A cross-sectional study on the prevalence of illness in coastal bathers compared to non-bathers in England and Wales: Findings from the Beach User Health Survey

Longitudinal carriage of antimicrobial resistant Enterobacterales in healthy individuals in Ireland - Assessing the impact of recreational water use on duration of carriage

The increasing prevalence of extended-spectrum beta-lactamase (ESBL) producing Enterobacterales (ESBL-PE) and carbapenemase-producing Enterobacterales (CPE) is a major public health concern worldwide. Despite the associated risk of infection from gut colonisation with a resistant Enterobacterales, the incidence and duration of carriage in healthy individuals is poorly studied. This "persistence study" is the first in Ireland to assess the longitudinal carriage of ESBL-PE and CPE in healthy individuals. A cohort of 45 participants, 22 of whom were colonised with ESBL-PE, was recruited from a recently completed point prevalence study that investigated colonisation in recreational water users (WU) versus controls. Six bi-monthly faecal samples per participant were analysed for CPE and ESBL-PE over one year and the relationship between persistent colonisation and exposure to natural waters was investigated. For 11 of 45 participants (24.4 %) ESBL-E. coli (ESBL-EC) was detected in at least one sample. Genomic analysis revealed that six participants harboured the same ESBL-EC strains as identified in the preceding study. ESBL-EC persisted in the gut for a median duration of 10.3 months (range 4-23 months), consistent with previous research. Five participants (11.1 %) carried ESBL-EC for the entire study year. The carbapenemase gene blaIMI-2 was detected once. Colonisation was higher in water users during the non-bathing season (n = 10, November 2021-April 2022), than during the bathing season (n = 5, May 2022-September 2022) [relative risk 1.99 (95 % CI 0.34-11.71)]. However, overall WU were less likely to be colonised with ESBL-EC than controls (19 % vs 25 % respectively, RR 0.76, CI 0.24-2.34). Further research is warranted to better understand the factors influencing the persistence of gut colonisation with ESBL-EC and CPE and to what extent bathing water quality impacts colonisation for those regularly exposed.

Natural recreational waters and the risk that exposure to antibiotic resistant bacteria poses to human health

Antimicrobial resistance (AMR) is widely recognised as a considerable threat to human health, wellbeing and prosperity. Many clinically important antibiotic resistance genes are understood to have originated in the natural environment. However, the complex interactions between humans, animals and the environment makes the health implications of environmental AMR difficult to quantify. This narrative review focuses on the current state of knowledge regarding antibiotic resistant bacteria (ARB) in natural bathing waters and implications for human health. It considers the latest research focusing on the transmission of ARB from bathing waters to humans. The limitations of existing evidence are discussed, as well as research priorities. The authors are of the opinion that future studies should include faecally contaminated bathing waters and people exposed to these environments to accurately parameterise environment-to-human transmission.

Antibiotic Resistance Genes and Potentially Pathogenic Bacteria in the Central Adriatic Sea: Are They Connected to Urban Wastewater Inputs?

Despite last decades’ interventions within local and communitarian programs, the Mediterranean Sea still receives poorly treated urban wastewater (sewage). Wastewater treatment plants (WWTPs) performing primary sewage treatments have poor efficiency in removing microbial pollutants, including fecal indicator bacteria, pathogens, and mobile genetic elements conferring resistance to antimicrobials. Using a combination of molecular tools, we investigated four urban WWTPs (i.e., two performing only mechanical treatments and two performing a subsequent conventional secondary treatment by activated sludge) as continuous sources of microbial pollution for marine coastal waters. Sewage that underwent only primary treatments was characterized by a higher content of traditional and alternative fecal indicator bacteria, as well as potentially pathogenic bacteria (especially Acinetobacter, Coxiella, Prevotella, Streptococcus, Pseudomonas, Vibrio, Empedobacter, Paracoccus, and Leptotrichia), than those subjected to secondary treatment. However, seawater samples collected next to the discharging points of all the WWTPs investigated here revealed a marked fecal signature, despite significantly lower values in the presence of secondary treatment of the sewage. WWTPs in this study represented continuous sources of antibiotic resistance genes (ARGs) ermB, qnrS, sul2, tetA, and blaTEM (the latter only for three WWTPs out of four). Still, no clear effects of the two depuration strategies investigated here were detected. Some marine samples were identified as positive to the colistin-resistance gene mcr-1, an ARG that threatens colistin antibiotics’ clinical utility in treating infections with multidrug-resistant bacteria. This study provides evidence that the use of sole primary treatments in urban wastewater management results in pronounced inputs of microbial pollution into marine coastal waters. At the same time, the use of conventional treatments does not fully eliminate ARGs in treated wastewater. The complementary use of molecular techniques could successfully improve the evaluation of the depuration efficiency and help develop novel solutions for the treatment of urban wastewater.

Ocean Literacy and Surfing: Understanding How Interactions in Coastal Ecosystems Inform Blue Space User's Awareness of the Ocean

Intergovernmental policy is targeting public ocean literacy to help achieve the societal changes needed to reach a sustainable ocean agenda within a 10-year timeframe. To create a culture of care for the ocean, which is under threat from Anthropocentric pressures, informed ocean citizens are central to upholding meaningful actions and best practices. This research focuses on recreational ocean users, specifically surfers and how their blue space activities may inform understanding of ocean processes and human-ocean interconnections. The Ocean Literacy Principles were used to assess ocean awareness through surfing interactions. An online survey questionnaire was completed by 249 participants and reduced to a smaller sample focus group. Qualitative and quantitative data were triangulated to develop further understanding of surfer experiences, using the social-ecological systems framework to model surfing outcomes. The results found that surfers indeed receive ocean literacy benefits, specifically three out of the seven Ocean Literacy Principles and that ocean literacy is a direct benefit many surfers in the sample group receive. By identifying synergies between the Ocean Literacy Principles, variables within coastal ecosystems and user (surfer) interactions, this research offers novel insight into opportunities for integrating ocean sustainability strategies through blue space activity mechanisms and coastal community engagement.