title: [Evaluation of direct susceptibility testing from blood culture bottles. Clinical usefulness].
abstract: A prospective observational study was conducted in two hospitals of Buenos Aires city (Argentina); 191 clinically significant monomicrobial gram-negative bloodstream infections were included in the study, which combined the Bact-Alert System Blood culture machine and the Vitek 2C System. Organism identification and susceptibility results directly from blood culture bottles were compared with those obtained from cards inoculated with a standardized bacterial suspension obtained following subculture on agar. By comparing the results obtained from pure cultures with those by the Vitek 2C System as reference method, the agreement between the reference method and the direct identification from positive blood cultures was 99 %. By antimicrobial susceptibility testing, the overall categorical accuracy was 99 % (0.22 %, very major errors, 0.17 %, major errors and 0.61 %, minor errors). One hundred and eight (56,8 %) bloodstream infections were treated empirically with adequate antibiotics. After the results obtained directly from the bottles were reported, antimicrobial therapy was changed in 116 (60.7 %) of the episodes.
authors.affiliation: Laboratorio de Microbiología del Hospital Naval Pedro Mallo, Patricias Argentinas 351 (1405) Ciudad Autónoma de Buenos Aires, Argentina. rnsoloaga@yahoo.com
authors.forename: Rolando N
authors.initials: RN
authors.lastname: Soloaga
authors.forename: Natalia A
authors.initials: NA
authors.lastname: Carrion
authors.forename: Alejandra M
authors.initials: AM
authors.lastname: Margari
authors.forename: Marta
authors.initials: M
authors.lastname: Giovanakis
authors.forename: Alicia
authors.initials: A
authors.lastname: Sujemecki
authors.forename: Ernesto
authors.initials: E
authors.lastname: Efron
authors.forename: Juan C
authors.initials: JC
authors.lastname: Pidone
authors.forename: Liliana I
authors.initials: LI
authors.lastname: Guelfand
authors.forename: Mariela
authors.initials: M
authors.lastname: Mendez Aranibar
mesh_terms: D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D001118:Argentina; D016470:Bacteremia / Q000097:blood / Q000188:drug therapy / Q000382:microbiology; D001431:Bacteriological Techniques / Q000295:instrumentation*; D001769:Blood / Q000382:microbiology*; D003428:Cross Infection / Q000097:blood / Q000188:drug therapy / Q000382:microbiology; D006801:Humans; D008826:Microbial Sensitivity Tests / Q000295:instrumentation / Q000379:methods*; D011446:Prospective Studies; D012015:Reference Standards; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D000900:Anti-Bacterial Agents