Unusual dominant genotype NIA1 of Enterocytozoon bieneusi in children in Southern Xinjiang, China

First molecular detection and characterization of Enterocytozoon bieneusi different genotypes in human patients from Italy

Enterocytozoon bieneusi is one of the 17 microsporidian species pathogenic to humans in low and high-income countries, inducing both symptomatic and asymptomatic intestinal infections, independently of the immunological condition of the infected individual. Faecal-oral transmission occurs in a broad hosts range, including several animal species, but the parasite's zoonotic potential remains still unclear. Few studies are available in Italy regarding E. bieneusi presence in humans and no data on its genetic variability are so far reported. In this investigation, through the ITSr RNA sequences analysis, we provided the first E. bieneusi molecular characterization from symptomatic patients in Italy. Faecal samples from 410 patients sent for routine analyses to the Unit of Parasitology, Policlinico Tor Vergata, Rome, and resulted positive for E. bieneusi to a cartridge-based molecular test for qualitative detection (Novodiag® Stool Parasites assay), were collected. DNA was extracted, endpoint PCR performed and then sequences obtained for 3/410 patients (0.7 %). Genotype A (N = 1), genotype C (N = 1) and genotype K (N = 1) were identified, all belonging to phylogenetic Group 1. One patient (identified as genotype A) showed positivity to the same genotype previously characterized after a two-month period. Additional investigations are required, within a One Health framework, to review the importance of a zoonotic potential linked to E. bieneusi in human populations, animals and environmental reservoirs worldwide.

Global prevalence and risk factors of Enterocytozoon bieneusi infection in humans: a systematic review and meta-analysis

Enterocytozoon bieneusi is one of the most important zoonotic pathogens. In this study, we present a systematic review and meta-analysis of the prevalence of human E. bieneusi infection in endemic regions and analyze the various potential risk factors. A total of 75 studies were included. Among 31,644 individuals tested, 2,291 (6.59%) were E. bieneusi-positive. The highest prevalence of E. bieneusi in the male population was 5.50%. The prevalence of E. bieneusi in different age groups was varied, with 10.97% in teenagers. The prevalence of E. bieneusi in asymptomatic patients (6.49%) is significantly lower than that in HIV-infected patients (11.49%), and in patients with diarrheal symptoms (16.45%). Rural areas had a higher rate (7.58%) than urban ones. The prevalence of E. bieneusi in humans was the highest (6.42%) at altitudes <10 m. Moreover, the temperate zone marine climate (13.55%) had the highest prevalence. A total of 69 genotypes of E. bieneusi have been found in humans. This is the first global study regarding E. bieneusi prevalence in humans. Not only people with low immunity (such as the elderly, children, people with HIV, etc.), but also people in Europe in temperate marine climates should exercise caution to prevent infection with E. bieneusi during contact process with animals.

Molecular characterization of Enterocytozoon bieneusi genotypes in wild Altai marmot (Marmota baibacina) in Xinjiang, China: host specificity and adaptation

Enterocytozoon bieneusi is responsible for opportunistic infections leading to gastrointestinal diseases in humans and animals worldwide. A total of 334 fresh fecal samples were collected from wild Altai marmots (Marmota baibacina) in Xinjiang, China, and E. bieneusi was screened via PCR amplification of the internal transcribed spacer (ITS) region of the small submit ribosomal RNA (SSU rRNA). The results indicated that 22.8% (76/334) of the wild Altai marmot fecal samples were positive for E. bieneusi, and the highest positive rate was detected in Akqi (51.9%, 27/52), with a significant difference from other sampling sites (p < 0.01). Four known genotypes (BEB6, CHG3, GX2, and YAK1) and three novel genotypes (XJHT2 to XJHT4) were identified in the present study. Genotype XJHT3 was dominant and detected in 48 fecal samples. In the phylogenetic analysis, the novel genotypes XJHT2 and XJHT3 were clustered in Group 1 together with the known genotype YAK1, while genotypes CHG3 and BEB6 were clustered in Group 2. The novel genotype XJHT4 was clustered together with other rodent-derived genotypes and generated a novel Group 14. These data confirmed the host specificity and adaptation of E. bieneusi in rodents. These findings enrich our understanding of the prevalence and genetic diversity of E. bieneusi in wild Altai marmots in Xinjiang, China.

