A NEW FLUOROGENIC ASSAY FOR MONITORING AND DETERMINING PLANKTONIC AND BIOFILM FORMS OF PSEUDOMONAS AERUGINOSA VIABLE COUNT IN VITRO

ABSTRACT

A new method was developed to rapidly monitor the Pseudomonas aeruginosa viable counts using alamar blue (AB). The 96-well microtiter plates were used to perform the assay. This procedure is based on fluorogenic measurement as a result of reduction of nonfluorescent AB to red fluorescent form by the viable cells of P. aeruginosa. The correlation between conventional plate count and fluorogenic AB method was highly satisfactory for quantification of planktonic (R² = 0.9487) and biofilm cells of P. aeruginosa (R² = 0.9296).

PRACTICAL APPLICATIONS

The new fluorogenic method can rapidly monitor Pseudomonas aeruginosa counts in vitro with a high correlation with the conventional plating method. The results indicate that fluorogenic method requires much shorter time (2 h) than the conventional plate count (24 h), is a more cost-effective way, quite amenable to high throughput, and continuous monitoring of P. aeruginosa viability is achievable in the kinetic in vitro models without interference with the cell viability.