mSphere最新文献

{"title":"<i>Toxoplasma gondii</i> PROP1 is critical for autophagy and parasite viability during chronic infection.","authors":"Pariyamon Thaprawat, Fengrong Wang, Shreya Chalasani, Tracey L Schultz, Manlio Di Cristina, Vern B Carruthers","doi":"10.1128/msphere.00829-24","DOIUrl":"https://doi.org/10.1128/msphere.00829-24","url":null,"abstract":"<p><p>Macroautophagy is an important cellular process involving lysosomal degradation of cytoplasmic components, facilitated by autophagy-related proteins. In the protozoan parasite <i>Toxoplasma gondii</i>, autophagy has been demonstrated to play a key role in adapting to stress and the persistence of chronic infection. Despite limited knowledge about the core autophagy machinery in <i>T. gondii</i>, two PROPPIN family proteins (TgPROP1 and TgPROP2) have been identified with homology to Atg18/WIPI. Prior research in acute-stage tachyzoites suggests that TgPROP2 is predominantly involved in a non-autophagic function, specifically apicoplast biogenesis, while TgPROP1 may be involved in canonical autophagy. Here, we investigated the distinct roles of TgPROP1 and TgPROP2 in chronic stage <i>T. gondii</i> bradyzoites, revealing a critical role for TgPROP1, but not TgPROP2, in bradyzoite autophagy. Conditional knockdown of TgPROP2 did not impair bradyzoite autophagy. In contrast, TgPROP1 KO parasites had impaired autolysosome formation, reduced cyst burdens in chronically infected mice, and decreased viability. Together, our findings clarify the indispensable role of TgPROP1 to <i>T. gondii</i> autophagy and chronic infection.</p><p><strong>Importance: </strong>It is estimated that up to a third of the human population is chronically infected with <i>Toxoplasma gondii</i>; however, little is known about how this parasite persists long term within its hosts. Autophagy is a self-eating pathway that has recently been shown to play a key role in parasite persistence, yet few proteins that carry out this process during <i>T. gondii</i> chronic infection are known. Here, we provide evidence for a non-redundant role of TgPROP1, a protein important in the early steps of the autophagy pathway. Genetic disruption of TgPROP1 resulted in impaired autophagy and chronic infection of mice. Our results reveal a critical role for TgPROP1 in autophagy and underscore the importance of this pathway in parasite persistence.</p>","PeriodicalId":19052,"journal":{"name":"mSphere","volume":" ","pages":"e0082924"},"PeriodicalIF":3.7,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143468574","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"<i>Bifidobacterium longum</i> increases serum vitamin D metabolite levels and modulates intestinal flora to alleviate osteoporosis in mice.","authors":"Hongchao Wang, Gao Tian, Zhangming Pei, Xihua Yu, Yi Wang, Fuchun Xu, Jianxin Zhao, Shourong Lu, Wenwei Lu","doi":"10.1128/msphere.01039-24","DOIUrl":"https://doi.org/10.1128/msphere.01039-24","url":null,"abstract":"<p><p>The elderly population is prone to osteoporosis, owing to the deterioration of the skin, liver, and kidney functions. Vitamin D (VD) supplementation has a limited effect, and VD deficiency is mostly treated with medication. Several studies have shown that the gut microbiota alters intestinal VD metabolism and that probiotic supplements can influence circulating VD levels. Therefore, in the present study, we screened a strain of <i>Bifidobacterium longum</i> FSHHK13M1 that can increase the level of VD metabolites in the fermented supernatant species <i>in vitro</i> by modeling fecal bacterial fermentation. The results showed that FSHHK13M1 intervention significantly increased the serum levels of 1,25-dihydroxy VD and osteocalcin. It activated the expression of the VDR, OPG, Wnt10b/β-catenin, and Runx2/Osterix pathways and inhibited the expression of RANKL/RANK pathway. Furthermore, there was an enhancement in the quantity of bone trabeculae and the proportion of bone volume. Concurrently, the gut microbiota in mice with osteoporosis exhibited signs of imbalance. FSHHK13M1 intervention increased the relative abundance of specific bacteria, such as <i>Faecalibaculum rodentium</i>, <i>Limosilactobacillus fermentum</i>, <i>Bifidobacterium pseudolongum</i>, and <i>Akkermansia muciniphila</i>. These results suggest that <i>B. longum</i> FSHHK13M1 alleviates retinoic acid-induced osteoporosis symptoms by modulating related genes, regulating