Pub Date : 2024-09-25eCollection Date: 2024-01-01DOI: 10.3389/fmicb.2024.1408521
Aisha Umar, Mohamed S Elshikh, Reem M Aljowaie, Juma Mahmud Hussein, Laurent Dufossé, Chenghong Wu, Junxing Lu
Ganoderma, a well-known genus in the Ganodermataceae family, has caused the extinction of several tree species due to its pathogenicity. This study explored the pathogenic effect of a newly identified Ganoderma species on trees and its competitive efficiency against Trichoderma species. Ganoderma camelum sp. nov. is characterized by small sessile basidiomata and a velvety, soft, camel-brown pileus. Phylogenetic analysis and ITS rDNA sequences indicated that the species were Trichoderma and Ganoderma camelum. Both fungal species competed antagonistically by secreting laccase. The laccase activity of G. camelum, with a value of 8.3 ± 4.0 U/mL, demonstrated the highest competitive activity against Trichoderma species. The laccase produced by T. atroviride (2.62 U/mL) was most effective in countering the pathogenic action of the novel G. camelum. The molecular weights of laccase were determined using SDS-PAGE (62.0 kDa for G. camelum and 57.0 kDa for T. atroviride). Due to the white rot induced by this Ganoderma species in the host tree, G. camelum showed the highest percentage inhibition of radial growth (76.3%) compared to T. atroviride (28.7%). This study aimed to evaluate the competitive antagonistic activity of Ganoderma and Trichoderma on malt extract agar media in the context of white rot disease in the host tree. This study concluded that the laccase from G. camelum caused weight loss in rubber wood blocks through laccase action, indicating tissue injury in the host species. Therefore, it was also concluded that G. camelum was more effective in pathogenic action of the host and resisted the biological action of T. atroviride. In principal components analysis (PCA), all the species associated with laccase exhibited a very strong influence on the variability of the system. The PIRG rate (percentage inhibition of radial growth) was strongly and positively correlated with laccase activity.
{"title":"Competitive antagonistic action of laccase between <i>Trichoderma</i> species and the newly identified wood pathogenic <i>Ganoderma camelum</i>.","authors":"Aisha Umar, Mohamed S Elshikh, Reem M Aljowaie, Juma Mahmud Hussein, Laurent Dufossé, Chenghong Wu, Junxing Lu","doi":"10.3389/fmicb.2024.1408521","DOIUrl":"10.3389/fmicb.2024.1408521","url":null,"abstract":"<p><p><i>Ganoderma</i>, a well-known genus in the Ganodermataceae family, has caused the extinction of several tree species due to its pathogenicity. This study explored the pathogenic effect of a newly identified <i>Ganoderma</i> species on trees and its competitive efficiency against <i>Trichoderma</i> species. <i>Ganoderma camelum</i> sp. nov. is characterized by small sessile basidiomata and a velvety, soft, camel-brown pileus. Phylogenetic analysis and ITS rDNA sequences indicated that the species were <i>Trichoderma</i> and <i>Ganoderma camelum</i>. Both fungal species competed antagonistically by secreting laccase. The laccase activity of <i>G. camelum</i>, with a value of 8.3 ± 4.0 U/mL, demonstrated the highest competitive activity against <i>Trichoderma</i> species. The laccase produced by <i>T. atroviride</i> (2.62 U/mL) was most effective in countering the pathogenic action of the novel <i>G. camelum</i>. The molecular weights of laccase were determined using SDS-PAGE (62.0 kDa for <i>G. camelum</i> and 57.0 kDa for <i>T. atroviride</i>). Due to the white rot induced by this <i>Ganoderma</i> species in the host tree, <i>G. camelum</i> showed the highest percentage inhibition of radial growth (76.3%) compared to <i>T. atroviride</i> (28.7%). This study aimed to evaluate the competitive antagonistic activity of <i>Ganoderma</i> and <i>Trichoderma</i> on malt extract agar media in the context of white rot disease in the host tree. This study concluded that the laccase from <i>G. camelum</i> caused weight loss in rubber wood blocks through laccase action, indicating tissue injury in the host species. Therefore, it was also concluded that <i>G. camelum</i> was more effective in pathogenic action of the host and resisted the biological action of <i>T. atroviride</i>. In principal components analysis (PCA), all the species associated with laccase exhibited a very strong influence on the variability of the system. The PIRG rate (percentage inhibition of radial growth) was strongly and positively correlated with laccase activity.</p>","PeriodicalId":12466,"journal":{"name":"Frontiers in Microbiology","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11461316/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142389384","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Laminitis is a serious health condition that can cause severe pain and lameness in horses. Due to lack of understanding of laminitis, treatments often fail to achieve the desired results. In recent years, we have begun to recognize that laminitis may involve a complex interaction between local and systemic inflammation. Dysbiosis of the gut microbiota has been linked in the development of systemic inflammation, and our previous findings suggest that the development of laminitis is closely linked to the production of harmful metabolites of the gut microbiota. In addition, it was found that localized lesions in the hoof, especially lamellar injuries, are the most direct cause of laminitis. Matrix metalloproteinases have been found to be strongly associated with the development of laminitis. Recent discovery has found that methylated tirilazad has a role in repairing laminar tissue in vitro. However, its efficacy in horses never has been studied. Therefore, we aimed to investigate the efficacy of methylated tirilazad (product name: PTP-102) in the prevention/treatment of oligofructose-induced laminitis. The results showed that oligofructose successfully induced laminitis in horses, resulting in detreated clinical signs. Blood indices (including inflammation-related indices and other related indices) were significantly increased. Observations of dissection and staining showed significant bleeding, swelling, and damage to hoof tissue. Analysis of the gut microbiota showed a significant decrease in abundance and diversity, and a significant increase in the relative abundance of specific bacteria. Following methylated tirilazad intervention, there were a significant improvement in clinical signs, blood markers and lamellar tissue damage. Additionally, methylated tirilazad positively influenced the gut microbiota structure by reducing the relative abundance of genera closely associated with the development of equine laminitis. This suggests that some of the therapeutic mechanism of methylated tirilazad may be linked to its effects on the gut microbiota. Notably, methylated tirilazad had better effect in the treatment group than the prophylactic group, indicating the post-diagnosis utility of methylated tirilazad for laminitis management.
