Biology subjects

Kushwaha, S. K.

Publications and source records attributed to Kushwaha, S. K..

4 recordsLinked to original sources

bioRxiv2024

KlebPhaCol: A community-driven resource for Klebsiella research identified a novel gut phage order associated with the human gut

The growing threat of multidrug-resistant Klebsiella pneumoniae, coupled with its role in gut colonisation, has intensified the search for new treatments, including bacteriophage therapy. Despite increasing documentation of Klebsiella-targeting phages, clinical applications remain limited, with key phage-bacteria interactions still poorly understood. A major obstacle is fragmented access to well-characterised phage-bacteria pairings, restricting the collective advancement of therapeutic and mechanistic insights. To address this gap, we created the Klebsiella Phage Collection (KlebPhaCol), an open-source resource comprising 53 phages and 74 Klebsiella isolates, all fully characterised. These phages span five families - including a novel order, Felixvirales, associated with the human gut - and target 27 sequence types (including ST258, ST11, ST14) and 28 capsular-locus types (including KL1 and KL2), across six Klebsiella species. Freely accessible at www.klebphacol.org, KlebPhaCol invites the scientific community to both use and contribute to this resource, fostering collaborative research and a deeper understanding of Klebsiella-phage interactions beyond therapeutic use.

microbiology↗

bioRxiv2022

Defence systems provide synergistic anti-phage activity in E. coli

Bacterial defence against phage predation involves diverse defence systems acting both individually and concurrently, yet their interactions remain poorly understood. We investigated >100 defence systems in 42,925 bacterial genomes and identified numerous instances of their non-random co-occurrence and mutual exclusion. For several pairs of defence systems significantly co-occurring in Escherichia coli strains, we demonstrate synergistic anti-phage activity, including tmn synergising with defence systems containing sensory switch ATPase domains. Some of the defence system pairs that are mutually exclusive in E. coli significantly co-occur in other taxa, and one tested mutually exclusive pair showed synergy. These findings demonstrate compatibility and synergy between defence systems, allowing bacteria to adopt flexible strategies for phage defence, driven by specific environmental pressures. The evolution of bacterial immune repertoires seems to be shaped largely by selection for resistance to host-specific phages rather than by negative epistasis.

microbiology↗

bioRxiv2022

Comparative small RNA and degradome sequencing provide new insights into antagonistic interactions in the biocontrol fungus Clonostachys rosea

Necrotrophic mycoparasitism is an intricate process involving recognition, physical mycelial contact and killing of host fungi (mycohosts). During such interactions, mycoparasites undergo a complex developmental process involving massive regulatory changes of gene expression to produce a range of chemical compounds and proteins that contribute to the parasitism of the mycohosts. Small-RNAs (sRNAs) are vital components of post-transcriptional gene regulation, although their role in gene expression regulation during mycoparasitism remain understudied. Here, we investigated the role of sRNA-mediated gene regulation in mycoparasitism by performing sRNA and degradome tags sequencing of the mycoparasitic fungus Clonostachys rosea interacting with the plant pathogenic mycohosts Botrytis cinerea and Fusarium graminearum at two time points. The majority of differentially expressed sRNAs were down-regulated during the interactions with the mycohosts compared to a C. rosea self-interaction control, thus allowing de-suppression (up-regulation) of mycohost-responsive genes. Degradome analysis showed a positive correlation between high degradome counts and antisense sRNA mapping and led to the identification of 201 sRNA-mediated gene targets for 282 differentially expressed sRNAs. Analysis of sRNA gene targets revealed that the regulation of genes coding for membrane proteins was a common response against both mycohosts. While the regulation of genes involved in oxidative stress tolerance and cellular metabolic and biosynthetic processes was exclusive against F. graminearum highlighting common and mycohosts-specific gene regulation of C. rosea. By combining these results with transcriptome data collected in similar experimental conditions during a previous study, we expand the understanding of the role of sRNA in regulating interspecific fungal interactions and mycoparasitism. ImportanceSmall-RNAs (sRNAs) are emerging as key players in pathogenic and symbiotic fungus-plant interactions, however, their role in fungal-fungal interactions remains elusive. In this study, we employed the necrotrophic mycoparasite Clonostachys rosea and plant pathogenic mycohots Botrytis cinerea and Fusarium graminearum and investigated the sRNA-mediated gene regulation in mycoparasitic interactions. The combined approach of sRNA and degradome tag sequencing identified 201 sRNA-mediated putative gene targets for 282 differentially expressed sRNAs highlighting the role of sRNA-mediated regulation of mycoparasitism in C. rosea. We also identified 36 known and 13 novel miRNAs and their potential gene targets at endogenous level, and at a cross-species level in B. cinerea and F. graminearum indicating a role of cross-species RNAi in mycoparasitism, representing a novel mechanism in biocontrol interactions. Furthermore, we showed that C. rosea adapts its transcriptional response, and thereby its interaction mechanisms, based on the interaction stages and identity of the mycohost.

microbiology↗

bioRxiv2020

SARS-CoV-2 transcriptome analysis and molecular cataloguing of immunodominant epitopes for multi-epitope based vaccine design

SARS-CoV-2 is a single-stranded RNA virus that has caused more than 0.29 million deaths worldwide as of May 2020, and influence of COVID-19 pandemic is increasing continuously in the absence of approved vaccine and drug. Moreover, very limited information is available about SARS-CoV-2 expressed regions and immune responses. In this paper an effort has been made, to facilitate vaccine development by proposing multiple epitopes as potential vaccine candidates by utilising SARS-CoV-2 transcriptome data. Here, publicly available RNA-seq data of SARS-CoV-2 infection in NHBE and A549 human cell lines were used to construct SARS-CoV-2 transcriptome to understand disease pathogenesis and immune responses. In the first step, epitope prediction, MHC class I and II gene identification for epitopes, population coverage, antigenicity, immunogenicity, conservation and crossreactivity analysis with host antigens were performed by using SARS-CoV-2 transcriptome, and in the second step, structural compatibility of identified T-and B-cell epitopes were evaluated with MHC molecules and B-cell receptors through molecular docking studies. Quantification of MHC gene expression was also performed that indicated high variation in allele types and expression level of MHC genes with respect to cell lines. In A549 cell line, HLA-A*30:01:01:01 and HLA-B*44:03:01:01 were highly expressed, whereas 92 variants of HLA-A*24 genes such as HLA-A*24:02:01:01, HLA-A*24:286, HLA-A*24:479Q, HLA-A*24:02:134 and HLA-A*24:02:116 were highly expressed in NHBE cell lines. Prevalence of HLA-A*24 alleles was suggested as risk factors for H1N1 infection, and associated with type-1 diabetes. HLA-C*03:03, linked with male infertility factors was also highly expressed in SARS-CoV-2 infected NHBE cell lines. Finally, three potential T-cell and five B-cell epitopes were selected for molecular docking studies with twenty-two MHC molecules and two B-cell receptors respectively. The results of in silico analysis indicated that proposed epitopes have high potential to recognize immune response of SARS-CoV-2 infection. This study will facilitate in vitro and in vivo vaccine related research studies.

bioinformatics↗