Molecular epidemiology of Enterocytozoon bieneusi and Encephalitozoon sp., among immunocompromised and immunocompetent subjects in Iran

Design and evaluation of loop-mediated isothermal amplification for rapid detection of Enterocytozoon bieneusi

Enterocytozoon bieneusi is one of the most prevalent microsporidia species, responsible for more than 90% of human and animal microsporidiosis. Microsporidia species, particularly E. bieneusi, are frequently reported from waterborne and foodborne outbreaks. Therefore, early detection is crucial in clinics and outbreak investigations. This study aimed to design a loop-mediated isothermal amplification (LAMP) for rapid detection of E. bieneusi. Total DNA was extracted from 30 E. bieneusi -positive samples, which had been confirmed with nested PCR. LAMP primers were designed based on the identical fragment of small subunit ribosomal RNA (SSU rRNA) gene. LAMP reactions were performed at 63 °C for 60 min. The sensitivity and specificity of the assay were analyzed and the results of amplification were compared to real-time PCR. Our results showed that the LAMP assay successfully amplified 25/30 (83.3%) samples. The specificity results indicated no false positive with other microorganisms. Furthermore, the LAMP method exhibited a sensitivity (limit of detection, LoD) as low as 34 ag/μL of total DNA. Compared to the LAMP assay, real-time PCR was able to detect all 30 nested PCR-positive samples. Our findings showed that the LAMP assay was able to detect 83.3% of E. bieneusi-positive samples. Although the current assay was not able to detect all nested PCR-positive samples, the lack of need for specific instruments, rapid processes, and high specificity makes LAMP assay a suitable tool for screening.

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.

Investigation of the presence of Enterocytozoon bieneusi and Encephalitozoon intestinalis in immunosuppressed patients with diarrhea by IFA and real time PCR methods

PURPOSE

This study aimed to investigate the frequency of Enterocytozoon bieneusi and Encephalitozoon intestinalis in patients with diarrhea in the immunosuppressed.

METHODS

Patients between the ages of 18-85 who applied to different clinics of Muş Bulanık and Bitlis State Hospitals and were referred to the microbiology or parasitology laboratory were selected for this study. A total of 200 individuals, including 88 immunosuppressed with diarrhea patients, 38 immunocompetent with diarrhea patients, 38 immunosuppressed without diarrhea patients, and 36 immunocompetent without diarrhea individuals, were included. Collected stool samples were evaluated using IFA-MAbs and real-time PCR methods to determine the frequency of E.intestinalis and E.bieneusi.

RESULTS

E. intestinalis was detected in 59 (29.5%) of 200 samples and E. bieneusi was detected in 46 (23.0%) of them. Mixed infection was detected in 16 (8%) of the positive samples. While there was no statistically significant difference between E. intestinalis positivity and gender, age, diarrhea status and immune system status, a statistically significant relationship was determined between E. bieneusi positivity and diarrhea. When the real-time PCR method was accepted as the gold standard, the sensitivity of the IFA-MAbs method in the diagnosis of E. intestinalis was 94.54%, the specificity was 97.24, the sensitivity in the diagnosis of E. bieneusi was 95.45%, and the specificity was 98.72%. The overall accuracy of the IFA-MAbs method was 96.5% for the diagnosis of E. intestinalis and 98% for the diagnosis of E. bieneusi.

CONCLUSIONS

The findings suggest that E. intestinalis and E. bieneusi should be considered in both immunosuppressed and healthy individuals with diarrhea. IFA-MAbs method can be used in addition to the real-time PCR method to diagnose E. intestinalis and E. bieneusi.

Molecular characterization of Cryptosporidium spp., Enterocytozoon bieneusi and Giardia duodenalis in laboratory rodents in China

Cryptosporidium spp., Enterocytozoon bieneusi and Giardia duodenalis are significant zoonotic intestinal pathogens that can cause gastrointestinal symptoms such as diarrhea and induce a host immune response. A total of 1237 fecal samples were collected from laboratory rodents (rats, mice and guinea pigs) from four different locations in China to investigate the infection rates and molecular characterization of these pathogens on experimental animals. Genomic DNA was extracted from each sample, and PCR amplifications were done. Overall, the Cryptosporidium spp. infection rate was 3.8% (47/1237). Four known Cryptosporidium species were identified, namely C. parvum, C. muris, C. tyzzeri and C. homai, the three former being zoonotic species. The overall E. bieneusi infection rate was 3.0% (37/1237). Seven known E. bieneusi genotypes, namely S7, BEB6, J, Henan-IV, CHG10, D and WL6, were detected by sequence analysis. Among these, genotypes D, Henan-IV and CHG10 have a high zoonotic risk. Giardia duodenalis was not detected at any of the three loci (SSU rRNA, bg and gdh) after PCR amplification. This study provides basic data for these pathogens in laboratory rodents in China and lays the foundation for their prevention and control in laboratory animals.

