Flore Oudouhou, Claire Morin, Mickael Bouin, Christiane Gaudreau, Christian Baron
{"title":"Inhibition of the type IV secretion system from antibiotic-resistant <i>Helicobacter pylori</i> clinical isolates supports the potential of Cagα as an anti-virulence target.","authors":"Flore Oudouhou, Claire Morin, Mickael Bouin, Christiane Gaudreau, Christian Baron","doi":"10.1139/cjm-2023-0168","DOIUrl":"10.1139/cjm-2023-0168","url":null,"abstract":"<p><p><i>Helicobacter pylori</i> resistance to antibiotics is a growing problem and it increasingly leads to treatment failure. While the bacterium is present worldwide, the severity of clinical outcomes is highly dependent on the geographical origin and genetic characteristics of the strains. One of the major virulence factors identified in <i>H. pylori</i> is the <i>cag</i> pathogenicity island (<i>cag</i>PAI), which encodes a type IV secretion system (T4SS) used to translocate effectors into human cells. Here, we investigated the genetic variability of the <i>cag</i>PAI among 13 antibiotic-resistant <i>H. pylori</i> strains that were isolated from patient biopsies in Québec. Seven of the clinical strains carried the <i>cag</i>PAI, but only four could be readily cultivated under laboratory conditions. We observed variability of the sequences of CagA and CagL proteins that are encoded by the <i>cag</i>PAI. All clinical isolates induce interleukin-8 secretion and morphological changes upon co-incubation with gastric cancer cells and two of them produce extracellular T4SS pili. Finally, we demonstrate that molecule 1G2, a small molecule inhibitor of the Cagα protein from the model strain <i>H. pylori</i> 26695, reduces interleukin-8 secretion in one of the clinical isolates. Co-incubation with 1G2 also inhibits the assembly of T4SS pili, suggesting a mechanism for its action on T4SS function.</p>","PeriodicalId":9381,"journal":{"name":"Canadian journal of microbiology","volume":" ","pages":"119-127"},"PeriodicalIF":2.8,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139097367","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}
Luis Enrique Chaves-González, Daniela Jaikel-Víquez, Stefany Lozada-Alvarado, Fabio Granados-Chinchilla
{"title":"Unveiling the fungal color palette: pigment analysis of <i>Fusarium solani</i> species complex and <i>Curvularia verruculosa</i> clinical isolates.","authors":"Luis Enrique Chaves-González, Daniela Jaikel-Víquez, Stefany Lozada-Alvarado, Fabio Granados-Chinchilla","doi":"10.1139/cjm-2023-0181","DOIUrl":"10.1139/cjm-2023-0181","url":null,"abstract":"<p><p>Fungal species in the <i>Nectriaceae</i>, such as <i>Fusarium</i> spp. (<i>Hypocreales: Nectriaceae</i>), are etiologic agents of hyalohyphomycosis capable of producing violaceous or yellowish pigments under certain conditions, while <i>Curvularia</i> spp. (<i>Pleosporales: Pleosporaceae</i>) are agents of phaeohyphomycosis and typically produce melanin in their cell walls. In nectriaceous and pleosporaceous fungi, these pigments are mainly constituted by polyketides (e.g., azaphilones, naphthoquinones, and hydroxyanthraquinones). Considering the importance of pigments synthesized by these genera, this work focused on the selective extraction of pigments produced by eight <i>Fusarium solani</i> species complex and one <i>Curvularia verruculosa</i> isolate recovered from dermatomycosis specimens, their separation, purification, and posterior chemical analysis. The pigments were characterized through spectral and acid-base analysis, and their maximum production time was determined. Moreover, spectral identification of isolates was carried out to approach the taxonomic specificity of pigment production. Herein we describe the isolation and characterization of three acidic pigments, yellowish and pinkish azaphilones (i.e., coaherin A and sclerotiorin), and a purplish xanthone, reported for the first time in the <i>Nectriaceae</i> and <i>Pleosporaceae</i>, which appear to be synthesized in a species-independent manner, in the case of fusaria.