Rapid Detection of Specific Gram-negative Microorganisms Causing Bloodstream Infections in Children with the Microarray Method

Abstract

Aim:Bloodstream infections are serious conditions that can cause significant morbidity and mortality. Early recognition of the bacteria and targeted early treatment play an important role in prognosis. The Verigene Gram-negative blood culture nucleic acid test (BC-GN; Nanosphere, USA) is a new method that can accurately identify both Gram-negative bacteria and resistance genes within 2 hours. In this study, we aimed to determine the accuracy of this assay for the rapid identification of certain Gram-negative microorganisms in children with bloodstream infections and to compare with the conventional culture method.Materials and Methods:A total of 30 patients (<18 years-old) (followed up in the Department of Pediatrics of Ege University Faculty of Medicine between December 2015-June 2016) with bloodstream infections due to Gram-negative bacteria were prospectively included. Microarray test results were compared with conventional blood culture results.Results:Klebsiella spp. (40%) were the most common and Acinetobacter spp. (20%) were the second most commonly seen Gram-negative microorganisms detected. Accurate identification via microarray analysis was 100% (12/12) for Klebsiella spp, 100% (6/6) for Acinetobacter spp. 100% (5/5) for Escherichia coli, 80% (4/5) for Enterobacter cloacae spp. 100% (1/1) for Pseudomonas aeruginosa and 100% (1/1) for Citrobacter amalonaticus respectively. The test was able to correctly identify 96.5% of Gram-negative microorganisms that were located in the test panel. CTX-M was the most common gene responsible for resistance.Conclusion:The Verigene Gram-negative (BC-GN) microarray test (Nanosphere) is a rapid method which can correctly identify the located Gram-negative microorganisms in the panel and give results much faster than conventional methods.

Keywords

• bloodstream infection
• child
• gram-negative
• microarray assay