Commentary on clinical utility of whole genome sequencing and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.

3The present study is commentary and aims to evaluate the practical application of Whole Genome Sequencing (WGS) and Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry (MALDI-TOF MS) in clinical microbiology. The MALDI-TOF MS method has been replaced cultural and biochemical tests for species identification in most laboratories worldwide. Moreover, WGS has elevated the discriminatory power by detection of single nucleotide polymorphisms (SNPs), and helped with the identification of microorganisms that were misidentified by previous culture and biochemical tests. Moreover, WGS can be used in epidemiological studies (e.g. clinical outbreaks) by tracking of phylogenetic maps and analyzing SNP distance; antimicrobial resistance studies such as the study of antimicrobial resistance genes, e.g. CTX-M, NDM, KPC, or OXA; and the study of recombination of plasmid or insertion sequence (IS) elements to elucidate the mechanism of antimicrobial resistance. MALDI-TOF technology is used for bacterial or fungal species identification in most laboratories. VITEK MS (bioMérieux) and Biotyper (Bruker Daltonics) are examples of commercially available MALDI-TOF MS systems. The technique has been used for direct identification of organisms from blood culture bottles, markedly shortening the identification time. Beta-lactamases or carbapenemases have been detected by analyzing specific protein peaks using MALDI-TOF MS. Shiga toxin-producing Escherichia coli, Salmonella serotype, and Vibrio phenotypes can also be detected.