Resistance Markers and Genetic Diversity in Acinetobacter baumannii Strains Recovered from Nosocomial Bloodstream Infections

International Journal of Environmental Research and Public Health

Hanoch S. I. Martins¹  Maria Rosa Q. Bomfim¹  Rafaela O. Fran๺¹  Luiz M. Farias¹  Maria Auxiliadora R. Carvalho¹  José Carlos Serufo² 

[1] Departamento de Microbiologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Antônio Carlos 6627, Pampulha 31207-901, Belo Horizonte, Minas Gerais, Brazil; E-Mails:;Departamento de Clínica Médica, Faculdade de Medicina, Universidade Federal de Minas Gerais, Professor Alfredo Balena 190, Santa Efigênia 30130-100, Belo Horizonte, MG, Brazil; E-Mail:

关键词: Acinetobacter baumannii;    bloodstream infections;    genetic diversity;    resistance markers;   

DOI  :  10.3390/ijerph110201465

来源: mdpi

【 摘 要 】

In this study, phenotypic and genotypic methods were used to detect metallo-β-lactamases, cephalosporinases and oxacillinases and to assess genetic diversity among 64 multiresistant Acinetobacter baumannii strains recovered from blood cultures in five different hospitals in Brazil from December 2008 to June 2009. High rates of resistance to imipenem (93.75%) and polymyxin B (39.06%) were observed using the disk diffusion (DD) method and by determining the minimum inhibitory concentration (MIC). Using the disk approximation method, thirty-nine strains (60.9%) were phenotypically positive for class D enzymes, and 51 strains (79.6%) were positive for cephalosporinase (AmpC). Using the E-test, 60 strains (93.75%) were positive for metallo-β-lactamases (MβLs). All strains were positive for at least one of the 10 studied genes; 59 (92.1%) contained bla_VIM-1, 79.6% contained bla_AmpC, 93.7% contained bla_OXA23 and 84.3% contained bla_OXA51. Enterobacteria Repetitive Intergenic Consensus (ERIC)-PCR analysis revealed a predominance of certain clones that differed from each other. However, the same band pattern was observed in samples from the different hospitals studied, demonstrating correlation between the genotypic and phenotypic results. Thus, ERIC-PCR is an appropriate method for rapidly clustering genetically related isolates. These results suggest that defined clonal clusters are circulating within the studied hospitals. These results also show that the prevalence of MDR A. baumannii may vary among clones disseminated in specific hospitals, and they emphasize the importance of adhering to appropriate infection control measures.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.