Microbiology spectrum最新文献

{"title":"Electron transport chain: a crucial target of luteolin in combating <i>Trueperella pyogenes</i>.","authors":"Yuru Guo, Yueting Guo, Ruxia Wang, Simiao Wang, Hanyu Zhao, Yingyu Wang, Shengli Niu, Chunlian Tian, Mingchun Liu","doi":"10.1128/spectrum.01985-26","DOIUrl":"https://doi.org/10.1128/spectrum.01985-26","url":null,"abstract":"<p><p><i>Trueperella pyogenes</i> is an opportunistic pathogen capable of causing infections in both domestic and wild animals. Furthermore, the dissemination of resistance genes has resulted in varying degrees of antimicrobial resistance among <i>T. pyogenes</i> isolates. Therefore, it is necessary to develop new anti-<i>T</i>. <i>pyogenes</i> drugs to address its increasing resistance. Luteolin, a natural flavonoid, has been found to exhibit good antibacterial activity against <i>T. pyogenes</i> in our previous research. This study aims to utilize high-throughput proteomics technology to identify potential novel targets and illuminate the action mechanism of luteolin. Our results indicated that luteolin could target electron transport chain complexes I, II, and V to inhibit the oxidative phosphorylation of <i>T. pyogenes</i>. Besides, luteolin could inhibit the enzyme activities involved in glycolysis and the tricarboxylic acid cycle, which eventually leads to a decrease in reduced hydrogen supplied to the electron transport chain and reduces the content of intracellular adenosine triphosphate. Based on the high-throughput proteomic analysis and multiple experimental results, the inhibition of electron transport chain complexes appears to be a significant mechanism by which luteolin exerts its antibacterial effect against <i>T. pyogenes</i>. Overall, this study provides a new insight into the anti-<i>T</i>. <i>pyogenes</i> mechanism of luteolin and offers new targets to develop anti-<i>T</i>. <i>pyogenes</i> drugs.</p><p><strong>Importance: </strong><i>Trueperella pyogenes</i> is an opportunistic pathogen that can cause suppurative infections in multiple animals. Its existing resistance may bring challenges to anti-infection therapy. As a promising natural antibacterial agent, luteolin shows potent activity against this bacterium. This study revealed that luteolin disrupts bacterial energy metabolism by targeting electron transport chain complexes, thereby reducing intracellular adenosine triphosphate content. Our findings expanded the new antibacterial mechanism of luteolin and identified novel targets. This work provides valuable references for developing novel drugs against drug-resistant bacterial infections by targeting the electron transport chain.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":" ","pages":"e0198526"},"PeriodicalIF":4.1,"publicationDate":"2026-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149195272","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Environmental determinants of phenazine- and 2,4-diacetylphloroglucinol-producing <i>Pseudomonas</i> in the wheat rhizosphere across a precipitation gradient.","authors":"Olga Mavrodi, Alexander Panchenko, Oleksandr Dykhovychnyi, Ian Leslie, Lyudmyla Barannyk, Linda Thomashow, David Weller, Dmitri Mavrodi","doi":"10.1128/spectrum.04188-25","DOIUrl":"https://doi.org/10.1128/spectrum.04188-25","url":null,"abstract":"&lt;p&gt;&lt;p&gt;The Columbia Plateau of the Inland Pacific Northwest (IPNW) encompasses one of North America's largest dryland wheat production regions, where soil moisture strongly influences plant growth, health, and rhizosphere microbial communities. Two ecologically and genetically distinct groups of the &lt;i&gt;Pseudomonas fluorescens&lt;/i&gt; complex naturally suppress soilborne wheat pathogens in IPNW fields by producing either phenazine-1-carboxylic acid (Phz+) or 2,4-diacetylphloroglucinol (Phl+). To determine how precipitation and associated soil factors shape the abundance of these bacteria, we analyzed wheat root samples from commercial fields spanning a precipitation gradient across the Columbia Plateau. We quantified pairwise relationships among environmental variables using Spearman correlations and constructed a correlation network to visualize