Identification and genotyping of Enterocytozoon bieneusi among human immunodeficiency virus infected patients

Prevalence and Individualized Risk Factors of E. bieneusi and E. intestinalis Infections Among People Living with HIV (PLHIV) with Diarrhea in Ecuador: Insights from a Single-Center Cross-Sectional Study

Background: Microsporidia, particularly E. bieneusi and E. intestinalis, are emerging opportunistic pathogens that pose significant health risks to immunocompromised individuals, especially people living with HIV (PLHIV). Despite the global recognition of microsporidia's impact, there has been limited research on their prevalence and associated risk factors in Ecuador. This study aimed to investigate the prevalence and identify risk factors associated with microsporidia infections among PLHIV with diarrhea in Ecuador. Methods: A cross-sectional study was conducted at the José Daniel Rodríguez Infectious Hospital in Guayaquil, Ecuador, between April 2021 and May 2022. A total of 85 PLHIV with diarrhea were included in the analysis. Fecal samples were tested for microsporidia using fast-hot Gram chromotrope staining, immunofluorescence microscopy, and transmission electron microscopy. Logistic regression was performed to assess the association between demographic, clinical, and behavioral factors and microsporidia infection. Results: The prevalence of microsporidia infections among the study population was 18.8%. Logistic regression analysis identified significant associations with age ≥ 60 years (OR = 19.169, p = 0.036), female sex (OR = 10.491, p = 0.028), and non-adherence to antiretroviral therapy (OR = 8.466, p = 0.077). Marginally significant associations were observed for substance use (OR = 0.262, p = 0.094) and high/very high HIV viral load (≥10,000 copies/mL, OR = 0.457, p = 0.094). CD4 count and marital status showed descriptive trends but were not statistically significant. Conclusions: This study highlights the burden of microsporidia infections among PLHIV in Ecuador and underscores the need for targeted public health interventions. Strategies should prioritize older individuals, females, and those with poor ART adherence to reduce infection risk. Future research is needed to explore additional risk factors and refine precision medicine approaches for this population.

Meta-analysis of the global prevalence and risk factors of Enterocytozoon bieneusi infection in pigs from 1999 to 2021

Enterocytozoon bieneusi (E. bieneusi), which is one of the most common microsporidia, has been identified as an important obligate intracellular pathogen that commonly colonizes in a variety of animal species and humans worldwide, including humans. In this study, the statistical analyses of E. bieneusi infection and prevalence were performed to clarify the relationship between different genotypes in different countries. The databases Chinese National Knowledge Infrastructure (CNKI), VIP Chinese Journal Database, Wanfang Data, PubMed, Web of Science and ScienceDirect were used for data collection. The research data were subjected to subgroup, univariate regression, and correlation, to reveal factors related to the high prevalence of E. bieneusi. A total of, 34 of the 498 articles published before April 2022 met the inclusion criteria. The global prevalence of E. bieneusi in pigs was 37.69% (5175/12672). The prevalence of E. bieneusi in nursery pigs was 58.87% (588/946). In developing countries and Asia, the highest prevalence of E. bieneusi in pigs were 37.62% (4752/11645) and 40.14% (4715/11345), respectively. Moreover, humans and pigs have been found to be infected with the same genotype of E. bieneusi in some cases, as evidenced by the consolidation of genotype information. The results showed that pigs are susceptible to E. bieneusi during the nursery period. The prevalence of E. bieneusi is high in developing countries, and its genotype prevalence varies in each country. Thus, it is essential to strengthen the health inspection of vulnerable groups and customs quarantine inspection.

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.

Microscopic and Molecular Investigation of Intestinal Microsporidia in HIV + /AIDS and Cancer Patients Undergoing Chemotherapy in Mazandaran Province, North of Iran

BACKGROUND

The aim of this study was to identify Enterocytozoon bieneusi and Encephalitozoon spp. in fecal samples of HIV + /AIDS and cancer patients undergoing chemotherapy, and comparing the results to healthy individuals in Mazandaran province, north of Iran.

METHODS

Stool samples were collected from 50 HIV + /AIDS patients, 50 cancer patients, and 50 healthy samples referred to medical centers in north of Iran. Stool samples were kept in 2.5% potassium dichromate at 4 °C, and stained by modified trichrome for light microscopy examination. The multiplex/nested-PCR targeted the small subunit ribosomal RNA (SSU rRNA) gene. To characterize genotypes, the nested PCR products sequenced by Bioneer Company and was subjected to phylogenetic analyses.

