Comparative genome analysis of pathogenic and apathogenic strains of Carnobacterium maltaromaticum

Abstract

Carnobacterium maltaromaticum is a diverse lactic acid bacteria (LAB) that is found and isolated from various environments and habitats. It is present in a variety of foods that includes dairy as well as non-dairy products such as meat and fish where they are capable of producing flavors in milk and effective bacteriocins against Listeria monocytogenes in processed-food products, respectively. Apart from technological potential in food products, C. maltaromaticum is a known pathogen in fish and due to this reason, they are not considered safe by EFSA. This study aims to differentiate between genomes of fish pathogenic strains and non-pathogenic food strains of C. maltaromaticum. Therefore, to study the genomic differences in this diversely found specie, the phylogenetic & pan-core genome analysis, as well as safety assessment on the basis of virulence factors, antibiotic resistance and pathogenicity island acquisition was determined using in silico approach. Results show that increase in pseudogenes of SK series of pathogenic strains suggests the transition of pathogenic strains to host-adapted (fish) lifestyle. Moreover, the safety assessment revealed that apathogenic strains cannot be termed completely safe due to the presence of virulence factors and pathogenicity islands and thus, safety might be a strain-specific feature. The genomic variations and safety determined in this study will provide insight into the potential application of dairy strains as probiotics. However, further in-vivo evaluations are required to confirm their potential and safety