Occurrence and Genotypic Identification of Blastocystis spp., Enterocytozoon bieneusi, and Giardia duodenalis in Leizhou Black Goats in Zhanjiang City, Guangdong Province, China

Establishment and preliminary application of PCR-RFLP genotyping method for Giardia duodenalis in goats

BACKGROUND

Giardia duodenalis (G. duodenalis) is a globally distributed zoonotic protozoan that parasitizes the small intestines of humans and various mammals, such as goats and sheep. The objective of this study was to establish a convenient, accurate, and specific method based on restriction fragment length polymorphism (RFLP) for genotyping assemblages A, B and E of G. duodenalis in goats. The β-giardin gene was amplified using primer pairs bgF1, bgR1, bgF2 and bgR2 by nested PCR. The PCR products were digested with the restriction enzymes Hinf I and Bgl I. The established PCR-RFLP method was used to detect and analyze the genetic subtypes of G. duodenalis in 130 fecal samples from goats and compared simultaneously with microscopic examination and nucleic acid sequencing for G. duodenalis.

RESULTS

Genetic sequencing confirmed that the PCR-RFLP method accurately distinguished G. duodenalis assemblages A, B and E, as well as different combinations of mixed infections of these three assemblages. Among the 130 samples tested by PCR-RFLP, a total of 26 samples (20.00%) tested positive for G. duodenalis, a higher sensitivity than microscopic examination at 13.85% (18/130). Sequence alignment analysis revealed that among the 26 PCR-positive samples, two were identified as assemblage AI, while the remaining 24 were identified as assemblage E or E12.

CONCLUSIONS

This study established an accurate, efficient and rapid PCR-RFLP genotyping method using the bg sequence of G. duodenalis, enabling accurate identification and effective differentiation of goat-derived G. duodenalis assemblages without requiring sequencing.

Occurrence and Genotypic Identification of Blastocystis spp. and Enterocytozoon bieneusi in Bamaxiang Pigs in Bama Yao Autonomous County of Guangxi Province, China

Blastocystis spp. and Enterocytozoon bieneusi are common intestinal pathogens capable of infecting both humans and animals, which lead to severe diarrhea and other intestinal diseases, posing a threat to public health. The Bamaxiang pig, a specialty of Bama Yao Autonomous County in Guangxi Province, China, is an important local breed in the regional pork market and an excellent model animal for biomedical research. Currently, no data is available on the prevalence or genotype distribution of these pathogens in Bamaxiang pigs. This study aimed to determine the prevalence and genetic characteristics of Blastocystis spp. and E. bieneusi in three Bamaxiang pig farms located in Bama Yao Autonomous County, using molecular techniques based on the small subunit ribosomal RNA (SSU rRNA) gene fragment of Blastocystis spp. and the internal transcribed spacer (ITS) region of E. bieneusi. All positive PCR products from the 311 fecal samples were sequenced to identify the species and genotypes of these organisms. The overall infection rates of Blastocystis spp. and E. bieneusi were 34.08% (106/311) and 18.32% (57/311), respectively. Three subtypes of Blastocystis spp. were detected: ST1 (n = 8), ST3 (n = 3), and ST5 (n = 95). Among them, zoonotic ST5 was the dominant genotype, accounting for 89.62% (95/106) of strains, followed by the genotypes ST1 (7.54%, 8/106) and ST3 (2.83%, 3/106). Two genotypes of E. bieneusi were detected: EbpC (n = 52) and CHG23 (n = 5), with EbpC being the dominant genotype. The human-pathogenic subtypes (ST1, ST3, and ST5) and genotypes (EbpC, CHG23) that were observed in this study indicate a potential threat to public health. Our findings offer basic information for preventing and controlling these zoonotic pathogens in the study area. Additional investigations are necessary to better understand their genetic characteristics and zoonotic potential within Guangxi Province.

Molecular prevalence and genotype identification of Enterocytozoon bieneusi in cattle and goats from Zhejiang Province, China

Introduction

Enterocytozoon bieneusi (E. bieneusi) is a widespread intracellular fungi that poses a significant zoonotic threat due to its infectivity toward both humans and animals.

Methods

To evaluate the zoonotic transmission potential of this fungi, a molecular investigation was undertaken on E. bieneusi in cattle and goats reared across multiple cities in Zhejiang Province, China. A total of 651 fresh samples were collected, consisting of 265 cattle and 386 goats. The presence of E. bieneusi was determined by PCR amplification and sequencing analysis of the internal transcribed spacer (ITS) region of the small subunit ribosomal RNA (SSU rRNA) gene in all collected samples.

