Clinical and epidemiological correlates of genotypes within the Mycobacterium avium complex defined by restriction and sequence analysis of hsp65.
Species identification of isolates of the Mycobacterium avium complex (MAC) remains a difficult task. Although M. avium and Mycobacterium intracellulare can be identified with expensive, commercially available probes, many MAC isolates remain unresolved, including those representing Mycobacterium lentiflavum as well as other potentially undefined species. PCR restriction analysis (PRA) of the hsp65 gene has been proposed as a rapid and inexpensive approach. We applied PRA to 278 MAC isolates, including 126 from blood of human immunodeficiency virus (HIV)-infected patients, 59 from sputum of HIV-negative patients with chronic obstructive pulmonary disease, 88 from environmental sources, and 5 pulmonary isolates from a different study. A total of 15 different PRA patterns were observed. For 27 representative isolates, a 441-bp fragment of the hsp65 gene was sequenced; based on 54 polymorphic sites, 18 different alleles were defined, including 12 alleles not previously reported. Species and phylogenetic relationships were more accurately defined by sequencing than by PRA or commercial probe. The distribution of PRA types and, by implication, phylogenetic lineages among blood isolates was significantly different from that for pulmonary and environmental isolates, suggesting that particular lineages have appreciably greater virulence and invasive potential.
Smole
Sandra C
SC
Department of Medicine, Boston University School of Medicine, VA Boston Healthcare System, Boston, Massachusetts 02130, USA.
McAleese
Fionnuala
F
Ngampasutadol
Jutamas
J
Von Reyn
C Fordham
CF
Arbeit
Robert D
RD
D001426:Bacterial Proteins; D015373:Bacterial Typing Techniques; D001483:Base Sequence; D001769:Blood / Q000382:microbiology; D018834:Chaperonin 60; D018833:Chaperonins / Q000235:genetics*; D004251:DNA Transposable Elements; D005838:Genotype; D006801:Humans; D008168:Lung / Q000382:microbiology; D008969:Molecular Sequence Data; D015269:Mycobacterium avium Complex / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D015270:Mycobacterium avium-intracellulare Infection / Q000453:epidemiology* / Q000382:microbiology / Q000503:physiopathology*; D010802:Phylogeny; D016133:Polymerase Chain Reaction / Q000379:methods; D015183:Restriction Mapping; D017422:Sequence Analysis, DNA
D001426:Bacterial Proteins; D018834:Chaperonin 60; D004251:DNA Transposable Elements; C074119:heat-shock protein 65, Mycobacterium; D018833:Chaperonins