Minimal Inhibitory Concentration of Seven Antimicrobials to and Isolates from Six European Countries

and are bacterial pathogens that cause disease in poultry, adversely affecting their health and welfare, and are a financial burden on producers. This manuscript describes the results of the MycoPath project that is the first international antimicrobial susceptibility programme for mycoplasma pathogens isolated from poultry. Improved comparative analysis of minimal inhibitory concentration (MIC) results from participating countries was facilitated by using one laboratory determining all MICs. Chicken and turkey isolates were obtained from France, Germany, Great Britain, Hungary, Italy and Spain during 2014-2016. One isolate per farm was retained. The MIC of seven antimicrobial agents was determined using a broth microdilution method, with Friis Medium () or Modified Chanock's Medium (). Of the 222 isolates recovered, 82 were and 130 were MIC values were 0.12/0.5, 2/8, 0.5/4, 0.12/>64, 0.008/0.062, 0.008/32, 0.062/4 mg/l for doxycycline, enrofloxacin, oxytetracycline, spiramycin, tiamulin, tilmicosin and tylosin, respectively. For , the values were 0.5/1, 8/16, 0.5/1, 0.5/8, 0.25/0.5, 0.062/2 and 0.062/16 mg/l respectively A bimodal MIC distribution for the fluoroquinolone (enrofloxacin) and the macrolides (spiramycin, tilmicosin and tylosin) indicate that both species have sub-populations that are less susceptible to those antimicrobials. Some differences in susceptibilities were observed according to host species, species, and country of origin. This study provides a baseline of novel data for future monitoring of antimicrobial resistance in poultry species. Additionally, this information will facilitate the selection of the antimicrobial agents most likely to be effective, thus ensuring their minimal use with targeted and correct therapeutic treatments. First large-scale pan-European collection of representative and isolates.MIC values assessed in central laboratory for and from chickens and turkeys.Range of MIC values for 82 and 130 isolates to seven licenced antibiotics shown.Data can be used to help determine and veterinary-specific breakpoints.