Carbapenem-resistant Acinetobacter baumannii in Brazil: susceptibility profile and diversity of oxacillinases

• Autor(a) principal: Rocha,Lisiane
• Data de Publicação: 2017
• Outros Autores: Pagano,Mariana, Campos,Juliana C., Sampaio,Jorge Luiz M., Martins,Andreza F., Barth,Afonso Luis
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Jornal Brasileiro de Patologia e Medicina Laboratorial (Online)
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1676-24442017000600358
• topic: Acinetobacter baumannii; carbapenems; beta-lactamases

ABSTRACT Introduction: The Acinetobacter calcoaceticus-baumannii (ABC) complex includes five species, and the A. baumannii is the most important of them because it carries mechanisms of carbapenems resistance, especially the oxacillinases. Objectives: The objectives of this study were to identify the species of the ABC complex, to evaluate the susceptibility profile and to investigate the presence of oxacillinases in carbapenems-resistant isolates from four Brazilian States. Methods: In the study period, 92 isolates from Rio Grande do Sul (RS), Rio de Janeiro (RJ), Paraná (PR) and São Paulo (SP) were collected. The isolates were identified by matrix-assisted laser desorption ionization-time of fight mass spectrometry (MALDI-TOF MS) and sequencing of gyrB gene. Evaluation of susceptibility was performed by disk diffusion and broth microdilution. The presence of oxacillinases was performed by in-house multiplex polymerase chain reaction (PCR). Results: Ninety-one (99%) isolates were identified as A. baumannii by MALDI-TOF and sequencing. The majority of isolates (56; 61%) showed resistance to the six antimicrobial agents tested. Three isolates were resistant to polymyxin B [minimum inhibitory concentration (MIC) ≥ 4 µg/ml). Eighty (87%) isolates were positive to OXA-23-like, and twelve (13%) isolates to OXA-24-like. Conclusion: Our findings confirm the knowledge about the dissemination of the blaOXA-23 gene in Brazil and suggest the recent emergence and spread of blaOXA-24 gene, since it was identified in three of the four sampled states.