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

Molecular evidence of host range expansion of Enterocytozoon bieneusi in captive wildlife at Beijing Zoo, China

Enterocytozoon bieneusi has become a significant public health concern due to its ability to infect both humans and animals on a global scale. However, there is a paucity of epidemiological data regarding this pathogen in captive wildlife. In this study, 445 fecal samples were collected from captive animals at Beijing Zoo and analyzed using PCR targeting the internal transcribed spacer (ITS) of the nuclear ribosomal DNA of E. bieneusi. The overall prevalence was determined to be 7.0 % (31/445), with infection rates of 7.1 % (23/322) in mammals and 6.5 % (8/123) in Aves. Genotypic characterization 12 distinct genotypes, including 11 known genotypes belonging to Groups 1 (EbpA, PigEBITS7, D, HND-1, SC02, CM16, MJ13), 2 (BEB6), 7 (CM 4), and 13 (CHB1, CHK1), along with one novel genotype (BJZ-1) in Group 1. The detection of zoonotic genotypes from Groups 1 and 2 underscores the potential for cross-species transmission between captive wildlife and humans. Notably, this study presents the first molecular identification of E. bieneusi in caracals, polar bears, giant anteaters, and grey herons, thereby significantly expanding the known host range of this pathogen. These findings emphasise the necessity of implementing One Health surveillance strategies to monitor and mitigate zoonotic risks at the human-animal interface.

Molecular prevalence and genetic characterization of Enterocytozoon bieneusi in cattle in a dairy farm in Türkiye

BACKGROUND

Microsporidia, which are unicellular and obligate intracellular eukaryotic pathogens, can infect many animal species and humans. Cattle are known to be an important source for the spread of Enterocytozoon bieneusi (E. bieneusi) to humans and animals. Therefore, this study aimed to investigate E. bieneusi in fecal samples collected from cattle and environmental samples within a dairy farm and to genotype E. bieneusi-positive samples. For this purpose, a Nested PCR targeting a region of the E. bieneusi ribosomal DNA internal transcribed spacer (ITS) was applied to the DNA samples extracted from fecal (n = 47) or environmental samples (n = 41). Later, sequencing data belonging to E. bieneusi-positive samples were analyzed by BLAST and phylogenetic analysis for genotyping.

RESULTS

Nested PCR screening detected 15 E. bieneusi-positive samples and among them six (12.8%; 6/47) were detected in fecal samples while nine (21.9%; 9/41) were detected in environmental samples (including drinking water containers, mangers, feeding bottle, milk heating tank and towel). When cattle were categorized by their age, the molecular prevalence of E. bieneusi for cattle < 2 months old was detected as 19.2% (5/26). However, in cattle group > 2 months old, the molecular prevalence of E. bieneusi was 10% (1/10). Surprisingly, remaining cattle > 2 years old (n = 11) were found to be E. bieneusi-negative. BLAST and phylogenetic analyses revealed type IV as well as 11 new genotypes designated as NG1 to NG11.

CONCLUSION

These findings point out that cattle and farms are important sources for the transmission of E. bieneusi spores to humans or animals.

First report of Blastocystis sp. and Enterocytozoon bieneusi in raptors

Introduction

Blastocystis sp. and Enterocytozoon bieneusi are common zoonotic pathogens threatening human and animal health. These parasites are widely distributed in birds, and substantial research on their prevalence has been conducted. However, no studies on Blastocystis sp. and E. bieneusi in raptors exist.

Methods

The present study collected 335 fecal samples from raptors in Changdao, China. The prevalence and genotypes of Blastocystis sp. and E. bieneusi were determined through amplification of SSU rRNA and ITS gene. Phylogenetic analysis was performed using MEGA 11 with the neighbor-joining method (Kimura 2-parameter model, 1000 replicate).

Results

The overall infection rates of Blastocystis sp. and E. bieneusi in raptors were 1.19% (4/335) and 1.79% (6/335), respecttively. Among them, the highest infection rate of Blastocystis sp. was observed in Accipiter nisus (3.85%, 1/26), while Buteo japonicus showed the highest infection rate of E. bieneusi (33.33%, 1/3), followed by Asio otus (7.69%, 1/13). This study identified two Blastocystis sp. subtypes: ST3 and ST10 in raptors for the first time. Regarding E. bieneusi in raptors, we identified four genotypes: CHN-F1, HND-III, BEB6, and HLJD-I. Among these, BEB6 and CHN-F1 are notable for their zoonotic potential and the risk of waterborne outbreaks.

Discussion

These findings suggest that raptors may be potential transmitters of Blastocystis sp. and E. bieneusi to humans and other animals, as well as sources of water contamination. This study fills a gap in the research on Blastocystis sp. and E. bieneusi in raptors and is important for public health safety.

