Genomic and antigenic differences between the European and African/Australian clusters of Mycoplasma mycoides subsp. mycoides SC The GenBank accession numbers for the nucleotide sequences determined in this work are: AF165134 for the 3·4 kb HindIII fragment from M. mycoides subsp. mycoides SC strain L2; AF165135 for the analogous locus in strain Afadé (containing lppB and IS1634); and AF1651136 for the DNA segment containing lppB[MmymyLC] and ORF6[MmymyLC] from M. mycoides subsp. mycoides LC strain Y-goat.

Abstract

Mycoplasma mycoides subsp. mycoides small-colony type (SC), the aetiological agent of contagious bovine pleuropneumonia (CBPP), can be grouped into two major, epidemiologically distinct, clusters. One cluster contains strains isolated from different European countries since 1980 and a second cluster contains African and Australian strains collected over the last 50 years. Genetic analysis of representative strains from the two clusters revealed a genomic segment of 884 kb, located close to a copy of IS1296, which is present in all strains of the African cluster but lacking in all strains of the European cluster. This segment contains a copy of IS1634, a gene for a potential lipoprotein, lppB, open reading frames encoding a putative surface-located membrane protein and a hypothetical proline-rich membrane protein, and two open reading frames showing similarity to putative ABC transporters. The product of the lppB gene, lipoprotein B (LppB), has an apparent molecular mass of 70 kDa and was shown to be surface located. It is detected with monospecific antibodies in all strains of the African cluster tested, but not in European-cluster strains. DNA sequence analysis of the splicing site at which European strains differ from African-cluster strains by the lack of the 884 kb segment showed that the European cluster has arisen by deletion from a strain of the African cluster. Hence, M. mycoides subsp. mycoides SC strains isolated in different European countries from the newly reemerging outbreaks of CBPP, which occurred after the eradication of the epizootic in Europe in the middle of the 20th century, represent a phylogenetically newer cluster that has been derived from a strain of the older cluster of M. mycoides subsp. mycoides SC which is still endemic on the African continent.

Genotyping ofMycoplasma mycoidessubsp.mycoidesSC by multilocus sequence analysis allows molecular epidemiology of contagious bovine pleuropneumonia

“…The use of IS1296 as a probe allowed the clear differentiation of recent European strains from those of African origin [7]. The observed difference was explained later on by the identification of an 8.8 kbp deletion in the genome of most MmmSC strains of European origin [43], resulting in a missing IS1296 band. The use of another insertion element, IS1634, also led to different Southern blot profiles [24,46] although the high copy number of this insertion sequence (N = 60), as compared to that of IS1296 (N = 28), gave rise to profiles that were difficult to analyse.…”

Antigenic and genetic characterisation of lipoprotein lppC from Mycoplasma mycoides subsp. mycoides SC

“…The deduced amino acid sequence of LppC showed similarities with the two other known lipoproteins of M. mycoides subsp. mycoides SC, LppB [29] and LppQ [2]. This could explain why antibodies against the N-terminal domain of LppC cross-react slightly with LppB which is present in the type strain and in African and Australian strains.…”

“…mycoides SC strains [1,9]. The group constituting African and Australian strains and the type strain PG1 was also characterised by the presence of a 70 kDa antigen, corresponding to lipoprotein LppB, which was not detected in European strains [9,29]. In addition, two other antigenic proteins have been characterised thus far in M. mycoides subsp.…”

“…The resulting plasmid pJFFLppC-His was verified by restriction enzyme digestion and partial DNA sequencing. Expression and purification of poly-histidine tailed LppC was made as described previously for lipoprotein LppB [29]. The recombinant protein had an apparent molecular mass of approximately 32 kDa (data not shown) which corresponded to the calculated mass of 31.4 kDa for LppCN'-His.…”

“…mycoides SC [29]; LppQ, a 48-kDa lipoprotein that appears to be highly specific for the species M. mycoides subsp. mycoides SC [2]; and Vmm, a variable surface protein of 59 amino acids that undergoes reversible phase variation [18].…”