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":"<p><p>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 Yarrowia lipolytica 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 Y. lipolytica 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.</p>","PeriodicalId":21098,"journal":{"name":"Research in microbiology","volume":" ","pages":"104299"},"PeriodicalIF":2.5,"publicationDate":"2025-04-28","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}
{"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":"https://doi.org/10.1016/j.resmic.2025.104298","url":null,"abstract":"<p><p>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 (Staphylococcus epidermidis, Staphylococcus haemolyticus, Staphylococcus hominis) isolated from blood cultures, focusing on antimicrobial resistance genes, mobile genetic elements (MGEs), and horizontal gene transfer (HGT) mechanisms. 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 S. hominis, along with novel resistance plasmids, including pGO1 and VRSAp in S. haemolyticus and pAMα1 in S. hominis. The identification of bacteriophage-derived sequences in S. haemolyticus and S. hominis suggests a role for phages in genetic exchange. CRISPR sequences and a Cas gene were detected in S. hominis, 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. 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.</p>","PeriodicalId":21098,"journal":{"name":"Research in microbiology","volume":" ","pages":"104298"},"PeriodicalIF":2.5,"publicationDate":"2025-04-08","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}
{"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":"<p><p>This study aimed to investigate unintended mutations introduced by the CRISPR/Cas9 genome editing system in Edwardsiella piscicida. Whole-genome sequencing was conducted on the wild-type E. piscicida NH1 and its alanine racemase knockout mutants (E. piscicida Δalr325 NH1 and E. piscicida Δalr50 NH1) 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.</p>","PeriodicalId":21098,"journal":{"name":"Research in microbiology","volume":" ","pages":"104297"},"PeriodicalIF":2.5,"publicationDate":"2025-04-02","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}
Hopeful Tusalifye Kanthenga, Riza Jane S Banicod, Wilson Ntege, Moses Njeru Njiru, Aqib Javaid, Nazia Tabassum, Young-Mog Kim, Fazlurrahman Khan
{"title":"Functional diversity of AI-2/LuxS system in lactic acid bacteria: Impacts on biofilm formation and environmental resilience.","authors":"Hopeful Tusalifye Kanthenga, Riza Jane S Banicod, Wilson Ntege, Moses Njeru Njiru, Aqib Javaid, Nazia Tabassum, Young-Mog Kim, Fazlurrahman Khan","doi":"10.1016/j.resmic.2025.104296","DOIUrl":"10.1016/j.resmic.2025.104296","url":null,"abstract":"<p><p>A key component of microbial communication, autoinducer-2 (AI-2) signaling, affects several physiological processes, including environmental adaptation and biofilm formation in lactic acid bacteria (LAB). The multifarious contribution of AI-2, synthesized by LuxS, in improving biofilms and tolerance to hostile conditions in LAB has been investigated in this review. The evolutionary conservation and diversity of AI-2 are shown by a phylogenetic analysis of luxS gene among several LAB species. Furthermore, AI-2 signaling in LAB improves resistance to unfavorable environmental factors, including pH fluctuations, temperature extremes, and antimicrobial agents. Lactic acid bacteria could set off defenses against harmful impacts from environmental stresses.</p>","PeriodicalId":21098,"journal":{"name":"Research in microbiology","volume":" ","pages":"104296"},"PeriodicalIF":2.5,"publicationDate":"2025-03-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143693125","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}
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":"<p><p>Azospirillum brasilense is a PGPR that produces the phytohormone IAA, a signaling molecule involved in bacteria-plant interaction processes. IAA biosynthesis in Azospirillum is mainly carried out via the IPyA pathway in which the enzyme phenylpyruvate decarboxylase encoded by the ipdC gene is the main. The promoter region of ipdC gene contains cis elements that are highly conserved among different Azospirillum strains. In this work, we identified two proteins that interact with the promoter region of the ipdC 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 ipdC gene, mutants of libR, mibR, and libR-mibR double mutant were generated. The results showed a decrease in IAA biosynthesis that was related to the observed decrease in ipdC gene expression mostly in the doble mutant compared with the wild type. In this work we suggest that ipdC transcription is regulated by LibR and MibR, providing new findings insight into the mechanism employed by A. brasilense to control IAA biosynthesis.</p>","PeriodicalId":21098,"journal":{"name":"Research in microbiology","volume":" ","pages":"104295"},"PeriodicalIF":2.5,"publicationDate":"2025-03-22","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}