patterns of association. Network analysis revealed that precipitation influences soil properties indirectly, with organic matter, clay content, cation exchange capacity, and pH forming an interconnected cluster of correlated variables. Wheat rhizosphere colonization frequency by Phz+ pseudomonads was primarily associated with soil pH, which correlated with precipitation through its effects on weathering and organic matter accumulation, whereas colonization frequency of Phl+ pseudomonads showed weaker associations with abiotic variables. Phz+ pseudomonads were favored in neutral to alkaline, coarse soils typical of the low-precipitation zone, whereas Phl+ populations thrived in wetter, organic-rich soils with lower pH. These findings highlight soil pH as a key environmental filter mediating precipitation-driven differences in &lt;i&gt;Pseudomonas&lt;/i&gt; populations and suggest that biotic interactions and plant selection further modulate root colonization. Understanding how these agriculturally important microbial functional groups respond to moisture regimes provides insight into the sustainability of disease-suppressive microbiomes in the IPNW.IMPORTANCEDryland wheat-based production systems of the Inland Pacific Northwest are highly vulnerable to changing precipitation patterns that affect crop productivity, soilborne pathogens, and soil microbial ecology. This study reveals how long-term rainfall gradients influence the balance between two groups of beneficial &lt;i&gt;Pseudomonas&lt;/i&gt; that protect wheat from root diseases. We show that soil pH, closely linked to rainfall, organic matter, and mineral weathering, is a key abiotic factor controlling the presence of phenazine-producing bacteria in dryland wheat grown in low-precipitation zone soils. In contrast, 2,4-diacetylphloroglucinol producers dominate in wetter, organic-rich environments. These insights help explain how beneficial microbiomes adapt to environmental constraints and identify soil conditions that promote natural disease suppression. Understanding these mechanisms will aid in predicting microbiome resilience and guiding management strategies to maintain whe","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":" ","pages":"e0418825"},"PeriodicalIF":4.1,"publicationDate":"2026-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149195284","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Integrated assays with <i>in silico</i> analyses indicated the biocontrol potential of <i>Bacillus velezensis</i> BJ1 against fungal phytopathogens.","authors":"Yonghua Li, Manawaduge Ayesha Madushani, Mei Liu, Chenfang Wang, Hui Wang, Xinghong Li, Kevin David Hyde, Wei Zhang, Jiye Yan","doi":"10.1128/spectrum.00944-26","DOIUrl":"https://doi.org/10.1128/spectrum.00944-26","url":null,"abstract":"<p><p>Fungal diseases continue to devastate global fruit and vegetable production, emphasizing the urgent need for sustainable disease management approaches such as microbial biocontrol. In this study, a locally isolated bacterial strain was identified as <i>Bacillus velezensis</i> BJ1 based on phylogenomic analysis, and its biocontrol potential was evaluated using <i>in vitro</i>, <i>in vivo</i>, and <i>in planta</i> assays combined with <i>in silico</i> analysis. <i>In vitro</i> dual culture assay demonstrated broad-spectrum antagonistic activity of the BJ1 strain against 59 isolates of common fungal phytopathogens affecting fruit trees and vegetables, with inhibition rates ranging from 53.76% to 98.45%. The strongest suppression was observed against <i>Diaporthe sojae</i> OSS① (98.45%), followed by <i>D. sojae</i> B2 JZB320190 (89.15%), <i>Cladosporium cladosporioides</i> TZZG-11-A-S1 (85.37%), <i>C. cladosporioides</i> TZZG-6-A-S1 (85.22%), <i>D. sojae</i> JZB320189 (80.62%), and <i>D. eres</i> TZZG36-S1 (80.62%). Detached tomato leaf assays against the gray mold pathogen <i>Botrytis cinerea</i> demonstrated that BJ1 achieved high control efficiencies of 87.87% and 68.95% for therapeutic and preventive treatments, respectively, at a concentration of 1 × 10⁷ CFU/mL. Furthermore, a BJ1-based water-dispersible granule formulation applied at 2 × 10⁸ CFU/mL achieved an 80.48% disease inhibition rate under greenhouse conditions. Genome mining identified 13 biosynthetic gene clusters encoding antimicrobial compounds, suggesting a genetic basis for BJ1's biocontrol activity. Overall, <i>B. velezensis</i> BJ1 demonstrates strong potential for development as an effective biocontrol product, offering both genomic insights and practical application in sustainable disease management.