</p>","PeriodicalId":9381,"journal":{"name":"Canadian journal of microbiology","volume":" ","pages":"135-149"},"PeriodicalIF":2.8,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139485250","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":"<i>Enterococcus faecium</i> inhibits NF-κB/NLRP3/Caspase-1 signaling pathway to antagonize enterotoxigenic <i>Escherichia coli</i>-mediated inflammatory response.","authors":"Huibin Zheng, Sicheng Pu, Jiahao Liu, Falong Yang, Dechun Chen","doi":"10.1139/cjm-2023-0038","DOIUrl":"10.1139/cjm-2023-0038","url":null,"abstract":"<p><p>Enterotoxigenic <i>Escherichia coli</i> (ETEC) can cause intestinal inflammation and diarrhea in yaks, which has a negative impact on their economic value. In recent years, probiotics have gained increasing attention as a pure, natural, nontoxic, harmless, and residue-free additive. However, the underlying mechanisms by which probiotics safeguard against ETEC are not completely elucidated. This study aimed to investigate the protective effect of <i>Enterococcus faecium</i> (<i>E. faecium</i>) against ETEC infection in mice through oral gavage. Morphological changes were examined through light microscopy. The expressions of inflammatory cytokines (IL-1β, IL-6, TNF-α, IL-10, NF-κB, and NLRP3), tight junction protein (ZO-1, Claudin-1), and pyroptosis (Caspase-1, Caspase-4, and gasdermin D (GSDMD)) were detected using immunohistochemistry and quantitative real-time PCR. The results indicate that ETEC infection triggers the activation of inflammation-related pathways (NF-κB) and NLRP3 inflammasome, leading to the expression of a large number of inflammatory cytokines. Additionally, the activation of NLRP3 leads to the release of GSDMD activation through Caspase-1, ultimately resulting in inflammatory injury and pyroptosis. Feeding mice <i>E. faecium</i> early resulted in an increase in the expression of tight junction protein, a reduction in inflammatory cytokines, and alleviation of inflammatory injury and pyroptosis in intestinal tissues. Our research indicates that <i>E. faecium</i> has the ability to antagonize ETEC and provide protection to the gastrointestinal mucosa in mice.</p>","PeriodicalId":9381,"journal":{"name":"Canadian journal of microbiology","volume":" ","pages":"109-118"},"PeriodicalIF":2.8,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138884485","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}
Xue Li, Wei Lian, Miaomiao Zhang, Xi Luo, Yiquan Zhang, Renfei Lu
{"title":"QsvR and OpaR coordinately regulate the transcription of <i>cpsS</i> and <i>cpsR</i> in <i>Vibrio parahaemolyticus</i>.","authors":"Xue Li, Wei Lian, Miaomiao Zhang, Xi Luo, Yiquan Zhang, Renfei Lu","doi":"10.1139/cjm-2023-0196","DOIUrl":"10.1139/cjm-2023-0196","url":null,"abstract":"<p><p><i>Vibrio parahaemolyticus</i>, the leading cause of seafood-associated gastroenteritis, has a strong capacity to form biofilms on surfaces, which is strictly regulated by the CpsS-CpsR-CpsQ regulatory cascade. OpaR, a master regulator of quorum sensing, is a global regulator that controls multiple cellular pathways including biofilm formation and virulence. QsvR is an AraC-type regulator that works coordinately with OpaR to control biofilm formation and virulence gene expression of <i>V. parahaemolyticus</i>. QsvR and OpaR activate <i>cpsQ</i> transcription. OpaR also activates <i>cpsR</i> transcription, but lacks the detailed regulatory mechanisms. Furthermore, it is still unknown whether QsvR regulates <i>cpsR</i> transcription, as well as whether QsvR and OpaR regulate <i>cpsS</i> transcription. In this study, the results of quantitative real-time PCR and LacZ fusion assays demonstrated that deletion of <i>qsvR</i> and/or <i>opaR</i> significantly decreased the expression levels of <i>cpsS</i> and <i>cpsR</i> compared to the wild-type strain. However, the results of two-plasmid <i>lacZ</i> reporter and electrophoretic mobility-shift assays showed that both QsvR and OpaR were unable to bind the regulatory DNA regions of <i>cpsS</i> and <i>cpsR</i>. Therefore, transcription of <i>cpsS</i> and <i>cpsR</i> was coordinately and indirectly activated by QsvR and OpaR. This work enriched our knowledge on the regulatory network of biofilm formation in <i>V. parahaemolyticus</i>.