{"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}
Léa Thoraval , Jennifer Varin-Simon , Xavier Ohl , Frédéric Velard , Fany Reffuveille , Min Tang-Fichaux
{"title":"Cutibacterium acnes and its complex host interaction in prosthetic joint infection: Current insights and future directions","authors":"Léa Thoraval , Jennifer Varin-Simon , Xavier Ohl , Frédéric Velard , Fany Reffuveille , Min Tang-Fichaux","doi":"10.1016/j.resmic.2024.104265","DOIUrl":"10.1016/j.resmic.2024.104265","url":null,"abstract":"<div><div><em>Cutibacterium acnes</em> is a commensal Gram-positive anaerobic bacterium that can also act as an opportunistic pathogen in various diseases, particularly in prosthetic joint infections (PJI). Throughout this review, we delve into the current understanding of the intricate interactions between <em>C. acnes</em> and host cells and discuss bacterial persistence in the host. <em>C. acnes</em> colonization and subsequent PJI set-up represent complex processes involving bacterial adhesion, immune recognition, and host response mechanisms. We highlight existing knowledge and gaps in specific host-pathogen interactions and stress the importance of acquiring additional information to develop targeted strategies for preventing and treating <em>C. acnes</em>-related PIJ.</div></div>","PeriodicalId":21098,"journal":{"name":"Research in microbiology","volume":"176 3","pages":"Article 104265"},"PeriodicalIF":2.5,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142865475","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}
{"title":"Staphylococcus aureus: Dynamics of pathogenicity and antimicrobial-resistance in hospital and community environments - Comprehensive overview","authors":"Giorgio Silva-Santana","doi":"10.1016/j.resmic.2025.104267","DOIUrl":"10.1016/j.resmic.2025.104267","url":null,"abstract":"<div><div>This study reviews <em>Staphylococcus aureus</em>, a significant pathogen in both hospital and community-acquired infections, addressing its epidemiology, pathogenesis, and antimicrobial resistance. It highlights virulence mechanisms, such as adhesion factors, toxins, enzymes, and biofilms, which contribute to survival and immune evasion. The spread of resistance occurs through the transfer of mobile genetic elements like SCC<em>mec</em> and genetic mutations. The analysis also compares hospital and community strains, including multidrug-resistant lineages like MRSA, VISA, and VRSA. The study concludes that <em>S. aureus</em> presents a major public health challenge, requiring new therapeutic approaches and preventive strategies.</div></div>","PeriodicalId":21098,"journal":{"name":"Research in microbiology","volume":"176 3","pages":"Article 104267"},"PeriodicalIF":2.5,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142979843","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}
Souleima Dhahbi, Jeonghee Lee, Dohee Ryu, Ganiyu Akinniyi, Inho Yang
{"title":"Actinomycetes studies in Tunisia","authors":"Souleima Dhahbi, Jeonghee Lee, Dohee Ryu, Ganiyu Akinniyi, Inho Yang","doi":"10.1016/j.resmic.2025.104279","DOIUrl":"10.1016/j.resmic.2025.104279","url":null,"abstract":"<div><div>Tunisia, located in North Africa, has a diverse topography along the Mediterranean Sea to the Sahara Desert. These environments encompass oases, rhizosphere soils, desert deposits, saline wetlands, offshore oilrigs, and ancient monument rocks. The country's varied environments have led to the isolation of a multitude of actinomycetes. A phylogenetic analysis based on the 16S rRNA sequences of one hundred isolated actinomycetes strains revealed that the majority belong to the genus <em>Streptomyces</em>. Secondary metabolite studies from these actinomycetes yielded 33 natural products. Notably, compound <strong>12</strong>, 3-<em>O</em>-methylviridicatin, exhibited antitumor activity and suppressed HIV expression. This showcases Tunisia's potential for natural product research.</div></div>","PeriodicalId":21098,"journal":{"name":"Research in microbiology","volume":"176 3","pages":"Article 104279"},"PeriodicalIF":2.5,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143010809","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}
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}