{"title":"Methylated tirilazad may mitigate oligofructose-induced laminitis in horses.","authors":"Maimaiti Tuniyazi, Ruibo Tang, Xiaoyu Hu, Naisheng Zhang","doi":"10.3389/fmicb.2024.1391892","DOIUrl":"10.3389/fmicb.2024.1391892","url":null,"abstract":"<p><p>Laminitis is a serious health condition that can cause severe pain and lameness in horses. Due to lack of understanding of laminitis, treatments often fail to achieve the desired results. In recent years, we have begun to recognize that laminitis may involve a complex interaction between local and systemic inflammation. Dysbiosis of the gut microbiota has been linked in the development of systemic inflammation, and our previous findings suggest that the development of laminitis is closely linked to the production of harmful metabolites of the gut microbiota. In addition, it was found that localized lesions in the hoof, especially lamellar injuries, are the most direct cause of laminitis. Matrix metalloproteinases have been found to be strongly associated with the development of laminitis. Recent discovery has found that methylated tirilazad has a role in repairing laminar tissue <i>in vitro</i>. However, its efficacy in horses never has been studied. Therefore, we aimed to investigate the efficacy of methylated tirilazad (product name: PTP-102) in the prevention/treatment of oligofructose-induced laminitis. The results showed that oligofructose successfully induced laminitis in horses, resulting in detreated clinical signs. Blood indices (including inflammation-related indices and other related indices) were significantly increased. Observations of dissection and staining showed significant bleeding, swelling, and damage to hoof tissue. Analysis of the gut microbiota showed a significant decrease in abundance and diversity, and a significant increase in the relative abundance of specific bacteria. Following methylated tirilazad intervention, there were a significant improvement in clinical signs, blood markers and lamellar tissue damage. Additionally, methylated tirilazad positively influenced the gut microbiota structure by reducing the relative abundance of genera closely associated with the development of equine laminitis. This suggests that some of the therapeutic mechanism of methylated tirilazad may be linked to its effects on the gut microbiota. Notably, methylated tirilazad had better effect in the treatment group than the prophylactic group, indicating the post-diagnosis utility of methylated tirilazad for laminitis management.</p>","PeriodicalId":12466,"journal":{"name":"Frontiers in Microbiology","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11461245/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142389401","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Introduction: Plants are inherently connected with the microbiome, which plays a crucial role in regulating various host plant biological processes, including immunity, nutrient acquisition, and resistance against abiotic and biotic stresses. Many factors affect the interaction between plants and microbiome.
Methods and results: In this study, microbiome samples were collected from five niches (bulk soil, rhizoplane, root endosphere, phylloplane, and leaf endosphere) across four developmental stages (seedling, flowering, podding, and maturity) of various soybean varieties. Composition and structure of bacterial and fungal communities were analyzed using 16S rRNA gene and ITS (Internally Transcribed Spacer) region amplicon sequencing. It was observed that both niches and developmental stages significantly impact on the assembly and composition of soybean microbiome. However, variety, presence of a transgene, and glyphosate application had minimal effects on microbial communities. The dominant microbiome varied across the five niches, with most containing beneficial microbial communities capable of promoting plant growth or increasing disease resistance. Types and abundance of the dominant microbes affected network stability, potentially resulting in functional changes in different ecological niches.
Conclusion: This study provides theoretical evidence for microbial protection of plants against diseases and demonstrates that systematic analysis of the composition and diversity of soybean microbiomes can contribute to the development of biological control technologies.
