Identification and characterization of pathogenic and multidrug-resistant bacteria in feral pigeons surrounding a veterinary hospital in Minas Gerais, Brazil

Pigeons are known for their capacity to harbor and spread several zoonotic agents. Studies have suggested that pigeons are also relevant disseminators of multidrug-resistant strains. In this study, pigeons surrounding a veterinary hospital were sampled and tested for the presence of pathogenic Escherichia coli, Salmonella spp., Staphylococcus spp., and Clostridioides (Clostridium) difficile. E. coli isolates from 19 (40.4%) pigeons tested positive for the E. coli heat-stable enterotoxin 1 (EAST1)-encoding gene. The intimin-encoding gene (eae) of enteropathogenicE. coli (EPEC) was found in one isolate (2.1%). Salmonella spp. were found in nine (19.1%) pigeons, all from the first capture event (P < 000.1). S. Typhimurium and S. Heidelberg were isolated from six and three pigeons, respectively. Enterobacterial repetitive intergenic consensus (ERIC-PCR) of the Salmonella spp. isolates suggested that eight of the nine strains had a high genetic similarity, supporting the hypothesis of an outbreak of salmonellosis in these pigeons. Twenty (42.5%) staphylococcal isolates were recovered from 18 (38.3%) pigeons. Eight different species were detected, with S. xylosus being the most frequent. Two (4.3%) C. difficile strains were isolated. Three isolates, one each of S. Typhimurium, S. aureus, and C. difficile, were classified as multidrug-resistant strains. The present research suggested that pigeons residing in urban areas can act as reservoirs and disseminators of pathogenic bacteria, including nosocomial pathogens, such as diarrheagenicE. coli and multidrug-resistant Staphylococcus spp., C. difficile, and Salmonella spp.