</p><p><strong>Importance: </strong>Biological control is a sustainable strategy for managing plant pathogens while reducing the environmental and health risks associated with chemical pesticides. However, their practical application is often limited by poor environmental adaptation, limited broad-spectrum activity, and inconsistent efficacy. <i>Bacillus velezensis</i> BJ1, a locally isolated strain, exhibited broad antagonistic activity against 59 isolates of common phytopathogens across eight host plants. Further, it exhibited consistent <i>in vivo</i> and <i>in planta</i> efficacy against the highly virulent pathogen <i>Botrytis cinerea</i> under both protective and therapeutic treatments, highlighting its potential for both disease prevention and post-infection suppression. Whole-genome phylogenomic analysis confirmed its precise taxonomic identity, and genome mining suggested multiple biosynthetic gene clusters potentially associated with antifungal activity and plant protection. This study highlights BJ1 as a robust and eco-friendly candidate for sustainable disease management.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":" ","pages":"e0094426"},"PeriodicalIF":4.1,"publicationDate":"2026-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149182529","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparison of QuantiFERON-TB Gold Plus results using ELISA and automated CLIA detection: a 39,000-sample real-world study.","authors":"Federica Sorella, Vincenzo Ferraro, Paolo Caiazza, Miriam Ciccarelli, Giuliana Germinario, Alessia Cantiani, Giulia Lombardi, Francesco Bisognin, Paola Dal Monte","doi":"10.1128/spectrum.02295-26","DOIUrl":"https://doi.org/10.1128/spectrum.02295-26","url":null,"abstract":"<p><p>QuantiFERON-TB Gold Plus (QFT-Plus) is a widely used interferon-γ release assay (IGRA) for the diagnosis of <i>Mycobacterium tuberculosis</i> infection. Recent advances introduced fully automated chemiluminescence immunoassay (CLIA) platforms as alternatives to conventional enzyme-linked immunosorbent assay (ELISA), potentially improving analytical performance and laboratory workflow. This study compared ELISA- and CLIA-based QFT-Plus assays using both lyophilized and liquid conjugate formulations in routine clinical practice. This retrospective study included 39,604 QFT-Plus assays performed during three distinct 1-year periods: 2019 (ELISA), 2023 (CLIA with lyophilized conjugate), and 2024 (CLIA with liquid conjugate). Test results were classified as positive, negative, or indeterminate. Indeterminate results were further categorized as due to low mitogen response (LMR) or high Nil value (HNV). Indeterminate results significantly decreased from 6.5% (777/11,885) with ELISA to 3.1% (394/12,690) with CLIA test using lyophilized conjugate and 3.1% (470/15,029) of CLIA tests using the liquid conjugate (<i>P</i> < 0.0001). Positive results accounted for 10.6 (1,254/11,885), 10.3 (1,312/12,690), and 9.0% (1,355/15,029) of tests, respectively. Among indeterminate results, LMR accounted for 97.3% (756/777) with ELISA, whereas HNV accounted for 27.4 (108/394) and 16.8% (79/470) with the lyophilized- and liquid-conjugate CLIA methods, respectively. Agreement between TB1 and TB2 responses was consistently high across all methods (98.5-98.8%; <i>κ</i> = 0.92). CLIA-based QFT-Plus assays were significantly associated with a lower proportion of indeterminate results while maintaining an excellent TB1/TB2 concordance compared with ELISA. These findings support fully automated CLIA platforms as a robust and efficient alternative to conventional ELISA for high-throughput tuberculosis screening and routine clinical diagnostics.