Zoonotic Enterocytozoon bieneusi genotypes in free-ranging and farmed wild ungulates in Spain

Microsporidia comprises a diverse group of obligate, intracellular, and spore-forming parasites that infect a wide range of animals. Among them, Enterocytozoon bieneusi is the most frequently reported species in humans and other mammals and birds. Data on the epidemiology of E. bieneusi in wildlife is limited. Hence, E. bieneusi was investigated in eight wild ungulate species present in Spain (genera Ammotragus, Capra, Capreolus, Cervus, Dama, Ovis, Rupicapra, and Sus) by molecular methods. Faecal samples were collected from free-ranging (n = 1058) and farmed (n = 324) wild ungulates from five Spanish bioregions. The parasite was detected only in red deer (10.4%, 68/653) and wild boar (0.8%, 3/359). Enterocytozoon bieneusi infections were more common in farmed (19.4%, 63/324) than in wild (1.5%, 5/329) red deer. Eleven genotypes were identified in red deer, eight known (BEB6, BEB17, EbCar2, HLJD-V, MWC_d1, S5, Type IV, and Wildboar3) and three novel (DeerSpEb1, DeerSpEb2, and DeerSpEb3) genotypes. Mixed genotype infections were detected in 15.9% of farmed red deer. Two genotypes were identified in wild boar, a known (Wildboar3) and a novel (WildboarSpEb1) genotypes. All genotypes identified belonged to E. bieneusi zoonotic Groups 1 and 2. This study provides the most comprehensive epidemiological study of E. bieneusi in Spanish ungulates to date, representing the first evidence of the parasite in wild red deer populations worldwide. Spanish wild boars and red deer are reservoir of zoonotic genotypes of E. bieneusi and might play an underestimated role in the transmission of this microsporidian species to humans and other animals.

Global molecular epidemiology of microsporidia in pigs and wild boars with emphasis on Enterocytozoon bieneusi: A systematic review and meta-analysis

BACKGROUND

Microsporidia are spore-forming intracellular pathogens with worldwide prevalence, causing emerging infections in humans and animals. Enterocytozoon bieneusi is a zoonotic species of microsporidia and is responsible for more than 90% of cases of microsporidiosis in humans and animals. Pigs and wild boars are important animal reservoirs of microsporidia. Hence, we aimed to estimate the global prevalence of microsporidia and genetic diversity of E. bieneusi in pigs and wild boars through a set of systematic review and meta-analysis (PRISMA) guidelines.

METHODS

Four databases (Web of Science, PubMed, Scopus and Google Scholar) were searched between January 1, 2000 and April 30, 2021. Regarding meta-analysis, the random-effect model was employed by forest plot with 95% confidence interval (CI).

RESULTS

After exclusion of irrelevant articles and duplication removal, 33 papers, including 34 datasets (30 datasets for domestic pigs and 4 for wild boars) finally meet the inclusion criteria to undergo meta-analysis. The pooled prevalence rates of microsporidia infection in domestic pigs and wild boars were 37.6% (95% CI: 30.8-44.9%) and 8.1% (95% CI: 2.1-26.8%), respectively. While, the pooled prevalence rates of E. bieneusi were 35% (95% CI: 28.4-42.2%) in domestic pigs and 10.1% (95% CI: 1.7-42.4%) in wild boars. The genotypes EbpA was the most reported genotype in domestic pigs and wild boars. Male animals had higher prevalence rates of microsporidia infection than females (27 vs. 17.4%, OR = 1.91; 95% CI, 0.77-4.71%).

CONCLUSION

This study indicates the important role of domestic pigs and wild boars as animal reservoir hosts of microsporidia. Thereby, strategies for control and prevention of these zoonotic pathogens should be designed in pigs and wild boars.

