Clinical and microbiological characteristics of OXA-23- and OXA-143-producing Acinetobacter baumannii in ICU patients at a teaching hospital, Brazil

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• 作者：Francelli Cordeiro Neves^a ; ^b ; ^{francellineves@gmail.com" class="auth_mail" title="E-mail the corresponding author} ; Wanessa T. Clemente^a ; ^b ; Nilton Lincopan^c ; ^d ; Isabela D. Paiã ; o^c ; Patrí ; cia R. Neves^c ; Roberta M. Romanelli^a ; ^b ; Stella S.S. Lima^a ; Luciene F. Paiva^a ; Paulo Henrique O. Mourã ; o^a ; Vandack A. Nobre-Junior^e
• 关键词：Acinetobacter baumannii ; Carbapenem resistance ; blaOXA-23 ; blaOXA-143
• 刊名：The Brazilian Journal of Infectious Diseases
• 出版年：2016
• 出版时间：November-December 2016
• 年：2016
• 卷：20
• 期：6
• 页码：556-563
• 全文大小：543 K

文摘

Carbapenem-resistant Acinetobacter baumannii (CRAb) is an important cause of nosocomial infections especially in intensive care units. This study aimed to assess clinical aspects and the genetic background of CRAb among ICU patients at a Brazilian teaching hospital.

Methods

56 critically ill patients colonized or infected by CRAb, during ICU stay, were prospectively assessed. Based on imipenem MIC ≥ 4 μg/mL, 28 CRAB strains were screened for the presence of genes encoding metallo-β-lactamases and OXA-type β-lactamases. The blaOXA-type genes were characterized by PCR using primers targeting ISAba-1 or -3. Genetic diversity of blaOXA-positive strains was determined by ERIC-PCR analysis.

Results

Patient's mean age (±SD) was 61 (±15.1), and 58.9% were male. Eighty-percent of the patients presented risk factors for CRAb colonization, mainly invasive devices (87.5%) and previous antibiotic therapy (77.6%). Thirty-three patients died during hospital stay (59.0%). Resistance to carbapenems was associated with a high prevalence of blaOXA-23 (51.2%) and/or blaOXA-143 (18.6%) genes. ERIC-PCR genotyping identified 10 clusters among OXA-producing CRAb. Three CRAb strains exhibited additional resistance to polymyxin B (MIC ≥ 4 μg/mL), whereas 10 CRAb strains showed tigecycline MICs > 2 μg/mL.

Conclusions

In this study, clonally unrelated OXA-123- and OXA-143-producing A. baumannii strains in ICU patients were strongly correlated to colonization with infected patients being associated with a poor outcome.