</p><p><strong>Importance: </strong>This study provides a large real-world evaluation of QuantiFERON-TB Gold Plus testing across different analytical platforms, including more than 39,000 tests performed in routine clinical practice. The transition from conventional enzyme-linked immunosorbent assay (ELISA) to automated chemiluminescence immunoassay (CLIA) was associated with an approximately 50% decrease in indeterminate results from 6.5 to 3.1%, with similarly low rates observed using both lyophilized and liquid conjugate formulations. Beyond documenting this substantial reduction, our study reveals a marked difference in the causes of indeterminate results: low mitogen response predominated with ELISA, whereas high Nil values accounted for a larger proportion of indeterminate results with CLIA. These findings, interpreted together with our previous paired-sample comparison, indicate that differences in quantitative IFN-γ measurement across platforms may affect how samples are classified against fixed decision thresholds.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":" ","pages":"e0229526"},"PeriodicalIF":4.1,"publicationDate":"2026-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149183239","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Histones and nucleoid-associated proteins in <i>Methanosarcina acetivorans</i> mediate recovery from stress and stasis.","authors":"Alienor S Baskevitch, Dipti D Nayak","doi":"10.1128/spectrum.02785-26","DOIUrl":"https://doi.org/10.1128/spectrum.02785-26","url":null,"abstract":"<p><p>Many archaea encode histones in tandem with <b><u>n</u></b>ucleoid-<b><u>a</u></b>ssociated <b><u>p</u></b>roteins (NAPs), but the functional overlap between these two classes of non-specific <b><u>D</u></b>NA-<b><u>b</u></b>inding <b><u>p</u></b>roteins (DBPs) is not well studied. Most <i>in vivo</i> studies of DBPs have been conducted with archaea that only encode histones or NAPs. Here, we characterize the endogenous function of the two families of DBPs in a methanogen, <i>Methanosarcina acetivorans</i>, that encodes a histone and two copies of an archaea-specific NAP called <b><u>m</u></b>ethanogen <b><u>c</u></b>hromatin Protein 1 (MC1). In <i>M. acetivorans,</i> we found that each DBP is individually dispensable, but at least one copy of <i>mc1</i> appears to be essential. By and large, the single- and double-DBP knockouts phenocopy the wild-type strain under optimal laboratory growth conditions. Remarkably, mutants lacking the histone, one copy of MC1, or both recover faster than wild-type after being subjected to UV shock or long periods of growth stasis. Overexpression of the DBPs leads to a delay in growth recovery after extended periods in stationary phase, which is abrogated by introducing point mutations in DNA-binding residues. Together, our data suggest that histones and MC1 proteins have partially overlapping roles in <i>M. acetivorans</i>, one of which might be genome maintenance when growth has stalled or stopped.IMPORTANCEThough it is known that many archaea encode histones in tandem with archaea-specific <b><u>n</u></b>ucleoid-<b><u>a</u></b>ssociated <b><u>p</u></b>roteins (NAPs), the interplay between these two classes of <b><u>D</u></b>NA-<b><u>b</u></b>inding <b><u>p</u></b>roteins (DBPs) <i>in vivo</i> is not known. Most studies on archaeal DBPs have focused either on archaea known to form histone-based chromatin or on strains that lack histones and compact their genomes exclusively with archaea-specific NAPs. Our study, therefore, fills an important gap in the literature by characterizing DBPs in a model methanogen, <i>Methanosarcina acetivorans</i>, which encodes both histones and archaea-specific NAPs. While no DBP is essential, at least one copy of MC1 appears to be needed, likely for genome compaction. In addition, mutants lacking DBPs had a growth advantage after being subjected to stressors or long periods of growth stasis, indicating that DBPs likely function in genome maintenance when growth has stalled or stopped.