Comparison of BCYE and BMPA media on recovery rate of Legionella pneumophila

Abstract

Background: Legionella pneumophila (L. pneumophila) has been known as the etiology of legionellosis; they live in aquatic environment, warm and moist. Culture method using specific medium remains as the gold standard in the identification of L. pneumophila. This study aimed to compare the recovery rate of L. pneumophila ATCC® 33823 on the specific medium BCYE for the cultivation of Legionella, and BMPA, the selective medium. Methods: Suspension of L. pneumophila ATCC® 33823 of 0.5 McFarland was diluted to 10 fold serial dilution; 100 ul of each dilution was inoculated on Buffered Charcoal Yeast Extract (BCYE) medium, and BMPA (BCYE supplemented with BMPA-α) in duplicate manner. The concentration was calculated using Total Plate Count standard as of Indonesian Nasional Standard number 01-2332.3-2006. The percentage of recovery rate was calculated, and the statistical analysis was performed using SPSS version 23.0. Results: Numbers of colonies of L. pneumophila grew on BMPA was much higher than on BCYE medium; the highest concentration was yielded on BMPA medium i.e. 1.45x107 CFU/ml. The recovery rates were 96.67% and 60.67% on BMPA medium and BCYE subsequently. Conclusion: The recovery rate of the BMPA medium on the colony growth of L. pneumophila ATCC®33823 was markedly higher than the BCYE, therefore BMPA medium can be suggested to be used in the cultivation of L. pneumophila especially in the routine surveillance program for water sources with less cost. (Health Science Journal of Indonesia 2020;11(1):32-7)