alexa Heterogeneity of mycolactones produced by clinical isolates of Mycobacterium ulcerans: implications for virulence.
Microbiology

Microbiology

Journal of Medical Microbiology & Diagnosis

Author(s): MveObiang A, Lee RE, Portaels F, Small PL

Abstract Share this page

Abstract Mycobacterium ulcerans is the causative agent of Buruli ulcer, a severe necrotizing skin disease endemic in tropical countries. Clinical evidence suggests that M. ulcerans isolates from Asia, Mexico, and Australia may be less virulent than isolates from Africa. In vivo studies suggest that mycolactone, a polyketide-derived macrolide toxin, plays a major role in the tissue destruction and immune suppression which occur in cases of Buruli ulcer. Mycolactones were extracted from 34 isolates of M. ulcerans representing strains from Africa, Malaysia, Asia, Australia, and Mexico. Thin-layer chromatography, mass spectroscopic analysis, and cytopathic assays of partially purified mycolactones from these isolates revealed that M. ulcerans produces a heterogeneous mixture of mycolactone variants. Mycolactone A/B, the most biologically active mycolactone species, was identified by mass spectroscopy as [M(+)Na](+) at m/z 765.5 in all cytotoxic isolates except for those from Mexico. Mycolactone C [M+Na](+) at m/z 726.3 was the dominant mycolactone species in eight Australian isolates, and mycolactone D [M+Na](+) m/z 781.2 was characteristic of two Asian strains. Mycolactone species are conserved within specific geographic areas, suggesting that there may be a correlation between mycolactone profile and virulence. In addition, the core lactone, [M+Na](+) m/z 447.4, was identified as a minor species, supporting the hypothesis that mycolactones are synthesized by two polyketide synthases. A cytopathic assay of the core lactone showed that this molecule is sufficient for cytotoxicity, although it is much less potent than the complete mycolactone.
This article was published in Infect Immun and referenced in Journal of Medical Microbiology & Diagnosis

Relevant Expert PPTs

Relevant Speaker PPTs

Recommended Conferences

Relevant Topics

Peer Reviewed Journals
 
Make the best use of Scientific Research and information from our 700 + peer reviewed, Open Access Journals
International Conferences 2017-18
 
Meet Inspiring Speakers and Experts at our 3000+ Global Annual Meetings

Contact Us

 
© 2008-2017 OMICS International - Open Access Publisher. Best viewed in Mozilla Firefox | Google Chrome | Above IE 7.0 version
adwords