Research in microbiology最新文献_第3页

MibR and LibR are involved in the transcriptional regulation of the ipdC gene in Azospirillum brasilense Sp7 MibR和LibR参与巴西氮螺旋菌Sp7中ipdC基因的转录调控。

IF 2.5 4区生物学

Research in microbiology Pub Date : 2025-07-01 DOI: 10.1016/j.resmic.2025.104295

Sandra R. Reyes-Carmona , Saúl Jijón Moreno , Alberto Ramírez-Mata , María Luisa Xiqui Vázquez , Beatriz Eugenia Baca

{"title":"MibR and LibR are involved in the transcriptional regulation of the ipdC gene in Azospirillum brasilense Sp7","authors":"Sandra R. Reyes-Carmona , Saúl Jijón Moreno , Alberto Ramírez-Mata , María Luisa Xiqui Vázquez , Beatriz Eugenia Baca","doi":"10.1016/j.resmic.2025.104295","DOIUrl":"10.1016/j.resmic.2025.104295","url":null,"abstract":"<div><div><em>Azospirillum brasilense</em> is a PGPR that produces the phytohormone IAA, a signaling molecule involved in bacteria-plant interaction processes. IAA biosynthesis in <em>Azospirillum</em> is mainly carried out via the IPyA pathway in which the enzyme phenylpyruvate decarboxylase encoded by the <em>ipdC</em> gene is the main. The promoter region of <em>ipdC</em> gene contains <em>cis</em> elements that are highly conserved among different <em>Azospirillum</em> strains. In this work, we identified two proteins that interact with the promoter region of the <em>ipdC</em> gene, named MibR and LibR that belong to the MarR and LuxR transcriptional regulators family, respectively. Both proteins have an HTH domain, and in the case of LibR, it has a REC domain, with aspartic acid residue conserved in positions 7, 8 and 54, this last as a possible phosphorylation target. To explore their participation in the regulation of the <em>ipdC</em> gene, mutants of <em>libR</em>, <em>mibR</em>, and <em>libR-mibR</em> double mutant were generated. The results showed a decrease in IAA biosynthesis that was related to the observed decrease in <em>ipdC</em> gene expression mostly in the doble mutant compared with the wild type. In this work we suggest that <em>ipdC</em> transcription is regulated by LibR and MibR, providing new findings insight into the mechanism employed by <em>A. brasilense</em> to control IAA biosynthesis.</div></div>","PeriodicalId":21098,"journal":{"name":"Research in microbiology","volume":"176 5","pages":"Article 104295"},"PeriodicalIF":2.5,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143701371","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

Antimicrobial resistance in coagulase negative staphylococci: Genome analysis and role of horizontal gene transfer 凝固酶阴性葡萄球菌的抗菌素耐药性：基因组分析和水平基因转移的作用。

IF 2.5 4区生物学

Research in microbiology Pub Date : 2025-07-01 DOI: 10.1016/j.resmic.2025.104298

Tansu Dündar, Fatma Köksal Çakırlar

{"title":"Antimicrobial resistance in coagulase negative staphylococci: Genome analysis and role of horizontal gene transfer","authors":"Tansu Dündar, Fatma Köksal Çakırlar","doi":"10.1016/j.resmic.2025.104298","DOIUrl":"10.1016/j.resmic.2025.104298","url":null,"abstract":"<div><div>Coagulase-negative staphylococci (CNS) are emerging as significant contributors to antimicrobial resistance, yet their genomic characteristics remain incompletely understood. This study presents a whole-genome analysis of 12 multidrug-resistant CNS strains (<em>Staphylococcus epidermidis, Staphylococcus haemolyticus, Staphylococcus hominis</em>) isolated from blood cultures, focusing on antimicrobial resistance genes, mobile genetic elements (MGEs), and horizontal gene transfer (HGT) mechanisms.</div><div>We identified 22 resistance genes conferring resistance to 11 antimicrobial classes, many of which were plasmid-associated. Notably, we report the first detection of the ISSha1 insertion sequence in <em>S. hominis</em>, along with novel resistance plasmids, including pGO1 and VRSAp in <em>S. haemolyticus</em> and pAMα1 in <em>S. hominis</em>. The identification of bacteriophage-derived sequences in <em>S. haemolyticus</em> and <em>S. hominis</em> suggests a role for phages in genetic exchange. CRISPR sequences and a Cas gene were detected in <em>S. hominis</em>, suggesting a potential but unconfirmed role in restricting gene transfer. Additionally, pGO1 was identified as a conjugative plasmid, while pAMα1 and VRSAp were determined to be mobilizable, reinforcing the role of CNS in resistance dissemination.</div><div>These results highlight CNS as reservoirs of antimicrobial resistance genes and emphasize the importance of species-specific genomic surveillance. Proactive monitoring of CNS is crucial for controlling antimicrobial resistance in clinical settings.</div></div>","PeriodicalId":21098,"journal":{"name":"Research in microbiology","volume":"176 5","pages":"Article 104298"},"PeriodicalIF":2.5,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143995795","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