</p>","PeriodicalId":9381,"journal":{"name":"Canadian journal of microbiology","volume":" ","pages":"128-134"},"PeriodicalIF":2.8,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139982431","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":"Hydrogen sulfide regulates arsenic-induced cell death in yeast cells by modulating the antioxidative system.","authors":"Lihua Wu, Xia Yao, Haiyan Li, Yanfei Chen","doi":"10.1139/cjm-2023-0068","DOIUrl":"10.1139/cjm-2023-0068","url":null,"abstract":"<p><p>Arsenic (As) is a metal with potentially toxic effects on different organisms. Hydrogen sulfide (H<sub>2</sub>S) plays a vital role in mitigating heavy metal toxicity by reducing oxidative stress in plants and animals. However, the role of H<sub>2</sub>S in alleviating arsenic toxicity in yeast cells remains unclear. In this study, the role of NaHS (exogenous physiological H<sub>2</sub>S) in alleviating As-induced yeast cell death was investigated. Yeast cells in the logarithmic phase were pretreated with 0.05 mmol/L NaHS for 6 h, and then incubated in the YPD medium with or without 1 mmol/L As. After 12 h of treatment, relative survival rate, H<sub>2</sub>S content, oxidative stress biomarkers, and antioxidant machinery were measured. Our results showed that sodium arsenite-induced yeast cell death and pretreatment with 0.05 mmol/L NaHS significantly alleviated sodium arsenite-induced cell death. Under sodium arsenite conditions, the levels of intracellular reactive oxygen species (ROS) and malondialdehyde (MDA) increased, accompanied by the inhibition of the catalase (CAT) activity and the downregulation of <i>CTT1</i> expression. However, the activities of the superoxide dismutase (SOD) and glutathion peroxidase (GPX) increased, and the expression of <i>SOD1</i> and <i>GPX2</i> was markedly upregulated in the group treated with sodium arsenite. When yeast cells were pretreated with NaHS, the intracellular ROS and MDA levels decreased significantly, and the activities of SOD, CAT, and GPX increased significantly. This was associated with a significant increase in relative survival rate and H<sub>2</sub>S content compared to the arsenic treatment alone. Our findings indicate that NaHS alleviates sodium arsenite-induced yeast cell death, mainly by enhancing the antioxidant defense system.</p>","PeriodicalId":9381,"journal":{"name":"Canadian journal of microbiology","volume":" ","pages":"102-108"},"PeriodicalIF":2.8,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138797146","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":"Changes in the soil fungal communities of steppe grasslands at varying degradation levels in North China.","authors":"Qiqi Han, Yuhang Chen, Zichao Li, Zhuo Zhang, Yuao Qin, Zhongkuan Liu, Guixia Liu","doi":"10.1139/cjm-2023-0105","DOIUrl":"10.1139/cjm-2023-0105","url":null,"abstract":"<p><p>The grasslands in North China are rich in fungal resources. However, the knowledge of the structure and function of fungal communities and the role of microbial communities in vegetation restoration and succession are limited. Thus, we used an Illumina HiSeq PE250 high-throughput sequencing platform to study the changing characteristics of soil fungal communities in degraded grasslands, which were categorized as non-degraded (ND), lightly degraded, moderately degraded, and severely degraded (SD). Moreover, a correlation analysis between soil physical and chemical properties and fungal communities was completed. The results showed that the number of plant species, vegetation coverage, aboveground biomass, and diversity index decreased significantly with increasing