Pub Date : 2026-01-19DOI: 10.1016/j.micpath.2026.108310
Do-Hyeon Jung , Tae-Sung Lee , Yeong-Jun Kim , Yun-Ji Lee , In-Su Seo , Wan-Gyu Kim , Sang-Eun Jung , Ji-Yeong Kim , So-Yeon Ahn , Sung Jae Shin , Hong-Bum Koh , Eun-Jung Song , Ah-Ra Jang , Yu-Bin Lee , Jeon-Kyung Kim , Jong-Hwan Park
Mycobacterium abscessus (MAB), a rapidly growing nontuberculous mycobacterium, is a leading cause of chronic pulmonary infections, particularly among immunocompromised individuals. Owing to its intrinsic antibiotic resistance and persistence, MAB remains a therapeutic challenge. Activation of the NLRP3 inflammasome plays a central role in host inflammation by promoting IL-1β maturation and pyroptosis. Here, we investigated the anti-inflammatory effects of heat-killed Lactobacillus kunkeei NCHBL-003 (HK-LK), derived from honeybees, in MAB-induced pulmonary inflammation. In bone marrow-derived macrophages (BMDMs), HK-LK pretreatment suppressed MAB-induced gene expression of NLRP3, IL-1β, and TNF-α, and reduced cleavage of caspase-1 and IL-1β, without impairing bacterial clearance. In vivo, oral administration of HK-LK alleviated MAB-induced pulmonary inflammation and suppressed NLRP3-associated protein expression in lung tissues, while lung bacterial loads remained unchanged. Notably, similar anti-inflammatory effects were observed in both wild-type and TLR2-deficient mice, suggesting that TLR2 contributes but is not solely responsible for HK-LK–mediated protection. Gut microbiota analysis revealed significant Bray–Curtis dissimilarity following HK-LK treatment, despite unchanged α-diversity and UniFrac metrics. HK-LK reduced the abundance of Firmicutes, implying a role for gut microbiota modulation in its protective effects. Collectively, these findings demonstrate that HK-LK mitigates MAB-induced inflammation by modulating the NLRP3 inflammasome pathway and gut microbiota, highlighting its potential as an adjunctive strategy for mycobacterial infections.
{"title":"The postbiotic Lactobacillus kunkeei NCHBL-003 attenuates Mycobacterium abscessus-induced pulmonary inflammation by modulating IL-1β production","authors":"Do-Hyeon Jung , Tae-Sung Lee , Yeong-Jun Kim , Yun-Ji Lee , In-Su Seo , Wan-Gyu Kim , Sang-Eun Jung , Ji-Yeong Kim , So-Yeon Ahn , Sung Jae Shin , Hong-Bum Koh , Eun-Jung Song , Ah-Ra Jang , Yu-Bin Lee , Jeon-Kyung Kim , Jong-Hwan Park","doi":"10.1016/j.micpath.2026.108310","DOIUrl":"10.1016/j.micpath.2026.108310","url":null,"abstract":"<div><div><em>Mycobacterium abscessus</em> (MAB), a rapidly growing nontuberculous mycobacterium, is a leading cause of chronic pulmonary infections, particularly among immunocompromised individuals. Owing to its intrinsic antibiotic resistance and persistence, MAB remains a therapeutic challenge. Activation of the NLRP3 inflammasome plays a central role in host inflammation by promoting IL-1β maturation and pyroptosis. Here, we investigated the anti-inflammatory effects of heat-killed <em>Lactobacillus kunkeei</em> NCHBL-003 (HK-LK), derived from honeybees, in MAB-induced pulmonary inflammation. In bone marrow-derived macrophages (BMDMs), HK-LK pretreatment suppressed MAB-induced gene expression of NLRP3, IL-1β, and TNF-α, and reduced cleavage of caspase-1 and IL-1β, without impairing bacterial clearance. <em>In vivo</em>, oral administration of HK-LK alleviated MAB-induced pulmonary inflammation and suppressed NLRP3-associated protein expression in lung tissues, while lung bacterial loads remained unchanged. Notably, similar anti-inflammatory effects were observed in both wild-type and TLR2-deficient mice, suggesting that TLR2 contributes but is not solely responsible for HK-LK–mediated protection. Gut microbiota analysis revealed significant Bray–Curtis dissimilarity following HK-LK treatment, despite unchanged α-diversity and UniFrac metrics. HK-LK reduced the abundance of <em>Firmicutes</em>, implying a role for gut microbiota modulation in its protective effects. Collectively, these findings demonstrate that HK-LK mitigates MAB-induced inflammation by modulating the NLRP3 inflammasome pathway and gut microbiota, highlighting its potential as an adjunctive strategy for mycobacterial infections.</div></div>","PeriodicalId":18599,"journal":{"name":"Microbial pathogenesis","volume":"212 ","pages":"Article 108310"},"PeriodicalIF":3.5,"publicationDate":"2026-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146018727","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this work, Escherichia coli isolates from pig specimens were investigated for their virulence and drug-resistant profiles. Escherichia phage nasanit was isolated, characterized, and assessed its lytic activity against its host.
