High occurrence of carbapenem-resistant Escherichia coli isolates from healthy rabbits (Oryctolagus cuniculus): first report of blaIMI and blaVIM type genes from livestock in Tunisia.

We aimed to study the antibiotic susceptibility and possible occurrence of extended-spectrum beta-lactamases (ESBL)/carbapenemase-producing Escherichia coli isolates collected from rabbits in Tunisia. In all, 35 faecal samples from healthy rabbits were collected from one farm and E. coli were isolated from three media: antibiotic-free TBX agar, TBX+2 mg l-1 cefotaxime and TBX+1 mg l-1 imipenem. In total, 39 E. coli isolates were recovered; the majority showed resistance to at least one antibiotic and none was ESBL producer. Carbapenem resistance was detected in 16 isolates from either selective or un-selective media. Phenotypic methods used to detect carbapenemase production showed two positive isolates by Modified Hodge Test, six metallo-carbapenemase producers (Imipenem disc+EDTA) and all were temocillin resistant (possible OXA-48 carbapenemase). blaVIM and blaIMP type genes were detected in two and one isolates, respectively; one of them harboured both genes. Isolates contained common genes encoding resistance to sulphonamides (sul1, sul2), tetracycline (tetA, tetB, tetC) and fluoroquinolones (qnrS, aac(6')-Ib-cr). Class 1 and 2 integrons were detected in five and four isolates, respectively. These findings highlight the importance of rabbit production as reservoir of carbapenem-resistant E. coli and argument the first report of blaVIM and blaIMP genes in livestock in Tunisia.

Characterization of bacteriocinogenic Enterococcus isolates from wild and laboratory rabbits for the selection of autochthonous probiotic strains in Tunisia.

AIM: The objective of this study was to characterize lactic acid bacteria (LAB) from rabbits to be used as potential autochthonous probiotic. METHODS AND RESULTS: Fifteen faecal samples were collected from wild and laboratory rabbits. One hundred and eight isolates were collected and tested for their inhibitory power against eight pathogenic bacteria. Among them, 43 Enterococcus isolates were able to inhibit at least one pathogen. Enterocine genes entA, entB and entP were detected in 14, 17 and 22 isolates, respectively. These isolates were tested for their antibiotic susceptibility and genes encoding virulence factors. Relevant phenotypes of antibiotic resistance were observed especially for ampicillin, vancomycin and linezolid. The following virulence genes were detected (number of positive isolates): hyl (5), esp (8), gelE (30), agg (2), ace (21), efa (6), CylLL/s (5), cob (26), cpd (32) and ccf (33). Five isolates were considered as safe and showed tolerance to both acid and bile salt. CONCLUSION: Bacteriocinogenic enterococci isolates from rabbits may show relevant resistance phenotypes and virulence factors. In addition, one Enterococcus durans isolate presents promising autochthonous probiotic candidate. SIGNIFICANCE AND IMPACT OF THE STUDY: This study reveals interesting properties for E. durans isolate and supports their utilization as autochthonous probiotic in rabbit husbandry.