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Shouche, Y. S.

Publications and source records attributed to Shouche, Y. S..

10 recordsLinked to original sources

Functional antagonistic interactions and genomic insights into the biosynthetic potential of human gut-derived microbiota

Concerning the biological interactions within the gut microbiome, the specialized small molecules encoded by commensal microbes mediate distinct functional aspects. However, the landscape of antagonistic interactions mediated by specialized strains and their small molecules broadly remains. Here, we sought to evaluate antimicrobial interactions as a defensive contributor to gain new insights into structure-related functions or to bring the therapeutic potential of derived molecules. We elucidated the antagonistic landscape within a collection of 330 human-gut-derived commensal microbial strains cultivated from healthy human subjects. We characterized potential antagonistic strains and found a strain-specific selective inhibition contrary to common antimicrobial drugs that wipe out a broad range of species usually found in environmental microbes. Using functional and genomic approaches for accessing biologically active natural product molecules, we identified significant biosynthetic gene clusters (BGCs) encoding the important compound families in representative gut strains which contribute to antagonistic activities and are important in host defense or maintaining homeostasis in the gut. The subsets of the BGCs were represented in metagenomics sequencing data from healthy individuals. The cell culture secretome of strains revealed potential biomarkers linked to hallmark pathways. Together, these microorganisms encode biosynthetic novelty and represent a source of biologically significant natural products important in developing new treatments for infectious diseases to cut the usage of broad-spectrum antibiotics and represent a way to combat antimicrobial resistance. Consortia of such strains can be utilized as an option for precise editing of the microbiomes or fine-tuning the microbiota-modulating therapies.

microbiology↗

A new competitive strategy to unveil the antibiotic-producing Actinobacteria

The bacterial phylum Actinobacteria encompasses microorganisms with incomparable metabolic versatility and deep resource of medicines. However, the recent decrease in the discovery rate of antibiotics warrants innovative strategies to harness actinobacterial resources for lead discovery. Indeed, microbial culturing efforts measuring the outcomes of specific genera lagged behind the detected microbial potential. Herein, we used a distinct competitive strategy that exploits competitive microbial interactions to accelerate the diversification of strain libraries producing antibiotics. This directed-evolution-based strategy shifted the diversity of Actinobacteria over the experimental time course (0-8 days) and led to the isolation of Actinobacterial strains with distinct antimicrobial spectrum against pathogens. To understand the competitive interactions over experimental time, the metagenomic community sequencing revealed that actinobacterial members from families Nocardiaceae and Cellulomonadaceae with relatively increased abundances towards end, are thus competitively advantageous. Whilst comparing the Actinobacteria retrieved in the competitive strategy to that of the routinely used isolation method, the Actinobacteria genera identified from competitive communities differed relatively in abundances as well as antimicrobial spectrum compared to actinobacterial strains retrieved in classical method. In sum, we present a strategy that influences microbial interactions to accelerate the likelihood of potential actinobacterial strains with antimicrobial potencies.

microbiology↗

Screening of tomato seed bacterial endophytes for antifungal activity reveals lipopeptide producing Bacillus siamensis as a potential bio-control agent

The current study investigates the diversity pattern and fungicidal potential of bacterial endophytes isolated from two different organic varieties of tomato plants (V1 and V2). A total of seventy-four bacterial isolates identified by 16S rRNA sequencing revealed a single genus Bacillus with 16 different species. The Shannon diversity H (1.45), Simpsons index of diversity (0.9), Magalef index (2.1), Evenness (0.96), and Species richness (8) indicated the high endophytic bacterial diversity in the V1 variety of the tomato. Bacterial endophytes isolated from both the varieties were screened for their antifungal activity against five economically critical fungal pathogens (viz., Botrytis cinerea, Rhizoctonia solani, Fusarium solani, Verticillium lateritium, and Alternaria solani) of tomato crop through dual culture assay. The data revealed B. siamensis KCTC 13613(T) as the most potent antagonist significantly (p < 0.05), inhibiting the mycelial growth between 75 to 90% against selected fungal pathogens. High bioactivity of lipopeptide extract of B. siamensis was recorded against R. solani with IC50 value of 72 ppm. The UPLC-HDMS analysis of this lipopeptide extract revealed the presence of, Surfactin and Bacillomycin D.

