Research in microbiology最新文献_第2页

Adh1-Car1 axis regulates dimorphic transition in Candida albicans by suppressing hyphal hyperelongation Adh1-Car1轴通过抑制菌丝超长调节白色念珠菌二态转变。

IF 3.4 4区生物学

Research in microbiology Pub Date : 2025-09-01 DOI: 10.1016/j.resmic.2025.104322

Ziran Wang, Yuanyuan Lu

{"title":"Adh1-Car1 axis regulates dimorphic transition in Candida albicans by suppressing hyphal hyperelongation","authors":"Ziran Wang, Yuanyuan Lu","doi":"10.1016/j.resmic.2025.104322","DOIUrl":"10.1016/j.resmic.2025.104322","url":null,"abstract":"<div><div><em>Candida albicans</em>, a prevalent opportunistic fungal pathogen, employs dimorphic transition (yeast-to-hypha) as a central strategy for host tissue invasion and immune evasion. Although prior studies have linked <em>ADH1</em> deletion to attenuated virulence phenotypes such as impaired hyphal formation, the molecular mechanism underlying this phenomenon remains elusive. Here, we report that <em>ADH1</em> knockout strains exhibit a striking hyperelongation of hyphae, deviating from the characteristic branched architecture observed in wild-type strains. Transcriptomic profiling identified arginine metabolism as the most significantly activated pathway in <em>adh1Δ/Δ</em> mutants, with marked upregulation of <em>CAR1</em>, encoding a key arginase. Crucially, pharmacological or genetic inhibition of Car1 activity fully restores wild-type hyphal morphology in <em>ADH1</em> knockout strains, unequivocally establishing that <em>ADH1</em> governs hyphal development through repression of <em>CAR1</em> expression. Our findings delineate the Adh1-Car1 metabolic axis as a master regulator of dimorphic switching in <em>C. albicans</em>: while Adh1 constrains Car1 to maintain balanced hyphal branching, its deletion triggers arginine metabolic flux dyshomeostasis, driving uncontrolled hyphal hyperelongation. This work redefines the functional paradigm of Adh1 beyond its canonical role in ethanol metabolism, positions fungal metabolic rewiring as a direct driver of morphogenic plasticity, and nominates the Adh1-Car1 axis as a high-value target for antifungal interventions.</div></div>","PeriodicalId":21098,"journal":{"name":"Research in microbiology","volume":"176 7","pages":"Article 104322"},"PeriodicalIF":3.4,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144966768","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Emerging concept of genomic islands in bacterial adaptation and pathogenicity 基因组岛在细菌适应和致病性中的新概念。

IF 3.4 4区生物学

Research in microbiology Pub Date : 2025-09-01 DOI: 10.1016/j.resmic.2025.104303

Ingita Dey Munshi , Anshu Mathuria , Harshita Sharma , Mansi Acharya , Anushika Chaudhary , Kritika Jain , Ragini , Sakshi Dahiya , Reet Arora , Vijai Singh , Ashok Saini , Indra Mani

引用次数: 0

Transcriptome analysis during thermal-induced endogenous mutagenesis in a strict psychrotrophic Aeromonas salmonicida subp. salmonicida strain 严格嗜冷养型沙门氏气单胞菌亚群热诱导内源性突变的转录组。salmonicida压力。

IF 3.4 4区生物学

Research in microbiology Pub Date : 2025-09-01 DOI: 10.1016/j.resmic.2025.104305

Javier Santander , Ahmed Hossain , Katherine Valderrama , Jules Hermet , Trung Cao , Oluwatoyin Onireti , Ignacio Vasquez , Hajarooba Gnanagobal

