Biology subjects

Breurec, S.

Publications and source records attributed to Breurec, S..

4 recordsLinked to original sources

bioRxiv2026

From sewage to shoreline: Tracing antibiotic resistance gene trends through tropical island wastewater treatment pathways

Wastewater is a key reservoir and transmission route for antibiotic resistance genes (ARGs), enabling their spread from influent to effluent and into receiving environments. However, how combined selective pressures (antibiotics, biocides, heavy metals, pharmaceuticals) influence resistant bacteria and ARG persistence over space and time remains poorly understood. Likewise, the role of the wastewater microbiome in ARG dynamics is still unclear, as few studies integrate microbiome shifts with chemical and environmental drivers. Here, we investigated how microbiome dynamics, chemical exposures, and environmental conditions shape clinically relevant ARG dynamics from sewage to receiving environments in Guadeloupe, French Caribbean. We analysed data collected from three wastewater continuums, (hospital-based, domestic, touristic) over four campaigns (September 2021-February 2023). We characterised ARG and microbiome composition spatiotemporal patterns and used a mixed-effect model to investigate ARG associations with potential drivers, including exposome factors, microbiome dissimilarity and environmental factors. Several ARGs were negatively associated with microbiome dissimilarity (Bray-Curtis distances) (aac(6)-Ib, aph(3)-III, blaSHV, blaTEM, intI1, qnrS, sul1 and tetM). Negative associations were also observed between upstream-downstream differences in anti-inflammatory drug concentrations and the abundance of aac(6)-Ib, aph(3)-III, blaCTX-M, ermB, intI1, and tetM. In contrast, ARG relative abundance was positively associated with upstream-downstream differences in antibiotic concentrations, suggesting selection along the continuum. These findings indicate that ARG dissemination along wastewater-to-coastal pathways is shaped by opposing processes, with microbiome turnover potentially limiting ARG persistence while chemical gradients promote specific gene enrichment. The outcome is ARG-specific, with implications for antimicrobial resistance risks associated with recreational waters, seafood consumption, and coastal ecosystem interactions.

microbiology↗

bioRxiv2025

Impacts of wastewater treatment and the exposome on antibiotic resistance gene dynamics: Insights from Guadeloupe, a French Caribbean Island

Wastewater treatment plants (WWTPs) are global hotspots for the dissemination of antibiotic resistance genes (ARGs), primarily driven by different anthropogenic activities. Chemical compounds commonly found in wastewater, including antibiotics, biocides, non-steroidal anti-inflammatory drugs (NSAIDs), and heavy metals, along with environmental factors such as temperature and precipitation, might enhance the selection of antibiotic-resistant bacteria (ARB) even at low concentrations, inadvertently promoting the proliferation of ARGs. Since WWTPs can vary in their removal efficiency and influent compositions, it is important to assess their impact in influencing the relative abundance of ARGs and pollutant concentrations in discharged effluent. We analyzed data collected in Guadeloupe, French Caribbean, using random forest and lasso to investigate changes in the resistome and exposome within untreated wastewater influents and treated effluents from three WWTPs. These WWTPs represented three distinct wastewater continuums--hospital-based, urban non-touristic, and urban touristic--each with unique influent compositions. The study, which spanned four sampling campaigns from September 2021 to January 2023, revealed that the reduction in ARG abundance by the WWTPs was lower than expected. Of the 16 clinically relevant genes and mobile genetic elements examined, the relative abundance of aph(3)-III, blaOXA, blaSHV, blaTEM, ermB, intI1, qnrS, and tetM was reduced by 59.8% to 89.9% across the three WWTPs. An increasing trend in the relative abundance of the mcr-1 gene was observed, showing a 9.52-fold increase in the treated effluent in the hospital continuum. Of the nine antibiotics tested, trimethoprim levels dropped by 70.8% in the touristic continuum and 78.8% in the non-touristic, while ciprofloxacin saw a significant 64.4% reduction only in the touristic continuum, while no other antibiotics or biocides among the eight tested were effectively removed. Regarding heavy metals, significant reductions were observed only in the non-touristic continuum, with cadmium (Cd), copper (Cu), and mercury (Hg) concentrations reduced by 32.5%, 21.1%, and 36.2%, respectively. Our findings provide insights into the associations between environmental factors and the relative abundance of ARGs in Guadeloupe. Generally, depending on the continuum, biocides, the antibiotic erythromycin, certain heavy metals (As, Cd, Cu, Cr, and Hg) and water temperature were associated with the relative abundance of clinically relevant ARGs. This study was not able to assess the impact of climate. Future research should include longitudinal studies with more frequent sampling to better investigate the evolution of antibiotic resistance in bacterial species and its associated drivers, including pollutants and climate-related factors.

microbiology↗

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↗

bioRxiv2019

Clonal transmission and new mechanism of resistance to trimethoprim-sulfamethoxazole in Stenotrophomonas maltophilia strains isolated in a neonatology unit at Antananarivo, Madagascar, deciphered by whole genome sequence analysis

Stenotrophomonas maltophilia has been recognized as an emerging multidrug resistant organism in hospital settings due to its resistance to a broad range of antimicrobial agents. These include {beta}-lactams and aminoglycosides, afforded by the existence of intrinsic and acquired resistance mechanisms. Trimethoprim/sulfamethoxazole (SXT) is recommended as one of the best treatment choices against S. maltophilia infections; however increasing resistance to SXT has complicated the treatment. From July 2014 to March 2015, individuals and surfaces from a neonatology ward in Antananarivo, Madagascar, were longitudinally followed to assess the transmission of bacteria resistant to antibiotics between neonates, individuals (parents and nurses) and ward environments. Four S. maltophilia strains were successively isolated from a water-tap (N=1), from feces obtained from a newborn (N=1), and nursing staff (N=2). Antimicrobial susceptibility testing and whole genome sequencing were performed on each isolate. Based on coregenome alignment, all strains were identical and belonged to the new sequence type ST-288. They were resistant to trimethoprim-sulfamethoxazole, carbapenems and intermediate to levofloxacin. Each isolate carried the aadB, strA, strB and sul1 genes located in a class I integron but variants of the dfrA gene were absent. We assessed by PROVEAN analysis the single nucleotide mutations found in folA, folC and folM genes and only the mutation in folA (A114T:GCC[->]ACC) has an effect on the activity of trimethoprim. Our findings demonstrated the prolonged presence of SXT-resistant S. maltophilia in a clinical setting with consecutive transfers from the environment to a newborn and staff based on the isolation dates. We also hypothesized that single nucleotide mutations in folA could be responsible for trimethoprim resistance.

microbiology↗