Results

The results revealed that 17.1% (111/859) of the animals were afflicted with E. bieneusi, cattle having a prevalence of 14.0% (37/265) and goats displaying a higher rate of 19.2% (74/386). Seventeen E. bieneusi genotypes were identified, including 10 known, CHG5 (n = 30), CHG3 (n = 21), I (n = 14), J (n = 12), CHG2 (n = 11), COS-II (n = 8), D (n = 4), CHG19 (n = 2), ETMK5 (n = 1), and Henan III (n = 1), and seven novel, ZJG-I to ZJG-VI and ZJN-I (one each) genotypes.

Discussion

These findings indicate widespread infection of E. bieneusi among the surveyed animals, thereby raising concerns about zoonotic genotypes that could pose potential threats to public health. Furthermore, the identification of novel genotypes of E. bieneusi offers valuable insights into the genetic diversity of this pathogen.

A Multiplex PCR Assay for Simultaneous Detection of Giardia duodenalis, Cryptosporidium parvum, Blastocystis spp. and Enterocytozoon bieneusi in Goats

Giardia duodenalis, Cryptosporidium parvum, Blastocystis spp. and Enterocytozoon bieneusi are four common zoonotic parasites associated with severe diarrhea and enteric diseases. In this study, we developed a multiplex PCR assay for the simultaneous detection of these four zoonotic protozoans in goat stool samples and assessed its detection efficiency. Specific primers were designed from conserved gene sequences retrieved from GenBank, and the PCR conditions were optimized. Genomic DNA from 130 samples was subjected to both single-target PCR and multiplex PCR. The multiplex PCR assay successfully amplified specific gene fragments (G. duodenalis, 1400 bp; C. parvum, 755 bp; Blastocystis spp., 573 bp; E. bieneusi, 314 bp). The assay sensitivity was ≥102 copies of pathogenic DNA clones with high specificity confirmed by negative results for other intestinal parasites. The detection rates were 23.08% (30/130) for G. duodenalis, 24.62% (32/130) for C. parvum, 41.54% (54/130) for Blastocystis spp., and 12.31% (16/130) for E. bieneusi, matching the single-target PCR results. The sensitivity and predictive values were 100.00%. This multiplex PCR provided a rapid, sensitive, specific, and cost-effective approach for detecting these four parasites. It also provided essential technical support for the rapid detection and epidemiological investigation of G. duodenalis, C. parvum, Blastocystis spp., and E. bieneusi infections in goat fecal samples.

Large-Scale Molecular Epidemiological Survey of Blastocystis sp. among Herbivores in Egypt and Assessment of Potential Zoonotic Risk

Given the proven zoonotic potential of the intestinal protozoan Blastocystis sp., a fast-growing number of surveys are being conducted to identify potential animal reservoirs for transmission of the parasite. Nevertheless, few epidemiological studies have been conducted on farmed animals in Egypt. Therefore, a total of 1089 fecal samples were collected from herbivores (sheep, goats, camels, horses, and rabbits) in six Egyptian governorates (Dakahlia, Gharbia, Kafr El Sheikh, Giza, Aswan, and Sharqia). Samples were screened for the presence of Blastocystis sp. by real-time PCR followed by sequencing of positive PCR products and phylogenetic analysis for subtyping of the isolates. Overall, Blastocystis sp. was identified in 37.6% of the samples, with significant differences in frequency between animal groups (sheep, 65.5%; camels, 62.2%; goats, 36.0%; rabbits, 10.1%; horses, 3.3%). Mixed infections were reported in 35.7% of the Blastocystis sp.-positive samples. A wide range of subtypes (STs) with varying frequency were identified from single infections in ruminants including sheep (ST1-ST3, ST5, ST10, ST14, ST21, ST24, ST26, and ST40), goats (ST1, ST3, ST5, ST10, ST26, ST40, ST43, and ST44), and camels (ST3, ST10, ST21, ST24-ST26, ST30, and ST44). Most of them overlapped across these animal groups, highlighting their adaptation to ruminant hosts. In other herbivores, only three and two STs were evidenced in rabbits (ST1-ST3) and horses (ST3 and ST44), respectively. The greater occurrence and wider genetic diversity of parasite isolates among ruminants, in contrast to other herbivores, strongly suggested that dietary habits likely played a significant role in influencing both the colonization rates of Blastocystis sp. and ST preference. Of all the isolates subtyped herein, 66.3% were reported as potentially zoonotic, emphasizing the significant role these animal groups may play in transmitting the parasite to humans. These findings also expand our knowledge on the prevalence, genetic diversity, host specificity, and zoonotic potential of Blastocystis sp. in herbivores.

