Geographical differences associated with single-nucleotide polymorphisms (SNPs) in nine gene targets among resistant clinical isolates of Mycobacterium tuberculosis.
J Clin Microbiol
; 52(5): 1322-9, 2014 May.
Article
en En
| MEDLINE
| ID: mdl-23784122
Alternative diagnostic methods, such as sequence-based techniques, are necessary for increasing the proportion of tuberculosis cases tested for drug resistance. Despite the abundance of data on drug resistance, isolates can display phenotypic resistance but lack any distinguishable markers. Furthermore, because resistance-conferring mutations develop under antibiotic pressure, different drug regimens could favor unique single-nucleotide polymorphisms (SNPs) in different geographical regions. A total of 407 isolates were collected from four geographical regions with a high prevalence of drug-resistant tuberculosis (India, Moldova, the Philippines, and South Africa). The "hot spot" or promoter sequences of nine genes (rpoB, gyrA, gyrB, katG, inhA promoter, ahpC promoter, eis promoter, rrs, and tlyA) associated with resistance to four types of antibiotics (rifampin, isoniazid, fluoroquinolones, and aminoglycosides) were analyzed for markers. Four genes contributed largely to resistance (rpoB, gyrA, rrs, and katG), two genes contributed moderately to resistance (the eis and inhA promoters), and three genes contributed little or no resistance (gyrB, tlyA, and the ahpC promoter) in clinical isolates. Several geographical differences were found, including a double mutation in rpoB found in 37.1% of isolates from South Africa, the CâT mutation at position -12 of the eis promoter found exclusively in 60.6% of isolates from Moldova, and the GâA mutation at position -46 of the ahpC promoter found only in India. These differences in polymorphism frequencies emphasize the uniqueness of isolates found in different geographical regions. The inclusion of several genes provided a moderate increase in sensitivity, and elimination of the examination of other genes might increase efficiency.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Tuberculosis Resistente a Múltiples Medicamentos
/
Polimorfismo de Nucleótido Simple
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Mycobacterium tuberculosis
Tipo de estudio:
Risk_factors_studies
País/Región como asunto:
Africa
/
Asia
/
Europa
Idioma:
En
Revista:
J Clin Microbiol
Año:
2014
Tipo del documento:
Article
País de afiliación:
Estados Unidos
Pais de publicación:
Estados Unidos