Research in microbiology最新文献_第3页

The influence of the phylum Planctomycetota in the environmental resistome Planctomycetota 门在环境抗性组中的影响。

IF 2.5 4区生物学

Research in microbiology Pub Date : 2024-07-01 DOI: 10.1016/j.resmic.2024.104196

Ofélia Godinho , Damien P. Devos , Sandra Quinteira , Olga M. Lage

引用次数: 0

Multiple SigB homologues govern the transcription of the ssgBp promoter in the sporulation–specific ssgB gene in Streptomyces coelicolor A3(2) 多个 SigB 同源物控制着 A3(2)链霉菌孢子特异性 ssgB 基因中 ssgBp 启动子的转录。

IF 2.5 4区生物学

Research in microbiology Pub Date : 2024-07-01 DOI: 10.1016/j.resmic.2024.104201

Rachel Javorova , Beatrica Sevcikova , Bronislava Rezuchova, Renata Novakova, Filip Opaterny, Dominika Csolleiova, Lubomira Feckova, Jan Kormanec

{"title":"Multiple SigB homologues govern the transcription of the ssgBp promoter in the sporulation–specific ssgB gene in Streptomyces coelicolor A3(2)","authors":"Rachel Javorova , Beatrica Sevcikova , Bronislava Rezuchova, Renata Novakova, Filip Opaterny, Dominika Csolleiova, Lubomira Feckova, Jan Kormanec","doi":"10.1016/j.resmic.2024.104201","DOIUrl":"10.1016/j.resmic.2024.104201","url":null,"abstract":"<div>Unlike Bacillus subtilis, Streptomyces coelicolor contains nine SigB homologues of the stress-response sigma factor SigB. By using a two-plasmid system, we previously identified promoters recognized by these sigma factors. Almost all promoters were recognized by several SigB homologues. However, no specific sequences of these promoters were found. One of these promoters, ssgBp, was selected to examine this cross-recognition in the native host. It controls the expression of the sporulation-specific gene ssgB. Using a luciferase reporter, the activity of this promoter in S. coelicolor and nine mutant strains lacking individual sigB homologous genes showed that sgBp is dependent on three sigma factors, SigH, SigN, and SigI. To determine which nucleotides in the-10 region are responsible for the selection of a specific SigB homologue, promoters mutated at the last three nucleotide positions were tested in the two-plasmid system. Some mutant promoters were specifically recognized by a distinct set of SigB homologues. Analysis of these mutant promoters in the native host showed the role of these nucleotides. A conserved nucleotide A at position 5 was essential for promoter activity, and two variable nucleotides at positions 4 and 6 were responsible for the partial selectivity of promoter recognition by SigB homologues.</div>","PeriodicalId":21098,"journal":{"name":"Research in microbiology","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140207491","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 and mutational analysis of the NurA protein from the hyperthermophilic euryarchaeon Thermococcus barophilus Ch5 超嗜热真菌嗜热球菌 Ch5 的 NurA 蛋白的生化特征和突变分析。

IF 2.5 4区生物学

Research in microbiology Pub Date : 2024-07-01 DOI: 10.1016/j.resmic.2024.104189

Guangyu Ma , Tan Lin , Peng Cao , Philippe Oger , Kunming Dong , Li Miao , Likui Zhang

{"title":"Biochemical characterization and mutational analysis of the NurA protein from the hyperthermophilic euryarchaeon Thermococcus barophilus Ch5","authors":"Guangyu Ma , Tan Lin , Peng Cao , Philippe Oger , Kunming Dong , Li Miao , Likui Zhang","doi":"10.1016/j.resmic.2024.104189","DOIUrl":"10.1016/j.resmic.2024.104189","url":null,"abstract":"<div>Archaeal NurA protein plays a key role in producing 3′-single stranded DNA used for homologous recombination repair, together with HerA, Mre11, and Rad50. Herein, we describe biochemical characteristics and roles of key amino acid residues of the NurA protein from the hyperthermophilic euryarchaeon Thermococcus barophilus Ch5 (Tba-NurA). Tba-NurA possesses 5′–3′ exonuclease activity for degrading DNA, displaying maximum efficiency at 45 °C–65 °C and at pH 8.0 in the presence of Mn2+. The thermostable Tba-NurA also possesses endonuclease activity capable of nicking plasmid DNA and circular ssDNA. Mutational data demonstrate that residue D49 of Tba-NurA is essential for exonuclease activity and is involved in binding ssDNA since the D49A mutant lacked exonuclease activity and reduced ssDNA binding. The R96A and R129A mutants had no detectable dsDNA binding, suggesting that residues R96 and R129 are important for binding dsDNA. The abolished degradation activity and reduced dsDNA binding of the D120A mutant suggest that residue D120 is essential for degradation activity and dsDNA binding. Additionally, residues Y392 and H400 are important for exonuclease activity since these mutations resulted in exonuclease activity loss. To our knowledge, it is the first report on biochemical characterization and mutational analysis of the NurA protein from Thermococcus.</div>","PeriodicalId":21098,"journal":{"name":"Research in microbiology","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139973333","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