A Systematic Review and Meta-analysis on the Global Molecular Epidemiology of Microsporidia Infection Among Rodents: A Serious Threat to Public Health

BACKGROUND

Microsporidiosis as a zoonotic disease has caused serious health problems in high-risk groups, including immunosuppressed individuals. Among the potential animal reservoirs of microsporidia, rodents play a key role due to close-contact with humans and their dispersion in different environments. Therefore, this systematic review and meta-analysis aimed to assess the global status and genetic diversity of microsporidia infection in different rodents.

METHODS

The standard protocol of preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines were followed. Scopus, PubMed, Web of Science, and Google Scholar were searched from 1 January 2000 to 15 April 2021. All peer-reviewed original research articles describing the molecular prevalence of microsporidia infection in rodents were included. Inclusion and exclusion criteria were applied. The point estimates and 95% confidence intervals were calculated using a random-effects model. The variance between studies (heterogeneity) were quantified by I² index.

RESULTS

Of 1695 retrieved studies, 22 articles (including 34 datasets) were included for final meta-analysis. The pooled global molecular prevalence (95% CI) of microsporidia infection in rodents was 14.2% (95% CI 10.9-18.3%). The highest prevalence of microsporidia was found in Apodemus spp. 27.3% (95% CI 15-44.5%). Enterocytozoon bieneusi was the most common pathogen (26/34; 76.47% studies) according to PCR-based methods, and the genotype D as the highest reported genotype (15 studies).

CONCLUSIONS

The findings of the study showed a relatively high prevalence of microsporidia infection in rodents as a potential animal reservoir for infecting human. Given the relatively high incidence of microsporidiosis, designing strategies for control, and prevention of microsporidia infection in rodents should be recommended.

Chronic Infections in Mammals Due to Microsporidia

Microsporidia are pathogenic organism related to fungi. They cause infections in a wide variety of mammals as well as in avian, amphibian, and reptilian hosts. Many microsporidia species play an important role in the development of serious diseases that have significant implications in human and veterinary medicine. While microsporidia were originally considered to be opportunistic pathogens in humans, it is now understood that infections also occur in immune competent humans. Encephalitozoon cuniculi, Encephalitozoon intestinalis, and Enterocytozoon bieneusi are primarily mammalian pathogens. However, many other species of microsporidia that have some other primary host that is not a mammal have been reported to cause sporadic mammalian infections. Experimental models and observations in natural infections have demonstrated that microsporidia can cause a latent infection in mammalian hosts. This chapter reviews the published studies on mammalian microsporidiosis and the data on chronic infections due to these enigmatic pathogens.

Molecular epidemiology and genotype/subtype distribution of Blastocystis sp., Enterocytozoon bieneusi, and Encephalitozoon spp. in livestock: concern for emerging zoonotic infections

Intestinal parasitic infections have high prevalence rate in many regions especially in developing countries. The aim of this study was to determine the presence and genotype/subtype of some intestinal protozoa in livestock in Iran. Stool samples were collected from cattle, sheep, chickens, and horses. The presence of targeted parasites was evaluated using real-time PCR. Genotyping/subtyping of positive samples was characterized using sequencing of the ITS and barcoding region, respectively. Blastocystis sp., 27.7% (48/173) and Enterocytozoon bieneusi 26.0% (45/173) were the most frequent protozoa followed by Encephalitozoon spp., 0.57% (1/173). Cryptosporidium spp. were not detected among samples. Encephalitozoon spp., was detected only in chickens 2.2% (1/45). A statistically correlation was seen between animals and the prevalence of targeted protozoa. E. bieneusi genotypes I (9/38; 23.68%), BEB6 (22/38; 57.89%), D (6/38; 15.79%), and horse1 (1/38; 2.63%) were detected among samples. A statistically significant correlation was seen between the genotypes and animals (P ≤ 0.05). Blastocystis sp., ST1 (1/45; 2.22%), ST5 3/45; 6.66%), ST7 (1/45; 2.22%), ST10 (24/45; 53.33%), and ST14 (16/45; 35.55%) were characterized among samples. There was no significant correlation between certain subtypes and animals (P = 0.173). The presence of zoonotic potential genotypes of E. bieneusi in animals and zoonotic potential subtypes ST1 and ST7 among our samples provide a clue about the transmission dynamic of E. bieneusi and Blastocystis sp. between animals–animals and humans–animals.

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.

