Microbiology spectrum最新文献

{"title":"<i>Staphylococcus</i> biofilm dynamics and antibiotic resistance: insights into biofilm stages, zeta potential dynamics, and antibiotic susceptibility.","authors":"T Lavoie, K E Daffinee, M L Vicent, K L LaPlante","doi":"10.1128/spectrum.02915-24","DOIUrl":"https://doi.org/10.1128/spectrum.02915-24","url":null,"abstract":"&lt;p&gt;&lt;p&gt;&lt;i&gt;Staphylococcus&lt;/i&gt; spp. infections often involve biofilms, but standard antibiotic minimum inhibitory concentration (MIC) testing used to determine treatment evaluates planktonic bacterial growth only and does not account for biofilm presence, strength, or growth stage. To aid in determining a cost-effective method to solve this issue, we built upon &lt;i&gt;in vitro&lt;/i&gt; methods initially published by Stepanovic et al. used to determine weak and strong biofilm formations. First, we determined 115 unique &lt;i&gt;S. aureus&lt;/i&gt; isolate biofilms at 2, 4, 6, 8, 16, and 24 h to classify the hourly stages of biofilm development based on statistically significant final growth results (&lt;i&gt;P&lt;/i&gt; &lt; 0.001): stages one (0-6 h), two (6-16 h), three (16-24 h), and four (&lt;u&gt;&gt;&lt;/u&gt;24 h). Next, to further evaluate &lt;i&gt;in vitro&lt;/i&gt; biofilm strength, electrostatic differences were measured through zeta (ζ)-potential for strong and weak biofilm producers at early and late stage-formed biofilms. The early stages of weak biofilm formers had a greater negative electrostatic charge when compared to strong biofilm formers. Meanwhile, strong biofilm formers began early stages with less negative charges before increasing the negative electrostatic charge by stage-four biofilm. At all time points, weak biofilm-forming isolate mean ζ-potentials were significantly more negative than strong biofilm formers (&lt;i&gt;P&lt;/i&gt; = ≤0.04). Finally, to elucidate minimum eradication concentrations for biofilms, we treated stage-four biofilms with progressively higher concentrations of either daptomycin, vancomycin, or levofloxacin. Daptomycin was the only antibiotic to achieve ≥75% reduction in biofilm viability, seen at 32-256 μg/mL (64-512× MIC), and significantly reduced residual biofilm across all strong and weak biofilms. Biofilm findings showed an unexpected initial biofilm decrease in response to lower concentrations of antibiotics, followed by an increase in biofilm biomass at higher antibiotic concentrations. While higher antibiotic concentrations can be used to overcome bacterial resistance and eliminate infections, our results suggest that antimicrobial resistance is observed, regardless of bacterial biofilm strength, and that there may be an optimal treatment concentration window for achieving maximum kill. Our data add to the increasing evidence of biofilms' role in recurrent infections and the importance of antibiotic concentration.IMPORTANCEThis work is significant, as it addresses a critical gap in standard antibiotic testing by focusing on the unique characteristics of biofilm-forming &lt;i&gt;Staphylococcus aureus&lt;/i&gt; infections, which are major contributors to recurrent and chronic infections. Unlike traditional MIC testing that evaluates planktonic bacteria, this study emphasizes the importance of biofilm presence, growth stages, and electrostatic properties in determining treatment strategies. By classifying biofilm development into distinct stages in an easily reproducible assay an","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":" ","pages":"e0291524"},"PeriodicalIF":3.7,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143710850","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":"Application of rapid Nanopore metagenomic cell-free DNA sequencing to diagnose bloodstream infections: a prospective observational study.","authors":"Morten Eneberg Nielsen, Kirstine Kobberøe Søgaard, Søren Michael Karst, Anne Lund Krarup, Mads Albertsen, Hans Linde Nielsen","doi":"10.1128/spectrum.03295-24","DOIUrl":"https://doi.org/10.1128/spectrum.03295-24","url":null,"abstract":"<p><p>Bloodstream infections are a major cause of mortality, often leading to sepsis or septic shock. Rapid initiation of effective antimicrobial therapy is essential for survival; however, the current gold standard for identifying pathogens in bloodstream infections, blood culturing, has limitations with long turnaround time and poor sensitivity. This delay in refining empirical broad-spectrum antimicrobial treatments contributes to increased mortality and the development of antimicrobial resistance. In this study, we developed a metagenomic next-generation sequencing assay utilizing the Oxford Nanopore Technologies platform to sequence microbial cell-free DNA from blood plasma. We demonstrated proof of concept in a prospective observational clinical study including