EFS and infection: The cas3 deletion strain Δcas3 and complementary strain Δcas3/pBAD33-CM-cas3 were constructed to study the role of the cas3 gene in virulence regulation of Salmonella by detecting some important virulence phenotypes (e.g., biofilm formation, cell infection) and screening the key virulence genes that may be impacted by cas3 via RNA-Seq analysis.