ANTIMYCOBACTERIAL ACTIVITY OF LECITHIN-CHOLESTEROL LIPOSOMES IN THE PRESENCE OF PHOSPHOLIPASE A₂

Abstract

Tubercle bacilli were preincubated with lecithin-cholesterol liposomes to be subsequently exposed to phospholipase A₂. After further incubation in the environment of acidic buffer, viable units in the final mixture were enumerated by inoculating the serial dilutions of an aliquot onto Kirchner agar medium containing horse serum in 5%. Another aliquot was used for lipid analyses to confirm hydrolysis of lecithin. In addition to this bactericidal type of experiments, bacteriostatic tests were also conducted with Kirchner semi-solid agar medium, into which liposome-treated bacilli were inoculated with the enzyme at a time. Various natural and synthetic lecithins different in constituent fatty acids were employed. The results indicated that toxic fatty acids released from lecithin acted to kill the bacilli or to inhibit their growth.