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.

Molecular investigation of Blastocystis in children and calves in Bangladesh

BACKGROUND

Blastocystis, a widely distributed zoonotic protozoan infecting both humans and numerous animals, remains poorly understood with its potential medical and veterinary significance. This study examined the molecular occurrence and genetic variation of Blastocystis in children and calves in Bangladesh to explore cross-species transmission and disease burden.

METHODS

In total, 998 DNA samples were investigated, comprising 299 stool DNA from children and 699 fecal DNA from calves, using polymerase chain reaction and sequencing of the small subunit ribosomal RNA (SSU rRNA) gene.

RESULTS

This study detected Blastocystis in 5.35% of the children and 14.74% of the calves. While slight variations in occurrence rates were observed across different study variables, none were statistically significant. The occurrence was highest among children under 5 years and calves aged 1-3 months. Regarding breed, the Holstein Friesian cross and the Jersey cross exhibited higher rates of infection. Conversely, occurrences were lower among children and calves in Gazipur district. The remaining parameters displayed nearly equivalent percentages of Blastocystis. The subtypes identified in children included ST1, ST3, and ST4, with ST1 comprising 50% of them. ST3 and ST4 were also found in calves, alongside ST10 (55.34%) being the most prevalent. Other subtypes found in calves were ST14, ST21, and ST24-ST26.

CONCLUSIONS

This study found that Blastocystis is more common in calves than in children in Bangladesh, with genetic diversity of nine subtypes. The common occurrence of identical variants of two subtypes in both populations suggests potential zoonotic transmission, highlighting the necessity for further molecular investigations and comprehensive measures within the One Health framework to mitigate public health risks.

Wild rodents in three provinces of China exhibit a wide range of Enterocytozoon bieneusi diversity

Introduction

Enterocytozoon bieneusi is one of the most important zoonotic pathogens, responsible for nearly 90% of human infections. Its host spectrum is broad in China, encompassing humans, non-human primates, domestic animals, wildlife, and wastewater. Wild rodents have the potential to act as carriers of E. bieneusi, facilitating the parasite's transmission to humans and domestic animals.

Methods

The present study involved the collection of 344 wild rodents, representing nine species, from three provinces in China. The prevalence and genotypes of E. bieneusi were determined through amplification of the ITS gene. Evolutionary analysis was conducted using Mega 5.0 with the neighbor-joining method (Kimura 2-parameter model, 1,000 replicates).

Results

Among the sampled wild rodents, 41 (11.92%) were tested positive for E. bieneusi. Rattus flavipectus exhibited the highest prevalence (11/39), while Bandicota indica and Rattus rattus sladeni showed no infections (0/39 and 0/5, respectively), highlighting significant differences. Environmental factors strongly influenced E. bieneusi infection; rodents residing in lake beaches (10.27%, 15/146) and fields (19.95%, 18/95) were more susceptible compared to those in mountainous areas (7.77%, 8/103). The study identified four known genotypes (D, Type IV, SDD5, PigEBITS7) and five novel genotypes (HNRV-1 to HNRV-3, GXRL-1, GXRL-2) in the investigated wild rodents, with Genotype D exhibiting the highest prevalence.

Discussion

Remarkably, this study reports the presence of E. bieneusi, R. flavipectus, M. fortis, A. agrarius, R. losea, and N. lotipes for the first time. These findings underscore the common occurrence of E. bieneusi infection in wild rodents in China, highlighting its diverse nature and significant potential for zoonotic transmission. Hence, it is imperative to conduct a comprehensive epidemiological investigation of rodent infection with E. bieneusi, particularly focusing on wild rodents that are closely associated with humans. Additionally, developing appropriate measures and monitoring strategies to minimize the risk of infection is essential.

Investigating Enterocytozoon bieneusi in pigs farmed in Zhejiang Province, China: Occurrence, genotype identification, evolutionary analysis, and zoonotic risk assessment

Enterocytozoon bieneusi is a widespread intracellular fungus that can infect both humans and animals, making it a significant zoonotic threat. In the current study, a total of 208 fecal samples were assayed to investigate the prevalence of E. bieneusi in pigs reared in Zhejiang Province, China. Employing polymerase chain reaction (PCR) amplification techniques specifically designed to target the internal transcribed spacer (ITS) region of the small subunit ribosomal RNA (rRNA) gene, the results revealed that 78 samples (37.5 %) tested positive for the presence of E. bieneusi. A total of 19 different genotypes of E. bieneusi were detected. Nine of these genotypes were already known: EbpC (n = 36), KIN-1 (n = 10), PigEbITS7 (n = 8), EbpA (n = 6), Henan III (n = 3), PigEbITS5 (n = 2), Henan-IV (n = 1), EbpD (n = 1), and TypeIV (n = 1), and 10 were novel: ZJP-I to ZJP-X (one each). The present investigation revealed that all the nine known genotypes identified in pigs here, have also been previously discovered in humans. Additionally, the novel genotypes of E. bieneusi discovered here were all classified as belonging to Group 1. These findings suggest the potential for cross-species transmission between humans and pigs.

