TABLE 1.

Position of mutations in isolates as determined by DNA sequencing

Mutation position	Nucleotide change	Amino acid change	No. of mutations in this study
531	TCG→TTG	Ser→Leu	23
531	TCG→TGG	Ser→Trp	4
526	CAC→TAC	His→Tyr	6
526	CAC→GAC	His→Asp	3
526	CAC→CTC	His→Leu	1
526	CAC→TGC	His→Cys	1
516	GAC→GTC	Asp→Val	6
516	GAC→TTC	Asp→Phe	1
511	CTG→CCG	Leu→Pro	1