“…The initial minimal inhibitory concentration (MIC) of each strain was defined as the lowest concentration of the antibiotic that completely inhibited the growth at the time of colour change in the growth control. Since there are no official breakpoints available for the antibiotic susceptibility testing of M. hyorhinis, previously published breakpoints for M. hyopneumoniae or other porcine respiratory pathogens were used (Hannan et al, 1997;Felde et al, 2020;Vilar o et al, 2020). MIC values ≥4 mg/mL of tylosin, tylvalosin, gamithromycin and lincomycin were considered high (Hannan et al, 1997;Felde et al, 2020), while for tilmicosin and tulathromycin higher breakpoints were suggested, thus MIC values ≥16 mg/mL were considered high (Vilar o et al, 2020).…”