RESULTS

Ten of 50 samples (20%) of HIV + /AIDS patients, 5 of 50 samples (10%) of cancer patients, and 1 of healthy individuals (2%) were microscopically positive. From 50 HIV + / AIDS patients, E. bieneusi and Encephalitozoon spp. were detected in 10 (20%) and 6 (12%) cases, respectively. Furthermore, among cancer patients, 7 (14%) and 2 (4%) cases were E. bieneusi and Encephalitozoon spp., respectively. Out of 50 samples of healthy individuals, only 3 (6%) cases of E. bieneusi were observed. The genotypes D and M were detected among positive samples of E. bieneusi.

CONCLUSIONS

E. bieneusi and then Encephalitozoon spp. are common intestinal microsporidia in HIV + /AIDS patients and cancer patients undergoing chemotherapy in Mazandaran province. E. bieneusi genotype D seems to be the predominant genotype in Mazandaran province. Due to the considerable prevalence of intestinal microsporidia, physicians are advised to pay more attention to this opportunistic infection in high-risk groups.

Intestinal microsporidiosis among HIV/AIDS patients receiving antiretroviral therapy in Sana'a city, Yemen: first report on prevalence and predictors

Background

Intestinal microsporidiosis is an opportunistic infection associated with persistent diarrhea among HIV/AIDS patients. In Yemen, however, its epidemiology is unknown. Therefore, this study determined its prevalence and predictors among HIV/AIDS patients receiving antiretroviral therapy (ART) in Sana’a city, the capital of Yemen.

Methods

This cross-sectional study included 402 patients receiving ART at Al-Jomhori Educational Hospital in Sana’a from November 2019 to December 2020. Data about demographics, clinical characteristics and risk factors were collected using a pre-designed questionnaire. Stool samples were collected and examined for microsporidian spores using the Gram-chromotrope Kinyoun staining. Blood samples were also collected and used for CD4 cell counting by flow cytometry. Univariate analysis was used to test the association of patients’ characteristics and risk factors with intestinal microsporidiosis. Multivariable logistic regression was then used to identify the independent predictors of infection. Statistical significance was considered at P-values < 0.05.

Results

Intestinal microsporidiosis was prevalent among 14.2% (57/402) of HIV/AIDS patients and was significantly associated with diarrhea (OR 3.4, 95% CI 1.7–6.6; P = 0.001). The significant independent predictors of infection were < 200 CD4 cells/µl (AOR 3.2, 95% CI 1.5–6.9; P = 0.003), not washing hands after contacting soil (AOR 2.5, 95% CI 1.1–5.4; P = 0.026) and before eating (AOR 3.1, 95% CI 1.5–6.4; P = 0.003), eating unwashed raw produce (AOR 2.5, 95% CI 1.2–5.3; P = 0.017) and absence of indoor latrines (AOR 6.2, 95% CI 1.5–25.9; P = 0.012).

Conclusions

The prevalence of intestinal microsporidiosis among HIV/AIDS patients in Sana'a is high and comparable to that reported from several other countries, being prevalent among approximately 14.0% of patients and significantly associated with diarrhea. It could be predicted among patients who have < 200 CD4 cells/µl, have poor hand hygiene after contacting soil and before eating, usually eat unwashed raw produce, or do not possess indoor latrines. Large-scale studies on its epidemiology and predictors among HIV/AIDS patients across the country are warranted.

Identification of two potential aetiological agents of chronic diarrhoea in an immunocompromised patient in Cuba using conventional and molecular diagnostic techniques

The aetiology of diarrhoea in a patient in Cuba with HIV was investigated. Although molecular diagnostics are still not used in many under-resourced settings, here traditional methods were supported by use of PCR. This approach enabled detection of a dual infection (Cystoisospora belli and Enterocytozoon bieneusi), the latter of which was not identified by microscopy with Didier's trichromic staining.