Prevalence and associated risk factors of intestinal parasites among schoolchildren in Ecuador, with emphasis on the molecular diversity of Giardia duodenalis, Blastocystis sp. and Enterocytozoon bieneusi

BACKGROUND

Intestinal helminths, including Soil-Transmitted Helminth (STH), and Gastrointestinal Protist (GP) infections are major contributors to the global burden of disease, particularly in low-income countries such Ecuador. Their epidemiology in these settings is largely unknown.

METHODOLOGY

This prospective cross-sectional study investigates the carriage of intestinal helminths, including STH, and GP in asymptomatic schoolchildren (3-11 years) in the Chimborazo and Guayas provinces, Ecuador. Single stool samples (n = 372) and epidemiological questionnaires on demographics and potential risk factors were collected from participating schoolchildren. Conventional microscopy examination was used as screening method, and molecular (PCR and Sanger sequencing) assays were used to further investigate the epidemiology of some GP. A multivariate logistic regression analysis was used to evaluate the strength of the association of suspected risk factors with the presence of helminths and GP.

PRINCIPAL FINDINGS

At least one intestinal parasite species was observed by microscopy in 63.2% (235/372) of the participating schoolchildren. Enterobius vermicularis (16.7%, 62/372; 95% CI: 13.0-20.9) and Blastocystis sp. (39.2%, 146/372; 95% CI: 34.2-44.2) were the most prevalent among helminths and GP, respectively. Assemblages A (50.0%), B (37.5%) and A+B (12.5%) were detected within Giardia duodenalis and ST3 (28.6%), ST1 and ST2 (26.2% each), and ST4 (14.3%) within Blastocystis sp. Three genotypes, two known (A: 66.7%; KB-1: 16.7%) and a novel (HhEcEb1, 16.7%) were identified within Enterocytozoon bieneusi. Municipality of origin, household overcrowding, and poor sanitation and personal hygiene habits were risk factors for childhood intestinal parasites colonization.

CONCLUSIONS/SIGNIFICANCE

Despite massive government drug administration programs, STH and GP infection remain a public health concern in paediatric populations living in poor-resource settings. Molecular analytical methods are required to better understand the epidemiology of these intestinal parasites. This study provides novel information on the occurrence of Blastocystis sp. and E. bieneusi genetic variants circulating in Ecuadorian human populations.

Molecular identification and genetic characteristics of Cryptosporidium spp., Giardia duodenalis, and Enterocytozoon bieneusi in human immunodeficiency virus/acquired immunodeficiency syndrome patients in Shanghai, China

BACKGROUND

Opportunistic infections are a ubiquitous complication in human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) patients. Cryptosporidium spp., Giardia duodenalis, and Enterocytozoon bieneusi are common opportunistic intestinal pathogens in humans. In China, despite the number of HIV/AIDS patients being extremely large, only a few studies have investigated opportunistic infections caused by intestinal pathogens in this patient population. The aims of this study were to elucidate the occurrence and genetic characteristics of Cryptosporidium spp., G. duodenalis, and E. bieneusi in HIV/AIDS patients.

METHODS

We collected fecal specimens from 155 HIV/AIDS patients (one from each patient). All of the specimens were examined for the presence of the pathogens by genotyping using polymerase chain reaction and sequencing of the small subunit ribosomal RNA gene for Cryptosporidium spp.; the triosephosphate isomerase, β-giardin and glutamate dehydrogenase genes for G. duodenalis; and the internal transcribed spacer region of the rRNA gene for E. bieneusi. The Cryptosporidium-positive specimens were further subtyped by polymerase chain reacion and sequencing of the 60-kDa glycoprotein gene.

RESULTS

Six (3.9%), three (1.9%), and eight (5.2%) HIV/AIDS patients were positive for Cryptosporidium spp., G. duodenalis, and E. bieneusi, respectively. No statistical differences were observed in occurrence rate between the groups by gender, clinical symptom (diarrhea), and CD4⁺ cell count. Four Cryptosporidium species were identified: Cryptosporidium hominis (n = 2), Cryptosporidium parvum (n = 1), Cryptosporidium meleagridis (n = 1), and Cryptosporidium andersoni (n = 2). Furthermore, two C. hominis subtypes (IeA12G3T3 and IaA28R4) were detected. Three G. duodenalis-positive specimens were successfully amplified and sequenced at the triosephosphate isomerase and β-giardin loci, which led to the identification of assemblages C and B, respectively. Seven genotypes (D, Type IV, EbpC, Peru11, EbpD, A, and I) were identified in E. bieneusi-positive specimens.