{"title":"The response of microbiome assembly within different niches across four stages to the cultivation of glyphosate-tolerant and conventional soybean varieties.","authors":"Shengqian Chao, Yu Sun, Yin Zhang, Yifan Chen, Lili Song, Peng Li, Xueming Tang, Jingang Liang, Beibei Lv","doi":"10.3389/fmicb.2024.1439735","DOIUrl":"10.3389/fmicb.2024.1439735","url":null,"abstract":"<p><strong>Introduction: </strong>Plants are inherently connected with the microbiome, which plays a crucial role in regulating various host plant biological processes, including immunity, nutrient acquisition, and resistance against abiotic and biotic stresses. Many factors affect the interaction between plants and microbiome.</p><p><strong>Methods and results: </strong>In this study, microbiome samples were collected from five niches (bulk soil, rhizoplane, root endosphere, phylloplane, and leaf endosphere) across four developmental stages (seedling, flowering, podding, and maturity) of various soybean varieties. Composition and structure of bacterial and fungal communities were analyzed using 16S rRNA gene and ITS (Internally Transcribed Spacer) region amplicon sequencing. It was observed that both niches and developmental stages significantly impact on the assembly and composition of soybean microbiome. However, variety, presence of a transgene, and glyphosate application had minimal effects on microbial communities. The dominant microbiome varied across the five niches, with most containing beneficial microbial communities capable of promoting plant growth or increasing disease resistance. Types and abundance of the dominant microbes affected network stability, potentially resulting in functional changes in different ecological niches.</p><p><strong>Conclusion: </strong>This study provides theoretical evidence for microbial protection of plants against diseases and demonstrates that systematic analysis of the composition and diversity of soybean microbiomes can contribute to the development of biological control technologies.</p>","PeriodicalId":12466,"journal":{"name":"Frontiers in Microbiology","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11461410/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142389420","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-25eCollection Date: 2024-01-01DOI: 10.3389/fmicb.2024.1484069
Megha Prasad, Ajith Madhavan, Pradeesh Babu, Amrita Salim, Suja Subhash, Bipin G Nair, Sanjay Pal
Arsenic contamination of soil and water is a major environmental issue. Bioremediation through plant growth-promoting bacteria is viable, cost-effective, and sustainable. Along with arsenic removal, it also improves plant productivity under stressful conditions. A crucial aspect of such a strategy is the selection of bacterial inoculum. The described study demonstrates that the indigenous wastewater isolate, ASBT-KP1, could be a promising candidate. Identified as Klebsiella pneumoniae, ASBT-KP1 harbors genes associated with heavy metal and oxidative stress resistance, production of antimicrobial compounds and growth-promotion activity. The isolate efficiently accumulated 30 μg/g bacterial dry mass of arsenic. Tolerance toward arsenate and arsenite was 120 mM and 70 mM, respectively. Plant biomass content of Vigna radiata improved by 13% when grown in arsenic-free soil under laboratory conditions in the presence of the isolate. The increase became even more significant under the same conditions in the presence of arsenic, recording a 37% increase. The phylogenetic analysis assigned ASBT-KP1 to the clade of Klebsiella strains that promote plant growth. Similar results were also observed in Oryza sativa, employed to assess the ability of the strain to promote growth, in plants other than V. radiata. This study identifies a prospective candidate in ASBT-KP1 that could be employed as a plant growth-promoting rhizoinoculant in agricultural practices.
{"title":"Alleviating arsenic stress affecting the growth of <i>Vigna radiata</i> through the application of <i>Klebsiella</i> strain ASBT-KP1 isolated from wastewater.","authors":"Megha Prasad, Ajith Madhavan, Pradeesh Babu, Amrita Salim, Suja Subhash, Bipin G Nair, Sanjay Pal","doi":"10.3389/fmicb.2024.1484069","DOIUrl":"10.3389/fmicb.2024.1484069","url":null,"abstract":"<p><p>Arsenic contamination of soil and water is a major environmental issue. Bioremediation through plant growth-promoting bacteria is viable, cost-effective, and sustainable. Along with arsenic removal, it also improves plant productivity under stressful conditions. A crucial aspect of such a strategy is the selection of bacterial inoculum. The described study demonstrates that the indigenous wastewater isolate, ASBT-KP1, could be a promising candidate. Identified as <i>Klebsiella pneumoniae</i>, ASBT-KP1 harbors genes associated with heavy metal and oxidative stress resistance, production of antimicrobial compounds and growth-promotion activity. The isolate efficiently accumulated 30 μg/g bacterial dry mass of arsenic. Tolerance toward arsenate and arsenite was 120 mM and 70 mM, respectively. Plant biomass content of <i>Vigna radiata</i> improved by 13% when grown in arsenic-free soil under laboratory conditions in the presence of the isolate. The increase became even more significant under the same conditions in the presence of arsenic, recording a 37% increase. The phylogenetic analysis assigned ASBT-KP1 to the clade of <i>Klebsiella</i> strains that promote plant growth. Similar results were also observed in <i>Oryza sativa</i>, employed to assess the ability of the strain to promote growth, in plants other than <i>V. radiata.</i> This study identifies a prospective candidate in ASBT-KP1 that could be employed as a plant growth-promoting rhizoinoculant in agricultural practices.</p>","PeriodicalId":12466,"journal":{"name":"Frontiers in Microbiology","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11461332/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142389365","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-25eCollection Date: 2024-01-01DOI: 10.3389/fmicb.2024.1463441
Janani Madhuravasal Krishnan, Krishna M Roskin, Heidi L Meeds, Jason T Blackard
Introduction: Illicit drug use, particularly the synthetic opioid fentanyl, presents a significant global health challenge. Previous studies have shown that fentanyl enhances viral replication; yet, the mechanisms by which it affects HIV pathogenesis remain unclear. This study investigated the impact of fentanyl on HIV replication in CD4+ T lymphocytes.
