This study explored the prevalence, genetic diversity, and population structure of azole-resistant Aspergillus fumigatus (ARAf) at Walailak University in Southern Thailand. Three hundred samples were collected from dwellings and workplaces, screened for azole resistance, and tested for drug susceptibility. Molecular detection of alterations in the cyp51A gene and CSP1 typing was performed. Nucleotide polymorphism and haplotype diversity were calculated, and selective neutrality tests were performed. In total, 62 A. fumigatus isolates were identified, with 17 isolates displaying resistance to medical azoles. The prevalence of ARAf in the A. fumigatus isolates was 27.4%. Almost all azole-resistant isolates harboured an amino acid substitution in the hotspot region of the cyp51A gene, especially at or nearby the G54 residue that has been reported as a cause of azole resistance arising from long-term azole treatment. Moreover, some of the ARAf isolates harboured tandem repeats in the promoter region, which have been reported as a cause of resistance arising from the use of azole fungicides in crop protection. Finally, selective neutrality testing also suggested an impact of natural selection on DNA diversity. Therefore, we hypothesize that the factors causing the high prevalence of ARAf in this area are both in vivo- and ex vivo-acquired resistance.

中文翻译：

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泰国南部瓦莱拉克大学室内环境中单一祖先来源的耐唑类烟曲霉的高流行率和遗传多样性

本研究探讨了泰国南部瓦莱拉克大学耐唑类烟曲霉(AR Af ) 的流行率、遗传多样性和种群结构。从住宅和工作场所收集了 300 份样本，筛选了唑类耐药性，并测试了药物敏感性。对cyp51A基因的改变和CSP1分型进行了分子检测。计算核苷酸多态性和单倍型多样性，并进行选择性中性试验。共鉴定出 62株烟曲霉分离株，其中 17 株对医用唑类表现出耐药性。烟曲霉中 AR Af的患病率分离株为 27.4%。几乎所有的唑类耐药菌株在cyp51A基因的热点区域都有一个氨基酸取代，特别是在 G54 残基处或附近，据报道这是长期唑类治疗引起唑类耐药的原因。此外，一些 AR Af分离株在启动子区域含有串联重复序列，据报道这是由于在作物保护中使用唑类杀真菌剂而引起的抗性原因。最后，选择性中性测试也表明了自然选择对 DNA 多样性的影响。因此，我们假设导致该地区 AR Af高流行的因素是体内和体外获得性耐药。