BMC Microbiology最新文献

{"title":"One-step, rapid, nanoparticle-based biosensor platform for the simultaneous identification of hepatitis B virus and hepatitis C virus in clinical applications.","authors":"Xu Chen, Yuanfang Shi, Qi Zhao, Yu Wang, Xinggui Yang, Yan Tan, Yi Wang, Shilei Dong, Zhenghua Xiao","doi":"10.1186/s12866-024-03610-z","DOIUrl":"10.1186/s12866-024-03610-z","url":null,"abstract":"<p><strong>Objectives: </strong>Viral hepatitis caused by hepatitis B virus (HBV) and hepatitis C virus (HCV) infections remain a major global public health challenge, particularly in low- and middle-income countries. It is crucial to utilize a pointof-care (POC) testing platform that is sensitive, specific, rapid, and user-friendly for screening and diagnosis of the two infections. Here, a novel molecular diagnostic assay, integrating multiplex loop-mediated isothermal amplification with a gold nanoparticle-based lateral flow biosensor (mLAMP-AuNPs-LFB) was developed and applied for one-step, visual, rapid, sensitive, and specific identification of HBV and HCV.</p><p><strong>Methods: </strong>The AuNPs-based LFB was devised and constructed for the simultaneous detection of HBV and HCV. The HBV-LAMP and HCV-LAMP primers were designed against the S and 5'-untranslated region (5'-UTR) genes from the major HBV genotypes (B, C, D, B/C recombinant, and C/D recombinant) and HCV subtypes (1b, 2a, 3a, 3b, and 6a) in China, respectively. Our assay conditions, both multiplex-LAMP amplification temperature and time were optimized. The sensitivity and specificity of our assay were tested, and the feasibility of our assay was verified through clinical samples.</p><p><strong>Results: </strong>The AuNPs-based LFB used here was successfully manufactured according to our devise manual. The two unique independent primer pairs were successfully designed based on the S and 5'-UTR genes, respectively. The optimal mLAMP-AuNPs-LFB detection process, involving rapid nucleic acid isolation (10 min), mLAMP (63 °C for 35 min), and visual AuNPs-LFB interpretation (less than 2 min), could be completed within 50 min. The HBV&HCV-mLAMP-AuNPs-LFB assay can detect the target genes (HBV-S and HCV-5'-UTR) with as low as 20 copies of plasmid template per test, and the specificity was 100% for the experimental pathogens.</p><p><strong>Conclusions: </strong>The preliminary results manifested that our mLAMP-AuNPs-LFB assay is a valuable tool and has tremendous potential as a POC testing approach for HBV and HCV identification, especially in undeveloped regions.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142590065","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":"Isolation and characterization of non-rhizobial bacteria and arbuscular mycorrhizal fungi from legumes.","authors":"Mohamed Hemida Abd-Alla, Nivien A Nafady, Amany A Hassan, Shymaa R Bashandy","doi":"10.1186/s12866-024-03591-z","DOIUrl":"10.1186/s12866-024-03591-z","url":null,"abstract":"<p><p>This study investigates non-rhizobial endophytic bacteria in the root nodules of chickpea (Cicer arietinum L), faba bean (Vicia faba), and cowpea (Vigna unguiculata L. Walp), as well as arbuscular mycorrhizal fungi in the rhizospheric soil of chickpea and faba bean. Out of the 34 endophytic bacterial populations examined, 31 strains were identified as non-rhizobial based on nodulation tests. All strains were assessed for their plant growth-promoting (PGP) activities in vitro. The results revealed that most isolates exhibited multiple PGP activities, such as nitrogen fixation, indole-3-acetic acid (IAA) and ammonia (NH₃) production, phosphate solubilization, and exopolysaccharide production. The most effective PGP bacteria were selected for 16S rRNA analysis. Additionally, a total of 36 species of native arbuscular mycorrhizal fungi (AMF) were identified. Acaulospora (100%) and Scutellospora (91.66%) were the most prevalent genera in Cicer arietinum L. and Vicia faba L. plants, respectively. Acaulospora also exhibited the highest spore density and relative abundance in both plants. Moreover, the root colonization of Cicer arietinum L. and Vicia faba L. plants by hyphae, vesicles, and arbuscules (HVA) was significant. The findings of this study provide valuable insights into non-rhizobial endophytic bacteria associated with legume root nodules and the diversity of AMF. These organisms have great potential for PGP and can be manipulated by co-inoculation with rhizobia to enhance their biofertilizer effectiveness. This manipulation is crucial for promoting sustainable agriculture, improving crop growth, and advancing biofertilizer technology.