Development of a LAMP method for detection of carbapenem-resistant Acinetobacter baumannii during a hospital outbreak
Carolina Garciglia Mercado, Ramón Gaxiola‐Robles, Felipe Ascencio, Jesús Silva-Sánchez, M. Teresa Estrada‐Garcia, Gracia Goméz‐Anduro
Abstract
INTRODUCTION: Carbapenem-resistant A. baumannii (CRAB) represents a public health threat increasing worldwide. We assess the suitability of a loop-mediated isothermal amplification (LAMP) method for on-site screening of CRAB in a hospital facility. METHODOLOGY: A set of six primers were designed for recognizing eight distinct sequences on six targets: blaOXA-23-like, blaOXA-24-like, blaOXA-51-like, blaOXA-58-like, blaIMP, and blaVIM. A LAMP method was developed, optimized and evaluated for the identification of CRAB in thirty-three environmental samples from an outbreak in an Intensive Care Unit (ICU) facility. RESULTS: The sensitivity of the LAMP assay for the detection of A. baumannii was ten-fold higher than the PCR assay (1.0 ng.µL-1). The LAMP assays showed a higher detection rate for CRAB samples and robust diagnosis performance in comparison to a conventional PCR, with clinical sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of 100% for blaOXA-23-like, blaOXA-51-like and blaVIM. CONCLUSIONS: The developed LAMP assays are powerful tools that can be useful in on-site screening of CRAB causing local outbreaks in clinics and hospitals facilities where costs and equipment restraints are imperative.