Microbiology spectrum最新文献

{"title":"Niclosamide nanoparticles as a novel adjuvant reverse colistin resistance via multiple mechanisms against multidrug-resistant <i>Salmonella</i> infections.","authors":"Kaifang Yi, Peiyi Liu, Mengyao Zhang, Qiange Liu, Mengjing Feng, Zibo Li, Dandan He, Li Yuan, Xiaoyuan Ma, Gongzheng Hu","doi":"10.1128/spectrum.02252-25","DOIUrl":"https://doi.org/10.1128/spectrum.02252-25","url":null,"abstract":"<p><p>The mobile colistin resistance (<i>mcr</i>) mechanism enables rapid horizontal transfer of resistance genes across food, animals, and humans, driving significant resistance in <i>mcr</i>-carrying bacteria. While numerous adjuvants can reverse colistin resistance, research on their dose-response relationships remains limited, and most suffer from poor solubility, low bioavailability, and safety issues, hindering clinical use. The dose-response analysis showed that niclosamide could achieve a high reversal efficiency within a relatively low concentration range. However, as the concentration of niclosamide increased, the ability to reverse colistin resistance remained unchanged, and the reversal efficiency gradually decreased. Mechanistic analyses reveal that its synergistic antibacterial effect with colistin involves disrupting bacterial membrane permeability, dissipating proton motive force, and inhibiting efflux pumps, leading to membrane damage, cytoplasmic leakage, ATP depletion, and accelerated reactive oxygen species-mediated oxidative damage, ultimately resulting in the death of bacterial cells. A niclosamide nanodelivery system (niclosamide-loaded mPEG-PLGA nanoparticles [NCL@mPEG-PLGA-NPs]) was developed to enhance bioavailability, significantly boosting colistin's efficacy against <i>Salmonella in vitro</i> and <i>in vivo</i>. The in-depth study of the dose-response relationship of adjuvants in reversing colistin resistance and the establishment of the niclosamide nanodrug delivery system will lay a scientific foundation for the clinical application of colistin adjuvants and the development of suitable drug delivery systems.</p><p><strong>Importance: </strong>Colistin is used as a last resort for many infections caused by multidrug-resistant gram-negative bacteria, but colistin-resistant strains are on the rise. Studies have found that the combination of niclosamide and colistin exhibits significant synergistic antibacterial effects. Dose-response analysis shows that niclosamide has extremely high resistance reversal efficiency within a relatively low concentration range. The development of the new dosage form of NCL@mPEG-PLGA-NPs will lay a scientific foundation for the clinical application of colistin adjuvants and the development of drug delivery systems.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":" ","pages":"e0225225"},"PeriodicalIF":3.8,"publicationDate":"2025-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145329296","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":"Seasonal dynamics and environmental controls of planktonic archaea in a typical subtropical estuary.","authors":"Wenya Wei, Penghui Li, Fahui Gong, Cheng Zhang, Kedong Yin, Wei Xie","doi":"10.1128/spectrum.00759-25","DOIUrl":"https://doi.org/10.1128/spectrum.00759-25","url":null,"abstract":"<p><p>Planktonic archaea are pivotal in the biogeochemical cycling across estuaries to coastal seas. A thorough comprehension of their adaptive mechanisms to seasonal environmental fluctuations remains largely unexplored. This study investigates the seasonal dynamics of planktonic archaeal communities and their responses to the biotic and abiotic factors in the Pearl River Estuary (PRE). Thermoproteota and Thermoplasmatota are the two most abundant phyla, and both show a significant difference between summer and winter. As phosphorus is the most limiting nutrient in the PRE, PO₄^3- is found to have the most significant seasonal variation in random forest, followed by temperature and Chl a. The Mantel test for the abundant archaea showed that the number of phosphate-correlated OTUs was the second highest, following only temperature. The generalized additive modeling (GAM) analysis further reveals that the abundance of Thermoproteota was controlled by PO₄^3-, temperature, and DO, whereas MGII was controlled by PO₄^3-, pH, salinity, and Chl a. Our research demonstrates that there is a strong seasonality in coastal archaeal communities and sheds light on revealing their environmental adaptation and predicting biogeochemical function alterations in response to regional and global environmental changes.