cells at different time points of growth. The results showed increasing MV formation with time, especially in electrode-attached cells. To test electrogenic activity, the redox property and the electrochemical activity of the vesicles were examined. To this end, purified AKS46 vesicles demonstrated robust redox activities, and cyclic voltammetry and electrochemical impedance spectroscopy revealed high electrochemical properties of purified vesicles. Furthermore, proteomic analysis of the vesicles identified the presence of redox-active proteins, particularly flavoproteins, which might significantly contribute to electron carrier properties. AKS46 MVs also harbour enzymes involved in CO2 and nitrogen fixation, suggesting their roles in nutrient cycling and maintaining microbial ecology.</p><p><strong>Conclusion: </strong>The exoelectrogenic gram-positive bacteria Paraclostridium sp. AKS46 produces extracellular vesicles packed with electron-rich molecules and thus, these vesicles act as electron transporters. The work highlights a vesicle-mediated mechanism for energy harvesting from waste degradation in microbial fuel cells.</p>","PeriodicalId":15036,"journal":{"name":"Journal of Applied Microbiology","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2025-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145130777","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Low water activity limits bentonite-associated microbial growth.","authors":"Rhiannon Punch, Lucas Beckering Vinckers Stofer, C M James Neurauter, Rachel C Beaver, Katja Engel, Simcha Stroes-Gascoyne, Chang Seok Kim, W Jeffrey Binns, Myrna J Simpson, Greg F Slater, Josh D Neufeld","doi":"10.1093/jambio/lxaf140","DOIUrl":"10.1093/jambio/lxaf140","url":null,"abstract":"<p><strong>Aims: </strong>This research investigated the impact of water activity on microbial abundance estimates from bentonite under conditions relevant to a deep geological repository for used nuclear fuel. Because previous research tested saturation of bentonite within pressurized vessels, the goal of this study was to assess how water activity alone, without pressure, prevents increases in microbial abundance estimates from bentonite samples.</p><p><strong>Methods and results: </strong>Small-scale microcosms of bentonite were hydrated to low, medium, or high water activities, with Type I water, reference groundwater, or bacterial growth medium, then incubated under oxic or anoxic conditions. At six timepoints over a 6-month period, microorganisms were quantified using cultivation-dependent and independent approaches, and 16S rRNA genes were sequenced to monitor relative abundance changes of microbial taxa. Large-scale incubations were then conducted to also enable analyses of phospholipid fatty acids and natural organic matter. The results demonstrate that increasing water activity was associated with higher microbial abundance estimates for oxic condition incubations, with water-activity-dependent actinobacterial growth. In contrast, no significant microbial abundance changes were observed for anoxic microcosm incubations. For all tested conditions, we did not detect any increases in sulfate-reducing bacteria abundance estimates.</p><p><strong>Conclusions: </strong>Although low water activity conditions prevented changes in microbial abundances for bentonite samples incubated under oxic conditions, anoxic conditions alone prevented increases in abundances of culturable microorganisms. These results complement previous pressure-vessel studies that have shown how low water activity and elevated pressure simultaneously reduce the abundance of viable microorganisms that can initially proliferate during the saturation process.</p>","PeriodicalId":15036,"journal":{"name":"Journal of Applied Microbiology","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2025-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144215830","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Linezolid resistance in immunocompromised patients: Co-occurrence of optrA and fexA genes harbored by a novel plasmid in Enterocococus faecalis ST300.","authors":"Anis Raddaoui, Yosra Chebbi, Siwar Frigui, Wafa Achour","doi":"10.1093/jambio/lxaf248","DOIUrl":"https://doi.org/10.1093/jambio/lxaf248","url":null,"abstract":"<p><strong>Aims: </strong>Linezolid resistance in Gram-positive cocci has been reported in clinical settings but it is still a rare phenomenon. This study investigated the molecular epidemiology of linezolid-resistant Enterococcus faecalis strains and the genetic environment of linezolid-resistance genes, in immunocompromised patients.