title: Colistin resistance in a clinical Acinetobacter baumannii strain appearing after colistin treatment: effect on virulence and bacterial fitness.
abstract: The fitness and virulence costs associated with the clinical acquisition of colistin resistance by Acinetobacter baumannii were evaluated. The growth of strain CR17 (colistin resistant) was less than that of strain CS01 (colistin susceptible) when the strains were grown in competition (72-h competition index, 0.008). In a murine sepsis model, CS01 and CR17 reached spleen concentrations when coinfecting of 9.31 and 6.97 log10 CFU/g, respectively, with an in vivo competition index of 0.016. Moreover, CS01 was more virulent than CR17 with respect to mortality and time to death.
authors.affiliation: Institute of Biomedicine of Seville (IBiS), University Hospital Virgen del Rocío/CSIC/University of Seville, Seville, Spain. rlopezrojas@hotmail.com
authors.forename: Rafael
authors.initials: R
authors.lastname: López-Rojas
authors.forename: Michael J
authors.initials: MJ
authors.lastname: McConnell
authors.forename: Manuel Enrique
authors.initials: ME
authors.lastname: Jiménez-Mejías
authors.forename: Juan
authors.initials: J
authors.lastname: Domínguez-Herrera
authors.forename: Felipe
authors.initials: F
authors.lastname: Fernández-Cuenca
authors.forename: Jerónimo
authors.initials: J
authors.lastname: Pachón
mesh_terms: D000151:Acinetobacter Infections / Q000188:drug therapy / Q000382:microbiology / Q000401:mortality / Q000662:veterinary*; D040981:Acinetobacter baumannii / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development / Q000472:pathogenicity; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D003091:Colistin / Q000494:pharmacology*; D015169:Colony Count, Microbial; D024881:Drug Resistance, Bacterial / Q000187:drug effects / Q000235:genetics; D005260:Female; D056084:Genetic Fitness / Q000187:drug effects*; D051379:Mice; D008810:Mice, Inbred C57BL; D008826:Microbial Sensitivity Tests; D018805:Sepsis / Q000188:drug therapy / Q000382:microbiology / Q000401:mortality / Q000662:veterinary*; D016019:Survival Analysis; D014774:Virulence
chemical_list: D000900:Anti-Bacterial Agents; D003091:Colistin