the intestinal flora and increasing the level of active VD.IMPORTANCEOsteoporosis is a systemic metabolic disease in which the patient's bone mass decreases for a variety of reasons, and the microstructure of the bone tissue is altered, leading to an increase in bone brittleness and susceptibility to fracture. Osteoporosis is almost always present in the elderly population, and fractures from falls are an important predisposing factor for mortality risk in the elderly population. Supplementation is quite limited for them as they are not able to utilize vitamin D well due to declining liver, kidney, and skin functions. In the present study, a strain of <i>Bifidobacterium longum</i> probiotic was found to increase the levels of the active form of vitamin D and ameliorate osteoporosis. This may play an important role in preventing osteoporosis and reducing fracture risk in the elderly.</p>","PeriodicalId":19052,"journal":{"name":"mSphere","volume":" ","pages":"e0103924"},"PeriodicalIF":3.7,"publicationDate":"2025-02-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143468461","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Cross-laboratory replication of pseudomyxoma peritonei tumor microbiome reveals reproducible microbial signatures.","authors":"Victoria F Nieciecki, Faith C Blum, Ryan C Johnson, Traci L Testerman, Tom J McAvoy, Mary Caitlin King, Vadim Gushchin, Jeannette M Whitmire, Kenneth G Frey, Lindsay Glang, Dessiree Peña-Gomez, Kimberly A Bishop-Lilly, Armando Sardi, D Scott Merrell, Jessica L Metcalf","doi":"10.1128/msphere.00652-24","DOIUrl":"https://doi.org/10.1128/msphere.00652-24","url":null,"abstract":"<p><p>Recent work has demonstrated that cancer-specific microbial communities often colonize tumor tissues. However, untangling low-biomass signals from environmental contamination makes this research technically challenging. We utilize pseudomyxoma peritonei (PMP), a cancer characterized by the spread of mucus-secreting cells throughout the peritoneal cavity, to develop a robust workflow for identifying reproducible tumor microbiomes. Typically originating from the rupture of an appendiceal tumor into the peritoneal cavity, metastasized tumors have been previously shown to harbor a core set of microbes. However, that work did not control for the potential contamination of these low microbial biomass samples. We expand upon these prior findings by characterizing the microbiome of 70 additional PMP tumors and six normal peritoneal control tissues along with appropriate laboratory controls. Additionally, DNA from a subset of 25 tissues was extracted and sequenced at an independent laboratory. We found evidence of reproducible microbial signatures between the replicates of six different PMP tumors that include a set of core taxa that may be introduced from surgical contamination, as well as patient-specific taxa that are also commonly implicated in colorectal cancer. In addition, preoperative chemotherapy treatment was found to reduce tumor microbiome diversity. Our findings demonstrate how independent sample replication can be a powerful approach to investigate low-biomass microbial communities associated with tumor tissues that will improve low microbial biomass research.IMPORTANCERecent work has demonstrated that microbial communities colonize over 30 different types of tumor tissues. The origin of these communities and their possible involvement in carcinogenesis or cancer treatment outcomes remains an unclear, yet important area of research. A current major challenge in characterizing low-biomass, tumor-associated microbiomes is the introduction of environmental contamination during collection, handling, DNA extraction, PCR, and sequencing. Here, we provide a framework for replicating low-biomass tumor microbiome samples to help identify tumors with robust microbial signals and low background contamination. Using this replication approach, we show that pseudomyxoma peritonei (PMP) tumors host reproducible microbial communities, including organisms that have previously been associated with colorectal cancer. Incorporating sample replication into future tumor microbiome studies is a promising approach that will help identify robust signals and increase reproducibility in the field.