Abstract
Streptococcus agalactiae, (Group B Streptococcus (GBS)), is a common colonizer of the female vagina. In women giving birth it can be transmitted to the baby and cause serious illness and even death to the child. We have developed a biosensor comprising of phospholipids and fatty acids vesicles encapsulating high concentration, self-quenched carboxyfluorescein, which is released by the lysis of the vesicle by virulence factors expressed by GBS, becoming diluted and fluorescent. The microbial specificity of the sensor was tested against a number of GBS strains and other microbes including Candida albicans, Enterococcus faecalis and Staphylococcus epidermidis and a statistically significant response to GBS measured over these other microbes. To test the in vivo efficacy of the biosensor, a pilot study using donated lower vaginal swabs from non-pregnant women was conducted, where 58 female adults were recruited. Participants donated two swabs, one which was used for the vesicle test and one for the ‘gold standard’, enriched culture media (ECM) test. An overall GBS carriage rate of 17.2% was measured using the ECM test. The vesicle biosensor test took 45 min to obtain a result, and showed a sensitivity of 83.3%, specificity of 85.7% and accuracy of 85.3%. The test accuracy is in line with current novel GBS identification tests, with the advantage of being rapid, easy to use, low-cost and able to be conducted by bedside during start of labour.
Original language | English |
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Article number | 115923 |
Number of pages | 6 |
Journal | Biosensors and Bioelectronics |
Volume | 247 |
Early online date | 15 Dec 2023 |
DOIs | |
Publication status | Published - 1 Mar 2024 |
Bibliographical note
Data availability: Data provided in supplementary information and available on requestFunding
This work has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie SKŁODOWSKA-CURIE grant agreement No 955664. The authors thank Prof. Kirsty Le Doare at St Georges Hospital for clinical strains and Prof. Victor Nizet at the University of California for the GBS mutant strains.
Funders | Funder number |
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Horizon 2020 | 955664 |
Keywords
- Group B Streptococcus
- Lipid vesicles
- Point of care sensor
ASJC Scopus subject areas
- Biotechnology
- Biophysics
- Biomedical Engineering
- Electrochemistry