Multilocus genotyping of Giardia duodenalis in Bactrian camels (Camelus bactrianus) in China

Prevalence, genetic diversity, and zoonotic potential of Giardia duodenalis in New and Old World Camelids: A comparative systematic review and meta-analysis

This study aimed to review and analyze the prevalence, genetic diversity, and zoonotic potential of Giardia duodenalis in New World Camelids (NWCs) and Old World Camelids (OWCs), highlighting geographic and host-related variations. The statistical analyses were conducted using CMA software to estimate pooled prevalence rates. Heterogeneity was evaluated with the I² statistic, and sensitivity analysis tested pooled prevalence after removing certain studies. Meta-regression examined the association between G. duodenalis prevalence in camelids and factors like publication year and sample size. Subgroup analyses investigated prevalence variations based on countries, continents, WHO regions, publication years, diagnostic methods, and sample sizes. A total of 22 studies/23 datasets were included, with eight on NWCs and 15 on OWCs, covering 5008 camelids across nine countries. The weighted G. duodenalis prevalence in camelids was 8.7 % (95 % CI: 5.6-13.3), with NWCs at 10.3 % (95 % CI: 3-29.7) and OWCs at 9.1 % (95 % CI: 6.7-12.2). Geographical analyses revealed the highest prevalence of G. duodenalis in South America (40.4 %) and the AMR WHO region (10.8 %), with notable rates in Peru (40.4 %) and Iraq (11.9 %). Sensitivity analysis showed that prevalence rates remain robust, unaffected by study exclusions. Neither the year of study nor sample size influenced infection rates in camelids. The identification of zoonotic assemblages A and E, and zoonotic sub-assemblage AI in camelids, is of public health significance. These insights enhance our understanding of G. duodenalis epidemiology in camelids, underscoring the need for ongoing surveillance and research regarding their effects on human and animal health.

Global prevalence of Giardia infection in nonhuman mammalian hosts: A systematic review and meta-analysis of five million animals

BACKGROUND

Members of the Giardia genus are zoonotic protozoan parasites that cause giardiasis, a diarrheal disease of public and veterinary health concern, in a wide range of mammal hosts, including humans.

METHODOLOGY

We conducted a systematic review and meta-analysis to provide evidence-based data on the worldwide prevalence of Giardia infection in nonhuman mammals that can be used as scientific foundation for further studies. We searched public databases using specific keywords to identify relevant publications from 1980 to 2023. We computed the pooled prevalence estimates utilizing a random-effects meta-analysis model. Animals were stratified according to their taxonomic hierarchy, as well as ecological and biological factors. We investigated the influence of predetermined variables on prevalence estimates and heterogeneity through subgroup and meta-regression analyses. We conducted phylogenetic analysis to examine the evolutionary relationships among different assemblages of G. duodenalis.

PRINCIPAL FINDINGS

The study included 861 studies (1,632 datasets) involving 4,917,663 animals from 327 species, 203 genera, 67 families, and 14 orders from 89 countries. The global pooled prevalence of Giardia infection in nonhuman mammals was estimated at 13.6% (95% CI: 13.4-13.8), with the highest rates observed in Rodentia (28.0%) and Artiodactyla (17.0%). Herbivorous (17.0%), semiaquatic (29.0%), and wild (19.0%) animals showed higher prevalence rates. A decreasing prevalence trend was observed over time (β = -0.1036477, 95% CI -0.1557359 to -0.0515595, p < 0.000). Among 16,479 G. duodenalis isolates, 15,999 mono-infections belonging to eight (A-H) assemblages were identified. Assemblage E was the predominant genotype (53.7%), followed by assemblages A (18.1%), B (14.1%), D (6.4%), C (5.6%), F (1.4%), G (0.6%), and H (0.1%). The highest G. duodenalis genetic diversity was found in cattle (n = 7,651, where six assemblages including A (13.6%), B (3.1%), C (0.2%), D (0.1%), E (81.7%), and mixed infections (1.2%) were identified.

CONCLUSIONS/SIGNIFICANCE

Domestic mammals are significant contributors to the environmental contamination with Giardia cysts, emphasizing the importance of implementing good management practices and appropriate control measures. The widespread presence of Giardia in wildlife suggests that free-living animals can potentially act as sources of the infection to livestock and even humans through overlapping of sylvatic and domestic transmission cycles of the parasite.

