title: Epidemiologic and clinical impact of Acinetobacter baumannii colonization and infection: a reappraisal.
abstract: Acinetobacter baumannii is one of the most important antibiotic-resistant nosocomial bacteria. We investigated changes in the clinical and molecular epidemiology of A. baumannii over a 10-year period. We compared the data from 2 prospective multicenter cohort studies in Spain, one performed in 2000 (183 patients) and one in 2010 (246 patients), which included consecutive patients infected or colonized by A. baumannii. Molecular typing was performed by repetitive extragenic palindromic polymerase chain reaction (REP-PCR), pulsed-field gel electrophoresis (PFGE), and multilocus sequence typing (MLST). The incidence density of A. baumannii colonization or infection increased significantly from 0.14 in 2000 to 0.52 in 2010 in medical services (p < 0.001). The number of non-nosocomial health care-associated cases increased from 1.2% to 14.2%, respectively (p < 0.001). Previous exposure to carbapenems increased in 2010 (16.9% in 2000 vs 27.3% in 2010, p = 0.03). The drugs most frequently used for definitive treatment of patients with infections were carbapenems in 2000 (45%) and colistin in 2010 (50.3%). There was molecular-typing evidence of an increase in the frequency of A. baumannii acquisition in non-intensive care unit wards in 2010 (7.6% in 2000 vs 19.2% in 2010, p = 0.01). By MSLT, the ST2 clonal group predominated and increased in 2010. This epidemic clonal group was more frequently resistant to imipenem and was associated with an increased risk of sepsis, although not with severe sepsis or mortality. Some significant changes were noted in the epidemiology of A. baumannii, which is increasingly affecting patients admitted to conventional wards and is also the cause of non-nosocomial health care-associated infections. Epidemic clones seem to combine antimicrobial resistance and the ability to spread, while maintaining their clinical virulence.
authors.affiliation: Unidad Clínica de Enfermedades Infecciosas y Microbiología (MV, FFC, AP, JRB), Hospital Universitario Virgen Macarena, Seville; Servicio de Microbiología (MEC, CRDA, LMM), Hospital Universitario Marqués de Valdecilla - IFIMAV, Santander; Servicio de Microbiología (EG, MT, GB), Complejo Hospitalario Universitario A Coruña, A Coruña; Unidad Clínica de Cuidados Críticos y Urgencias Hospital Universitario Virgen del Rocío (JGM), Seville; Unidad de Enfermedades Infecciosas (JMC), Microbiología y Medicina Preventiva, Hospital Universitario Virgen del Rocío - Instituto de Biomedicina de Sevilla (IBIS), Seville; Departamento de Biología Molecular (LMM), Universidad de Cantabria, Santander; Hospital Clinic (JV), Barcelona; Departamento de Microbiología (AP) and Departamento de Medicina (JRB), Universidad de Sevilla, Seville; Spain. Other participants from the GEIH/GEMARA/REIPI-Ab2010 Group are listed in the Appendix.
authors.forename: Macarena
authors.initials: M
authors.lastname: Villar
authors.forename: María E
authors.initials: ME
authors.lastname: Cano
authors.forename: Eva
authors.initials: E
authors.lastname: Gato
authors.forename: José
authors.initials: J
authors.lastname: Garnacho-Montero
authors.forename: José
authors.initials: J
authors.lastname: Miguel Cisneros
authors.forename: Carlos
authors.initials: C
authors.lastname: Ruíz de Alegría
authors.forename: Felipe
authors.initials: F
authors.lastname: Fernández-Cuenca
authors.forename: Luis
authors.initials: L
authors.lastname: Martínez-Martínez
authors.forename: Jordi
authors.initials: J
authors.lastname: Vila
authors.forename: Alvaro
authors.initials: A
authors.lastname: Pascual
authors.forename: María
authors.initials: M
authors.lastname: Tomás
authors.forename: Germán
authors.initials: G
authors.lastname: Bou
authors.forename: Jesús
authors.initials: J
authors.lastname: Rodríguez-Baño
mesh_terms: D000151:Acinetobacter Infections / Q000175:diagnosis / Q000188:drug therapy / Q000453:epidemiology / Q000503:physiopathology; D040981:Acinetobacter baumannii / Q000145:classification / Q000187:drug effects / Q000302:isolation & purification / Q000472:pathogenicity; D000368:Aged; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D015373:Bacterial Typing Techniques; D015780:Carbapenems / Q000494:pharmacology*; D015331:Cohort Studies; D003091:Colistin / Q000494:pharmacology*; D015169:Colony Count, Microbial / Q000379:methods; D003428:Cross Infection / Q000175:diagnosis / Q000188:drug therapy / Q000453:epidemiology / Q000382:microbiology / Q000503:physiopathology; D024881:Drug Resistance, Bacterial; D016521:Electrophoresis, Gel, Pulsed-Field / Q000379:methods; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D013030:Spain / Q000453:epidemiology
chemical_list: D000900:Anti-Bacterial Agents; D015780:Carbapenems; D003091:Colistin