Methods and results
All tested E. coli isolates were identified as multidrug-resistant hybrid intestinal pathogenic E. coli/extraintestinal pathogenic E. coli (IPEC/ExPEC). The phage exhibited infectivity against E. coli isolates from porcine and bovine specimens by spot testing. Lytic activity assays against its host in simulated intestinal fluid at 39 °C and tryptic soy broth at 30 °C demonstrated a significant reduction in bacterial density at 30 °C. Genomic analysis confirmed the absence of undesirable genes, and comparative genomic analysis suggested that the phage constitutes a novel species within the Berlinvirus genus.
Conclusion
Escherichia phage nasanit demonstrates potential as a biosanitizing agent for mitigating livestock-associated colibacillosis in swine environments.
Impact statement
E. coli isolates harbored both IPEC and ExPEC virulence genes, coupled with a multidrug resistance, posing a significant risk for diverse disease in swine. Escherichia phage nasanit demonstrated lytic activity against pathogenic E. coli associated with swine and bovine diseases. The phage efficacy in eliminating the tested E. coli suggests its potential application for biosanitation in the swine industry.
{"title":"A novel Escherichia phage against multidrug-resistant hybrid IPEC/ExPEC Escherichia coli","authors":"Napakhwan Imklin , Kotryna Kvederavičiūtė , Wanchana Aesomnuk , Siwaret Arikit , Pornchalit Assavacheep , Eugenijus Šimoliūnas , Rujikan Nasanit","doi":"10.1016/j.micpath.2026.108308","DOIUrl":"10.1016/j.micpath.2026.108308","url":null,"abstract":"<div><h3>Aims</h3><div>In this work, <em>Escherichia coli</em> isolates from pig specimens were investigated for their virulence and drug-resistant profiles. <em>Escherichia</em> phage nasanit was isolated, characterized, and assessed its lytic activity against its host.</div></div><div><h3>Methods and results</h3><div>All tested <em>E. coli</em> isolates were identified as multidrug-resistant hybrid intestinal pathogenic <em>E. coli</em>/extraintestinal pathogenic <em>E. coli</em> (IPEC/ExPEC). The phage exhibited infectivity against <em>E. coli</em> isolates from porcine and bovine specimens by spot testing. Lytic activity assays against its host in simulated intestinal fluid at 39 °C and tryptic soy broth at 30 °C demonstrated a significant reduction in bacterial density at 30 °C. Genomic analysis confirmed the absence of undesirable genes, and comparative genomic analysis suggested that the phage constitutes a novel species within the <em>Berlinvirus</em> genus.</div></div><div><h3>Conclusion</h3><div><em>Escherichia</em> phage nasanit demonstrates potential as a biosanitizing agent for mitigating livestock-associated colibacillosis in swine environments.</div></div><div><h3>Impact statement</h3><div><em>E. coli</em> isolates harbored both IPEC and ExPEC virulence genes, coupled with a multidrug resistance, posing a significant risk for diverse disease in swine. <em>Escherichia</em> phage nasanit demonstrated lytic activity against pathogenic <em>E. coli</em> associated with swine and bovine diseases. The phage efficacy in eliminating the tested <em>E. coli</em> suggests its potential application for biosanitation in the swine industry.</div></div>","PeriodicalId":18599,"journal":{"name":"Microbial pathogenesis","volume":"212 ","pages":"Article 108308"},"PeriodicalIF":3.5,"publicationDate":"2026-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146018709","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-19DOI: 10.1016/j.micpath.2026.108285
Caiyun Yuan , Peipei Jin , Zhuo He , Jing Guo , Mingyu Xiong , Jiemeng Sun , Le Wang , Zixuan Wang , Ningxin Han , Wei Feng , Yunlong Hou , Hui Qi , Zhenhua Jia
Lianhua Qingwen (LHQW), a clinically validated herbal medicine containing Maxing Shigan Decoction (MXSGT) and others, shows broad efficacy in various respiratory disease. However, its regulatory role on the gut-lung axis, particularly the contribution of its MXSGT components, remains unexplored. This study employed a formula-disassembled approach to decipher this mechanism. Three preparations, including the complete LHQW prescription, LHQW excluding MXSGT components (LHQW-MXSGT), and MXSGT along, were administered to LPS-induced acute lung injury and DSS-induced ulcerative colitis to evaluate their therapeutic effects via the gut-lung axis. Pathological changes, mucosal barrier integrity, inflammatory cell infiltration and pro-inflammatory cytokine levels were evaluated by H&E staining, histochemical staining, immunofluorescence, ELISA, RT-qPCR and Western blot. Metagenomic analysis (16S rDNA sequencing) was conducted to examine their regulatory role of gut microbiota. Network pharmacology analysis and cellular validation was employed to explore their underlying mechanisms. Our analyses demonstrated that LHQW and MXSGT, but not LHQW-MXSGT, significantly attenuated lung/intestinal pathology damage, reduced pro-inflammatory cytokines (TNF-α, IL-1β, IL-6), and restored gut barrier proteins (ZO-1, Occludin, MUC2). LHQW/MXSGT suppressed pathogenic bacteria (Escherichia coli, Salmonella, Klebsiella pneumoniae) while enriching Akkermansia muciniphila, correlating with decreased systemic LPS. Network pharmacology and subsequent validation identified dual inhibition of TLR4/NF-κB and JAK2/STAT3 pathways as key mechanism of MXSGT.