Isolation of a PRD1-like phage uncovers the carriage of three putative conjugative plasmids in clinical Burkholderia contaminans 一种类似 PRD1 的噬菌体的分离发现了临床伯克霍尔德菌污染菌中携带的三种假定共轭质粒

IF 2.5 4区生物学

Research in microbiology Pub Date : 2024-07-01 DOI: 10.1016/j.resmic.2024.104202

Cassandra R. Stanton , Steve Petrovski , Steven Batinovic

{"title":"Isolation of a PRD1-like phage uncovers the carriage of three putative conjugative plasmids in clinical Burkholderia contaminans","authors":"Cassandra R. Stanton , Steve Petrovski , Steven Batinovic","doi":"10.1016/j.resmic.2024.104202","DOIUrl":"10.1016/j.resmic.2024.104202","url":null,"abstract":"<div>The Burkholderia cepacia complex (Bcc) is a group of increasingly multi-drug resistant opportunistic bacteria. This resistance is driven through a combination of intrinsic factors and the carriage of a broad range of conjugative plasmids harbouring virulence determinants. Therefore, novel treatments are required to treat and prevent further spread of these virulence determinants. In the search for phages infective for clinical Bcc isolates, CSP1 phage, a PRD1-like phage was isolated. CSP1 phage was found to require pilus machinery commonly encoded on conjugative plasmids to facilitate infection of Gram-negative bacteria genera including Escherichia and Pseudomonas. Whole genome sequencing and characterisation of one of the clinical Burkholderia isolates revealed it to be Burkholderia contaminans. B. contaminans 5080 was found to contain a genome of over 8 Mbp encoding multiple intrinsic resistance factors, such as efflux pump systems, but more interestingly, carried three novel plasmids encoding multiple putative virulence factors for increased host fitness, including antimicrobial resistance. Even though PRD1-like phages are broad host range, their use in novel antimicrobial treatments shouldn't be dismissed, as the dissemination potential of conjugative plasmids is extensive. Continued survey of clinical bacterial strains is also key to understanding the spread of antimicrobial resistance determinants and plasmid evolution.</div>","PeriodicalId":21098,"journal":{"name":"Research in microbiology","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0923250824000330/pdfft?md5=db2b5303bfc7ffe5081639e2734bdbd5&pid=1-s2.0-S0923250824000330-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140613764","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Whole genome analysis, thermal and UV-tolerance of Lactococcus phage BIM BV-114 isolated from cheese brine 从奶酪盐水中分离出的乳球菌噬菌体 BIM BV-114 的全基因组分析、耐热性和耐紫外线性。

IF 2.5 4区生物学

Research in microbiology Pub Date : 2024-07-01 DOI: 10.1016/j.resmic.2024.104203

Aliaksandra Herasimovich, Artur Akhremchuk, Leonid Valentovich, Anastasiya Sidarenka

