Biology subjects

Guernier-Cambert, V.

Publications and source records attributed to Guernier-Cambert, V..

3 recordsLinked to original sources

bioRxiv2026

Pathogenic Leptospira in dogs and rodents in Tha Wang Pha, Thailand - Prevalence, diversity and linked environments

Human leptospirosis is a disease of public health importance in Thailand, but the animal species involved in the transmission cycle have not been fully uncovered. This study investigated Leptospira infection in dogs and terrestrial micromammals in rural Nan Province, Thailand, and the pathogen diversity. Sera from 95 seemingly healthy dogs and kidney samples from 399 micromammals were analyzed using real-time PCR for Leptospira detection, followed by conventional PCR and sequencing of infecting Leptospira. We investigated environmental factors associated with Leptospira infection in micromammals, using data collected during trapping. Real-time PCR revealed ongoing infection in 8.4% (8/95) of dogs and 10.0% (40/399) of terrestrial micromammals, with 12 infected species including Bandicota indica, Berylmys berdmorei, Berylmys bowersi, Mus cervicolor, Mus cookii, and Hylomys suillus. In this qPCR-positive micromammals, three pathogenic Leptospira species were identified: L. interrogans, L. weilii, and L. borgpetersenii. This represents the first confirmed detection of L. weilii in rodents in Thailand. Infected micromammals were found in agricultural and forest habitats but not in human settlements. Our study demonstrates potential complex leptospirosis epidemiology in rural Thailand, with multiple species serving as pathogenic Leptospira reservoirs across diverse habitats, and some shared pathogen diversity with human leptospirosis cases in Thailand. Free-roaming dogs may serve as bridge hosts, transmitting zoonotic Leptospira from micromammals to humans by visiting both animal habitats and human settlements. These findings emphasize the need for integrated One Health surveillance approaches to control leptospirosis in rural communities.

molecular biology↗

bioRxiv2024

Serological screening in animals combined with environmental surveys provides definite proof of the local establishment of Burkholderia pseudomallei in Guadeloupe

BackgroundMelioidosis is an emerging infectious disease caused by the soil-dwelling bacterium Burkholderia pseudomallei that affects both humans and animals. It is endemic in South and Southeast Asia, and northern Australia, causing an estimated 165,000 human cases annually worldwide. Human cases have been reported in the French West Indies (Martinique and Guadeloupe) since the 1990s. Conversely, no human cases have been reported in French Guiana, a French territory in South America. Our study aimed to investigate whether B. pseudomallei is locally established in Guadeloupe and French Guiana. We assessed animal exposure by serology and examined the presence of B. pseudomallei in the environment of seropositive animals. Methodology/Principal findingsBlood samples were collected from domestic animals in two goat farms in Les Saintes, Guadeloupe (n=31), and in 56 farms in French Guiana (n=670) and tested by ELISA. Serological follow up was performed on selected farms. Soil, water and goat rectal swabs were collected and analysed by culture and PCR. In French Guiana, the highest prevalence rates were observed in equids (24%) and cattle (16%), while in Les Saintes, a prevalence of 39% was observed in goats. The longitudinal study in Les Saintes revealed consistent high seropositivity in goats. A B. pseudomallei strain was isolated from the soil from one of the farms and detected in goat rectal swabs from the other farm. Conclusions/SignificanceOur environmental investigation prompted by the serologic data confirms the presence of B. pseudomallei in Les Saintes, consistent with documented human cases of melioidosis on this island. In French Guiana, our serologic results call for environmental surveys and a re-evaluation of human infections with melioidosis-like symptoms. The approach developed in this study may help to identify high-risk areas that warrant further investigation. Author summaryBurkholderia pseudomallei, an environmental bacterium, is the causative agent of melioidosis in humans and animals. If the disease has been historically reported to be endemic in South Asia and northern Australia, recent studies reveal its presence outside of these territories, both in the environment and among patients who have not travelled to endemic areas. Furthermore, the projected increase in extreme climatic events in the near future could increase the prevalence of the disease as well as cause its emergence in new territories. For these reasons, it is important to identify new areas at risk. Our study aimed to investigate the presence of the pathogen in French West Indies. We combined surveys in domestic animals (cattle, goats, horses, sheep, and pigs) and in the environment. The identification of seropositive animals without clinical signs, together with the isolation of B. pseudomallei in the environment of a goat farm in Guadeloupe, underscores the importance of including melioidosis in animal surveillance programs. The use of serologic methods can help identify animal exposure to the pathogen, thereby helping to identify areas where the pathogen may be present in the environment.

microbiology↗

bioRxiv2020

A preliminary investigation of major bacterial antibiotic resistance genes present in Australian fecal samples using shotgun metagenomics and targeted sequencing.

The gut microbiota is an immense reservoir of antimicrobial resistance genes (ARGs); however, in Australia the profile of the gut resistome, or ensemble of ARGs, has not been investigated. This study provides a first preliminary mapping of the major bacterial ARGs present in human, domestic dog and wild duck fecal samples collected from south-eastern Victoria, Australia; and evaluates the use of shotgun metagenomics sequencing (SMS) and targeted amplification of ARGs. We analysed SMS data using an in-house method and web-based bioinformatics tools: ResFinder and KmerResistance. We examined targeted sequences using One Codex or the PanBacterialAnalysis Torrent Suite plugin. All methods detected ARGs in all samples, with resistance to up to 13 classes of antibiotics detected overall. ARGs were more abundant in the human and dog samples than the duck samples. They mostly conferred resistance to three classes of antibiotics that are the most frequently prescribed in Australia: tetracycline, {beta}-lactams and MLSB (macrolide, lincosamide, streptogramin B). Targeted sequencing significantly improved sensitivity for detection of ARGs included in the panel; however, SMS provided quantitative information and allowed tentative identification of the host bacteria. For SMS, web-based and in-house methods gave comparable results, with discrepancies mostly due to different reference databases. The in-house method allowed manually checking results and potential errors, while web-based methods were user-friendlier and less time-consuming. More samples need to be investigated to fully describe the resistome in humans and animals in Australia.

genomics↗