Prevalence and Genetic Characterization of Giardia duodenalis and Blastocystis spp. in Black Goats in Shanxi Province, North China: From a Public Health Perspective

Blastocystis spp. and Giardia duodenalis are two prevalent zoonotic intestinal parasites that can cause severe diarrhea and intestinal diseases in humans and many animals. Black goat (Capra hircus) farming is increasingly important in China due to the remarkable adaptability, high reproductive performance, rapid growth rate, and significant economic value of black goats. A number of studies have indicated that black goats are the potential reservoir of multiple zoonotic protozoans in China; however, the prevalence and zoonotic status of G. duodenalis and Blastocystis spp. in black goats in Shanxi Province is still unknown. Thus, a total of 1200 fecal samples of black goats were collected from several representative regions at different altitudes in Shanxi Province and were examined for the presence and genotypes of G. duodenallis and Blastocystis spp. by amplifying the beta-giardin (bg), glutamate dehydrogenase (gdh), and triosephosphate isomerase (tpi) loci of G. duodenalis and SSU rRNA of Blastocystis spp. using PCR and sequence analysis methods, respectively. The overall prevalence of G. duodenalis and Blastocystis spp. in black goats in Shanxi Province were 7.5% and 3.5%, respectively. Two assemblages (B and E) of G. duodenalis and four subtypes (ST5, ST10, ST14, and ST30) of Blastocystis spp. were identified, with assemblage E and ST10 as the prevalent genotype and subtype in black goats, respectively. One novel multilocus genotype (MLG) was identified in MLG-E and was designated as MLG-E12. For both G. duodenalis and Blastocystis spp., the prevalence was significantly related to the region and age groups (p < 0.05). This is the first report on the prevalence of G. duodenalis and Blastocystis spp. in black goats in Shanxi Province. These results not only provide baseline data for the prevention and control of both parasites in black goats in Shanxi Province, but also enhance our understanding of the genetic composition and zoonotic potential of these two parasites.

Molecular detection and characterization of Blastocystis in herbivore livestock species in Portugal

Blastocystis is a ubiquitous intestinal protist in humans and animals worldwide. The traditional livestock free-roaming raising system in rural communities increases the risk of infection with contact with a wider range of pathogens transmitted via the faecal-oral route associated with that wildlife-livestock-human interface. However, no studies have been conducted to determine the occurrence and subtype distribution of Blastocystis in livestock in Portugal. Here, we collected 180 faecal samples from herbivore livestock (cattle, goats, horses, and sheep) in different regions of the country to investigate Blastocystis prevalence and subtype diversity using PCR and next-generation amplicon sequencing. Blastocystis was present in 40.6% (73/180; 95% CI: 33.31-48.11) of the samples (goats, 81.0%; sheep, 60.9%; cattle, 32.2%). None of the horse samples were Blastocystis-positive. Eighteen subtypes were detected (ST1-ST3, ST5-ST7, ST10, ST13, ST14, ST21, ST23-ST26, ST30, ST42-ST44). Mixed infections were detected in 97.3% of the Blastocystis-positive samples. Potentially zoonotic subtypes were identified in 75.0%, 96.4%, and 100% of the Blastocystis-positive specimens collected from cattle, sheep, and goats, respectively. These results demonstrate that cattle, sheep, and goats harbour a high diversity of Blastocystis subtypes in the study regions. Importantly, our data provide novel molecular evidence strongly suggesting that some Blastocystis STs/ST subgroups may have differential host specificity.

Occurrence and Phylogenetic Analysis of Zoonotic Enteropathogenic Protist Parasites in Asymptomatic Domestic Ruminants from Portugal

Enteropathogenic parasites are of significant concern for public health due to their zoonotic potential and their impact on human and animal health. In this study, we investigated their occurrence and characterized these enteropathogens in asymptomatic domestic ruminants from Portugal. A total of 302 stool samples were collected from cattle (n = 166), sheep (n = 73), and goats (n = 63) in various regions of Portugal and tested for Cryptosporidium spp., Giardia duodenalis, Enterocytozoon bieneusi, Blastocystis sp., and Balantioides coli by PCR. The occurrence of Cryptosporidium spp. was found to be 12.7% (8/63, 95% confidence interval [CI]: 5.65-23.5) in goats; however, no sample was found to be positive for Cryptosporidium spp. in cattle and sheep. For E. bieneusi, 6.35% (4/63; 95%CI: 1.76-15.47) of goats were found to be positive; however, no cattle or sheep were found to be positive. Blastocystis sp. was found in sheep (9.59%; 7/73; 95% [CI]: 0.394-18.76) and goats (12.70%; 8/63; 95% [CI]: 5.65-23.50) but none was found in cattle. No positive results for G. duodenalis or B. coli were detected in this study. This study provides essential baseline information for understanding the silent shedding and epidemiology of these enteropathogens in Portugal, contributing to overall livestock health and related occupational safety. Raising awareness among consumers, veterinarians, and farm owners is crucial to minimize the risk of transmission and promote effective disease control strategies.