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Abundant production of exopolysaccharide by EAEC strains enhances the formation of bacterial biofilms in contaminated sprouts
- Source :
- Gut Microbes. 9:264-278
- Publication Year :
- 2018
- Publisher :
- Informa UK Limited, 2018.
-
Abstract
- Enteroaggregative E. coli (EAEC) is associated with food-borne outbreaks of diarrhea and growth faltering among children in developing countries. A Shiga toxin-producing EAEC strain of serotype O104:H4 strain caused one of the largest outbreaks of a food-borne infection in Europe in 2011. The outbreak was traced to contaminated fenugreek sprouts, yet the mechanisms whereby such persistent contamination of sprouts could have occurred are not clear. We found that under ambient conditions of temperature and in minimal media, pathogenic Shiga toxin-producing EAEC O104:H4 227-11 and non-Shiga toxin-producing 042 strains both produce high levels of exopolysaccharide structures (EPS) that are released to the external milieu. The exopolysaccharide was identified as colanic acid (CA). Unexpectedly, Shiga-toxin producing EAEC strain 227-11 produced 3-6-fold higher levels of CA than the 042 strain, suggesting differential regulation of the CA in the two strains. The presence of CA was accompanied by the formation of large biofilm structures on the surface of sprouts. The wcaF-wza chromosomal locus was required for the synthesis of CA in EAEC 042. Deletion in the glycosyltransferase wcaE gene abolished the production of CA in 042, and resulted in diminished adherence to sprouts when co-cultured at ambient temperature. In conclusion, this work suggests that copious production of CA may contribute to persistence of EAEC in the environment and suggests a potential explanation for the large Shiga toxin-producing EAEC outbreak in 2011.
- Subjects :
- 0301 basic medicine
Microbiology (medical)
Serotype
030106 microbiology
medicine.disease_cause
Polysaccharide
Microbiology
Bile Acids and Salts
03 medical and health sciences
Bacterial Proteins
Polysaccharides
Glycosyltransferase
Escherichia coli
medicine
Humans
Food microbiology
Escherichia coli Infections
chemistry.chemical_classification
biology
Genetic Complementation Test
Polysaccharides, Bacterial
Gastroenterology
Biofilm
Outbreak
Gene Expression Regulation, Bacterial
Diarrhea
030104 developmental biology
Infectious Diseases
chemistry
Genes, Bacterial
Seedlings
Biofilms
Food Microbiology
biology.protein
medicine.symptom
Gene Deletion
Genome, Bacterial
Research Paper
Subjects
Details
- ISSN :
- 19490984 and 19490976
- Volume :
- 9
- Database :
- OpenAIRE
- Journal :
- Gut Microbes
- Accession number :
- edsair.doi.dedup.....a1f8f6472112e06f21c9590a01b6908e