</p>","PeriodicalId":19052,"journal":{"name":"mSphere","volume":" ","pages":"e0065224"},"PeriodicalIF":3.7,"publicationDate":"2025-02-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143458622","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prospective comparison of the digestive tract resistome and microbiota in cattle raised in grass-fed versus grain-fed production systems.","authors":"Jiye Kwon, Windy Tanner, Yong Kong, Martina Wade, Chad Bitler, Marilia B Chiavegato, Melinda M Pettigrew","doi":"10.1128/msphere.00738-24","DOIUrl":"https://doi.org/10.1128/msphere.00738-24","url":null,"abstract":"<p><p>Most antimicrobials sold in the United States are used in food animals. Farm management practices contribute to antibacterial resistance (AR). Controversially, grass-fed diets have been recommended over grain-fed diets to reduce AR in beef cattle. Ionophore feed additives (non-therapeutic antibiotics that enhance feed efficiency) may contribute to AR development. We used shotgun metagenomic sequencing of fecal swabs to prospectively compare the cattle gastrointestinal resistome and microbiota in two different production systems over five periods from pre-weaning to pre-harvest. Cattle were grass-fed and pasture-raised (system A, <i>n</i> = 33) or grain-fed with ionophore additives in feedlots (system B, <i>n</i> = 34). System A cattle averaged 639 lb and 22.8 months of age, and system B cattle averaged 1,173 lb and 12.4 months of age preharvest. In total, 367 antibiotic resistance genes (ARGs) and 329 bacterial species were identified. The resistome of system A cattle had higher alpha diversity than system B cattle over their lifespan (<i>P</i> = 0.008). Beta-diversity estimates indicated overlap in the pre-weaning resistome and microbiota in both systems, which diverged post-weaning, with increases in several medically important ARGs when system B cattle transitioned to a grain diet. Analysis of compositions of microbiomes with bias correction indicated that levels of tetracycline, macrolide, aminoglycoside, beta-lactam, and bacitracin ARGs were significantly higher in system B cattle pre-harvest. Resistome changes were highly correlated with bacterial community changes (Procrustes, <i>M</i>² = 0.958; <i>P</i> = 0.001). Potentially modifiable farm management strategies, including diet and ionophores, may influence abundance and diversity of ARGs in fecal samples from cattle.IMPORTANCEAntibiotic resistance is a One Health threat. More antibiotics are used in agriculture than in human medicine. We compared the relative abundance of antibiotic resistance genes (ARGs) and bacterial species in cattle raised in two different cattle production systems (grass- and grain-fed). Fecal swab samples were collected at five time points spanning pre-weaning and prior to harvest. The antibiotic resistance gene and bacterial communities were relatively similar in the pre-weaning period when cattle in both systems were milking and on pasture. Resistance genes and bacterial communities diverged post-weaning when system B cattle were given a grain diet with feed additives for growth promotion containing non-medically important antibiotics (i.e., ionophores). The levels of medically important ARGs (e.g., macrolides) increased in system B grain-fed cattle post-weaning and were higher than in system A just prior to slaughter. These data provide additional evidence that farm management strategies impact the level of antibiotic resistance.</p>","PeriodicalId":19052,"journal":{"name":"mSphere","volume":" ","pages":"e0073824"},"PeriodicalIF":3.7,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143414677","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prophages are infrequently associated with antibiotic resistance in <i>Pseudomonas aeruginosa</i> clinical isolates.","authors":"Tony H Chang, Julie D Pourtois, Naomi L Haddock, Daisuke Furukawa, Kate E Kelly, Derek F Amanatullah, Elizabeth Burgener, Carlos Milla, Niaz Banaei, Paul L Bollyky","doi":"10.1128/msphere.00904-24","DOIUrl":"10.1128/msphere.00904-24","url":null,"abstract":"<p><p>Lysogenic bacteriophages can integrate their genome into the bacterial chromosome in the form of a prophage and can promote genetic transfer between bacterial strains <i>in vitro</i>. However, the contribution of lysogenic bacteriophages to the incidence of antimicrobial resistance (AMR) in clinical settings is poorly understood. Here, in a set of 186 clinical isolates of <i>Pseudomonas aeruginosa</i> collected from respiratory cultures from 82 patients with cystic fibrosis, we evaluate the links