The Microbe最新文献

{"title":"Phytogenic synthesis and antimicrobial activity of ZnO nano bow ties (ZnO NBTs): An experimental and computational study","authors":"Manju Manuel ,&nbsp;M. Gomathy ,&nbsp;Manikantan Pappuswamy ,&nbsp;Krishna Bisetty ,&nbsp;Suvardhan Kanchi","doi":"10.1016/j.microb.2024.100206","DOIUrl":"10.1016/j.microb.2024.100206","url":null,"abstract":"<div><div>Phytogenic synthesis is a sustainable and eco-friendly approach for producing nanoscale particles, using biological entities such as plants and their byproducts. In this study, <em>Allium sativum</em> extract was selected as a capping and reducing agent due to the presence of phytochemicals such as allicin, diallyl disulfide (DADS), vinyl dithiins, ajoene (E- and Z-ajoene), diallyl trisulfide (DATS), and thiol (sulfhydryl) groups. The resulting ZnO Nano Bow Ties (ZnO NBTs) were characterized using FE-SEM, XRD, EDX, DLS, zeta potential, FTIR, and UV-Vis spectroscopy to evaluate the size, morphology, and crystallinity. The obtained XRD, SEM, and DLS results suggested an average longitudinal length of ∼372 nm with a maximum lateral width of ∼64 nm and a Bow Tie shape. Gas Chromatography-Mass Spectroscopy (GC-MS) analysis was employed to elucidate the prominent phytochemical constituents of the <em>Allium sativum</em> extract. Preliminary antibacterial assays reveal significant inhibition zones and growth inhibition effects against gram-negative bacteria of both <em>Klebsiella pneumoniae</em> and <em>Escherichia coli,</em> suggesting the promising antimicrobial potential of these ZnO NBTs. Monte Carlo simulations revealed that the cone-shaped ZnO NBTs bind strongly to the active sites of the target proteins with binding affinities of −36.20 and −32.14 kcal/mol for <em>Klebsiella pneumoniae</em> and <em>Escherichia coli</em> respectively, which correlates with their activities. The ZnO NBTs complexes formed stronger hydrophobic interactions and hydrogen bonds with amino acid residues of <em>Escherichia coli</em> than with <em>Klebsiella pneumoniae</em>. This integrated experimental and computational study underscores the potential of the use of ZnO NBTs as a sustainable and effective strategy to combat bacterial pathogens. The findings of this study indicate that efficient morphology (shape) is a major contributor to the protein binding affinities of ZnO NBTs, with promising implications for the design of antibacterial drugs in nanomedicine.</div></div>","PeriodicalId":101246,"journal":{"name":"The Microbe","volume":"5 ","pages":"Article 100206"},"PeriodicalIF":0.0,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142745412","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Atherosclerosis: Progression, risk factors, diagnosis, treatment, probiotics and synbiotics as a new prophylactic hope","authors":"Siloni Patial,&nbsp;Akshita Sharma,&nbsp;Khem Raj,&nbsp;Geeta Shukla","doi":"10.1016/j.microb.2024.100212","DOIUrl":"10.1016/j.microb.2024.100212","url":null,"abstract":"<div><div>Cardiovascular disease represents a significant public health challenge globally, being the foremost cause of morbidity and mortality, primarily due to atherosclerosis that occurs from the deposition of fats and fibrous elements in the walls of the artery. Approximately 90 % of cardiovascular diseases are potentially due to lifestyle-related factors such as high cholesterol, stress, high blood pressure, diabetes, and diet highlighting the importance of maintaining a healthy lifestyle. Normally, atherosclerosis is treated with statins but due to some adverse effects such as muscle pain, neuropathy, fatigue, gastrointestinal discomfort, and neurocognitive symptoms, the interest of scientists has shifted towards the use of natural interventions with conventional prophylactic agents such as phytochemicals, nutraceuticals, probiotics, and synbiotics. Among these, probiotics are considered a