Dipstick test for rapid diagnosis of Shigella dysenteriae 1 in bacterial cultures and its potential use on stool samples.
PLoS One
; 6(10): e24830, 2011.
Article
en En
| MEDLINE
| ID: mdl-21984895
ABSTRACT
BACKGROUND:
We describe a test for rapid detection of S. dysenteriae 1 in bacterial cultures and in stools, at the bedside of patients. METHODOLOGY/PRINCIPALFINDINGS:
The test is based on the detection of S. dysenteriae 1 lipopolysaccharide (LPS) using serotype 1-specific monoclonal antibodies coupled to gold particles and displayed on a one-step immunochromatographic dipstick. A concentration as low as 15 ng/ml of LPS was detected in distilled water and in reconstituted stools in 10 minutes. In distilled water and in reconstituted stools, an unequivocal positive reaction was obtained with 1.6×106 CFU/ml and 4.9×106 CFU/ml of S. dysenteriae 1, respectively. Optimal conditions to read the test have been determined to limit the risk of ambiguous results due to appearance of a faint yellow test band in some negative samples. The specificity was 100% when tested with a battery of Shigella and unrelated strains in culture. When tested on 328 clinical samples in India, Vietnam, Senegal and France by laboratory technicians and in Democratic Republic of Congo by a field technician, the specificity (312/316) was 98.7% (95% CI96.6-99.6%) and the sensitivity (11/12) was 91.7% (95% CI59.8-99.6%). Stool cultures and the immunochromatographic test showed concordant results in 98.4 % of cases (323/328) in comparative studies. Positive and negative predictive values were 73.3% (95% CI44.8-91.1%) and 99.7% (95% CI98-100%).CONCLUSION:
The initial findings presented here for a simple dipstick-based test to diagnose S. dysenteriae 1 demonstrates its promising potential to become a powerful tool for case management and epidemiological surveys.
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Juego de Reactivos para Diagnóstico
/
Shigella dysenteriae
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Técnicas Bacteriológicas
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Disentería Bacilar
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Heces
Tipo de estudio:
Diagnostic_studies
/
Prognostic_studies
Límite:
Adolescent
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Adult
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Animals
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Child
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Child, preschool
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Humans
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Middle aged
País/Región como asunto:
Asia
Idioma:
En
Revista:
PLoS One
Asunto de la revista:
CIENCIA
/
MEDICINA
Año:
2011
Tipo del documento:
Article
País de afiliación:
India