Molecular characterization and associated risk factors of zoonotic cryptosporidiosis in bovine calves and humans in Menoufia governorate, Egypt

Background

Cryptosporidium is a common intestine anthroponotic protozoan parasite that affects humans and other animals all over the world. Many different kinds of vertebrates have their gastrointestinal epithelium infected by the ubiquitous, obligatory parasites of Cryptosporidium spp. In humans, those with weakened immune systems, including those with acronym for acquired immunodeficiency syndrome, are most affected. Particularly prevalent in developing nations, cryptosporidiosis poses further difficulties for the underfunded public health system. Humans frequently harbor a number of Cryptosporidium species, whose prevalence varies according to socioeconomic level and level of animal husbandry.

Aim

The present study was conducted to ascertain the prevalence of Cryptosporidium bovis and associated relevant risk factors of contracting cryptosporidiosis in calves and humans in Menoufia governorate, Egypt. In addition, a phylogenetic analysis was performed for additional molecular identification in order to study the evolution of the parasite and comprehend the mechanism of cryptosporidiosis evolution in the selected governorate.

Methods

Using direct wet smear, sedimentation technique, simple fecal flotation technique, and modified Ziehl-Neelsen staining technique, the parasitological analysis was conducted on fecal samples from 156 diarrheic calves and 125 humans in Menoufia governorate; polymerase chain reaction and phylogenetic analysis were further used.

Results

Based on the microscopical examination, the prevalence of Cryptosporidium was 19.2% in humans and 64.1% in calves.‎ A statistical correlation was found between the prevalence of cryptosporidiosis in calves of American breeds, their early age, and the predominant warm climate. In the analyzed calves, the study was unable to detect any statistically significant difference between the type of diarrhea and increased infection. In terms of people, the study found no significant correlation between the sex of the people under inquiry, whereas a significant association was revealed among contracting cryptosporidiosis in young people, during warm climates, and among diarrhea sufferers. PCR application produced a 4% positive result. Following phylogenetic analysis, the Cryptosporidium parvum species was identified from the PCR-positive samples.

Conclusion

Different transmission trajectories were proposed by cluster analysis, and it was possible to take into consideration the role of calves for the zoonotic transmission of cryptosporidiosis to humans.‎.

Molecular characterization and associated risk factors of zoonotic cryptosporidiosis in bovine calves and humans in Menoufia governorate, Egypt

Background

Cryptosporidium is a common intestine anthroponotic protozoan parasite that affects humans and other animals all over the world. Many different kinds of vertebrates have their gastrointestinal epithelium infected by the ubiquitous, obligatory parasites of Cryptosporidium spp. In humans, those with weakened immune systems, including those with acronym for acquired immunodeficiency syndrome, are most affected. Particularly prevalent in developing nations, cryptosporidiosis poses further difficulties for the underfunded public health system. Humans frequently harbor a number of Cryptosporidium species, whose prevalence varies according to socioeconomic level and level of animal husbandry.

Aim

The present study was conducted to ascertain the prevalence of Cryptosporidium bovis and associated relevant risk factors of contracting cryptosporidiosis in calves and humans in Menoufia governorate, Egypt. In addition, a phylogenetic analysis was performed for additional molecular identification in order to study the evolution of the parasite and comprehend the mechanism of cryptosporidiosis evolution in the selected governorate.

Methods

Using direct wet smear, sedimentation technique, simple fecal flotation technique, and modified Ziehl-Neelsen staining technique, the parasitological analysis was conducted on fecal samples from 156 diarrheic calves and 125 humans in Menoufia governorate; polymerase chain reaction and phylogenetic analysis were further used.

Results

Based on the microscopical examination, the prevalence of Cryptosporidium was 19.2% in humans and 64.1% in calves.‎ A statistical correlation was found between the prevalence of cryptosporidiosis in calves of American breeds, their early age, and the predominant warm climate. In the analyzed calves, the study was unable to detect any statistically significant difference between the type of diarrhea and increased infection. In terms of people, the study found no significant correlation between the sex of the people under inquiry, whereas a significant association was revealed among contracting cryptosporidiosis in young people, during warm climates, and among diarrhea sufferers. PCR application produced a 4% positive result. Following phylogenetic analysis, the Cryptosporidium parvum species was identified from the PCR-positive samples.