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":" ","pages":"e0278526"},"PeriodicalIF":4.1,"publicationDate":"2026-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149182361","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hemagglutinin and fusion proteins precede measles virus ribonucleoproteins and marshal cell-to-cell spread in airway epithelium.","authors":"Stephanie E Clark, Justin W Kaufman, Kalpana Yadav, Roberto Cattaneo, Brajesh K Singh, Patrick L Sinn","doi":"10.1128/spectrum.02297-26","DOIUrl":"https://doi.org/10.1128/spectrum.02297-26","url":null,"abstract":"<p><p>Measles virus (MeV) is the most contagious human respiratory pathogen. To understand how it spreads in the airways, we infected well-differentiated primary cultures of human airway epithelial cells (HAE). We discovered that the MeV attachment protein (hemagglutinin, H), the fusion (F) protein, and the assembly organizer protein (matrix, M) reach newly infected cells ahead of, and independently from, the replicative complex proteins. To characterize the mechanisms of MeV spread, we generated a replication-deficient adenoviral vector expressing the MeV M, F, and H proteins in a doxycycline-inducible manner. This viral vector formed infectious centers that preserved epithelial function like those from MeV infection. To further dissect this process, we generated Ad vectors expressing individual MeV proteins, termed Ad-M, Ad-F, and Ad-H. Transduction of HAE with single, double, and triple Ad vector combinations revealed that Ad-F and Ad-H are necessary and sufficient to form MeV-like infectious centers. MeV enters and spreads within airway epithelia via H protein binding to adherens junction protein, nectin-4. To disrupt spread, we introduced the point mutation H^Y543A, a mutation previously described to inhibit nectin-4 binding, in the Ad-H vector. Co-transduction of Ad-F and Ad-H^Y543A did not result in MeV-like infectious center formation. Finally, we assessed whether the MeV-related paramyxovirus Nipah (NiV) attachment and fusion proteins (G and F, respectively) support cell-to-cell spread. Co-transduction of HAE with Ad-NiV-G and Ad-NiV-F did not result in infectious center formation, suggesting that decoupling of the membrane fusion apparatus function from replication is a unique feature of the MeV envelope glycoproteins.IMPORTANCEMeasles virus is a highly contagious pathogen. We characterized a mechanism by which measles virus spreads rapidly through the cells that line the human airway in an <i>ex vivo</i> model. We show that the proteins of the viral membrane fusion apparatus, hemagglutinin (H) and fusion (F), move independently from and reach newly infected cells <i>before</i> the proteins of the replicative complex. Thus, viral protein spread is assembled and arranged in order (i.e., <i>marshaled</i>). Using adenovirus-based vectors, we show that co-expression of H and F proteins promotes rapid sequential spread to multiple cells and the formation of infectious centers. Further elucidation of the mechanism of measles virus amplification and cell-to-cell spread within the lung may help explain its highly contagious nature.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":" ","pages":"e0229726"},"PeriodicalIF":4.1,"publicationDate":"2026-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149182053","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"<i>bla</i>_IMP-4-associated imipenem susceptibility discordance in the <i>Klebsiella pneumoniae</i> complex: characterization and a phenotype-guided confirmatory workflow.","authors":"Haoyun Lin, Danxuan Lin, Yanchen Li, Zihan Zhao, Jingsong Wu, Tingting Xu, Jiayu Wu, Jine Cheng, Xiaopeng Yuan","doi":"10.1128/spectrum.01493-26","DOIUrl":"https://doi.org/10.1128/spectrum.01493-26","url":null,"abstract":"&lt;p&gt;&lt;p&gt;Automated antimicrobial susceptibility testing (AST) may generate carbapenem minimum inhibitory concentration (MIC) results differing from reference methods, complicating recognition of carbapenemase-producing &lt;i&gt;Klebsiella pneumoniae&lt;/i&gt; complex isolates. We characterized carbapenem susceptibility discordance in a retrospective discovery cohort of 133 carbapenemase-producing isolates collected in Shenzhen (2004-2017) by comparing imipenem (IPM) and meropenem (MEM) MICs obtained by VITEK 2 and broth microdilution (BMD). Confirmed discordance was defined as