between prophage counts and both genomic and phenotypic resistance to six anti-pseudomonal antibiotics: tobramycin, colistin, ciprofloxacin, meropenem, aztreonam, and piperacillin-tazobactam. We identified 239 different prophages in total. We find that <i>P. aeruginosa</i> isolates contain on average 3.06 ± 1.84 (SD) predicted prophages. We find no significant association between the number of prophages per isolate and the minimum inhibitory concentration for any of these antibiotics. We then investigate the relationship between particular prophages and AMR. We identify a single lysogenic phage associated with phenotypic resistance to the antibiotic tobramycin and, consistent with this association, we observe that AMR genes associated with resistance to tobramycin are more likely to be found when this prophage is present. However, we find that they are not encoded directly on prophage sequences. Additionally, we identify a single prophage statistically associated with ciprofloxacin resistance but do not identify any genes associated with ciprofloxacin phenotypic resistance. These findings suggest that prophages are only infrequently associated with the AMR genes in clinical isolates of <i>P. aeruginosa</i>.IMPORTANCEAntibiotic-resistant infections of <i>Pseudomonas aeruginosa</i> (<i>Pa</i>), a leading pathogen in patients with cystic fibrosis (CF), are a global health threat. While lysogenic bacteriophages are known to facilitate horizontal gene transfer, their role in promoting antibiotic resistance in clinical settings remains poorly understood. In our analysis of 186 clinical isolates of <i>P. aeruginosa</i> from CF patients, we find that prophage abundance does not predict phenotypic resistance to key antibiotics but that specific prophages are infrequently associated with tobramycin resistance genes. In addition, we do not find antimicrobial resistance (AMR) genes encoded directly on prophages. These results highlight that while phages can be associated with AMR, phage-mediated AMR transfer may be rare in clinical isolates and difficult to identify. This work is important for future efforts on mitigating AMR in CFCF and other vulnerable populations affected by <i>Pa</i> infections and advances our understanding of bacterial-phage dynamics in clinical infections.</p>","PeriodicalId":19052,"journal":{"name":"mSphere","volume":" ","pages":"e0090424"},"PeriodicalIF":3.7,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143409274","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Virus-induced perturbations in the mouse microbiome are impacted by microbial experience.","authors":"Shanley N Roach, Wendy Phillips, Lauren M Pross, Autumn E Sanders, Mark J Pierson, Ryan C Hunter, Ryan A Langlois","doi":"10.1128/msphere.00563-24","DOIUrl":"https://doi.org/10.1128/msphere.00563-24","url":null,"abstract":"<p><p>The bacterial microbiome has a major impact on health and can shape metabolism, host tolerance, immune responses, and the outcome of future infections. The bacterial microbiome is highly variable between individuals. Specific pathogen-free animals have reduced microbiome diversity, making it difficult to evaluate the impact of infection-induced microbiome disruption that would be observed in free-living animals, including people. Mice are commonly used as a preclinical model but unfortunately often fail to predict translation success or failure, particularly for immune and infectious disease-targeting therapies. Here, we utilize pet store mouse cohoused \"dirty\" mice with diverse microbial experience to explore how host variability and infection may be interacting to drive unique microbiome changes. We found that cohoused animals had significantly increased bacterial diversity in the small intestine and cecum but not in the large intestine. There were differentially abundant taxa between clean and dirty animals in all three tissues. After infection with influenza A virus, samples clustered by both housing condition and infection status in the cecum and large intestine, while small intestine samples clustered predominantly by infection. Altogether, these results highlight the differential impact of housing, infection, and interaction between the two in dictating community composition across the gastrointestinal microbiome.IMPORTANCETraditionally housed pathogen-free mouse models do not fully capture the natural variability observed among human microbiomes, which may underlie their poor translationally predictive value. Understanding the difference between pathogen-induced shifts in the bacterial microbiome and natural microbiome variance is a major hurdle to determining bacterial biomarkers of disease. It is also critical to understand how diverse baseline microbiomes may be differentially impacted by infection and contribute to disease. Pet store cohoused \"dirty\" mice have diverse microbial experiences and microbiomes, allowing us to evaluate how baseline variation, infection, and interaction between the two impact the microbiome.