In conclusion, MXSGT serves a pivotal pharmacologically active component of LHQW for its gut-lung axis regulation, acting through gut microbiota homeostasis restoration, intestinal barrier integrity maintenance, and anti-inflammatory signaling pathways, providing compelling scientific evidence supporting LHQW's potential therapeutic application in managing diseases characterized by comorbid gut and lung inflammation.
{"title":"Maxing Shigan decoction serves as a key component of Lianhua Qingwen in alleviating lung and gut injury by restoring gut microbiota homeostasis and inhibiting inflammation via TLR4/NF-κB and JAK2/STAT3 dual regulation","authors":"Caiyun Yuan , Peipei Jin , Zhuo He , Jing Guo , Mingyu Xiong , Jiemeng Sun , Le Wang , Zixuan Wang , Ningxin Han , Wei Feng , Yunlong Hou , Hui Qi , Zhenhua Jia","doi":"10.1016/j.micpath.2026.108285","DOIUrl":"10.1016/j.micpath.2026.108285","url":null,"abstract":"<div><div>Lianhua Qingwen (LHQW), a clinically validated herbal medicine containing Maxing Shigan Decoction (MXSGT) and others, shows broad efficacy in various respiratory disease. However, its regulatory role on the gut-lung axis, particularly the contribution of its MXSGT components, remains unexplored. This study employed a formula-disassembled approach to decipher this mechanism. Three preparations, including the complete LHQW prescription, LHQW excluding MXSGT components (LHQW-MXSGT), and MXSGT along, were administered to LPS-induced acute lung injury and DSS-induced ulcerative colitis to evaluate their therapeutic effects via the gut-lung axis. Pathological changes, mucosal barrier integrity, inflammatory cell infiltration and pro-inflammatory cytokine levels were evaluated by H&E staining, histochemical staining, immunofluorescence, ELISA, RT-qPCR and Western blot. Metagenomic analysis (16S rDNA sequencing) was conducted to examine their regulatory role of gut microbiota. Network pharmacology analysis and cellular validation was employed to explore their underlying mechanisms. Our analyses demonstrated that LHQW and MXSGT, but not LHQW-MXSGT, significantly attenuated lung/intestinal pathology damage, reduced pro-inflammatory cytokines (TNF-α, IL-1β, IL-6), and restored gut barrier proteins (ZO-1, Occludin, MUC2). LHQW/MXSGT suppressed pathogenic bacteria (<em>Escherichia coli, Salmonella, Klebsiella pneumoniae</em>) while enriching <em>Akkermansia muciniphila</em>, correlating with decreased systemic LPS. Network pharmacology and subsequent validation identified dual inhibition of TLR4/NF-κB and JAK2/STAT3 pathways as key mechanism of MXSGT.</div><div>In conclusion, MXSGT serves a pivotal pharmacologically active component of LHQW for its gut-lung axis regulation, acting through gut microbiota homeostasis restoration, intestinal barrier integrity maintenance, and anti-inflammatory signaling pathways, providing compelling scientific evidence supporting LHQW's potential therapeutic application in managing diseases characterized by comorbid gut and lung inflammation.</div></div>","PeriodicalId":18599,"journal":{"name":"Microbial pathogenesis","volume":"212 ","pages":"Article 108285"},"PeriodicalIF":3.5,"publicationDate":"2026-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146018796","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-19DOI: 10.1016/j.micpath.2026.108311
Bronwyn Lok , Nyok-Sean Lau , Noorizan Miswan , Alexander Chong Shu-Chien , Siti Nurfatimah Mohd Shahpudin , Hao-Ling Zhang , Doblin Sandai
The metabolic flexibility of Candida albicans enables the fungus to colonise and survive diverse niches in the host, contributing to its the pathogenicity in human infections. The effects of different carbon sources available to the fungus, such as glucose, fructose, and galactose, were investigated through growth studies, gene expression profiling, and real-time quantitative PCR (qPCR). The expression of certain carbon assimilation and antifungal drug resistance genes of the fungus was studied. The growth of the C. albicans cells were significantly slowed when galactose was used as their carbon source compared to the cells grown in glucose. Fluconazole was also found to have a stronger antifungal effect towards the cells grown in glucose and fructose compared to those grown in galactose. From the gene expression profiling, it was found that C. albicans undergoes a massive metabolic reorganization when grown on fructose and galactose compared to when it is grown in glucose, leading to changes in the expression of various carbon metabolic genes such as ICL1 (0.86 in fructose, −5.67 in galactose), MLS1 (1.08 in fructose), and MDH1 (0.93 in fructose, −1.14 in galactose). With a deeper understanding on how diet affects a Candida infection and the efficacy of the antifungal treatments against it, better treatment strategies could be developed to complement current antifungal medication. The usage of lower doses of antifungal drugs or the development of complementary antifungal strategies would also ameliorate the situation about the rise of antifungal drug resistance among pathogenic fungi.