</p><p><strong>Importance: </strong>Archaea not only sustain the equilibrium of elemental cycles but also exhibit remarkable plasticity in responding to and adapting to fluctuating environmental conditions. In particular, the adaptive strategies and ecological impacts of archaea in complex and dynamic settings, such as estuaries, represent a compelling yet unresolved area of scientific inquiry. Our study focused on the seasonal dynamics of planktonic archaeal communities in the Pearl River Estuary (PRE) and their response to biotic and abiotic factors. Our study demonstrates a strong seasonality in the aggregation of these coastal archaeal communities and adaptability to dynamic phosphate concentrations, emphasizing the critical role of phosphate in controlling the distribution of archaea. Our study sheds light on revealing environmental adaptation and predicting biogeochemical function alterations in response to regional and global environmental changes.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":" ","pages":"e0075925"},"PeriodicalIF":3.8,"publicationDate":"2025-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145329403","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":"Genomic insights and functional adaptation of <i>Mycobacterium intracellulare</i> strains isolated from patients with inflammatory bowel disease.","authors":"Sushanta Deb, Lata Kumari, Neeraj Mahajan, Shiv K Basant, Twinkle Joshi, Vineet Ahuja, Urvashi B Singh","doi":"10.1128/spectrum.03414-24","DOIUrl":"https://doi.org/10.1128/spectrum.03414-24","url":null,"abstract":"<p><p>In clinical practice, inappropriate diagnosis of inflammatory bowel disease (IBD) ascribing the disease to <i>Mycobacterium avium paratuberculosis</i> (MAP) and resulting mistreatment has been a challenge for healthcare workers. This highlights the need to accurately identify and characterize MAP members in patients with gastrointestinal (GI) ulceration. A total of 889 patients exhibiting symptoms of IBD were examined for MAP infection. While MAP was not recovered from any of the specimens, we successfully isolated and sequenced four clinically relevant <i>Mycobacterium intracellulare</i> genomes from GI samples of patients diagnosed with IBD. In-depth phylogenomic and comparative genomics demonstrated genomic heterogeneity and variable metabolic profile in <i>M. intracellulare</i> species. Analysis of four isolate genomes disclosed an ongoing genome reduction process, which might be crucial for adaptation and increased virulence of intestinal <i>M. intracellulare</i> strains. Findings provide insights into the narrow-spectrum resistance to antibiotics, metabolic adaptation, and potential virulence of <i>M. intracellulare</i> strains, particularly those associated with human infections. Recombination analysis revealed minimal recombination and higher mutational divergence, which indicate evolutionary constraints leading to clonal evolution of <i>M. intracellulare</i> species.</p><p><strong>Importance: </strong>The present study provides valuable insights on genomic diversity, metabolic adaptability, and virulence of <i>Mycobacterium intracellulare</i> strains infecting human host. Our findings highlight the need for additional research on essential genes as potential drug targets. An updated knowledge on intestinal <i>M. intracellulare</i> strains regarding its genomic characteristics and evolutionary processes is critical to design better diagnostic and treatment approaches for intestinal infections.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":" ","pages":"e0341424"},"PeriodicalIF":3.8,"publicationDate":"2025-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145329655","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":"Sublethal interaction factor (SIF), a growth-based method to analyze antibiotic combinations at sub-inhibitory concentrations.","authors":"D L Sánchez-Hevia, N Fatsis-Kavalopoulos, D I Andersson","doi":"10.1128/spectrum.01070-25","DOIUrl":"https://doi.org/10.1128/spectrum.01070-25","url":null,"abstract":"<p><p>Antibiotic resistance is a global concern with significant implications for healthcare, food production, and the environment. Therapies involving antibiotic combinations are frequently employed as a strategy to overcome antibiotic resistance. When present in combination, the efficacy of antibiotics may be enhanced or weakened, and as antibiotic interactions are <i>a priori</i> generally unpredictable, they need to be experimentally determined. Though antibiotics are regularly present at sublethal concentrations (e.g., in patients with suboptimal dosing regimens, late after the last dosage, difficult-to-penetrate tissues, and also in the natural environment), effects of antibiotic combinations are generally studied at lethal dosages. To address this, we developed the sublethal interaction factor (SIF) assay, based on the Bliss independence model, to quantify antibiotic combination effects at sublethal