title: Phenotypic changes in nonfimbriated smooth strains of Aggregatibacter actinomycetemcomitans grown in low-humidity solid medium.
abstract: Aggregatibacter actinomycetemcomitans is the primary etiologic agent of localized aggressive periodontitis. In vitro, it can undergo fimbriated rough to nonfimbriated smooth phenotypic transition, accompanied by an increase in invasive ability and a decrease in adhesive ability. No opposite direction phenotypic transition was reported. To better understand its pathogenicity, the authors studied the morphological changes of nonfimbriated smooth strains induced by growth environmental humidity. Transmission electron microscopy was used to identify fimbriae expression change. It was found that the lower medium humidity, the more fimbriae reexpressed. In conclusion, the smooth strain of A. actinomycetemcomitans can reexpress the fimbriae in lower humidity environment.
authors.affiliation: Department of Stomatology, The 306th Hospital of PLA, Beijing, China.
authors.forename: Zhenhua
authors.initials: Z
authors.lastname: Pei
authors.forename: Zhongying
authors.initials: Z
authors.lastname: Niu
authors.forename: Shenggen
authors.initials: S
authors.lastname: Shi
authors.forename: Liang
authors.initials: L
authors.lastname: Shi
authors.forename: Chuhua
authors.initials: C
authors.lastname: Tang
mesh_terms: D016976:Aggregatibacter actinomycetemcomitans / Q000235:genetics / Q000254:growth & development / Q000648:ultrastructure*; D003470:Culture Media; D005098:Exotoxins / Q000235:genetics; D010861:Fimbriae, Bacterial / Q000648:ultrastructure*; D006801:Humans; D006813:Humidity; D046529:Microscopy, Electron, Transmission; D010518:Periodontitis / Q000175:diagnosis / Q000382:microbiology; D010641:Phenotype; D016133:Polymerase Chain Reaction; D012329:RNA, Bacterial / Q000235:genetics
chemical_list: D003470:Culture Media; D005098:Exotoxins; D012329:RNA, Bacterial; C018579:leukotoxin