{"title":"Gene expression profiling of the carbon pathways and virulence factors of Candida albicans in different carbon sources","authors":"Bronwyn Lok , Nyok-Sean Lau , Noorizan Miswan , Alexander Chong Shu-Chien , Siti Nurfatimah Mohd Shahpudin , Hao-Ling Zhang , Doblin Sandai","doi":"10.1016/j.micpath.2026.108311","DOIUrl":"10.1016/j.micpath.2026.108311","url":null,"abstract":"<div><div>The metabolic flexibility of <em>Candida albicans</em> enables the fungus to colonise and survive diverse niches in the host, contributing to its the pathogenicity in human infections. The effects of different carbon sources available to the fungus, such as glucose, fructose, and galactose, were investigated through growth studies, gene expression profiling, and real-time quantitative PCR (qPCR). The expression of certain carbon assimilation and antifungal drug resistance genes of the fungus was studied. The growth of the <em>C. albicans</em> cells were significantly slowed when galactose was used as their carbon source compared to the cells grown in glucose. Fluconazole was also found to have a stronger antifungal effect towards the cells grown in glucose and fructose compared to those grown in galactose. From the gene expression profiling, it was found that <em>C. albicans</em> undergoes a massive metabolic reorganization when grown on fructose and galactose compared to when it is grown in glucose, leading to changes in the expression of various carbon metabolic genes such as <em>ICL1</em> (0.86 in fructose, −5.67 in galactose), <em>MLS1</em> (1.08 in fructose), and <em>MDH1</em> (0.93 in fructose, −1.14 in galactose). With a deeper understanding on how diet affects a <em>Candida</em> infection and the efficacy of the antifungal treatments against it, better treatment strategies could be developed to complement current antifungal medication. The usage of lower doses of antifungal drugs or the development of complementary antifungal strategies would also ameliorate the situation about the rise of antifungal drug resistance among pathogenic fungi.</div></div>","PeriodicalId":18599,"journal":{"name":"Microbial pathogenesis","volume":"212 ","pages":"Article 108311"},"PeriodicalIF":3.5,"publicationDate":"2026-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146018751","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-18DOI: 10.1016/j.micpath.2026.108306
Damla Adsız , Nurcan Erbil , Ahmet İlçim
Plants can be used for different purposes, such as food, tea, and spices or for healing against various diseases. In this study, two different Kımı pickles, such as fermented with vinegar (SKT) and fermented with whey (PASKT), were produced. The antibacterial properties of both Kımı pickles were determined by MIC, MBC, and MTC and antibiofilm activity was determined by the crystal violet method. The bacterial microbiota of the Kımı pickle samples were determined by 16S metagenom analysis and the fungal microbiota by ITS metagenom analysis. As a result, the plant known as Kımı was systematically determined as Bunium cylindricum (Boiss. & Hohem.) Drude. PASKT exhibited the highest antibacterial activity against Bacillus licheniformis ATCC 14580, Klebsiella pneumoniae ATCC 33495, and Staphylococcus aureus ATCC 6538, while Staphylococcus aureus ATCC 6538 was the most sensitive to SKT. PASKT inhibited biofilm formation at a higher rate against Escherichia coli ATCC 8739 and Bacillus licheniformis ATCC 14580, while SKT exhibited higher antibiofilm activity against Klebsiella pneumoniae ATCC 33495 and Bacillus licheniformis ATCC 14580. The dominant bacterial genus in the PASKT was Bacteroides, whereas in the SKT it was Latilactobacillus. Dipodascus was the dominant genus in the PASKT fungal microbiota, while Penicillium was the dominant genus in the SKT fungal microbiota. In this study, whey was used as the fermentation medium for PASKT production. This has the potential to create an alternative for the utilization of whey, which is rich in nutrient content but is considered waste and can cause environmental pollution.