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142590049","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":"A comparison of male and female renal pelvis urobiome of unilateral stone formers using 2bRAD-M.","authors":"Sen-Yuan Hong, Lin-Tao Miao, Yuan-Yuan Yang, Shao-Gang Wang","doi":"10.1186/s12866-024-03618-5","DOIUrl":"10.1186/s12866-024-03618-5","url":null,"abstract":"<p><strong>Background: </strong>Urolithiasis is a prevalent urological ailment characterized by increasing prevalence and recurrence rates, resulting in substantial social and economic burden. While men exhibit an incidence rate nearly twice that of women, this gender disparity is gradually diminishing. Nevertheless, the mechanisms underlying this condition remain incompletely elucidated. The identification of the urinary microbiome (urobiome) has provided a fresh perspective on urolithiasis. This study aimed to analyze the urobiome of unilateral stone formers in the renal pelvis and evaluate the variations in microbial diversity and community composition between males and females.</p><p><strong>Methods: </strong>Renal pelvis urine samples were obtained from a cohort of 21 male and 9 female patients and subsequently subjected to taxonomic and functional analysis using 2bRAD sequencing for Microbiome (2bRAD-M). The collected samples were categorized into four distinct groups, namely the stone side of males (SM), stone side of females (SF), non-stone side of males (NSM), and non-stone side of females (NSF).</p><p><strong>Results: </strong>Through the application of beta diversity analysis, dissimilarity was observed between NSM and NSF. Additionally, NSF exhibited a higher abundance of microbial populations, and a total of 29 distinct species were identified as differentially present between NSM and NSF using LEfSe. Lactobacillus iners, Atopobium deltae, Lawsonella clevelandensis, and Meyerozyma guilliermondii exhibited enrichment in the SF group compared to the SM group. Furthermore, we identified distinct species that differed between the SM and NSM groups, as well as the SF and NSF groups. Besides, we conducted COG annotation and KEGG pathway predictions, revealing significant differences in urobiome function across the different groups.</p><p><strong>Conclusion: </strong>Variations in microbial community composition and predicted functions were observed among the various groups. Future research could potentially leverage the urobiome to personalize urolithiasis treatment based on individual microbial characteristics, taking into account gender-specific differences.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142590028","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":"Exploring the lipids, carotenoids, and vitamins content of Rhodotorula glutinis with selenium supplementation under lipid accumulating and growth proliferation conditions.","authors":"Nora Elfeky, Aya Rizk, Mohamed M Gharieb","doi":"10.1186/s12866-024-03585-x","DOIUrl":"10.1186/s12866-024-03585-x","url":null,"abstract":"&lt;p&gt;&lt;strong&gt;Background: &lt;/strong&gt;Rhodotorula glutinis, a specific type of yeast, has been recognised as a superior resource for generating selenium-enriched biomass that possesses exceptional nutritional and functional attributes. The purpose of this investigation was to assess the effect of sodium selenite at different concentrations on lipid and carotenoid synthesis, as well as the growth of R. glutinis.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Methods: &lt;/strong&gt;The lipid's fatty acid composition was determined using gas chromatography (GC). The vitamins were detected by high-performance liquid chromatography (HPLC). Transmission electron microscopy was used to detect the structural modification of yeast cells caused by the addition of sodium selenite to the growth medium, as well as the accumulation of elemental selenium in the yeast cells.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Results: &lt;/strong&gt;The yeast cells demonstrated the ability to endure high concentrations of sodium selenite under lipid accumulation (LAM) and growth-promoting (YPD) conditions. 