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

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.

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Bibliographic Details
Main Authors: Rocha,Lisiane, Pagano,Mariana, Campos,Juliana C., Sampaio,Jorge Luiz M., Martins,Andreza F., Barth,Afonso Luis
Format: Digital revista
Language:English
Published: Sociedade Brasileira de Patologia Clínica 2017
Online Access:http://old.scielo.br/scielo.php?script=sci_arttext&pid=S1676-24442017000600358
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