Methods: CD4+ T lymphocytes from HIV-negative donors were activated, infected with HIVNL4-3, and treated with fentanyl. HIV proviral DNA and p24 antigen expression were quantified using real-time PCR and ELISA, respectively. Single-cell RNA libraries were analyzed to identify differentially expressed genes.
Results: Results indicated that fentanyl treatment increased HIV p24 expression and proviral DNA levels, and naltrexone mitigated these effects. Single-cell RNAseq analysis identified significantly altered gene expression in CD4+ T lymphocytes.
Discussion: The results of our findings suggest that fentanyl promotes HIV replication ex vivo, emphasizing the need for a deeper understanding of opioid-virus interactions to develop better treatment strategies for individuals with HIV and opioid use disorder.
导言:非法使用毒品,尤其是合成阿片类药物芬太尼,对全球健康构成了重大挑战。以前的研究表明,芬太尼能增强病毒复制;然而,芬太尼影响艾滋病发病机制的机制仍不清楚。本研究调查了芬太尼对 CD4+ T 淋巴细胞中 HIV 复制的影响:方法:激活 HIV 阴性供体的 CD4+ T 淋巴细胞,用 HIVNL4-3 感染,并用芬太尼处理。分别使用实时 PCR 和酶联免疫吸附法对 HIV proviral DNA 和 p24 抗原表达进行量化。对单细胞 RNA 文库进行分析,以确定差异表达基因:结果表明,芬太尼治疗会增加 HIV p24 的表达和病毒 DNA 的水平,而纳曲酮可以减轻这些影响。单细胞 RNAseq 分析发现 CD4+ T 淋巴细胞中的基因表达发生了显著变化:讨论:我们的研究结果表明,芬太尼会促进体内艾滋病病毒的复制,这强调了深入了解阿片类药物与病毒之间相互作用的必要性,从而为艾滋病病毒感染者和阿片类药物使用障碍患者制定更好的治疗策略。
{"title":"Effect of fentanyl on HIV expression in peripheral blood mononuclear cells.","authors":"Janani Madhuravasal Krishnan, Krishna M Roskin, Heidi L Meeds, Jason T Blackard","doi":"10.3389/fmicb.2024.1463441","DOIUrl":"10.3389/fmicb.2024.1463441","url":null,"abstract":"<p><strong>Introduction: </strong>Illicit drug use, particularly the synthetic opioid fentanyl, presents a significant global health challenge. Previous studies have shown that fentanyl enhances viral replication; yet, the mechanisms by which it affects HIV pathogenesis remain unclear. This study investigated the impact of fentanyl on HIV replication in CD4<sup>+</sup> T lymphocytes.</p><p><strong>Methods: </strong>CD4<sup>+</sup> T lymphocytes from HIV-negative donors were activated, infected with HIV<sub>NL4-3</sub>, and treated with fentanyl. HIV proviral DNA and p24 antigen expression were quantified using real-time PCR and ELISA, respectively. Single-cell RNA libraries were analyzed to identify differentially expressed genes.</p><p><strong>Results: </strong>Results indicated that fentanyl treatment increased HIV p24 expression and proviral DNA levels, and naltrexone mitigated these effects. Single-cell RNAseq analysis identified significantly altered gene expression in CD4<sup>+</sup> T lymphocytes.</p><p><strong>Discussion: </strong>The results of our findings suggest that fentanyl promotes HIV replication <i>ex vivo</i>, emphasizing the need for a deeper understanding of opioid-virus interactions to develop better treatment strategies for individuals with HIV and opioid use disorder.</p>","PeriodicalId":12466,"journal":{"name":"Frontiers in Microbiology","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11461324/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142389387","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-25eCollection Date: 2024-01-01DOI: 10.3389/fmicb.2024.1462696
Maryam Abidizadegan, Elina Peltomaa, Polina Ilina, Päivi Tammela, Jaanika Blomster
Cryptophytes are a promising source of bioactive compounds that have not been fully explored. This research investigated the antimicrobial activity of total phenolic compounds (TPC) and exopolysaccharides (EPS) extracted from several cryptophytes against a range of harmful foodborne bacteria and fungi. To measure the minimum inhibitory concentration (MIC) value, the broth microdilution method was used. In the antibacterial evaluation of TPC, the MIC ranged between 31.25 and 500 μg/mL, while for the antifungal activity test, it varied from 31.25 to 125 μg/mL. In the antibacterial activity test of EPS, the MIC values ranged from 125 to 1,000 μg/mL, whereas in the antifungal susceptibility test, it ranged between 62.5 and 1,000 μg/mL. The most resistant pathogen against TPC was Escherichia coli, while Campylobacter jejuni was the most susceptible. In the case of EPS, the most resistant pathogen was Salmonella Typhimurium, while Aspergillus versicolor exhibited the highest susceptibility. Overall, in terms of antimicrobial activity, TPC was more effective than EPS. Finally, the tolerance level (TL) for TPC and EPS was ≤4 in all tested samples, indicating their bactericidal/fungicidal mechanism of action. In conclusion, TPC and EPS isolated from cryptophytes demonstrated remarkable antimicrobial properties and ability to fully eradicate pathogens, and could be considered as natural preservatives in the food industry.
