Biology subjects

Kimber, M.

Publications and source records attributed to Kimber, M..

3 recordsLinked to original sources

bioRxiv2024

Exploring the uncharted: Novel potential filariasis vectors unveiled in Sri Lanka

Brugian filariasis (BF) has reemerged in Sri Lanka recently. Studies suggest the emergence of a variant brugian parasite. Knowledge on transmission dynamics is important in restraining the spread of infection. This study investigated the potential vector mosquitoes of this variant brugian parasite around six indexed human BF cases in five BF endemic districts in Sri Lanka. A total of 1711 mosquitoes from 20 species were analyzed. Potential infective mosquitoes were detected by the presence of L3 larval stage of brugian parasites within the head and thorax regions upon dissections and confirmed by amplification of the Brugia species-specific HhaI region. Twelve (12) mosquito species that could potentially serve as vectors for BF transmission in selected endemic areas in the country were identified due to the presence of L3 larvae in the head and thorax regions. This is the first report of Ma. indiana, Ar. subalbatus, Ae. albopictus, Cq. crassipes, Cx. tritaeniorhynchus, Cx. bitaeniorhynchus, Cx. quinquefasciatus, Cx. gelidus, Cx. lopoceraomyia and Cx. vishnui with the potential of serving as vectors for BF transmission in Sri Lanka and Cx. bitaeniorhynchus, Cx. gelidus, Cx. lopoceraomyia and Cx. vishnui in the world through a field study. Of these, Ma. indiana, Cx. tritaeniorhynchus, Cx. quinquefasciatus and Ar. subalbatus together with Ma. uniformis, Ma. annulifera had the highest prevalence and infection rate at certain study sites. The recovery of parasite-positive Ma. indiana, Cx. quinquefasciatus and Ar. subalbatus mosquitoes from window traps demonstrate the probable anthropophilic nature of these species, and their high prevalence in the respective areas deems further investigation on their vector potentiality essential. Author SummaryLymphatic filariasis (LF) is a debilitating disease affecting over 120 million people worldwide. Of the two types of LF, Brugian Filariasis (BF) has a wide range of definitive hosts, making it possible for the rapid spread of the disease. BF was considered eliminated from Sri Lanka in 1969 but is on the rise after four decades of quiescence. Effective vector control is an integral part of infection control. We carried out entomological investigations for potential vectors of re-emerged BF in five BF-endemic areas in Sri Lanka. Here we report Ma. indiana, Cx. tritaeniorhynchus, Cx. bitaeniorhynchus, Cx. quinquefasciatus, Cx. gelidus, Cx. lopoceraomyia, Cx. vishnui, Ar. subalbatus, Ae. albopictus and Cq. crassipes with the potential to serve as vectors for BF transmission in Sri Lanka due to the presence of L3 larvae in the head and thorax regions and Cx. bitaeniorhynchus, Cx. quinquefasciatus, Cx. gelidus, Cx. lopoceraomyia and Cx. vishnui in the world. The high prevalence and infection rate of Ma. indiana, Cx. quinquefasciatus and Ar. subalbatus mosquitoes and their anthropophagic nature in certain BF endemic areas are worrisome. This study emphasizes the importance of a comprehensive analysis of BF vectors for vector control strategies tailored to each region and season.

zoology↗

bioRxiv2018

Adult Canine Intestinal Derived Organoids: A Novel In Vitro System for Translational Research in Comparative Gastroenterology

BackgroundLarge animal models, such as the dog, are increasingly being used over rodent models for studying naturally occurring diseases including gastrointestinal (GI) disorders. Dogs share similar environmental, genomic, anatomical, and intestinal physiologic features with humans. To bridge the gap between currently used animal models (e.g. mouse) and humans, and expand the translational potential of the dog model, we developed a three dimensional (3D) canine GI organoid (enteroid and colonoid) system. Organoids have recently gained interest in translational research as this model system better recapitulates the physiological and molecular features of the tissue environment in comparison with two-dimensional cultures.\n\nResultsOrganoids were propagated from isolation of adult intestinal stem cells (ISC) from whole jejunal tissue as well as endoscopically obtained duodenal, ileal and colonic biopsy samples of healthy dogs and GI cases, including inflammatory bowel disease (IBD) and intestinal carcinomas. Intestinal organoids were comprehensively characterized using histology, immunohistochemistry, RNA in situ hybridization and transmission electron microscopy, and organoids mimicked the in vivo tissue environment. Physiological relevance of the enteroid system was defined using functional assays such as Optical Metabolic Imaging (OMI), the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) function assay, and Exosome-Like Vesicles (EV) uptake assay, as a basis for wider applications of this technology in basic, preclinical and translational GI research.\n\nConclusionsIn summary, our findings establish the canine GI organoid systems as a novel model to study naturally occurring intestinal diseases in dogs and humans. Furthermore, canine organoid systems will help to elucidate host-pathogen interactions contributing to GI disease pathogenesis.

cell biology↗

bioRxiv2018

Chemosensory structure and function in the filarial nematode, Brugia malayi.

Nematode chemosensory behaviors underlie fundamental processes and activities in development, reproduction, tropisms and taxes. For parasitic species, chemosensation is essential for host seeking and host and tissue invasion behaviors. Such fundamental biology presents an attractive target for developing behavior-blocking anthelminthic drugs, but the anatomy and functional relevance of parasitic nematode chemosensory machinery are poorly understood. The goals of this study were to better understand the chemosensory apparatus and behaviors of infectious stage Brugia malayi (Spirurida: Onchocercidae), a mosquito-borne nematode and etiological agent of Lymphatic Filariasis. Scanning electron microscopy revealed that amphids, the major chemosensory organs, are present on adult B. malayi and arranged in a conserved manner. Internal sensory neuroanatomy display structural differences between life stages, and a simpler chemosensory architecture as compared to free-living nematodes. Positive and negative chemotactic behaviors were identified for a repertoire of chemicals with known chemostimulatory activity for the mosquito host that may facilitate host-selectivity and invasion. This is the first description of chemosensory anatomy and chemotactic behaviors in B. malayi that reveal the involvement of chemosensation in parasite transmission and host invasion.\n\nO_LSTKey findingsC_LST* Amphidial arrangement in B. malayi is less complex than free-living nematodes.\n* Chemosensory neuroanatomy is stage-specific and simpler than free-living nematodes.\n* B. malayi responses to stimuli can be measured using a plate-based assay.\n* Chemostimulants associated with mosquito host-seeking induce negative and positive tropisms for L3 stage B. malayi.

microbiology↗