Some minor errours in Methods part Akihiro Ohkado, Research Institute of Tuberculosis, Japan Anti-Tuberculosis Association 10 May 2010 We noticed some minor errours of the units described in the last two sentences of the third paragraph under Methods part of this manuscript. The units described in the sentences, "ml", "mM", and "uC" should read as "μl", "μM", and "°C" respectively. The full two sentences, therefore, should read as "In brief, the PCR mixture was prepared in a 20 μl volume with GC PCR buffer I, 0.5 U Ex Taq, 200 μM each of four dNTPs, 0.5 μM each of the primer set and 10 ng template DNA. PCR was carried out for all loci under the following conditions: initial denaturation at 94 °C for 5 minutes, and then 35 cycles of 94 °C for 30 seconds, 63 °C for 30 seconds and 72 °C for 3 minutes, followed by a final extension at 72 °C for 7 minutes ." We do apologize to readers for any misunderstanding caused by these errours. Competing interests none.