Wastewater-based AMR surveillance associated with tourism on a Caribbean island (Guadeloupe)

Antimicrobial resistance (AMR) is a major public health concern worldwide. International travel is a risk factor for acquiring antibiotic-resistant bacteria (ARB) and antibiotic-resistance genes (ARGs). Therefore, understanding the transmission of ARB and ARGs is instrumental in tackling AMR. This longitudinal study aimed to assess the benefit of wastewater monitoring in Guadeloupe to evaluate the role of tourism in the spread of AMR.

A wastewater-based surveillance (WBS) study was conducted to monitor AMR in Guadeloupe in 2022 during dry and wet seasons. We characterized the resistome, microbiome and exposome of water samples collected in wastewater treatment facilities of two cities with different levels of tourism activities, in the content of aircraft toilets, and the pumping station receiving effluents from hotels.

The results show that the WBS approach facilitates the differentiation of various untreated effluents concerning exposome, microbiome, and resistome, offering insights into AMR dissemination. Additionally, the findings reveal that microbiome and exposome are comparable across sites and seasons, while resistome characterisation at specific locations may be pertinent for health surveillance. The microbiome of aircraft was predominantly composed of anaerobic bacteria from human intestinal microbiota, whereas the other locations exhibited a blend of human and environmental bacteria. Notably, individuals arriving by air have not introduced clinically significant resistance genes. Exposome compounds have been shown to influence the resistome's variance.

Clear differences were seen between the aircraft and the local sampling sites, indicating that the contribution of tourism to the observed resistance in Guadeloupe is not significant.