Genotype distribution of Chinese Mycoplasma bovis isolates and their evolutionary relationship to strains from other countries

Abstract

This study was undertaken to determine the genotypic distribution of Chinese M. bovis strains and their similarity to isolates from other countries. Two multilocus sequence typing (MLST) schemes (MLST-1 and MLST-2) and pulsed field gel electrophoresis (PFGE) were used to compare 44 Chinese strains and the M. bovis type strain PG45. The results showed a high genetic homogeneity of Chinese isolates; 43 of 44 (97.7%) Chinese isolates were identified as ST-10 and as ST-34 by MLST-1, while for MLST-2 42 of 44 (95.5%) were identified as ST-10 with the two remaining isolates of ST-32 and ST43. PFGE clustered 42 of 44 (95.5%) of the Chinese isolates into PT-I. The overall agreement rate between the three typing methods was 97.8% (95% CI:86.8-99.9%). The type strain PG45 was identified as a unique type by all three methods. When the MLST-2 scheme was further used to analyze 16 isolates of Australian and Israeli origin ST-10 was more dominant among Australian isolates (7/8), compared with those from Israel (3/8). The evolutionary relationship of the 60 isolates typed in this study assessed together with 206 additional isolates retrieved from pubmlst/mbovis database analyzed by geoBURST Minimum spanning tree (MST) confirmed that the Chinese, Israeli and Australian M. bovis isolates typed in this study that were predominantly ST-10, were clustered in CC3 with isolates originating from the USA. Our results suggest that ST-10 is an emerging clone of M. bovis population. We hypothesized that the widespread distribution of this type is a result of global livestock movements. These findings will help further the understanding of the global evolution of M. bovis and development of novel vaccines against M. bovis.

A review of mycoplasma diagnostics in cattle

“…However with little information available regarding the circumstances surrounding their isolation, there may be other aspects associated with these isolates, which attributed to the genetic diversity amongst this group. Similar findings were presented by Menghwar et al75 who also used an MLST scheme to compare M. bovis isolates from China, Israel, and Australia. Isolates from these 3 countries clustered together as a single dominant clone, which was the same sequence type as identified byRosales et al 74 While typing methods for Mycoplasma spp.…”

“…As a result, when these diagnostic methods are used concurrently there is often a much higher prevalence of M. bovis positive animals detected by ELISA than by PCR or culture. 101 itive by ELISA in serum samples (75,50, and 55%) than by culture from samples taken from the nasal cavity (52, 30, and 27%). 104 These studies demonstrate that while the number of animals exposed to M. bovis may be high, the proportion of animals that succumb to disease or are actively shedding the pathogen is frequently much lower.…”

Multi-locus sequence typing of Mycoplasma bovis to assess its genetic diversity from 2009-2018 in Ningxia Hui Autonomous Region, China

“…M. bovis can not only cause pneumonia, mastitis, arthritis and otitis, but also induce postpartum infection of the uterus with a mortality rate of 80% [3]. Since there is no effective vaccines and drugs to prevent and cure the disease caused by the pathogen, the incidence of the disease is on the rise [4,5].…”

“…The MLST method compares the nucleic acid sequences of the core fragments of several housekeeping genes, and then compares the diversity of the alleles of the strains. Different strains correspond to different sequence types (ST) [4]. Through the STs of M. bovis pathogens to understand the genetic diversity, population structure and evolutionary trend, which will be beneficial to the control of M. bovis and the development of vaccines, as well as providing a theoretical basis for the prevention and control of M.…”

“…bovis [4]. MLST is a typing technique based on the seven housekeeping genes of M. bovis to study the genetic diversity, population structure and evolutionary trend of M. bovis, including alcohol dehydrogenase-1 (adh-1), glutamate tRNA ligase (gltX), glycerol-3-phosphate dehydrogenase (gpsA), DNA gyrase subunit B (gyrB), phosphate acetyltrans-ferase-2 (pta-2), thymidine kinase (tdk) and transketolase(tkt) [12].…”