Mycology Reference Laboratory, National Centre for Microbiology, Instituto de Salud Carlos III, Madrid, Spain.
Infectious Diseases Department, Hospital Universitari Vall d'Hebron, Medicine Department, Autonomous University of Barcelona, Barcelona, Spain.
Clin Microbiol Infect. 2017 Jan;23(1):49.e1-49.e8. doi: 10.1016/j.cmi.2016.09.016. Epub 2016 Sep 24.
Paradoxical growth (PG) and trailing effect (TE) are frequently observed during antifungal susceptibility testing (AFST). These two phenomena interfere with the determination of the minimal inhibitory concentration (MIC). The aim of this study was to assess the clinical impact of TE and PG.
We analysed the frequency of TE and PG of 690 Candida isolates collected from a population-based study performed in Spain (CANDIPOP) and correlated the results with clinical outcome of the patients.
Around 70% (484/690) of the isolates exhibited TE to azoles. Candida tropicalis showed the highest presence of TE (39/53 isolates exhibited residual growth >25% of control). No TE was seen in most of the isolates from the psilosis complex. PG was mainly associated with echinocandins. In patients treated with fluconazole within the first 48 hours after blood sampling (n = 221), the presence of TE to azoles tended to be associated with lower 30-day mortality (odds ratio (OR) 0.55, 95% confidence interval (CI) 0.25-1.00) but not with clinical failure (OR 0.85, 95% CI 0.45-1.54). In the subgroup of 117 patients treated with echinocandins, the presence of PG was not associated with patient's response to antifungal treatment (OR for 30-day mortality 1.63, 95% CI 0.76-4.03; OR for clinical failure 1.17, 95% CI 0.53-2.70).
TE or PG are widely expressed among Candida spp., although they do not seem to influence clinical outcome.
抗真菌药敏试验（AFST）中常观察到反常生长（PG）和拖尾效应（TE）。这两种现象会干扰最小抑菌浓度（MIC）的测定。本研究旨在评估 TE 和 PG 的临床影响。
我们分析了西班牙一项基于人群的研究（CANDIPOP）中收集的 690 株念珠菌分离株的 TE 和 PG 频率，并将结果与患者的临床结果相关联。
约 70%（484/690）的分离株对唑类药物表现出 TE。热带念珠菌表现出最高的 TE 存在（39/53 株分离株表现出>25%的对照残留生长）。大多数来自近平滑念珠菌复合体的分离株未见 TE。PG 主要与棘白菌素相关。在血样采集后 48 小时内接受氟康唑治疗的患者（n=221）中，唑类药物 TE 的存在倾向于与较低的 30 天死亡率相关（比值比（OR）0.55，95%置信区间（CI）0.25-1.00），但与临床失败无关（OR 0.85，95%CI 0.45-1.54）。在接受棘白菌素治疗的 117 例患者亚组中，PG 的存在与患者对抗真菌治疗的反应无关（30 天死亡率的 OR 为 1.63，95%CI 为 0.76-4.03；临床失败的 OR 为 1.17，95%CI 为 0.53-2.70）。
TE 或 PG 在念珠菌属中广泛表达，尽管它们似乎不影响临床结果。