promising candidate due to their anti-inflammatory, anti-oxidative, immunomodulatory, and ameliorating microbiome dysbiosis in various diseases. Additionally, the combination of probiotics with prebiotics referred to as synbiotics may augment the anti-atherosclerotic potential as prebiotics enhance both the growth and metabolic processes of the probiotics. Therefore, an attempt has been made to provide insight into the detailed information on atherosclerosis, i.e., epidemiology, pathophysiology, risk factors, and diagnosis, emphasizing the prophylactic modulatory mechanisms of probiotics and synbiotics.</div></div>","PeriodicalId":101246,"journal":{"name":"The Microbe","volume":"5 ","pages":"Article 100212"},"PeriodicalIF":0.0,"publicationDate":"2024-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142745413","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Epidemiology of Plasmodium vivax malaria infection in Colombia","authors":"Mario J. Olivera ,&nbsp;Julio Cesar Padilla Rodriguez ,&nbsp;Pablo Enrique Chaparro Narváez ,&nbsp;Willian León Quevedo","doi":"10.1016/j.microb.2024.100209","DOIUrl":"10.1016/j.microb.2024.100209","url":null,"abstract":"<div><h3>Background</h3><div>Despite being preventable and curable, malaria remains a major economic and social burden, with 249 million global cases and 608,000 deaths in 2022. Although <em>Plasmodium vivax</em> cases have decreased globally, it still poses significant challenges, particularly in the Americas. In Colombia<em>, P. vivax</em> continues to be a major concern due to its wide distribution and recurrent nature. The objective of the study was to determine the temporal and spatial distribution and epidemiological behavior of <em>P. vivax</em> malaria in Colombia from 2000 to 2023<strong>.</strong></div></div><div><h3>Methods</h3><div>A comprehensive time-series study using official secondary data on malaria-associated morbidity and mortality in Colombia from 2000 to 2023. Temporal-spatial and population variables were analyzed, and the absolute and relative frequency measures of general and regional morbidity and mortality were estimated.</div></div><div><h3>Results</h3><div>Overall, <em>P. vivax</em> cases decreased, but complications, mortality, and recurrences have risen. Colombia reported 2193,233 malaria cases, with <em>P. vivax</em> causing 60.1 % (1318,820 cases). Men were notably affected, constituting 62.9 % of cases. The most vulnerable age groups were 15–29 years (36.7 %) and 5–14 years (22.9 %). The Uraba-Bajo Cauca-Sinu-San Jorge region had the highest prevalence (51.1 %). Severe malaria resulted in 15,575 complications (1.1 % of cases), with 68 % being hematological. Recurrences totalled 327,067 episodes (24.8 % recurrence rate). Epidemics were observed in 2001, 2002, 2004, 2007, 2010 and 2023, reflecting cyclical patterns.</div></div><div><h3>Conclusions</h3><div>This 24-year study of <em>P. vivax</em> in Colombia reveals a high prevalence and widespread distribution of the disease, marked by unstable and varied endemic-epidemic transmission. While overall cases have decreased, there has been a concerning rise in complications, mortality, and recurrence rates. These findings underscore persistent challenges in managing and controlling <em>P. vivax</em> malaria and highlight the need for enhanced strategies to address these ongoing issues</div></div>","PeriodicalId":101246,"journal":{"name":"The Microbe","volume":"5 ","pages":"Article 100209"},"PeriodicalIF":0.0,"publicationDate":"2024-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142705700","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Studying the effect of magnetic fields on biological activity of phycocyanin extracted from Desmonostoc alborzicum","authors":"Zahra Pish Saraei ,&nbsp;Bahareh Nowruzi ,&nbsp;Mohammad Hossein Morowvat","doi":"10.1016/j.microb.2024.100207","DOIUrl":"10.1016/j.microb.2024.100207","url":null,"abstract":"<div><div>Multiple