patients (<i>n</i> = 40) admitted to the emergency ward on suspicion of bloodstream infection. Study samples were drawn from the same venipuncture as a blood culture sample from the included patients. Nanopore metagenomic sequencing confirmed all microbiological findings in patients with positive blood cultures (<i>n</i> = 11) and identified pathogens relevant to the acute infection in an additional 11 patients with negative blood cultures. This proof-of-concept study demonstrates that culture-independent Nanopore metagenomic sequencing directly on blood plasma could be a feasible supplementary test for infection diagnostics in patients admitted with severe infections or sepsis. These findings support further studies on Nanopore metagenomic sequencing for sepsis diagnostics in larger cohorts to validate and expand the results from this study.IMPORTANCEThis study demonstrates the potential of Nanopore metagenomic sequencing as a rapid, culture-independent diagnostic tool for bloodstream infections, identifying pathogens missed by conventional blood cultures. The study highlights the method's promise in improving pathogen detection and warrants further validation in larger clinical studies.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":" ","pages":"e0329524"},"PeriodicalIF":3.7,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143710853","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":"Identification of novel <i>amrR</i> deletions as meropenem resistance mechanisms in clinical <i>Burkholderia pseudomallei</i> isolates.","authors":"Supichaya Nimnuan-Ngam, Shirley Yi Fen Hii, Rathanin Seng, Natnaree Saiprom, Sarunporn Tandhavanant, T Eoin West, Narisara Chantratita","doi":"10.1128/spectrum.01936-24","DOIUrl":"https://doi.org/10.1128/spectrum.01936-24","url":null,"abstract":"<p><p><i>Burkholderia pseudomallei,</i> an environmental bacterium, is the causative agent of melioidosis, a potentially fatal infectious disease predominantly found in tropical regions. Despite the bacterium's intrinsic resistance to numerous antibiotics, the antibiotic resistance mechanisms remain poorly understood. Recently, we identified novel partial deletions in the <i>amrR</i> gene of meropenem less-susceptible (MEM-LS) isolates (DR10212A, DR90049A, and DR90031E) obtained from patients with melioidosis. In this study, we performed mutagenesis and quantitative reverse-transcription real-time polymerase chain reaction (RT-qPCR) to validate the roles of these partial deletions in the <i>amrR</i> gene in MEM-LS isolates. By introducing wild-type <i>amrR</i> fragments from strain K96243 into three parental MEM-LS isolates, we successfully constructed three complemented mutant strains (DR10212A∷K96243-<i>amrR</i>, DR90049A∷K96243-<i>amrR</i>, and DR90031E∷K96243-<i>amrR</i>), which exhibited significantly decreased MEM minimum inhibitory concentrations (MIC) compared with their parental strains. Consistent with the decreased MIC, the expression levels of AmrAB-OprA efflux pump genes (<i>oprA</i>, <i>amrB</i>, and <i>amrA</i>) in the complemented mutant strains were downregulated at least 5-fold compared with the parental isolates, indicating the significant role of the partial <i>amrR</i> gene deletions in MEM-LS. Our findings provide more understanding of the MEM resistance mechanisms of clinical isolates of <i>B. pseudomallei</i>, thereby enhancing future strategies for the treatment and management of melioidosis.IMPORTANCEAntibiotic resistance of <i>B. pseudomallei</i> poses a significant threat to patients with melioidosis because it interferes with the recovery process and is associated with high mortality. This study reported that three new mutations involving efflux pumps in <i>amrR</i> (H92_S154del, V197del, and A202_R207del) confer resistance to MEM. These mutations were previously detected using whole genome sequencing (WGS) analysis of MEM-LS isolates from melioidosis patients in northeast Thailand. The data from this study provide more understanding of common mechanisms of drug resistance in <i>B. pseudomallei</i>. This information is essential for the development of more effective drugs for melioidosis treatment in the future.