Mitochondrial DNA (mtDNA) types based on restriction fragment length polymo
rphism (RFLP) patterns with HaeIII were investigated in clinical isolates o
f Sporothrix schenckii in North and South America. In addition to 14 mtDNA
types (Types 1-14) so far reported, six new mtDNA types, Types 15-20 were f
ound in this study. Type 3 was divided into two subtypes, Subtype 3A and Su
btype 3B based on RFLP with Msp I. Type 14 was also divided into three subt
ypes, Subtype 14A, Subtype 14B anti Subtype 14C based on RFLP with Hha 1. N
ineteen isolates in the United States consisted of 1 isolate of Type 1, 12
of Type 2, 2 of Type 4, 3 of Type 14 (1 of Subtype 14B and 2 of Subtype 14C
) and 1 of Type 15. Twenty nine isolates in Venezuela consisted of 13 of Ty
pe 3 (Subtype 3B), 6 of Type 4, 1 of Type 18, 3 of Type 19 and 6 of Type 20
. Thirteen isolates in Argentina consisted of 2 of Type 3 (Subtype 3A), 4 o
f Type 4, 4 of Type 16 and 3 of Type 17. One isolate in Brazil was Type 3 (
Subtype 3A). Based on the phylogeny of 20 mtDNA types (Types 1-20) construc
ted by estimating sequence divergences of mtDNA, mtDNA types were clustered
into two groups: Group A (Types 1-3,Type Il and Types 14-19) and Group B (
Types 4-10, Types 12-13 and Type 20). These results suggest that S. schenck
ii isolates in North and South America mainly belong to Group A.