{"title":"Whole genome analysis, thermal and UV-tolerance of Lactococcus phage BIM BV-114 isolated from cheese brine","authors":"Aliaksandra Herasimovich, Artur Akhremchuk, Leonid Valentovich, Anastasiya Sidarenka","doi":"10.1016/j.resmic.2024.104203","DOIUrl":"10.1016/j.resmic.2024.104203","url":null,"abstract":"<div>Lactococcus phages that belong to the genus Ceduovirus are among the three most frequently isolated phage groups infecting Lactococcus lactis starter strains in dairy plants. In this study, we characterized virulent Lactococcus phage BIM BV-114 isolated from industrial cheese brine in Belarus and identified as Ceduovirus. The bacteriophage demonstrated a relatively short lytic cycle (latent period of 23 ± 5 min, lysis time of 90 ± 5 min), high thermal stability (inactivation after 7 min at 95 °C in skimmed milk) and tolerance to UV radiation (inactivation time – 15 min), indicating adaptation for better persistence in dairy facilities. The genome of the phage BIM BV-114 (21 499 bp; 37 putative open reading frames) has a similar organization to that of other Ceduovirus phages. RLf1_00140 and RLf_00050 gene products, found in the early genes region, may be involved in the sensitivity of phage to the lactococcal abortive infection mechanisms AbiV and AbiQ, respectively. Furthermore, nucleotide deletion, observed in the middle region of the gene encoding putative tape measure protein (RLf1_00300), is possibly responsible for increased thermal tolerance of phage BIM BV-114. Together, these findings will contribute to a better knowledge of virulent Lactococcus phages and the development of effective methods of their control for dairy technologies.</div>","PeriodicalId":21098,"journal":{"name":"Research in microbiology","volume":null,"pages":null},"PeriodicalIF":2.5,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140857949","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

Protein kinase A regulatory subunit is required for normal growth, zoosporogenesis, and pathogenicity in Phytophthora sojae 大豆疫霉正常生长、动物孢子发生和致病性需要蛋白激酶A调控亚基。

IF 2.6 4区生物学

Research in microbiology Pub Date : 2024-05-01 DOI: 10.1016/j.resmic.2023.104152

Yunxiang Zhang , Zhuo Zhang , Yue Chen , Xinqiu Tan , Yong Liu , Zhe Tian , Jinglin Wang , Xin Zhang , Deyong Zhang

{"title":"Protein kinase A regulatory subunit is required for normal growth, zoosporogenesis, and pathogenicity in Phytophthora sojae","authors":"Yunxiang Zhang , Zhuo Zhang , Yue Chen , Xinqiu Tan , Yong Liu , Zhe Tian , Jinglin Wang , Xin Zhang , Deyong Zhang","doi":"10.1016/j.resmic.2023.104152","DOIUrl":"10.1016/j.resmic.2023.104152","url":null,"abstract":"<div>Phytophthora sojae, one of the most devastating Oomycete pathogens, causes severe diseases that lead to economic loss in the soybean industry. The production of zoospores play a crucial role during the development of Phytophthora disease. In this work, CRISPR/Cas9 genome editing technology were used to obtain protein kinase A regulatory subunit (PsPkaR) knockout mutants. The role of PsPkaR in the production of zoospores and pathogenicity of P. sojae was analyzed. The overall findings indicate that PsPkaR is involved in regulating the growth process of P. sojae, primarily affecting the hyphal morphology and growth rate. Additionally, PsPkaR participates in the regulation of the release process of zoospores. Specifically, knocking-out PsPkaR resulted in incomplete cytoplasmic differentiation and uneven protoplast division, leading to abnormal release of zoospores. Furthermore, when the PsPkaR knockout mutants were inoculated on soybean leaves, the pathogenicity was significantly reduced compared to that of the wild-type and control strains. These findings of this study provide important clues and evidence regarding the role of the cAMP-PKA signaling pathway in the interaction between P. sojae and its host. This work contributes to a better understanding of the pathogenic mechanism of P. sojae and the development of corresponding prevention and control strategies.</div>","PeriodicalId":21098,"journal":{"name":"Research in microbiology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89719387","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

Termitidicoccus mucosus gen. nov. sp. nov. a novel Verrucomicrobiota species isolated from Reticulitermes chinensis gives insights of high adaptability of symbiotic bacteria to termite gut ecosystem 从网纹蚁中分离出的新的白蚁微生物群（Termitidicoccus mucosus gen.

