Data from: Phylogeny of Mycoplasma bovis isolates from Hungary based on multi locus sequence typing and multiple-locus variable-number tandem repeat analysis

Background: Mycoplasma bovis is an important pathogen causing pneumonia, mastitis and arthritis in cattle worldwide. As this agent is primarily transmitted by direct contact and spread through animal movements, efficient genotyping systems are essential for the monitoring of the disease and for epidemiological investigations. The aim of this study was to compare and evaluate the multi locus sequence typing (MLST) and the multiple-locus variable-number tandem-repeat (VNTR) analysis (MLVA) through the genetic characterization of M. bovis isolates from Hungary. Results: Thirty one Hungarian M. bovis isolates grouped into two clades by MLST. Two strains had the same sequence type (ST) as reference strain PG45, while the other twenty nine Hungarian isolates formed a novel clade comprising five subclades. Isolates originating from the same herds had the same STs except for one case. The same isolates formed two main clades and several subclades and branches by MLVA. One clade contained the reference strain PG45 and three isolates, while the other main clade comprised the rest of the strains. Within-herd strain divergence was also detected by MLVA. Little congruence was found between the results of the two typing systems. Conclusions: MLST is generally considered an intermediate scale typing method and it was found to be discriminatory among the Hungarian M. bovis isolates. MLVA proved to be an appropriate fine scale typing tool for M. bovis as this method was able to distinguish closely related strains isolated from the same farm. We recommend the combined use of the two methods for the genotyping of M. bovis isolates. Strains have to be characterized first by MLST followed by the fine scale typing of identical STs with MLVA.

背景：牛支原体（Mycoplasma bovis）是全球范围内引发牛肺炎、乳腺炎及关节炎的重要病原。该病原体主要通过直接接触传播，并可随动物调运扩散，因此高效的基因分型系统对于该疫病的监测及流行病学调查至关重要。本研究旨在通过对匈牙利分离的牛支原体菌株进行遗传特征分析，比较并评估多位点序列分型（multi locus sequence typing, MLST）与多位点可变数目串联重复序列分析（multiple-locus variable-number tandem-repeat analysis, MLVA）两种分型方法的应用效果。
结果：通过MLST分型，31株匈牙利牛支原体菌株可划分为两个进化分支。其中2株菌株的序列型（sequence type, ST）与参考菌株PG45一致，剩余29株匈牙利分离菌株构成一个包含5个亚分支的全新进化分支。除1个案例外，同一牛群分离的菌株具有相同的序列型。通过MLVA分型，同一组菌株可划分为两个主要进化分支及多个亚分支与独立分支。其中一个分支包含参考菌株PG45及另外3株菌株，另一主要分支则包含其余所有菌株。MLVA分型还检测到了牛群内的菌株遗传差异。两种分型方法的结果一致性较低。
结论：多位点序列分型通常被视为中等分辨率的分型方法，在本次匈牙利牛支原体菌株分型中展现出良好的区分能力。多位点可变数目串联重复序列分析作为一种高分辨率分型工具，可有效区分同一牛场分离的亲缘关系较近的菌株，适用于牛支原体的分型研究。本研究建议联合使用两种分型方法开展牛支原体菌株的基因分型工作：先通过MLST完成菌株分型，再针对具有相同序列型的菌株利用MLVA进行高分辨率分型。