Currently, Salmonella enterica Typhimurium (ST) is responsible for most cases of food poisoning in several countries. It is characterized as a non-specific zoonotic bacterium that can infect both humans and animals and although most of the infections caused by this microorganism cause only a self-limiting gastroenteritis, some ST strains have been shown to be invasive, crossing the intestinal wall and reaching the systemic circulation. This unusual pathogenicity ability is closely related to ST virulence factors. This review aims to portray the main virulence factors in Salmonella Typhimurium, in order to better understand the strategies that this pathogen uses to reach the systemic circulation and increase its infectivity in humans and animals. Thus, the most studied Salmonella pathogenicity islands in Salmonella Typhimurium were detailed as to the functions of their encoded virulence factors. In addition, available knowledge on virulence plasmid was also compiled, as well as the chromosome regions involved in the virulence of this bacterium.

Rodrigues et al. AMR Salmonella From Brazil frequency rates of antimicrobial resistance genes and predicted resistance phenotypes in the 2000s and the 2010s when compared with the 1980s and 1990s. The results presented herein contributed significantly to the understanding of the strategic use of WGS associated with in silico analysis and the predictions for the determination of AMR in Salmonella from Brazil.

Campylobacter jejuni (C. jejuni) is responsible for 80% of human campylobacteriosis and is the leading cause of gastroenteritis globally. The relevant public health risks of C. jejuni are caused by particular virulence genes encompassing its virulome. We analyzed 40,371 publicly available genomes of C. jejuni deposited in the NCBI Pathogen Detection Database, combining their epidemiologic metadata with an in silico bioinformatics analysis to increase our current comprehension of their virulome from a global perspective. The collection presented a virulome composed of 126 identified virulence factors that were grouped in three clusters representing the accessory, the softcore, and the essential core genes according to their prevalence within the genomes. The multilocus sequence type distribution in the genomes was also investigated. An unexpected low prevalence of the full-length flagellin flaA and flaB locus of C. jejuni genomes was revealed, and an essential core virulence gene repertoire prevalent in more than 99.99% of genomes was identified. Altogether, this is a pioneer study regarding Campylobacter jejuni that has compiled a significant amount of data about the Multilocus Sequence Type and virulence factors concerning their global prevalence and distribution over this database.

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