Detection of Beta-Lactam-Resistant Escherichia coli and Toxigenic Clostridioides difficile Strains in Wild Boars Foraging in an Anthropization Gradient

Abstract

Disease transmission among wild boars, domestic animals and humans is a public health concern, especially in areas with high wild boar densities. In this study, fecal samples of wild boars (n = 200) from different locations of the Metropolitan Area of Barcelona were analyzed by PCR to explore the frequency of β-lactamases and extended cephalosporin and carbapenem resistance genes (ESBLs) in Escherichia coli strains and the presence of toxigenic Clostridioides difficile. The prevalence of genes conferring resistance to β-lactam antimicrobials was 8.0% (16/200): blaCMY-2 (3.0%), blaTEM-1b (2.5%), blaCTX-M-14 (1.0%), blaSHV-28 (1.0%), blaCTX-M-15 (0.5%) and blaCMY-1 (0.5%). Clostridioides difficile TcdA+ was detected in two wild boars (1.0%), which is the first report of this pathogen in wild boars in Spain. Moreover, the wild boars foraging in urban and peri-urban locations were more exposed to AMRB sources than the wild boars dwelling in natural environments. In conclusion, the detection of E. coli carrying ESBL/AmpC genes and toxigenic C. difficile in wild boars foraging in urban areas reinforces the value of this game species as a sentinel of environmental AMRB sources. In addition, these wild boars can be a public and environmental health concern by disseminating AMRB and other zoonotic agents. Although this study provides the first hints of the potential anthropogenic sources of AMR, further efforts should be conducted to identify and control them.

Marina Cerdá was a student of the master0 s degree in Zoonosis and One Health (UAB). Anna Vidal was supported by Universitat Autònoma de Barcelona (PIF-UAB 2015). Laia Aguirre was supported by a collaboration scholarship from the Ministerio de Educación, Cultura y Deporte from the Spanish government (2017–2018). This research was funded by the contracts 13/051, 15/0174 and 16/0243 between the Barcelona City Council and the Wildlife Health Service (SEFaS-UAB). Marta Valldeperes and Raquel Castillo-Contreras benefitted from a PhD grant each (2018FI_B_00978 and 2016FI_B 00425, respectively), financed by the Secretaria d’Universitats i Recerca del Departament d’Economia i Coneixement de la Generalitat de Catalunya and the European Social Fund. Gregorio Mentaberre is a Serra Húnter Fellow.