{"title":"Transcriptome analysis during thermal-induced endogenous mutagenesis in a strict psychrotrophic Aeromonas salmonicida subp. salmonicida strain","authors":"Javier Santander , Ahmed Hossain , Katherine Valderrama , Jules Hermet , Trung Cao , Oluwatoyin Onireti , Ignacio Vasquez , Hajarooba Gnanagobal","doi":"10.1016/j.resmic.2025.104305","DOIUrl":"10.1016/j.resmic.2025.104305","url":null,"abstract":"<div><div><em>Aeromonas salmonicida</em> is one of the earliest identified fish pathogens and the causative agent of furunculosis. <em>A. salmonicida</em> can be cultivated at temperatures as high as 30 °C, but at temperatures over 24 °C, insertion sequence (IS) elements cause endogenous mutagenesis. Here, we used a phenotypical and transcriptomics analysis to study the molecular aspects of <em>A. salmonicida</em> endogenous mutagenesis. Endogenous mutagenesis became evident after 12 h post-thermal induction and reached the highest level after 24 h. RNA was extracted from <em>A. salmonicida</em> grown at 15 and 28 °C after 16 h. Differential gene expression analysis showed that 344 differential expressed genes were up-regulated and 364 were down-regulated at 28 °C. Several ISs were upregulated in the chromosome and virulence plasmid. Virulence genes, including the type 3 secretion system, A-layer, and melanin synthesis, were downregulated. Overall, our result indicates that <em>A. salmonicida</em> incubated at 28 °C was under moderate heat stress but under strong stress caused by ISs mutagenesis. These results align with the hypothesis that ISs constrain virulent <em>A. salmonicida</em> to a psychrotrophic lifestyle, potentially transitioning to an attenuated mesophilic lifestyle.</div></div>","PeriodicalId":21098,"journal":{"name":"Research in microbiology","volume":"176 7","pages":"Article 104305"},"PeriodicalIF":3.4,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144637884","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Nutrients drive the antibiotic-specific evolution of resistance in Pseudomonasaeruginosa. 营养物质驱动铜绿假单胞菌耐药性的抗生素特异性进化。

IF 3.4 4区生物学

Research in microbiology Pub Date : 2025-09-01 DOI: 10.1016/j.resmic.2025.104323

Maik Kok, Laura B Zwep, Robert S Jansen, Thomas Hankemeier, J G Coen van Hasselt

{"title":"Nutrients drive the antibiotic-specific evolution of resistance in Pseudomonasaeruginosa.","authors":"Maik Kok, Laura B Zwep, Robert S Jansen, Thomas Hankemeier, J G Coen van Hasselt","doi":"10.1016/j.resmic.2025.104323","DOIUrl":"10.1016/j.resmic.2025.104323","url":null,"abstract":"<p><p>Pseudomonas aeruginosa can exploit its metabolic flexibility during cystic fibrosis lung infections to reduce antibiotic sensitivity and offset resistance costs, traits that influence its evolutionary trajectory. Although both traits are linked to nutrient conditions, their role in resistance evolution remains poorly defined. We examined how single-nutrient conditions influence resistance evolution in P. aeruginosa through phenotypic and genotypic adaptations after adaptive laboratory evolution with different antibiotics in single-nutrient media. Antibiotic susceptibility testing showed limited MIC differences for ceftazidime and imipenem, but stronger effects for ciprofloxacin, colistin, and tobramycin. Ciprofloxacin evolution in glutamate medium yielded the highest MIC increase, with at least a 4-fold rise, whereas tobramycin evolution in glucose resulted in up to a 4-fold MIC reduction compared to lineages evolved under all other nutrient conditions for the same antibiotic. Whole-genome sequencing showed nutrient-specific mutation in wbpL after tobramycin evolution in glucose, and fusA and pmrB across conditions. Ciprofloxacin resistance in glutamate-lineages involved yicC, whereas nfxB mutations were absent in glucose- and arginine-evolved lineages. No distinct nutrient-specific differences were seen for colistin. These findings underscore the significant role of nutrient conditions in shaping resistance and highlight the need to consider physiologically relevant media when studying antibiotic resistance evolution.</p>","PeriodicalId":21098,"journal":{"name":"Research in microbiology","volume":" ","pages":"104323"},"PeriodicalIF":3.4,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144993353","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Multi-drug resistance and diversity of mobile genetic elements in Escherichia coli isolated from migratory bird in Poyang Lake 鄱阳湖候鸟大肠杆菌多药耐药及移动基因多样性分析

IF 3.4 4区生物学

Research in microbiology Pub Date : 2025-09-01 DOI: 10.1016/j.resmic.2025.104306

Haixin Deng , Huiping Liang , Qinghua Zeng , Peng Huang , Hui Yan , Huabin Cao , Huansheng Wu