{"title":"Cryptophytes as potential source of natural antimicrobials for food preservation.","authors":"Maryam Abidizadegan, Elina Peltomaa, Polina Ilina, Päivi Tammela, Jaanika Blomster","doi":"10.3389/fmicb.2024.1462696","DOIUrl":"10.3389/fmicb.2024.1462696","url":null,"abstract":"<p><p>Cryptophytes are a promising source of bioactive compounds that have not been fully explored. This research investigated the antimicrobial activity of total phenolic compounds (TPC) and exopolysaccharides (EPS) extracted from several cryptophytes against a range of harmful foodborne bacteria and fungi. To measure the minimum inhibitory concentration (MIC) value, the broth microdilution method was used. In the antibacterial evaluation of TPC, the MIC ranged between 31.25 and 500 μg/mL, while for the antifungal activity test, it varied from 31.25 to 125 μg/mL. In the antibacterial activity test of EPS, the MIC values ranged from 125 to 1,000 μg/mL, whereas in the antifungal susceptibility test, it ranged between 62.5 and 1,000 μg/mL. The most resistant pathogen against TPC was <i>Escherichia coli</i>, while <i>Campylobacter jejuni</i> was the most susceptible. In the case of EPS, the most resistant pathogen was <i>Salmonella</i> Typhimurium, while <i>Aspergillus versicolor</i> exhibited the highest susceptibility. Overall, in terms of antimicrobial activity, TPC was more effective than EPS. Finally, the tolerance level (TL) for TPC and EPS was ≤4 in all tested samples, indicating their bactericidal/fungicidal mechanism of action. In conclusion, TPC and EPS isolated from cryptophytes demonstrated remarkable antimicrobial properties and ability to fully eradicate pathogens, and could be considered as natural preservatives in the food industry.</p>","PeriodicalId":12466,"journal":{"name":"Frontiers in Microbiology","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11465241/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142399926","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-25eCollection Date: 2024-01-01DOI: 10.3389/fmicb.2024.1446506
Taranjot Kaur, Amanda M V Brown
Bioinformatics sequence data mining can reveal hidden microbial symbionts that might normally be filtered and removed as contaminants. Data mining can be helpful to detect Wolbachia, a widespread bacterial endosymbiont in insects and filarial nematodes whose distribution in plant-parasitic nematodes (PPNs) remains underexplored. To date, Wolbachia has only been reported a few PPNs, yet nematode-infecting Wolbachia may have been widespread in the evolutionary history of the phylum based on evidence of horizontal gene transfers, suggesting there may be undiscovered Wolbachia infections in PPNs. The goal of this study was to more broadly sample PPN Wolbachia strains in tylenchid nematodes to enable further comparative genomic analyses that may reveal Wolbachia's role and identify targets for biocontrol. Published whole-genome shotgun assemblies and their raw sequence data from 33 Meloidogyne spp. assemblies, seven Globodera spp. assemblies, and seven Heterodera spp. assemblies were analyzed to look for Wolbachia. No Wolbachia was found in Meloidogyne spp. and Globodera spp., but among seven genome assemblies for Heterodera spp., an H. schachtii assembly from the Netherlands was found to have a large Wolbachia-like sequence that, when re-assembled from reads, formed a complete, circular genome. Detailed analyses comparing read coverage, GC content, pseudogenes, and phylogenomic patterns clearly demonstrated that the H. schachtii Wolbachia represented a novel strain (hereafter, denoted wHet). Phylogenomic tree construction with PhyloBayes showed wHet was most closely related to another PPN Wolbachia, wTex, while 16S rRNA gene analysis showed it clustered with other Heterodera Wolbachia assembled from sequence databases. Pseudogenes in wHet suggested relatedness to the PPN clade, as did the lack of significantly enriched GO terms compared to PPN Wolbachia strains. It remains unclear whether the lack of Wolbachia in other published H. schachtii isolates represents the true absence of the endosymbiont from some hosts.
{"title":"Discovery of a novel <i>Wolbachia</i> in <i>Heterodera</i> expands nematode host distribution.","authors":"Taranjot Kaur, Amanda M V Brown","doi":"10.3389/fmicb.2024.1446506","DOIUrl":"10.3389/fmicb.2024.1446506","url":null,"abstract":"<p><p>Bioinformatics sequence data mining can reveal hidden microbial symbionts that might normally be filtered and removed as contaminants. Data mining can be helpful to detect <i>Wolbachia</i>, a widespread bacterial endosymbiont in insects and filarial nematodes whose distribution in plant-parasitic nematodes (PPNs) remains underexplored. To date, <i>Wolbachia</i> has only been reported a few PPNs, yet nematode-infecting <i>Wolbachia</i> may have been widespread in the evolutionary history of the phylum based on evidence of horizontal gene transfers, suggesting there may be undiscovered <i>Wolbachia</i> infections in PPNs. The goal of this study was to more broadly sample PPN <i>Wolbachia</i> strains in tylenchid nematodes to enable further comparative genomic analyses that may reveal <i>Wolbachia's</i> role and identify targets for biocontrol. Published whole-genome shotgun assemblies and their raw sequence data from 33 <i>Meloidogyne</i> spp. assemblies, seven <i>Globodera</i> spp. assemblies, and seven <i>Heterodera</i> spp. assemblies were analyzed to look for <i>Wolbachia</i>. No <i>Wolbachia</i> was found in <i>Meloidogyne</i> spp. and <i>Globodera</i> spp., but among seven genome assemblies for <i>Heterodera</i> spp., an <i>H. schachtii</i> assembly from the Netherlands was found to have a large <i>Wolbachia-</i>like sequence that, when re-assembled from reads, formed a complete, circular genome. Detailed analyses comparing read coverage, GC content, pseudogenes, and phylogenomic patterns clearly demonstrated that the <i>H. schachtii Wolbachia</i> represented a novel strain (hereafter, denoted <i>w</i>Het). Phylogenomic tree construction with PhyloBayes showed <i>w</i>Het was most closely related to another PPN <i>Wolbachia, w</i>Tex, while 16S rRNA gene analysis showed it clustered with other <i>Heterodera Wolbachia</i> assembled from sequence databases. Pseudogenes in <i>w</i>Het suggested relatedness to the PPN clade, as did the lack of significantly enriched GO terms compared to PPN <i>Wolbachia</i> strains. It remains unclear whether the lack of <i>Wolbachia</i> in other published <i>H. schachtii</i> isolates represents the true absence of the endosymbiont from some hosts.</p>","PeriodicalId":12466,"journal":{"name":"Frontiers in Microbiology","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11461310/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142389385","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Introduction: Cortinariaceae, which belongs to the Agaricales order, is a globally recognized family, known for its high species diversity.
