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Updated: Jun 27, 2026
A High-throughput Platform for the Screening of Salmonella spp./Shigella spp.
Published on: November 7, 2018
Molecular detection of all 34 distinct O-antigen forms of Shigella
Yayue Li1,2,3,4,5, Boyang Cao5,1,6,3, Bin Liu3,6,5,1
1Tianjin Research Center for Functional Genomics and Biochips, 23 Hongda Street, TEDA, Tianjin 300457, PR China.
Abstract:
Shigella is the cause of shigellosis or bacillary dysentery, the occurrence of which is estimated to be 165 million cases per year worldwide, resulting in 1.1 million deaths. Rapid and reliable assays for detecting and identifying Shigella in food, environmental and clinical samples are therefore necessary. Shigella species are traditionally identified by their O antigens. This study developed a DNA microarray targeting O-serotype-specific genes to detect all 34 distinct O-antigen forms of Shigella, including Shigella boydii types 1-18, Shigella dysenteriae types 1-13, Shigella flexneri types 1-5 and 6, and Shigella sonnei. A total of 282 strains were used to test the specificity of the microarray, including 186 Shigella and Escherichia coli representative strains, 86 Shigella clinical isolates and ten strains of other bacterial species that are commonly isolated from food or clinical stool specimens. The oligonucleotide probes were printed on the microarray in concentrations from 1 to 100 muM, and 10 muM proved to be the optimal probe concentration. The detection sensitivity for each serotype was 50 ng genomic DNA or 1 c.f.u. in 25 g milk powder sample following a 6 h enrichment in broth. The microarray is specific, sensitive and reproducible, and, to our knowledge, is the first report of a microarray for serotyping all O-antigen forms of Shigella.
Insights
A new DNA microarray can rapidly identify all 34 O-antigen types of Shigella, the bacteria causing shigellosis. This advancement offers a sensitive and reproducible method for detecting this significant global health threat in various samples.
Area of Science:
- Microbiology
- Molecular Biology
- Diagnostics
Background:
- Shigella causes shigellosis (bacillary dysentery), leading to 1.1 million deaths annually worldwide.
- Accurate detection of Shigella in food, environmental, and clinical samples is crucial due to its high incidence.
- Traditional Shigella identification relies on O-antigen serotyping, which can be time-consuming.
Purpose of the Study:
- To develop a DNA microarray for the comprehensive serotyping of all Shigella O-antigen forms.
- To create a rapid, specific, and sensitive diagnostic tool for Shigella detection.
Main Methods:
- A DNA microarray was designed targeting O-serotype-specific genes of Shigella.
- The microarray was tested for specificity using 282 bacterial strains, including Shigella, Escherichia coli, and other common species.
- Optimal probe concentration was determined, and detection sensitivity was assessed using genomic DNA and spiked milk powder samples.
Main Results:
- The developed DNA microarray successfully identified all 34 distinct O-antigen forms of Shigella (S. boydii, S. dysenteriae, S. flexneri, S. sonnei).
- The optimal oligonucleotide probe concentration was found to be 10 µM.
- The assay demonstrated high sensitivity, detecting down to 50 ng genomic DNA or 1 c.f.u. per 25 g milk powder after enrichment.
Conclusions:
- This study presents the first DNA microarray capable of serotyping all O-antigen forms of Shigella.
- The microarray is specific, sensitive, and reproducible, offering a valuable tool for rapid Shigella identification.
- This technology has significant potential for improving the diagnosis and surveillance of shigellosis.