Encephalitozoon cuniculi takes advantage of efferocytosis to evade the immune response

Microsporidia are recognized as opportunistic pathogens in individuals with immunodeficiencies, especially related to T cells. Although the activity of CD8+ T lymphocytes is essential to eliminate these pathogens, earlier studies have shown significant participation of macrophages at the beginning of the infection. Macrophages and other innate immunity cells play a critical role in activating the acquired immunity. After programmed cell death, the cell fragments or apoptotic bodies are cleared by phagocytic cells, a phenomenon known as efferocytosis. This process has been recognized as a way of evading immunity by intracellular pathogens. The present study evaluated the impact of efferocytosis of apoptotic cells either infected or not on macrophages and subsequently challenged with Encephalitozoon cuniculi microsporidia. Macrophages were obtained from the bone marrow monocytes from C57BL mice, pre-incubated with apoptotic Jurkat cells (ACs), and were further challenged with E. cuniculi spores. The same procedures were performed using the previously infected Jurkat cells (IACs) and challenged with E. cuniculi spores before macrophage pre-incubation. The average number of spores internalized by macrophages in phagocytosis was counted. Macrophage expression of CD40, CD206, CD80, CD86, and MHCII, as well as the cytokines released in the culture supernatants, was measured by flow cytometry. The ultrastructural study was performed to analyze the multiplication types of pathogens. Macrophages pre-incubated with ACs and challenged with E. cuniculi showed a higher percentage of phagocytosis and an average number of internalized spores. Moreover, the presence of stages of multiplication of the pathogen inside the macrophages, particularly after efferocytosis of infected apoptotic bodies, was observed. In addition, pre-incubation with ACs or IACs and/or challenge with the pathogen decreased the viability of macrophages, reflected as high percentages of apoptosis. The marked expression of CD206 and the release of large amounts of IL-10 and IL-6 indicated the polarization of macrophages to an M2 profile, compatible with efferocytosis and favorable for pathogen development. We concluded that the pathogen favored efferocytosis and polarized the macrophages to an M2 profile, allowing the survival and multiplication of E. cuniculi inside the macrophages and explaining the possibility of macrophages acting as Trojan horses in microsporidiosis.

Global prevalence of microsporidia infection in cats: A systematic review and meta-analysis of an emerging zoonotic pathogen

Microsporidiosis in pet and stray cats is an emerging zoonotic threat with public health significance worldwide. However, the epidemiological patterns of feline microsporidiosis is still neglected around the world. Hence, current systematic review and meta-analysis aimed at characterizing the prevalence estimates and genotypes of microsporidian parasites among cats of the world. Several databases (PubMed, Web of Science, Scopus, and Google scholar) were systematically explored to find relevant studies. Evaluation of the weighted prevalences among included studies was done using random-effects model. Totally, 30 studies (34 datasets) reported from 19 countries were included in the present work. Microsporidia infection demonstrated higher prevalence rates using microscopy 29.7 % (19.7-42.2 %), followed by serology and molecular techniques with 11 % (4.6-24.2 %) and 8.2 % (5.9-11.4 %), respectively. Moreover, molecular data showed Enterocytozoon bieneusi as the most dominant reported species with 7.4 % (5.1-10.5 %). Also, investigations (11 studies) mostly isolated D genotype among all E. bieneusi genotypes. These results highlight cats as a potential reservoir for acquisition of microsporidia infection in humans, and surveillance programs should be implemented in high-risk areas.

Molecular detection and genotype identification of E. cuniculi from pet rabbits

Encephalitozoon cuniculi is a microsporidian which is frequently reported from rabbits. This microorganism can either ravage rabbit farms or transmit to humans from pet rabbits. This study aimed to investigate the prevalence and the genotype distribution of E. cuniculi among pet rabbits. In this study urine samples were collected from 50 pet rabbits, aged 2 months to 3 years, admitted to teaching veterinary hospital. Four races Lop, Dutch, Mix, and Angora were screened for E. cuniculi. The clinical symptoms were recorded and total DNA was extracted from urine samples. E. cuniculi was identified using amplification of the small subunit ribosomal RNA (ssu rRNA) gene and its genotypes were characterized using PCR/sequencing of the polar tube protein (PTP) gene. Phylogenetic tree was drawn to confirm the characterized genotypes. Out of 50 samples, 41 (82 %) of rabbits were asymptomatic, while nine (18 %) had at least one of symptoms including head-tilt, circling, and ataxia. A statistical correlation was seen between mean age + SD and symptoms (P-value = 0.039). The presence of E. cuniculi was confirmed in 16/50 (32 %) rabbits and all of them were identified as the genotype I. Our findings represented no consistency between E. cuniculi PCR - positive and the presence of symptoms (P-value = 0.318). Our results showed positive correlation between symptoms and age; however, the lack of correlation between PCR results with age may signify the latent infection in younger rabbits. All identified E. cuniculi were the genotype I, which is reported from rabbits and humans, highlighting the zoonotic concern for this genotype, particularly among subjects who keep pet rabbits.

