Publicação
μSTRAW: In-field detection of Escherichia coli
| Resumo: | Fast detection of Escherichia coli is required in multiple OneHealth settings, from bathing water to urinary tract infections (urine) and septicemia (i.e., blood infections). Current methods for bacteria enumeration are limited to lab-based conventional microbiology, requiring 2448 h. Nucleic acid testing represents an alternative, with high specificity and a broad range of targets. However, a scalable and affordable method for portable DNA extraction is missing, limiting point-of-care applications. To address that gap, we introduced STRAW, a compact gravity-driven microfluidic device for portable DNA extraction, which directly interfaces with a commercial, portable LAMP instrument. Using 45 mm-long, 10-bored 200 m i.d. microcapillary strips and a magnetic beads (MB)-based extraction kit, MB were captured and efficiently washed before DNA elution. STRAW offered simultaneous detection from 8 samples, and the usage of MB, lysis buffer, and proteinase K was reduced by 91, 83, and 65\% compared to the manufacturers protocol. Integration with portable LAMP showed a low limit of detection (LLoD) in the range of 10005000 CFU/mL in PBS within 120140 min, which improved to 50100 CFU/mL using a pre-concentration with a 0.22 m-pore-size syringe filter. STRAW also yielded an LLoD of 1001000 CFU/mL in synthetic urine, whereas in sheep blood, we observed an LLoD as low as 1023 CFU/mL upon 5 h of incubation in LB broth, which was therefore within the common CFU/mL found for bloodstream infections. The proposed approach is portable, affordable, scalable, and potentially transformative for a range of global OneHealth applications, especially bathing waters and wastewater. |
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| Autores principais: | Ianniello, Crescenzo |
| Outros Autores: | Kasprzyk-Hordern, Barbara; Reis, Nuno Miguel Fernandes |
| Assunto: | microfluidics DNA extraction LAMP Escherichia coli filtration urine blood |
| Ano: | 2026 |
| País: | Portugal |
| Tipo de documento: | artigo |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade do Minho |
| Idioma: | inglês |
| Origem: | RepositóriUM - Universidade do Minho |
| Resumo: | Fast detection of Escherichia coli is required in multiple OneHealth settings, from bathing water to urinary tract infections (urine) and septicemia (i.e., blood infections). Current methods for bacteria enumeration are limited to lab-based conventional microbiology, requiring 2448 h. Nucleic acid testing represents an alternative, with high specificity and a broad range of targets. However, a scalable and affordable method for portable DNA extraction is missing, limiting point-of-care applications. To address that gap, we introduced STRAW, a compact gravity-driven microfluidic device for portable DNA extraction, which directly interfaces with a commercial, portable LAMP instrument. Using 45 mm-long, 10-bored 200 m i.d. microcapillary strips and a magnetic beads (MB)-based extraction kit, MB were captured and efficiently washed before DNA elution. STRAW offered simultaneous detection from 8 samples, and the usage of MB, lysis buffer, and proteinase K was reduced by 91, 83, and 65\% compared to the manufacturers protocol. Integration with portable LAMP showed a low limit of detection (LLoD) in the range of 10005000 CFU/mL in PBS within 120140 min, which improved to 50100 CFU/mL using a pre-concentration with a 0.22 m-pore-size syringe filter. STRAW also yielded an LLoD of 1001000 CFU/mL in synthetic urine, whereas in sheep blood, we observed an LLoD as low as 1023 CFU/mL upon 5 h of incubation in LB broth, which was therefore within the common CFU/mL found for bloodstream infections. The proposed approach is portable, affordable, scalable, and potentially transformative for a range of global OneHealth applications, especially bathing waters and wastewater. |
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