Ataturk Training and Research Hospital, Microbiology Laboratory, Izmir Katip Celebi University, Izmir, Turkey.
Institute of Health Sciences, Department of Basic Oncology, Ege University, Izmir, Turkey.
Am J Trop Med Hyg. 2023 Mar 20;108(5):895-900. doi: 10.4269/ajtmh.22-0506. Print 2023 May 3.
Infections are still among the most important causes of morbidity and mortality in patients with lung cancer, which has the highest rate of cancer-related deaths in the world. Microsporidia, which are opportunistic parasitic fungi, primarily localize to the intestine by ingestion but can disseminate to the respiratory tract or can be acquired by spore inhalation. Cancer patients are at higher risk for microsporidia, a life-threatening infection, than the normal population is. We aimed to characterize the prevalence of microsporidia infection for the first time by evaluating the intestinal and respiratory tracts of patients with lung cancer. In this study, we investigated 98 patients with lung cancer and 103 healthy individuals for microsporidia infection and evaluated the clinical findings of patients who were found to be positive. Sputum and stool samples were tested by microscopic examination, in addition to pan-microsporidia and genus-specific polymerase chain reactions. Nine patients with lung cancer had positive results for microsporidia (9.2%), which was significantly higher than the rate in healthy individuals (P = 0.008), and most of them had clinical findings. Among these positive patients, polymerase chain reaction revealed microsporidia in the sputum samples of seven patients, the stool sample of one patient, and both the sputum and stool samples of one patient. Encephalitozoon cuniculi was identified as the predominant pathogen in 87.5% (7/8) of positive sputum samples. Microsporidia infection was significantly associated with advanced stages of cancer. However, in the control group, Encephalitozoon intestinalis was detected in the stool sample of an individual without clinical symptoms. Microsporidia, especially E. cuniculi, should be considered as a cause of respiratory tract infection as well as intestinal infection in cancer patients and should be screened in respiratory samples of these patients when they have pulmonary symptoms.
在肺癌患者中，感染仍然是发病率和死亡率的重要原因之一，而肺癌是全球癌症相关死亡人数最多的癌症。微孢子虫是一种机会性寄生真菌，主要通过摄入定殖于肠道，但也可以传播到呼吸道，或者通过孢子吸入获得。癌症患者感染微孢子虫（一种危及生命的感染）的风险比普通人群更高。我们旨在通过评估肺癌患者的肠道和呼吸道，首次描述微孢子虫感染的流行情况。在这项研究中，我们调查了 98 例肺癌患者和 103 例健康个体的微孢子虫感染情况，并评估了发现阳性的患者的临床发现。除了进行泛微孢子虫和属特异性聚合酶链反应检测外，还通过显微镜检查检测了痰液和粪便样本。9 例肺癌患者的微孢子虫检测结果为阳性（9.2%），明显高于健康个体（P=0.008），且大多数患者有临床发现。在这些阳性患者中，聚合酶链反应显示 7 例患者的痰液样本、1 例患者的粪便样本以及 1 例患者的痰液和粪便样本中存在微孢子虫。在 87.5%（7/8）的阳性痰液样本中，鉴定出的主要病原体为兔脑炎微孢子虫。微孢子虫感染与癌症的晚期阶段显著相关。然而，在对照组中，在一名无临床症状的个体的粪便样本中检测到了肠脑炎微孢子虫。微孢子虫，特别是兔脑炎微孢子虫，应被视为癌症患者肠道和呼吸道感染的原因，并且应在这些患者出现肺部症状时对其呼吸道样本进行筛查。