A systematic review and meta-analysis on the global prevalence of microsporidia infection among dogs: a zoonotic concern

Background

Microsporidiosis is an emerging zoonotic disease that is considered a global public health concern. Dogs are suggested as one of potential reservoirs for transmitting the microsporidia infection to humans. However, there is little data on distribution of microsporidia in dogs. The current study aimed to evaluate the global prevalence and genetic diversity of microsporidia infection among the dog population.

Methods

We searched four major databases for studies reporting the prevalence of microsporidia in dogs until 30 May 2020. A random-effects model was used to estimate the overall and the subgroup-pooled prevalence of microsporidia across studies.

Result

Finally, a total of 32 studies (including 37 datasets) from 17 countries were included in this meta-analysis. The overall prevalence (95% CI) of microsporidia infection was estimated at 23.1% (13.5–36.8%) using microscopic methods, 20.9% (14.6–29%) using serological methods, and 8.4% (6.1–11.5%) using molecular methods. Molecular methods showed that the highest number of reports was related to Enterocytozoon bieneusi with a pooled prevalence of 6.5% (4.9–8.7%). Considering E. bieneusi genotypes, most studies reported the PtEb IX (10 studies) and the D (eight studies) genotypes.

Conclusion

These results emphasize the role of a dog as a reservoir host for human-infecting microsporidia. In addition, monitoring programs for human-infecting microsporidia in animals with close contact to humans should be considered.

Alternatives in Molecular Diagnostics of Encephalitozoon and Enterocytozoon Infections

Microsporidia are obligate intracellular pathogens that are currently considered to be most directly aligned with fungi. These fungal-related microbes cause infections in every major group of animals, both vertebrate and invertebrate, and more recently, because of AIDS, they have been identified as significant opportunistic parasites in man. The Microsporidia are ubiquitous parasites in the animal kingdom but, until recently, they have maintained relative anonymity because of the specialized nature of pathology researchers. Diagnosis of microsporidia infection from stool examination is possible and has replaced biopsy as the initial diagnostic procedure in many laboratories. These staining techniques can be difficult, however, due to the small size of the spores. The specific identification of microsporidian species has classically depended on ultrastructural examination. With the cloning of the rRNA genes from the human pathogenic microsporidia it has been possible to apply polymerase chain reaction (PCR) techniques for the diagnosis of microsporidial infection at the species and genotype level. The absence of genetic techniques for manipulating microsporidia and their complicated diagnosis hampered research. This study should provide basic insights into the development of diagnostics and the pitfalls of molecular identification of these ubiquitous intracellular pathogens that can be integrated into studies aimed at treating or controlling microsporidiosis.

Intestinal microsporidia infection among cat owners and non-pet owners in Iran: a case-control study

Microsporidia is a group of spore-forming microorganisms with zoonotic potential. This study aimed to compare intestinal microsporidia infections in cat owners and non-pet owners. In total, 210 fecal samples were collected from indoor cats, cat owners, and non-pet owners. DNA extraction was performed and the small subunit ribosomal RNA (SSU rRNA) gene was amplified. To characterize the genotypes, the internal transcribed spacer (ITS) fragment was amplified and sequenced. The phylogenetic trees were drawn to evaluate the relationship among Enterocytozoon bieneusi isolates. Two (2.9%) and one (1.4%) fecal samples from cat owners and one (1.4%) and two (2.9%) fecal samples from non-pet owners were positive for E. bieneusi and Encephalitozoon intestinalis, respectively. E. bieneusi was detected in two cat samples (2.9%). Same infection was not seen between infected cats and their owners. There was no significant difference between the prevalence rate of microsporidia among the cat owners and non-pet owners. Indeed, the genotypes L and type IV were seen in cats, while the genotype D was only detected in human. In this study, E. bieneusi and E. intestinalis were more prevalent among the cat owners and non-pet owners, respectively. Indeed, the higher prevalence of E. bieneusi in cats and their owners might be resulted from the worldwide distribution of this species.