Microsporidiosis in Humans

Microsporidia are obligate intracellular pathogens identified ∼150 years ago as the cause of pébrine, an economically important infection in silkworms. There are about 220 genera and 1,700 species of microsporidia, which are classified based on their ultrastructural features, developmental cycle, host-parasite relationship, and molecular analysis. Phylogenetic analysis suggests that microsporidia are related to the fungi, being grouped with the Cryptomycota as a basal branch or sister group to the fungi. Microsporidia can be transmitted by food and water and are likely zoonotic, as they parasitize a wide range of invertebrate and vertebrate hosts. Infection in humans occurs in both immunocompetent and immunodeficient hosts, e.g., in patients with organ transplantation, patients with advanced human immunodeficiency virus (HIV) infection, and patients receiving immune modulatory therapy such as anti-tumor necrosis factor alpha antibody. Clusters of infections due to latent infection in transplanted organs have also been demonstrated. Gastrointestinal infection is the most common manifestation; however, microsporidia can infect virtually any organ system, and infection has resulted in keratitis, myositis, cholecystitis, sinusitis, and encephalitis. Both albendazole and fumagillin have efficacy for the treatment of various species of microsporidia; however, albendazole has limited efficacy for the treatment of Enterocytozoon bieneusi. In addition, immune restoration can lead to resolution of infection. While the prevalence rate of microsporidiosis in patients with AIDS has fallen in the United States, due to the widespread use of combination antiretroviral therapy (cART), infection continues to occur throughout the world and is still seen in the United States in the setting of cART if a low CD4 count persists.

Prevalence and Genetic Characterization of Cryptosporidium and Microsporidia Infecting Hematological Malignancy Patients

PURPOSE

To evaluate the prevalence of Cryptosporidium and Microsporidia, associated risk factors and species identification in patients with haematological malignancies (HM).

METHODS

A total of 148 consecutive patients with HM and 101 healthy subjects were evaluated for Cryptosporidium and Microsporidia using modified Kinyoun and modified Trichrome staining. Clinical, demographic and laboratory parameters were studied. The species of Cryptosporidium and Microsporidia were studied using PCR-RFLP.

RESULTS

Of 148 HM patients initially screened, 47 were excluded from the final analysis due to inadequate clinical records. Patients with HM [n = 101, 63 (62.4%) male] more often had Cryptosporidium than healthy subjects [n = 101, 65 (74.4%) male] [3/101 (3%) vs. 0/101 (0%), p = 0.02]. Two of 101 (2%) HM patients and none of the healthy subjects had Microsporidia (p = 0.155). Diarrhea was more prevalent in HM patients with Cryptosporidium than those without [3, 100% vs. 39/96, 40.62%; p = 0.04). Both patients infected with Microsporidia presented with persistent diarrhea and fever. Cryptosporidium hominis was identified in all the three HM patients. Enterocytozoon bieneusi was identified in one HM patient infected with Microsporidia, which was classified as genotype Ind2.

CONCLUSION

Cryptosporidium and Microsporidia may infect HM patients leading to overwhelming diarrhea. The commonest species of Cryptosporidium and Microsporidia found to infect HM patients are C. hominis and E. bieneusi.

Advancement in our understanding of immune response against Encephalitozoon infection

Microsporidia are a group of obligate, intracellular, spore-forming eukaryotic pathogens, which predominantly infects immunocompromised individuals worldwide. Encephalitozoon spp. is one of the most prevalent microsporidia known to infect humans. Host immune system plays a major role in combating pathogens including Encephalitozoon spp. infecting humans. Both innate and adaptive arms of host immune system work together in combating Encephalitozoon infection. Researchers are conducting studies to elucidate the role of both arms of immune system against Encephalitozoon infection. In addition to cell-mediated adaptive immunity, role of innate immunity is also being highlighted in clearance of Encephalitozoon spp. from host body. Therefore, the current review will give a clear and consolidated update on the role of innate as well as adaptive immunity in protection against Encephalitozoon spp.

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.

Prevalence, genetic diversity and implications for public health of Enterocytozoon bieneusi in various rodents from Hainan Province, China

Background

Rodents, globally overpopulated, are an important source for zoonotic disease transmission to humans, including Enterocytozoon bieneusi (one of the most prevalent zoonotic pathogens). Here, we studied the prevalence and performed genetic analyses of E. bieneusi in rodents from the Hainan Province of China.

Methods

A total of 603 fresh fecal samples were gathered from 369 wild rats, 117 bamboo rats, 93 Asiatic brush-tailed porcupine and 24 red-bellied squirrels. The wild rats were identified to the species level by amplification of a 421-bp region of the cytb gene from fecal DNA using PCR. Genotype analysis was performed by amplification of the internal transcribed spacer (ITS) region of rDNA of E. bieneusi using PCR.

