An electronmicroscopic study of the interaction of Burkholderia pseudomallei and human macrophages

Nathan, Sakthi A., and Puthucheary, S.D., (2005) An electronmicroscopic study of the interaction of Burkholderia pseudomallei and human macrophages. Malaysian Journal of Pathology, 27 (1). pp. 3-7. ISSN 0126-8635

Preview

PDF - Requires a PDF viewer such as GSview, Xpdf or Adobe Acrobat Reader
476Kb

Affiliations

University of Malaya. Faculty of Medicine. Dept. of Medical Microbiology
University of Malaya. Faculty of Medicine. Dept. of Medical Microbiology

Abstract

B. pseudomallei has been shown to persist intracellularly in melioidosis patients until reactivated by decreasing immunocompetence. We have shown by transmission electron microscopy the internalization of B. pseudomallei by human macrophages via conventional phagocytosis enclosed within membrane-bound vacuoles or phagosomes. Ferritin labeled lysosomes provided evidence of phagosome-lysosome fusion. Ingested bacilli were designated as “intact” or “damaged” on the basis of their ultrastructural features. An intact bacterium was seen with low electron opaque central nuclear region surrounded by dense bacterial cytoplasm, bounded externally by bacterial plasma membrane and cell wall. In contrast, B. pseudomallei were considered damaged when seen with cavitation within the central nuclear region, separation of bacterial cytoplasm from the cell wall, herniation of cytoplasmic contents and lamination of bacterial cell wall and its surrounding electron transparent zone. Our observations indicate that the microbicidal mechanism(s) in B. pseudomalleiinfected macrophages failed to ensure complete clearance of the organism and this failure probably facilitates intracellular persistence and proliferation, and this may be one of the survival strategies adopted by this organism.

Item Type:

Journal

Additional Information:

This study was funded by IRPA Grant 06-02-03-0171 from the Ministry of Science and Technology, Malaysia. (Medical Ethics Committee ref. no. 260.1; 14 August, 2002). We are deeply grateful to all staff of the Electron Microscopy Unit (UM and IMR) for valuable technical assistance.

Keywords:

B.pseudomallei, human macrophages, intracellular survival

Subjects:

R Medicine, Dentistry, Pharmacy, Nursing

ID Code:

1827