Conclusion

Different transmission trajectories were proposed by cluster analysis, and it was possible to take into consideration the role of calves for the zoonotic transmission of cryptosporidiosis to humans.‎.

Prevalence and Associated Risk Factors of Helminth Infections in the Digestive Tract of Camels in Xinjiang, China

Camels, vital to economies in Asia, Africa, and the Arabian Peninsula, have been domesticated for over 4000 years. They thrive in arid regions like Xinjiang, China, but face challenges from internal and external parasites, particularly gastrointestinal parasites, which impact health, meat and milk quality, and production efficiency. This study investigates the prevalence of gastrointestinal helminth infections in camels from five major regions in Xinjiang. We collected 435 fresh fecal samples and used the saturated saline flotation method and McMaster's method for detection. Molecular examination followed. The overall prevalence was 18.2% (95% confidence interval [CI]: 14.7-22.2%), with Urumqi showing the highest prevalence (29%, 95% CI: 23.4-35.1%) compared to other regions (odds ratio [OR]: 4.62, 95% CI: 2.63-8.41%). Younger camels (≤3 years old) were more likely infected by the parasites after adjusting for the region differences (OR: 10.53, 5.12-24.65%). However, we found no evidence that the prevalence was different between male and female camels. PCR analysis identified Trichostrongylus spp., Chabertia ovina, and Haemonchus contortus as predominant parasites, with observed co-infections indicating a complex parasitic landscape. The findings provide essential epidemiological data for effective parasite control strategies.

Prevalence and molecular characterization of Giardia duodenalis in dairy cattle in Central Inner Mongolia, Northern China

Giardia duodenalis is a gastrointestinal protozoan ubiquitous in nature. It is a confirmed zoonotic pathogen, and cattle are considered a source of giardiasis outbreaks in humans. This study aimed to evaluate the prevalence and multilocus genotype (MLG) of G. duodenalis in dairy cattle in Central Inner Mongolia. This study was based on the small subunit ribosomal RNA (SSU rRNA), glutamate dehydrogenase (gdh), triosephosphate isomerase (tpi), and beta-giardin (bg) genes of G. duodenalis. DNA extraction, polymerase chain reaction (PCR), and sequence analysis were performed on 505 dairy cattle fecal samples collected in 2021 from six sampling sites and four age groups in Central Inner Mongolia to determine the prevalence and MLG distribution of G. duodenalis. The PCR results of SSU rRNA revealed that the overall prevalence of G. duodenalis was 29.5% (149/505) and that the overall prevalence of the diarrhea and nondiarrhea samples was 31.5% (46/146) and 28.5% (103/359), respectively; the difference was not significant (p > 0.05). SSU rRNA sequence analysis revealed that G. duodenalis assemblage E (91.1%, 133/146) was primarily detected and that assemblage A (8.9%, 13/146) was detected in 13 samples. The G. duodenalis-positive samples were PCR amplified and sequenced for gdh, tpi, and bg, from which 38, 47, and 70 amplified sequences were obtained, respectively. A combination of G. duodenalis assemblages A and E were detected in seven samples. Multilocus genotyping yielded 25 different assemblage E MLGs, which formed six subgroups. To the best of our knowledge, this is the first report regarding G. duodenalis infection in dairy cattle in Inner Mongolia, China. This study revealed that Inner Mongolian cattle pose a risk of giardiasis transmission to humans and that the distribution of local cattle G. duodenalis assemblage E MLGs is diverse. The findings of this study can bridge the knowledge gap in the molecular epidemiological investigation of giardiasis in Central Inner Mongolia.

Molecular detection and characterization of Cryptosporidium spp., Giardia duodenalis, and Enterocytozoon bieneusi infections in dromedary camels (Camelus dromedaries) in Egypt

Introduction

Few studies have investigated the occurrence of microeukaryotic gut parasites in dromedary camels in Egypt, and the majority of these investigations are based on microscopic analysis of fecal material.

Methods

Herein, we assessed the occurrence, molecular diversity, and zoonotic potential of protozoan (Cryptosporidium spp. and Giardia duodenalis) and microsporidian (Enterocytozoon bieneusi) pathogens in individual fecal samples (n = 102) of dromedary camels with (n = 26) and without (n = 76) diarrhea from Aswan Governorate, Upper Egypt. Other factors possibly associated with an increased risk of infection (geographical origin, sex, age, and physical condition) were also analyzed. The SSU rRNA or ITS genes were targeted by molecular (PCR and Sanger sequencing) techniques for pathogen detection and species identification.