studies have provided evidence of the positive effects of treatment with magnetic fields on the efficiency of producing secondary compounds, development, and the overall condition of cyanobacteria cultures. Therefore, the main objective of this study is to evaluate the impact of different magnetic fields (30 and 60 mT for 21 days) on the biological activity of phycocyanin (PC) extracted from <em>Desmonostoc alborzicum</em>. Results showed that a 30 mT magnetic field had increased the concentration and purity of PC. However, the highest antioxidant and antibacterial and antifungal activity was found in the PC exposed to 60 mT magnetic field (p&lt;0.05). However the results of SDS-PAGE gel showed that the amounts of alpha and beta subunits of PC treated with magnetic fields of 30 mT rose by 1.4 and 1.6 times, respectively, compared to the control. In conclusion, applying a 60 mT magnetic field could have the highest biological activity for PC in comparison to 30 mT.</div></div>","PeriodicalId":101246,"journal":{"name":"The Microbe","volume":"5 ","pages":"Article 100207"},"PeriodicalIF":0.0,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142705761","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"First detection and molecular characterization of Alistipes onderdonkii in ruminants","authors":"Kyriacos A. Hasapis ,&nbsp;Iris Charalambidou ,&nbsp;Catherine O.’Dowd Phanis ,&nbsp;Stefanie Kazamia ,&nbsp;Nicolaos Kassinis ,&nbsp;Chad Schou ,&nbsp;Panagiotis Karanis","doi":"10.1016/j.microb.2024.100205","DOIUrl":"10.1016/j.microb.2024.100205","url":null,"abstract":"<div><div><em>Alistipes onderdonkii (A. onderdonkii)</em> is a newly characterised species of bacteria that has been extensively studied in humans as a part of the normal gut microbiota; its role in gastrointestinal diseases and some types of cancer is under debate. In this study <em>A. onderdonkii</em> is detected in animal stools using PCR and sequencing of the PCR products. A total of 146 faecal samples from ruminants, precisely 32 domestic sheep (<em>Ovis aries</em>), 10 domestic and 34 free-ranging goats (<em>Capra hircus</em>) and 70 wild mouflons (<em>Ovis gmelini ophion</em>) were examined, and 2 of them were positive for <em>A. ondendonkii</em> (2/146=1.4 %), both belonging to goats (2/44=4.5 %), one belonging to a domestic goat and the second belonging to a free-ranging goat. To our knowledge, this is the first report of <em>A. onderdonkii</em> in ruminants. This study aimed to evaluate the prevalence of <em>A. onderdonkii</em> in domestic and wild small ruminants in Cyprus. More research is required to elucidate the role of <em>A. onderdonkii</em> in animal health.</div></div>","PeriodicalId":101246,"journal":{"name":"The Microbe","volume":"5 ","pages":"Article 100205"},"PeriodicalIF":0.0,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142705760","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Osteoinductive accelerating potential of myxobacterial secondary metabolites","authors":"Hamide Parhizkari ,&nbsp;Fatemeh Mohammadipanah ,&nbsp;Mahshid Hodjat","doi":"10.1016/j.microb.2024.100204","DOIUrl":"10.1016/j.microb.2024.100204","url":null,"abstract":"<div><div>The increased aging population demands improved osteoblast generation in vitro for clinical treatments. Myxobacteria synthesize a wide range of biologically active secondary metabolites with unique structural features that motivated their evaluation in this study for differentiation induction of bone marrow stem cells into osteoblasts. Calcium deposition and alkaline phosphatase (AKP) enzyme activity were quantitatively measured, and the expression of osteoblastic markers and calcium nodules was determined via alizarin red staining as differentiation markers. Results showed that a myxobacterial extract induced bone marrow stem cell differentiation