degradation, and there were significant differences in the physical and chemical properties of the soil among the different degraded grasslands. The dominant fungal phyla in the degraded grassland were as follows: Ascomycota, 44.88%-65.03%; Basidiomycota, 12.68%-29.91%; and unclassified, 5.51%-16.91%. The dominant fungi were as follows: Mortierella, 6.50%-11.41%; <i>Chaetomium</i>, 6.71%-11.58%; others, 25.95%-36.14%; and unclassified, 25.56%-53.0%. There were significant differences in the microbial Shannon-Wiener and Chao1 indices between the ND and degraded meadows, and the composition and diversity of the soil fungal community differed significantly as the meadows continued to deteriorate. The results showed that pH was the most critical factor affecting soil microbial and fungal communities in SD grasslands, whereas soil microbial and fungal communities in ND grasslands were mainly affected by water content and other environmental factors.</p>","PeriodicalId":9381,"journal":{"name":"Canadian journal of microbiology","volume":" ","pages":"70-85"},"PeriodicalIF":2.8,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138797099","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":"Genome and transcriptome sequencing of <i>Trichoderma harzianum</i> T4, an important biocontrol fungus of <i>Rhizoctonia solani</i>, reveals genes related to mycoparasitism.","authors":"Yaping Wang, Jian Wang, Xiaochong Zhu, Wei Wang","doi":"10.1139/cjm-2023-0148","DOIUrl":"10.1139/cjm-2023-0148","url":null,"abstract":"<p><p><i>Trichoderma harzianum</i> is a well-known biological control strain and a mycoparasite of <i>Rhizoctonia solani</i>. To explore the mechanisms of mycoparasitism, the genome and transcriptome of <i>T. harzianum</i> T4 were both assembled and analyzed in this study. The genome of <i>T. harzianum</i> T4 was assembled into 106 scaffolds, sized 41.25 Mb, and annotated with a total of 8118 predicted genes. We analyzed the transcriptome of <i>T. harzianum</i> T4 against <i>R. solani</i> in a dual culture in three culture periods: before contact (BC), during contact (C), and after contact (AC). Transcriptome sequencing identified 1092, 1222, and 2046 differentially expressed genes (DEGs), respectively. These DEGs, which are involved in pathogen recognition and signal transduction, hydrolase, transporters, antibiosis, and defense-related functional genes, are significantly upregulated in the mycoparasitism process. The results of genome and transcriptome analysis indicated that the mycoparasitism process of <i>T. harzianum</i> T4 was very complex. <i>T. harzianum</i> successfully recognizes and invades host cells and kills plant pathogens by regulating various DEGs at different culture periods. The relative expression levels of the 26 upregulated DEGs were confirmed by RT-qPCR to validate the reliability of the transcriptome data. The results provide insight into the molecular mechanisms underlying <i>T. harzianum</i> T4's mycoparasitic processes, and they provide a potential molecular target for the biological control mechanism of <i>T. harzianum</i> T4.</p>","PeriodicalId":9381,"journal":{"name":"Canadian journal of microbiology","volume":" ","pages":"86-101"},"PeriodicalIF":2.8,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139691217","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":"Note of appreciation.","authors":"","doi":"10.1139/cjm-2023-0152","DOIUrl":"10.1139/cjm-2023-0152","url":null,"abstract":"","PeriodicalId":9381,"journal":{"name":"Canadian journal of microbiology","volume":"70 1","pages":"i"},"PeriodicalIF":2.8,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139073367","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}
Scott Roscoe, Yue Guo, Panayiotis O Vacratsis, Sirinart Ananvoranich