25.0 mM and 30.0 mM, respectively, were published as the IC50 values for the LAM and YPD conditions. In both growth media, 1 mM sodium selenite boosted lipid synthesis. Lipid accumulation increased 26% in LAM to 11.4 g/l and 18% in YPD to 4.3 g/l. Adding 1 mM and 3 mM sodium selenite to YPD medium increased total and cellular carotenoids by 22.8% (646.7 µg/L and 32.12 µg/g) and 48.7% (783.3 µg/L and 36.43 µg/g), respectively. Palmitic acid was identified as the most abundant fatty acid in all treatments, followed by oleic acid and linoleic acid. The concentrations of water soluble vitamins (WSV) and fat soluble vitamins (FSV) were generally significantly increased after supplementation with 1.0 mM sodium selenite. TEM examination revealed a significant reduction in lipid bodies accumulation in the yeast cells when sodium selenite was added to lipid-promoting environments. This decline is accompanied by an augmentation in the formation of peroxisomes, indicating that selenium has a direct impact on the degradation of fatty acids. In addition, autophagy appears to be the primary mechanism by which selenium ions are detoxified. Additionally, intracellular organelles disintegrate, cytoplasmic vacuolization occurs, and the cell wall and plasma membrane rupture, resulting in the discharge of cytoplasmic contents, when a high concentration of sodium selenite (20.0 mM) is added. Also, the presence of numerous electron-dense granules suggests an intracellular selenium-detoxification pathway.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Conclusion: &lt;/strong&gt;This study proposes the use of YPD with 1 mM sodium selenite to cultivate selenium-enriched biomass from R. glutinis. This approach leads to heightened lipid levels with higher accumulation of oleic, linoleic and linolenic acids, carotenoids, and vitamins. Hence, this biomass has the potential to be a valuable additive for animal, fish, and poultry feed. Furthermore, explain certain potential factors that indicate the impact of selen","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142590030","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":"Integrated control of Fusarium wilt in banana by Bacillus velezensis EB1 and potassium sorbate.","authors":"Siwen Liu, Wenlong Yang, Xiaofang Yang, Ronggao Gong, Dandan Xiang, Chunyu Li","doi":"10.1186/s12866-024-03549-1","DOIUrl":"10.1186/s12866-024-03549-1","url":null,"abstract":"<p><p>Fusarium wilt of banana, caused by Fusarium oxysporum f. sp. cubense tropical race 4 (Foc TR4), is a widely distributed soilborne disease that poses a serious threat to banana production. Many control measures have been implemented but have not been effective. Here, we evaluated a combined strategy for Fusarium wilt control that involves a biological agent (Bacillus velezensis strain EB1) and a bioactive compound (potassium sorbate). Our results showed that potassium sorbate inhibited Foc TR4 in a dose-dependent manner. Potassium sorbate did not limit the growth of EB1 in vitro; instead, it promoted the growth and antagonistic ability of EB1 by upregulating the expression of antagonism-related genes. In greenhouse experiments, the combined application of EB1 and potassium sorbate significantly reduced the disease index of Fusarium wilt by suppressing fungal growth in the roots and promoting plant growth. Overall, our results demonstrated that potassium sorbate and B. velezensis EB1 can be used together for the sustainable management of banana Fusarium wilt.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142590033","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":"Faecal carriage of extended-spectrum beta-lactamase and carbapenemase-producing enterobacterales among HIV patients at Jimma Medical Center, Southwest Ethiopia.","authors":"Dechasa Befikadu, Rahel Tamrat, Aster Wakjira Garedo, Getenet Beyene, Esayas Kebede Gudina, Mulatu Gashaw","doi":"10.1186/s12866-024-03596-8","DOIUrl":"10.1186/s12866-024-03596-8","url":null,"abstract":"<p><strong>Background: </strong>Enterobacterales infections in immunocompromised individuals are associated with considerable morbidity, mortality, and health care costs. This study aimed to assess the faecal carriage of extended-spectrum β-lactamase (ESBL) and carbapenemase-producing Enterobacterales (CPE) among HIV-infected patients at Jimma Medical Center. A total of 344 stool samples were collected and inoculated on Mac-Conkey and Eosin-Methylene Blue agar and incubated at 35-37 °C aerobically. ESBL and carbapenemase production were detected using D68C ESBL/AmpC and D73C CARBA plus (Mast Group, UK).