Environmental surveillance of Pseudomonas aeruginosa in recreational waters in tourist facilities of the Balearic Islands, Spain (2016-2019)

Abstract

Background: Pseudomonas aeruginosa is a major opportunistic human pathogen commonly connected with recreational water activities. Spain is a tourist destination where most of the establishments have swimming pool. Nevertheless, the prevalence of P. aeruginosa in public swimming pools in our country is unknown. This works aimed to survey the P. aeruginosa presence in tourist Spanish recreational waters. Method: Tourist recreational water in hotels in the Balearic Islands were visited for four years (2016-2019). The levels of selected parameters were determined, and their correlation with P. aeruginosa contamination investigated. Results: We evaluated 11,014 samples from 254 facilities. Unacceptable levels of at least one legislated parameter were detected in 30.7% of cases, implicating closure in 15.9%, being P. aeruginosa the leading cause of closure. The prevalence of the pathogen was 14.2%, with lower presence in outer swimming pools. Disinfectant levels influence P. aeruginosa contamination, and bromine-maintained pools were more often contaminated than those treated with chlorine. Prevalence remained constant over the years, although it increased in 2019. Conclusions: P. aeruginosa prevalence in our recreational waters is similar to other countries, and the contamination rates depend on the installations and type and disinfectant levels. Corrective measures are still needed to improve pathogen control.