{"title":"Production of two Kımı pickles using the whey and vinegar as fermentation media and determination of bacterial and fungal microbiota, antibacterial and antibiofilm activities of Kımı pickles","authors":"Damla Adsız , Nurcan Erbil , Ahmet İlçim","doi":"10.1016/j.micpath.2026.108306","DOIUrl":"10.1016/j.micpath.2026.108306","url":null,"abstract":"<div><div>Plants can be used for different purposes, such as food, tea, and spices or for healing against various diseases. In this study, two different Kımı pickles, such as fermented with vinegar (SKT) and fermented with whey (PASKT), were produced. The antibacterial properties of both Kımı pickles were determined by MIC, MBC, and MTC and antibiofilm activity was determined by the crystal violet method. The bacterial microbiota of the Kımı pickle samples were determined by 16S metagenom analysis and the fungal microbiota by ITS metagenom analysis. As a result, the plant known as Kımı was systematically determined as <em>Bunium cylindricum</em> (Boiss. & Hohem.) Drude. PASKT exhibited the highest antibacterial activity against <em>Bacillus licheniformis</em> ATCC 14580, <em>Klebsiella pneumoniae</em> ATCC 33495, and <em>Staphylococcus aureus</em> ATCC 6538, while <em>Staphylococcus aureus</em> ATCC 6538 was the most sensitive to SKT. PASKT inhibited biofilm formation at a higher rate against <em>Escherichia coli</em> ATCC 8739 and <em>Bacillus licheniformis</em> ATCC 14580, while SKT exhibited higher antibiofilm activity against <em>Klebsiella pneumoniae</em> ATCC 33495 and <em>Bacillus licheniformis</em> ATCC 14580. The dominant bacterial genus in the PASKT was <em>Bacteroides</em>, whereas in the SKT it was <em>Latilactobacillus</em>. <em>Dipodascus</em> was the dominant genus in the PASKT fungal microbiota, while <em>Penicillium</em> was the dominant genus in the SKT fungal microbiota. In this study, whey was used as the fermentation medium for PASKT production. This has the potential to create an alternative for the utilization of whey, which is rich in nutrient content but is considered waste and can cause environmental pollution.</div></div>","PeriodicalId":18599,"journal":{"name":"Microbial pathogenesis","volume":"212 ","pages":"Article 108306"},"PeriodicalIF":3.5,"publicationDate":"2026-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146011280","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-16DOI: 10.1016/j.micpath.2026.108304
Yujie Shen , Li Kang , Ailing Xu, Guangmin Tu, Shuyan Wu
Toxin-antitoxin (TA) systems are distinct genetic modules, typically consisting of adjacent toxin and antitoxin genes, and are extensively prevalent in various bacterial species. These genetic elements play key roles in shaping bacterial physiology and pathogenicity, specifically in the regulation of growth dynamics, the mediation of stress responses, and the modulation of bacterial persistence and biofilm formation. TA systems are currently classified into eight types, type II and type VII stand out as pivotal modules for bacterial survival and have drawn much research interest. This review systematically dissects the multifaceted impacts of representative type II and type VII TA systems on the initiation, maturation, and dispersal stages of bacterial biofilm development, while comprehensively unraveling the underlying molecular mechanisms.
{"title":"Type II and type VII Toxin-antitoxin systems: an overview and their roles in bacterial biofilm development","authors":"Yujie Shen , Li Kang , Ailing Xu, Guangmin Tu, Shuyan Wu","doi":"10.1016/j.micpath.2026.108304","DOIUrl":"10.1016/j.micpath.2026.108304","url":null,"abstract":"<div><div>Toxin-antitoxin (TA) systems are distinct genetic modules, typically consisting of adjacent toxin and antitoxin genes, and are extensively prevalent in various bacterial species. These genetic elements play key roles in shaping bacterial physiology and pathogenicity, specifically in the regulation of growth dynamics, the mediation of stress responses, and the modulation of bacterial persistence and biofilm formation. TA systems are currently classified into eight types, type II and type VII stand out as pivotal modules for bacterial survival and have drawn much research interest. This review systematically dissects the multifaceted impacts of representative type II and type VII TA systems on the initiation, maturation, and dispersal stages of bacterial biofilm development, while comprehensively unraveling the underlying molecular mechanisms.</div></div>","PeriodicalId":18599,"journal":{"name":"Microbial pathogenesis","volume":"212 ","pages":"Article 108304"},"PeriodicalIF":3.5,"publicationDate":"2026-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145998519","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-16DOI: 10.1016/j.micpath.2026.108307
Igor Vasconcelos Rocha , Lamartine Rodrigues Martins , Maria Izabely Silva Pimentel , Renata Pessôa Germano Mendes , Ana Catarina de Souza Lopes
Background
Multidrug-resistant (MDR) Acinetobacter baumannii has emerged as a critical post-pandemic pathogen, combining antimicrobial resistance with biofilm formation, severely complicating infection control. We aimed to characterize the genetic mechanisms of β-lactams resistance and biofilm-forming capacity of MDR A. baumannii isolates from a Brazilian tertiary hospital, in the post-COVID-19 pandemic period.
Methods
A. baumannii isolates were collected from various clinical specimens between 2023/2024. Species identification was performed using the Phoenix BD® system. Antimicrobial susceptibility testing was performed by broth microdilution. β-lactamase genes were investigated by PCR, and biofilm formation was quantified using crystal violet assay. Growth kinetics were analyzed spectrophotometrically.
Results
Among 78 isolates, 98.7 % exhibited MDR profiles while remaining susceptible to colistin. Strong biofilm production occurred in 71.8 % of isolates, particularly from rectal swabs. Dominant resistance genes included blaOXA-23 (66.7 %), blaOXA-24 (19.2 %), and blaOXA-143 (12.9 %), with blaNDM-1 in 3.9 %. Isaba1 was associated with blaOXA-23 (44.2 %) and blaADC (92.3 %). The bap gene was detected in 28.2 % of the isolates, while blaKPC/GES/IMP/SPM/PER-1 were absent. Biofilm-forming groups displayed distinct growth patterns.
Conclusion
Our study demonstrates that most A. baumannii isolates exhibit MDR profiles and robust biofilm formation. The widespread presence of β-lactamase genes and biofilm-producing strains underscores the necessity for enhanced molecular surveillance and biofilm-focused infection control measures in critical care units. These findings provide valuable insights into the genetic mechanisms driving resistance and biofilm formation in post-pandemic clinical settings. To mitigate the persistence and spread of high-risk MDR clones, hospitals should integrate genetic resistance profiling and biofilm-targeted strategies into infection control protocols.