concentrations. SIF assay uses the whole growth curve, instead of only the growth rate, and determines reliably the outcome of the interaction between two antibiotics at sublethal concentrations. The SIF method was validated against the CombiANT assay and showed high sensitivity and specificity, attesting to its usability.IMPORTANCESublethal interaction factor (SIF), a method herein proposed, simplifies the analysis of antibiotic interactions at sub-inhibitory concentrations and shows a high correlation with the fractional inhibitory concentration index (FICi), the gold-standard measure used to classify antibiotic interactions when tested at lethal concentrations. The SIF can be easily incorporated into laboratories and has great potential for studying not only antibiotic combinations but also drug interactions and phage therapy.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":" ","pages":"e0107025"},"PeriodicalIF":3.8,"publicationDate":"2025-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145329527","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":"Mapping the respiratory microbiome in intubated children over time.","authors":"Keiko M Tarquinio, Jennifer Farrell, John J Varga, Conan Zhao, Elijah Mehlferber, Sam P Brown","doi":"10.1128/spectrum.00448-25","DOIUrl":"https://doi.org/10.1128/spectrum.00448-25","url":null,"abstract":"<p><p>Children who require airway intubation are almost always treated with empiric antibiotics, pending clinical microbiology results. Positive pathogen results are near inevitable, due to the frequent presence of potential opportunistic pathogens, whether they are causing disease or not. This pattern leads to potential antibiotic over-prescribing, to the detriment of both patients who do not require antibiotics and to antimicrobial stewardship goals. To assess our hypothesis that opportunistic pathogens are more common in children with prior lung disease, we prospectively profiled tracheal aspirate (TA) microbiome samples in children with and without prior lung disease. An IRB approval was obtained, and TAs were collected longitudinally. Samples were analyzed using 16S rDNA sequencing and conventional cultures. Patient demographics and clinical courses were obtained using electronic medical records. Thirteen subjects were included, producing 39 TA samples. Microbiome analysis identified 98 bacterial genera, dominated by <i>Pseudomonas</i> and <i>Streptococcus</i>. Patient identity was a significant determinant of TA sample variation, indicating a robust individual TA microbiome despite the presence of substantial antibiotic exposures. In contrast, clinical category and time since intubation were not significant predictors, in the context of substantial inter-patient variation. Our results reveal substantial inter-patient variation in TA microbiome structure, limiting our ability to test for significant impacts of clinical category on microbiome structure. Our results provide information for the design of larger-scale studies to evaluate the role of clinical history and specific taxa in governing the interplay between antibiotics and pathogen dynamics in critically ill children.IMPORTANCEClinicians often prescribe empirical antibiotics for critically ill, intubated children with suspected respiratory infections, contributing to antibiotic overuse and challenging antimicrobial stewardship. Our longitudinal tracheal aspirate analysis of cultures and 16S rDNA sequencing revealed significant inter-patient variability, regardless of the primary reason for intubation. We observed both concordance and discrepancies between clinical microbiology and sequencing results-gram-negative organisms aligned well between methods, whereas <i>Streptococcus</i> was detected in 34 of 39 samples by 16S rDNA but only once by culture. Our findings emphasize the value of longitudinal airway microbiome analysis in pediatric patients. Given the heterogeneous pathologies and diverse age groups in pediatric intensive care, future large-scale studies should account for antibiotic exposure, commensal bacterial interactions, and clinical conditions that influence microbiome dynamics. Expanding research in this area could improve our understanding of microbial shifts in critically ill children and inform more targeted treatment strategies.