BERMUDEZ LE, SOSNOWSKA D, MILTNER E, CHACON O, WAGNER D, MCGARVEY J, BROXMEYER L, BARLETTA R; Interscience Conference on Antimicrobial Agents and Chemotherapy (41st : 2001 : Chicago, Ill.).

Abstr Intersci Conf Antimicrob Agents Chemother Intersci Conf Antimicrob Agents Chemother. 2001 Dec 16-19; 41: abstract no. B-1373.

Kuzell Institute, San Francisco, CA

Both M. tuberculosis (MTb) and M. avium (MAC) are human pathogens which can survive intracellularly. Phage TM4 infects both MAC and MTb and can kill both bacteria in vitro after 4 h, but had no effect when added to macrophage monolayers containing intracellular bacteria. We devised a system using Mycobacterium smegmatis to deliver the lytic phage TM4 to the site where both MAC and MTb reside within macrophages based on a fusigenic property of the mycobacterial phagosome. Co-infection of macrophage monolayers with M. smegmatis had no significant impact on the number of intracellular bacteria, but treatment ofMAC-infected and MTb-infected RAW 264.7 mouse peritoneal macrophages with M. smegmatis infected with TM4 resulted in a significant time and titer-dependent (10[5], 10[6] and 10[7] pfu) reduction in viable intracellular bacilli. Addition of 10[6] M. smegmatis infected with 10[7] pfu TM4 to MAC infected macrophages resulted in 0.5 +/- 0.01 reduction after 2 days and 0.8 +/- 0.02 log reduction after 4 days (p < 0.05 vs. controls). Monolayers infected with MTb was associated with 1.0 +/- 0.02 log and 1.8 +/- 0.03 log reduction after 2 days and 4 days respectively (p < 0.05 vs. controls). Time-lapse video microscopy showed that the vacuole containing M. smegmatis harboring TM4 fuses with the vacuole containing MAC in macrophages, with acridine orange serving as marker for acidic vacuoles. The findings identify a novel approach to killing intracellular bacteria such as dormant or latent mycobacteria and warrants study in animal test systems.

Publication Types:

• Meeting Abstracts

Keywords:

• Animals
• Bacteriophages
• Humans
• In Vitro
• Macrophages
• Macrophages, Peritoneal
• Mice
• Mycobacteriophages
• Mycobacterium
• Mycobacterium avium
• Mycobacterium avium-intracellulare Infection
• Mycobacterium smegmatis
• Mycobacterium tuberculosis
• Phagosomes
• Tuberculosis
• Vacuoles
• microbiology
• therapy

Other ID:

• GWAIDS0029905

UI: 102269537

From Meeting Abstracts