</p><p><strong>Results: </strong>A total of 376 Enterobacterales were isolated. The prevalence of ESBL-PE and CPE carriage rate was 13.3% (50/376) and 4.3% (16/376) respectively. The highest proportion of ESBL producing isolates were found in K. pneumoniae 29.0% (9/31) followed by E. coli 13.4% (39/292). Similarly, K. pneumoniae 12.9% (4/31) was the most common carbapenem-resistant isolate followed by E. coli 3.8% (11/292). Multi-drug resistance was observed in 66.5% (250/376) of the isolates. Prior cephalosporin use (AOR = 7.9; 2.31-27.29), CD4 count (≤ 350 cells/µL) (AOR = 3.8; 1.12-12.9), and comorbidities (AOR = 2.3; 1.24-4.32) were significantly associated with ESBL production. Additionally, cephalosporin use (AOR = 6.34; 1.27-31.66) was significantly associated with the presence of CRE.</p><p><strong>Conclusions: </strong>This study revealed a high prevalence of ESBL-PE and CPE among HIV patients, with K. pneumoniae and E. coli being the dominant isolates. MDR was common, with key risk factors being prior cephalosporin use, low CD4 counts, and comorbidities. These findings emphasize the need for enhanced infection prevention and control, regular screening, and improved antibiotic stewardship to curb the spread of resistant bacteria in immunocompromised individuals.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142590031","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":"Gamma-irradiated copper-based metal organic framework nanocomposites for photocatalytic degradation of water pollutants and disinfection of some pathogenic bacteria and fungi.","authors":"Gharieb S El-Sayyad, Ahmed M El-Khawaga, Huda R M Rashdan","doi":"10.1186/s12866-024-03587-9","DOIUrl":"10.1186/s12866-024-03587-9","url":null,"abstract":"&lt;p&gt;&lt;strong&gt;Background: &lt;/strong&gt;Although there are many uses for metal-organic framework (MOF) based nanocomposites, research shows that these materials have received a lot of interest in the field of water treatment, namely in the photodegradation of water contaminants, and disinfection of some pathogenic bacteria and fungi. This is brought on by excessive water pollution, a lack of available water, low-quality drinking water, and the emergence of persistent micro-pollutants in water bodies. Photocatalytic methods may be used to remove most water contaminants, and pathogenic microbes, and MOF is an excellent modifying and supporting material for photocatalytic degradation.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Methods: &lt;/strong&gt;This work involved the fabrication of a unique Cu-MOF based nanocomposite that was exposed to gamma radiation. The nanocomposite was subsequently employed for photocatalytic degradation and as an antimicrobial agent against certain harmful bacteria and fungi. The produced Cu-MOf nanocomposite was identified by XRD, SEM, and EDX. Growth curve analysis, UV lighting impact, and antibiofilm potential have been carried out to check antimicrobial potential. Additionally, the membrane leakage test was used to determine the mechanism of the antimicrobial action. In an experimental investigation of photocatalytic activity, a 50 mL aqueous solution including 10.0 ppm of Rhodamine B (RB) was used to solubilize 10 mg of Cu-MOF. It has been investigated how pH and starting concentration affect RB elimination by Cu-MOF. Ultimately, RB elimination mechanism and kinetic investigations have been carried out.