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":" ","pages":"e0044825"},"PeriodicalIF":3.8,"publicationDate":"2025-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145329246","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":"Propionic acid toxicity and utilization of α-ketobutyric acid in <i>Neisseria meningitidis</i> via the methylcitrate cycle under specific conditions.","authors":"Adelfia Talà, Matteo Calcagnile, Silvia Caterina Resta, Salvatore Maurizio Tredici, Giuseppe Egidio De Benedetto, Cecilia Bucci, Pietro Alifano","doi":"10.1128/spectrum.00783-25","DOIUrl":"https://doi.org/10.1128/spectrum.00783-25","url":null,"abstract":"<p><p><i>Neisseria meningitidis</i> is a human-specific, transient colonizer of the nasopharynx that occasionally causes invasive disease. It can utilize a limited range of compounds as primary carbon sources, including glucose, maltose, lactate, and pyruvate, which are present in varying concentrations in microenvironments relevant to meningococcal infection. Additionally, intermediates from the tricarboxylic acid cycle, such as succinate, fumarate, and malate, as well as amino acids like glutamate, are utilized as supplementary carbon sources. Notably, <i>N. meningitidis</i> also possesses a functional methylcitrate cycle (MCC), which enables the assimilation of propionic acid and mitigates its toxicity. In this study, we investigated propionate toxicity and MCC functionality in wild-type <i>N. meningitidis</i> strains and <i>prpB</i>-, <i>prpC</i>-, <i>ackA1-</i>, and <i>ackA2</i>-defective mutants under various growth conditions. We observed that propionate toxicity was influenced by the primary carbon source and additional factors, such as bicarbonate. Specifically, <i>prpB</i>- and <i>prpC</i>-defective mutants showed high sensitivity to propionate when cultured with glucose or pyruvate, but were not inhibited even by high concentrations of propionate when grown with lactate. The mechanisms underlying the conditional toxicity of propionate were further explored and discussed. Additionally, in the genome of 41 out of 128 <i>N</i>. <i>meningitidis</i> strains, we identified a gene encoding a transporter from the 4-toluene sulfonate uptake permease family, located between <i>prpC</i> and <i>acnD</i> in the MCC gene cluster. Genetic inactivation of this gene, named <i>kbuT</i>, impaired the ability to take up and oxidize α-ketobutyrate, an α-keto acid abundant in host cells, which can be used as a carbon source through the MCC.</p><p><strong>Importance: </strong>Meningococci are metabolically versatile organisms, switching between intracellular and extracellular lifestyle during colonization and invasive disease. Niche switching impacts on how bacteria communicate with host to find a balance between nutrient assimilation and protection against toxicity of some metabolites. The methylcitrate pathway fulfills this function, providing a compromise between propionate assimilation and propionate detoxification, in relation to the colonized host microenvironments. In this study, we revealed an unexpected difference in the sensitivity of meningococci to propionate when grown with different carbon sources. We also characterized the function of a gene located within the prp operon that encodes a transporter of α-ketobutyrate, an α-ketoacid abundant in host cells. These results contribute to extending our understanding of the metabolic adaptation mechanisms, which are crucial for meningococcal infection and virulence within the host microenvironments.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":" ","pages":"e0078325"},"PeriodicalIF":3.8,"publicationDate":"2025-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145329369","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":"QuantiFERON-TB Gold Plus CD8+ T cell responses in contacts with tuberculosis disease and recent tuberculosis infection.","authors":"Cynthia Bin-Eng Chee, KhinMar Kyi-Win, Shera Tan, Yee-Tang Wang","doi":"10.1128/spectrum.01353-25","DOIUrl":"https://doi.org/10.1128/spectrum.01353-25","url":null,"abstract":"<p><p>The QuantiFERON-TB Gold Plus (QFT-Plus) replaced the QuantiFERON-TB Gold in-tube (QFT-GIT) in 2016 to increase assay sensitivity, based on the role of <i>Mycobacterium tuberculosis</i>-specific CD8+ T cells in the host response to tuberculosis infection (TBI). The QFT-Plus incorporates a fourth tube (TB2 tube) in addition to the TB antigen tube of the QFT-GIT (TB1 tube). The TB2 tube contains shorter peptides from early secretary antigenic 6 kDa (ESAT-6) and culture filtrate protein 10 (CFP-10) to stimulate CD8+ T cells as well as long peptides contained in the TB1 tube. Evidence that <i>Mycobacterium tuberculosis</i>-specific CD8+ T cells preferentially recognize heavily infected cells has generated interest in the QFT-Plus CD8+ T cell response (taking TB2-TB1 interferon-gamma [IFN-γ] >0.6 IU/mL as a threshold for CD8+ response) as a marker for TB disease and for recent TBI. We retrospectively analyzed the CD8+ responses in the QFT-Plus results of contacts screened at the Singapore TB Contact Clinic from January 2018 to October 2018. We found significantly higher proportions of contacts with TB2-TB1 IFN-γ >0.6 IU/mL among those with TB