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":" ","pages":"e0193624"},"PeriodicalIF":3.7,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143710008","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":"Post-pandemic upsurge in Group A <i>Streptococcus</i> infections at an Italian tertiary university hospital.","authors":"Gabriele Arcari, Federica Novazzi, Lorenzo Colombini, Francesca Drago Ferrante, Sara Boutahar, Angelo Paolo Genoni, Gianluca Cassani, Paolo Gigante, Mattia Carbotti, Alessandro Bianco, Mariana Tirziu, Riccardo Capuano, Renee Pasciuta, Francesco Iannelli, Nicola Clementi, Francesco Santoro, Nicasio Mancini","doi":"10.1128/spectrum.02494-24","DOIUrl":"https://doi.org/10.1128/spectrum.02494-24","url":null,"abstract":"<p><p><i>Streptococcus pyogenes</i> (Group A <i>Streptococcus</i>; GAS) is a pathogen of global significance. In the pre-antibiotic era, GAS was a major cause of childhood morbidity and mortality, but its spread rapidly declined until the mid-2010s. The continuing increase in GAS infections, associated with the expansion of the M1_UK lineage, was observed first in the United Kingdom (UK) and, later, globally. Here, we endeavor to assess the various determinants underlying the post-pandemic GAS upsurge, with a focus on microbial genomic features. We performed an epidemiological analysis of all laboratory-confirmed GAS infections identified between June 2018 and June 2024 at a tertiary University Hospital located in Northern Italy, dividing them into three levels of severity: mild, moderate, and invasive GAS infections. A subset of 34 representative GAS isolates identified in the post-pandemic period were subjected to short- and long-read whole genome sequencing (WGS). Of the 531 GAS cases analyzed during this period, the majority (415, 78.2%) occurred in the last two years. This increase in GAS cases correlated with a significant shift in infection severity: among the 118 GAS cases identified in the June 2018-May 2022 period, only one resulted in an invasive infection (1/118, 0.8%). In contrast, among the 531 GAS cases identified in the June 2022-May 2024 period, 32 caused invasive infections (32/531, 7.9%). WGS of 34 isolates (including 15 invasive isolates) identified 11 different <i>emm</i> types, the most frequent being <i>emm</i>1 (9 isolates) followed by <i>emm</i>12 (7 isolates), then <i>emm</i>89 and <i>emm</i>28 (4 isolates each). Among the <i>emm</i>1 isolates, the M1_UK sublineage was the most represented (8 out of 9 isolates), with the remaining \"singleton\" belonging to the M1_13SNP sublineage.</p><p><strong>Importance: </strong><i>Streptococcus pyogenes</i> (GAS) is a narrow-spectrum pathogen, circulating only in humans. Following the loosening of various public health measures implemented to face the challenge of the COVID-19 pandemic, a significant rise in GAS cases has been observed. Our study revealed a significant rise in GAS cases, particularly invasive infections, over the last two years. Genomic analysis identified multiple sequence types, including isolates belonging to an emerging lineage named M1_UK. These findings underscore the importance of ongoing surveillance and genomic monitoring of GAS infections, especially considering their rising incidence and severity. Public health strategies should consider not only microbe-associated aspects but also host-associated and external factors to effectively address this resurgence and prevent future outbreaks.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":" ","pages":"e0249424"},"PeriodicalIF":3.7,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143709935","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":"Genome-wide identification of long non-coding RNAs reveals potential association with <i>Phytophthora infestans</i> asexual and sexual development.","authors":"Weilin Cao, Xiangming Pan, Ru Yu, Yuting Sheng, Hongxia Zhang","doi":"10.1128/spectrum.01998-24","DOIUrl":"https://doi.org/10.1128/spectrum.01998-24","url":null,"abstract":"<p><p>Long non-coding RNAs (lncRNAs) play pivotal roles in regulating diverse biological processes across plants, mammals, and fungi. However, the information on lncRNAs in oomycete asexual and sexual reproduction, which are two pivotal processes in the pathogenic cycle, has not been elucidated. In this present study, strand-specific RNA sequencing data of <i>Phytophthora infestans</i> with asexual development and sexual reproduction were reanalyzed, and a total of 4,399 lncRNAs were systematically identified. Compared to messenger RNAs (mRNAs), lncRNAs had a higher proportion of transcripts containing more than one exon, shorter nucleotide lengths, and lower expression levels. Target analysis showed that although only 280 lncRNA-mRNA pairs were shared, the functional pathways in which <i>cis</i> and <i>trans</i> targets participated were similar. Weighted gene co-expression network analysis of differentially expressed lncRNAs (DElncRs) and differentially expressed mRNAs (DEmRs) of asexual development stages indicated that lncRNAs might participate in different asexual stages and transformation of the growth stages via regulating functional genes. Expression trend analysis of DElncRs and DEmRs showed that lncRNAs may promote asexual development via upregulating mRNAs encoding development- and invasion-related proteins, such as INF6, triosephosphate isomerase, and glycoprotein elicitor. Co-expression analysis of DElncRs and DEmRs of sexual reproduction showed that lncRNAs could increase the level of mRNAs related to mating, such as M96 mating-specific protein and Crinkler family protein, which meant that lncRNAs might participate in sexual reproduction by regulating mating-related genes. Our study conducted a comprehensive analysis of lncRNAs in <i>P. infestans</i> and suggested a potential function of lncRNAs in asexual and sexual development.