Results

Seven wild rat species were identified. The average rate of infection with E. bieneusi was 15.8% (95/603) with 18.7% (69/369) in wild rats, 11.9% (25/210) in farmed rodents and 4.2% (1/24) in red-bellied squirrels. Sixteen E. bieneusi genotypes were identified, including 9 known genotypes (D, Type IV, PigEBITS7, Peru8, Peru11, ESH02, S7, EbpA and CHG5), and 7 novel genotypes (HNR-I to HNR-VII). Genotype D (44.2%, 42/95) predominated, followed by PigEBITS7 (20.0%, 19/95), HNR-VII (15.8%, 15/95), Type IV (5.3%, 5/95), HNR-III (2.1%, 2/95), HNR-VI (2.1%, 2/95) and each of the remaining 10 genotypes (1.1%, 1/95). The phylogenetic analysis of the ITS region of E. bieneusi divided the identified genotypes into the following four groups: Group 1 (n = 13), Group 2 (n = 1), Group 12 (n = 1), and the novel Group 13 (n = 1).

Conclusions

To our knowledge, this is the first report on the identification of E. bieneusi in rodents from Hainan, China. The zoonotic potential of the identified E. bieneusi genotypes suggested that the rodents poses a serious threat to the local inhabitants. Thus, measures need to be taken to control the population of wild rats in the areas investigated in this study, along with identification of safe methods for disposal of farmed rodent feces. Additionally, the local people should be made aware of the risk of disease transmission from rodents to humans.

Evidence for Zoonotic Potential of Enterocytozoon bieneusi in Its First Molecular Characterization in Captive Mammals at Bangladesh National Zoo

To determine the occurrence and genotypes of Enterocytozoon bieneusi in captive mammals at Bangladesh National Zoo and to assess their zoonotic significance, 200 fecal samples from 32 mammalian species were examined using a nested PCR and sequencing of internal transcribed spacer (ITS) gene. Enterocytozoon bieneusi was detected in 16.5% (33/200) of the samples. Seven different ITS genotypes were identified, including two known genotypes (D and J) and five new ones (BAN4 to BAN8). Genotype D was the most common genotype being observed in 19 isolates. In phylogenetic analysis, four genotypes (D, BAN4, BAN5, and BAN6), detected in 30 isolates (90.9%), belonged to Group 1 having zoonotic potential. The sequence of genotype J found in a Malayan pangolin was clustered in so-called ruminant-specific Group 2. The other two genotypes BAN7 and BAN8 were clustered in primate-specific Group 5. To our knowledge, this is the first report of molecular characterization of E. bieneusi in Bangladesh, particularly in captive-bred wildlife in this country. The potentially zoonotic genotypes of E. bieneusi are maintained in zoo mammals that may transmit among these animals and to the humans through environmental contamination or contact.

A new scope for orlistat: Effect of approved anti-obesity drug against experimental microsporidiosis

As the current therapies for intestinal microsporidiosis are either inconsistent in their efficacies or hampered by several adverse effects, alternative antimicrosporidial agents are being sought. The present study is the first that was designed to evaluate the potency of orlistat, an approved anti-obesity drug, against intestinal microsporidiosis caused by both Enterocytozoon bieneusi and Encephalitozoon intestinalis. Results were assessed through studying fecal and intestinal spore load, intestinal histopathological changes, viability, and infectivity of spores from treated animals. Results showed that orlistat has promising antimicrosporidia potential, with better results in E. intestinalis than E. bieneusi. The animals that received orlistat showed statistically significant decrease in the fecal and intestinal spore load, when compared to the corresponding control infected nontreated mice. The results were insignificant compared to fumagillin and albendazole. Light microscopic examination of stained intestinal sections revealed amelioration of the pathological changes and decreased inflammatory cells detected in the control infected nontreated mice. Spores encountered from stool of orlistat-treated E. bieneusi and E. intestinalis mice showed low viability and significant reduction of infectivity versus their control. Thus, considering the results of the present work, orlistat proved its effectiveness against the intestinal microsporidial infection.

