title: Impaired virulence and in vivo fitness of colistin-resistant Acinetobacter baumannii.
abstract: Acinetobacter baumannii (American Type Culture Collection strain 19606) acquires mutations in the pmrB gene during the in vitro development of resistance to colistin. The colistin-resistant strain has lower affinity for colistin, reduced in vivo fitness (competition index, .016), and decreased virulence, both in terms of mortality (0% lethal dose, 6.9 vs 4.9 log colony-forming units) and survival in a mouse model of peritoneal sepsis. These results may explain the low incidence and dissemination of colistin resistance in A. baumannii in clinical settings.
authors.affiliation: Servicio de Enfermedades Infecciosas, Instituto de Biomedicina de Sevilla, Hospital Universitario Virgen del Rocío/Consejo Superior de Investigaciones Científicas/Universidad de Seville, Sevilla, Spain. rlopezrojas@hotmail.com
authors.forename: Rafael
authors.initials: R
authors.lastname: López-Rojas
authors.forename: Juan
authors.initials: J
authors.lastname: Domínguez-Herrera
authors.forename: Michael J
authors.initials: MJ
authors.lastname: McConnell
authors.forename: Fernando
authors.initials: F
authors.lastname: Docobo-Peréz
authors.forename: Younes
authors.initials: Y
authors.lastname: Smani
authors.forename: María
authors.initials: M
authors.lastname: Fernández-Reyes
authors.forename: Luis
authors.initials: L
authors.lastname: Rivas
authors.forename: Jerónimo
authors.initials: J
authors.lastname: Pachón
mesh_terms: D000151:Acinetobacter Infections / Q000382:microbiology* / Q000401:mortality; D040981:Acinetobacter baumannii / Q000187:drug effects* / Q000472:pathogenicity*; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics; D003091:Colistin / Q000494:pharmacology*; D004195:Disease Models, Animal; D024881:Drug Resistance, Bacterial; D005260:Female; D051379:Mice; D008810:Mice, Inbred C57BL; D009154:Mutation; D010538:Peritonitis / Q000382:microbiology / Q000401:mortality; D018805:Sepsis / Q000382:microbiology / Q000401:mortality; D016019:Survival Analysis; D014157:Transcription Factors / Q000235:genetics; D014774:Virulence
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; C409039:PmrB protein, bacteria; D014157:Transcription Factors; D003091:Colistin