title: Interaction of Acinetobacter baumannii 19606 and 1656-2 with Acanthamoeba castellanii.
abstract: Acinetobacter baumannii is virtually avirulent for healthy people but maintains a high virulence among critically ill patients or immuno-compromised individuals. The ability of A. baumannii to adhere to cells and persist on surfaces as biofilms could be central to its pathogenicity. In the present study, we compared the virulence of the A. baumannii 1656-2 clinical strain, which is able to form a thick biofilm, with the virulence of the A. baumannii type strain (ATCC 19606(T)). Acanthamoeba castellanii, a single-celled organism, was used as the host model system to study the virulence of A. baumannii. Compared to A. baumannii ATCC 19606(T), A. baumannii 1656-2 exhibited a higher ability to adhere and invade A. castellanii cells and had a higher killing rate of A. castellanii cells. Furthermore, co-incubation of the amoeba cells and the cell-free supernatant of A. baumannii resulted in the cell death of the amoebae. Heat inactivation or proteinase K treatment of the supernatant did not eliminate its cytotoxicity, suggesting heat stable non-protein factors are responsible for its cytotoxicity to A. castellanii cells. In conclusion, this study for the first time has revealed the capacity of the A. baumannii strain and/or its metabolic products to induce cytotoxicity in A. castellanii cells.
authors: Department of Microbiology, Kyungpook National University School of Medicine, Daegu, 700-422, Republic of Korea.
authors: Migma Dorji
authors: MD
authors: Tamang
authors: Shukho
authors: S
authors: Kim
authors: Sung-Min
authors: SM
authors: Kim
authors: Hyun-Hee
authors: HH
authors: Kong
authors: Jungmin
authors: J
authors: Kim
mesh_terms: D048248:Acanthamoeba castellanii / Q000382:microbiology* / Q000502:physiology*; D040981:Acinetobacter baumannii / Q000254:growth & development / Q000472:pathogenicity / Q000502:physiology*; D001422:Bacterial Adhesion; D001427:Bacterial Toxins / Q000032:analysis / Q000633:toxicity; D016923:Cell Death; D002470:Cell Survival; D003470:Culture Media / Q000737:chemistry; D006801:Humans; D056265:Microbial Interactions
chemical_list: D001427:Bacterial Toxins; D003470:Culture Media