Fems Microbiology Letters最新文献_第5页

Azospirillum brasilense and cytidine enhance lateral roots of peas. 巴西氮螺旋菌和胞苷增强豌豆侧根。

IF 2.2 4区生物学

Fems Microbiology Letters Pub Date : 2025-01-10 DOI: 10.1093/femsle/fnaf025

Fatema A Nisha, Shelley M Horne, Birgit M Prüß

{"title":"Azospirillum brasilense and cytidine enhance lateral roots of peas.","authors":"Fatema A Nisha, Shelley M Horne, Birgit M Prüß","doi":"10.1093/femsle/fnaf025","DOIUrl":"10.1093/femsle/fnaf025","url":null,"abstract":"Azospirillum brasilense is a plant growth beneficial rhizobacterium (PGBR) that is used as an inoculant to enhance root architecture in grassland and crop plants. The intent of our study was to develop A. brasilense into a probiotic inoculant for peas and supplement with a seedling exudate compound, to be used together or separately. As an initial characterization of the association of A. brasilense with pea roots, we performed several pea growth experiments. Azospirillum brasilense Sp7T increased the lengths of the five longest lateral roots from each plant by 63.6% and the top 10 lateral roots across 14 plants by 30%, an effect that was abolished in an rpoN mutant and a ΔcheA1/cheA4 mutant. Azospirillum brasilense Cd increased the number of lateral roots by 76%. We detected colonization by this PGBR within the epiphytic root microbiome. To identify a pea seedling exudate compound capable of enhancing lateral pea roots, we tested 15 such compounds. Cytidine was the only one that increased the number of lateral roots, by approximately two-fold, an effect that did not require A. brasilense. We conclude that both A. brasilense and cytidine might be suitable as supplements to enhance lateral roots of pea plants.","PeriodicalId":12214,"journal":{"name":"Fems Microbiology Letters","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143556214","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

Testosterone and estradiol regulate the expression of proteases and a hemoglobinase in Actinobacillus seminis. 睾酮和雌二醇调节半放线杆菌中蛋白酶和血红蛋白酶的表达。

IF 2.2 4区生物学

Fems Microbiology Letters Pub Date : 2025-01-10 DOI: 10.1093/femsle/fnaf097

Gerardo A Ramírez-Paz-Y-Puente, José A Gutiérrez-Pabello, Edgar Zenteno, Tomás E Villamar-Duque, Erika P Meneses-Romero, Candelario Vazquez-Cruz, Erasmo Negrete-Abascal

{"title":"Testosterone and estradiol regulate the expression of proteases and a hemoglobinase in Actinobacillus seminis.","authors":"Gerardo A Ramírez-Paz-Y-Puente, José A Gutiérrez-Pabello, Edgar Zenteno, Tomás E Villamar-Duque, Erika P Meneses-Romero, Candelario Vazquez-Cruz, Erasmo Negrete-Abascal","doi":"10.1093/femsle/fnaf097","DOIUrl":"10.1093/femsle/fnaf097","url":null,"abstract":"Actinobacillus seminis is a causative agent of epididymitis, infertility, and sterility in sexually mature ruminants. Previous studies suggest that sex hormones regulate the expression of A. seminis virulence factors, promote its growth, and support adhesin expression and biofilm formation; however, the effects of these hormones on protease expression are unknown. The effects of testosterone (1-5 ng/ml) and estradiol (5-25 pg/ml) were evaluated on the A. seminis protease expression. Zymograms revealed that both hormones enhanced the secretion of a 50 kDa metalloprotease and a 65 kDa serine protease. The 65 kDa serine protease showed optimal activity at a pH of 6-8, was stable at temperatures up to 70°C, and hydrolyzed bovine hemoglobin and casein; interestingly, this hemoglobin protease was expressed after treatment with sex steroid hormones but not in the presence of catecholamines. This serine-protease presents identity with two A. seminis serine proteases of 50 kDa. The metalloprotease has previously been shown to hydrolyze bovine IgG and fibrinogen and presented identity with a carboxy-terminal protease. Both proteases showed immune cross-reactivity with hyperimmune sera against metalloproteases from A. seminis and Actinobacillus pleuropneumoniae, and with serum against a Mannheimia haemolytica serine protease. Our results suggest that hormones affect the expression of different A. seminis virulence factors, such as proteases, and may play a key role in bacterial pathogenesis.","PeriodicalId":12214,"journal":{"name":"Fems Microbiology Letters","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145091492","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