CONCLUSIONS

Our findings should increase awareness of AIDS-related opportunistic intestinal pathogens, and indicate the need for routine examination in clinical practice for the detection of Cryptosporidium spp., G. duodenalis, and E. bieneusi. Homology analyses of the three intestinal pathogens at the nucleotide and/or amino acid levels indicated their zoonotic potential.

First report on occurrence and genotypes of Enterocytozoon bieneusi, Cryptosporidium spp. and Cyclospora cayetanensis from diarrheal outpatients in Ningbo, Southeast China

Enterocytozoon bieneusi, Cryptosporidium spp. and Cyclospora cayetanensis are three important zoonotic pathogens which were a major cause of foodborne or waterborne intestinal diseases in humans and animals. However, very little data about occurrence and genotypes of the three parasites in Ningbo in the south wing of the Yangtze River Delta, China, which is important for a tourist city. In the present study, molecular characterization of E. bieneusi, C. cayetanensis and Cryptosporidium spp. in fecal samples from 489 diarrheal outpatients were carried out. As a result, a total of 35 (7.16%, 35/489) and three (0.61%, 3/489) samples were positive for E. bieneusi and C. cayetanensis respectively. No Cryptosporidium-positive sample or mixed-infections were detected. Four known E. bieneusi genotypes (Type IV, D, I and CHN4) and 8 novel genotypes (NBH1-NBH8) were identified with type IV was the dominant genotype (n = 14), followed by genotypes D (n = 5), NBH8 (n = 5) and NBH7 (n = 3). The remaining genotypes were found in one sample each, and these genotypes were belonged to the previously described high-potential zoonotic group 1. One novel sequence named NBC315, and the other two sequences (NBC30 and NBC370) identical with the reported sequence were detected. Therefore, the existence and importance of zoonotic potential of E. bieneusi and C. cayetanensis in diarrheal outpatients in Ningbo indicates the public health threats, and more investigations should be carried out in human populations, animals and other environmental sources from the One Health perspective.

Enterocytozoon bieneusi in patients with diarrhea and in animals in the northeastern Chinese city of Yichun: genotyping and assessment of potential zoonotic transmission

Enterocytozoon bieneusi is a common microsporidia species in humans and animals. Due to lack of effective vaccines and drugs, understanding of its epidemiological status and characteristics in different hosts is an important step in controlling the infection. The present study aimed at determining the prevalence of E. bieneusi in humans with diarrhea and animals in Yichun, in northeastern China, and assessing the epidemiological role of animals in the transmission of microsporidiosis. A total of 540 fecal samples were collected from diarrheal patients (n = 222) and 11 animal species (n = 318). Enterocytozoon bieneusi was identified and genotyped by polymerase chain reaction (PCR) and sequencing of the internal transcribed spacer (ITS) region of the rRNA gene. Enterocytozoon bieneusi was detected in 1.4% (3/222) of diarrheal patients, and genotype D and novel genotypes YCHH1 and YCHH2 were identified. Enterocytozoon bieneusi was detected in wild boars (7.7%), sika deer (8.2%), dogs (3.2%), and ostriches (10.7%), and genotypes D, Type IV, Peru6, BEB6 and novel genotypes YCHA1, YCHA2 and YCHA3 were identified. Genotypes YCHH1, YCHH2 and YCHA1 were phylogenetically assigned to group 1, while YCHA2 and YCHA3 to groups 2 and 11, respectively. The finding of genotype D in humans and animals, and the identification of zoonotic genotypes Peru6, Type IV, BEB6 in animal-derived E. bieneusi isolates indicate the potential of zoonotic transmission of microsporidiosis in the investigated area. The observation of the three novel genotypes in group 1 indicates their zoonotic potential.

Molecular prevalence and genetic diversity analysis of Enterocytozoon bieneusi in humans in Hainan Province, China: High diversity and unique endemic genetic characteristics