Molecular characterization and zoonotic risk assessment of Cryptosporidium spp. in children and calves in Bangladesh

Cryptosporidium is a gastro-intestinal protozoan parasite that has been found to infect both humans and livestock. This study investigated the parasite in 998 fecal samples from Bangladeshi children (n = 299) and calves (n = 699) to determine its prevalence, genetic variation, and zoonotic importance. The nested PCR and sequencing of the SSU rRNA gene in the samples showed a Cryptosporidium infection rate of 2.3% (7/299) in children and 15.7% (110/699) in calves. Statistical analysis revealed insignificant variations in Cryptosporidium infections among children across age, gender, and study area, while in calves, the infection rate significantly differed based on location and breed. Genotyping of seven human isolates of Cryptosporidium confirmed C. hominis (n = 5) and C. parvum (n = 2). After characterizing 110 Cryptosporidium isolates from calves, C. andersoni (n = 55), C. ryanae (n = 29), C. bovis (n = 14), C. parvum (n = 10), C. ubiquitum (n = 1), and C. occultus (n = 1) were identified. Cryptosporidium hominis and C. parvum-positive samples were further subjected to nested PCR and sequencing of the glycoprotein 60 (gp60) gene for subtyping. Four C. hominis subtypes (IaA19R3, IaA23R3, IbA9G3, and IdA15G1) and one C. parvum subtype (IIdA15G1) were observed. In conclusion, Cryptosporidium was prevalent in calves but less common in children in the study locations, and the presence of zoonotic Cryptosporidium species and subtypes in calves raises concerns regarding zoonotic transmission to humans.

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.

Detection and genotyping of zoonotic microsporidia in the endangered Iberian lynx (Lynx pardinus)

Microsporidia is a diverse group of obligate, intracellular, and spore-forming parasites that infect a wide range of animals. Among them, Enterocytozoon bieneusi and Encephalitozoon spp. are the most frequently reported species in humans. Limited information is available about the presence and molecular diversity of microsporidian species in the endangered Iberian lynx (Lynx pardinus). Presence of Enterocytozoon bieneusi and Encephalitozoon spp. was investigated by molecular methods in wild and captive Iberian lynxes from Spain. Overall, E. bieneusi was detected in 3.2% (8/251) of the animals examined. None of the samples tested were positive for Encephalitozoon spp. Four known (D, EbfelA, PigEBITS7, and Type IV) and a novel (named as LynxSpEb1) E. bieneusi genotypes were identified. All the genotypes found belonged to the zoonotic Group 1 of E. bieneusi. This study provides the first genotyping data of E. bieneusi in Iberian lynx in Spain. Our result indicate that the Iberian lynx does not seem to play a relevant role in the epidemiology of Encephalitozoon spp., and that this endangered felid is likely acting as spillover host rather than a true reservoir of E. bieneusi. Additional studies should be conducted to assess the impact of this parasite in the health status of the endangered Iberian lynx.

Molecular epidemiology of Enterocytozoon bieneusi from foxes and raccoon dogs in the Henan and Hebei provinces in China

BACKGROUND

Enterocytozoon bieneusi is a zoonotic pathogen widely distributed in animals and humans. It can cause diarrhea and even death in immunocompromised hosts. Approximately 800 internal transcribed spacer (ITS) genotypes have been identified in E. bieneusi. Farmed foxes and raccoon dogs are closely associated to humans and might be the reservoir of E. bieneusi which is known to have zoonotic potential. However, there are only a few studies about E. bieneusi genotype identification and epidemiological survey in foxes and raccoon dogs in Henan and Hebei province. Thus, the present study investigated the infection rates and genotypes of E. bieneusi in farmed foxes and raccoon dogs in the Henan and Hebei provinces.