IF 2.6 4区生物学

Research in microbiology Pub Date : 2024-05-01 DOI: 10.1016/j.resmic.2023.104173

Cheng Mei , Yu Shi , Yu Wang , Zhengyong Qiu , Hong Yang

{"title":"Termitidicoccus mucosus gen. nov. sp. nov. a novel Verrucomicrobiota species isolated from Reticulitermes chinensis gives insights of high adaptability of symbiotic bacteria to termite gut ecosystem","authors":"Cheng Mei , Yu Shi , Yu Wang , Zhengyong Qiu , Hong Yang","doi":"10.1016/j.resmic.2023.104173","DOIUrl":"10.1016/j.resmic.2023.104173","url":null,"abstract":"<div>Verrucomicrobiota is widely distributed in various habitats including insect guts. It was found to be prevalent in almost all investigated termite guts, whereas their physiological functions are not very clear. In this study we characterized the physiological and genomic properties of Verrucomicrobiota strain TSB47T isolated from Reticulitermes chinensis. The cells of strain TSB47T were Gram-stain-negative, non-motile, and non-spore-forming coccoid with one or more warts. 16S rRNA gene analysis showed that the closest relatives of strain TSB47T were Opitutaceae strain TAV1 and Ereboglobus luteus Ho45T (98.3% and 95.4% sequence similarity, respectively). Whole genome analysis revealed that there are a large number of glycoside hydrolase genes, amino acid metabolism genes, complete Mo-Fe nitrogenase and Fe-Fe nitrogenase gene clusters, as well as cbb3-type cytochrome oxidase gene in the genome of strain TSB47T. Strain TSB47T grows well under anaerobic and microaerophilic conditions with a strong tolerance to oxygen. Physiological and genomic characters of strain TSB47T indicated its high adaptability to termite gut ecosystem. Based on phenotypic and phylogenetic evidence, we suggest strain TSB47T as the type species of a novel genus in the family Opitutaceae, for which the name Termitidicoccus mucosus sp. nov. is proposed. The type strain is TSB47T (CCTCC AB2022447T; KCTC 102044T).</div>","PeriodicalId":21098,"journal":{"name":"Research in microbiology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139061872","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 stringent response is strongly activated in the antibiotic producing strain, Streptomyces coelicolor 产生抗生素的菌株 Streptomyces coelicolor 强烈激活了严格反应。

IF 2.6 4区生物学

Research in microbiology Pub Date : 2024-05-01 DOI: 10.1016/j.resmic.2023.104177

Clara Lejeune , David Cornu , Laila Sago , Virginie Redeker , Marie-Joelle Virolle

{"title":"The stringent response is strongly activated in the antibiotic producing strain, Streptomyces coelicolor","authors":"Clara Lejeune , David Cornu , Laila Sago , Virginie Redeker , Marie-Joelle Virolle","doi":"10.1016/j.resmic.2023.104177","DOIUrl":"10.1016/j.resmic.2023.104177","url":null,"abstract":"<div>S. lividans and S. coelicolor are phylogenetically closely related strains with different abilities to produce the same specialized metabolites. Previous studies revealed that the strong antibiotic producer, S. coelicolor, had a lower ability to assimilate nitrogen and phosphate than the weak producer, Streptomyces lividans, and this resulted into a lower growth rate. A comparative proteomic dataset was used to establish the consequences of these nutritional stresses on the abundance of proteins of the translational apparatus of these strains, grown in low and high phosphate availability. Our study revealed that most proteins of the translational apparatus were less abundant in S. coelicolor than in S. lividans whereas it was the opposite for ET-Tu 3 and a TrmA-like methyltransferase. The expression of the latter being known to be under the positive control of the stringent response whereas that of the other ribosomal proteins is under its negative control, this indicated the occurrence of a strong activation of the stringent response in S. coelicolor. Furthermore, in S. lividans, ribosomal proteins were more abundant in phosphate proficiency than in phosphate limitation suggesting that a limitation in phosphate, that was also shown to trigger RelA expression, contributes to the induction of the stringent response.</div>","PeriodicalId":21098,"journal":{"name":"Research in microbiology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0923250823001547/pdfft?md5=88051488f17128fdd37532e9300b00d9&pid=1-s2.0-S0923250823001547-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139061838","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Elevated concentrations of polymyxin B elicit a biofilm-specific resistance mechanism in Vibrio cholerae 高浓度多粘菌素 B 在霍乱弧菌中激发生物膜特异性抗性机制

