Messaoud Mariem, Abbes Salma, Gnaien Mayssa, Rebai Yasmine, Kallel Aicha, Jemel Sana, Cherif Ghaya, Skhairia Mohamed Amine, Marouen Sonia, Fakhfekh Najla, Mardassi Helmi, Belhadj Slaheddine, Znaidi Sadri, Kallel Kalthoum
Laboratoire de Parasitologie et Mycologie, UR17SP03, La Rabta Hospital, Tunis 1007, Tunisia.
Institut Pasteur de Tunis, University of Tunis El Manar, Laboratoire de Microbiologie Moléculaire, Vaccinologie et Développement Biotechnologique, Tunis 1002, Tunisia.
J Fungi (Basel). 2021 Feb 24;7(3):161. doi: 10.3390/jof7030161.
Microsporidiosis is an emerging opportunistic infection causing severe digestive disorders in immunocompromised patients. The aim of this study was to investigate the prevalence of intestinal microsporidia carriage among immunocompromised patients hospitalized at a major hospital complex in the Tunis capital area, Tunisia (North Africa), and perform molecular epidemiology and population structure analyses of , which is an emerging fungal pathogen. We screened 250 stool samples for the presence of intestinal microsporidia from 171 patients, including 81 organ transplant recipients, 73 Human Immunodeficiency Virus (HIV)-positive patients, and 17 patients with unspecified immunodeficiency. Using a nested PCR-based diagnostic approach for the detection of spp., we identified 18 microsporidia-positive patients out of 171 (10.5%), among which 17 were infected with . Microsporidia-positive cases displayed chronic diarrhea (17 out of 18), which was associated more with HIV rather than with immunosuppression other than HIV (12 out of 73 versus 6 out of 98, respectively, = 0.02) and correlated with extended hospital stays compared to microsporidia-negative cases (60 versus 19 days on average, respectively; = 0.001). Strikingly, internal transcribed spacer (ITS)-based genotyping of strains revealed high-frequency occurrence of ITS sequences that were identical ( = 10) or similar (with one single polymorphic site, = 3) to rare genotype WL12. Minimum-spanning tree analyses segregated the 17 infection cases into four distinct genotypic clusters and confirmed the high prevalence of genotype WL12 in our patient population. Phylogenetic analyses allowed the mapping of all 17 strains to zoonotic group 1 (subgroups 1a and 1b/1c), indicating loose host specificity and raising public health concern. Our study suggests a probable common source of genotype WL12 transmission and prompts the implementation of a wider epidemiological investigation.
微孢子虫病是一种新出现的机会性感染，可导致免疫功能低下患者出现严重的消化系统紊乱。本研究的目的是调查在突尼斯首都地区（北非）一家大型医院综合体住院的免疫功能低下患者中肠道微孢子虫携带情况，并对一种新出现的真菌病原体进行分子流行病学和种群结构分析。我们对171名患者的250份粪便样本进行筛查，以检测肠道微孢子虫的存在，其中包括81名器官移植受者、73名人类免疫缺陷病毒（HIV）阳性患者和17名免疫缺陷情况未明确的患者。使用基于巢式PCR的诊断方法检测微孢子虫属物种，我们在171名患者中鉴定出18名微孢子虫阳性患者（10.5%），其中17名感染了[具体微孢子虫物种名称未给出]。微孢子虫阳性病例表现为慢性腹泻（18例中有17例），这与HIV感染的关联度高于HIV以外免疫抑制情况（分别为73例中的12例和98例中的6例，P = 0.02），并且与微孢子虫阴性病例相比，住院时间延长相关（平均分别为60天和19天；P = 0.001）。引人注目的是，基于内部转录间隔区（ITS）的[具体微孢子虫物种名称未给出]菌株基因分型显示，ITS序列高频出现与罕见基因型WL12相同（n = 10）或相似（有一个单核苷酸多态性位点，n = 3）的情况。最小生成树分析将这17例[具体微孢子虫物种名称未给出]感染病例分为四个不同的基因型簇，并证实了基因型WL12在我们的患者群体中具有高流行率。系统发育分析将所有17株[具体微孢子虫物种名称未给出]菌株定位到人畜共患的第1组（亚组1a和1b/1c），表明宿主特异性较弱，引发了公共卫生关注。我们的研究表明[具体微孢子虫物种名称未给出]基因型WL12传播可能存在共同来源，并促使开展更广泛的流行病学调查。
