[Gene polymorphisms in the dihydrofolate reductase ( dhfr ) and dihydropteroate synthase ( dhps ) genes and structural modelling of the dhps gene in Colombian isolates of Toxoplasma gondii]. / Polimorfismos en los genes de dihidrofolato-reductasa ( dhfr ) y dihidropteroato-sintasa ( dhps ) y modelado estructural del gen dhps en aislamientos colombianos de Toxoplasma gondii.
Biomedica
; 34(4): 556-66, 2014.
Article
en Es
| MEDLINE
| ID: mdl-25504244
ABSTRACT
INTRODUCTION:
There are no reports describing polymorphisms in target genes of anti- Toxoplasma drugs in South American isolates.OBJECTIVE:
This study sought to perform cloning and sequencing of the dihydrofolate reductase ( dhfr ) and dihydropteroate-synthase ( dhps ) genes of the reference Rh strain and two Colombian isolates of Toxoplasma gondii . MATERIALS ANDMETHODS:
Two isolates were obtained from the cerebrospinal fluid of HIV-infected patients with cerebral toxoplasmosis. A DNA extraction technique and PCR assay for the dhfr and dhps genes were standardized, and the products of amplification were cloned into Escherichia coli and sequenced.RESULTS:
One polymorphism (A « G) was found at position 235 of exon 2 in the dhps gene. In addition, two polymorphisms (G « C) at positions 259 and 260 and one polymorphism (T « G) at position 371 within exon 4 of the dhps gene were detected. In this last exon, a bioinformatic analysis revealed a non-synonymous polymorphism in the coding region that could lead to the substitution of Glu (CAA or CAG) for His (encoded by codons AAU or AAC). A structural model of the T. gondii DHPS protein was calculated, and the results revealed modifications in secondary structure due to mutations.CONCLUSIONS:
The methods described in this study can be used as a tool to search for polymorphisms in samples from patients with different clinical manifestations of toxoplasmosis and to examine their relationship with the therapeutic response.
Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Tetrahidrofolato Deshidrogenasa
/
Toxoplasma
/
Proteínas Protozoarias
/
Polimorfismo de Nucleótido Simple
/
Dihidropteroato Sintasa
Tipo de estudio:
Clinical_trials
Límite:
Animals
/
Humans
/
Male
País/Región como asunto:
America do sul
/
Colombia
Idioma:
Es
Revista:
Biomedica
Año:
2014
Tipo del documento:
Article