The GATA factor AreB regulates nitrogen metabolism, fungal development, and aflatoxin production in Aspergillus flavus. GATA因子AreB调节黄曲霉的氮代谢、真菌发育和黄曲霉毒素产生。

IF 2.2 4区生物学

Fems Microbiology Letters Pub Date : 2025-01-10 DOI: 10.1093/femsle/fnae110

Qing-Qing Zhi, Zhen-Long Wang, Pei-Bo Yuan, Lei He, Zhu-Mei He

{"title":"The GATA factor AreB regulates nitrogen metabolism, fungal development, and aflatoxin production in Aspergillus flavus.","authors":"Qing-Qing Zhi, Zhen-Long Wang, Pei-Bo Yuan, Lei He, Zhu-Mei He","doi":"10.1093/femsle/fnae110","DOIUrl":"10.1093/femsle/fnae110","url":null,"abstract":"Nitrogen is important for fungal growth and development, and the GATA transcription factor AreA has been widely studied as a key regulator of nitrogen catabolite repression (NCR) in many fungi. However, AreB, another GATA transcription factor in the NCR pathway, remains less studied, and its role in Aspergillus flavus is still unclear. In this study, we characterized areB in A. flavus and investigated its role in regulating nitrogen utilization, fungal growth, and aflatoxin production. The areB gene produces three transcripts, with areB-α being the most abundantly expressed, particularly under nitrogen-limited conditions. Gene expression analysis via qPCR confirmed that areB acts as a negative regulator of NCR, as its deletion led to the upregulation of NCR-related genes under nitrogen-limiting conditions. Gene function analysis of areB revealed that its deletion impaired hyphal growth, reduced conidia production, and delayed conidial germination. Additionally, deletion of areB led to increased aflatoxin production, particularly under less favorable nitrogen sources, while overexpression of areB reduced aflatoxin levels. Furthermore, areB influenced sclerotia formation in a nitrogen-source-dependent manner. These findings reveal the multifaceted role of areB in nitrogen regulation, fungal development, and secondary metabolism, offering insights for controlling aflatoxin contamination and fungal growth.","PeriodicalId":12214,"journal":{"name":"Fems Microbiology Letters","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142863895","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

Biochemical characterization of diaminopimelate decarboxylase from the hyperthermophile Thermotoga maritima. 超嗜热菌海洋热菌二氨基乙酸脱羧酶的生化特性研究。

IF 2.2 4区生物学

Fems Microbiology Letters Pub Date : 2025-01-10 DOI: 10.1093/femsle/fnaf024

Tetsuya Miyamoto, Akari Yazawa, Rio Mishima, Kumiko Sakai-Kato

引用次数: 0

SoxR-dependent regulation of sodA1 and its impact on Stenotrophomonas maltophilia survival under external oxidative stress. soxr依赖性sodA1调控及其对嗜麦芽窄养单胞菌外部氧化应激存活的影响

IF 2.2 4区生物学

Fems Microbiology Letters Pub Date : 2025-01-10 DOI: 10.1093/femsle/fnae112

Suparat Giengkam, Nisanart Charoenlap, Wirongrong Whangsuk, Kisana Bhinija, Skorn Mongkolsuk, Paiboon Vattanaviboon

{"title":"SoxR-dependent regulation of sodA1 and its impact on Stenotrophomonas maltophilia survival under external oxidative stress.","authors":"Suparat Giengkam, Nisanart Charoenlap, Wirongrong Whangsuk, Kisana Bhinija, Skorn Mongkolsuk, Paiboon Vattanaviboon","doi":"10.1093/femsle/fnae112","DOIUrl":"10.1093/femsle/fnae112","url":null,"abstract":"Stenotrophomonas maltophilia is an emerging global opportunistic pathogen that causes nosocomial infections. We demonstrated that the superoxide stress-sensing transcriptional regulator SoxR directly modulated the expression of an operon encompassing sodA1 (encoding manganese-containing superoxide dismutase) and fre (encoding putative flavin reductase) by directly binding to the operator site, which was located between the -35 and -10 motifs of the sodA1 promoter. It is known that upon exposure to the superoxide generators/redox-cycling drugs, the SoxR, which is bound to the operator site, became oxidized. This oxidation causes a conformational change of SoxR to an active form, enabling the upregulation of sodA1-fre gene expression. A ΔsodA1 was constructed, and the mutant showed enhanced sensitivity to the redox-cycling drugs, including menadione, plumbagin, and methyl viologen (paraquat), relative to its parental strain K279a. Thus, sodA1 may play a role in the survival of S. maltophilia under superoxide stress during either its saprophyte stage (e.g. exposure to redox-cycling drugs) or host-pathogen interactions.","PeriodicalId":12214,"journal":{"name":"Fems Microbiology Letters","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142885298","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