{"title":"Post-pandemic molecular epidemiology of β-lactam resistance and biofilm formation in multidrug-resistant Acinetobacter baumannii from a Brazilian tertiary hospital","authors":"Igor Vasconcelos Rocha , Lamartine Rodrigues Martins , Maria Izabely Silva Pimentel , Renata Pessôa Germano Mendes , Ana Catarina de Souza Lopes","doi":"10.1016/j.micpath.2026.108307","DOIUrl":"10.1016/j.micpath.2026.108307","url":null,"abstract":"<div><h3>Background</h3><div>Multidrug-resistant (MDR) <em>Acinetobacter baumannii</em> has emerged as a critical post-pandemic pathogen, combining antimicrobial resistance with biofilm formation, severely complicating infection control. We aimed to characterize the genetic mechanisms of β-lactams resistance and biofilm-forming capacity of MDR <em>A. baumannii</em> isolates from a Brazilian tertiary hospital, in the post-COVID-19 pandemic period.</div></div><div><h3>Methods</h3><div><em>A. baumannii</em> isolates were collected from various clinical specimens between 2023/2024. Species identification was performed using the Phoenix BD® system. Antimicrobial susceptibility testing was performed by broth microdilution. β-lactamase genes were investigated by PCR, and biofilm formation was quantified using crystal violet assay. Growth kinetics were analyzed spectrophotometrically.</div></div><div><h3>Results</h3><div>Among 78 isolates, 98.7 % exhibited MDR profiles while remaining susceptible to colistin. Strong biofilm production occurred in 71.8 % of isolates, particularly from rectal swabs. Dominant resistance genes included <em>bla</em><sub>OXA-23</sub> (66.7 %), <em>bla</em><sub>OXA-24</sub> (19.2 %), and <em>bla</em><sub>OXA-143</sub> (12.9 %), with <em>bla</em><sub>NDM-1</sub> in 3.9 %. <em>Isaba1</em> was associated with <em>bla</em><sub>OXA-23</sub> (44.2 %) and <em>bla</em><sub>ADC</sub> (92.3 %). The <em>bap</em> gene was detected in 28.2 % of the isolates, while <em>bla</em><sub>KPC/GES/IMP/SPM/PER-1</sub> were absent. Biofilm-forming groups displayed distinct growth patterns.</div></div><div><h3>Conclusion</h3><div>Our study demonstrates that most <em>A. baumannii</em> isolates exhibit MDR profiles and robust biofilm formation. The widespread presence of β-lactamase genes and biofilm-producing strains underscores the necessity for enhanced molecular surveillance and biofilm-focused infection control measures in critical care units. These findings provide valuable insights into the genetic mechanisms driving resistance and biofilm formation in post-pandemic clinical settings. To mitigate the persistence and spread of high-risk MDR clones, hospitals should integrate genetic resistance profiling and biofilm-targeted strategies into infection control protocols.</div></div>","PeriodicalId":18599,"journal":{"name":"Microbial pathogenesis","volume":"212 ","pages":"Article 108307"},"PeriodicalIF":3.5,"publicationDate":"2026-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145998574","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Emerging multidrug-resistant (MDR) and extensively drug-resistant (XDR) Acinetobacter baumanii is a serious challenge in hospital settings. Biofilm formation is one of these bacteria's most crucial mechanisms of antibiotic resistance. Given the ineffectiveness of common antibiotics against MDR, XDR, and biofilm-forming A. baumannii, the healthcare system must use new strategies to combat A. baumannii biofilm. This study aimed to provide an overview of the in vitro, in vivo, and ex vivo combination therapy of phages and antibiotics for combating A. baumanii biofilms. Most studies suggest that pairing antibiotics with phages could help break down A. baumannii biofilms and treat infections caused by these hard-to-beat superbugs, especially when using cocktail phages and colistin to inhibit biofilm formation or eradicate biofilms. Many limitations of phage therapy can be overcome by combining phage therapy with antibiotics. Additionally, protein-derived phages have been proposed as a promising alternative or complementary approach to conventional therapies, demonstrating significant antibacterial activity. When used in combination with antibiotics, they may enhance treatment efficacy by reducing the spread of antibiotic-resistant A. baumannii and effectively eliminating their biofilms. Combining antibiotics with phage therapy may offer an effective strategy to disrupt A. baumannii biofilms in laboratory settings and improve treatment outcomes for patients with drug-resistant infections.