Genotypes and public health potential of Enterocytozoon bieneusi and Giardia duodenalis in crab-eating macaques

BACKGROUND

Enterocytozoon bieneusi and Giardia duodenalis are common human and animal pathogens. Studies have increasingly shown that non-human primates (NHPs) are common hosts of these two zoonotic parasites. However, few studies have explored the genetic diversity and public health potential of these pathogens in laboratory monkeys. In this study, we examined the genetic diversity of the two pathogens in crab-eating macaques (Macaca fascicularis) in a commercial facility in Hainan, China.

RESULTS

Enterocytozoon bieneusi and G. duodenalis were detected by PCR analysis in 461/1452 (31.7%) and 469/1452 (32.3%) fecal specimens from the animals, respectively. Significantly higher detection rates of E. bieneusi were detected in males (36.5%, 258/706) than in females (26.7%, 160/599; χ2 = 14.391, P = 0.0001), in animals with loose stools (41.4%, 151/365) than those with normal stool (28.5%, 310/1087; χ2 = 20.83, P < 0.0001), and in animals of over 3 years of age (38.6%, 135/350) than those of 1-3 years (29.6%, 326/1,102; χ2 = 9.90, P = 0.0016). For G. duodenalis, the detection rate in males (33.4%, 236/706) was higher than in females but not statistically significant (30.2%, 181/599; χ2 = 1.54, P = 0.2152), in monkeys with loose stools (41.1%, 150/365) than those with normal stools (29.3%, 319/1087; χ2 = 17.25, P < 0.0001), and in monkeys of 1-3 years of age (36.6%, 403/1102) than those over 3 years (18.9%, 66/350; χ2 = 38.11, P < 0.0001). Nine E. bieneusi genotypes were detected in this study by DNA sequence analysis of the internal transcribed spacer of the rRNA gene, namely Type IV (236/461), Peru8 (42/461), Pongo2 (27/461), Peru11 (12/461), D (4/461) and PigEbITS7 (1/461) previously seen in NHPs as well as humans, and CM1 (119/461), CM2 (17/461) and CM3 (3/461) that had been only detected in NHPs. DNA sequence analyses of the tpi, gdh and bg loci identified all G. duodenalis specimens as having assemblage B. Altogether, eight (4 known and 4 new), seven (6 known and 1 new) and seven (4 known and 3 new) subtypes were seen at the tpi, gdh and bg loci, leading to the detection of 53 multi-locus genotypes (MLG-B-hn01 to MLG-B-hn53). Most of them were genetically related to those previously seen in common Old-World monkeys.

CONCLUSIONS

Data from this study indicate a common occurrence of zoonotic genotypes of E. bieneusi and assemblage B of G. duodenalis in farmed crab-eating macaques in Hainan, China.

First survey of Enterocytozoon bieneusi and dominant genotype Peru6 among ethnic minority groups in southwestern China's Yunnan Province and assessment of risk factors

BACKGROUND

Enterocytozoon bieneusi is the most common microsporidian species causing diarrhea and other intestinal disorders in humans and animals. Like other infectious diseases, microsporidiosis usually disproportionately affects poor populations. In China, some ethnic minority areas remain poor. Currently, no information of E. bieneusi infection is available in minority populations. The present aims were to understand occurrence and genetic characterizations of E. bieneusi in ethnic minority groups from a poverty-stricken ethnic township in Yunnan Province, and to assess risk factors for E. bieneusi infection.

METHODOLOGY/PRINCIPAL FINDINGS

289 fecal specimens were collected from Yao people (one specimen each) with and without diarrhea, in Yunnan Province. E. bieneusi was identified and genotyped by PCR and sequence analysis of the ITS region of the rRNA gene. An average prevalence of 8.30% (24/289) was observed and four genotypes were identified-genotype Peru6 (n = 21) and three novel genotypes (one each). Genotype Peru6 was detected in two family members in each of three families. In a phylogenetic analysis, all of four genotypes fell into group 1 with zoonotic potential. The people owning individual pit toilets had a statistically higher prevalence of E. bieneusi (16.67%, 12/72) than those using public pit toilets (6.06%, 12/198).

CONCLUSIONS/SIGNIFICANCE

This is the first report on occurrence and genetic characteristics of E. bieneusi in ethnic minority groups in China. Genotype Peru6 was found in humans in China for the first time and showed dominance in Yao people. The same genotype was found in some family members and all the genotypes fell into group 1, suggesting the possibility of anthroponotic and zoonotic transmissions. The majority (83.33%, 20/24) of E. bieneusi positive individuals did not present diarrhea. In any case, it is important to recognize their existence and the importance that asymptomatic individuals to E. bieneusi may have from an epidemiological point of view, as transmitters of this pathogen. The analysis of risk factors provides scientific evidence for the development of effective strategies for prevention and control of E. bieneusi infection.