</p><p><strong>Importance: </strong>This study systematically analyzed lncRNAs in <i>Phytophthora infestans</i>, revealing the associations between lncRNAs and functional genes. The potential regulatory roles of lncRNAs in the asexual and sexual reproduction stages were clarified, providing a new perspective for in-depth understanding of the reproductive regulatory network of oomycetes. This not only expands the understanding of the functions of non-coding RNAs in different biological groups but also provides potential targets for the development of new disease prevention and control strategies, promoting related research in the fields of agriculture and biology.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":" ","pages":"e0199824"},"PeriodicalIF":3.7,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143710858","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":"Reducing tuberculosis transmission by genotype-based contact tracing coupled with public health containment measures: a case study during the COVID-19 pandemic in Taiwan.","authors":"Yuan-Shan Chien, Chao-Chih Lai, Chen-Yang Hsu, Yu-Chu Hsieh, Shin-Yi Lin, Hsiao Chi Wang, Hung-Pin Chen, Tony Hsiu-His Chen, Dih-Ling Luh, Yen-Po Yeh","doi":"10.1128/spectrum.02125-24","DOIUrl":"https://doi.org/10.1128/spectrum.02125-24","url":null,"abstract":"<p><p>This study aimed to estimate the effectiveness of genotype-based contact tracing coupled with public health and social containment measures (PHSMs) in reducing tuberculosis (TB) transmission during the COVID-19 pandemic. Patients suspicious of recent TB infection from index cases were traced by genotyping method between 2017 and 2021. To make allowance for TB cases attributed to reactivation, TB cases identified from the genotype-based contact tracing group were compared to those from the underlying population via the notifiable nationwide system without genotyping. The relative changes (ratios) in TB cases before and during the pandemic between the two groups were leveraged to estimate the effectiveness of PHSMs following genotype-based contact tracing, taking into account demographic features and geographic variation, with a multivariable Poisson regression model. Before the pandemic, we identified 42 of 133 (31.6%) sputum culture-positive index (SCI) patients via 344 genotype-matched clustered TB cases. During the pandemic, 11 of 70 (15.7%) SCI patients were linked to 36 clustered cases. The annual average of TB-clustered patients for the genotype-based contact tracing group decreased by 84.3%, whereas the corresponding figure for the comparator decreased by 18.5%. The adjusted relative risk of 0.19 (95% CI 0.14-0.28) gave an 81% TB transmission reduction after controlling for extraneous factors. Genotype-based contact tracing coupled with PHSMs significantly reduced TB transmission. Our findings from the pandemic period demonstrate that a molecular epidemiological approach with public health containment measures will enable a moderate-burden TB country to reach the WHO End TB targets by 2035.IMPORTANCEThe extent to which COVID-19 public health and social measures reduced tuberculosis transmission remains unclear. We elucidated the recent tuberculosis infection with a novel genotype-based contact tracing from 2017 to 2021. These patients were recruited as the contact tracing group in contrast to the comparison group of tuberculosis cases from the general population via the notifiable nationwide system without genotyping. The relative changes in tuberculosis cases before and during the pandemic between the contact tracing group and the comparison group were used to estimate the effectiveness of reducing tuberculosis transmission. We found a significant 81% reduction in tuberculosis transmission during the first 2 years of the pandemic. This finding demonstrates that a molecular epidemiological approach with public health containment measures will enable a moderate-burden tuberculosis country to reach the End TB targets by 2035.