Healthcare and Hospital Management

Mycobacterium avium subsp. paratuberculosis (MAP) has been implicated in the development of infl ammatory bowel disease (IBD) and colorectal cancer. Portugal has a high prevalence of IBD and Porto is one of the Portuguese districts with higher IBD prevalence.

Our goal was to assess MAP contamination in drinking and domestic untreated water sources in Porto geographical area, since water may be an important contaminating source of MAP for humans. One liter of public drinking water and/or a domestic untreated water source were collected at diff erent locations in Porto area in early Autumn. Biofi lms were also collected by swabbing tap inner surfaces with a sterile cotton swab. A second collection of domestic untreated water was performed aft er winter rains, in early February. Water samples were fi ltered and DNA was extracted from both water fi lters and biofi lmsuspensions using specifi c commercial kits. MAP  contamination was evaluated through a IS900-based nested PCR assay. Drinking water samples showed higher MAP contamination than domestic water collected in Autumn. In February, MAP detection signifi cantly increased in domestic water. MAP DNA was detected at a higher frequency in tap biofi lms than in the corresponding water collected. Drinking and domestic water may be important sources of MAP contamination in Porto area. The increased MAP detection observed aft er winter rains in domestic water may refl ect soil leaching. Since MAP can resist to water treatment procedures and persist in biofi lms, increased microbial surveillance and development of new water treatment methods are most needed to avoid human exposure to this resilient pathobiont.