{"title":"Multi-drug resistance and diversity of mobile genetic elements in Escherichia coli isolated from migratory bird in Poyang Lake","authors":"Haixin Deng , Huiping Liang , Qinghua Zeng , Peng Huang , Hui Yan , Huabin Cao , Huansheng Wu","doi":"10.1016/j.resmic.2025.104306","DOIUrl":"10.1016/j.resmic.2025.104306","url":null,"abstract":"<div><div>With the spread of antibiotic resistance genes such as blaCTX-M-2, dfrA1 and blaNDM-1, the problem of drug resistance in <em>E. coli</em> is becoming increasingly serious [1]. This study aimed to identify integrons genes and MGEs in <em>E. coli</em> isolated from migratory birds' feces at Poyang Lake, Jiangxi Province, focusing on their role in antimicrobial resistance (AMR). The 114 isolated <em>E. coli</em> strains were tested by standard disk diffusion method and genetic testing method. Results showed 64.04 % (73/114) of isolates were multi-drug resistance (MDR), mainly resistant to 3–6 antibiotics. Common resistances included neomycin (50 %) and streptomycin (48.25 %). We detected 21 mobile genetic elements, including IS903 (92.11 %), traA (72.81 %), ISCR3 (64.91 %), and ISpa7 (50 %). These elements were present in all isolates, forming 112 combinations. Significant differences in resistance rates were found between class I integron-positive and negative strains for doxycycline, tetracycline, bacitracin, and streptomycin (P < 0.01), and for neomycin (P < 0.05). Class II integron-positive bacteria showed higher resistance to doxycycline (P < 0.01) and ceftizoxime (P < 0.05). No significant differences were observed for class III integron-positive strains. This study underscores the prevalence of multidrug-resistant and the diversity of mobile genetic elements in <em>E. coli</em>, emphasizing the need for continuous monitoring.</div></div>","PeriodicalId":21098,"journal":{"name":"Research in microbiology","volume":"176 7","pages":"Article 104306"},"PeriodicalIF":3.4,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144619949","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Metabolic adaptation via glycolysis and iron acquisition drives Klebsiella pneumoniae–induced intraocular inflammation and visual impairment 通过糖酵解和铁获取的代谢适应驱动肺炎克雷伯菌引起的眼内炎症和视力损害。

IF 3.4 4区生物学

Research in microbiology Pub Date : 2025-09-01 DOI: 10.1016/j.resmic.2025.104321

Ping Lu , Juan Xue , Xuemeng Ji

{"title":"Metabolic adaptation via glycolysis and iron acquisition drives Klebsiella pneumoniae–induced intraocular inflammation and visual impairment","authors":"Ping Lu , Juan Xue , Xuemeng Ji","doi":"10.1016/j.resmic.2025.104321","DOIUrl":"10.1016/j.resmic.2025.104321","url":null,"abstract":"<div><div><em>Klebsiella pneumoniae</em> is a major cause of endogenous endophthalmitis, a rapidly progressing intraocular infection associated with severe inflammation and vision loss. The vitreous body presents a hypoxic and iron-restricted environment, yet the bacterial metabolic adaptations that enable persistence in this niche remain largely unknown. Here, we show that <em>K. pneumoniae</em> undergoes metabolic reprogramming to facilitate intraocular survival, characterized by enhanced glycolysis and siderophore-mediated iron acquisition. Proteomic profiling under vitreous-mimicking conditions revealed significant upregulation of PfkA, PykF, and EntB. Targeted deletion of these genes impaired bacterial growth under hypoxia and iron limitation, and significantly reduced intraocular colonization, proinflammatory cytokine production, and visual impairment in a murine model. Double mutants lacking both glycolytic and iron acquisition pathways were nearly avirulent. Correspondingly, infected eyes exhibited lower levels of lactate and iron, reflecting reduced bacterial metabolic activity. These findings establish glycolysis and iron acquisition as critical determinants of <em>K. pneumoniae</em> virulence in the eye and provide insight into the metabolic strategies underpinning bacterial persistence in nutrient-limited host environments.</div></div>","PeriodicalId":21098,"journal":{"name":"Research in microbiology","volume":"176 7","pages":"Article 104321"},"PeriodicalIF":3.4,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144856160","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Functional diversity of AI-2/LuxS system in lactic acid bacteria: Impacts on biofilm formation and environmental resilience 乳酸菌AI-2/LuxS系统的功能多样性：对生物膜形成和环境恢复力的影响