Results and discussion

The most abundant species detected was G. duodenalis (3.9%, 4/102; 95% CI: 1.1-9.7), followed by Cryptosporidium spp. (2.9%, 3/102; 95% CI: 0.6-8.4). All samples tested negative for the presence of E. bieneusi. Sequence analysis data confirmed the presence of zoonotic C. parvum (66.7%, 2/3) and cattle-adapted C. bovis (33.3%, 1/3). These Cryptosporidium isolates, as well as the four Giardia-positive isolates, were unable to be amplified at adequate genotyping markers (Cryptosporidium: gp60; Giardia: gdh, bg, and tpi). Camels younger than 2 years old were significantly more likely to harbor Cryptosporidium infections. This connection was not statistically significant, although two of the three cryptosporidiosis cases were detected in camels with diarrhea. The spread of G. duodenalis infections was unaffected by any risk variables studied. This is the first report of C. parvum and C. bovis in Egyptian camels. The finding of zoonotic C. parvum has public health implications since camels may function as sources of oocyst pollution in the environment and potentially infect livestock and humans. Although preliminary, this study provides useful baseline data on the epidemiology of diarrhea-causing microeukaryotic parasites in Egypt. Further research is required to confirm and expand our findings in other animal populations and geographical regions of the country.

Prevalence and pathology of Cephalopina titillator infestation in Camelus bactrianus from Xinjiang, China

BACKGROUND

In camels, nasopharyngeal myiasis is caused by the larvae of Cephalopina titillator, which parasitize the tissues of nasal and paranasal sinuses, pharynx, and larynx. C. titillator infestation adversely affects the health of camels and decreases milk and meat production and even death. However, the C. titillator infestation in Bactrian camels has not been widely studied.

METHODS

The present study was conducted to determine the prevalence and risk factors of C. titillator in Bactrian camels of northwestern Xinjiang. Suspected larvae recovered from infested camels were evaluated for C. titillator by microscopy and polymerase chain reaction. Nucleotide sequences of the partial mitochondrial cytochrome c oxidase subunit I (COX1) and cytochrome b (CYTB) genes from the C. titillator of camels were aligned from the NCBI database. Furthermore, the gross and histopathological alterations associated with C. titillator infestation were evaluated via pathological examination.

RESULTS

Of 1263 camels examined 685 (54.2%) camels were infested with suspected C. titillator larvae. Different larval stages were topically detected in the nasal passages and pharynx of the camel heads. Microscopy analysis of the pharyngeal mucosa tissue revealed necrotic tissue debris and some inflammatory cells. Molecular detection of the larval COX1 and CYTB genes indicated that pathogen collected in Bactrian camels was C. titillator. The epidemiological study demonstrated that the prevalence rate of C.titillator infestation was significantly higher in camels of Bestierek Town Pasture (67.2%) and Karamagai Town Pasture (63.6%) compared to Kitagel Town Pasture (38.7%) and Qibal Town Pasture (35.8%) (P < 0.05). No significant difference was observed between the prevalence rates in male (52.6%) and female (54.6%) camels (P > 0.05). The prevalence was higher in warm (64.2%) than that in cold (48.4%) seasons (P < 0.001). The prevalence in camels with non-nomadic method (67.2%) was significantly higher than in animals with nomadic method (47.5%) (P < 0.001). The prevalence of C.titillator infestation was significantly higher in animals of aged 5-10 (60.1%) and aged > 10 (61.1%) years old compared to those of aged < 5 (31.7%) years old camels (P < 0.001).

CONCLUSION

Our results confirm that there is a high prevalence of C. titillator in Bactrian camels from Xinjiang, closely related to age, season, pasture environment, and husbandry methods. Developing prevention, diagnosis, and control programs to prevent transmission is necessary.

