基因型MTBDRplus在尼日利亚伊洛林临床分枝杆菌分离株中检测利福平及异烟肼耐药性的性能评估

Performance of Genotype MTBDRplus in the Detection of Resistance to Rifampicin and Isoniazid Among Clinical Mycobacteria Isolates in Ilorin, Nigeria.

作者信息

Nwofor Alfred C, Nyamngee Amaase, Nwabuisi Charles, Iwakun Mosunmola, Gidado Masur, Mensah Charles, Dakum Patrick, Agbede Oladjide O, Ndembi Nicaise, Blattner William A, Abimiku Alashle G

机构信息

Clinical Laboratory Services Department, Institute of Human Virology, Pent House, Main Court, Plot 252, Herbert Macaulay Way, Central Business District, Abuja, Nigeria.

出版信息

Curr HIV Res. 2015;13(4):308-14. doi: 10.2174/1570162x13666150407143147.

DOI:10.2174/1570162x13666150407143147

PMID:25845392

Abstract

BACKGROUND

Performance of Genotype MTBDRplus assay against Lowenstein Jensen (LJ) proportion method of Drug Susceptibility Testing (DST) in detection of resistance among clinical mycobacteria isolates to rifampicin (RMP) and isoniazid (INH) was evaluated in Ilorin, Nigeria.

METHODS

This retrospective study characterized one hundred mycobacteria isolates from pulmonary TB patients, stored on LJ medium and subcultured unto fresh LJ slants before being genotyped using MTBDRplus assay. DST was performed on the isolates against RMP, INH, Ethambutol and Streptomycin.

RESULTS

Genotype MTBDRplus identified 97% and 3% of the 100 isolates as Mycobacterium tuberculosis Complex (MTBC) and Non-Tuberculous Mycobacteria (NTM) respectively. Fourteen of the isolates, (14%) were resistant to RMP while 86% were sensitive by the genotypic method. Three of these 14 RMP-resistant isolates were NTMs while 11 were MTBC. Twelve (12%) of the 100 isolates were resistant to INH. Three INH-resistant isolates were NTMs, and 9 were MTBC. Phenotypically and genotypically, the 3 NTMs were resistant to RMP and INH and ten of the 97 MTBC strains were RMP-resistant. One RMP-phenotypically-sensitive strain was genotypically resistant to RMP. Six of the MTBC isolates were resistant to both RMP and INH by both methods. Most mutations occurred in the S-531L and S315T1 codons of rpoB and KatG genes of RMP and INH, respectively.

CONCLUSION

The high specificity and positive predictive values recorded by MTBDRplus in our study make it suitable for use in the programmatic management of drug-resistant TB in resource-limited settings.

摘要

背景

在尼日利亚伊洛林，评估了Genotype MTBDRplus检测法相对于罗氏培养基（LJ）比例法药敏试验在检测临床分枝杆菌分离株对利福平（RMP）和异烟肼（INH）耐药性方面的表现。

方法

这项回顾性研究对100株来自肺结核患者的分枝杆菌分离株进行了特征分析，这些菌株保存在LJ培养基上，并在重新接种到新鲜的LJ斜面后，使用MTBDRplus检测法进行基因分型。对这些分离株进行了针对RMP、INH、乙胺丁醇和链霉素的药敏试验。

结果

Genotype MTBDRplus将100株分离株中的97%鉴定为结核分枝杆菌复合群（MTBC），3%鉴定为非结核分枝杆菌（NTM）。14株（14%）分离株对RMP耐药，而基因分型法显示86%敏感。这14株对RMP耐药的分离株中有3株是NTM，11株是MTBC。100株分离株中有12株（12%）对INH耐药。3株对INH耐药的分离株是NTM，9株是MTBC。在表型和基因分型上，3株NTM对RMP和INH耐药，97株MTBC菌株中有10株对RMP耐药。1株表型对RMP敏感的菌株基因分型对RMP耐药。两种方法检测均显示，6株MTBC分离株对RMP和INH均耐药。大多数突变分别发生在RMP和INH的rpoB和KatG基因的S-531L和S315T1密码子上。