High prevalence and diversity of Extended-Spectrum β-Lactamase and emergence of Carbapenemase producingEnterobacteriaceaespp in wildlife in Catalonia

Abstract

19In wildlife, most of the studies focused on antimicrobial resistance (AMR) describe 20 Escherichia coli as the principal indicator of the selective pressure. In the present study, 21 new species of Enterobacteriaceae with a large panel of cephalosporin resistant (CR) 22 genes have been isolated from wildlife in Catalonia. A total of 307 wild animals were 23 examined to determine CR enterobacteria prevalence, AMR phenotypes and common 24 carbapenem and CR gene expression. The overall prevalence of CR-phenotype was 25 13% (40/307): 17.3% in wild mammals (18/104) and 11.5% in wild birds (22/191) 26 (p<0.01)). Hedgehogs presented the largest prevalence with 13.5% (14/104) of the 27 mammal specimens, followed by raptors with 7.3% (14/191) of the total bird specimens. 28Although CR E. coli was obtained most frequently (45%), other CR- 29Enterobacteriaceae spp like Klebsiella pneumoniae (20%), Citrobacter freundii (15%), 30 Enterobacter cloacae (5%), Proteus mirabilis (5%), Providencia spp (5%) and Serratia 31 marcescens (2.5%) were isolated. A high diversity of CR genes was identified among 32 the isolates, with 50% yielding blaCMY-2, 23% blaSHV-12, 20% blaCMY-1 and 18% 33 blaCTX-M-15. Additionally, new CR-gene variants and resistance to carbapenems 34 associated to OXA-48 were found. Most of the CR isolates, principally K. pneumoniae 35 and C. freundii, were multiresistant with co-resistance to fluoroquinolones, tetracycline, 36 sulphonamides and aminoglycosides. This study describes for the first time in wildlife a 37 high prevalence of Enterobacteriaceae spp harbouring a large variety of carbapenem 38 and CR genes frequently associated to nosocomial human infections. Implementation of 39 control measures to reduce the impact of anthropogenic pressure in the environment is 40 urgently needed. 41 In the last decades, the prevalence of opportunistic and antimicrobial resistant (AMR) 44 bacteria associated with nosocomial infections has suffered an important increase in 45 hospital settings. The overuse of antibiotics in human and veterinary medicine have led 46 to the spread of AMR pathogens, becoming a global health problem [1]. 47 Extended-spectrum β-lactamases (ESBLs) and plasmid-mediated AmpC-type β-48 lactamases (pAmpC) are the most common enzymes that confer resistance to broad-49 spectrum cephalosporins among members of the family Enterobacteriaceae. These β-50 lactamases have extensively diversified in response to the clinical use of new generation 51 drugs: cephalosporins, carbapenems and monobactams [2]. These enzymes are mostly 52 encoded by genes located in plasmids that can be horizontally transferred to different 53 bacteria genera [1]. Carbapenems are last-line beta-lactam antibiotics with the broadest 54 spectrum of activity. Unfortunately, carbapenems nowadays are commonly used in 55 hospital settings for the treatment of life-threatening infections caused by cephalosporin 56 resistant (CR) Enterobacteriaceae. However, the emergence of resistance to 57 carbapenems mediated by the produ...