ref1="../../data/saureus/COL.fasta"
ref2="../../data/saureus/JKD6008.fasta"
ref3="../../data/saureus/RF122.fasta"
ref4="../../data/saureus/N315.fasta"

tree="(ref2:0.0359,(((ref1:0,target:0.00028)0.91:0.00153,ref4:0.00323)1:0.03131,ref3:0.0277):0.00135);