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Results: &lt;/strong&gt;SEM images from the characterization techniques demonstrated the fact that the Cu-MOF was synthesized effectively and exhibited the Cu-MOF layers' flake-like form. Uneven clusters of rods make up each stratum. The primary peaks in the Cu-MOF's diffraction pattern were found at 2θ values of 8.75&lt;sup&gt;◦&lt;/sup&gt;, 14.83&lt;sup&gt;◦&lt;/sup&gt;, 17.75&lt;sup&gt;◦&lt;/sup&gt;, 21.04&lt;sup&gt;◦&lt;/sup&gt;, 22.17&lt;sup&gt;◦&lt;/sup&gt;, 23.31&lt;sup&gt;◦&lt;/sup&gt;, 25.41&lt;sup&gt;◦&lt;/sup&gt;, and 26.38&lt;sup&gt;◦&lt;/sup&gt;, according to the XRD data. After 135 min of UV irradiation, only 8% of RB had undergone photolytic destruction. On the other hand, the elimination resulting from adsorption during a 30-min period without light was around 16%. Conversely, after 135 min, Cu-MOF's photocatalytic breakdown of RB with UV light reached 81.3%. At pH 9.0, the greatest removal of RB at equilibrium was found, and when the amount of photocatalyst rose from 5 to 20 mg, the removal efficiency improved as well. The most sensitive organism to the synthesized Cu-MOF, according to antimicrobial data, was Candida albicans, with a documented MIC value of 62.5 µg mL&lt;sup&gt;-1&lt;/sup&gt; and antibacterial ZOI as 32.5 mm after 1000 ppm treatment. Cu-MOF also showed the same MIC (62.5 µg mL&lt;sup&gt;-1&lt;/sup&gt;) values against Staphylococcus aureus and Escherichia coli, and 35.0 and 32.0 mm ZOI after 1000 ppm treatment, respectively. Ultimately","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142590032","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":"Lactobacillus rhamnosus modulates murine neonatal gut microbiota and inflammation caused by pathogenic Escherichia coli.","authors":"Hao Xuan, Shahid Umar, Cuncong Zhong, Wei Yu, Ishfaq Ahmed, Joshua L Wheatley, Venkatesh Sampath, Susana Chavez-Bueno","doi":"10.1186/s12866-024-03598-6","DOIUrl":"10.1186/s12866-024-03598-6","url":null,"abstract":"<p><strong>Background: </strong>Pathogenic Escherichia coli strains produce neonatal septicemia after colonizing the neonatal gut. While the probiotic Lactobacillus rhamnosus GG (LGG) effectively reduces neonatal sepsis, LGG's effects on the neonatal intestinal microbiota alterations and inflammation triggered by E. coli are incompletely understood. We hypothesized that LGG significantly modulates the specific neonatal gut microbial populations changes and the inflammatory response elicited by the enteral introduction of septicemia-producing E. coli. To test this hypothesis, newborn rats were pretreated orally with LGG or placebo prior to infection with the neonatal E. coli septicemia clinical isolate SCB34. Amplicon 16S rRNA gene sequencing was performed on intestinal samples. Intestinal injury and expression of inflammatory mediators and apoptosis were determined.</p><p><strong>Results: </strong>Alpha diversity of gut microbiota was greater in SCB34-infected pups in comparison to sham-infected pups, these changes were not modified by LGG pretreatment. Beta diversity analyses also showed differences between SCB34-infected vs. uninfected pups. LGG pretreatment before SCB34 infection did not result in significant beta diversity changes compared to placebo. Moreover, individual genera and species abundance analyses by linear discriminant analysis effect size (LEfSe) showed significant changes in Gram-negative, Gram-positive, and anaerobic populations resulting from LGG pretreatment and SCB34 infection. LGG significantly suppressed the expression of inflammatory cytokines but did not attenuate SCB34-induced apoptosis or histologic injury.</p><p><strong>Conclusions: </strong>LGG modulates clinically significant microbiota features and inflammation triggered by pathogenic E. coli intestinal infection shortly after birth. This new knowledge can potentially be harnessed to design novel interventions against gut-derived neonatal sepsis.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142590050","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":"VBNC Cronobacter sakazakii survives in macrophages by resisting oxidative stress and evading recognition by macrophages.","authors":"Yuanyuan Liu, Jingfeng Zhang, Haoqing Zhao, Feifeng Zhong, Jianyu Li, Lichao Zhao","doi":"10.1186/s12866-024-03595-9","DOIUrl":"10.1186/s12866-024-03595-9","url":null,"abstract":"<p><p>Survival in host macrophages is an effective strategy for pathogenic bacterial transmission and pathogenesis. Our previous study found that viable but non-culturable (VBNC) Cronobacter Sakazakii (C. sakazakii) can survive in macrophages, but its survival mechanism is not clear. In this study, we investigated the possible mechanisms of VBNC C. sakazakii survival in macrophages in terms of environmental tolerance within macrophages and evasion of macrophages recognition. The results revealed