Isolation and identification of a pathogenic strain of Bacillus cereus from bovine and establishment of a rapid detection method for RPA-LF

Abstract

In order to identify the cause of death of a cattle that suddenly died on a cattle farm in Tongliao City, Inner Mongolia Autonomous Region, we isolated a strain of bacteria from the spleen and identified the pathogen. The study demonstrated that the isolated strain is Bacillus cereus. The isolates were highly pathogenic and contained toxin genes, such as hbl, nhe, and entFM, in addition to the groEL housekeeping gene. The isolated strain has been named TL strain (16S rDNA sequence number: OP028902, whole genome sequence number: CP129005). Isolates were deposited at China General Microbiological Culture Collection Center (CGMCC No.17626). In this study, we also developed a rapid recombinase polymerase amplification-based lateral flow (RPA-LF) for pathogenic Bacillus cereus. The virulence gene (nhe gene) was used as the target sequence to design RPA-LF assay primers and probes. The RPA reaction is fast (results can be observed in about 15 min), the results can be judged by the naked eye, and the specificity of the RPA-LF method is good. The RPA-LF method detects pathogenic Bacillus cereus in food, which reduces the risk of harm to human health. The RPA-LF assay provides a reference for the rapid detection of pathogenic Bacillus cereus.