Bell-Rogers Patricia, Parker Lois, Cai Hugh Y
Animal Health Laboratory, Laboratory Services Division, University of Guelph, Guelph, Ontario, Canada.
J Vet Diagn Invest. 2018 Jan;30(1):130-135. doi: 10.1177/1040638717731491. Epub 2017 Sep 14.
A total of 217 Mycoplasma bovis isolates cultured from clinical cases in Ontario, Canada, over the past 30 y were selected to be characterized by a multi-locus sequence typing (MLST) method. Eleven housekeeping genes were evaluated for suitability for MLST; 2 loci that had been used in prior MLST schemes, dnaN and metS, along with hsp70 were chosen for further sequence analysis. The remaining loci- adk, efp, gmk, gyrB, polC, rpoB, tpiA, and uvrC genes-were not used because they had little to no sequence variation. The sequence data from the chosen loci ( dnaN, hsp70, metS) generated 28 sequence types (STs), with the 3 loci having 15, 5, and 7 alleles, respectively. These molecular typing results revealed that the STs had a temporal distribution; over the course of 3 decades, some STs disappeared and new STs appeared. Recent isolates had a greater variety of STs, which may indicate that new strains are emerging more rapidly now than in the past.
从加拿大安大略省过去30年临床病例中培养出的总共217株牛支原体分离株，被选择采用多位点序列分型（MLST）方法进行特征分析。评估了11个管家基因对MLST的适用性；选择了先前MLST方案中使用的2个位点dnaN和metS，以及hsp70进行进一步的序列分析。其余位点——adk、efp、gmk、gyrB、polC、rpoB、tpiA和uvrC基因——未被使用，因为它们几乎没有序列变异。所选位点（dnaN、hsp70、metS）的序列数据产生了28种序列类型（STs），这3个位点分别有15、5和7个等位基因。这些分子分型结果显示STs具有时间分布；在30年的时间里，一些STs消失了，新的STs出现了。最近的分离株具有更多样化的STs，这可能表明现在新菌株出现的速度比过去更快。
