Limitations of Spoligotyping and Variable-Number Tandem-Repeat Typing for Molecular Tracing of Mycobacterium bovis in a High-Diversity Setting†

This study describes the attempt to trace the first Mycobacterium bovis outbreak in alpacas (Lama pacos) in Spain by spoligotyping and variable-number tandem-repeat (VNTR) analysis. Due to high genotype diversity, no matching source was identified, but local expansion of a clonal group was found and its significance for molecular tracing is discussed. Mycobacterium bovis is the etiological agent of bovine tuber-culosis, but it can affect other domestic animals and wildlife. Molecular typing methods such as spoligotyping (17) and mul-tilocus variable number tandem repeat (VNTR) analysis (10, 29) are wildly used to clarify epidemiological relations between outbreaks. Recently, three cases of M. bovis in alpacas (Lama pacos) have been reported as the first description of tubercu-losis in this animal species in Spain (11). Since trade with camelids is increasing and scarce legislation addressing tuber-culosis in these animals is given, a follow-up by molecular typing was deemed advisable to obtain insight into its epide