</p>","PeriodicalId":19052,"journal":{"name":"mSphere","volume":" ","pages":"e0056324"},"PeriodicalIF":3.7,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143409278","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterization of diet-linked amino acid pool influence on <i>Fusobacterium</i> spp. growth and metabolism.","authors":"Avery V Robinson, Sarah J Vancuren, Massimo Marcone, Emma Allen-Vercoe","doi":"10.1128/msphere.00789-24","DOIUrl":"https://doi.org/10.1128/msphere.00789-24","url":null,"abstract":"&lt;p&gt;&lt;p&gt;The genus &lt;i&gt;Fusobacterium&lt;/i&gt; contains multiple proteolytic opportunistic pathogens that have been increasingly linked to colorectal cancer (CRC). \"Oncomicrobes\" such as these fusobacterial species within the gut microbiota may contribute to CRC onset and/or progression. Protein-rich diets may both directly increase CRC risk and enrich for proteolytic oncomicrobes, including &lt;i&gt;Fusobacterium&lt;/i&gt; spp. Individual food substrates vary in amino acid content, and released amino acid content that is not absorbed in the small intestine may influence the growth of colonic proteolytic fermenters. Fusobacteria such as &lt;i&gt;Fusobacterium&lt;/i&gt; spp. are known to preferentially metabolize certain amino acids. As such, some foods may better support the growth of these species within the colonic environment than others. To explore this, in this study, we created free amino acid pools (FAAPs) to represent proportions of amino acids in major proteins of three common dietary protein sources (soy, beef, and bovine milk). Growth curves were generated for 39 &lt;i&gt;Fusobacterium&lt;/i&gt; spp. strains cultured in a dilute medium supplemented with each of the three FAAPs. Thereafter, amino acid use by 31 of the 39 &lt;i&gt;Fusobacterium&lt;/i&gt; spp. strains in each FAAP treatment was assessed. FAAP supplementation increased growth metrics of all &lt;i&gt;Fusobacterium&lt;/i&gt; spp. strains tested; however, the strains varied greatly in terms of the FAAP(s) generating the greatest increase in growth. Furthermore, the amino acid utilization strategy was highly variable between strains of &lt;i&gt;Fusobacterium&lt;/i&gt; spp. Neither growth metrics nor amino acid utilization could be explained by species classification of &lt;i&gt;Fusobacterium&lt;/i&gt; spp. strains. This report expands upon the previous knowledge of fusobacterial amino acid metabolism and indicates that proteolytic oncomicrobial activity should be assessed in the context of available protein sources.IMPORTANCE&lt;i&gt;Fusobacterium&lt;/i&gt; spp. including &lt;i&gt;F. animalis&lt;/i&gt;, &lt;i&gt;F. nucleatum&lt;/i&gt;, &lt;i&gt;F. vincentii&lt;/i&gt;, and &lt;i&gt;F. polymorphum&lt;/i&gt; are common oral commensals with emerging importance in diseases across multiple body sites, including CRC. CRC lesions associated with fusobacteria tend to result in poorer prognosis and increased disease recurrence. While &lt;i&gt;Fusobacterium&lt;/i&gt; spp. are thought to colonize after tumorigenesis, little is known about the factors that facilitate this colonization. Protein-rich diets yielding readily metabolized free amino acids within the colon may promote the growth of proteolytic fermenters such as fusobacteria. Here, we show that variable concentrations of free amino acids within pools that represent different dietary protein sources differentially influence fusobacterial growth, including CRC-relevant strains of &lt;i&gt;Fusobacterium&lt;/i&gt; spp. This work highlights the high degree of variation in fusobacterial amino acid utilization patterns and suggests differing proportions of dietary amino acids that reach the colon could influenc","PeriodicalId":19052,"journal":{"name":"mSphere","volume":" ","pages":"e0078924"},"PeriodicalIF":3.7,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143409348","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Abundance