IF 2.5 4区生物学

Research in microbiology Pub Date : 2025-07-01 DOI: 10.1016/j.resmic.2025.104296

Hopeful Tusalifye Kanthenga , Riza Jane S. Banicod , Wilson Ntege , Moses Njeru Njiru , Aqib Javaid , Nazia Tabassum , Young-Mog Kim , Fazlurrahman Khan

引用次数: 0

Effect of Pseudomonas aeruginosa ExoU on airway epithelial cells through MUC1-C nuclear translocation 铜绿假单胞菌ExoU通过MUC1-C核易位对气道上皮细胞的影响。

IF 2.5 4区生物学

Research in microbiology Pub Date : 2025-07-01 DOI: 10.1016/j.resmic.2025.104301

Alexandre Costa Monteiro , Karen Rosalino Emmerick , Lhousseine Touqui , Alessandra Mattos Saliba

{"title":"Effect of Pseudomonas aeruginosa ExoU on airway epithelial cells through MUC1-C nuclear translocation","authors":"Alexandre Costa Monteiro , Karen Rosalino Emmerick , Lhousseine Touqui , Alessandra Mattos Saliba","doi":"10.1016/j.resmic.2025.104301","DOIUrl":"10.1016/j.resmic.2025.104301","url":null,"abstract":"<div><div>The opportunistic pathogen <em>Pseudomonas aeruginosa</em> plays a significant role in hospital-acquired pneumonia, with the secretion of ExoU - a virulence factor expressed by select <em>P. aeruginosa</em> strains - linked to poor clinical outcomes. This is due to ExoU's phospholipase A<sub>2</sub> activity, which triggers an uncontrolled inflammatory response, leading to severe pathologies. Here, we delve into ExoU's impact on mucin-1 (MUC1), a critical mucus component with immunomodulatory properties on pulmonary cell surfaces. Our findings reveal that infection of human respiratory epithelial cells by an ExoU-negative <em>P. aeruginosa</em> strain boosts MUC1 expression, yet ExoU secretion by the bacteria diminishes MUC1 mRNA and protein levels through JNK pathway disruption. Interestingly, despite reduced overall cell-associated MUC1 levels, ExoU prompts MUC1 accumulation within the nucleus, where the MUC1 cytoplasmic tail (MUC1-C) may act as a transcriptional coactivator. Notably, treating epithelial respiratory cell cultures with GO-201, a specific MUC1-C inhibitor, diminished CXCL-8 secretion induced by ExoU. In essence, our study highlights how infection by ExoU-producing <em>P. aeruginosa</em> strains suppresses MUC1 expression during infection, while enhancing MUC1-C translocation to the nucleus, where it plays a pro-inflammatory role. This unique mechanism sheds light on how ExoU can impact the host's defense against <em>P. aeruginosa</em>, potentially compromising host health.</div></div>","PeriodicalId":21098,"journal":{"name":"Research in microbiology","volume":"176 5","pages":"Article 104301"},"PeriodicalIF":2.5,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144275818","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

2-Chloromethyl anthraquinone inhibits Candida albicans biofilm formation by inhibiting the Ras1-cAMP-Efg1 pathway 2-氯甲基蒽醌通过抑制Ras1-cAMP-Efg1通路抑制白色念珠菌生物膜形成

