The results revealed two distinct groups of strains (Nakornpathom-Nakornsawan and Suphanburi-Angthong) as shown by FST of 0.1444 (Pb0.01), RST of 0.2195 (Pb0.01) and a phylogenic tree. Genetic variation within populations was moderate (A= 4.67–12.17; Ae= 3.15–5.80; Ar= 4.67–9.65; Ho= 0.50–0.69; He= 0.67–0.80).