Enterocytozoon bieneusi is a zoonotic pathogen commonly found in humans and animals all over the world. Here, we investigated the occurrence and genotype constitute of E. bieneusi among the individuals from Haikou city of Hainan, China. A total of 1,264 fecal samples of humans were collected, including 628 samples from patients with diarrhea (325 adults and 303 children) and 636 samples from the asymptomatic population (383 college students and 253 kindergarten children). E. bieneusi was detected using nested polymerase chain reaction (PCR) amplification of the internal transcribed spacer (ITS) region. A phylogenetic tree was constructed using a neighbor-joining tree construction method. The overall prevalence of E. bieneusi was 3.7% (47/1,264), while it was 5.6% in the patients with diarrhea (5.8% in adults and 5.3% in children) and 1.9% in the asymptomatic population (2.9% in college students and 0.4% in kindergarten children). The prevalence of E. bieneusi in humans with diarrhea was significantly higher than that in the asymptomatic population (χ² = 36.9; P < 0.05). A total of 28 genotypes were identified, including ten known genotypes: CHG2 (n = 3), CHG3 (n = 5), CHG5 (n = 10), CM21 (n = 1), EbpA (n = 1), EbpC (n = 1), PigEBITS4 (n = 1), PigEBITS7 (n = 1), SHR1 (n = 4), Type IV (n = 2), and 18 novel genotypes (HNH-1 to HNH-18; one each). All these genotypes were categorized into three groups, including group 1 (n = 6), group 2 (n = 14), and group 13 (n = 8). This was the first study on the identification of E. bieneusi among humans in Hainan, China. The correlation between E. bieneusi infection and diarrhea was observed. The high diversity and distinctive distribution of E. bieneusi genotypes found in this study reflected the unique epidemic genetic characteristics of E. bieneusi in humans living in Hainan.

Prevalence and new genotypes of Enterocytozoon bieneusi in wild rhesus macaque (Macaca mulatta) in China: A zoonotic concern

Enterocytozoon bieneusi is a zoonotic pathogen with a wide range of animal host. There are only few reports of E. bieneusi infection in wild Chinese rhesus macaques. Here, we determined the prevalence of E. bieneusi in nine wild rhesus macaque populations and assessed their zoonotic potential by performed genotype of ITS gene. A total of 324 fecal samples of rhesus macaque were collected in nine geographical populations from five Chinese provinces (Sichuan, Chongqing, Qinghai, Tibet and Hainan). 38 samples (11.7%) were found to be infected with E. bieneusi, and 11 genotypes were identified including three known genotypes (D, EbpC and SCC-2) and eight novel genotypes named Mul6∼13. Genotype D (63.2%) was the most prevalent, being observed in seven populations except XZ-2 and QH, and other genotypes were identified only in a single area. According to the phylogenetic analysis, Mul6∼9, Mul11∼13 and zoonotic genotype D were clustered into Group 1, indicating that these genotypes may be potentially zoonotic. Among nine populations, population SC-3 had the highest infection rate (26.3%), and the lowest was the wild QH population without infection, but the difference of infection rate among the nine populations is not significant. It is concluded that, rhesus macaque populations are generally infected E. bieneusi in many areas of China, and there may be a risk of cross infection with E. bieneusi in some areas found having zoonotic genotypes, and these areas should be paid more attention to prevent.

•

Nine geographical populations (3 semi-wild and 6 wild) from five Chinese provinces (Sichuan, Chongqing, Qinghai, Tibet and Hainan).

•

11 genotypes of Enterocytozoon bieneusi were identified.

•

Three known genotypes (D, EbpC and SCC-2) and eight novel genotypes (Mul6∼13).

Prevalence and genetic characterization of Enterocytozoon bieneusi in children in Northeast Egypt

Enterocytozoon bieneusi is the most common microsporidia in humans worldwide, in addition to infecting a wide range of animals. However, there is limited information about this pathogen in children in Egypt. Here, we carried out a molecular epidemiological study of E. bieneusi in child care centers in three provinces in Egypt. Altogether, 585 fresh fecal samples were collected from children attending 18 child care centers in El-Dakahlia, El-Gharbia, and Damietta provinces in Northeast Egypt during March 2015 to April 2016. PCR and sequence analyses of the ribosomal internal transcribed spacer (ITS) were used to detect and genotype E. bieneusi. Twenty-seven fecal samples (4.6%, 27/585) were positive for E. bieneusi. Five genotypes were identified, including type IV (n = 13), Peru8 (n = 9), Peru6 (n = 2), Peru11 (n = 2), and D (n = 1). Phylogenetic analysis indicated that the five genotypes of E. bieneusi detected in this study were clustered into zoonotic group 1. These data provide important information on the prevalence and genetic diversity of E. bieneusi in children in this country. Further epidemiological studies should be conducted to elucidate the role of zoonotic transmission in human E. bieneusi infections.

