Molecular characterization and toxigenic profiles of Bacillus cereus isolates from foodstuff and food poisoning outbreaks in Brazil

• Published in: Brazilian journal of microbiology 2024-06, Vol.55 (2), p.1693-1701
• Main Authors: dos Santos Mascarenhas, Luís Renato, Vivoni, Adriana Marcos, Caetano, Renata Gomes, Rusak, Leonardo Alves, Alvarenga, Verônica Ortiz, Lacerda, Inayara Cristina Alves
• Format: Article
• Language: English
• Subjects: Bacillus cereus - classification; Bacillus cereus - genetics; Bacillus cereus - isolation & purification; Bacillus cereus - pathogenicity; Biomedical and Life Sciences; Brazil - epidemiology; Disease Outbreaks; Enterotoxins - genetics; Food Microbiology; Food Microbiology - Research Paper; Foodborne Diseases - epidemiology; Foodborne Diseases - microbiology; Gram-Positive Bacterial Infections - epidemiology; Gram-Positive Bacterial Infections - microbiology; Humans; Life Sciences; Medical Microbiology; Microbial Ecology; Microbial Genetics and Genomics; Microbiology; Mycology; Virulence Factors - genetics
• ISSN: 1517-8382; 1678-4405; 1678-4405
• DOI: 10.1007/s42770-024-01283-4

Bacillus cereus sensu stricto ( s.s .) is a well-known foodborne pathogen that produces a range of enterotoxins and is able to cause two different types of foodborne illnesses—the emetic and the diarrheal syndromes. In this study, 54 B. cereus s.s. strains isolated from foodstuff and foods involved in food poisoning outbreaks were characterized according to the presence of toxin-encoding genes, virulence-encoding genes, and panC typing. Most isolates were assigned to panC groups IV (61.1%) and III (25.9%), but members of groups II and V could also be found. Investigation of specific alleles revealed high numbers of isolates carrying toxin and other virulence genes including nheA (100%), nheB (100%), hblA (79.6%), hblC (79.6%), hblD (74.1%), cytK-2 (61.1%), clo (100%), pc-plc (75.9%), sph (68.5%), pi-plc (66.6%), hlyIII (62.9%), and hlyII (24.1%). All isolates were negative for ces and cytK-1 . In summary, we detected various enterotoxin and other virulence factor genes associated with diarrheal syndrome in strains analyzed, implicated or not with food poisoning . Furthermore, the most isolates analyzed belong to high-risk phylogenetic groups’ panC types III and IV. Our study provides a convenient molecular scheme for characterization of B. cereus s.s. strains responsible for food poisoning outbreaks in order to improve the monitoring and investigation and assess emerging clusters and diversity of strains.