IF 2.6 4区生物学

Research in microbiology Pub Date : 2024-05-01 DOI: 10.1016/j.resmic.2023.104179

Julien Pauzé-Foixet, Annabelle Mathieu-Denoncourt, Marylise Duperthuy

{"title":"Elevated concentrations of polymyxin B elicit a biofilm-specific resistance mechanism in Vibrio cholerae","authors":"Julien Pauzé-Foixet, Annabelle Mathieu-Denoncourt, Marylise Duperthuy","doi":"10.1016/j.resmic.2023.104179","DOIUrl":"10.1016/j.resmic.2023.104179","url":null,"abstract":"<div>Vibrio cholerae can form biofilms in the aquatic environment and in the human intestine, facilitating the release of hyper-infectious aggregates. Due to the increasing antibiotic resistance, alternatives need to be found. One of these alternatives is antimicrobial peptides, including polymyxin B (PmB). In this study, we first investigated the resistance of V. cholerae O1 El Tor strain A1552 to various antimicrobials under aerobic and anaerobic conditions. An increased resistance to PmB is observed in anaerobiosis, with a 3-fold increase in the dose required for 50 % growth inhibition. We then studied the impact of the PmB on the formation and the degradation of V. cholerae biofilms to PmB. Our results show that PmB affects more efficiently biofilm formation under anaerobic conditions. On the other hand, preformed biofilms are susceptible to degradation by PmB at concentrations close to the minimal inhibitory concentration. At higher concentrations, we observe an opacification of the biofilm structures within 20 min post-treatment, suggesting a densification of the structure. This densification does not seem to result from the overexpression of matrix genes but rather from DNA release through massive cell lysis, likely forming a protective shield that limits the penetration of the PmB into the biofilm.</div>","PeriodicalId":21098,"journal":{"name":"Research in microbiology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139376179","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

Utilization of glycoprotein-derived N-acetylglucosamine-L-asparagine during Enterococcus faecalis infection depends on catabolic and transport enzymes of the glycosylasparaginase locus 粪肠球菌感染过程中对糖蛋白衍生的n-乙酰氨基葡萄糖- l -天冬酰胺的利用取决于糖基天冬酰胺酶位点的分解代谢和转运酶。

IF 2.6 4区生物学

Research in microbiology Pub Date : 2024-05-01 DOI: 10.1016/j.resmic.2023.104169

Victor Combret , Isabelle Rincé , Aurélie Budin-Verneuil , Cécile Muller , Josef Deutscher , Axel Hartke , Nicolas Sauvageot

{"title":"Utilization of glycoprotein-derived N-acetylglucosamine-L-asparagine during Enterococcus faecalis infection depends on catabolic and transport enzymes of the glycosylasparaginase locus","authors":"Victor Combret , Isabelle Rincé , Aurélie Budin-Verneuil , Cécile Muller , Josef Deutscher , Axel Hartke , Nicolas Sauvageot","doi":"10.1016/j.resmic.2023.104169","DOIUrl":"10.1016/j.resmic.2023.104169","url":null,"abstract":"<div>Enterococcus faecalis is a Gram-positive clinical pathogen causing severe infections. Its survival during infection depends on its ability to utilize host-derived metabolites, such as protein-deglycosylation products. We have identified in E. faecalis OG1RF a locus (ega) involved in the catabolism of the glycoamino acid N-acetylglucosamine-L-asparagine. This locus is separated into two transcription units, genes egaRP and egaGBCD1D2, respectively. RT-qPCR experiments revealed that the expression of the ega locus is regulated by the transcriptional repressor EgaR. Electromobility shift assays evidenced that N-acetylglucosamine-L-asparagine interacts directly with the EgaR protein, which leads to the transcription of the ega genes. Growth studies with egaG, egaB and egaC mutants confirmed that the encoded proteins are necessary for N-acetylglucosamine-L-asparagine catabolism. This glycoamino acid is transported and phosphorylated by a specific phosphotransferase system EIIABC components (OG1RF_10751, EgaB, EgaC) and subsequently hydrolyzed by the glycosylasparaginase EgaG, which generates aspartate and 6-P-N-acetyl-β-d-glucosaminylamine. The latter can be used as a fermentable carbon source by E. faecalis. Moreover, Galleria mellonella larvae had a significantly higher survival rate when infected with ega mutants compared to the wild-type strain, suggesting that the loss of N-acetylglucosamine-L-asparagine utilization affects enterococcal virulence.</div>","PeriodicalId":21098,"journal":{"name":"Research in microbiology","volume":null,"pages":null},"PeriodicalIF":2.6,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136398986","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