Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran.
Department of Mycobacteriology and Pulmonary Research, Pasteur Institute of Iran, Tehran, Iran.
Sci Rep. 2017 Jan 25;7:41410. doi: 10.1038/srep41410.
Mixed strain infections of Mycobacterium tuberculosis make diagnosis, treatment, and control of tuberculosis (TB) more difficult. This study was aimed to evaluate the relationship between mixed infections, antibiotic resistance patterns and treatment of TB patients. In this study, among 2850 suspected TB clinical samples, a total of ninety-six clinical samples from 66 TB confirmed patients were subjected to the 24-locus variable-number tandem repeat method to evaluate the prevalence of mixed infections. For all studied strains, 288 colonies (three individual clones for each sample) were isolated from different colonies and separately analyzed by the Drug Susceptibility Test (DST). For all patients, follow up was done after 6 months of treatment. Based on direct 24 loci MIRU-VNTR, in the 66 TB patients, 53% (35/66) showed mixed infection. In the mixed samples, 45.71% (16/35) showed different antibiotic resistant patterns. Among the mixed infection patients, eight (22.9%; 8/35) showed treatment failure after six- month therapy. Six of these non-treated patients (75%; 6/8) had different antibiotic resistant patterns. We conclude that mixed infections, have a negative impact on treatment of TB patients especially when co-infecting M. tuberculosis strains display heteroresistance.
结核分枝杆菌混合株感染使结核病（TB）的诊断、治疗和控制更加困难。本研究旨在评估混合感染、抗生素耐药模式与 TB 患者治疗之间的关系。在这项研究中，在 2850 份疑似结核病临床样本中，共有 66 名结核病确诊患者的 96 份临床样本采用 24 位位可变数目串联重复（VNTR）方法进行了混合感染的流行率评估。对所有研究菌株，从不同的菌落中分离出 288 个菌落（每个样本三个单独的克隆），并单独进行药物敏感性试验（DST）分析。对所有患者，在治疗 6 个月后进行随访。基于直接的 24 位位 MIRU-VNTR，在 66 名结核病患者中，53%（35/66）显示混合感染。在混合样本中，45.71%（16/35）显示出不同的抗生素耐药模式。在混合感染患者中，有 8 名（22.9%；8/35）在 6 个月的治疗后治疗失败。这些未治疗的患者中有 6 名（75%；6/8）显示出不同的抗生素耐药模式。我们得出结论，混合感染对结核病患者的治疗有负面影响，尤其是当共感染的结核分枝杆菌菌株显示异质性耐药时。
