Antimicrobial susceptibility monitoring of Mycoplasma hyopneumoniae isolated from seven European countries during 2015–2016

Mycoplasma hyopneumoniae is the causative agent of porcine enzootic pneumonia, a chronic respiratory disease, causing significant economic losses. Results from 2015?2016 MycoPath pan-European antimicrobial susceptibility monitoring survey M. are presented. In total, 147 isolates Belgium, France, Germany, Great Britain, Hungary, Italy, and Spain were tested. One isolate per farm was retained pigs that had not been recently treated with agents. The minimal inhibitory concentration (MIC) 13 agents determined in central laboratory using broth microdilution method, Friis Medium, incubated at 35 ± 1 °C for 5–12 days. NCTC 10110 used as Quality Control. MIC50/MIC90 (mg/L) values were: enrofloxacin 0.06/1; marbofloxacin 0.06/2; spiramycin 0.06/0.25; tulathromycin ?0.001/0.004; gamithromycin 0.06/0.5; tylosin 0.016/0.06; tilmicosin florfenicol 0.5/1; doxycycline 0.25/1; oxytetracycline 0.25/2; lincomycin tiamulin 0.016/0.06 valnemulin ?0.001/0.004. Compared data 2010 to 2012 study (50 isolates), MIC50/90 results similar majority within two dilution steps, except MIC50 which more than steps higher present study. Between-country comparisons show some differences MIC fluoroquinolones, tylosin, but limited sample size country precludes performing meaningful several countries. Standardized methods interpretive criteria testing veterinary mycoplasmas clearly needed; there currently no clinical breakpoints available facilitate interpretation correlation MICs vivo efficacy.