disease (28.8% vs 12.6%, <i>P</i> < 0.0001) and Stringent Converters (23.3% vs 12.6%, <i>P</i> < 0.0001) compared to All Others with TBI. Median TB2-TB1 IFN-γ values were also significantly higher in those with TB disease (0.13 vs 0.06 IU/mL, <i>P</i> < 0.0001) and Stringent Converters (0.17 vs 0.06 IU/mL, <i>P</i> = 0.036) compared to All Others with TBI. Our findings add to the evidence that the CD8+ response measured by the QFT-Plus assay may predict TB disease and recent TB infection.IMPORTANCEEvidence that <i>Mycobacterium tuberculosis</i>-specific CD8+ T cells preferentially recognize heavily infected cells has generated interest in the QuantiFERON-TB Gold Plus (QFT-Plus) CD8+ T cell response as a marker for tuberculosis (TB) disease and for recent TB infection. Taking TB2-TB1 interferon-gamma >0.6 IU/mL as a threshold for CD8+ response, we found CD8+ T cell response to be associated with TB disease and stringent QFT-Plus conversion in a cohort of contacts screened under our country's national program. This adds to the evidence for the potential utility of this marker to identify persons who would benefit from further investigations for TB disease and those with recent infection who would be candidates for TB preventive treatment.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":" ","pages":"e0135325"},"PeriodicalIF":3.8,"publicationDate":"2025-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145329400","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 adaptive growth and mechanisms of <i>Klebsiella pneumoniae</i> under sucrose and glucose exposure.","authors":"Yunhui He, Fangfang Liu, Congcong Li, Jiayan Wu, Kewei Fan, Zewen Wen, Duoyun Li, Zhijian Yu, Tieying Hou","doi":"10.1128/spectrum.01603-25","DOIUrl":"https://doi.org/10.1128/spectrum.01603-25","url":null,"abstract":"<p><p><i>Klebsiella pneumoniae</i> commonly colonizes the gastrointestinal (GI) mucosa of animals and healthy humans. Successful GI colonization by <i>K. pneumoniae</i> requires overcoming the colonization resistance (CR) exerted by the gut microbiota. Although previous studies have demonstrated the role of microbial carbohydrate metabolism in <i>K. pneumoniae</i> colonization, the specific effects of individual carbohydrates, such as glucose and sucrose, particularly across concentration gradients or under sustained induction on the adaptive growth of <i>K. pneumoniae</i> remain unknown. Herein, we demonstrate that 4% or 8% glucose and sucrose are favorable for promoting adaptive growth of sugar-induced strains. Additionally, the growth response to glucose exhibited strain-specific variability. Sustained sugar induction did not significantly alter the hypermucoviscosity (HMV) phenotype but did affect antibiotic resistance of <i>K. pneumoniae</i>. Knockout of the <i>scrA</i> and <i>scrY</i> genes impaired the adaptive growth under sucrose and glucose conditions, yet did not significantly influence antimicrobial susceptibility or the HMV phenotype. These findings provide insights into the metabolic regulation of <i>K. pneumoniae</i> colonization and offer potential guidance for clinical treatment strategies targeting <i>K. pneumoniae</i>-associated infections.</p><p><strong>Importance: </strong>This work elucidates the impact of single-carbon source gradients and sustained sugar induction on the adaptive growth and drug resistance of <i>Klebsiella pneumoniae</i> and preliminarily reveals the roles of <i>scrA</i> and <i>scrY</i> in carbohydrate metabolism, suggesting a possible mechanism by which sucrose and glucose affect the adaptive growth of <i>K. pneumoniae</i>. These findings contribute to the theoretical understanding of CCR and provide insights that may inform clinical management of <i>K. pneumoniae</i>-related infections.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":" ","pages":"e0160325"},"PeriodicalIF":3.8,"publicationDate":"2025-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145301933","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":"Comparative analysis of vancomycin-resistant enterococci in colonization and infection-a longitudinal study.","authors":"Vera Blaschke, Vera Rauschenberger, Heike Claus, Stefanie Kampmeier","doi":"10.1128/spectrum.01750-25","DOIUrl":"https://doi.org/10.1128/spectrum.01750-25","url":null,"abstract":"<p><p>Vancomycin-resistant <i>Enterococcus faecium</i> (VREfm) carriage in the gastrointestinal tract is a risk factor for the development of an invasive infection. The exact mechanisms underlying the transition from colonization to infection are still unclear. We conducted a longitudinal study, including 54 paired VREfm isolates, consisting of a colonization and a subsequent bloodstream isolate from the same patient. We performed whole-genome sequencing, biofilm