title: Trends in the resistance profiles of Acinetobacter baumannii endemic clones in a university hospital of Argentina.
abstract: A total of 925 Acinetobacter spp. isolates were collected from routine clinical samples of patients admitted to the university hospital of Buenos Aires city during the period 2004-2012. From this collection, 129 isolates identified as Acinetobacter baumannii were selected for molecular studies. Minimal inhibitory concentrations (MICs) of antimicrobials were determined by agar dilution method. Colistin (COL) heteroresistance was investigated by means of population analysis studies. PCR-based methods were used for epidemiological analysis and for the screening of carbapenemases and the bla(tetB) gene. We have observed a steady rise in the MIC50 of imipenem (IMI)-resistant isolates and an increment in the presence of bla(OXA-23)-like gene (74-100%) as well. A rapid increasing rate of minocycline (MIN) resistance and a rise of the MIC50 of the resistant isolates have been detected since the year 2008. All isolates harboured the tet (B) gene. An increase in the value of the tigecycline (TIG) MIC was seen from the year 2007 onwards. This loss of activity was observed among different clones. A rise of COL heteroresistance from 46.4% in 2004 to 95% in 2012 was detected. During this period, COL consumption also increased (11.1-fold). However, COL resistance remained sporadic.
authors.affiliation: a Laboratorio de Bacteriología, Departamento de Bioquímica Clínica, Hospital de Clínicas José de San Martín, Facultad de Farmacia y Bioquímica , Universidad de Buenos Aires , Buenos Aires , Argentina.
authors.forename: Carlos Hernan
authors.initials: CH
authors.lastname: Rodríguez
authors.affiliation: a Laboratorio de Bacteriología, Departamento de Bioquímica Clínica, Hospital de Clínicas José de San Martín, Facultad de Farmacia y Bioquímica , Universidad de Buenos Aires , Buenos Aires , Argentina.
authors.forename: Marcela
authors.initials: M
authors.lastname: Nastro
authors.affiliation: a Laboratorio de Bacteriología, Departamento de Bioquímica Clínica, Hospital de Clínicas José de San Martín, Facultad de Farmacia y Bioquímica , Universidad de Buenos Aires , Buenos Aires , Argentina.
authors.forename: Graciela
authors.initials: G
authors.lastname: Fiorilli
authors.affiliation: a Laboratorio de Bacteriología, Departamento de Bioquímica Clínica, Hospital de Clínicas José de San Martín, Facultad de Farmacia y Bioquímica , Universidad de Buenos Aires , Buenos Aires , Argentina.
authors.forename: Laura
authors.initials: L
authors.lastname: Dabos
authors.affiliation: b Servicio de Farmacia, Hospital de Clínicas José de San Martín , Universidad de Buenos Aires , Buenos Aires , Argentina.
authors.forename: Jimena
authors.initials: J
authors.lastname: Lopez Calvo
authors.affiliation: b Servicio de Farmacia, Hospital de Clínicas José de San Martín , Universidad de Buenos Aires , Buenos Aires , Argentina.
authors.forename: Maria Elisa
authors.initials: ME
authors.lastname: Fariña
authors.affiliation: a Laboratorio de Bacteriología, Departamento de Bioquímica Clínica, Hospital de Clínicas José de San Martín, Facultad de Farmacia y Bioquímica , Universidad de Buenos Aires , Buenos Aires , Argentina.
authors.forename: Carlos
authors.initials: C
authors.lastname: Vay
authors.affiliation: a Laboratorio de Bacteriología, Departamento de Bioquímica Clínica, Hospital de Clínicas José de San Martín, Facultad de Farmacia y Bioquímica , Universidad de Buenos Aires , Buenos Aires , Argentina.
authors.forename: Angela
authors.initials: A
authors.lastname: Famiglietti
mesh_terms: D000151:Acinetobacter Infections / Q000188:drug therapy / Q000453:epidemiology* / Q000382:microbiology*; D040981:Acinetobacter baumannii / Q000187:drug effects* / Q000302:isolation & purification; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001118:Argentina / Q000453:epidemiology; D024901:Drug Resistance, Multiple, Bacterial; D019353:Endemic Diseases; D006785:Hospitals, University; D006801:Humans; D008826:Microbial Sensitivity Tests
chemical_list: D000900:Anti-Bacterial Agents
keywords: Acinetobacter baumannii; Colistin heteroresistance; Colistin resistance; Colistin usage; OXA-23; tet (B)