title: Deletion of the aceE gene (encoding a component of pyruvate dehydrogenase) attenuates Salmonella enterica serovar Enteritidis.
abstract: Salmonella enterica serovar Enteritidis (S. Enteritidis) is a major food-borne pathogen. From a transposon insertion mutant library created previously using S. Enteritidis 10/02, one of the mutants was identified to have a 50% lethal dose (LD(50) ) at least 100 times that of the parental strain in young chicks, with an attenuation in a poorly studied gene encoding a component of pyruvate dehydrogenase, namely the aceE gene. Evaluation of the in vitro virulence characteristics of the ΔaceE∷kan mutant revealed that it was less able to invade epithelial cells, less resistant to reactive oxygen intermediate, less able to survive within a chicken macrophage cell line and had a retarded growth rate compared with the parental strain. Young chicks vaccinated with 2 × 10(9) CFU of the ΔaceE∷kan mutant were protected from the subsequent challenge of the parental strain, with the mutant colonized in the liver and spleen in a shorter time than the group infected with the parental strain. In addition, compared with the parental strain, the ΔaceE∷kan mutant did not cause persistent eggshell contamination of vaccinated hens.
authors.affiliation: Animal Health Biotechnology Group, Temasek Life Sciences Laboratory, National University of Singapore, Singapore.
authors.forename: Ervinna
authors.initials: E
authors.lastname: Pang
authors.forename: Chang
authors.initials: C
authors.lastname: Tien-Lin
authors.forename: Madhan
authors.initials: M
authors.lastname: Selvaraj
authors.forename: Jason
authors.initials: J
authors.lastname: Chang
authors.forename: Jimmy
authors.initials: J
authors.lastname: Kwang
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D000900:Anti-Bacterial Agents / Q000633:toxicity; D002478:Cells, Cultured; D002645:Chickens; D004251:DNA Transposable Elements; D004847:Epithelial Cells / Q000382:microbiology; D017353:Gene Deletion; D007928:Lethal Dose 50; D008099:Liver / Q000382:microbiology; D008264:Macrophages / Q000382:microbiology; D050296:Microbial Viability / Q000187:drug effects; D016254:Mutagenesis, Insertional; D011768:Pyruvate Dehydrogenase Complex / Q000235:genetics* / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000633:toxicity; D012477:Salmonella enteritidis / Q000187:drug effects / Q000201:enzymology* / Q000254:growth & development / Q000472:pathogenicity*; D013154:Spleen / Q000382:microbiology; D016019:Survival Analysis; D037521:Virulence Factors / Q000235:genetics* / Q000378:metabolism*
chemical_list: D000900:Anti-Bacterial Agents; D004251:DNA Transposable Elements; D011768:Pyruvate Dehydrogenase Complex; D017382:Reactive Oxygen Species; D037521:Virulence Factors