</p><p><strong>Methods and results: </strong>This study investigated two linezolid-resistant Enterococcus faecalis strains (Minimal inhibitory concentration = 16 mg/L). These colonizing strains were isolated from patients at Tunisia's National Bone Marrow Transplant Center. Both strains exhibited a multidrug resistant phenotype. Whole-genome sequencing revealed the co-occurrence of optrA and fexA resistance genes, for the first time, in ST300 and ST861 Enterococcus faecalis. Concerning the ST300 strain, optrA and fexA were located on a novel plasmid pS1987-optrA sharing high similarity with plasmids from clinical isolates in Japan and the Netherlands. Comparative genomics highlighted genetic diversity in the optrA region among geographically linked isolates, suggesting plasmid-mediated spread.</p><p><strong>Conclusion: </strong>This study reported, for the first time, the co-occurrence of optrA and fexA genes in linezolid-resistant Enterococcus faecalis ST300 and ST861, harbored by a novel plasmid in the ST300 strain.</p>","PeriodicalId":15036,"journal":{"name":"Journal of Applied Microbiology","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2025-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145232524","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Gut dysbiosis allows foodborne salmonella colonization in edible crickets: a probiotic strategy for enhanced food safety.","authors":"Shuma Tsuji, Osamu Matsushita, Jumpei Uchiyama, Kenji Yokota, Tetsuya Bando, Hideyo Ohuchi, Kazuyoshi Gotoh","doi":"10.1093/jambio/lxaf217","DOIUrl":"10.1093/jambio/lxaf217","url":null,"abstract":"<p><strong>Aims: </strong>Edible insects, including crickets, represent a promising protein source, yet concerns over foodborne pathogens limit consumer acceptance. This study investigated whether gut microbiota modulates colonization by Salmonella enterica subsp. enterica serovar Enteritidis (SE) in the two-spotted cricket (Gryllus bimaculatus).</p><p><strong>Methods and results: </strong>Under standard conditions, SE was undetectable in crickets despite prolonged exposure; however, antibiotic-induced dysbiosis enabled stable SE colonization. Long-read 16S rRNA sequencing revealed significant microbiota shifts, notably a reduction in Lactococcus garvieae. In vitro assays showed strong inhibitory effects of L. garvieae against SE, and supplementation of dysbiotic crickets with L. garvieae reduced SE colonization by ∼1000-fold.</p><p><strong>Conclusions: </strong>The native cricket gut microbiota, especially L. garvieae, plays a protective role against SE colonization. Enhancing beneficial gut bacteria could mitigate pathogen risks and promote edible insects as a sustainable protein.</p>","PeriodicalId":15036,"journal":{"name":"Journal of Applied Microbiology","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2025-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144955282","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Resveratrol potentiates the antibiofilm and antibacterial activity of polymyxin B against carbapenem-resistant Acinetobacter baumannii.","authors":"Yanhong Li, Bin Wu, Yanli Li, Yanwu Hu, Meijun Wang, Rongxin Liang","doi":"10.1093/jambio/lxaf240","DOIUrl":"10.1093/jambio/lxaf240","url":null,"abstract":"<p><strong>Aims: </strong>Polymyxins are generally recommended to be used in combination with other antibiotics for improving their antibacterial effects. As for treating carbapenem-resistant Acinetobacter baumannii infections, which antibiotic is the best option for polymyxin B-based combination therapy is still under debate. Resveratrol, a natural compound that can be well-tolerated by the human body, may have potential value in the polymyxin B-based combination therapy against carbapenem-resistant A. baumannii infections.</p><p><strong>Methods and results: </strong>With checkerboard assays and time-killing studies, we have found that resveratrol increased the sensitivity of carbapenem-resistant A. baumannii to polymyxin B and enhanced the bactericidal activity of polymyxin B against carbapenem-resistant A. baumannii. With biofilm formation studies, we have confirmed that resveratrol potentiated the antibiofilm activity of polymyxin B and improved its bactericidal activity against the bacterial cells with established biofilms.</p><p><strong>Conclusions: </strong>Resveratrol potentiates the antibiofilm and antibacterial activity of polymyxin B against carbapenem-resistant A. baumannii. Polymyxin B used in combination with resveratrol may have better clinical efficacy than polymyxin B monotherapy in the treatment of carbapenem-resistant A. baumannii infections.</p>","PeriodicalId":15036,"journal":{"name":"Journal of Applied Microbiology","volume":" ","pages":""},"PeriodicalIF":3.2,"publicationDate":"2025-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145130795","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}