Identifying pivotal sites affecting thermostability of GH11 xylanase via conventional and deep learning-based energy calculation. 通过常规和基于深度学习的能量计算确定影响GH11木聚糖酶热稳定性的关键位点。

IF 2.2 4区生物学

Fems Microbiology Letters Pub Date : 2025-01-10 DOI: 10.1093/femsle/fnaf072

Sisi Zhang, Diao Xiong, Xuejun Lin, Lihong Jiang, Wenhua Pi, Xinghua Dai, Nanyu Han

{"title":"Identifying pivotal sites affecting thermostability of GH11 xylanase via conventional and deep learning-based energy calculation.","authors":"Sisi Zhang, Diao Xiong, Xuejun Lin, Lihong Jiang, Wenhua Pi, Xinghua Dai, Nanyu Han","doi":"10.1093/femsle/fnaf072","DOIUrl":"10.1093/femsle/fnaf072","url":null,"abstract":"The GH11 xylanase XynCDBFV, derived from Neocallimastix patriciarum, is widely used in various industries. However, its relatively low thermostability limits its potential. In this study, two computational approaches-Rosetta Cartesian_ddG and the deep learning-based tool Pythia-were employed to identify key residues affecting XynCDBFV thermostability. Both methods highlighted residues D57 and G201 as promising targets. Site-saturation mutagenesis at these positions yielded 18 variants with improved thermostability. Notably, three D57 variants (D57N/S/T) exhibited a 10°C increase in optimal temperature and retained 3.4%-21.7% higher residual activity than the wild type after 1-h incubation at 80°C. Five G201 variants (G201A/C/F/I/V) showed 5°C/10°C enhancements in optimal temperatures, with 10.1%-22.6% improved residual activity. These findings validate D57 and G201 as pivotal sites influencing thermostability. However, combining beneficial mutations from both sites led to reduced thermostability due to negative epistatic interactions. Comparative analysis revealed that while Rosetta Cartesian_ddG offers broader screening, it suffers from a high false discovery rate. In contrast, Pythia provides a balanced trade-off between precision and speed. This study offers a robust framework for enzyme thermostability enhancement and underscores the value of integrating computational predictions with experimental validation in protein engineering.","PeriodicalId":12214,"journal":{"name":"Fems Microbiology Letters","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144607886","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

Comprehensive plasmidomic analysis of Helicobacter pylori reveals the potential role of plasmids in pathogenic adaptation and a novel putative toxin-antitoxin system. 对幽门螺杆菌的质粒组学分析揭示了质粒在病原菌适应和新的毒素-抗毒素系统中的潜在作用。

IF 2.2 4区生物学

Fems Microbiology Letters Pub Date : 2025-01-10 DOI: 10.1093/femsle/fnaf092

Bradd Mendoza-Guido, Juan D Romero-Carpio, Silvia Molina-Castro

{"title":"Comprehensive plasmidomic analysis of Helicobacter pylori reveals the potential role of plasmids in pathogenic adaptation and a novel putative toxin-antitoxin system.","authors":"Bradd Mendoza-Guido, Juan D Romero-Carpio, Silvia Molina-Castro","doi":"10.1093/femsle/fnaf092","DOIUrl":"10.1093/femsle/fnaf092","url":null,"abstract":"Helicobacter pylori is a significant human pathogen associated with gastric diseases, yet the contribution of plasmids to its pathogenicity remains largely unexplored. In this study, we combined plasmid network analysis, dereplication, functional annotation, and phylogenetic approaches to provide a comprehensive genomic and functional characterization of the H. pylori plasmidome using publicly available plasmid sequences. Of 322 plasmids analyzed, we identified 158 high-confidence plasmid sequences, representing 76 non-redundant plasmids (NR-plasmids). Notably, several sequences previously annotated as plasmids were reclassified as Integrative and Conjugative Elements. NR-plasmids were enriched in genes encoding Filamentation induced by cAMP (Fic) family proteins, which clustered into two distinct phylogenetic groups. Conserved motif analysis suggests that these two Fic protein types may form a novel toxin-antitoxin (TA) system, with Type-2 proteins potentially suppressing Type-1 activity, analogous to the TA mechanism described in Campylobacter fetus subsp. venerealis. Additionally, we identified genes encoding ATP-binding cassette (ABC) and major facilitator superfamily efflux pumps, as well as the virulence-associated protein D (VapD), which may contribute to antimicrobial resistance and host colonization, respectively. Our findings reveal the genomic and functional diversity of the H. pylori plasmidome and highlight the need for experimental validation to clarify its role in pathogenicity, antimicrobial resistance, and bacterial adaptation.","PeriodicalId":12214,"journal":{"name":"Fems Microbiology Letters","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144948201","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