formation assays, and spot-on-lawn assays to investigate genotypic and phenotypic characteristics of the isolates. No significant differences in these characteristics between paired colonization and infection isolates were detected. Genotyping revealed that colonization isolates were genetically closely related to their respective infection isolates in 22 of 27 (81%) isolate pairs. Further studies focusing on the interaction between host epithelium and pathogen are needed to gain more insight into the transition from colonization to infection.IMPORTANC<b>E</b>Previous studies have primarily focused on patient-related risk factors associated with the development of vancomycin-resistant <i>Enterococcus faecium</i> (VREfm) infection. However, identifying and characterizing the bacterial factors responsible for this transition is crucial, especially given the limited treatment options for VREfm infection. Our analyses revealed no significant differences between colonization and infection isolates, suggesting that host-pathogen interaction may play a more critical role in this progression and should be further investigated. Moreover, our findings highlight the importance of risk assessment and infection prevention measures to prevent VREfm colonization as a critical step in the development of VREfm infection.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":" ","pages":"e0175025"},"PeriodicalIF":3.8,"publicationDate":"2025-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145301913","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 factors and antimicrobial efficacy: the impact of temperature and humidity on material surfaces.","authors":"Han Cheng, Jie Chen, Hao Yu, Bin Sun, Jialiang Zhou, Guoyi Wu","doi":"10.1128/spectrum.00960-25","DOIUrl":"https://doi.org/10.1128/spectrum.00960-25","url":null,"abstract":"<p><p>Current International Standards Organization (ISO) for testing antimicrobial materials often lack regulatory approval for clinical use because they do not accurately reflect real-world environmental conditions. In this study, we systematically evaluated the effects of temperature (4°C-37°C) and humidity (15%-100% relative humidity) on microbial survival (<i>Staphylococcus aureus</i>, <i>Escherichia coli</i>, HCoV-OC43, and influenza virus) and the efficacy of various antimicrobial surfaces (stainless steel, copper, polyethylene terephthalate [PET], and Cu₂O@ZrP-modified PET) using established ISO standards, including ISO 21702, 18184, 22196, and 20743. We found that pathogen survival declined sharply with increasing temperature, while the effects of humidity varied by material. Copper and Cu₂O@ZrP-PET surfaces achieved greater than 99% viral and bacterial inactivation within 60 min; however, their activity was delayed by two to threefold at 4°C. The effects of humidity were material-dependent. Non-porous copper maintained consistent efficacy across humidity levels, whereas PET/Cu₂O@ZrP exhibited enhanced antibacterial activity under low humidity. Mechanistically, reactive oxygen species generation correlated with efficacy changes across conditions. We advocate revising ISO protocols to include dynamic environmental parameters and propose a tiered classification of antimicrobial efficiency that aligns with clinical demands. This framework addresses the discrepancy between laboratory tests and real-world performance, enabling the robust evaluation of antimicrobial materials for clinical and public health applications.IMPORTANCEThis study addresses a critical gap in our understanding of how real-world environmental conditions affect the performance of antimicrobial materials. Current International Standards Organization (ISO) testing standards fail to adequately account for temperature and humidity variations, leading to discrepancies between laboratory results and real-world effectiveness. Our findings demonstrate that both temperature and humidity significantly impact pathogen survival and antimicrobial efficacy, with important implications for material selection in healthcare, public spaces, and pandemic preparedness. By systematically evaluating these environmental factors across different material types, we provide evidence-based recommendations for revising international testing protocols. This work is essential for ensuring that antimicrobial materials perform as expected when deployed in actual environments, potentially saving lives by improving the reliability of these critical defense mechanisms against infectious diseases.</p>","PeriodicalId":18670,"journal":{"name":"Microbiology spectrum","volume":" ","pages":"e0096025"},"PeriodicalIF":3.8,"publicationDate":"2025-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145301930","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}