Related Experiment Video
Updated: Nov 5, 2025
Identification of Rare Bacterial Pathogens by 16S rRNA Gene Sequencing and MALDI-TOF MS
Published on: July 11, 2016
MALDI-TOF Mass Spectrometry and 16S rRNA Gene Sequence Analysis for the Identification of Foodborne Clostridium Spp
Irshad M Sulaiman1, Nancy Miranda1, Steven Simpson1
1U.S. Food and Drug Administration, Microbiological Sciences Branch, Southeast Food and Feed Laboratory, Office of Regulatory Science, Office of Regulatory Affairs, 60 8th St NE, Atlanta, GA, 30309, USA.
Background:
Clostridium is a genus of Gram-positive, spore-forming, anaerobic bacteria comprising approximately 100 species. Some Clostridium spp. (C. botulinum, C. perfringens, C. tetani, and C. difficile) have been recognized to cause acute food poisoning, botulism, tetanus, and diarrheal illness in humans. Thus, rapid identification of Clostridium spp. is critical for source-tracking of contaminated food and to understand the transmission dynamics of these foodborne pathogens.
Objective:
This study was carried out to rapidly identify Clostridium-like isolates by matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) MS and rRNA sequencing methods.
Method:
Thirty-three Clostridium-like isolates were recovered from various baby food and surveillance samples. Species identification of these isolates was accomplished using the VITEK MS system. Sequence characterization of the 16S rRNA region was done on an ABI 3500xL Genetic Analyzer.
Results:
The VITEK MS system identified 28 of the 33 Clostridium-like isolates with a high confidence value (99.9%); no identification was observed for the remaining five isolates. Nucleotide sequencing of the 16S rRNA region identified all 33 Clostridium-like isolates. Furthermore, while characterizing the 16S rRNA gene, 11 distinct Clostridium spp. (Clostridium aciditolerans, Clostridium aerotolerans, Clostridium argentinense, Clostridium beijerinckii, Clostridium bifermentans, Clostridium butyricum, Clostridium cochlearium, Clostridium difficile, Clostridium perfringens, Clostridium sporogenes, and Clostridium subterminale) were recognized among the 33 Clostridium-like isolates. One of the Clostridium-like isolates was identified as Citrobacter amalonaticus by both diagnostic methods. The generated 16S rRNA sequences matched completely (100%) with sequences available in GenBank for Clostridium and Citrobacter species. Species identification attained using the VITEK MS for the Clostridium-like isolates was comparable to that from the 16S rRNA sequencing-based data.
Conclusions:
The VITEK MS and 16S rRNA sequence analysis can be implemented in the species identification of Clostridium spp. isolates of public health importance.
Highlights:
MALDI-TOF MS and 16S rRNA sequencing can be used in the species identification of Clostridium species.
Related Concept Videos
01:19MALDI-TOF Mass Spectrometry
Matrix-assisted laser desorption ionization (MALDI) is a commonly...
01:29Modern Molecular Taxonomy
01:20Applications of Molecular Taxonomy
01:28Methods of Classification and Identification
01:33Peptide Identification Using Tandem Mass Spectrometry
This technique helps gather information regarding the protein from which the peptide was obtained and to study the peptides’ amino acid sequence. Identifying peptides from a complex mixture is an important component of the growing field of...