by increasing AKP activity, calcium deposition, osteopontin (OPN), and osteocalcin (OCN) expression. Compared to conventional osteogenesis medium, Myxobacterium UTMC 4530 metabolite extract at 0.048 μg/ml, showed 27 % higher AKP activity, as well as 13 % and 7 % higher expression of the OCN and OPN genes, respectively. Despite ultralow concentrations, Myxobacterial extract induces a high level of differentiation, which may make it a valuable source of assessment for developing potent <em>in vitro</em> inducers of bone marrow stem cells which may have therapeutic potential in the future by promoting osteogenesis</div></div>","PeriodicalId":101246,"journal":{"name":"The Microbe","volume":"5 ","pages":"Article 100204"},"PeriodicalIF":0.0,"publicationDate":"2024-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142705759","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Could acute Q fever be causing some cases of pediatric acute encephalitis syndrome in eastern Uttar Pradesh?","authors":"Shahzadi Gulafshan,&nbsp;Pooja Bhardwaj,&nbsp;Rohit Beniwal,&nbsp;Vishal Yadav,&nbsp;Rajni Kant,&nbsp;Kamran Zaman,&nbsp;Mahim Mittal,&nbsp;Bhoopendra Sharma,&nbsp;Vijai Kumar Srivastava,&nbsp;Rajeev Singh","doi":"10.1016/j.microb.2024.100203","DOIUrl":"10.1016/j.microb.2024.100203","url":null,"abstract":"<div><h3>Purpose</h3><div>Q -fever is an underestimated zoonotic infection caused by <em>Coxiella burnetii</em> (CB). Humans are accidental host, and CB infection along with febrile illness also does neurological disorder. In India pediatric acute encephalitis syndrome (pAES) is reported very often from eastern Uttar Pradesh (E-UP), where, in 20–25 % of the cases, etiology remains unidentified. Therefore, we aim to investigate the seroprevalence for acute Q fever (AQF) among the hospitalized pAES patients, truly negative for other reported etiologies of the region by ELISA.</div></div><div><h3>Pricipal results</h3><div>Total 282 pAES cases were recruited in this study. Each case presented with fever, and vomiting. Further, a combination of one or more symptoms including headache, abnormal body movement, frothing from mouth, up-rolling eyeballs, and unconsciousness was observed in infected patients. In this study we have found 2.1 % (6/282) seroprevalence of P2 <em>Coxiella burnetii IgM in studied cases.</em></div></div><div><h3>Conclusion</h3><div>The finding would assist clinicians in appropriate diagnosis of AES cases in India. Moreover, this study suggests further surveillance for CB infection among cases with neurological disorder.</div></div>","PeriodicalId":101246,"journal":{"name":"The Microbe","volume":"5 ","pages":"Article 100203"},"PeriodicalIF":0.0,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142705699","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Temporal dynamics of the bacterial community structure and functions associated with marine sponges collected off Karah Island, Terengganu, Malaysia","authors":"Yuki Hayami ,&nbsp;Logajothiswaran Ambalavanan ,&nbsp;Sandra Catherine Zainathan ,&nbsp;Muhd Danish-Daniel ,&nbsp;Shumpei Iehata","doi":"10.1016/j.microb.2024.100202","DOIUrl":"10.1016/j.microb.2024.100202","url":null,"abstract":"<div><div>The marine sponge microbiome has been investigated for decades, yet its temporal fluctuation/stability is poorly understood. This study aimed to describe the seasonal dynamics of the bacterial composition and predicted functions associated with two tropical marine sponge species (<em>Aaptos suberitoides</em> and <em>Xestospongia testudinaria</em>) collected off Karah Island, Malaysia, in the three seasons (dry season, pre- and post-monsoon season) using 16S rRNA gene amplicon sequencing and Functional Annotation of Prokaryotic Taxa (FAPROTAX). The bacterial taxonomic structures demonstrated divergences among <em>A</em>. <em>suberitoides</em>, <em>X</em>. <em>testudinaria</em>, and