Mendoza Rosmy, De Donato Marcos, de Waard Jacobus H, Takiff Howard, Bello Teresita, Chirinos Gladys
Laboratorio de Genética Molecular, Instituto de Investigaciones en Biomedicina y Ciencias Aplicadas "Dra. Susan Tai", Universidad de Oriente, Núcleo de Sucre, Cumaná, Venezuela.
Invest Clin. 2010 Dec;51(4):445-55.
The objective of this study was to evaluate the resistance to isoniazid (INH), rifampicin (RIF), streptomycin (STR) and ethambutol (EMB), with the Canetti's proportions method (PM) and the nitrate reductase assay (NRA) of 59 clinical strains of Mycobacterium tuberculosis, isolated in the period of august 2005 to december 2006, in Sucre state, Venezuela. Primary and acquired drug resistance was 6.3% and 14.3%, respectively. Only one strain was found to be multidrug resistant (MDR). The overall agreement between the NRA and PM was 100% for INH, RIF and EMB, and 96% for STR. The time to obtain results was 10 to 14 days for the NRA, compared to 42 days for the PM. The NRA was easy to perform and therefore represents a useful tool for rapid and accurate determination of drug-resistant M. tuberculosis. The sequence of the rpoB gene of the RIF resistant strain demonstrated a never described mutation (change in the codon 456; TCG > CAG) in the hypervariable region of 81 base pairs where most of the mutations of the RIF resistant strains have been reported. Comparison of our results with those of the last resistance prevalence study carried out in the years 1998-1999, shows a decrease in the studied area.
本研究的目的是采用卡内蒂比例法（PM）和硝酸还原酶测定法（NRA），对2005年8月至2006年12月期间在委内瑞拉苏克雷州分离出的59株临床结核分枝杆菌菌株进行异烟肼（INH）、利福平（RIF）、链霉素（STR）和乙胺丁醇（EMB）耐药性评估。原发性和获得性耐药率分别为6.3%和14.3%。仅发现1株多重耐药（MDR）菌株。NRA与PM之间对INH、RIF和EMB的总体一致性为100%，对STR为96%。NRA获得结果的时间为10至14天，而PM为42天。NRA操作简便，因此是快速准确测定耐药结核分枝杆菌的有用工具。耐RIF菌株的rpoB基因序列在81个碱基对的高变区显示出一种从未描述过的突变（密码子456处的变化；TCG > CAG），大多数耐RIF菌株的突变都在此区域报道。将我们的结果与1998 - 1999年进行的上一次耐药率研究结果相比较，显示研究区域的耐药率有所下降。
