Pasqua Salvatore, Monaco Francesco, Cardinale Francesca, Bonelli Simone, Conaldi Pier Giulio, D'Apolito Danilo
Unità Prodotti Cellulari (GMP), Fondazione Ri.MED c/o IRCCS-ISMETT, Via E. Tricomi 5, 90127 Palermo, Italy.
Unità di Medicina di Laboratorio e Biotecnologie Avanzate, IRCCS-ISMETT (Istituto Mediterraneo per i Trapianti e Terapie ad Alta Specializzazione), Via E. Tricomi 5, 90127 Palermo, Italy.
Microorganisms. 2022 Oct 13;10(10):2026. doi: 10.3390/microorganisms10102026.
Theoretically, Aspergillus spp. grow in culture media, but frequently, blood cultures of patients with invasive Aspergillosis are negative, even if until now, the reasons are not clear. This aspect underlines the lack of a good strategy for the cultivation and isolation of Aspergillus spp. In order to develop a complete analytical method to detect Aspergillus in clinical and pharmaceutical samples, we investigated the growth performance of two blood culture systems versus the pharmacopeia standard method. At <72 h, all test systems showed comparable sensitivity, about 1−2 conidia. However, the subculture analysis showed a suboptimal recovery for the methods, despite the positive growth and the visualization of the “Aspergillus balls” in the culture media. To investigate this issue, we studied three different subculture approaches: (i) the use of a sterile subculture unit, (ii) the use of a sterile subculture unit and the collection of a larger aliquot (100 µL), following vigorous agitation of the vials, and (iii) to decapsulate the bottle, withdrawing and centrifuging the sample, and aliquot the pellet onto SDA plates. Our results showed that only the third procedure recovered Aspergillus from all positive culture bottles. This work confirmed that our strategy is a valid and faster method to culture and isolate Aspergillus spp. from blood culture bottles.
从理论上讲，曲霉菌属可在培养基中生长，但侵袭性曲霉病患者的血培养结果常常呈阴性，即便到目前为止，其原因尚不清楚。这一情况凸显了在曲霉菌属培养和分离方面缺乏有效的策略。为了开发一种完整的分析方法来检测临床和药物样本中的曲霉，我们研究了两种血培养系统与药典标准方法的生长性能。在72小时内，所有测试系统的灵敏度相当，约为1 - 2个分生孢子。然而，继代培养分析显示这些方法的回收率并不理想，尽管培养呈阳性且在培养基中可见“曲霉菌球”。为研究此问题，我们研究了三种不同的继代培养方法：（i）使用无菌继代培养装置；（ii）使用无菌继代培养装置，并在剧烈振荡小瓶后收集较大体积的等分试样（100微升）；（iii）打开瓶子，取出并离心样本，然后将沉淀等分接种到SDA平板上。我们的结果表明，只有第三种方法能从所有阳性培养瓶中培养出曲霉菌。这项工作证实，我们的策略是一种从血培养瓶中培养和分离曲霉菌属的有效且快速的方法。
