In vitro and in vivo assessment of Salmonella enterica serovar typhimuriumDT104 virulence

Multidrug-resistant Salmonella enterica serovar Typhimurium phage type DT10 4 has become a widespread cause of human and ether animal infection worldwi de. The severity of clinical illness in S, enterica serovar Typhimurium DT1 04 outbreaks has led to the suggestion that this strain possesses enhanced virulence, In the present study, in vitro and in vivo virulence-associated phenotypes of several clinical isolates of S. enterica serovar Typhimurium DT104 were examined and compared to S. enterica serovar Typhimurium ATCC 14 028s. The ability of these DT104 isolates to survive within murine peritone al macrophages, invade cultured epithelial cells, resist antimicrobial acti ons of reactive oxygen and nitrogen compounds, and cause lethal infection i n mice were assessed. Our results failed to demonstrate that S. enterica se rovar Typhimurium DT104 isolates are more virulent than S, enterica serovar Typhimurium ATCC 14028s.