Development and Preliminary Evaluation of a Nanoparticle-Assisted PCR Assay for the Detection of Cryptosporidium parvum in Calves

C. parvum is an important diarrheal pathogen in humans and animals, especially in young hosts. To accurately and rapidly detect C. parvum infection in calves, we established a nano-PCR assay targeting the cgd3_330 gene for the specific detection of C. parvum. This nano-PCR assay was ten times more sensitive than that of the normal PCR assay by applying the same primers and did not cross-react with C. andersoni, C. bovis, C. ryanae, Balantidium coli, Enterocytozoon bieneusi, Giardia lamblia, and Blastocystis sp. To further test the nano-PCR in clinical settings, a total of 20 faecal samples from calves were examined by using the nano-PCR, the normal PCR, and the nested PCR assays. The positive rates were 30% (6/20), 30% (6/20), and 25% (5/20) for the nano-PCR, the normal PCR, and the nested PCR assays, respectively, indicating that the nano-PCR and the normal PCR assays had the same positive rate (30%). Taken together, the present study could provide a candidate method for the specific detection of C. parvum infection in calves in clinical settings.

Molecular characterizations of Giardia duodenalis based on multilocus genotyping in sheep, goats, and beef cattle in Southwest Inner Mongolia, China

Giardia duodenalis is an important zoonotic parasite that causes economic losses to animal husbandry and threatens public health. In the present study, a total of 1466 fresh fecal samples were collected from sheep (n = 797), goats (n = 561) and beef cattle (n = 108) in Southwest Inner Mongolia, China. Giardia duodenalis was initially screened via nested polymerase chain reaction (PCR) targeting the β-giardin (bg) gene, and bg-positive samples were subjected to PCR amplification targeting the glutamate dehydrogenase (gdh) and triose phosphate isomerase (tpi) genes. A total of 4.0% of samples (58/1466) were positive for G. duodenalis, with a prevalence of 3.4% in sheep, 3.7% in goats and 5.2% in beef cattle. Three G. duodenalis assemblages (A, B, and E) were identified, with E as the prevalent assemblage. Four and one novel assemblage E sequences were obtained for the gdh and tpi loci, respectively and four assemblage E multilocus genotypes (MLG) were obtained. This study demonstrates high genetic variations in G. duodenalis assemblage E, and provides baseline data for preventing and controlling G. duodenalis infection in livestock in Inner Mongolia.

Giardia duodenalis in patients with diarrhea and various animals in northeastern China: prevalence and multilocus genetic characterization

Background

Giardia duodenalis is a common parasitic diarrheal agent in humans, especially in developing countries. The aim of this study was to investigate the prevalence and multilocus genetic characterization of G. duodenalis in patients with diarrhea and animals in northeastern China, and to assess the epidemiological role of animals in the transmission of human giardiasis.

Methods

A total of 1739 fecal specimens from 413 diarrheal patients and 1326 animals comprising 16 mammal species were collected in Heilongjiang Province of China and screened for G. duodenalis by PCR and sequencing of the SSU rRNA gene. All G. duodenalis-positive specimens were subtyped by PCR and sequencing of the bg, tpi, and gdh genes. To detect additional mixed infections of different assemblages, assemblage A/B/E-specific PCRs were performed to amplify the tpi gene.

Results

Sequence analysis of the SSU rRNA gene determined the prevalence of G. duodenalis (5.81%, 24/413) in diarrheal patients, with a peak in minors aged 5–17 years, and identified assemblages A and B. MLG-AII and MLG-B1 were obtained based on concatenated nucleotide sequences of the bg, tpi, and gdh genes, with MLG-AII being identical to a cat-derived isolate reported previously. By sequence analysis of the SSU rRNA gene, G. duodenalis was detected in 214 (16.14%) animals belonging to 11 mammal species, with the prevalence ranging from 1.69 to 53.85%, and assemblages A to G were identified. Sequence analysis of the bg, tpi, and gdh genes from 46 specimens produced 31 MLGs, including MLG-AI (n = 1), MLG-B2–B8 (n = 18), and MLG-E1–E23 (n = 27).

Conclusions

The finding of G. duodenalis in diarrheal patients enhances consciousness of detecting G. duodenalis in clinical practice and emphasizes the importance of health education in local inhabitants, especially in the age group of 5–17 years. The identification of seven assemblages (A to G) and 33 MLGs reveals genetic heterogeneity of G. duodenalis in the investigated areas. Due to insufficient homology data on the zoonotic transmission of G. duodenalis, the precise epidemiological role that animals play in the transmission of human giardiasis needs to be assessed by more large-scale molecular epidemiological investigations of local humans and animals.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13071-022-05269-9.