Dominance of zoonotic genotype D of Enterocytozoon bieneusi in bamboo rats (Rhizomys sinensis)

Enterocytozoon bieneusi is an emerging zoonotic intestinal pathogen that infects humans and various animal species. Here, we aimed to determine the infection rate and genetic characteristics of E. bieneusi from bamboo rats from different regions of China using nested polymerase chain reaction-based amplification of the internal transcribed spacer region of the rRNA gene. A total of 435 bamboo rats fecal samples were collected from individual tank from Guangdong, Hunan, Jiangxi, Chongqing, and Guangxi, southeastern China. E. bieneusi was detected on 22 tanks (5.1%, 22/435), with a higher infection rate being observed among samples from Guangdong Province (10.9%, 5/46) compared with those from Hunan (9.3%, 10/107), Jiangxi (6.7%, 6/90), Chongqing (2.0%, 1/50), and Guangxi (0%, 0/142) (P < .01). Six genotypes were identified, including four known genotypes (D, EbpA, J, and PigEBITS7) and two novel genotypes (named BR1 and BR2). Of these, zoonotic genotype D was the most prevalent in the present study (n = 17). Phylogenetic analysis revealed that genotypes D, EbpA, and PigEBITS7 were clustered into Group 1, while genotypes J, BR1, and BR2 were clustered into Group 2. To our knowledge, this is the first report of E. bieneusi in bamboo rats. The identification of zoonotic genotype D as the predominant genotype in bamboo rats suggests that these animals represent a potential zoonotic risk for the transfer of the pathogen in China.

Molecular Phylodiagnosis of Enterocytozoon bieneusi and Encephalitozoon intestinalis in Children with Cancer: Microsporidia in Malignancies as an Emerging Opportunistic Infection

BACKGROUND : Microsporidia may cause infection in both immunocompromised and immunocompetent populations. The best strategy to control microsporidiosis is obtaining thorough knowledge of its outbreak and pathogenicity. PURPOSE : Because of the lack of precise estimation of microsporidia prevalence among Iranian children with cancer, the current study aimed at evaluating the rate of intestinal microsporidia in children undergoing chemotherapy.

METHODS

 Patients with cancer undergoing chemotherapy in a children's hospital in Northwestern Iran were studied; 132 stool samples were collected and stained by the Weber and Ryan-blue modified trichrome staining techniques. The extracted DNA samples were evaluated by the nested polymerase chain reaction (PCR) method. All positive isolates were sequenced for genotyping and phylogenetic analysis.

RESULTS

A total of 17 (12.8%) samples were microscopically positive for microsporidia infection, whereas only 14 (10.6%) cases were positive based on nested PCR results. In the positive samples detected with nested PCR, the frequency of Enterocytozoon bieneusi and Encephalitozoon intestinalis infections was 71.4% (n = 10) and 28.6% (n = 4), respectively. After sequencing and phylogenetic analysis, the genotype of E. bieneusi was type D and the sequences of the isolated species were similar to those of the registered ones.

CONCLUSION

E. bieneusi is a major contributor to microsporidiosis in young immunocompromised patients in Iran. Microsporidia species are well-detected when confirmatory techniques such as molecular methods are in agreement with staining. So, to ensure this, a suggestion has been made to introduce a certain diagnostic test for microsporidiosis.

Molecular Diagnosis of Microsporidia among Immunocompromised Patients in Kuala Lumpur, Malaysia

Microsporidia are obligate intracellular parasitic fungi causing chronic diarrhea, particularly among immunocompromised patients. The current method used for diagnosis is based on conventional microscopy, which does not differentiate parasites at the species level. The present study was carried out to identify microsporidian species in immunocompromised patients. From March 2016 to March 2017, a total of 289 archived stool samples were examined microscopically for microsporidian spores using Gram-chromotrope Kinyoun (GCK) stain. Positive stool samples by microscopy were subjected to polymerase chain reaction and sequencing for species identification. Based on microscopy examination, the overall prevalence of microsporidian infections was 32.2% (93/289; 95% CI = 27.1-37.8). Of these stool samples, 45 samples were successfully amplified and confirmed as Enterocytozoon bieneusi. No Encephalitozoon intestinalis was detected. Accurate identification of species might help clinicians to decide appropriate management strategies as dissemination risks and treatment response vary for different species, hence improving the management of microsporidian infections.

