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Updated: May 11, 2026
08:04
Determination of Sialic Acids in Liver and Milk Samples of Wild-type and CMAH Knock-out Mice.
Published on: July 14, 2017
Sialic acid utilization by Cronobacter sakazakii.
Susan Joseph1, Sumyya Hariri, Naqash Masood
1Pathogen Research Centre, School of Science and Technology, Nottingham Trent University, Clifton Lane, Nottingham NG11 8NS, UK. stephen.forsythe@ntu.ac.uk.
Microbial Informatics and Experimentation
|May 28, 2013
Summary
Cronobacter sakazakii uniquely utilizes sialic acid for growth, a key virulence factor in infant infections. This co-evolution with the mammalian host may explain its pathogenicity.
Area of Science:
- Microbiology
- Genomics
- Pathogenesis
Background:
- Cronobacter sakazakii causes severe neonatal infections like meningitis and necrotizing enterocolitis.
- A unique gene cluster (nanAKT) for sialic acid utilization is present in C. sakazakii.
- Sialic acid is abundant in milk, mucins, and brain gangliosides, making its metabolism a potential virulence factor.
Purpose of the Study:
- To investigate the phylogenetic distribution of the nanAKT gene cluster in Cronobacter species.
- To determine if C. sakazakii can utilize sialic acid as a carbon source.
- To explore the evolutionary relationship between C. sakazakii and sialic acid metabolism.
Main Methods:
- Phylogenetic analysis of nan genes in 19 Cronobacter strains.
- Laboratory growth studies using sialic acid as a sole carbon source.
- Genomic analysis to identify potential sialidase genes.
Main Results:
- The nanAKTR genes formed a unique cluster in C. sakazakii, distinct from other Enterobacteriaceae.
- Only C. sakazakii, among the seven Cronobacter species, could grow using sialic acid.
- No specific sialidase genes were identified; β-galactosidase activity likely contributes to substrate degradation.
Conclusions:
- Sialic acid utilization by C. sakazakii may represent co-evolution with the mammalian host.
- This metabolic capability could be a significant virulence factor, contributing to severe infections in neonates.
- The ability to metabolize sialic acid from various sources (breast milk, host tissues) enhances C. sakazakii's pathogenicity.
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