IF 2.5 4区生物学

Research in microbiology Pub Date : 2025-07-01 DOI: 10.1016/j.resmic.2025.104280

Haoying Zhang, Qi Zhang, Ting Zuo, Ziqi Wang, Jianmin Liao, Yuanyuan Lu

{"title":"2-Chloromethyl anthraquinone inhibits Candida albicans biofilm formation by inhibiting the Ras1-cAMP-Efg1 pathway","authors":"Haoying Zhang, Qi Zhang, Ting Zuo, Ziqi Wang, Jianmin Liao, Yuanyuan Lu","doi":"10.1016/j.resmic.2025.104280","DOIUrl":"10.1016/j.resmic.2025.104280","url":null,"abstract":"<div><div><em>Candida albicans</em> is an opportunistic pathogen, and the formation of its biofilm makes it resistant to traditional antifungal therapy. Anthraquinones have universal antibacterial activity. We evaluated the inhibitory effects of 2-chloromethyl anthraquinone on <em>C. albicans</em> adhesion, mycelial morphology transformation, and biofilm formation. The results showed that 2-chloromethyl anthraquinone could inhibit <em>C. albicans</em> adhesion, mycelium formation, and biofilm formation in a dose-dependent manner at 2 μg/mL. In addition, 2-chloromethyl anthraquinone significantly inhibited the expression of biofilm formation-related genes in <em>C. albicans</em>, including <em>ALS1</em>, <em>CPH1</em>, <em>ECE1</em>, <em>HWP1</em>, <em>TEC1</em>, <em>BCR1</em>, and <em>UME6</em>. In addition, Ras1-cAMP-Efg1 pathway-related genes (<em>RAC1</em>, <em>CYR1</em>, and <em>TPK2</em>) were also significantly down-regulated, indicating that the inhibitory effect of 2-chloromethyl anthraquinone on <em>C. albicans</em> biofilms may be related to the Ras1-cAMP-Efg1 signaling pathway. In summary, the results of this study confirmed the inhibitory mechanism of 2-chloromethyl anthraquinone on the virulence factors of <em>C. albicans</em>, which laid a theoretical foundation for its use as an anti-biofilm agent against <em>C. albicans</em>.</div></div>","PeriodicalId":21098,"journal":{"name":"Research in microbiology","volume":"176 5","pages":"Article 104280"},"PeriodicalIF":2.5,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143536853","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Switching off the yeast-to-hyphae transition in Yarrowia lipolytica through histone deacetylase inhibitors 通过组蛋白去乙酰化酶抑制剂关闭脂性耶氏菌酵母到菌丝的转化。

IF 2.5 4区生物学

Research in microbiology Pub Date : 2025-07-01 DOI: 10.1016/j.resmic.2025.104299

Martha Viviana Roa-Cordero , Christian Alfonso Arenas-Sepúlveda , María Cristina Herrera-Plata , Sandra Milena Leal-Pinto , Nubia Andrea Villota-Salazar , Juan Manuel González-Prieto

{"title":"Switching off the yeast-to-hyphae transition in Yarrowia lipolytica through histone deacetylase inhibitors","authors":"Martha Viviana Roa-Cordero , Christian Alfonso Arenas-Sepúlveda , María Cristina Herrera-Plata , Sandra Milena Leal-Pinto , Nubia Andrea Villota-Salazar , Juan Manuel González-Prieto","doi":"10.1016/j.resmic.2025.104299","DOIUrl":"10.1016/j.resmic.2025.104299","url":null,"abstract":"<div><div>Fungi can develop a variety of morphotypes to survive, colonize, adapt and prevail under different environmental conditions. In general, two morphological shapes encompass the others: yeast (unicellular) and hyphae (multicellular). Under specific conditions, some fungi can adopt these two cellular morphologies, and for this reason, they are called dimorphic. Histone acetylation and deacetylation are well-known important mechanisms of chromatin remodelling that control cell differentiation processes as dimorphism. The reactions involved are catalysed by histone acetyltransferases (HATs) and histone deacetylases (HDACs), respectively. In the present work, we used <em>Yarrowia lipolytica</em> as a dimorphic fungal model to investigate the effect of HDAC chemical inhibition on the growth and yeast-to-hyphae switch of fungi. For this purpose, we tested the compounds sodium butyrate (SB) and valproic acid (VPA) as epigenetic modulators. Our results indicated that <em>Y. lipolytica</em> tolerates high doses of these inhibitors due to its lipolytic nature. However, once the metabolic capability of the fungus is overcome, SB and VPA strongly suppress hyphal growth, suggesting that histone acetylation plays a pivotal role in the regulation of this process.</div></div>","PeriodicalId":21098,"journal":{"name":"Research in microbiology","volume":"176 5","pages":"Article 104299"},"PeriodicalIF":2.5,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143993846","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0