Transposition of transposable element IS1 in Edwardsiella piscicida mutant generated by CRISPR/Cas9 along with λ-Red recombineering system CRISPR/Cas9和λ-Red重组系统在鱼腥爱德华菌突变体中的转座元件IS1的转座

IF 2.5 4区生物学

Research in microbiology Pub Date : 2025-07-01 DOI: 10.1016/j.resmic.2025.104297

Eun Gyeong Lee, Ki Hong Kim

{"title":"Transposition of transposable element IS1 in Edwardsiella piscicida mutant generated by CRISPR/Cas9 along with λ-Red recombineering system","authors":"Eun Gyeong Lee, Ki Hong Kim","doi":"10.1016/j.resmic.2025.104297","DOIUrl":"10.1016/j.resmic.2025.104297","url":null,"abstract":"<div><div>This study aimed to investigate unintended mutations introduced by the CRISPR/Cas9 genome editing system in <em>Edwardsiella piscicida</em>. Whole-genome sequencing was conducted on the wild-type <em>E. piscicida NH1</em> and its alanine racemase knockout mutants (<em>E. piscicida Δalr325 NH1</em> and <em>E. piscicida Δalr50 NH1</em>) generated using CRISPR/Cas9 with a λ-Red recombineering system. Comparative genomic analyses revealed that the insertion sequence 1 (IS1) transpositions occurred in the CRISPR/Cas9-edited mutants, disrupting the type I restriction-modification system subunit M gene, in addition to the targeted gene deletion. Interestingly, no IS1 transpositions were detected in mutants produced via conventional plasmid-based allelic exchange, indicating the potential link between CRISPR/Cas9-mediated editing and transposition events. These results suggest that genome editing via CRISPR/Cas9 could trigger IS1 transposition, potentially due to double-stranded DNA breaks. The lack of sequence similarity between the single guide RNA (sgRNA) and the transposed regions suggests that transpositions are not CRISPR/Cas9 off-target effects. This study provides evidence of interactions between mobile genetic elements and genome editing systems, requiring further investigation into their underlying mechanisms.</div></div>","PeriodicalId":21098,"journal":{"name":"Research in microbiology","volume":"176 5","pages":"Article 104297"},"PeriodicalIF":2.5,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143788846","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

In memoriam Julian Edmund Davies (1932–2025) 纪念朱利安·埃德蒙·戴维斯（1932-2025）。

IF 2.5 4区生物学

Research in microbiology Pub Date : 2025-07-01 DOI: 10.1016/j.resmic.2025.104302

Tarek Msadek

引用次数: 0

Highly specific virus-host linkages in mesothermophilic and circumneutral hot springs microbial communities. 中温和环中性温泉微生物群落的高度特异性病毒-宿主联系。