Research on the traceability and transmission factors of Salmonella in the broiler production chain: A one health perspective. 肉鸡生产链中沙门氏菌溯源及传播因素研究：一个健康视角。

IF 2.2 4区生物学

Fems Microbiology Letters Pub Date : 2025-01-10 DOI: 10.1093/femsle/fnaf074

Haoran Wang, Yaoyao Zhai, Ge Zhao, Xiuli Zuo, Juan Wang, Xiyue Zhang, Junwei Wang, Lin Wang, Zhina Qu

{"title":"Research on the traceability and transmission factors of Salmonella in the broiler production chain: A one health perspective.","authors":"Haoran Wang, Yaoyao Zhai, Ge Zhao, Xiuli Zuo, Juan Wang, Xiyue Zhang, Junwei Wang, Lin Wang, Zhina Qu","doi":"10.1093/femsle/fnaf074","DOIUrl":"10.1093/femsle/fnaf074","url":null,"abstract":"Salmonella contamination in chicken is a food safety problem that is widely concerned by all countries around the world. Based on the \"One Health\" concept, this study systematically collected samples from animals, the environment and workers across 5 stages of the broiler production chain (breeding farms, hatcheries, commercial broiler farms, slaughterhouses, retail) in China, to investigate the prevalence of Salmonella. Meanwhile, based on whole genome sequencing and risk assessment technology, combined with MLST, cgMLST traceability analysis was conducted to clarify the critical control points and transmission factors associated with Salmonella contamination. The results showed that the prevalence rate of Salmonella in the broiler production chain was 10.22% (469/4589). The broiler production chain encompassed 11 serotypes of Salmonella, with S.Enteritidis ran through the entire production chain. Fourteen types of ST were detected from 99 representative strains, and the dominant types were ST11, ST198 and ST1543. ST11 covered the samples from animals, environment and workers in all stages of broider production chain, and was further divided into 14 cgST types. Analysis using @RISK software revealed that the Spearman correlation coefficients for slaughterhouses and hatcheries were 0.54 and 0.26, respectively. These research findings are expected to comprehensively guide chicken production and provide effective strategies for preventing and controlling Salmonella contamination in the broiler production chain.","PeriodicalId":12214,"journal":{"name":"Fems Microbiology Letters","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144834671","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

Growth inhibition by ppc deletion is rescued by isocitrate dehydrogenase mutations in Escherichia coli. 大肠杆菌中异柠檬酸脱氢酶突变挽救了ppc缺失的生长抑制。

IF 2.2 4区生物学

Fems Microbiology Letters Pub Date : 2025-01-10 DOI: 10.1093/femsle/fnaf013

Yoshihiro Toya, Tatsumi Imada, Mai Ishibashi, Yuichi Kawamoto, Kinuka Isshiki, Atsushi Shibai, Chikara Furusawa, Hiroshi Shimizu

