Project description:Staphylococcus aureus is recognized worldwide as a major pathogen causing clinical or subclinical intramammary infections in all the dairy species (sheep, goats and cows). The present study was designed to comparatively investigate 65 S. aureus isolates recovered from dairy sheep and S. aureus suclinical mastitis from cows (n=21) and goats (n=22), for the presence of 190 putative virulence determinants with a single-dye DNA microarray and PCR. The probes (65 mer) were mainly designed from the S. aureus Mu50. The extracted DNA of each strain was labelled with Cy5. The microarray results were validated with PCR.The genomic comparative study with the DNA microarrays showed lineage and species specificity genes leading to the host-specific pathogenic traits of S. aureus in dairy species.
Project description:Mycoplasma capricolum subsp. capricolum is one of the causative agents of contagious agalactia (CA). Nevertheless, there is still a lack of information about its antimicrobial susceptibility and genetic characteristics. Therefore, the aim of this work was to study the antimicrobial and genetic variability of different Mycoplasma capricolum subsp. capricolum field isolates. For this purpose, the growth inhibition effect of 18 antimicrobials and a multilocus sequence typing (MLST) scheme based on five housekeeping genes (fusA, glpQ, gyrB, lepA and rpoB) were performed on 32 selected field isolates from Italy and Spain.The results showed a wide range of growth inhibitory effects for almost all the antimicrobials studied. Macrolides presented lower efficacy inhibiting Mcc growth than in previous works performed on other CA-causative mycoplasmas. Erythromycin was not able to inhibit the growth of any of the studied strains, contrary to doxycycline, which inhibited the growth of all of them from low concentrations. On the other hand, the study of the concatenated genes revealed a high genetic variability among the different Mcc isolates. Hence, these genetic variations were greater than the ones reported in prior works on other mycoplasma species.