RESULT

A total of 704 and 884 fecal specimens were collected from foxes and raccoon dogs, respectively. Nested PCR was conducted based on ITS of ribosomal RNA (rRNA), and then multilocus sequence typing (MLST) was conducted to analyze the genotypes. The result showed that infection rates of E. bieneusi in foxes and raccoon dogs were 18.32% and 5.54%, respectively. Ten E. bieneusi genotypes with zoonotic potential (NCF2, NCF3, D, EbpC, CHN-DC1, SCF2, CHN-F1, Type IV, BEB4, and BEB6) were identified in foxes and raccoon dogs. Totally 178 ITS-positive DNA specimens were identified from foxes and raccoon dogs and these specimens were then subjected to MLST analysis. In the MLST analysis, 12, 2, 7 and 8 genotypes were identified in at the mini-/ micro-satellite loci MS1, MS3, MS4 and MS7, respectively. A total of 14 multilocus genotypes were generated using ClustalX 2.1 software. Overall, the present study evaluated the infection of E. bieneusi in foxes and raccoon dogs in the Henan and Hebei province, and investigated the zoonotic potential of the E. bieneusi in foxes and raccoon dogs.

CONCLUSIONS

These findings expand the geographic distribution information of E. bieneusi' host in China and was helpful in preventing against the infection of E. bieneusi with zoonotic potential in foxes and raccoon dogs.

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.

Potential Zoonotic Transmission of Giardia duodenalis between Children and Calves in Bangladesh

Giardia duodenalis is a zoonotic protozoan parasite that causes gastrointestinal illness in humans and livestock. We studied the genetic diversity of G. duodenalis in children and calves from Bangladesh to determine its zoonotic potential. Fecal samples collected from children (299) and calves (699) were screened with nested PCR with primers targeting the ssu rRNA gene for G. duodenalis. Positive samples were further multilocus genotyped using the β-giardin (bg), glutamate dehydrogenase (gdh), and triose phosphate isomerase (tpi) genes. The overall infection rate of G. duodenalis was 21.1% (63/299) in children and 5.7% (40/699) in calves. There were no significant differences in infection with G. duodenalis among age groups, sex, and study areas in children and calves. Multilocus genotyping (MLG) of human G. duodenalis identified zoonotic assemblages A (34.0%, 18/53) and B (50.9%, 27/53) and a so-called ruminant-specific assemblage E (11.3%, 6/53), as well as two mixed assemblages, B/D (1/53) and B/E (1/53). Assemblage E predominated in calves (82.3%, 28/34), followed by assemblages A (11.8%, 4/34) and B (5.9%, 2/34). Overall, zoonotic assemblages A, B, and E were found in 6.0% (18/299), 9.0% (27/299), and 2.0% (6/299) of the children's stool samples, respectively, and 0.6% (4/699), 0.3% (2/699), and 4.0% (28/699) of the calf fecal samples, respectively. Although there was a difference in the distribution of subassemblages in humans (mostly AII) and calves (mostly AI), the zoonotic assemblages A, B, and E present in both children and calves suggest the potential for zoonotic transmission of G. duodenalis. This molecular study highlights the fact that G. duodenalis infections were common in the study areas, with potential zoonotic transmission between children and calves, implying that cattle might play a role in G. duodenalis zoonotic transmission.

Molecular Detection and Genotyping of Enterocytozoon bieneusi in Beef Cattle in Shanxi Province, North China

Enterocytozoon bieneusi is an intracellular pathogen that can parasitize humans and a variety of animals. The infection of E. bieneusi in most hosts is asymptomatic, but in immunocompromised individuals, it can lead to serious complications such as acute diarrhea, dehydration, and even death. However, no data on the prevalence and genotyping of E. bieneusi in beef cattle in Shanxi province are currently available. In this study, a total of 401 fecal samples were collected from beef cattle in farms from two representative counties—Qi county and Jishan county—in Shanxi province, north China. Nested PCR was applied to determine the prevalence and genotypes of E. bieneusi by amplifying and sequencing the internal transcribed spacer (ITS) regions of the rRNA gene. A total of 90 out of 401 samples were detected as E. bieneusi-positive, with 22.44% overall prevalence of E. bieneusi in beef cattle in Shanxi province. The highest prevalence of E. bieneusi was detected in calves (28.67%, 41/143) and male beef cattle (28.13%, 54/192). Statistical analysis revealed that the prevalence of E. bieneusi was significantly associated with gender and age factors (p < 0.05), but without any statistical difference among regions. Moreover, six known E. bieneusi genotypes (BEB4, BEB6, BEB8, J, I, and PigSpEb2) and two novel genotypes (designated CSC1 and CSC2) were identified by analysis of ITS sequences, and genotype I was the predominant genotype in these two counties. Phylogenetic analysis showed that five known genotypes and two novel genotypes were clustered into Group 2, but PigSpEb2 belonged to Group 1. To our knowledge, the present study demonstrated the presence and identified genotypes of E. bieneusi in beef cattle in Shanxi province for the first time, extending the data on prevalence and genotypes of E. bieneusi in beef cattle and providing baseline data for executing intervention measures to control it in the study regions.

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.