英國研究人員日前報告說,，最近對一些曲霉菌感染者的化驗顯示,，這種細菌對現(xiàn)在常用的三唑類抗菌藥的耐藥性正在快速增強,，具有這種耐藥性的曲霉菌在逐漸傳播,，這種趨勢值得醫(yī)學界警惕,。
英國曼徹斯特大學研究人員在新一期美國《臨床傳染病》雜志上報告說，他們最近對一批感染曲霉菌的患者進行了化驗,，結(jié)果發(fā)現(xiàn)55%的被檢測者體內(nèi)的曲霉菌都具有一些耐藥性特征,，對常用于抗菌的三唑類藥物表現(xiàn)出耐藥性。而就在兩年前的一次檢查中,，這一比例還只是28%％,。
此外，還有跡象顯示具有耐藥性的曲霉菌正在廣泛傳播,。研究人員檢查了8名從未使用過三唑類藥物的病人,，結(jié)果發(fā)現(xiàn)其中6人體內(nèi)的曲霉菌也都有耐藥性。
研究人員戴維·丹寧說,，本次研究發(fā)現(xiàn)的曲霉菌耐藥性比例非常高,，數(shù)據(jù)顯示這種細菌的耐藥性正在快速增強，這值得醫(yī)療界警惕,。
他認為,，造成曲霉菌耐藥性增強的原因可能有兩個方面，一是現(xiàn)在農(nóng)業(yè)上使用的許多殺蟲劑都含有三唑類藥物成分,；一是在臨床治療中長期使用三唑類藥物,。這兩方面都可能使細菌在不致命劑量藥物的“鍛煉”下發(fā)展出耐藥性。
對人類而言,，曲霉菌常會導致肺部疾病,，會加重哮喘患者的癥狀，此外對那些有其他肺部感染或免疫系統(tǒng)受損的患者來說，也可能會使病情加重,。（生物谷Bioon.com）
生物谷推薦原文出處：
Clin Infect Dis. (2011) 52 (9): 1123-1129. doi: 10.1093/cid/cir179
High-frequency Triazole Resistance Found In Nonculturable Aspergillus fumigatus from Lungs of Patients with Chronic Fungal Disease
David W. Denning1,2,3, Steven Park4, Cornelia Lass-Florl5, Marcin G. Fraczek2,3, Marie Kirwan1,2, Robin Gore2, Jaclyn Smith2, Ahmed Bueid2, Caroline B. Moore3, Paul Bowyer2, and David S. Perlin2,4
Abstract
Background.?Oral triazole therapy is well established for the treatment of invasive (IPA), allergic (ABPA), and chronic pulmonary (CPA) aspergillosis, and is often long-term. Triazole resistance rates are rising internationally. Microbiological diagnosis of aspergillosis is limited by poor culture yield, leading to uncertainty about the frequency of triazole resistance.
Methods.?Using an ultrasensitive real-time polymerase chain reaction (PCR) assay for Aspergillus spp., we assessed respiratory fungal load in bronchoalveolar lavage (BAL) and sputum specimens. In a subset of PCR-positive, culture negative samples, we further amplified the CYP51A gene to detect key single-nucleotide polymorphisms (SNPs) associated with triazole resistance.
Results.?Aspergillus DNA was detected in BAL from normal volunteers (4/11, 36.4%) and patients with culture or microscopy confirmed IPA (21/22, 95%). Aspergillus DNA was detected in sputum in 15 of 19 (78.9%) and 30 of 42 (71.4%) patients with ABPA and CPA, compared with 0% and 16.7% by culture, respectively. In culture-negative, PCR-positive samples, we detected triazole-resistance mutations (L98H with tandem repeat [TR] and M220) within the drug target CYP51A in 55.1% of samples. Six of 8 (75%) of those with ABPA and 12 of 24 (50%) with CPA had resistance markers present, some without prior triazole treatment, and in most despite adequate plasma drug concentrations around the time of sampling.
Conclusions.?The very low organism burdens of fungi causing infection have previously prevented direct culture and detection of antifungal resistance in clinical samples. These findings have major implications for the sustainability of triazoles for human antifungal therapy.