seawater, regardless of seasons. Chloroflexi, Proteobacteria, Cyanobacteria, Actinobacteriota, and Acidobacteriota comprised the core bacterial communities in two marine sponge species throughout the seasons, however, there were differences in bacterial composition between the two marine sponges. In addition, <em>A</em>. <em>suberitoides</em> was enriched with Dadabacteria, Spirochaetota, and Bdellovibrionota, whereas <em>X</em>. <em>testudinaria</em> abundantly harbored Poribacteria, PAUC34f, and Anck6. At the genus level, SAR202 clade and Candidatus <em>Synechococcus spongiarum</em> group dominated marine sponge samples throughout the year. Several genera, such as SAR202 clade, Candidatus <em>Synechococcus spongiarum</em> group, and <em>Entotheonellaceae</em>, were discovered only in marine sponge samples. <em>Spirochaeta</em> and <em>Dadabacteriales</em> displayed higher relative abundances in <em>A</em>. <em>suberitoides</em>, while <em>Poribacteria</em> and PAUC34f were more abundant in <em>X</em>. <em>testudinaria</em>. SAR202 clade was positively correlated with dissolved oxygen (DO), pH, phosphate, and ammonia in <em>A</em>. <em>suberitoides</em>. Likewise, Candidatus <em>Synechococcus spongiarum</em> group was negatively correlated with salinity and nitrate in <em>X</em>. <em>testudinaria</em>. Predicted functions by FAPROTAX annotated the phototrophic-related functions in both marine sponges, which might be attributed to a sponge-specific taxon Candidatus <em>Synechococcus spongiarum</em> group. The functions “predatory or exoparasitic” and “fermentation” were highly detected in <em>A</em>. <em>suberitoides</em>, which might be related to the bacterial genera <em>Bdellovibrio</em> and <em>Spirochaeta</em>, respectively. This study guides a deep understanding of the bacterial community structures associated with tropical marine sponges and their temporal behavior.</div></div>","PeriodicalId":101246,"journal":{"name":"The Microbe","volume":"5 ","pages":"Article 100202"},"PeriodicalIF":0.0,"publicationDate":"2024-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142655686","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Green Synthesis of silver nanoparticles from clematis gouriana leaf extract: Physicochemical characterization and antibacterial activity determination for treatment of blood stream infections","authors":"Vinayak Yadav ,&nbsp;Sunil T. Galatage ,&nbsp;Arehalli S. Manjappa ,&nbsp;Ahmad Salawi ,&nbsp;Malleswara Rao Peram ,&nbsp;Sameer J. Nadaf ,&nbsp;Swapnil S. Harale","doi":"10.1016/j.microb.2024.100197","DOIUrl":"10.1016/j.microb.2024.100197","url":null,"abstract":"<div><h3>Background</h3><div>The global incidence of bloodstream infections (BSIs) is rising, necessitating the development of effective therapeutic strategies to achieve complete eradication. This study focuses on the synthesis of silver nanoparticles (AgNPs) functionalized with <em>Clematis gouriana</em> extract (CG) (CG-AgNPs) as a potential alternative to conventional treatments for combating BSIs caused by bacterial pathogens.</div></div><div><h3>Methods</h3><div>AgNPs were synthesized by reducing silver nitrate (AgNO₃) using CG extract. The formation of CG-AgNPs was confirmed through UV-Vis spectroscopy, while their characterization included the determination of mean particle size and zeta potential. Elemental composition was analyzed using energy-dispersive X-ray (EDX) spectroscopy. The <em>in vitro</em> antibacterial efficacy of CG-AgNPs was assessed through multiple assays, including a time-kill assay, a film bioadhesion assay, and measurement of reactive oxygen species (ROS) generation.