AUTHOR=Hao Haihong , Zhou Shengxi , Cheng Guyue , Dai Menghong , Wang Xu , Liu Zhenli , Wang Yulian , Yuan Zonghui 

TITLE=Effect of Tulathromycin on Colonization Resistance, Antimicrobial Resistance, and Virulence of Human Gut Microbiota in Chemostats

JOURNAL=Frontiers in Microbiology

VOLUME=7

YEAR=2016

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2016.00477

DOI=10.3389/fmicb.2016.00477

ISSN=1664-302X

ABSTRACT=<p>To evaluate microbiological safety of tulathromycin on human intestinal bacteria, tulathromycin (0, 0.1, 1, 10, and 100 μg/mL) was added into Chemostats. Before and after drug exposure, we monitored (1) population, SCFA products, antimicrobial resistance, and colonization resistance of gut microbiota, and (2) the antimicrobial resistance genes, transferability, virulent genes, pathogenicity of <italic>Enterococus faecalis</italic>. Results showed that low level of tulathromycin did not exhibit microbiological hazard on resistance selection and colonization resistance. However, high level of tulathromycin (10 and 100 μg/mL) may disturb colonization resistance of human gut microbiota and select antimicrobial resistant <italic>E. faecalis</italic>. Most of the selected resistant <italic>E. faecalis</italic> carried resistant gene of <italic>ermB</italic>, transferable element of Tn<italic>1545</italic> and three virulence genes (<italic>esp, cylA</italic>, and <italic>ace</italic>). One of them (<italic>E. faecalis</italic> 143) was confirmed to have higher horizontal transfer risk and higher pathogenicity. The calculated no observable adverse effect concentration (NOAEC) and microbiological acceptable daily intake (mADI) in our study was 1 μg/mL and 14.66 μg/kg.bw/day, respectively.</p>