Methods: Eight internal transcribed spacer (ITS) and nuclear large ribosomal subunit (LSU) sequences were newly generated, and phylogenetic analyses were performed by combining ITS and LSU datasets. Four species were identified as forming four independent lineages with robust support in phylogenies based on both datasets.
Results: These new species in the taxa, Cortinarius gansuensis, Cortinarius tricholomoidus, Cortinarius vinoso-griseum, and Phlegmacium subcalyptratum from Northwestern China are described and illustrated based on morphological and molecular evidence. Cortinarius gansuensis is characterized by a convex and brownish vinaceous pileus, generative hyphae with clamp connections, and ellipsoid basidiospores (8.5-10.6 μm × 5.4-6.8 μm); Cortinarius tricholomoidus is characterized by a broadly umbonate and snuff brown pileus, generative hyphae with clamp connections, and broadly ellipsoid to subglobose basidiospores (7.4-8.5 μm × 6.2-7.3 μm); Cortinarius vinoso-griseum is characterized by a violaceous gray pileus, generative hyphae with clamp connections, and smaller basidiospores (7.5-9.7 μm × 5.6-7.8 μm); and Phlegmacium subcalyptratum is characterized by a small and apricot-orange pileus, generative hyphae with clamp connections, and fusiform basidiospores (10.0-12.7 μm × 5.6-6.8 μm).
Discussion: Full descriptions, illustrations, and results of phylogenetic analyses of the four species along with discussions on related species are provided.
{"title":"Four new species of Cortinariaceae (Agaricales) from Northwestern China.","authors":"Longfei Fan, Xue Zhong, Tianfu Ma, Hongmin Zhou, Biyue Wang, Xiaohong Ji","doi":"10.3389/fmicb.2024.1454736","DOIUrl":"10.3389/fmicb.2024.1454736","url":null,"abstract":"<p><strong>Introduction: </strong>Cortinariaceae, which belongs to the Agaricales order, is a globally recognized family, known for its high species diversity.</p><p><strong>Methods: </strong>Eight internal transcribed spacer (ITS) and nuclear large ribosomal subunit (LSU) sequences were newly generated, and phylogenetic analyses were performed by combining ITS and LSU datasets. Four species were identified as forming four independent lineages with robust support in phylogenies based on both datasets.</p><p><strong>Results: </strong>These new species in the taxa, <i>Cortinarius gansuensis</i>, <i>Cortinarius tricholomoidus</i>, <i>Cortinarius vinoso-griseum</i>, and <i>Phlegmacium subcalyptratum</i> from Northwestern China are described and illustrated based on morphological and molecular evidence. <i>Cortinarius gansuensis</i> is characterized by a convex and brownish vinaceous pileus, generative hyphae with clamp connections, and ellipsoid basidiospores (8.5-10.6 μm × 5.4-6.8 μm); <i>Cortinarius tricholomoidus</i> is characterized by a broadly umbonate and snuff brown pileus, generative hyphae with clamp connections, and broadly ellipsoid to subglobose basidiospores (7.4-8.5 μm × 6.2-7.3 μm); <i>Cortinarius vinoso-griseum</i> is characterized by a violaceous gray pileus, generative hyphae with clamp connections, and smaller basidiospores (7.5-9.7 μm × 5.6-7.8 μm); and <i>Phlegmacium subcalyptratum</i> is characterized by a small and apricot-orange pileus, generative hyphae with clamp connections, and fusiform basidiospores (10.0-12.7 μm × 5.6-6.8 μm).</p><p><strong>Discussion: </strong>Full descriptions, illustrations, and results of phylogenetic analyses of the four species along with discussions on related species are provided.</p>","PeriodicalId":12466,"journal":{"name":"Frontiers in Microbiology","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11461355/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142389398","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Introduction: Fusarium wilt of banana, also recognized as Panama disease, is caused by the soil-borne fungus Fusarium oxysporum f. sp. cubense tropical race 4 (FOC TR4). In recent years, strategies utilizing biocontrol agents, comprising antifungal microorganisms and their associated bioactive compounds from various environments, have been implemented to control this destructive disease. Our previous study showed that Pseudomonas aeruginosa Gxun-2 had significant antifungal effects against FOC TR4. However, there has been little scientific investigation of the antibacterial or antifungal activity. The aim of this study was to isolate, identify and evaluate the inhibition strength of active compounds in P. aeruginosa Gxun-2, so as to explain the mechanism of the strain inhibition on FOC TR4 from the perspective of compounds.