repeat-confirmed raw MIC differences of ≥2 log&lt;sub&gt;2&lt;/sub&gt; dilutions. Features were assessed by whole-genome sequencing, mCIM/eCIM, and exploratory phenotypic assays. Cross-card reproducibility was assessed using an alternative VITEK 2 AST card. A separate retrospectively enriched cohort of 166 &lt;i&gt;K. pneumoniae&lt;/i&gt; isolates (2018-2024) was used to evaluate a phenotype-guided reflex-testing workflow. Twenty-nine isolates showed confirmed carbapenem AST discordance, including 28 with IPM discordance. Of these, 27 had raw VITEK 2 IPM MICs at least 2 log₂ dilutions higher than those obtained by BMD, whereas one was reported as resistant after system adjustment despite a low raw MIC. All discrepant isolates carried &lt;i&gt;bla&lt;/i&gt;&lt;sub&gt;IMP-4&lt;/sub&gt; as the sole detected carbapenemase gene, had relatively low carbapenem MICs by BMD, and were distributed across 14 sequence types. Cross-card retesting reproduced the direction of IPM elevation, although the magnitude varied. In a combined internal analysis set of 275 isolates, the phenotype-guided workflow identified unflagged ≥2 log₂ MIC discrepancies with 81.4% sensitivity (95% CI, 67.4%-90.3%) and 92.2% specificity (95% CI, 88.1%-95.0%). These findings define a repeat-confirmed &lt;i&gt;bla&lt;/i&gt;&lt;sub&gt;IMP-4&lt;/sub&gt;-associated, IPM-predominant discordance between VITEK 2 and BMD and support phenotype-guided reflex-testing to identify unflagged MIC discrepancies and prioritize confirmatory testing in routine laboratories.IMPORTANCEClinical microbiology laboratories rely on automated systems to support antimicrobial susceptibility interpretation, but these systems may not always recognize method-dependent carbapenem susceptibility discordance. In this study, we show that a specific group of bacteria carrying the &lt;i&gt;bla&lt;/i&gt;&lt;sub&gt;IMP-4&lt;/sub&gt; gene can produce potentially misleading carbapenem susceptibility results, particularly for imipenem, when tested by automated methods. These discrepancies may not be flagged by the instrument and could therefore be overlooked in routine practice. By combining routine laboratory data with genetic analysis and additional testing, we identify a recognizable pattern associated with these hidden discrepancies and examine a phenotype-guided confirmatory workflow to support their laboratory recognition. Our findings highlight the importance of targeted confirmatory testing and provide a framework for local validation of laboratory-action","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":" ","pages":"e0149326"},"PeriodicalIF":4.1,"publicationDate":"2026-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149183265","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Metaproteomic analysis of human sonicate fluid highlights neutrophil extracellular trap formation associated with periprosthetic joint infection.","authors":"Elijah Garcia, Kathleen O'Connor, Christina Koscianski, Judith Alvarez Otero, Keara O'Donnell, Kiran K Mangalaparthi, Nicholas B Larson, Akhilesh Pandey, David Holmes, Robin Patel","doi":"10.1128/spectrum.00665-26","DOIUrl":"https://doi.org/10.1128/spectrum.00665-26","url":null,"abstract":"<p><p>Periprosthetic joint infection (PJI) is a devastating complication of total joint arthroplasty that can be challenging to diagnose and treat. Neutrophils are a prominent feature in PJI, with neutrophil extracellular traps (NETs) known to be present; little is known, however, about the physiology of PJI-associated NETs. Here, the proteomes of PJI and non-infectious arthroplasty failure (NIAF), analyzed using liquid chromatography tandem mass-spectrometry (LC-MS/MS) and proximity extension assay (PEA)-based profiling of fluids derived from sonication of arthroplasty components removed from patients who had undergone revision arthroplasty, were compared, with a focus on NET formation. In addition, <i>in vitro</i> effects of synovial fluid components on <i>Staphylococcus aureus-</i>induced NET formation were characterized. LC-MS/MS (PJI <i>n</i> = 85, NIAF <i>n</i> = 26) and PEA (PJI <i>n</i> = 95, NIAF <i>n</i> = 39) showed NET formation and neutrophil degranulation to be associated with PJI, with the complement cascade and platelet activation pathways identified as potential contributors. <i>In vitro</i> studies showed delayed NET formation in artificial synovial fluid compared to standard cell culture media conventionally used to evaluate NETs. Together, these results demonstrate the presence of NETs in PJI, identify potential pathways involved in PJI-associated NETosis, and point to an influence of synovial components on NET formation during PJI.