IDENTIFICATION AND SUBSPECIFIC DIFFERENTIATION OF MYCOBACTERIUM-SCROFULACEUM BY AUTOMATED SEQUENCING OF A REGION OF THE GENE (HSP65) ENCODING A 65-KILODALTON HEAT-SHOCK PROTEIN

Mycobacterium scrofulaceum is most commonly recovered from children wi th cervical lymphadenitis, although it also accounts for approximately 2% of the mycobacterial infections in AIDS patients. Species assignme nt of M. scrofulaceum isolates by conventional techniques can be diffi cult and time-consuming. To develop a strategy for rapid species assig nment of these organisms, a 360-bp region of the gene (hsp65) encoding a 65-kDa heat shock protein in 37 isolates from diverse sources was s equenced. Eight hsp65 alleles were identified, and these sequences for med phylogenetic clusters and lineages largely distinct from other Myc obacterium species. There was incomplete correlation between serovar d esignation and hsp65 allele assignment. The hsp65 data correlated stro ngly with the results of sequence analysis of the gene coding for 16S rRNA. Automated DNA sequencing of a 360-bp region of the hsp65 gene pr ovides a rapid and unambiguous method for species assignment of these acid-fast organisms for diagnostic purposes.