Biology subjects

Jagannadham, J.

Publications and source records attributed to Jagannadham, J..

3 recordsLinked to original sources

bioRxiv2025

Genomic insights into six clinical isolates of Stenotrophomonas maltophilia from Northern India

Stenotrophomonas maltophilia is a gram-negative opportunistic pathogen that causes respiratory, urinary and bloodstream infections. Due to rising prevalence of difficult to treat S. maltophilia infections, it is considered as one of the important pathogens in many regions, including India. Despite its importance in public health, very few studies provide detailed characterization of the genomes of clinical isolates of S. maltophilia. In this study, we sequence six isolates of S. maltophilia from a tertiary healthcare centre in the Northern India. Along with the culture sensitivity, we report the genomic underpinnings of resistance and virulence in these isolates. In three out of six isolates, we identify a rare beta-lactamase gene kbl-1 that can confer resistance to variety of beta-lactam antibiotics. Though truncated in two isolates, an intact copy of kbl-1 is present in the third isolate. This intact copy of kbl-1 is flanked by insertion elements that are commonly found in several pathogenic species indicating high potential for horizontal gene transfer. To the best of our knowledge, this is a first report of kbl-1 in S. maltophilia from India. ImportanceAntimicrobial resistance (AMR) is one of the biggest global public health challenges. Tackling AMR gets complicated as diverse pathogenic species are involved and resistance is manifested against several different kinds of antibiotics. Genomic surveillance of the resistant pathogens is a key to fight this global threat and needs to extend to important emerging pathogens as well. Here we report genomic sequences and associated characteristics of six Stenotrophomonas maltophilia isolates from Northern India. Along with several resistance and virulence genes we also discover a rare beta-lactamase, blaKBL-1, gene with a high potential of transfer to other species. blaKBL-1 beta-lactamase confers resistance to several beta-lactam antibiotics like ampicillin, amoxicillin, penicillin G, piperacillin, ceftazidime and cefozopran. This is the first report of the presences of this beta-lactamase from India.

microbiology↗

bioRxiv2023

Genomic sequencing should extend to diverse priority pathogens for effective study and surveillance of antimicrobial resistance: a systematic review of whole-genome sequencing studies from India

BackgroundAntimicrobial resistance (AMR) is a public health emergency in many low and middle-income countries, including India. To effectively tackle AMR, we need rapid diagnostics, effective surveillance and new antimicrobial drugs. Whole-genome sequencing of pathogens is the first definite step towards achieving these goals. MethodsIn this work, we review all the studies published till date that report whole-genome sequences of select priority AMR pathogens from India. We searched PubMed and Web of Science databases for the studies that involved whole-genome sequencing of AMR priority pathogens from India. For the top two highly sequenced pathogens, S. typhi and K. pneumoniae, we performed phylogenetic analyses to understand the geo-climatic distribution of genetically diverse strains. ResultsOur search reveals 94 studies that report 2547 unique whole-genome sequences. We find that most sequences are limited to select priority pathogens isolated from a couple of geo-climatic zones of India. Our phylogenetic analyses show that available data does not indicate systematic differences between the genomes of isolates from different geo-climatic zones. Our search also reveals complete absence of travel-related studies tracking possible movement of AMR pathogens within country. Lastly, we find very few studies that sequence AMR pathogens isolated from food, soil or other environments. ConclusionTogether, these observations suggest that lndia should prioritize sequencing of diverse AMR pathogens from clinics as well as from environments and travellers rather than extending the geo-climatic range of already-sequenced pathogens. Our recommendations can be potentially valuable for other low and middle-income countries with limited resources, high prevalence of AMR and diverse geo-climatic conditions.

microbiology↗

bioRxiv2017

Identification and analysis of mobile genetic elements in Gibbon genome

Recent sequencing of genome of northern white-cheeked gibbon (Nomascus leucogenys) has provided important insight into fast evolution of gibbons and signatures relevant to gibbon biology. It was revealed that mobile genetic elements (MGE) seems to play major role in gibbon evolution. Here we report that most of the gibbon genome is occupied by the MGEs such as ALUs, MIRs, LINE1, LINE 2, LINE 3, ERVL, ERV-class1, ERV-class II and other DNA elements which include hAT Charlie and TcMar tigger. We provide detailed description and genome wide distribution of all the MGEs present in gibbon genome. Previously, it was reported that gibbon-specific retrotransposon (LAVA) tend to insert into chromosome segregation genes and alter transcription by providing a premature termination site, suggesting a possible molecular mechanism for the genome plasticity of the gibbon lineage. We show that insertion sites of LAVA elements present atypical signals/patterns which are different from typical signals present at insertion sites of Alu elements. This suggests possibility of distinct insertion mechanism used by LAVA elements for their insertions. We also find similarity in signals of LAVA elements insertion sites with atypical signals present at Alus /L1s insertion sites disrupting the genes leading to diseases such as cancer and Duchenne muscular dystrophy. This suggest role of LAVA in premature transcription termination.

bioinformatics↗