{"title":"Pairing antibiotics with phages: A new strategy to tackle biofilms of drug-resistant Acinetobacter baumannii—insights from in vitro and in vivo studies","authors":"Majid Taati Moghadam , Mahsa Ziasistani , Faeze Mahdiun , Mohammad Hossein Sobhanipoor , Massoumeh Ghasemi , Elham Isaei , Mahsa Kiaei","doi":"10.1016/j.micpath.2026.108290","DOIUrl":"10.1016/j.micpath.2026.108290","url":null,"abstract":"<div><div>Emerging multidrug-resistant (MDR) and extensively drug-resistant (XDR) <em>Acinetobacter baumanii</em> is a serious challenge in hospital settings. Biofilm formation is one of these bacteria's most crucial mechanisms of antibiotic resistance. Given the ineffectiveness of common antibiotics against MDR, XDR, and biofilm-forming <em>A. baumannii</em>, the healthcare system must use new strategies to combat <em>A. baumannii</em> biofilm. This study aimed to provide an overview of the in vitro, in vivo, and ex vivo combination therapy of phages and antibiotics for combating <em>A. baumanii</em> biofilms. Most studies suggest that pairing antibiotics with phages could help break down <em>A. baumannii</em> biofilms and treat infections caused by these hard-to-beat superbugs, especially when using cocktail phages and colistin to inhibit biofilm formation or eradicate biofilms. Many limitations of phage therapy can be overcome by combining phage therapy with antibiotics. Additionally, protein-derived phages have been proposed as a promising alternative or complementary approach to conventional therapies, demonstrating significant antibacterial activity. When used in combination with antibiotics, they may enhance treatment efficacy by reducing the spread of antibiotic-resistant <em>A. baumannii</em> and effectively eliminating their biofilms. Combining antibiotics with phage therapy may offer an effective strategy to disrupt <em>A. baumannii</em> biofilms in laboratory settings and improve treatment outcomes for patients with drug-resistant infections.</div></div>","PeriodicalId":18599,"journal":{"name":"Microbial pathogenesis","volume":"213 ","pages":"Article 108290"},"PeriodicalIF":3.5,"publicationDate":"2026-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145994438","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-14DOI: 10.1016/j.micpath.2026.108291
He Yang, Yaqian Gu, Yingying Dong, Huan Sun, Shuangshuang Liufu, Haiyan Xu, Ke Du, Linxiu Peng, Weichen Xu, Lili Lin, Tong Xie, Jinjun Shan, Xia Zhao
Respiratory syncytial virus (RSV) infection triggers excessive inflammation, contributing to disease severity. Baicalin exerts therapeutic effects against RSV infection by inhibiting viral replication and alleviating inflammation. However, the mechanisms underlying its immunoregulatory during RSV infection remain unclear. Here we found that baicalin alleviated RSV induced inflammation by regulating the macrophage immunometabolism. To investigate metabolic modulation, metabolomic analysis was performed, revealing an obvious reversal in the metabolic profile by baicalin administration. Further metabolic flux analysis using isotope tracers demonstrated that baicalin suppressed the accumulation of lactate and succinate induced by RSV infection. Mechanistically, baicalin inhibited glycolytic metabolism and succinate driven hypoxia-inducible factor 1α (HIF-1α) signaling during RSV infection, thereby suppressing NLR family, pyrin domain containing protein 3 (NLRP3) activation and reducing IL-1β release. The effects were validated in vitro using a glycolysis activator to confirm the suppression of glycolytic metabolism, and through co-treatment with dimethylsuccinate and RSV to verify the involvement of HIF-1α-mediated hypoxia pathway. Final targeting for baicalin at pyruvate kinase M2 (PKM2) was confirmed via molecular docking and limited proteolysis-coupled mass spectrometry. Taken together, these data elucidate a mechanism of baicalin through regulatory immunometabolism of macrophage to alleviate RSV-induced inflammation, which have critical roles in the treatment of RSV infection.
{"title":"Baicalin inhibits macrophage glycolysis and succinate-driven HIF-1α signaling by targeting PKM2 to alleviate RSV-induced inflammation.","authors":"He Yang, Yaqian Gu, Yingying Dong, Huan Sun, Shuangshuang Liufu, Haiyan Xu, Ke Du, Linxiu Peng, Weichen Xu, Lili Lin, Tong Xie, Jinjun Shan, Xia Zhao","doi":"10.1016/j.micpath.2026.108291","DOIUrl":"10.1016/j.micpath.2026.108291","url":null,"abstract":"<p><p>Respiratory syncytial virus (RSV) infection triggers excessive inflammation, contributing to disease severity. Baicalin exerts therapeutic effects against RSV infection by inhibiting viral replication and alleviating inflammation. However, the mechanisms underlying its immunoregulatory during RSV infection remain unclear. Here we found that baicalin alleviated RSV induced inflammation by regulating the macrophage immunometabolism. To investigate metabolic modulation, metabolomic analysis was performed, revealing an obvious reversal in the metabolic profile by baicalin administration. Further metabolic flux analysis using isotope tracers demonstrated that baicalin suppressed the accumulation of lactate and succinate induced by RSV infection. Mechanistically, baicalin inhibited glycolytic metabolism and succinate driven hypoxia-inducible factor 1α (HIF-1α) signaling during RSV infection, thereby suppressing NLR family, pyrin domain containing protein 3 (NLRP3) activation and reducing IL-1β release. The effects were validated in vitro using a glycolysis activator to confirm the suppression of glycolytic metabolism, and through co-treatment with dimethylsuccinate and RSV to verify the involvement of HIF-1α-mediated hypoxia pathway. Final targeting for baicalin at pyruvate kinase M2 (PKM2) was confirmed via molecular docking and limited proteolysis-coupled mass spectrometry. Taken together, these data elucidate a mechanism of baicalin through regulatory immunometabolism of macrophage to alleviate RSV-induced inflammation, which have critical roles in the treatment of RSV infection.