microbiology↗

PAN-INDIA 1000 SARS-CoV-2 RNA Genome Sequencing Reveals Important Insights into the Outbreak

The PAN-INDIA 1000 SARS-CoV-2 RNA Genome Sequencing Consortium has achieved its initial goal of completing the sequencing of 1000 SARS-CoV-2 genomes from nasopharyngeal and oropharyngeal swabs collected from individuals testing positive for COVID-19 by Real Time PCR. The samples were collected across 10 states covering different zones within India. Given the importance of this information for public health response initiatives investigating transmission of COVID-19, the sequence data is being released in GISAID database. This information will improve our understanding on how the virus is spreading, ultimately helping to interrupt the transmission chains, prevent new cases of infection, and provide impetus to research on intervention measures. This will also provide us with information on evolution of the virus, genetic predisposition (if any) and adaptation to human hosts. One thousand and fifty two sequences were used for phylodynamic, temporal and geographic mutation patterns and haplotype network analyses. Initial results indicate that multiple lineages of SARS-CoV-2 are circulating in India, probably introduced by travel from Europe, USA and East Asia. A2a (20A/B/C) was found to be predominant, along with few parental haplotypes 19A/B. In particular, there is a predominance of the D614G mutation, which is found to be emerging in almost all regions of the country. Additionally, mutations in important regions of the viral genome with significant geographical clustering have also been observed. The temporal haplotype diversities landscape in each region appears to be similar pan India, with haplotype diversities peaking between March-May, while by June A2a (20A/B/C) emerged as the predominant one. Within haplotypes, different states appear to have different proportions. Temporal and geographic patterns in the sequences obtained reveal interesting clustering of mutations. Some mutations are present at particularly high frequencies in one state as compared to others. The negative estimate Tajimas D (D = -2.26817) is consistent with the rapid expansion of SARS-CoV-2 population in India. Detailed mutational analysis across India to understand the gradual emergence of mutants at different regions of the country and its possible implication will help in better disease management.

genomics↗

Phylogenomic analysis of SARS-CoV-2 genomes from western India reveals unique linked mutations

India has become the third worst-hit nation by the COVID-19 pandemic caused by the SARS-CoV-2 virus. Here, we investigated the molecular, phylogenomic, and evolutionary dynamics of SARS-CoV-2 in western India, the most affected region of the country. A total of 90 genomes were sequenced. Four nucleotide variants, namely C241T, C3037T, C14408T (Pro4715Leu), and A23403G (Asp614Gly), located at 5UTR, Orf1a, Orf1b, and Spike protein regions of the genome, respectively, were predominant and ubiquitous (90%). Phylogenetic analysis of the genomes revealed four distinct clusters, formed owing to different variants. The major cluster (cluster 4) is distinguished by mutations C313T, C5700A, G28881A are unique patterns and observed in 45% of samples. We thus report a newly emerging pattern of linked mutations. The predominance of these linked mutations suggests that they are likely a part of the viral fitness landscape. A novel and distinct pattern of mutations in the viral strains of each of the districts was observed. The Satara district viral strains showed mutations primarily at the 3' end of the genome, while Nashik district viral strains displayed mutations at the 5' end of the genome. Characterization of Pune strains showed that a novel variant has overtaken the other strains. Examination of the frequency of three mutations i.e., C313T, C5700A, G28881A in symptomatic versus asymptomatic patients indicated an increased occurrence in symptomatic cases, which is more prominent in females. The age-wise specific pattern of mutation is observed. Mutations C18877T, G20326A, G24794T, G25563T, G26152T, and C26735T are found in more than 30% study samples in the age group of 10-25. Intriguingly, these mutations are not detected in the higher age range 61-80. These findings portray the prevalence of unique linked mutations in SARS-CoV-2 in western India and their prevalence in symptomatic patients. ImportanceElucidation of the SARS-CoV-2 mutational landscape within a specific geographical location, and its relationship with age and symptoms, is essential to understand its local transmission dynamics and control. Here we present the first comprehensive study on genome and mutation pattern analysis of SARS-CoV-2 from the western part of India, the worst affected region by the pandemic. Our analysis revealed three unique linked mutations, which are prevalent in most of the sequences studied. These may serve as a molecular marker to track the spread of this viral variant to different places.

genomics↗

Rhizobium desertarenae sp. nov., isolated from the Saline Desert Soil from the Rann of Kachchh, India.

