Salmonella Typhimurium (ST313) has caused an epidemic of
invasive disease in sub-Saharan Africa and has been recently
identified in Brazil. As the virulence of this ST is poorly understood,
the present study aimed to (i) perform the RNAseq
in vitro of S. Typhimurium STm30 (ST313) grown in
Luria-Bertani medium at 37°C; (ii) compare it with the RNAseq
of the S. Typhimurium SL1344 (ST19) and S. Typhimurium
STm11 (ST19) strains under the same growing conditions;
and (iii) examine the colonization capacity and expression
of virulence genes and cytokines in murine colon. The
STm30 (ST313) strain exhibited stronger virulence and was
associated with a more inflammatory profile than the strains
SL1344 (ST19) and STm11 (ST19), as demonstrated by transcriptome
and in vivo assay. The expression levels of the hilA,
sopD2, pipB, and ssaS virulence genes, other Salmonella pathogenicity
islands SPI-1 and SPI-2 genes or effectors, and
genes of the cytokines IL-1β, IFN-γ, TNF-α, IL-6, IL-17, IL-22,
and IL-12 were increased during ST313 infection in C57BL/6J
mice. In conclusion, S. Typhimurium STm30 (ST313) isolated
from human feces in Brazil express higher levels of pathogenesis-
related genes at 37°C and has stronger colonization
and invasion capacity in murine colon due to its high expression
levels of virulence genes, when compared with the S.
Typhimurium SL1344 (ST19) and STm11 (ST19) strains.
STm30 (ST313) also induces stronger expression of pro-inflammatory
cytokines in this organ, suggesting that it causes
more extensive tissue damage.
Severe fever with thrombocytopenia syndrome (SFTS) is a
tick-borne emerging infectious disease caused by the SFTS
virus (SFTSV) and is a threat to public health due to its high
fatality rate. However, details on tick-to-human transmission
of SFTSV are limited. In this study, we determined the wholegenome
sequence of a South Korean SFTSV strain (CUKJJ01),
compared it to those of other recent human SFTSV
isolates, and identified the genetic variations and relationships
among the SFTSV strains. The genome of CUK-JJ01
was consistent with the genome of other members of the genus
Phlebovirus, including the large (L), medium (M), and
small (S) segments of 6368, 3378, and 1744 nucleotides, respectively.
Based on amino acid sequences of the M and S
segments, which are used to distinguish the six SFTSV genotypes,
CUK-JJ01 was classified as genotype B. Segment analysis
revealed that the L, M, and S segments were 97.49%,
97.18%, and 97.94% similar to those of KAJNH2/2013/
Korea, ZJZHSH-FDE/2012/China, and KADGH/2013/Korea,
respectively. Currently, only few studies on SFTSV have been
conducted in Korean population and most were limited to
serological analysis. Although the present study has limitations
in terms of number of sample analyzed, the findings
may serve as basis to understand the transmission and spread
of SFTSV, as well as for the development of diagnostic and
detection methods for viral recombinants by comparing
the whole genome sequence of SFTSV isolates from South
Korea and that of foreign isolates.