</p>","PeriodicalId":18599,"journal":{"name":"Microbial pathogenesis","volume":" ","pages":"108291"},"PeriodicalIF":3.5,"publicationDate":"2026-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145989970","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-14DOI: 10.1016/j.micpath.2026.108295
Nahla Alsayd Bouqellah
The main objective of the study was to attain improved effectiveness against various bacterial and fungal infections, tackling the widespread problem of multidrug resistance. The study presents the development and evaluation of a hybrid antimicrobial protein created by combining chitinase and sonorensin (HyChiSono). The hybrid protein HyChiSono, a 49.3 kDa chitinase–sonorensin fusion protein, was engineered, expressed in E. coli BL21(DE3), and purified to > 95 % homogeneity. Independent folding of each domain linked by a flexible (GGGGS) spacer was revealed by AlphaFold modelling; a highly ordered α/β structure was confirmed by far-UV CD. HyChiSono exhibited bactericidal activity, as assessed through well diffusion assays, membrane damage assays, and transmission electron microscopy (TEM). Quantitatively, HyChiSono demonstrated robust antibacterial activity, with recorded zones of inhibition (ZOIs) against Gram-positive Staphylococcus aureus (MIC 8 μg/mL; ZOI 17.0 ± 0.3 mm), Listeria monocytogenes (MIC 16 μg/mL; ZOI 19.3 ± 0.5 mm), and Gram-negative Escherichia coli (MIC 4 μg/mL; ZOI 18.5 ± 0.5 mm) and Salmonella enterica serovar Typhi (MIC 2 μg/mL; ZOI 18.0 ± 0.7 mm), outperforming native sonorensin by a factor of 2–4. SYTOX-green uptake and TEM demonstrated rapid membrane permeabilization and peptidoglycan thinning in both cell envelopes. Cell-wall targeting was rationalized by docking scores of −6.7 and −6.4 kcal/mol against N-acetyl-glucosamine and chitin. In addition to its antibacterial properties, the antifungal assays of hybrid protein exhibited 64.7 % growth inhibition of Fusarium oxysporum and 45.9 % against Alternaria solani, superior to standalone chitinase (41 % and 37 %, respectively). The bifunctional HyChiSono construct is offered as a single-molecule platform to combat multidrug-resistant bacteria and phytopathogenic fungi.
{"title":"Engineering a hybrid chitinase-sonorensin fusion protein for enhanced antibacterial and antifungal activity","authors":"Nahla Alsayd Bouqellah","doi":"10.1016/j.micpath.2026.108295","DOIUrl":"10.1016/j.micpath.2026.108295","url":null,"abstract":"<div><div>The main objective of the study was to attain improved effectiveness against various bacterial and fungal infections, tackling the widespread problem of multidrug resistance. The study presents the development and evaluation of a hybrid antimicrobial protein created by combining chitinase and sonorensin (HyChiSono). The hybrid protein HyChiSono, a 49.3 kDa chitinase–sonorensin fusion protein, was engineered, expressed in <em>E. coli</em> BL21(DE3), and purified to > 95 % homogeneity. Independent folding of each domain linked by a flexible (GGGGS) spacer was revealed by AlphaFold modelling; a highly ordered α/β structure was confirmed by far-UV CD. HyChiSono exhibited bactericidal activity, as assessed through well diffusion assays, membrane damage assays, and transmission electron microscopy (TEM). Quantitatively, HyChiSono demonstrated robust antibacterial activity<em>, with recorded zones of inhibition (ZOIs) against Gram-positive Staphylococcus aureus</em> (MIC 8 μg/mL; ZOI 17.0 ± 0.3 mm)<em>, Listeria monocytogenes</em> (MIC 16 μg/mL; ZOI 19.3 ± 0.5 mm)<em>, and Gram-negative Escherichia coli</em> (MIC 4 μg/mL; ZOI 18.5 ± 0.5 mm) <em>and Salmonella enterica serovar Typhi</em> (MIC 2 μg/mL; ZOI 18.0 ± 0.7 mm)<em>,</em> outperforming native sonorensin by a factor of 2–4. SYTOX-green uptake and TEM demonstrated rapid membrane permeabilization and peptidoglycan thinning in both cell envelopes. Cell-wall targeting was rationalized by docking scores of −6.7 and −6.4 kcal/mol against N-acetyl-glucosamine and chitin. In addition to its antibacterial properties, the antifungal assays of hybrid protein exhibited 64.7 % growth inhibition of <em>Fusarium oxysporum</em> and 45.9 % against <em>Alternaria solani</em>, superior to standalone chitinase (41 % and 37 %, respectively). The bifunctional HyChiSono construct is offered as a single-molecule platform to combat multidrug-resistant bacteria and phytopathogenic fungi.</div></div>","PeriodicalId":18599,"journal":{"name":"Microbial pathogenesis","volume":"212 ","pages":"Article 108295"},"PeriodicalIF":3.5,"publicationDate":"2026-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145989995","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}