Introduction. Polymicrobial infections including yeasts and bacteria are not rare and patients with polymicrobial bloodstream infection have higher early and overall case fatality rates. The diagnosis of invasive fungal and bacterial infections is mainly based on blood culture. Aim. The aim was to reveal the effect of concomitant bacteraemia on the detection of fungi from blood cultures in the presence of polymicrobial bloodstream infections involving Candida and non-Candida fungi and to show the superiority of blood culture bottles including selective fungal media in such situations. Methodology. Twenty-four polymicrobial bloodstream infection models – involving one fungus and one bacterium – were constituted by using clinical blood culture isolates ( Escherichia coli , Staphylococcus aureus , Pseudomonas aeruginosa , Candida albicans, Candida glabrata, Fusarium solani and Trichosporon asahii). The Plus Aerobic/F (PAF) and Mycosis IC/F (MICF) culture bottles were used with the BACTEC 9240 device. After a bottle signalled positive, direct microscopic examination and subcultures on agar plates were performed. Results. All of fungi that were inoculated alone and in combination were detected by both direct microscopic examination and subcultures on agar plates from MICF bottles, whereas direct microscopic examination only revealed the bacterial agents from PAF bottles including combinations. Furthermore, fungal growth was hidden by bacterial growth on blood agar subcultures from PAF bottles including combinations of F. solani, C. glabrata or T. asahii with bacteria. Conclusion. Blood culture bottles including selective fungal media that can allow selective growth of fungi and earlier detection of some species should be preferred in addition to non-selective blood culture bottles, especially in specific patient populations. Further, the use of selective agar plates such as inhibitory mould agar may contribute to the solution of this problem in clinical laboratories.

中文翻译：

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伴随的菌血症会在血液培养物中隐藏真菌吗？体外研究。

介绍。包括酵母菌和细菌在内的多种微生物感染并不罕见，具有多种微生物血流感染的患者的早期和整体病死率更高。侵袭性真菌和细菌感染的诊断主要基于血液培养。目标。目的是揭示在存在涉及念珠菌和非念珠菌的多微生物血液感染的情况下，伴随菌血症对血液培养中真菌检测的影响，并显示出在这种情况下包括选择性真菌培养基在内的血液培养瓶的优越性。方法。通过使用临床血液培养分离株（大肠杆菌，金黄色葡萄球菌，铜绿假单胞菌，白色念珠菌，光滑念珠菌，茄枯萎病菌和Aschoii毛孢霉菌），建立了24种涉及一种真菌和一种细菌的多微生物血液感染模型。BACTEC 9240设备使用Plus有氧/ F（PAF）和Mycosis IC / F（MICF）培养瓶。瓶子发出阳性信号后，直接进行显微镜检查并在琼脂板上进行亚培养。结果。 通过直接显微镜检查和在来自MICF瓶的琼脂平板上的继代培养，均可检测到所有单独和组合接种的真菌，而直接显微镜检查仅显示了包括组合的PAF瓶中的细菌。此外，在PAF瓶的血琼脂亚培养中，细菌的生长被细菌的生长所掩盖，其中包括sol。solani，C。glabrata或T. asahii与细菌的结合。结论。除非选择性血液培养瓶外，尤其是在特定的患者人群中，应优先使用包括选择性真菌培养基的血液培养瓶，该培养基可以允许真菌的选择性生长和早期检测某些物种。此外，使用选择性琼脂平板如抑制性霉菌琼脂可能有助于临床实验室解决该问题。