Molecular diversity assessed by VNTR and IS1296 typing of historical Mycoplasma mycoides subsp. mycoides SC strains.
The last case of Contagious Bovine Pleuropneumonia (CBPP), caused by Mycoplasma mycoides subsp. mycoides SC (MmmSC), in Europe was reported in Portugal in 1999. However, in view of its insidious nature, it is still possible that CBPP could re-emerge. Despite differences in animal host and geographical origin, most of the European MmmSC field isolates were traditionally considered to be very homogeneous. In the present study we performed a retrospective variable-number tandem repeat (VNTR) and IS1296 genotyping analysis of 65 MmmSC field isolates associated to the last CBPP outbreaks that occurred in Portugal in order to elucidate their intra-specific genetic variability. A 8.8 kb region and two VNTR loci (VNTR4 and VNTR5) were analyzed for polymorphisms by PCR amplification. All but one strain presented the same IS1296 profile, in contrast with the VNTR genotyping that confirmed some diversity of Portuguese strains showing VNTR4, the most discriminatory one, four different patterns. VNTR4 type "9" (numbering according to the estimated number of repeats) was the most predominant one mainly in the Entre Douro-Minho region. All isolates from one geographic region (Beira Litoral) presented VNTR4 type "8" suggesting the existence of a region-specific VNTR. These facts raise the hypothesis that at least two CBPP re-emergence events could have occurred in Portugal since 1983 after 30 years of silence. This aspect represents a major concern and is a major reason for the maintenance of intensive research on this disease.
Varela
Filipa
F
Instituto Nacional de Recursos Biológicos, I.P. - Laboratório Nacional de Investigação Veterinária (INRB, I.P. - LNIV), Estrada de Benfica 701, 1549-011 Lisboa, Portugal.
Inácio
João
J
Botelho
Ana
A
D000818:Animals; D001483:Base Sequence; D014644:Genetic Variation; D005838:Genotype; D018598:Minisatellite Repeats / Q000235:genetics*; D008969:Molecular Sequence Data; D009176:Mycoplasma mycoides / Q000235:genetics* / Q000302:isolation & purification; D012189:Retrospective Studies; D016415:Sequence Alignment