The use of luminous bacteria for determination of phagocytosis

The existing methods for phagocytosis evaluation are inadequate for assessing all the real events occurring during phagocytosis, or for continuously following the kinetics of the process. Our purpose is to establish the use of luminous bacteria as an object for phagocytosis. The bioluminescence test offers an easy and simple method to determine the kinetics of phagocytosis by following the luminescence of the bacteria. The terrestrial luminous bacteria Vibrio cholerae var. albensis are readily phagocytosed by polymorphonuclear (PMN) cells. The correlation coefficient between the decrease in luminescence and the decrease in viable count is 0.999. The rate of decrease in luminescence and the residual level of luminescence after 60 min of phagocytosis are proportional to the rate of increase in phagocytosis induced chemiluminescence, and to its maximal level, respectively. Opsonization requirements are comparable in both tests. Different inhibitors of the phagocytosis process caused similar changes in the rates of the bio- and chemiluminescence (correlation coefficient 0.974), and in the luminescence maximal level (correlation coefficient 0.804). The validity of the bioluminescence assay being proved, it is suggested as an alternative assay for phagocytosis assessment.