IF 2.5 4区生物学

Research in microbiology Pub Date : 2025-06-13 DOI: 10.1016/j.resmic.2025.104300

Oscar Salgado, Oscar Martínez, Yessica Rivas, Felipe Loyola-Ahumada

{"title":"Highly specific virus-host linkages in mesothermophilic and circumneutral hot springs microbial communities.","authors":"Oscar Salgado, Oscar Martínez, Yessica Rivas, Felipe Loyola-Ahumada","doi":"10.1016/j.resmic.2025.104300","DOIUrl":"10.1016/j.resmic.2025.104300","url":null,"abstract":"<p><p>Microbial communities in hot springs are distributed globally and have been extensively characterized regarding their diversity and composition. However, most studies have focused on cellular microbes, with relatively few addressing viruses, and even fewer examining virus-host ecology. Furthermore, research on viral communities and virus-host interactions has predominantly targeted extremely thermophilic environments, leaving mesothermophilic (40-80 °C) and circumneutral (pH 6-8) hot spring less explored. Here, we describe virus-host linkages using 37 metagenomic datasets obtained from 14 mesothermophilic and circumneutral hot springs. A parallel analysis of hot spring habitats-sediment, microbial mat, and water-employing diversity metrics, network analyses, and machine learning for virus-host pair identification revealed that viral communities appear to be more endemic than their hosts. Additionally, certain host taxa were identified as differentially abundant across habitats, some corresponding to specific hubs in the network analyses. Most viruses were linked to hosts within the same metagenome, with only a small fraction classified as cosmopolitan. Furthermore, nearly all virus-host pairs were exclusive to a single habitat type-sediment, microbial mat, or water. These findings suggests that virus-host linkages in mesothermophilic and circumneutral hot springs are highly specific, reflecting ecological adaptation within habitat niches.</p>","PeriodicalId":21098,"journal":{"name":"Research in microbiology","volume":" ","pages":"104300"},"PeriodicalIF":2.5,"publicationDate":"2025-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144302777","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

Exacerbation of virulence of multi-drug resistant Escherichia coli O104:H4 by subinhibitory concentrations of ampicillin 氨苄西林亚抑制浓度加重多重耐药大肠杆菌O104:H4的毒力。

IF 2.5 4区生物学

Research in microbiology Pub Date : 2025-03-01 DOI: 10.1016/j.resmic.2025.104266

Yaraymi Ortiz, Vianey Lechuga, Carolina Ortiz, Eduardo Palomino, Eduardo Franco, Norma Heredia, Santos García

{"title":"Exacerbation of virulence of multi-drug resistant Escherichia coli O104:H4 by subinhibitory concentrations of ampicillin","authors":"Yaraymi Ortiz, Vianey Lechuga, Carolina Ortiz, Eduardo Palomino, Eduardo Franco, Norma Heredia, Santos García","doi":"10.1016/j.resmic.2025.104266","DOIUrl":"10.1016/j.resmic.2025.104266","url":null,"abstract":"<div><div>Little is known about how subinhibitory concentrations of antibiotics to which bacteria are resistant affect bacterial virulence. In this study, the effect of subinhibitory concentrations of ampicillin on the virulence of <em>E. coli</em> O104:H4 was analyzed. Bacteria were pre-exposed to 0.1, 0.3, or 0.5 mg/mL of ampicillin in LB media and incubated for 4 h at 37 °C. Transformation capacity (using plasmids and PCR-amplified DNA sequences), swarming motility, biofilm production, curli formation, and virulence gene expression were determined. Ampicillin increased the transformation of <em>E. coli</em> O104:H4, with the highest number of transformants (>10<sup>4</sup> CFU/ng DNA; <em>p</em> ≤ 0.05) detected after exposure to DNA sequences of spectinomycin. In addition, bacteria pre-treated with 0.5 mg/mL of ampicillin exhibited higher swarming motility (7.6 cm, vs 6.0 cm for control; <em>p</em> ≤ 0.05) and biofilm production (up to 1.9-fold; <em>p</em> ≤ 0.05) when subsequently exposed to 0.1 and 0.3 mg/mL of antibiotic compared with the control. Also, significant overexpression of the virulence-related genes <em>flhC</em> (≤16.1-fold), <em>fliA</em> (≤22.1-fold), <em>csgA</em> (≤3.6-fold), <em>csgD</em> (≤9.1-fold), <em>stx2a</em> (≤32.2-fold), and the antibiotic resistance gene <em>blaTEM-1</em> (≤5.5-fold) was observed. In conclusion, ampicillin-resistant <em>E. coli</em> O104:H4 increased the expression of its virulence factors when exposed to most subinhibitory concentrations of ampicillin analyzed in this study.</div></div>","PeriodicalId":21098,"journal":{"name":"Research in microbiology","volume":"176 3","pages":"Article 104266"},"PeriodicalIF":2.5,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142966467","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

