Occurrence and Genomic Characterization of ESBL-Producing, MCR-1-Harboring Escherichia coli in Farming Soil.
The emergence and spread of the mobile colistin resistance gene (mcr-1) has become a major global public health concern. So far, this gene has been widely detected in food animals, pets, food, and humans. However, there is little information on the contamination of mcr-1-containing bacteria in farming soils. In August 2016, a survey of ESBL-producing Escherichia coli isolated from farming soils was conducted in Shandong Province, China. We observed colistin resistance in 12 of 53 (22.6%) ESBL-producing Enterobacteriaceae isolates from farming soil. Six mcr-1-positive E. coli strains originating from a livestock-intensive area were found. The isolates belonged to four different STs (ST2060, ST3014, ST6756, and ST1560) and harbored extensive additional resistance genes. An E. coli with blaNDM-1 was also detected in a soil sample from the same area. Comparative whole genome sequencing and S1-PFGE analysis indicated that mcr-1 was chromosomally encoded in four isolates and located on IncHI2 plasmids in two isolates. To our knowledge, we report the first isolation of mcr-1 in ESBL-producing E. coli from farming soils. This work highlights the importance of active surveillance of colistin-resistant organisms in soil. Moreover, investigations addressing the influence of animal manure application on the transmission of mcr-1-producing bacteria are also warranted.
['Zheng|Beiwen|B|', 'Huang|Chen|C|', 'Xu|Hao|H|', 'Guo|Lihua|L|', 'Zhang|Jing|J|', 'Wang|Xin|X|', 'Jiang|Xiawei|X|', 'Yu|Xiao|X|', 'Jin|Linfeng|L|', 'Li|Xuewen|X|', 'Feng|Youjun|Y|', 'Xiao|Yonghong|Y|', 'Li|Lanjuan|L|']
Escherichia coli farming soil mcr-1 animal manure ESBLs