Species distribution and genes encoding antimicrobial resistance in enterococcus spp. isolates from rabbits residing in diverse ecosystems: A new reservoir of linezolid and vancomycin resistance

Abstract

Aims: Worldwide, studies regarding antimicrobial resistance in rabbits are scarce.In addition, it seems that rearing conditions have important impact on emergence and spread of antimicrobial-resistant bacteria. Thus, the authors sought to (1) assess the role of rabbits residing across diverse ecosystems as potential reservoirs of antimicrobial-resistant enterococci and (2) investigate the genetic background of detected resistances. Methods and Results:Faecal samples from 60 healthy farmed rabbits (one farm), 35 laboratory rabbits and 31 wild rabbits were analysed. Overall, 97 enterococci isolates were accumulated, as follows: 44 E. faecium, 37 E. faecalis, 7 E. gallinarum, 5 E. durans and 4 E. avium. E. faecalis isolates were statistically associated with farm rabbits and wild rabbits (p < 0.05). High rates of resistance were observed for tetracycline (60.8%; tetM [n = 48; 81.3%], tetO [n = 7; 11.8%] and tetL [n = 1; 1.7%]), erythromycin (43.3%; msr(A) [n = 14; 33.3%] and ermB [n = 13; 31%]), ampicillin (29.9%), streptomycin (26.8%; ant(6)-Ia [n = 3, 11.5%]) and vancomycin (21.6%; vanA [one E. faecium + one E. faecalis; 9.5%]). Low frequencies of resistance were observed for teicoplanin (9.2%), linezolid (8.2%), ciprofloxacin (7.2%) and gentamicin (1%; aac(6′)-Ie-aph(2″)-Ia). Resistance to ampicillin and vancomycin was associated with laboratory rabbits (p < 0.05). Int-Tn (Tn916/1545) was detected in 27 (27.8%) isolates, of which 10 isolates co-harboured tetM and ermB genes, while 16 comprised tetM. Conclusion:Findings indicate that clinically relevant enterococci species isolated from rabbits are frequently resistant to antimicrobials and harbour a range of genes associated with the Tn916/1545 family.Significance and Impact of the study: This study highlights the high rates of antimicrobial-resistant enterococci from rabbits and the occurrence of both vancomycin-and linezolid-resistant isolates, potentially representing a very serious threat to human and animal health.

Selection and Characterization of Bacteriocinogenic Lactic Acid Bacteria from the Intestine of Gilthead Seabream (Sparus aurata) and Whiting Fish (Merlangius merlangus): Promising Strains for Aquaculture Probiotic and Food Bio-Preservation

“…and other LAB: hyl (hyaluronidase), esp (enterococcal surface protein), geIE (gelatinase), agg (aggregation substance), ace (collagen adhesion), efA fs (cell wall adhesion), CylL L/s (cytolysin), cob (sex pheromones), cpd (sex pheromones), and ccf (sex pheromones) [ 27 ]. For antimicrobial resistant isolates, genes encoding a corresponding resistance marker were detected by PCR: gentamicin/kanamycin/tobramycin ( aac (6’)-Ia- aph (2”)-Ie); streptomycin ( ant (6)-Ia), erythromycin ( erm (B), erm (A), erm (C), msr (A), and mef (A/E)); tetracycline ( tet (M), tet (L), tet (O), tet (K), and tet (S)); vancomycin/teicoplanin ( van A, van B); and linezolid ( optr A), as reported previously [ 35 , 36 , 37 , 38 ]. Positive controls from previously characterized S. aureus and enterococci strains [ 25 , 35 , 36 , 38 , 39 , 40 , 41 , 42 , 43 ] were used in all PCR experiments.…”

Antibiotic resistance spectrums of Escherichia coli and Enterococcus spp. strains against commonly used antimicrobials from commercial meat-rabbit farms in Chengdu City, Southwest China

“…It is important to note that the vancomycin-resistant Enterococcus spp. have been confirmed in food-producing animals ( 14 , 15 ). Thus, increasing public attention should be paid toward these opportunistic pathogens of animal origin.…”

“…Similar ARG distribution among resistant E. coli or Enterococcus spp. has been also found in farmed or wild rabbits, which may be attributed to environmental antibiotics co-selection ( 9 , 15 , 19 , 41 ). Particularly, some resistant bacteria only carried a small number of ARGs (for example, fexA, qnrD, tetB, tetM , and aac[6 ′ ]-lb ) or none at all, suggesting that certain ARG-independent mechanisms for antimicrobial resistance may be implicated for these bacteria ( 34 , 35 ).…”

“…One limitation of the current study is the unexpanded AMR spectrum analysis for other groups of antibiotics, such as cephalosporins (e.g., ceftiofur), macrolides (e.g., azithromycin), sulfonamides (e.g., sulfadiazine/trimethoprim), and tricyclic glycopeptides (e.g., vancomycin), although they are rarely or never used in local rabbit farming practices. Second, the influence determinants involving antibiotic usage and consumption, bacteria genetic lineages, and biosecurity measures ( 15 , 30 , 31 , 37 ) should be correlated with the emergence and enhancement of antibiotic resistance in further study. Even so, our findings provided a novel perspective on the impact of commonly used antimicrobials in shaping distinctive AMR spectrums and the increasing level of antibiotic resistance among indicator bacteria in meat-rabbit farming practices.…”

Safety and efficacy of a feed additive consisting of Lacticaseibacillus casei IDAC 210415‐01, Limosilactobacillus fermentum IDAC 210415‐02, Levilactobacillus brevis IDAC 051120‐02 and Enterococcus faecium IDAC 181218‐03 (K‐9 Heritage Probiotic Blend®) for dogs (CanBiocin Inc.)

“…12 ■■■■■ 13 No hits of concern were identified for the strains L. casei IDAC 210415‐01, L. fermentum IDAC 210415‐02 and L. brevis IDAC 051120‐02. In the genome of the strain E. faecium IDAC 181218‐03 it was identified the resistance determinant tet (M) which is considered an acquired gene in Enterococcus and in other diverse genus (Jones et al., 2006 ; Flórez et al., 2008 ; León‐Sampedro et al., 2016 ; Lengliz et al., 2022 ). This resistance determinant codifies for a well‐characterised ribosome protection protein known to confer resistance to tetracycline by a direct mechanism of action to dislodge and release tetracycline from the ribosome.…”