Methods: The main antibacterial compounds of strain Gxun-2 were isolated, purified and identified using by fermentation extraction, silica gel column chromatography, thin-layer chromatography (TLC), high-performance liquid chromatography (HPLC), and nuclear magnetic resonance (NMR) techniques. The effect of the compounds on the mycelial growth, morphology and spore germination of strain FOC TR4 was observed by 96-well plate method and AGAR diffusion method.
Results: Among the metabolites produced by the strain, four antifungal compounds which were identified phenazine (C12H8N2), phenazine-1-carboxylic acid (PCA) (C13H8N2O2), 2-acetamidophenol (C8H9NO2) and aeruginaldehyde (C10H7NO2S) were identified through HPLC and NMR. Of these compounds, phenazine and PCA exhibited the most pronounced inhibitory effects on the spore germination and mycelial growth of FOC TR4. Phenazine demonstrated potent antifungal activity against FOC TR4 with a minimum inhibitory concentration (MIC) of 6.25 mg/L. The half-maximal effective concentration (EC50) was calculated to be 26.24 mg/L using the toxicity regression equation. PCA exhibited antifungal activity against FOC TR4 with an MIC of 25 mg/L and an EC50 of 89.63 mg/L. Furthermore, phenazine and PCA triggered substantial morphological transformations in the mycelia of FOC TR4, encompassing folding, bending, fracturing, and diminished spore formation.
Discussion: These findings indicate that strain Gxun-2 plays a crucial role in controlling FOC TR4 pathogenesis, predominantly through producing the antifungal compounds phenazine and PCA, and possesses potential as a cost-efficient and sustainable biocontrol agent against Fusarium wilt of banana in forthcoming times.
{"title":"Antimicrobial mechanisms and antifungal activity of compounds generated by banana rhizosphere <i>Pseudomonas aeruginosa</i> Gxun-2 against <i>fusarium oxysporum</i> f. sp. <i>cubense</i>.","authors":"Junming Lu, Yanbing Huang, Rui Liu, Ying Liang, Hongyan Zhang, Naikun Shen, Dengfeng Yang, Mingguo Jiang","doi":"10.3389/fmicb.2024.1456847","DOIUrl":"10.3389/fmicb.2024.1456847","url":null,"abstract":"<p><strong>Introduction: </strong><i>Fusarium</i> wilt of banana, also recognized as Panama disease, is caused by the soil-borne fungus <i>Fusarium oxysporum</i> f. sp. <i>cubense</i> tropical race 4 (FOC TR4). In recent years, strategies utilizing biocontrol agents, comprising antifungal microorganisms and their associated bioactive compounds from various environments, have been implemented to control this destructive disease. Our previous study showed that <i>Pseudomonas aeruginosa</i> Gxun-2 had significant antifungal effects against FOC TR4. However, there has been little scientific investigation of the antibacterial or antifungal activity. The aim of this study was to isolate, identify and evaluate the inhibition strength of active compounds in <i>P. aeruginosa</i> Gxun-2, so as to explain the mechanism of the strain inhibition on FOC TR4 from the perspective of compounds.</p><p><strong>Methods: </strong>The main antibacterial compounds of strain Gxun-2 were isolated, purified and identified using by fermentation extraction, silica gel column chromatography, thin-layer chromatography (TLC), high-performance liquid chromatography (HPLC), and nuclear magnetic resonance (NMR) techniques. The effect of the compounds on the mycelial growth, morphology and spore germination of strain FOC TR4 was observed by 96-well plate method and AGAR diffusion method.</p><p><strong>Results: </strong>Among the metabolites produced by the strain, four antifungal compounds which were identified phenazine (C<sub>12</sub>H<sub>8</sub>N<sub>2</sub>), phenazine-1-carboxylic acid (PCA) (C<sub>13</sub>H<sub>8</sub>N<sub>2</sub>O<sub>2</sub>), 2-acetamidophenol (C<sub>8</sub>H<sub>9</sub>NO<sub>2</sub>) and aeruginaldehyde (C<sub>10</sub>H<sub>7</sub>NO<sub>2</sub>S) were identified through HPLC and NMR. Of these compounds, phenazine and PCA exhibited the most pronounced inhibitory effects on the spore germination and mycelial growth of FOC TR4. Phenazine demonstrated potent antifungal activity against FOC TR4 with a minimum inhibitory concentration (MIC) of 6.25 mg/L. The half-maximal effective concentration (EC<sub>50</sub>) was calculated to be 26.24 mg/L using the toxicity regression equation. PCA exhibited antifungal activity against FOC TR4 with an MIC of 25 mg/L and an EC<sub>50</sub> of 89.63 mg/L. Furthermore, phenazine and PCA triggered substantial morphological transformations in the mycelia of FOC TR4, encompassing folding, bending, fracturing, and diminished spore formation.</p><p><strong>Discussion: </strong>These findings indicate that strain Gxun-2 plays a crucial role in controlling FOC TR4 pathogenesis, predominantly through producing the antifungal compounds phenazine and PCA, and possesses potential as a cost-efficient and sustainable biocontrol agent against <i>Fusarium</i> wilt of banana in forthcoming times.</p>","PeriodicalId":12466,"journal":{"name":"Frontiers in Microbiology","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11461210/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142389367","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-09-25eCollection Date: 2024-01-01DOI: 10.3389/fmicb.2024.1399996