The Potential Role of Synanthropic Rodents and Flies in the Transmission of Enterocytozoon bieneusi on a Dairy Cattle farm in China

Enterocytozoon bieneusi causes microsporidiosis, a condition with complex epidemiology involving both direct and indirect transmission routes. To assess the potential role of synanthropic rodents and flies in the transmission of this pathogen, a total of 277 cattle fecal samples, 199 synanthropic rodents, and 50 batches of 20 flies were collected from a cattle farm. These samples were screened for the presence of E. bieneusi by PCR and sequencing of the internal transcribed spacer (ITS) region of the rRNA gene. The positive rates of cattle, synanthropic rodents, and flies were 11.9% (33/277), 4.0% (8/199) and 12.0% (6/50), respectively. Nineteen genotypes were identified, including 11 known genotypes (BEB6, I, COS-I, EbpC, D, J, CHS5, CHG1 to CHG3 and CHG14) and eight novel genotypes (named CHC9 to CHC16). The dominant genotype detected in the present study, BEB6, was found in all three categories of hosts. Moreover, human pathogenic genotypes D and EbpC were also observed in both synanthropic rodents and flies. These results demonstrate that synanthropic rodents and flies may act as biological disseminator or mechanical vector in the transmission of microsporidiosis to humans. Efforts should be made to minimize threats from these commensal animals to public health.

Prevalence of Cryptosporidium, microsporidia and Isospora infection in HIV-infected people: a global systematic review and meta-analysis

BACKGROUND

Diarrhea caused by opportunistic intestinal protozoa is a common problem in HIV infection. We aimed to establish the prevalence of Cryptosporidium, misrosporidia, and Isospora in HIV-infected people using a systematic review and meta-analysis, which is central to developing public policy and clinical services.

METHODS

We searched PubMed, ScienceDirect, Google Scholar, Embase, Chinese Web of Knowledge, Wanfang, and Chongqing VIP databases for studies reporting Cryptosporidium, microsporidia, or Isospora infection in HIV-infected people. We extracted the numbers of people with HIV and protozoa infection, and estimated the pooled prevalence of parasite infection by a random effects model.

RESULTS

Our research identified 131 studies that reported Cryptosporidium, microsporidia, and Isospora infection in HIV-infected people. We estimated the pooled prevalence to be 14.0% (3283/43,218; 95% CI: 13.0-15.0%) for Cryptosporidium, 11.8% (1090/18,006; 95% CI: 10.1-13.4%) for microsporidia, and 2.5% (788/105,922; 95% CI: 2.1-2.9%) for Isospora. A low prevalence of microsporidia and Isospora infection was found in high-income countries, and a high prevalence of Cryptosporidium and Isospora infection was found in sub-Saharan Africa. We also detected a high prevalence of Cryptosporidium, microsporidia, and Isospora infection in patients with diarrhea. Sensitivity analysis showed that three studies significantly affect the prevalence of Isospora, which was adjusted to 5.0% (469/8570; 95% CI: 4.1-5.9%) by excluding these studies.

CONCLUSIONS

Our findings suggest that HIV-infected people have a high prevalence of Cryptosporidium, microsporidia, and Isospora infection in low-income countries and patients with diarrhea, especially in sub-Saharan Africa, reinforcing the importance of routine surveillance for opportunistic intestinal protozoa in HIV-infected people.

Infection by and genotype characteristics of Enterocytozoon bieneusi in HIV/AIDS patients from Guangxi Zhuang autonomous region, China

Background

Enterocytozoon bieneusi has been increasingly reported to infect humans and various mammals. Microsporidia cause diarrhea in HIV-infected patients worldwide. PCR amplification and sequencing based on the internal transcribed spacer region have been used to describe the genotypes of E. bieneusi and transmission of microsporidiosis.

Methods

In this study, we examined E. bieneusi infection and genotypes in HIV-positive patients in Guangxi, China. Stool specimens were collected from 285 HIV-positive patients and 303 HIV-negative individuals. E. bieneusi genotypes were characterized using nested PCR and sequencing.