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":" ","pages":"e0212524"},"PeriodicalIF":3.7,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143710207","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":"Identification of <i>Toxoplasma gondii</i> antigenic proteins using an <i>in vivo</i> approach and <i>in silico</i> investigation of their polymorphism.","authors":"J Denis, C Gommenginger, L Beal, B Cimon, A S Deleplancque, H Fricker Hidalgo, C L'Ollivier, L Paris, H Pelloux, C Pomares, S Houze, A W Pfaff, I Villena, O Villard","doi":"10.1128/spectrum.02040-24","DOIUrl":"https://doi.org/10.1128/spectrum.02040-24","url":null,"abstract":"<p><p><i>Toxoplasma gondii</i> is a pathogen characterized by a large variety of strains whose virulence and clinical severity are likely linked to their genotype. Currently, the strains are genotyped using restriction fragment length polymorphism, multilocus sequence typing, and microsatellite markers. This typing requires the strain's DNA, which is difficult to obtain. A serotyping test could overcome the constraints of genotyping, the challenge being to identify type-specific proteins. We identified immunogenic <i>T. gondii</i> proteins from co-immunoprecipitations for three tachyzoite strains (strain FOU from Africa 1 type, ME49 from Type II, and VEG from Type III) with hyperimmune murine sera and conducted an <i>in silico</i> polymorphism search for the identified proteins. A variant calling analysis was conducted on the next-generation sequencing sequences of 117 <i>T. gondii</i> isolates with the objective of identifying mutations present in the genes encoding the antigenic proteins previously identified. A total of 727 immunogenic proteins were identified, including 16% dense granule protein (GRA), rhoptry protein (ROP/RON), and surface antigen protein (SAG). Genetic analysis revealed the presence of 36 single-nucleotide polymorphisms (SNPs) in over 70% of isolates belonging to the same type, while less than 30% of isolates belonging to the other types exhibited these polymorphisms. Of these, only 15 are located on coding DNA sequence regions, while four are located on genes encoding apicomplexan proteins: two SNPs on the ROP5 gene and two on the ROP7 gene. The results of this study indicate that a significant number of <i>T. gondii</i> immunogenic proteins can be identified using an <i>in vivo</i> approach. The <i>in silico</i> study identified SNPs that could be genotype-specific.</p><p><strong>Importance: </strong><i>Toxoplasma gondii</i> is a unique species that exhibits genotype diversity related to clinical virulence. Currently, genotyping is restricted, which limits epidemiological knowledge of the strains. To overcome this limitation, we aimed to develop serotyping tests. First, we used a murine <i>in vivo</i>, non-targeted experimental approach based on proteomics techniques through which we were able to identify a panel of more than 700 antigenic proteins from <i>T. gondii</i>. Then, we analyzed the polymorphism of these proteins using a whole-genome sequencing database containing the genomes of 117 genotyped strains. We showed that none of the 986 non-silent SNPs detected is specific to the strain type. The <i>in vivo</i> approach is the first that allowed the identification of such a large panel of antigenic proteins. Moreover, the polymorphism analysis, the first based on a large next-generation sequencing database, showed the limits that currently restrict the development of a serotyping technique.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":" ","pages":"e0204024"},"PeriodicalIF":3.7,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143710860","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":"The microvascular endothelium of the blood-brain barrier is highly restrictive to JC Polyomavirus neuroinvasion.","authors":"Avraham S Lukacher, Bethany A O'Hara, Wenqing Yuan, Kaitlin Garabian, Jacob Kaiserman, Evan MacLure, Sheila A Haley, Walter J Atwood","doi":"10.1128/spectrum.00282-25","DOIUrl":"https://doi.org/10.1128/spectrum.00282-25","url":null,"abstract":"<p><p>JC Polyomavirus is the causative agent of progressive multifocal leukoencephalopathy (PML), an often-fatal demyelinating disease. Unfortunately, a diagnosis of PML occurs only after patients have suffered irreversible neuropathologies. The first step in the initiation of PML is viral entry to the brain, but the route and mechanisms responsible for neuroinvasion have not been well established. To gain a better understanding of this, we asked whether purified virus or virus associated with extracellular vesicles (EVs) could penetrate two different cell culture models of the blood-brain barrier. In one model, we used the hCMEC/D3 brain endothelial cell line, and in the other, we used pluripotent stem cells induced to a brain endothelial cell phenotype (iPSC-EC). We found that neither cell type was permissive to viral infection, but the virus bound and was internalized by both in a sialic acid-dependent manner. Despite virus internalization into these cells, very few virions or virus-associated extracellular vesicles (virus-EVs) penetrated the barriers. The small amount of virus or virus-EVs that did pass through either barrier was sufficient to establish infection in human glial cells. Our