</div></div><div><h3>Results</h3><div>SPR (surface plasmon resonance) has been employed to validate the development of AgNPs by observing a colour shift to dark brown. The mean particle size and zeta potential of the CG-AgNPs were found to be 38 ± 2 nm (PDI 0.104 ± 0.03) and −31.2 ± 1.4 mV, respectively. Additionally, E-XRD results show that the prepared AgNPs comply with the silver presence. The minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) of the CG-AgNPs against <em>Staphylococcus aureus</em> (<em>S. aureus</em>) were observed to be 6.25 ± 0.8 µg/mL and 13.5 ± 2.4 µg/mL, respectively.Similarly, the MIC and MBC of CG-AgNPs against <em>Escherichia coli</em> (<em>E. coli</em>) were found to be 13.5 ± 1.5 μg/mL and 26 ± 2.8 μg/mL, respectively. CG-AgNPs also prevented biofilm formation and bacterial adhesion in a dose-dependent manner; 100 % inhibition was achieved in 48 h at MBC. In addition, CG-AgNPs remarkably escalated the ROS level within cells, indicating their mechanism of antimicarobial activity.</div></div><div><h3>Conclusions</h3><div>The findings of this study demonstrate that CG-AgNPs synthesized via green synthesis exhibit significant antibacterial activity, highlighting their potential as an effective alternative for the treatment of BSIs. However, further <em>in vivo</em> studies are required to optimize a suitable dosage form and validate their therapeutic efficacy against bacterial infections in clinical settings.</div></div>","PeriodicalId":101246,"journal":{"name":"The Microbe","volume":"5 ","pages":"Article 100197"},"PeriodicalIF":0.0,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142655685","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Deciphering FUR-regulated gene networks in Klebsiella pneumoniae using FUR knockout mutant","authors":"Purvi Joshi ,&nbsp;Reetu Maindolia ,&nbsp;Dhanshree Dhakre,&nbsp;Twinkle Patel,&nbsp;Devarshi Gajjar","doi":"10.1016/j.microb.2024.100201","DOIUrl":"10.1016/j.microb.2024.100201","url":null,"abstract":"<div><div><em>Klebsiella pneumoniae</em> is a nosocomial pathogen causing life-threatening infections worldwide. It possesses many virulence properties and the ferric uptake regulator (FUR) is the transcription factor that regulates the expression of various genes in <em>K. pneumoniae</em>. FUR binds to a conserved 19 bp sequence, called the FUR box, for either positive or negative regulation of the gene. FUR alters gene expression according to iron availability and also participates in virulence, colonization &amp; toxin secretion in <em>K. pneumoniae</em>. FUR deletion mutant is an interesting model to understand the virulence factors. In the present study, we identified the genes containing putative FUR boxes (&gt;50 % sequence homology) from the genome of <em>K. pneumoniae</em> M33. FUR deletion mutant for <em>K. pneumoniae</em> M33 was created using lambda red recombinase system using the plasmids- pACBSR-hyg, pMDIAI, and pFLP-hyg. The mutant (M33∆FUR) was characterized using various assays like CAS assay, string test, crystal violet assay to access siderophore production, capsule synthesis and biofilm formation respectively. FUR box was present upstream of 18 genes with distinct functions. In the FUR knockout mutant, M33∆FUR an increase in expression of iron transport and siderophore related genes <em>feoC, fhuA, fepB and fes</em> was observed whereas genes <em>feoA, cirA, fecA, fepA</em> and <em>entC</em> were down-regulated. Genes related to biofilm (<em>fimA</em> and <em>mrkD</em>) were downregulated whereas genes related to capsular polysaccharide (<em>rcsA</em> and <em>rcsB</em>) were upregulated upon FUR deletion. Among other genes <em>murG</em> and <em>sucA</em> were downregulated and <em>priB</em> and <em>srlB</em> were upregulated upon FUR deletion. This study shows that FUR regulates many genes involved in virulence, either positively or negatively.</div></div>","PeriodicalId":101246,"journal":{"name":"The Microbe","volume":"5 ","pages":"Article 100201"},"PeriodicalIF":0.0,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142655684","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}