MALDI-TOF mass spectrometry for direct KPC detection among Enterobacterales

Autor: Afonso Barth, Natália Kehl Moreira, Camila M. Wilhelm, JULIANA CAIERAO, Priscila Wink
Rok vydání: 2022
Předmět:
Zdroj: Brazilian journal of microbiology : [publication of the Brazilian Society for Microbiology]. 53(4)
ISSN: 1678-4405
Popis: In this study, we evaluate a method for the KPC enzyme detection, using MALDI-TOF MS, for Enterobacterales. A total of 300 clinical Enterobacterales isolates were selected. The collection included 259 carbapenemase-producing (157 KPC and 102 non-KPC) and 41 carbapenemase non-producing isolates. Bacterial proteins were extracted from Mueller-Hinton agar plates using formic acid, isopropyl alcohol, and water (17:33:50). Samples were prepared with a double layer of synapinic acid. Analyses were performed using a Microflex LT mass spectrometer (Bruker Daltonics) and flexAnalysis 4.0 software (Bruker Daltonics). Statistical analyses were performed using SPSS Software. A distinctive peak at m/z 28,643-28,731 was found in all 157 KPC-producing isolates, and it was consistently absent in the 143 KPC non-producing group. KPC-producing peak intensities ranged from 77 to 3893. Considering an intensity cutoff value ≥ 120 for the presence of KPC, this methodology presented 98.09% and 97.90% of sensitivity and specificity, respectively.
Databáze: OpenAIRE