Evaluation of the Consistency of MALDI-TOF Results with Traditional Methods for the Identification of Urease-producing Enterobacteriaceae in Wastewater from Abidjan, Côte d'Ivoire

Abstract

The aim of this study was to evaluate the concordance between Matrix-Assisted Laser Desorption/Ionization-Time of Flight (MALDI-TOF) mass spectrometry and traditional biochemical methods for identifying urease-producing Enterobacteria in wastewater samples. This research was a comparative study assessing the efficacy of MALDI-TOF mass spectrometry versus traditional biochemical methods for bacterial identification. The study was conducted in Abidjan over a period of five weeks. A total of 50 wastewater samples were collected for analysis. The samples underwent a two-step enrichment process: initial pre-enrichment in EPT broth at 37°C for 18-24 hours, followed by enrichment in RV10 broth at 42°C for 24 hours. Subsequently, isolates were cultured on Hektoen agar, observed for specific colony characteristics, and subjected to the urease test. Final identification was performed using MALDI-TOF mass spectrometry. Of the 50 samples, 46 produced identifiable colonies. The distribution of identified species was as follows: Proteus mirabilis in 22 samples (47.82%), Providencia stuartii in 16 samples (34.78%), and Klebsiella pneumoniae in 8 samples (17.39%). MALDI-TOF mass spectrometry demonstrated over 90% concordance with traditional biochemical methods, accurately identifying bacterial species with high precision. MALDI-TOF mass spectrometry proved to be a rapid, precise, and efficient method for identifying urease-producing Enterobacteria in wastewater. Its high concordance with traditional methods suggests its potential to replace conventional techniques in microbiological laboratories, enhancing the speed and accuracy of bacterial identification in water quality management.