Phylogenetic analysis of bacillus cereus sensu lato isolates from commercial bee pollen using tRNA^Cys-PCR

• Type of Material: Article
• Authors: Jose Luis Hernandez Flores, Centro de Investigacion y de Estudios Avanzados; Diana Salinas Landaverde, Universidad Autónoma de Querétaro; Yonuen Pacheco Huerta, Universidad Autónoma de Querétaro; Vania Lizeth Guerra Castillo, Universidad Autónoma de Querétaro; Maria de los Angeles Barrios Sánchez, Universidad Autónoma de Querétaro; Ivan Arvizu Hernández, Universidad Autónoma de Querétaro; Miguel Angel Ramos López, Universidad Autónoma de Querétaro; Erika Alvarez Hidalgo, Universidad Autónoma de Querétaro; George Jones, Emory University; Juan Campos Guillén, Universidad Autónoma de Querétaro
• Language: English
• Date: 2020-04-01
• Publisher: MDPI
• Publication Version: Final Published Version
• Copyright Statement: © 2020 by the authors. Licensee MDPI, Basel, Switzerland.
• License: Creative Commons Attribution 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.3390/microorganisms8040524
• Title of Journal or Parent Work: Microorganisms
• Volume: 8
• Issue: 4
• Grant/Funding Information: This study was partially financed by the Universidad Autónoma de Querétaro (FONDEC-UAQ-2019-FCQ202001 and FONDO “QUÍMICA SOMOS TODOS” 2019-Folio 17).
• Keywords: Phylogenetic analysis; Biomedical Engineering; Commercial bee pollen; Biochemistry; Genetic engineering
• Research Categories: Biology, Plant Physiology; Biology, Genetics; Engineering, Biomedical; Chemistry, Biochemistry

Abstract

Endospore-forming bacteria related to the Bacillus cereus group produce toxins that cause illnesses in organisms from invertebrates to mammals, including foodborne illnesses in humans. As commercial bee pollen can be contaminated with these bacteria, a comprehensive microbiological risk assessment of commercial bee pollen must be incorporated into the relevant regulatory requirements, including those that apply in Mexico. To facilitate detection of members of this group of bacteria, we have developed a PCR strategy that is based on the amplification of the single-copy tRNACys gene and specific genes associated with tRNACys to detect Bacillus cereus sensu lato (B. cereus s.l.). This tRNACys-PCR-based approach was used to examine commercial bee pollen for endospore-forming bacteria. Our analysis revealed that 3% of the endospore-forming colonies isolated from a commercial source of bee pollen were related to B. cereus s.l., and this result was corroborated by phylogenetic analysis, bacterial identification via MALDI-TOF MS, and detection of enterotoxin genes encoding the HBL and NHE complexes. The results show that the isolated colonies are closely related phylogenetically to B. cereus, B. thuringiensis, and B. bombysepticus. Our results indicate that the tRNACys-PCR, combined with other molecular tools, will be a useful approach for identifying B. cereus s.l. and will assist in controlling the spread of potential pathogens.