Role of the sseK1 gene in the pathogenicity of Salmonella enterica serovar enteritidis in vitro and in vivo.

Salmonella enteritidis is a common food-borne pathogen associated with consumption of contaminated poultry meat and eggs, which frequently causes gastroenteritis in humans. Salmonella secreted effector K1 (SseK1), as a translocated and secreted protein has been identified to be essential for the virulence of Salmonella typhimurium in host cells. However, the role of the sseK1 gene in the pathogenicity of S. enteritidis remain unclear. In this study, a sseK1 deletion mutant of S. enteritidis was constructed and its biological characteristics were examined. It was found that the sseK1 deletion mutant did not affect the growth, adherence and invasion of Salmonella enteritidis when compared to the wild-type S. enteritidis. However, the mutant showed decreased formation of biofilm and significantly reduced intracellular survival of bacteria in activated mouse peritoneal macrophages, as well as showed reduced pathogenicity to a murine model by increasing the lethal dose 50% (LD50) value and decreasing the proliferation ratio of bacteria in vivo. Taken together, this study determined an important role for SseK1 in the pathogenicity of S. enteritidis in vitro and in vivo.

Yang Y ，Yu C ，Ding K ，Zhang C ，Liao C ，Jia Y ，Li J ，Cheng X ... -  《-》

Cell invasion of poultry-associated Salmonella enterica serovar Enteritidis isolates is associated with pathogenicity, motility and proteins secreted by the type III secretion system.

Shah DH ，Zhou X ，Addwebi T ，Davis MA ，Orfe L ，Call DR ，Guard J ，Besser TE ... -  《-》

Roles of the spiA gene from Salmonella enteritidis in biofilm formation and virulence.

Dong H ，Peng D ，Jiao X ，Zhang X ，Geng S ，Liu X ... -  《-》

Biofilm formation by Salmonella Enteritidis and Salmonella Typhimurium isolated from avian sources is partially related with their in vivo pathogenicity.

Salmonella Enteritidis and Salmonella Typhimurium are among the most prevalent serotypes isolated from salmonellosis outbreaks and poultry. Salmonella spp. have the capacity to form biofilms on several surfaces, which can favour survival in hostile environments, such as slaughterhouses. Salmonella strains present differences in pathogenicity. However, there is little information regarding the pathogenicity of S. Enteritidis and S. Typhimurium isolated from avian sources and their relationship to biofilm production. The aim of this study was to use a novel pathogenicity index and a biofilm production assay to evaluate their relationships within these serotypes. In addition, we detected the presence of the spiA and agfA genes in these strains. Biofilm formation was investigated at two temperatures (37 °C and 28 °C) using microtiter plate assay, and the results were compared with the individual pathogenicity index of each strain. PCR was used to detect spiA and agfA, virulence genes associated with biofilm production. S. Enteritidis and S. Typhimurium strains were capable of producing biofilm at 37 °C and 28 °C. Sixty-two percent and 59.5% of S. Enteritidis and 73.8% and 46.2% of S. Typhimurium produced biofilm at 37 °C and 28 °C, respectively. Biofilm production at 37 °C was significantly higher in both serotypes. Only S. Enteritidis was capable of adhering strongly at both temperatures. Biofilm production was related to pathogenicity index only at 28 °C for S. Enteritidis. spiA and agfA were found in almost all strains and were not statistically associated with biofilm production.

Borges KA ，Furian TQ ，de Souza SN ，Menezes R ，de Lima DA ，Fortes FBB ，Salle CTP ，Moraes HLS ，Nascimento VP ... -  《-》

SseK1 and SseK2 are novel translocated proteins of Salmonella enterica serovar typhimurium.

Kujat Choy SL ，Boyle EC ，Gal-Mor O ，Goode DL ，Valdez Y ，Vallance BA ，Finlay BB ... -  《-》