OBJECTIVE To provide scientific and reasonable recommendations for the identification of Anaerobiospirillum succiniciproducens in clinical microbiology laboratories by comparing the effectiveness of biochemical methods, matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS), and 16S rRNA gene sequencing.

METHODS Methodological evaluation was conducted. A strain of A. succiniciproducens was isolated on Mar. 27, 2023 from a patient with sepsis caused by a dog bite, who was admitted to Guangdong Nongken Central Hospital, and analyzed for the morphological characteristics, culture methods, and colony features. The identification of the isolated strain was conducted by the automated microbial identification and analysis system (VITEK 2 Compact 2, bioMerieux), MALDI-TOF MS including VITEK MS, MALDI Biotyper, Autof ms 1000, and EX-Accuspec, as well as 16S ribosomal RNA (rRNA) gene sequencing. The performance of each method was evaluated.

RESULTS A. succiniciproducens was a strictly anaerobic gram-negative spiral bacterium, characterized by slow growth, flat and colorless transparent colonies, and negative oxidase and catalase activity. When using VITEK 2 Compact ANC card, it was not successfully recognized; however, through the identification by VITEK MS, MALDI Biotyper, Autof ms 1000 and EX-Accuspec, it was all confirmed as A. succiniciproducens. Additionally, 16S rRNA gene sequencing technology also identified it as A. succiniciproducens.

CONCLUSIONS Current automated biochemical identification systems are unable to accurately identify A. succiniciproducens. MALDI-TOF MS and 16S rRNA gene sequencing techniques can reliably confirm A. succiniciproducens. Clinical microbiologists should select the appropriate identification method based on their available resources.