Improvement in cyst recovery and molecular detection of Giardia duodenalis from stool samples.
Mol Biol Rep
; 47(2): 1233-1239, 2020 Feb.
Article
en En
| MEDLINE
| ID: mdl-31813130
Molecular detection of Giardia duodenalis by polymerase chain reaction (PCR) is difficult in faecal samples due to inhibitors that contaminate DNA preparations, or due to low cyst concentrations. In order to eliminate inhibitors, improve cyst recovery and molecular detection of G. duodenalis, different types of water, distillates (MDs), deionized (MDz), injection (MI) or Milli-Q® (MM) were used instead of formaldehyde (F) in the laboratory routine method (Ritchie). Cysts were isolated from faecal samples with low cyst concentrations (< 1 cyst/field), medium (1-2 cysts/field) or high (> 2 cysts/field). Cyst recovery was improved using all water types (MDs, MDz, MI, MM) compared to formaldehyde. At all cyst concentrations, the use of MM consistently showed the greatest recovery of G. duodenalis cysts . DNA samples from recovered cysts were tested for the glutamate dehydrogenase (GDH) and ß-giardin (ßg) genes. The use of Milli-Q® water allowed to detect both genes in all cyst concentrations, including low. The method processed with the other types of water amplified these genes at high and medium cyst concentrations. GDH and ßg genes were not detected when the sample was processed with formaldehyde. These experimental results were confirmed in clinical samples. The results suggest that Milli-Q® water provides the highest cyst recovery from stool samples and, correspondingly, the highest sensitivity for detecting G. duodenalis by microscopy or PCR for GDH and ßg genes, even at low concentration of cysts.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Giardiasis
/
Giardia lamblia
/
Técnicas de Diagnóstico Molecular
/
Heces
Tipo de estudio:
Diagnostic_studies
Límite:
Humans
Idioma:
En
Revista:
Mol Biol Rep
Año:
2020
Tipo del documento:
Article
País de afiliación:
Brasil
Pais de publicación:
Países Bajos