Cutibacterium acnes and its complex host interaction in prosthetic joint infection: Current insights and future directions 痤疮表皮杆菌及其复杂的宿主相互作用在假体关节感染：目前的见解和未来的方向。

IF 2.5 4区生物学

Research in microbiology Pub Date : 2025-03-01 DOI: 10.1016/j.resmic.2024.104265

Léa Thoraval , Jennifer Varin-Simon , Xavier Ohl , Frédéric Velard , Fany Reffuveille , Min Tang-Fichaux

引用次数: 0

Staphylococcus aureus: Dynamics of pathogenicity and antimicrobial-resistance in hospital and community environments - Comprehensive overview 金黄色葡萄球菌：医院和社区环境中致病性和抗菌药耐药性的动态 - 综合概述。

IF 2.5 4区生物学

Research in microbiology Pub Date : 2025-03-01 DOI: 10.1016/j.resmic.2025.104267

Giorgio Silva-Santana

引用次数: 0

Actinomycetes studies in Tunisia 突尼斯放线菌研究。

IF 2.5 4区生物学

Research in microbiology Pub Date : 2025-03-01 DOI: 10.1016/j.resmic.2025.104279

Souleima Dhahbi, Jeonghee Lee, Dohee Ryu, Ganiyu Akinniyi, Inho Yang

引用次数: 0

Characterization and identification of Pseudomonas sp. AW4, an arsenic-resistant and plant growth-promoting bacteria isolated from the soybean (Glycine max L.) rhizosphere 大豆（Glycine max L.）根际抗砷促进植物生长细菌Pseudomonas sp. AW4的鉴定与鉴定

IF 2.5 4区生物学

Research in microbiology Pub Date : 2025-03-01 DOI: 10.1016/j.resmic.2024.104263

Ana L. Wevar Oller , Gonzalo Torres Tejerizo , Paola P. Pereira , Romina del Pilar Pramparo , Elizabeth Agostini

{"title":"Characterization and identification of Pseudomonas sp. AW4, an arsenic-resistant and plant growth-promoting bacteria isolated from the soybean (Glycine max L.) rhizosphere","authors":"Ana L. Wevar Oller , Gonzalo Torres Tejerizo , Paola P. Pereira , Romina del Pilar Pramparo , Elizabeth Agostini","doi":"10.1016/j.resmic.2024.104263","DOIUrl":"10.1016/j.resmic.2024.104263","url":null,"abstract":"<div><div><em>Pseudomonas</em> sp. AW4 is a highly arsenic (As) resistant bacterium with plant growth promoting properties, originally isolated from the soybean (<em>Glycine</em> max L.) rhizosphere. In order to safely use this isolate in diverse bioformulations, its characterization needs to be completed and a reliable identification must be provided. In the present work, we analyzed the morpho-physiological, biochemical and genomic characteristics of <em>Pseudomonas</em> sp. AW4. Identification of the isolate varied according to the parameters analyzed, mainly biochemical and physiological tests or individual genes and phylogenetic analyses. In this regard, we performed massive sequencing of its genome, in order to consistently complete its characterization and identification. <em>Pseudomonas</em> sp. AW4 formed a monophyletic clade with <em>P. urmiensis</em> SWRI10, presenting 3.08 % of unique genes against this reference isolate. More than 70 % of AW4 genes were also shared with <em>P. oryziphila</em> strain 1257 NZ and with <em>P. reidholzensis</em> strain CCOS 865. The search for genes related to As resistance evidenced the presence of the operon <em>arsHRBC</em>. Taken together, results of the present work allow identification of this bacterium as <em>Pseudomonas urmiensis</em> AW4 and open up a number of opportunities to study this strain and understand the mechanisms of arsenic resistance and plant growth promotion.</div></div>","PeriodicalId":21098,"journal":{"name":"Research in microbiology","volume":"176 3","pages":"Article 104263"},"PeriodicalIF":2.5,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142795021","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