Phenotypic and genotypic profiles of antimicrobial resistance (AMR) in Salmonella spp., isolates from faeces of different canine populations of Northern and Central Italy

From March 2012 to September 2012, the faecal samples of 511 dog (237 collected from practitioners in their clinics, 193 collected from kennels and 81 from public recreative areas) underwent microbiological analysis to detect Salmonella spp. Salmonella spp. was isolated from 14 (2.74 %) faecal samples: 3 (0.59%) from samples collected from practitioners in clinics, 8 (1.56 %) from samples collected from kennels and 3 (0.59 %) from samples collected from public recreative areas. The number of positive samples found in this survey reflects epidemiological data for this pathogen in dog. Serotyping is currently in progress. The isolates were tested for their sensitivity to 16 antimicrobial agents by the disk diffusion method (i.e. Kirby-Bauer). Out of 14 isolates, none showed full susceptibility to all the drugs tested. Absence of susceptibility ranged from a minimum of 1 drug to a maximum of 14 drugs. About one-third of the isolates showed absence of susceptibility to nalidixic acid and enrofloxacin. None of the isolates was sensitive to streptomycin. All but one of the isolates were resistant to kanamycin and triple sulfas. Out of 14 isolates, 12 (85.7%) showed AMR. All but one of the isolates were sensitive to sulphamethoxazole + trimethoprim and amoxycillin + clavulanic acid. At the moment is just started the genetic characterization of AMR by the detection (by PCR and sequencing) and analysis of both chromosomal resistance mutations and plasmid-mediated resistance genes. A further aim of this study will be the genetic characterization of selected isolates by Multilocus Sequence Typing (MLST).