Department of Infectious Disease, Istituto Superiore di Sanità, Rome, Italy.
Department of Medicine, Faculty of Medicine, Siriraj Hospital, Mahidol University, Bangkok, Thailand.
Parasit Vectors. 2019 Mar 12;12(1):91. doi: 10.1186/s13071-019-3348-4.
Opportunistic infections represent a serious health problem for HIV-infected people. Among enteric infections, cryptosporidiosis, a severe and life-threatening diarrheal disease, is of particular importance in low economic settings where access to anti-retroviral therapy is limited. Understanding transmission routes is crucial in establishing preventive measures, and requires the use of informative genotyping methods. In this study, we performed a retrospective analysis of Cryptosporidium species in 166 stool samples collected from 155 HIV-infected patients during 1999-2004 at the Siriraj Hospital in Bangkok, Thailand.
Microscopic examination of stools identified 104 of the 155 patients as positive for Cryptosporidium. Other common pathogens identified were microsporidia, Isospora, Giardia, Strongyloides and Opisthorchis. All samples were tested by amplification of a fragment of the 18S rDNA locus, and sequencing showed the presence of Cryptosporidium hominis (n = 42), C. meleagridis (n = 20), C. canis (n = 12), C. felis (n = 7), C. suis (n = 6) and C. parvum (n = 5). Genotyping at the glycoprotein 60 (gp60) locus revealed substantial variability in isolates of C. hominis and C. meleagridis. Among C. hominis isolates, subtype IeA11G3T3 was the most prevalent, but allelic family Id was the more diverse with four subtypes described, two of which were identified for the first time. Among C. meleagridis isolates, seven subtypes, two of which were new, were found in the allelic family IIIb, along with new subtypes in allelic families IIIe and IIIg. In the four C. parvum isolates, subtype IIoA16G1, a rare subtype previously reported in a Swedish patient who had traveled to Thailand, was identified.
This study confirms the high susceptibility of HIV-infected individuals to infection with different Cryptosporidium species and subtypes, and further stresses the importance of surveillance for opportunistic intestinal protozoans.
机会性感染是 HIV 感染者面临的严重健康问题。在肠道感染中，隐孢子虫病是一种严重且危及生命的腹泻病，在获得抗逆转录病毒治疗机会有限的低经济环境中尤其重要。了解传播途径对于制定预防措施至关重要，这需要使用信息丰富的基因分型方法。在这项研究中，我们对 1999 年至 2004 年间在泰国曼谷的 Siriraj 医院采集的 166 份来自 155 名 HIV 感染者的粪便样本中的隐孢子虫物种进行了回顾性分析。
粪便镜检发现 155 名患者中有 104 名为隐孢子虫阳性。其他常见病原体包括微孢子虫、等孢子虫、贾第鞭毛虫、类圆线虫和华支睾吸虫。所有样本均通过扩增 18S rDNA 基因座片段进行检测，测序结果显示存在隐孢子虫人型（n=42）、隐孢子虫牛型（n=20）、隐孢子虫犬型（n=12）、隐孢子虫猫型（n=7）、隐孢子虫猪型（n=6）和隐孢子虫微小型（n=5）。在糖蛋白 60（gp60）基因座进行基因分型显示，人型隐孢子虫和牛型隐孢子虫分离株存在很大的变异性。人型隐孢子虫分离株中，IeA11G3T3 亚型最为常见，但等位基因家族 Id 更为多样化，共描述了 4 种亚型，其中 2 种为首次发现。牛型隐孢子虫分离株中，在等位基因家族 IIIb 中发现了 7 种亚型，其中 2 种为新亚型，同时在等位基因家族 IIIe 和 IIIg 中也发现了新亚型。在 4 株微小隐孢子虫分离株中，鉴定出了以前在一名曾前往泰国的瑞典旅行者中报道过的罕见亚型 IIoA16G1。
本研究证实 HIV 感染者易感染不同的隐孢子虫物种和亚型，进一步强调了对机会性肠道原生动物进行监测的重要性。