of clinically relevant antimicrobial resistance genes in the golden jackal (<i>Canis aureus</i>) gut.","authors":"Roi Lapid, Yair Motro, Hillary Craddock, Ikram Salah, Roni King, Katherine Winner, Gila Kahila Bar-Gal, Jacob Moran-Gilad","doi":"10.1128/msphere.00819-24","DOIUrl":"https://doi.org/10.1128/msphere.00819-24","url":null,"abstract":"<p><p>The spread of antimicrobial resistance (AMR) is a critical One Health issue. Wildlife could act as reservoirs or vehicles of AMR bacteria (ARBs) and AMR genes (ARGs) but are relatively understudied. We sought to investigate clinically relevant ARGs in golden jackals (<i>Canis aureus</i>) thriving near human settlements in Israel. Fecal samples were collected from 111 jackals across four regions over a 10-month period. Various animal and spatio-temporal metadata were collected. Samples were analyzed by quantitative PCR (qPCR) for beta-lactamases (<i>bla</i>TEM, <i>bla</i>CTX-M15, and <i>bla</i>SHV), <i>qnrS</i> and <i>int1</i>. A subset of samples was subject to shotgun metagenomic sequencing followed by resistome and microbiome analyses. qPCR detected a high prevalence of ARGs, including beta-lactamases (<i>bla</i>TEM-1, 96.4%; <i>bla</i>CTX-M-15, 51.4%, <i>bla</i>SHV, 15.3%), fluoroquinolone resistance (<i>qnrS</i>, 87.4%), and class 1 integrons (<i>Int1</i>, 94.6%). The <i>bla</i>TEM-1 gene was found to be more prevalent in adult jackals compared to younger ones. Metagenomic analysis of a subset of samples revealed a diverse gut microbiome harboring a rich resistome with tetracycline resistance genes being the most prevalent. Metagenome-assembled genome analysis further identified several ARGs associated with clinically relevant bacteria. These findings highlight the potential role of golden jackals as reservoirs for AMR and emphasize the need for ongoing surveillance to better understand AMR transmission dynamics at the wildlife-human interface.</p><p><strong>Importance: </strong>The research highlights the potential role of the golden jackals as reservoirs for antimicrobial resistance (AMR). The high prevalence of clinically relevant AMR genes in these jackals emphasizes the need for ongoing surveillance and monitoring to better understand AMR transmission dynamics at the wildlife-human interface.</p>","PeriodicalId":19052,"journal":{"name":"mSphere","volume":" ","pages":"e0081924"},"PeriodicalIF":3.7,"publicationDate":"2025-02-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143409345","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Motility-dependent processes in <i>Toxoplasma gondii</i> tachyzoites and bradyzoites: same same but different.","authors":"Robyn S Kent, Gary E Ward","doi":"10.1128/msphere.00855-24","DOIUrl":"10.1128/msphere.00855-24","url":null,"abstract":"<p><p>During infection, <i>Toxoplasma gondii</i> tachyzoites must be able to move in order to migrate through tissues, cross biological barriers, and penetrate into and egress from cells they infect. Bradyzoite-stage parasites, which establish infection in naïve hosts, also require motility to escape from cysts after they are ingested and to subsequently migrate to the gut wall, where they either invade cells of the intestinal epithelium or squeeze between these cells to infect the underlying tissue. Little is known about the motility of bradyzoites, which we analyze in detail here and compare to the well-characterized motility and motility-dependent processes of tachyzoites. Unexpectedly, bradyzoites were found to be as motile as tachyzoites in a three-dimensional model extracellular matrix, and they showed increased invasion into and transmigration across monolayers of certain cell types, consistent with their need to establish infection in the gut. The motility of the two stages was inhibited to the same extent by cytochalasin D and KNX-002, compounds known to target the parasite's actomyosin-based motor. Other compounds that impact tachyzoite motility (tachyplegin and enhancer 5) have a reduced effect on bradyzoites. Furthermore, rapid bradyzoite egress from infected cells is not triggered by treatment with calcium ionophores, as it is with tachyzoites. The similarities and differences between these two life cycle stages highlight the need to characterize both tachyzoites and bradyzoites for a more complete understanding of the role of motility in the parasite life cycle and the effect that motility-targeting therapeutics will have on disease establishment and progression.