Open AccessHuman influence and biotic homogenization drive the distribution of E scherichia coli virulence genes in natural habitats
Author(s) -
Cabal Adriana,
Vicente Joaquin,
Alvarez Julio,
Barasona Jose Angel,
Boadella Mariana,
Dominguez Lucas,
Gortazar Christian
Publication year - 2017
Publication title -
microbiologyopen
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.881
H-Index - 36
ISSN - 2045-8827
DOI - 10.1002/mbo3.445
Subject(s) - virulence , biology , serotype , feces , escherichia coli , ungulate , gene , microbiology and biotechnology , wild boar , shiga toxin , toxin , habitat , genetics , ecology
Cattle are the main reservoirs for Shiga‐toxin‐producing E scherichia coli ( STEC ), the only known zoonotic intestinal E. coli pathotype. However, there are other intestinal pathotypes that can cause disease in humans, whose presence has been seldom investigated. Thus, our aim was to identify the effects of anthropic pressure and of wild and domestic ungulate abundance on the distribution and diversity of the main human E. coli pathotypes and nine of their representative virulence genes ( VG s). We used a quantitative real‐time PCR (qPCR) for the direct detection and quantification of the genus‐specific gene uid A, nine E. coli VGs ( stx1 , sxt 2, eae , ehx A, agg R, est , elt , bfp A, inv A), as well as four genes related to O157:H7 ( rfb O157 , fli C H7 ) and O104:H4 ( wzx O104 , fli C H4 ) serotypes in animals (feces from deer, cattle, and wild boar) and water samples collected in three areas of Doñana National Park (DNP), Spain. Eight of the nine VGs were detected, being inv A, eae , and stx 2 followed by stx 1, agg R, and ehx A the most abundant ones. In quantitative terms (gene copies per mg of sample), stx 1 and stx 2 gave the highest values. Significant differences were seen regarding VGs in the three animal species in the three sampled areas. The serotype‐related genes were found in all but one sample types. In general, VGs were more diverse and abundant in the northern part of the Park, where the surface waters are more contaminated by human waste and farms. In the current study, we demonstrated that human influence is more relevant than host species in shaping the E. coli VGs spatial pattern and diversity in DNP. In addition, wildlife could be potential reservoirs for other pathotypes different from STEC, however further isolation steps would be needed to completely characterize those E. coli .