Evidence of Linezolid Resistance and Virulence Factors in Enterococcus spp. Isolates from Wild and Domestic Ruminants, Italy

Abstract

The aim of this study was to evaluate the resistance patterns against selected critically and highly important antibiotics (quinupristin/dalfopristin, vancomycin, and linezolid) in 48 Enterococcus isolates obtained from wild (red deer and Apennine chamois) and domestic (cattle, sheep, and goats) ruminants living with varying degrees of sympatry in the protected area of Maiella National Park (central Italy). According to CLSI breakpoints, 9 out of 48 isolates (18.8%) showed resistance to at least one antibiotic. One Apennine chamois isolate was resistant to all tested antibiotics. The PCR screening of related resistance genes highlighted the occurrence of msrC or cfrD in seven Enterococcus resistant isolates. In addition, msrC and vanC genes were amplified in susceptible isolates. Specific sequences of virulence genes (gelE, ace, efa, asa1, and esp) related to pathogenic enterococci in humans were amplified in 21/48 isolates (43.75%), belonging mostly to wild animals (15/21; 71.42%). This is the first report of linezolid-resistant enterococci harboring virulence genes in Italian wildlife with special regard to the red deer and Apennine chamois species. The results allow us to evaluate the potential role of wild animals as indicators of antibiotic resistance in environments with different levels of anthropic pressure.

Antibiotic Resistance Profiles and ARG Detection from Isolated Bacteria in a Culture-Dependent Study at the Codfish Industry Level

“…also presented wide resistance to the linezolid molecule, which was added by the EMA in the CIA lists, and for this reason, it is not indicated for therapeutic purposes in veterinary medicine. Similar AST results were also observed in other Enterococci strains isolated from wild mammalian feces [ 47 ]. These findings can be explained by the high impacts of anthropic activities and their ecological repercussions on humans and wildlife.…”

An in‐house 45‐plex array for the detection of antimicrobial resistance genes in Gram‐positive bacteria

“…And, msrC has been described in Q/ d ‐susceptible isolates, however first reported as being specifically found in resistant E. faecium . This suggests that it might be silent or involved in resistance to other antibiotics (Smoglica et al, 2022 ) such as macrolides (Portillo et al, 2000 ; Zaheer et al, 2020 ). Therefore, msrA which shares significant sequence identity with msrC has been reported to confer macrolides‐streptogramin B resistance in staphylococci and could be an interesting future target to investigate erythromycin and/or Q/D phenotypic resistances (Reynolds & Cove, 2005 ).…”

“…And, msrC has been described in Q/D-susceptible isolates, however first reported as being specifically found in resistant E. faecium. This suggests that it might be silent or involved in resistance to other antibiotics (Smoglica et al, 2022) such as macrolides (Portillo et al, 2000;Zaheer et al, 2020).…”

Virulence genes and antimicrobial resistance in <i>Enterococcus</i> strains isolated from dogs and cats in Northeast China

“…Vancomycin is considered the last line of defense for enterococcal therapy and the advent of VRE presents an even greater challenge. The use of avoparcin was discontinued as a precautionary measure [ 37 ] and the study of linezolid and quinupristin-dalfopristin as alternative molecules for VRE infection [ 51 ] all aim to avoid the development of drug resistance, but they do not achieve complete blockage.…”