</p><p><strong>Importance: </strong><i>Toxoplasma gondii</i> is a parasite that chronically infects around one-third of the world's population. <i>Toxoplasma</i> uses motility for multiple purposes during infection, including extracellular migration, invasion into host cells, and host cell egress. These motility-dependent processes have been extensively studied in the life cycle stage responsible for acute infection, the tachyzoite. In contrast, motility and motility-dependent processes are poorly understood in bradyzoite-stage parasites, which are responsible for both establishing infection after consumption of infected meat and initiating potentially life-threatening reactivated infections in the brains of immunocompromised individuals. We show here that the motility and motility-dependent processes of bradyzoites are similar in many respects to those of tachyzoites but markedly different in others. The results of this study highlight the need to consider both life cycle stages in attempts to develop drugs targeting parasite motility and the signaling processes that regulate motility-dependent processes during infection by these important human pathogens.</p>","PeriodicalId":19052,"journal":{"name":"mSphere","volume":" ","pages":"e0085524"},"PeriodicalIF":3.7,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143399045","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Genome-scale CRISPR/Cas9 screening reveals the role of <i>PSMD4</i> in colibactin-mediated cell cycle arrest.","authors":"Michael W Dougherty, Ryan M Hoffmann, Maria C Hernandez, Yougant Airan, Raad Z Gharaibeh, Seth B Herzon, Ye Yang, Christian Jobin","doi":"10.1128/msphere.00692-24","DOIUrl":"https://doi.org/10.1128/msphere.00692-24","url":null,"abstract":"<p><p>Colibactin is a genotoxic secondary metabolite produced by certain <i>Enterobacteriaceae</i> strains that populate the intestine and produces a specific mutational signature in human colonocytes. However, the host pathways involved in colibactin response remain unclear. To address this gap, we performed genome-wide CRISPR/Cas9 knockout screens and RNA sequencing utilizing live <i>pks⁺</i> bacteria and a synthetic colibactin analog. We identified 20 enriched genes with a MAGeCK score of >2.0 in both screens, including proteasomal subunits (e.g., <i>PSMG4</i> and <i>PSMD4</i>), RNA processing factors (e.g., <i>SF1</i> and <i>PRPF8</i>), and RNA polymerase III (e.g., <i>CRCP</i>), and validated the role of <i>PSMD4</i> in colibactin sensitization. <i>PSMD4</i> knockout in HEK293T and HT-29 cells promoted cell viability and ameliorated G2-M cell cycle arrest but did not affect the amount of phosphorylated H2AX foci after exposure to synthetic colibactin 742. Consistent with these observations, <i>PSMD4</i>^-/- cells had a significantly higher colony formation rate and bigger colony size than control cells after 742 exposure. These findings suggest that <i>PSMD4</i> regulates cell cycle arrest following colibactin-induced DNA damage and that cells with <i>PSMD4</i> deficiency may continue to replicate despite DNA damage, potentially increasing the risk of malignant transformation.</p><p><strong>Importance: </strong>Colibactin has been implicated as a causative agent of colorectal cancer. However, colibactin-producing bacteria are also present in many healthy individuals, leading to the hypothesis that some aspects of colibactin regulation or host response dictate the molecule's carcinogenic potential. Elucidating the host-response pathways involved in dictating cell fate after colibactin intoxication has been difficult, partially due to an inability to isolate the molecule. This study provides the first high-throughput CRISPR/Cas9 screening to identify genes conferring colibactin sensitivity. Here, we utilize both bacterial infection and a synthetic colibactin analog to identify genes directly involved in colibactin response. These findings provide insight into how differences in gene expression may render certain individuals more vulnerable to colibactin-initiated tumor formation after DNA damage.</p>","PeriodicalId":19052,"journal":{"name":"mSphere","volume":" ","pages":"e0069224"},"PeriodicalIF":3.7,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143365287","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}