The incidence of
Shigella
spp. was assessed in 877 infants from the public hospital in Rondônia (Western Amazon region, Brazil) where
Shigella represents the fourth cause of diarrhea. Twenty-five isolates were identified: 18 were
Shigella flexneri
, three
Shigella sonnei
, three
Shigella boydii
and one
Shigella dysenteriae
. With the exception of
S. dysenteriae, all
Shigella spp. isolated from children with diarrhea acquired multiple antibiotic resistances. PCR detection of ipa virulence genes and invasion assays of bloody diarrhea and fever (colitis) were compared among 25 patients testing positive for
Shigella. The
ipaH and
ipaBCD genes were detected in almost all isolates and, unsurprisingly, all
Shigella isolates associated with colitis were able to invade HeLa cells. This work alerts for multiple antibiotic resistant
Shigella in the region and characterizes presence of
ipa virulence genes and invasion phenotypesin dysenteric shigellosis.