{"title":"Growth inhibition by ppc deletion is rescued by isocitrate dehydrogenase mutations in Escherichia coli.","authors":"Yoshihiro Toya, Tatsumi Imada, Mai Ishibashi, Yuichi Kawamoto, Kinuka Isshiki, Atsushi Shibai, Chikara Furusawa, Hiroshi Shimizu","doi":"10.1093/femsle/fnaf013","DOIUrl":"10.1093/femsle/fnaf013","url":null,"abstract":"Phosphoenolpyruvate carboxylase encoded by ppc catalyzes the anaplerotic reaction of oxaloacetate in the tricarboxylic acid (TCA) cycle in Escherichia coli. Deletion of ppc does not prevent the cells from replenishing oxaloacetate via the glyoxylate shunt, but the ppc-deletion strain almost did not grow on glucose. In the present study, we obtained evolved strains by deleting both ppc and mutS to increase the mutation rate and investigated the mechanisms for improving growth by analyzing the mutated genes. Genome resequencing revealed that the evolved strains have non-synonymous mutations in icd encoding isocitrate dehydrogenase (ICDH). The introduction of icd mutations rescued the growth defects caused by ppc deletion. ICDH activity was strongly reduced by the amino acid substitutions G205D or N232S. The evolved strains appeared to suppress the competitive pathway for increasing the glyoxylate shunt flux. In metabolic engineering, the deletion of iclR, which encodes a repressor of the aceBAK operon, has been used to activate the glyoxylate shunt. The growth rate of the ΔppcΔiclR strain slightly increased, but it was still much lower than that of the Δppc + icdG205D strains. This finding suggests that iclR deletion is not sufficient to enhance glyoxylate shunt flux and that inactivation of the competitive pathway by icd mutations is more effective.","PeriodicalId":12214,"journal":{"name":"Fems Microbiology Letters","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143052120","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

Contributions of hemolytic proteins in virulent Aeromonas hydrophila to motile Aeromonas septicemia disease of channel catfish (Ictalurus punctatus). 嗜水气单胞菌毒力溶血蛋白在海峡鲶鱼运动性气单胞菌败血症中的作用。

IF 2.2 4区生物学

Fems Microbiology Letters Pub Date : 2025-01-10 DOI: 10.1093/femsle/fnae108

Dunhua Zhang, Jun Feng, Yi Wang, Craig A Shoemaker, Allison A Wise, Benjamin H Beck

{"title":"Contributions of hemolytic proteins in virulent Aeromonas hydrophila to motile Aeromonas septicemia disease of channel catfish (Ictalurus punctatus).","authors":"Dunhua Zhang, Jun Feng, Yi Wang, Craig A Shoemaker, Allison A Wise, Benjamin H Beck","doi":"10.1093/femsle/fnae108","DOIUrl":"10.1093/femsle/fnae108","url":null,"abstract":"Hemolytic proteins are a major group of virulence factors in pathogenic Aeromonas hydrophila. Six genes encoding presumable hemolytic proteins were revealed from the genome of virulent A. hydrophila (vAh) that caused severe disease in channel catfish. The aim of this study was to assess the contribution of these hemolytic proteins to the virulence of this bacterium. Genes coding for following six proteins were investigated: aerolysin (Arl), 21-kDa hemolysin (Hly1), thermostable hemolysin (Hly2), phospholipase/lecithinase-related hemolysin (Hly3), membrane-associated hemolysin III (Hly4), and cytolysin-associated hemolysin (Hly5). Individual genes were deleted from the bacterium using CRISPR-Cas9 mediated methods. Assessment showed that deletion of Arl gene (Δarl) completely abolished hemolytic activity of this mutant while Δhly1-Δhly5 mutants had the same activity as the wild vAh. Extracellular proteins (ECPs) of the Δarl mutant caused significantly (p < 0.01) less cell death in vitro with viability increased by approximately 20%, compared to the wild vAh. ECPs of mutants Δhly1-Δhly5 remained the same cell toxicity as the wild vAh. A second deletion of hly5 from the Δarl mutant further lowered the cell toxicity of the ECP of the mutant (Δarl + Δhly5). Assays in vivo showed that both Δarl and Δhly5 mutants caused less fish mortality with reduction of 57% and 16%, respectively, compared to the wild vAh; the Δarl + Δhly5 mutant caused the least mortality with approximately 87% of reduction; and other mutants had the same virulence as the wild vAh. Analyses of SDS-PAGE (sodium dodecyl sulfate-polyacrylamide gel electrophoresis) and Western blotting evidently indicate that both Arl and Hly5 proteins formed hexamer-like stable structures post secretion from the bacterium. Arl and Hly5 apparently had synergistic action in cytotoxicity and causing disease and were the major virulence factors among the six hemolytic proteins analyzed in this study.","PeriodicalId":12214,"journal":{"name":"Fems Microbiology Letters","volume":" ","pages":""},"PeriodicalIF":2.2,"publicationDate":"2025-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142806554","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