Abstract
Mycobacterium avium subsp. paratuberculosis (MAP) may play a role in the pathology of human inflammatory bowel disease (IBD). Previously, we found a high frequency (98% in patients with active disease) of MAP DNA detection in the blood of Portuguese Crohn's Disease patients, suggesting this cohort has high exposure to MAP organisms. Water is an important route for MAP dissemination, in this study we therefore aimed to assess MAP contamination within water sources in Porto area (the residential area of our IBD study cohort).Water and biofilms were collected in a wide variety of locations within the Porto area, including taps connected to domestic water sources and from municipal water distribution systems. Baseline samples were collected in early autumn plus further domestic water samples in early winter, to assess the effect of winter rainfall. DNA was extracted from all 131 samples and IS900-based nested PCR used to assess the frequency of MAP presence.Our results show high MAP positivity in municipal water sources (20.7% of water samples and 41.4% of biofilm samples) and even higher amongst domestic sources (30.8% of water samples and 50% of biofilm samples). MAP positivity in biofilms correlated with positivity in water samples from the same sources. A significantly higher frequency of MAP-positivity was observed during winter rains as compared with samples collected in autumn prior to the winter rainfall period (61.9% versus 30.8%). We conclude that domestic and municipal water sources of Porto region have a high burden of MAP contamination and this prevalence increases with rainfall. We hypothesize that human exposure to MAP from local water supplies is commonplace and represents a major route for MAP transmission and challenge which, if positively linked to disease pathology, may contribute to the observed high prevalence of IBD in Porto district.
Highlights
Mycobacterium avium subsp. paratuberculosis (MAP), a member of the Mycobacterium avium complex, is the aetiological agent of Johne s Disease (JD), an enteritis affecting ruminant species
Common pathological traits between JD and Crohn s disease (CD) in humans, along with consistent reports of MAP detection in CD patients [6,7] have suggested a possible role of MAP in the pathology of this type of inflammatory bowel disease (IBD)
We found a high frequency of CD patients positive for both MAP and Escherichia coli (EC) DNA in blood, regardless of disease activity, suggesting that both microbial agents may play a part in CD progression
Summary
Mycobacterium avium subsp. paratuberculosis (MAP), a member of the Mycobacterium avium complex, is the aetiological agent of Johne s Disease (JD), an enteritis affecting ruminant species (bovine, ovine and caprine). The aetiology of IBD (including CD) is likely to be multifactorial including the presence of host genetic (and epigenetic) susceptibility traits [9,10] , composition changes in gut microbiota (dysbiosis) and long term colonization/ chronic exposure to particular pathobionts that include MAP and other species such as adherent-invasive Escherichia coli (EC) [7,11,12,13,14] These indications are supported from studies showing significant influencing factors in disease progression include diet and associated exposure to particular water and soil environments, many of which contain MAP and EC, and the long-term remission observed in a number of patients receiving either faecal transplantation and/or anti-MAP therapy [15]. The current evidence suggests that MAP may represent only one possible aetiological agent and that a variety of etiological factors contribute singular aspects to the triggering of this syndrome which in themselves exert diverse degrees of influence on individual hosts depending on existing susceptibilities
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