</p><p><strong>Importance: </strong>Periprosthetic joint infection (PJI) is a major complication of joint replacement, placing a significant burden on patients and the healthcare system. Our research reveals that neutrophils and their antimicrobial \"traps\" are dominant features of the immune response at the infection joint site. Importantly, we found that the unique environment of the joint delays the formation of these traps, potentially contributing to the pathogenesis of PJI. By establishing a new experimental platform tailored for the infected joint, this work provides a foundational platform for probing these mechanisms and supports the development of improved diagnostic and therapeutic strategies.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":" ","pages":"e0066526"},"PeriodicalIF":4.1,"publicationDate":"2026-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149182735","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pentosan polysulfate sodium limits pulmonary inflammation in a SARS-CoV-2 mouse model.","authors":"Matt D Johansen, Stefan Miemczyk, Duc H Nguyen, Guanshu Zhao, Catherine J M Stapledon, Ravi Krishnan, Philip M Hansbro","doi":"10.1128/spectrum.01990-26","DOIUrl":"https://doi.org/10.1128/spectrum.01990-26","url":null,"abstract":"&lt;p&gt;&lt;p&gt;Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection remains prevalent globally, causing severe pulmonary inflammation and mortality in up to 10% of patients. While the introduction of effective vaccines has substantially reduced the number of severe coronavirus disease 2019 (COVID-19) cases, there are currently few available therapeutics that have been developed. Pentosan polysulfate sodium (PPS) has been shown to possess potent anti-inflammatory activity in influenza infection and allergen-induced rhinitis models and was recently demonstrated to inhibit SARS-CoV-2 infection &lt;i&gt;in vitro&lt;/i&gt;. As such, we hypothesized that PPS may represent an attractive therapeutic that could be utilized for SARS-CoV-2 infection and COVID-19. Using the K18-hACE2 mouse model of SARS-CoV-2 infection, we administered PPS (6 mg/kg) from either 1 (early) or 3 (late) days post-infection via intranasal instillation and then examined the efficacy in mitigating viral-induced inflammation and severe disease outcomes. We found that the early administration of PPS was accompanied by significant improvements in weight loss, clinical disease presentation, and neutrophilic airway inflammation. Early PPS administration also significantly reduced pro-inflammatory cytokine production at both the mRNA and protein levels while having no impact on viral titers or interferon and antiviral gene expression. Histologically, early treatment significantly prevented severe pulmonary inflammation and tissue remodeling. Comparatively, late administration of PPS worsened weight loss and clinical disease presentation following SARS-CoV-2 infection. Moreover, late administration was unable to prevent significant increases in pro-inflammatory cytokines and was further associated with significantly downregulated antiviral-associated genes. Histological examination also showed no protection in the late PPS administered groups. Taken together, these findings underscore the significance of time-dependent administration and demonstrate the therapeutic potential of PPS for treatment of SARS-CoV-2-induced inflammation.