Bacteriophage amplification assay for detection of Listeria spp. using virucidal laser treatment

Revista de microbiologia

Hofer, E.¹  Oliveira, I.C.²  Almeida, R.C.C.³ 

[1] Instituto Oswaldo Cruz, Rio de Janeiro, Brasil;Universidade Estadual da Bahia, Salvador, Brasil;Universidade Federal da Bahia, Salvador, Brasil

关键词: Listeria;    bacteriophage A511;    laser light;    detection;    skimmed milk.;   

DOI  :  10.1590/S1517-83822012000300040

学科分类：农业科学（综合）

来源: Sociedade Brasileira de Microbiologia / Brazilian Society for Microbiology

【 摘 要 】

A protocol for the bacteriophage amplification technique was developed for quantitative detection of viable Listeria monocytogenes cells using the A511 listeriophage with plaque formation as the end-point assay. Laser and toluidine blue O (TBO) were employed as selective virucidal treatment for destruction of exogenous bacteriophage. Laser and TBO can bring a total reduction in titer phage (ca. 108 pfu/mL) without affecting the viability of L. monocytogenes cells.  Artificially inoculated skimmed milk revealed mean populations of the bacteria as low as between 13 cfu/mL (1.11 log cfu/mL), after a 10-h assay duration. Virucidal laser treatment demonstrated better protection of Listeria cells than the other agents previously tested. The protocol was faster and easier to perform than standard procedures. This protocol constitutes an alternative for rapid, sensitive and quantitative detection of L. monocytogenes.

【 授权许可】

CC BY-NC