A novel bacterial strain designated ADMK78T was isolated from the saline desert soil. The cells were rod-shaped, Gram-negative, and non-motile. The strain ADMK78T grows best at 28{degrees}C and pH 7.0 and can tolerate up to 2% (w/v) NaCl. Based on 16S rRNA gene phylogeny, the strain ADMK78T belongs to the genus Rhizobium, with the highest similarity to Rhizobium wuzhouense W44T (98.7%) and Rhizobium ipomoeae shin9-1T (97.9%). Core-genes based phylogenetic analysis revealed that the strain ADMK78T forms a distinct branch in between Rhizobium ipomoeae shin9-1T and Rhizobium selenitireducens BAA-1503T. The average nucleotide identity of ADMK78T was less than 82%, to members of the family Rhizobiaceae. The genomic DNA G+C content of strain ADMK78T is 58.6 mol%. The major fatty acids of strain ADMK78T were C18:0 and C18:1 {omega}7c. The strain ADMK78T showed differences in physiological, phenotypic, and protein profiles estimated by MALDI-TOF MS to its closest relatives. Based on the phenotypic, chemotaxonomic properties, and phylogenetic analyses, the strain ADMK78T could be distinguished from the recognized species of the genus Rhizobium. It is suggested to represent a novel species of this genus, for which the name Rhizobium desertarenae sp. nov. is proposed. The type strain is ADMK78T (=MCC 3400T; KACC 21383T; JCM 33657T).

microbiology↗

Homogenization of Rhizosphere Bacterial Communities by Pea (Pisum sativum L.) Cultivated under Different Conservation Agricultural Practices in the Eastern Himalayas

Conservation agriculture offers a suitable system to harmonize agriculture with the environment, especially in fragile ecosystems of North-East India. Soil microbes play pivotal roles in ecosystem functioning and act as indispensable indicators of overall fitness of crop plant and soil health. Here we demonstrated that altercations in residue management and tillage practices lead to the development of differential bacterial communities forcing the pea plants to recruit special groups of bacteria leading to highly homogenous rhizosphere communities. Pea rhizosphere and bulk soil samples were collected, and bacterial community structure was estimated by 16S rRNA gene amplicon sequencing and predictive functional analysis was performed using Tax4Fun. The effect on pea plants was evident in the bacterial communities as the overall diversity of rhizosphere samples was significantly higher to that of bulk soil samples. Bacillus, Staphylococcus, Planomicrobium, Enterobacter, Arthrobacter, Nitrobacter, Geobacter, and Sphingomonas were noticed as the most abundant genera in the rhizosphere and bulk soil samples. The abundance of Firmicutes and Proteobacteria altered significantly in the rhizosphere and bulk samples, which was further validated by qPCR. Selection of specific taxa by pea plant was indicated by the higher values of mean proportion of Rhizobium, Pseudomonas, Pantoea, Nitrobacter, Enterobacter and Sphingomonas in rhizosphere samples, and Massilia, Paenibacillus and Planomicrobium in bulk soil samples. Tillage and residue management treatments did not significantly alter the bacterial diversity, while their influence was observed on the abundance of few genera. Recorded results revealed that pea plant selects specific taxa into its rhizosphere plausibly to meet its requirements for nutrient uptake and stress amelioration under the different tillage and residue management practices.

microbiology↗

Functional and Comparative Genomics of Niche-Specific Adapted Actinomycetes Kocuria rhizophila Strain D2 Isolated from Healthy Human Gut