that VBNC C. sakazakii survived under oxidative conditions at a higher rate than the culturable C. sakazakii. Moreover, the stringent response gene (relA and spoT) and the antioxidant-related genes (sodA, katG, and trxA) were up-regulated, indicating that VBNC C. sakazakii may regulate antioxidation through stringent response. On the other hand, compared with culturable C. sakazakii, VBNC C. sakazakii caused reduced response (Toll-like receptor 4) in macrophages, which was attributed to the suppression of biosynthesis of the lipopolysaccharides (LPS). Furthermore, we found that ellagic acid can reduce the survival rate of bacteria in macrophages by improving the immune TLR4 recognition ability of macrophages. In conclusion, VBNC C. sakazakii may survive in macrophages by regulating oxidative tolerance through stringent response and altering LPS synthesis to evade TLR4 recognition by macrophages, which suggests the pathogenic risk of VBNC C. sakazakii.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142590066","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":"Rhizosphere bacterial community is mainly determined by soil environmental factors, but the active bacterial diversity is mainly shaped by plant selection.","authors":"Yalong Xu, Jingjing Li, Chan Qiao, Jinchu Yang, Juan Li, Xueao Zheng, Chen Wang, Peijian Cao, Yan Li, Qiansi Chen","doi":"10.1186/s12866-024-03611-y","DOIUrl":"10.1186/s12866-024-03611-y","url":null,"abstract":"<p><strong>Background: </strong>The assembly of the rhizosphere community, even the diazotroph community, is mainly shaped by soil environmental factors (including soil climate and physiochemical characteristics) and plant selection. To better understand the driving forces on the active overall and nitrogen-fixing bacterial community compositions, we characterized the communities of tobacco rhizosphere soil collected from three sampling sites with a large geographic scale (> 600 km).</p><p><strong>Results: </strong>The results indicate that the diversity and community composition of the overall bacterial and diazotroph communities are obviously differed according to the sampling sites. Still, no significant difference is found between the communities in rootzone and rhizosphere samples. Climate variables including mean annual precipitation (MAP) and mean annual temperature (MAT), soil physiochemical characteristics including available nitrogen (AN), available potassium (AK) and pH are main factors that affect the bacterial and diazotroph community structures in the three sampling sites. Furthermore, MAP and MAT, AN and available phosphorus (AP), total nitrogen (TN) and organic carbon (OC), AK and electrical conductivity (EC) showed similar effects, but pH showed independent effect on the composition of the overall bacteria and diazotroph communities. However, the alpha diversity indices of active overall and nitrogen-fixing bacteria in the rhizosphere are obviously higher than in the rootzone samples, and no significant differences are observed among different sampling sites. Proteobacteria is the predominant active phylum of all samples for overall and nitrogen-fixing bacteria. Escherichia-Shigella, Achromobacter, Streptomyces and Sphingomonas are the dominant active bacterial genera, and Bradyrhizobium, Skermanella and Extensimonas are dominant active nitrogen-fixing bacteria genera in rhizosphere. Furthermore, the high active abundance of Escherichia-Shigella but low abundance of Ralstonia in all three sampling sites indicate high root-knot nematode infection and low wilt disease endemic risk.</p><p><strong>Conclusion: </strong>These results indicate that soil environmental factors contribute more to the tobacco rhizosphere bacterial community assemblage, but the rhizosphere contributes more to the diversity of active overall bacteria and nitrogen-fixing bacteria in the community. Our study provides novel knowledge for the assemble of rhizosphere bacterial and active bacteria communities across a large geographical scale.</p>","PeriodicalId":9233,"journal":{"name":"BMC Microbiology","volume":null,"pages":null},"PeriodicalIF":4.0,"publicationDate":"2024-11-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11536854/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142582118","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}