The Proteomics Of Salmonella Serotype Paratyphi A Under Heat Stress

Salmonella serotype paratyphi A is a kind of non capsule produce spores,gram negative bacilli,and it could cause acute infectious disease of digestive tract.Salmonella serotype Paratyphi A are restricted to humans,especially children and young men.The paratyphoid A is perennial sporadic,most in summer and Autumn in China.Due to the influence of the medium and the heat adaptation of the Salmonella,Salmonella serotype paratyphi A,which still exists in the food,is a threat to food safety.The differential protein of Salmonella serotype paratyphi A has a very important role in heat stimulation.It is needed to study the mechanism of the heat resistance of Salmonella serotype paratyphi A to regulate and control Salmonella serotype paratyphi A by the method of proteomics.?1?In order to study the thermal inactivation regularity of Salmonella serotype paratyphi A in different medium.The vaccinated 107 cfu/g Salmonella serotype paratyphi A were added in different medium,then subjected to thermal treatment.The surviving cell number was counted on selective media.Dose Resp model was used to fit the thermal inactivation curve by Curve Expert software.The D values represented the heat resistance of Salmonella serotype paratyphi A The results showed that Salmonella serotype paratyphi A were killed for 25.0min at 55?,2.03 min at 63?,0.31 min at 72?.The curves fitted by Dose Resp model was well,it showed a high correlation at two temperature in the ready-to-eat meat?R2> 0.91?.The D values of Salmonella serotype paratyphi A in different mediumwere different.Salmonella serotype paratyphi A had a more heat resistant in the medium with high protein and fat content.?2?Different media were heat treated at 55?.And then the proteins were extracted from the treated samples.The proteins were identified by isobaric tags for relative and absolute quantitation?iTRAQ?combined with LC-MS/MS technology.The results were analyzed and quantified by using the software Mascot 2.2 and Proteome Discoverer1.4?thermo?.189 differentially expressed proteins were identified,and GO annotation,GO enrichment analysis and Pathway metabolic pathway annotation analysis.The results showed that the DNA cleavage enzyme?ligB?,DNA protective protein?DPS?,molecular chaperone?Hde B?,and some unknown functions of ACN89₂0515 and yna F proteins were adapted to the stress environment in the medium which fat was equal to lean compared to the medium of pure lean meat.?3?The whole bacterial protein was extracted by heat stress and normal temperature in the medium of pure lean meat.The proteins were identified by isobaric tags for relative and absolute quantitation?iTRAQ?combined with LC-MS/MS technology.The results were analyzed and quantified by using the software Mascot 2.2 and Proteome Discoverer1.4?thermo?.205 differentially expressed proteins were identified,and GO annotation,GO enrichment analysis and Pathway metabolic pathway annotation analysis.The results showed that molecular chaperone?HdeB?,possible transport protein?ygiW?,stress protein?DPS?,reaction control protein?copR? and unknown function of ACN89₂0515 proteins were adapted to the heat stress environment in the medium of pure lean meat.?4?The whole bacterial protein was extracted by heat stress and normal temperature in the medium which fat was equal to lean.The proteins were identified by isobaric tags for relative and absolute quantitation?iTRAQ?combined with LC-MS/MS technology.The results were analyzed and quantified by using the software Mascot 2.2 and Proteome Discoverer1.4?thermo?.108 differentially expressed proteins were identified,and GO annotation,GO enrichment analysis and Pathway metabolic pathway annotation analysis.The results showed that the putative outside pump protein?acrD?,chemotaxis protein?Tsr and cheA?,flagellar motility protein?fliG?,DNA binding protein?Fis?,movement protein?Mota?,reaction regulatory protein?CopR?,the cytoplasmic trehalase?treF?and DNA transfer enzyme?dam?were adapted to the heat stress environment in the medium which fat was equal to lean.