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Importance: &lt;/strong&gt;Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to cause infections globally, with most cases resulting in mild to moderate disease outcomes. However, approximately 10% of patients experience virally induced hyperinflammation leading to poor outcomes. As such, new or repurposed therapeutics need to be rapidly implemented to address this urgent medical need. Here, we show that pentosan polysulfate sodium (PPS) is a leading Food and Drug Administration (FDA)-approved therapeutic that significantly mitigates SARS-CoV-2-induced pulmonary inflammation. Critically, timing of PPS during the infection establishment and progression is critical for PPS efficacy, highlighting time-dependent responses that must be considered for further human clinical implementation. The findings from this study demonstrate that PPS hol","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":" ","pages":"e0199026"},"PeriodicalIF":4.1,"publicationDate":"2026-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149182926","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Isolation, identification, and pathogenicity comparison of three NADC30-like PRRSV variants with distinct mutational patterns.","authors":"Lei Zhao, Ying Guan, Yang-Ming Dai, Yi-Xin Yan, Shu-Ying He, Tong Xu, Li-Na Shao, Wu Xin, Si-Yuan Lai, Zhi-Wen Xu, Ling Zhu","doi":"10.1128/spectrum.01220-26","DOIUrl":"https://doi.org/10.1128/spectrum.01220-26","url":null,"abstract":"<p><p>Porcine reproductive and respiratory syndrome virus (PRRSV) remains a major challenge to disease control in the swine industry. Since NADC30-like PRRSV was first detected in China in 2013, it has become a particular concern because of its widespread circulation, frequent recombination, and variable pathogenicity. Here, three PRRSV isolates, SCABTC-202503, SCABTC-202505, and SCABTC-202506, were isolated and characterized. Whole-genome sequencing and phylogenetic analyses placed all three isolates within the NADC30-like L1C sublineage and identified characteristic discontinuous amino acid deletions in Nsp2. Recombination analyses indicated a shared NADC30-like genomic backbone, but distinct putative recombination patterns. Comparative GP5 analysis showed that SCABTC-202503 and SCABTC-202505 each harbored a single-amino-acid deletion at position 37 and multiple additional substitutions, whereas SCABTC-202506 encoded a full-length GP5 protein. In piglet challenge experiments, the three isolates showed different patterns of disease-associated changes, with variation in clinical scores, viral loads, cytokine levels, and the extent of lung lesions among the infected groups. However, because the isolates differed at multiple genomic sites, the association between the GP5 deletion and the observed phenotypic variation remains correlative. Establishing the specific contribution of the GP5 deletion will require infectious clone-based mutagenesis in a controlled genetic background. Collectively, these findings highlight the genetic and phenotypic heterogeneity of the NADC30-like PRRSV isolates examined and underscore the importance of continued surveillance of emerging variants.IMPORTANCEPorcine reproductive and respiratory syndrome virus (PRRSV) remains a major pathogen affecting the swine industry because of its rapid evolution, frequent recombination, and variable pathogenicity. NADC30-like PRRSV has circulated widely in China and continues to diversify genetically. In this study, we obtained three recently circulating NADC30-like PRRSV isolates belonging to the L1C sublineage from clinical samples collected in China. We characterized their whole-genome sequences, phylogenetic relationships, putative recombination patterns, GP5 and Nsp2 sequence variations, and disease-associated changes in piglets. Under the conditions tested, the isolates exhibited genetic heterogeneity and varying degrees of clinical, virological, pathological, and inflammatory changes. These findings expand current knowledge of NADC30-like PRRSV diversity and underscore the importance of continued genomic surveillance for tracking emerging variants and informing future prevention and control strategies.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":" ","pages":"e0122026"},"PeriodicalIF":4.1,"publicationDate":"2026-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149182772","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}