New Highly Divergent rRNA Sequence among Biodiverse Genotypes ofEnterocytozoon bieneusiStrains Isolated from Humans in Gabon and Cameroon

Abstract

Intestinal microsporidiosis due to Enterocytozoon bieneusi is a leading cause of chronic diarrhea in severely immunocompromised human immunodeficiency virus (HIV)-positive patients. It may be a public health problem in Africa due to the magnitude of the HIV pandemic and to poor sanitary conditions. We designed two prevalence studies of E. bieneusi in Central Africa, the first with HIV-positive patients from an urban setting in Gabon and the second with a nonselected rural population in Cameroon. Stool samples were analyzed by an immunofluorescence antibody test and PCR. Twenty-five out of 822 HIV-positive patients from Gabon and 22 out of 758 villagers from Cameroon were found to be positive for E. bieneusi. The prevalence rates of the two studies were surprisingly similar (3.0% and 2.9%). Genotypic analysis of the internal transcribed spacer region of the rRNA gene showed a high degree of diversity in samples from both countries. In Gabon, 15 isolates showed seven different genotypes: the previously reported genotypes A, D, and K along with four new genotypes, referred to as CAF1, CAF2, CAF3, and CAF4. In Cameroon, five genotypes were found in 20 isolates: the known genotypes A, B, D, and K and the new genotype CAF4. Genotypes A and CAF4 predominated in Cameroon, whereas K, CAF4, and CAF1 were more frequent in Gabon, suggesting that different genotypes present differing risks of infection associated with immune status and living conditions. Phylogenetic analysis of the new genotype CAF4, identified in both HIV-negative and HIV-positive subjects, indicates that it represents a highly divergent strain.

Molecular Epidemiologic Characterization of Enterocytozoon bieneusi in HIV-Infected Persons in Benin City, Nigeria

“…Of the six known genotypes, three have been reported from studies in other African countries. 20,21 Genotypes A (28.5%) and CAF2 (2.5%) were slightly lower in prevalence than the genotypes reported in Cameroon (40.0%) 18 and Gabon (6.6%), 19 whereas genotype D (40.2%) had a higher prevalence than the genotype (15.0%) observed in Cameroon. 18 Both genotypes D and IV have a broad host and geographic range.…”

“…Genotypes A, D, and IV were found mostly in married patients (18, 27, and 13 patients, respectively), traders (13,16, and 7 patients, respectively), patients with weight loss (17, 28, and 9 patients, respectively), patients using boreholes as a source of water (20,26, and 11 patients, respectively), and patients with flush-type toilets (18, 25, and 7 patients, respectively). Phylogenetically, most of the study participants were infected with genotypes belonging to the initially described human pathogenic group 10 or the recently renamed Group 1 ( Figure 1).…”

“…Previously, the only E. bieneusi genotype in humans outside Group 1 was CAF4, which was found in a few cases in Gabon and Cameroon. 20 Thus, unusual E. bieneusi genotypes can be human pathogens in some areas. Additional studies are required to identify the source of these and other genotypes of E. bieneusi in HIV-infected patients in Nigeria.…”

Frequency of Microsporidial Infection in Immunocompromised Patients with Staining and Molecular Methods Based on Internal Transcribed Spacer Region Gene in Two Cities of Southwest Iran during 2013-2014

“…By spread of HAART in the developed countries, prevalence of the opportunistic infections including microsporidiosis dramatically declined due to improvements inimmune system 2,5,27 ,while opportunistic infections such as microsporidia remain problematic in developing countries where HAART is not easily available for HIV + patients 28,29 . In Ahvaz, detection of microsporidia is not routinely carried out in hospital or medical diagnostic centers; therefore, little is known about intestinal microsporidiosis in HIV + and cancer patients.…”

Mikrosporidialar ve Mikrosporidiyozis

“…Bu genotipler içersinde genotip A ve B genellikle antroponotik potansiyele sahipken, genotip K (aynı zamanda genotip IV, BEB5 ve Peru2), D ve E zoonotik potansiyele sahiptir. Genotiplendirme analizleri yapılarak zoonotik ve antroponotik geçişin gösterilme-si, enfeksiyonun sıklıkla görüldüğü bölgelerde kontrol stratejilerinin belirlenmesi açısından büyük önem arzetmektedir (45,46). Tanıda kullanılan tür-spesifik primer çiftleri Tablo 2'de sunulmuş-tur (46)(47)(48)(49)(50)(51)(52)(53)(54)(55).…”