{"title":"Proteomic profile of <i>Toxoplasma</i> <i>gondii</i> stress granules by high-resolution mass spectrometry.","authors":"Scott Roscoe, Yue Guo, Panayiotis O Vacratsis, Sirinart Ananvoranich","doi":"10.1139/cjm-2023-0091","DOIUrl":"10.1139/cjm-2023-0091","url":null,"abstract":"<p><p>Ribonucleoprotein granules are bio-condensates that form a diverse group of dynamic membrane-less organelles implicated in several cellular functions, including stress response and cellular survival. In <i>Toxoplasma gondii</i>, a type of bio-condensates referred to as stress granules (SGs) are formed prior to the parasites' egress from the host cell and are implicated in the survival and invasion competency of extracellular tachyzoites. We used paraformaldehyde to fix and cross-link SG proteins to allow purification by centrifugation and analysis by mass spectrometry. We profiled protein components of SGs at 10 and 30 min post-egress when parasite's invasion ability is significantly diminished. Thirty-three proteins were identified from 10 min SGs, and additional 43 proteins were identified from 30 min SGs. Notably, common SG components such as proteins with intrinsically disordered domains were not identified. Gene ontology analysis of both 10 and 30 min SGs shows that overall molecular functions of SGs' proteins are ATP-binding, GTP-binding, and GTPase activity. Discernable differences between 10 and 30 min SGs are in the proportions of translation and microtubule-related proteins. Ten-minute SGs have a higher proportion of microtubule-related proteins and a lower proportion of ribosome-related proteins, while a reverse correlation was identified for those of 30 min. It remains to be investigated whether this reverse correlation contributes to the ability of extracellular tachyzoites to reinvade host cells.</p>","PeriodicalId":9381,"journal":{"name":"Canadian journal of microbiology","volume":" ","pages":"32-39"},"PeriodicalIF":2.8,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41192008","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}
Nasim Maghboli Balasjin, James S Maki, Michael R Schläppi
{"title":"<i>Pseudomonas mosselii</i> improves cold tolerance of Asian rice (<i>Oryza sativa</i> L.) in a genotype-dependent manner by increasing proline in <i>japonica</i> and reduced glutathione in <i>indica</i> varieties.","authors":"Nasim Maghboli Balasjin, James S Maki, Michael R Schläppi","doi":"10.1139/cjm-2023-0030","DOIUrl":"10.1139/cjm-2023-0030","url":null,"abstract":"<p><p>Cold stress is an important factor limiting rice production and distribution. Identifying factors that contribute to cold tolerance in rice is of primary importance. While some plant specific genetic factors involved in cold tolerance have been identified, the role of the rice microbiome remains unexplored. In this study, we evaluated the influence of plant growth promoting bacteria (PGPB) with the ability of phosphate solubilization on rice cold tolerance and survival. To reach this goal, inoculated and uninoculated 2-week-old seedlings were cold stressed and evaluated for survival and other phenotypes such as electrolyte leakage (EL) and necessary elements for cold tolerance. The results of this study showed that of the five bacteria, <i>Pseudomonas mosselii</i>, improved both <i>indica</i> and <i>japonica</i> varietal plants' survival and decreased EL, indicating increased membrane integrity. We observed different possible cold tolerance mechanisms in <i>japonica</i> and <i>indica</i> plants such as increases in proline and reduced glutathione levels, respectively. This bacterium also improved the shoot growth of cold exposed <i>indica</i> plants during the recovery period. This study confirmed the host genotype dependent activity of <i>P. mosselii</i> and indicated that there is an interaction between specific plant genes and bacterial genes that causes different plant responses to cold stress.</p>","PeriodicalId":9381,"journal":{"name":"Canadian journal of microbiology","volume":" ","pages":"15-31"},"PeriodicalIF":2.8,"publicationDate":"2024-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10277621","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}