Results

Thirty-three (11.58%) HIV-positive patients were infected with microsporidia, and no infection was found in the 303 healthy controls. Three new genotypes were identified and named as GX25, GX456, and GX458; four known genotypes, PigEBITS7, Type IV/K, D, and Ebpc, were also identified. Our data showed that the positive rate for microsporidia was significantly higher in the rural patients than in the other occupation groups. In addition, the positive rate for microsporidia was significantly higher in the patients who drink unboiled water than in those with other drinking water sources.

Conclusions

Our results will provide baseline data for preventing and controlling E. bieneusi infection in HIV/AIDS patients. Further studies are required to clarify the epidemiology and potential sources of microsporidia. Our study showed that microsporidium infection occurs in the HIV/AIDS patients in Guangxi, China.

Electronic supplementary material

The online version of this article (10.1186/s12879-017-2787-9) contains supplementary material, which is available to authorized users.

Genotyping of Enterocytozoon bieneusi and Subtyping of Blastocystis in Cancer Patients: Relationship to Diarrhea and Assessment of Zoonotic Transmission

Enterocytozoon bieneusi (E. bieneusi) and Blastocystis are common pathogens responsible for diarrhea in humans, especially in immunocompromised individuals. The number of cancer patients has been increasing and diarrhea is a common clinical symptom in the treatment of cancers. To understand the prevalences and genotypes/subtypes of E. bieneusi and Blastocystis in cancer patients in China, to track the infection sources, and to explore the relationships between E. bieneusi and Blastocystis infections and diarrhea, 381 fecal specimens were collected from cancer patients. Each of them was analyzed for the presence of E. bieneusi and Blastocystis by PCR amplifying and sequencing the ITS region of the rRNA gene and the barcode region of the SSU rRNA gene, respectively. 1.3 and 7.1% of cancer patients were positive for E. bieneusi and Blastocystis, respectively. No statistical differences were observed in the infection rates between the groups by age, gender, and residence. E. bieneusi and Blastocystis were both significantly more common in cancer patients with diarrhea, and significant relationship of Blastocystis to diarrhea was found in chemotherapy group. Two E. bieneusi genotypes (D and a novel one named as HLJ-CP1) and two Blastocystis subtypes (ST1 and ST3) were identified with three novel ST1 sequences. This is the first report of occurrence and molecular characterizations of E. bieneusi and Blastocystis in cancer patients in China. E. bieneusi genotype D and Blastocystis ST1 and ST3 have been identified in humans and animals while one novel E. bieneusi genotype falling into zoonotic group 1, implying a potential of zoonotic transmission.

Subtyping of Cryptosporidium cuniculus and genotyping of Enterocytozoon bieneusi in rabbits in two farms in Heilongjiang Province, China

Cryptosporidium spp. and Enterocytozoon bieneusi are two prevalent opportunistic pathogens in humans and animals. Currently, few data are available on genetic characterization of both pathogens in rabbits in China. The aim of the present study was to understand prevalence and genetic characterization of Cryptosporidium spp. and E. bieneusi in rabbits. We collected 215 fecal samples from 150 Rex rabbits and 65 New Zealand White rabbits on two different farms in Heilongjiang Province, China. Cryptosporidium spp. and E. bieneusi were tested by polymerase chain reaction (PCR) and sequencing the partial small subunit of ribosomal DNA (SSU rDNA) and the internal transcribed spacer (ITS) region of rDNA, respectively. Cryptosporidium was detected in 3.3% (5/150) of Rex rabbits and 29.2% (19/65) of New Zealand White rabbits. All the 24 Cryptosporidium isolates were identified as C. cuniculus. Enterocytozoon bieneusi was only found in 14.7% (22/150) of Rex rabbits. Five known genotypes: CHN-RD1 (n = 12), D (n = 3), Type IV (n = 2), Peru6 (n = 1), and I (n = 1), and three novel ones CHN-RR1 to CHN-RR3 (one each) were detected. By analyzing the 60-kDa glycoprotein (gp60) gene sequences of C. cuniculus isolates, three subtypes were obtained: VbA28 (n = 2), VbA29 (n = 16), and VbA32 (n = 3). All these three C. cuniculus subtypes were reported previously in humans. Four known E. bieneusi genotypes have been found to be present in humans. The three novel ones fell into zoonotic group 1. The results suggest zoonotic potential of C. cuniculus and E. bieneusi isolates in rabbits.