findings demonstrate that limited amounts of infectious virions and virus-associated EVs can traverse the brain microvascular endothelium and establish infection.IMPORTANCEThe human polyomavirus, JC Polyomavirus (JCPyV), causes a rapidly progressing demyelinating disease in immunocompromised or immunomodulated patients. Demyelinating lesions are often seen surrounding blood vessels in the brain. In this paper, we used two models to recapitulate a minimal blood-brain barrier and found that both were highly restrictive of virus penetration. A small amount of virus succeeded in crossing both barriers and was sufficient to establish infection of human glia. These data have direct implications for mechanisms used by JCPyV to invade the CNS and cause neurological disease.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":" ","pages":"e0028225"},"PeriodicalIF":3.7,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143701005","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":"Gene dosage of <i>PDR16</i> modulates azole susceptibility in <i>Candida auris</i>.","authors":"Trinh Phan-Canh, Tamires Bitencourt, Karl Kuchler","doi":"10.1128/spectrum.02659-24","DOIUrl":"https://doi.org/10.1128/spectrum.02659-24","url":null,"abstract":"","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":" ","pages":"e0265924"},"PeriodicalIF":3.7,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143700723","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":"Application value of nucleic acid MALDI-TOF MS in mycobacterial species identification and drug resistance detection in <i>Mycobacterium tuberculosis</i>.","authors":"Xiaofang Liu, Honghong Niu, Donglin Guo, Huixia Gao, Lihong Wu, Jingyang Liu, Chunfeng Bai, Yuxi Li, Peilong Wang, Zhengfeng Zhou, Yuling Wang, Jianqin Liang, Wenping Gong","doi":"10.1128/spectrum.01545-24","DOIUrl":"https://doi.org/10.1128/spectrum.01545-24","url":null,"abstract":"<p><p>Tuberculosis (TB) and non-tuberculous mycobacteria (NTM) infections pose global health threats, requiring swift and accurate identification for effective treatment. This study aims to assess the ability of nucleic acid matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) to rapidly identify <i>Mycobacterium tuberculosis</i> (MTB), NTM, and the drug resistance of MTB. A comparative analysis of 133 clinical samples was performed using acid-fast bacilli (AFB) staining, Lowenstein-Jensen (LJ) culture, GeneXpert, real-time PCR, and nucleic acid MALDI-TOF MS. The study focused on the diagnostic performance of nucleic acid MALDI-TOF MS in detecting MTB and NTM, as well as its accuracy in identifying the drug resistance profiles of MTB. The positive detection rate of nucleic acid MALDI-TOF MS for mycobacterium was 84.96%, which was significantly higher than that of AFB staining (29.32%). For NTM, nucleic acid MALDI-TOF MS had 89.29% sensitivity and 97.14% specificity, with an area under the curve (AUC) of 0.932, which was superior to other methods. The nucleic acid MALDI-TOF MS identified 28 NTM species, while real-time PCR identified only 12. Drug resistance detection showed concordance rates of 80% to 95% compared with drug sensitivity tests of LJ culture. Nucleic acid MALDI-TOF identified mutations, like KatG315 AGC-ACC for low-level isoniazid resistance, rpoB 531 TCG-TTG for high-level rifampicin resistance, and the InhA-15 C-T mutations, were also found in six isoniazid resistance cases and prothionamide resistance cases. Nucleic acid MALDI-TOF MS is a valuable diagnostic tool for the rapid and precise identification of mycobacterial species and the drug resistance profiles of MTB. With high sensitivity and specificity, it can guide the early initiation of effective anti-tuberculosis treatment in clinical settings.IMPORTANCETuberculosis (TB) remains a critical global health challenge, exacerbated by the emergence of drug-resistant strains. Accurate, rapid diagnosis is imperative for effective treatment and control of TB. The ability to discern MTB from NTM is equally vital, as they demand distinct therapeutic approaches. This study underscores the significance of nucleic acid matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) technology in providing a swift and precise diagnostic tool. Its high sensitivity and specificity in identifying mycobacterial species and their resistance profiles are paramount for guiding targeted anti-tuberculosis therapy. By potentially reducing the time to diagnosis and enabling personalized treatment plans, this technology could revolutionize TB management, ultimately mitigating its impact on public health.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":" ","pages":"e0154524"},"PeriodicalIF":3.7,"publicationDate":"2025-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143710855","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}