Feature of Adhesins Produced by Human Clinical Isolates ofMycobacterium intracellulare,Mycobacterium intracellularesubsp.chimaeraand Closely Related Species

TheMycobacterium aviumcomplex includes two closely related species,Mycobacterium aviumandMycobacterium intracellulare. They are opportunistic pathogens in humans and responsible for severe disease in a wide variety of animals. Yet, little is known about factors involved in their pathogenicity. Here, we identified, purified and characterized adhesins belonging to the heparin-binding hemagglutinin (HBHA) and laminin-binding protein (LBP) family fromM. intracellulareATCC13950 and examined clinical isolates from patients with different pathologies associated withM. intracellulareinfection for the presence and conservation of HBHA and LBP. Using a recombinant derivative strain ofM. intracellulareATCC13950 producing green fluorescent protein and luciferase, we found that the addition of heparin inhibited mycobacterial adherence to A549 cells, whereas the addition of laminin enhanced adherence. Both HBHA and LBP were purified by heparin-Sepharose chromatography and their methylation profiles were determined by mass spectrometry. Patients withM. intracellulareinfection mounted strong antibody responses to both proteins. By using PCR and immunoblot analyses, we found that both proteins were highly conserved among all 17 examined clinicalM. intracellulareisolates from patients with diverse disease manifestations, suggesting a conserved role of these adhesins inM. intracellularevirulence in humans and their potential use as a diagnostic tool.