Abstract
In wildlife, most of the studies focused on antimicrobial resistance (AMR) describe Escherichia coli as the principal indicator of the selective pressure. In the present study, new species of Enterobacteriaceae with a large panel of cephalosporin resistant (CR) genes have been isolated from wildlife in Catalonia. A total of 307 wild animals were examined to determine CR enterobacteria prevalence, AMR phenotypes and common carbapenem and CR gene expression. The overall prevalence of CR-phenotype was 13% (40/307): 17.3% in wild mammals (18/104) and 11.5% in wild birds (22/191) (p<0.01)). Hedgehogs presented the largest prevalence with 13.5% (14/104) of the mammal specimens, followed by raptors with 7.3% (14/191) of the total bird specimens. Although CR E. coli was obtained most frequently (45%), other CR-Enterobacteriaceae spp like Klebsiella pneumoniae (20%), Citrobacter freundii (15%), Enterobacter cloacae (5%), Proteus mirabilis (5%), Providencia spp (5%) and Serratia marcescens (2.5%) were isolated. A high diversity of CR genes was identified among the isolates, with 50% yielding blaCMY-2, 23% blaSHV-12, 20% blaCMY-1 and 18% blaCTX-M-15. Additionally, new CR-gene variants and resistance to carbapenems associated to OXA-48 were found. Most of the CR isolates, principally K. pneumoniae and C. freundii, were multiresistant with co-resistance to fluoroquinolones, tetracycline, sulphonamides and aminoglycosides. This study describes for the first time in wildlife a high prevalence of Enterobacteriaceae spp harbouring a large variety of carbapenem and CR genes frequently associated to nosocomial human infections. Implementation of control measures to reduce the impact of anthropogenic pressure in the environment is urgently needed.