Maria Salazar, Siavash Shahbazi Nia, Nadezhda A German, Babafela Awosile, Saheed Sabiu, Alexandra Calle
Staphylococcus aureus is a bacterial pathogen of considerable significance in public health, capable of inducing a diverse range of infectious diseases. One of the most notorious mechanisms used by S. aureus to survive and colonize the site of infection is its ability to form biofilms. Diflunisal, a non-steroidal anti-inflammatory drug (NSAID), is a known inhibitor of the Agr system in S. aureus, which is key in regulating biofilm formation. This study evaluated the effect of broad-spectrum antibiotics in combination with diflunisal on S. aureus biofilm density. Eight antibiotics were tested independently at different concentrations and in combination with diflunisal to assess their effect on S. aureus biofilm formation. When using the antibiotics alone and with diflunisal, a significant control effect on biofilm formation was observed (p < 0.05), irrespective of diflunisal presence, but did not achieve a complete biofilm growth inhibition. Over time, diflunisal influenced biofilm formation; however, such an effect was correlated with antibiotic concentration and exposure time. With amikacin treatments, biofilm density increased with extended exposure time. In the case of imipenem, doripenem, levofloxacin, and ciprofloxacin, lower doses and absence of diflunisal showed higher control over biofilm growth with longer exposure. However, in all cases, diflunisal did not significantly affect the treatment effect on biofilm formation. In the absence of antibiotics, diflunisal significantly reduced biofilm formation by 53.12% (p < 0.05). This study suggests that diflunisal could be a potential treatment to control S. aureus biofilms, but it does not enhance biofilm inhibition when combined with antibiotics.
金黄色葡萄球菌是一种对公共卫生具有重要意义的细菌病原体,能够诱发多种传染性疾病。金黄色葡萄球菌赖以生存并在感染部位定植的最臭名昭著的机制之一就是其形成生物膜的能力。非甾体抗炎药(NSAID)双氟尼沙是一种已知的金黄色葡萄球菌 Agr 系统抑制剂,而 Agr 系统是调节生物膜形成的关键。本研究评估了广谱抗生素与双氟尼沙联合使用对金黄色葡萄球菌生物膜密度的影响。八种抗生素分别以不同浓度与地氟尼沙联合使用进行了测试,以评估其对金黄色葡萄球菌生物膜形成的影响。在单独使用抗生素和与二氟尼柳联合使用时,观察到了对生物膜形成的显著控制效果(p p 金黄色葡萄球菌生物膜),但与抗生素联合使用时,二氟尼柳不会增强对生物膜的抑制作用。
{"title":"Exploring diflunisal as a synergistic agent against <i>Staphylococcus aureus</i> biofilm formation.","authors":"Maria Salazar, Siavash Shahbazi Nia, Nadezhda A German, Babafela Awosile, Saheed Sabiu, Alexandra Calle","doi":"10.3389/fmicb.2024.1399996","DOIUrl":"10.3389/fmicb.2024.1399996","url":null,"abstract":"<p><p><i>Staphylococcus aureus</i> is a bacterial pathogen of considerable significance in public health, capable of inducing a diverse range of infectious diseases. One of the most notorious mechanisms used by <i>S. aureus</i> to survive and colonize the site of infection is its ability to form biofilms. Diflunisal, a non-steroidal anti-inflammatory drug (NSAID), is a known inhibitor of the Agr system in <i>S. aureus</i>, which is key in regulating biofilm formation. This study evaluated the effect of broad-spectrum antibiotics in combination with diflunisal on <i>S. aureus</i> biofilm density. Eight antibiotics were tested independently at different concentrations and in combination with diflunisal to assess their effect on <i>S. aureus</i> biofilm formation. When using the antibiotics alone and with diflunisal, a significant control effect on biofilm formation was observed (<i>p</i> < 0.05), irrespective of diflunisal presence, but did not achieve a complete biofilm growth inhibition. Over time, diflunisal influenced biofilm formation; however, such an effect was correlated with antibiotic concentration and exposure time. With amikacin treatments, biofilm density increased with extended exposure time. In the case of imipenem, doripenem, levofloxacin, and ciprofloxacin, lower doses and absence of diflunisal showed higher control over biofilm growth with longer exposure. However, in all cases, diflunisal did not significantly affect the treatment effect on biofilm formation. In the absence of antibiotics, diflunisal significantly reduced biofilm formation by 53.12% (<i>p</i> < 0.05). This study suggests that diflunisal could be a potential treatment to control <i>S. aureus</i> biofilms, but it does not enhance biofilm inhibition when combined with antibiotics.</p>","PeriodicalId":12466,"journal":{"name":"Frontiers in Microbiology","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11461217/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142389397","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}