Incidences of infection and occurrence of Kocuria rhizophila in human gut are prominent but certainly no reports on the species ability to withstand human gastrointestinal dynamics. Kocuria rhizophila strain D2 isolated from healthy human gut was comprehensively characterized. The functional analysis revealed the ability to produce various gastric enzymes and sensitive to major clinical antibiotics. It also exhibited tolerance to acidic pH and bile salts. Strain D2 displayed bile-salt hydrolytic (BSH) activity, strong cell surface traits such as hydrophobicity, auto-aggregation capacity and adherence to human HT-29 cell line. Prominently, it showed no hemolytic activity and was susceptible to the human serum. Exploration of the genome led to the discovery of the genes for the above said properties and has ability to produce various essential amino acids and vitamins. Further, comparative genomics have identified core, accessory and unique genetic features. The core genome has given insights into the phylogeny while the accessory and unique genes has led to the identification of niche specific genes. Bacteriophage, virulence factors and biofilm formation genes were absent with this species. Housing CRISPR and antibiotic resistance gene was strain specific. The integrated approach of functional, genomic and comparative analysis denotes the niche specific adaption to gut dynamics of strain D2. Moreover the study has comprehensively characterized genome sequence of each strain to know the genetic difference and intern recognize the effects of on phenotype and functionality complexity. The evolutionary relationship among strains along and adaptation strategies has been included in this study.\n\nSignificanceReports of Kocuria rhizophila isolation from various sources have been reported but the few disease outbreaks in humans and fishes have been prominent, but no supportive evidence about the survival ability of Kocuria spp. within human GIT. Here, we report the gut adaption potential of K. rhizophila strain D2 by functional and genomic analysis. Further; comparative genomics reveals this adaption to be strain specific (Gluten degradation). Genetic difference, evolutionary relationship and adaptation strategies have been including in this study.

genomics↗

Comparative Genome Analysis Reveals Important Genetic Factors Associated with Probiotic Property in Enterococcus faecium strains

Enterococcus faecium though commensals in human gut, few strains provide beneficial effect to humans as probiotics, few are responsible for nosocomial infection and few as non-pathogens. Comparative genomics of E. faecium will help to reveal the genomic differences responsible for the said properties. In this study, we compared E. faecium strain 17OM39 with a marketed probiotic, non-pathogenic non-probiotic (NPNP) and pathogenic strains. The core genome analysis revealed, 17OM39 was closely related with marketed probiotic strain T110. Strain 17OM39 was found to be devoid of known vancomycin, tetracycline resistance genes and functional virulence genes. Moreover, 17OM39 is \"less open\" due to absence of frequently found transposable elements. Genes imparting beneficial functional properties were observed to be present in marketed probiotic T110 and 17OM39 strains. Additional, genes associated with colonization within gastrointestinal tract were detected across all the strains. Beyond shared genetic features; this study particularly identified genes that are responsible to impart probiotic, non-pathogenic and pathogenic features to the strains of E. faecium. The study also provides insights into the acquired and intrinsic drug resistance genes, which will be helpful for better understanding of the physiology of antibiotic resistance in E. faecium strains. In addition, we could identify genes contributing to the intrinsic ability of 17OM39 E. faecium isolate to be a potential probiotic.\n\nThe study has comprehensively characterized genome sequence of each strain to find the genetic variation and understand effects of these on functionality, phenotypic complexity. Further the evolutionary relationship of species along with adaptation strategies have been including in this study.

bioinformatics↗

Comparison of Small Gut and Whole Gut Microbiota of First-Degree Relatives with Adult Patients with Celiac Disease and Controls

Recent studies on celiac disease (CeD) have shown the role of gut microbiota alterations in CeD pathogenesis. Whether this alteration in the microbial community is the cause or effect of the disease is not well understood, especially in adult onset of disease. The first-degree relatives (FDRs) of CeD patients may provide an opportunity to study gut microbiome in pre-disease state as FDRs are genetically susceptible to CeD. By using 16S rRNA gene sequencing, we observed between the disease condition (CeD), pre-disease (FDR) and control subjects. However, differences were observed at the level of amplicon sequence variant (ASV), suggesting alterations in specific taxa between pre-diseases and diseased condition. Duodenal biopsies showed higher differences in ASVs compared to faecal samples indicating larger disruption of microbiota at disease site. Increased abundance of specific Helicobacter ASVs were observed in duodenum of CeD when compared to FDR (p < 0.01). In case of fecal samples CeD microbiome and Actinomyces. In addition, predicted functional metagenome showed reduced ability of gluten that ecosystem level diversity measures (except in the duodenum) were not significantly different is characterized by reduced abundance of beneficial taxa such as Akkermansia, Ruminococcus degradation by CeD faecal microbiota in comparison to FDRs and controls.

microbiology↗