First molecular characterization of Enterocytozoon bieneusi in children and calves in Bangladesh

Enterocytozoon bieneusi is a widespread opportunistic pathogen found in humans and domestic animals, including cattle that poses a public health risk. This study was performed to evaluate the prevalence, genotypic diversity, and zoonotic potential of E. bieneusi among children and calves in Bangladesh. A total of 998 fecal samples were collected from children (n = 299) and calves (n = 699) and screened by nested PCR and sequencing of the ribosomal internal transcribed spacer (ITS). The overall prevalence of E. bieneusi infection was 6.4% in children and 7.9% in calves. ITS sequence analysis of 74 isolates revealed 10 genotypes, including eight known genotypes (A, D, Type IV, PigEBITS7, I, J, BEB4, and BEB6) and two new genotypes (BANEB1 and BANEB3). Specifically, genotypes A, D, Type IV, PigEBITS7, BANEB1, and BANEB3, and genotypes D, PigEBITS7, I, J, BEB4, and BEB6 were detected in children and calves, respectively. Among them, genotypes D and I were dominant genotypes in children and calves, respectively. The genotypes D and PigEBITS7 were found in both children and calves, with PigEBITS7 being observed for the first time in calves. In phylogenetic analysis, six genotypes (A, D, Type IV, PigEBITS7, BANEB1, and BANEB3), detected in 39.2% of the isolates, belonged to zoonotic Group 1. The remaining four genotypes I, J, BEB4, and BEB6 were clustered in Group 2 and are common members of the group with zoonotic potential. To the best of our knowledge, this study provides the first report of E. bieneusi infection in calves in Bangladesh and also the first molecular characterization of the parasite in children and calves in this country. Two new genotypes in children have been found, which is noteworthy. Furthermore, the presence of zoonotic genotypes indicates that cattle may serve as reservoirs for E. bieneusi, which can be a source of human microsporidiosis.

Occurrence and potentially zoonotic genotypes of Enterocytozoon bieneusi in wild rhesus macaques (Macaca mulatta) living in Nanwan Monkey Island, Hainan, China: a public health concern

BACKGROUND

Enterocytozoon bieneusi, a microsporidian species, is a zoonotic pathogen found in both humans and animals. Here, we determined the prevalence, explored the different genotypes of E. bieneusi in wild rhesus macaques (Macaca mulatta) (Hainan Island of China), and assessed their zoonotic potential.

METHODS

We collected 173 fecal specimens from wild rhesus macaques living in Nanwan Monkey Island, Hainan, China. Subsequently, we identified and genotyped E. bieneusi using nested PCR analysis amplification of the internal transcribed spacer region (ITS) of the rRNA gene. Lastly, a neighbor-joining tree was built based on gene sequences from the ITS region of E. bieneusi.

RESULTS

Of the 173 specimens from wild rhesus macaques, 26 (15%) were infected with E. bieneusi. We identified six genotypes of E. bieneusi, of which five were known: PigEBITS7 (n = 20), D (n = 2), Type IV (n = 1), Peru6 (n = 1), Henan-III (n = 1), and a novel genotype: HNM-IX (n = 1). From the phylogenetic analysis, the six genotypes identified here were all clustered into zoonotic group 1.

CONCLUSION

This study is the first report to detect E. bieneusi infection in wild rhesus macaques from Hainan, China. Human-pathogenic genotypes D, Henan-III, Peru6, PigEbITS7, and Type IV in the wild rhesus macaques support these animals infected with E. bieneusi have a public health significance.

Prevalence and Phylogenetic Analysis of Microsporidium Enterocytozoon bieneusi in Diarrheal Patients

Enterocytozoon bieneusi can cause severe diarrhea in children and adults. However, in China, there are scant studies on E. bieneusi in diarrheal children and adults, with the exception of prevalence and genotyping data in a small number of cities including Hubei, Shanghai, and Heilongjiang. In this study, 196 fecal samples (n = 132 in Chongqing, n = 44 in Shandong, n = 20 in Hubei) were collected, including 91 from children and 105 from adults. Through microscopic examination, 19 positive samples (11 from children and 8 from adults) were detected. Using PCR examination, the internal transcriptional spacer (ITS) region was utilized by nested PCR to detect and characterize E. bieneusi. Twenty positive samples were detected, including 14 from children (≤11 years of age) and 6 from adults. According to the sequence analysis of ITS data, one known zoonotic (D) and seven novel (CQH5-11) genotypes were identified. This is the first molecular epidemiological study of E. bieneusi in diarrheal patients in different regions of China. Therefore, this study can provide useful information for the molecular epidemiology and control of E. bieneusi infection in humans in the future.