Molecular Detection of Giardia intestinalis from Stray Dogs in Animal Shelters of Gyeongsangbuk-do (Province) and Daejeon, Korea

Prevalence and genotype analysis of Cryptosporidium and Giardia duodenalis from shelter dogs in South Korea

Cryptosporidium and Giardia duodenalis are common gastrointestinal protozoan parasites that cause diarrhea in humans and animals. Although dogs in animal shelters in South Korea can be reintroduced into human society as companions, no continuous investigations have been conducted on the prevalence and genetic characteristics of the protozoan parasites. In the present study, 345 fecal samples from dogs were obtained from animal shelters in six provinces between January and December 2022. The prevalence of Cryptosporidium and G. duodenalis were molecularly identified at the 18S rRNA gene. Cryptosporidium canis isolates were subtyped at the gp60 locus, and G. duodenalis assemblages were identified at the tpi, bg and gdh loci. Overall, 6.67% of the fecal samples tested positive for Cryptosporidium spp. and two species were identified: C. canis (5.51%) and Cryptosporidium parvum (1.16%). Significant regional differences in prevalence were identified for C. canis. Subtyping analysis of C. canis isolates revealed a predominance of the subtype families XXa and XXe over XXb, and XXc. G. duodenalis was detected in 17.68% of the samples, and significant regional differences were identified; its prevalence was also significantly highest in diarrhoeic animals. Molecular characterization of G. duodenalis reveal that most isolates belonged to the canine-specific assemblages C and D. The present results can contribute to further insights into the prevalence and genotypes of Cryptosporidium and G. duodenalis in shelter dogs in South Korea.

Frequency and genotyping of Giardia duodenalis in dogs of Urmia, northwest of Iran

Giardia duodenalis is a zoonotic protozoan infecting various vertebrates such as humans and domestic animals. The aim of this study was to determine the frequency and genotypes of G. duodenalis using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in dogs of Urmia, Iran. Overall, 246 stool specimens were collected from 100 pet, 49 stray, and 97 shelter dogs in the Urmia, Iran. Totally, seven samples (2.48%) were microscopically positive in terms of Giardia cyst. The PCR-RFLP analysis revealed that three (1.21%) and two (0.83%) samples have the C and D genotypes, respectively. In addition, two samples (0.83%) were belonged to the AI sub-group. A significant association was determined between the frequency of Giardia infection and life style, age, and stool form of dogs. The findings of the study showed the high frequency of Giardia infection in stray dogs and the dogs under one-year-old. Furthermore, the C and D genotypes of G. duodenalis were predominant in dogs of Urmia, Iran.

Prevalence, diversity and public health implications of Helicobacter species in pet and stray dogs

Background

It is probable that humans can acquire H. pylori and non—H. pylori Helicobacter infections via domestic animals. The prevalence and risk factors of infections of Helicobacter species in canines of Taipei city were therefore analysed in this study.

Materials and methods

A total of 95 canine faecal samples were collected from different animal shelters and hospitals in Taipei city. Total DNA was extracted for semi-nested PCR detection of Helicobacter species. The PCR products were sequenced for further comparative database and phylogenetic analyses.

Results

The overall prevalence of Helicobacter species in canines of Taipei city was 75.79% (72/95). Two gastric, seven enterohepatic and two unclassified Helicobacter species were identified, all of which have been implicated in the aetiology of human diseases. The predominant species detected included H. canis (27.78%), H. pylori (26.39%), H. canicola (18.06%), and H. bilis (13.89%) in decreasing order, while H. canadensis and H. typhlonius were identified for the first time in canines. The genotypes in H. pylori and H. canicola clusters grouped together, with their respective reference strains, showed a close evolutionary distance in the phylogenetic tree, indicating a common ancestry may have existed in these clusters respectively. The residential region of canines, dog living status (pet or stray) and breed (purebred or mixed-breed) are the risk factors associated with Helicobacter infections in the canines examined.

Conclusion

The high prevalence of Helicobacter infections in canines highlights a potential public health risk of zoonotic transmission among dogs, humans and other animals, and therefore, the need for proper methods in controlling the transmission routes. In addition, the 16S rRNA gene amplification method was found to be useful for bacterial identification and phylogenetic analysis.

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The prevalence of Helicobacter infection in dogs of Taipei city was found to be 75.79%.

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Species detected included H. canis, H. pylori, H. canicola, H. bilis and others, including 2 unclassified species.

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Almost all the species detected are identical with those reported to be found in humans in some other studies, suggesting possible cross-transmission between humans and canines.

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Residential region, living status (pet or stray) and breed type of canines are risk factors associated with Helicobacter infections in the canines.

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Phylogenetic analysis indicated an evolutionary pattern in H. pylori and H. canicola clusters, suggesting a common ancestry may have existed in these clusters respectively.

Zoonotic giardiasis: an update

Giardia duodenalis is a common intestinal parasite in various hosts, with the disease giardiasis being a zoonosis. The use of molecular typing tools has improved our understanding of the distribution and zoonotic potential of G. duodenalis genotypes in different animals. The present review summarizes recent data on the distribution of G. duodenalis genotypes in humans and animals in different areas. The dominance of G. duodenalis assemblages A and B in humans and common occurrence of host-adapted assemblages in most domesticated animals suggests that zoonotic giardiasis is probably less common than believed and could be attributed mainly to contact with or contamination from just a few species of animals such as nonhuman primates, equines, rabbits, guinea pigs, chinchillas, and beavers. Future studies should be directed to advanced genetic characterization of isolates from well-designed epidemiological investigations, especially comparative analyses of isolates from humans and animals living in the same household or community. This will likely lead to better understanding of zoonotic transmission of G. duodenalis in different environmental and socioeconomic settings.

Genotypes of Giardia duodenalis in Household Dogs and Cats from Poland

BACKGROUND

Giardia duodenalis is a widespread protozoan parasite affecting humans and many species of animals, including dogs and cats. Due to its zoonotic potential, it is important to know the frequency of this parasite in companion animals. The aim of this study was to determine current epidemiological status of G. duodenalis in household dogs and cats.

METHODS

In this study, 293 fecal samples from pet dogs and cats were collected from January 2017 to July 2019 and tested for G. duodenalis by PCR (using β-giardin gene). The animals were divided into groups depending on their age, breed and fecal consistency.

RESULTS

The examination allowed for detection of G. duodenalis in 6.0% of canine and 3.9% of feline fecal samples. The highest frequency was revealed in young (under one-year old) dogs. Sequencing confirmed the presence of assemblages C and D in dogs and A and F in cats.

CONCLUSION

The study showed current frequency of G. duodenalis in dogs and cats and also revealed the occurrence of host-specific assemblages as well as zoonotic assemblage A.

DNA-based detection of Leptospira wolffii, Giardia intestinalis and Toxoplasma gondii in environmental feces of wild animals in Korea

Leptospira, Giardia intestinalis and Toxoplasma gondii infections are reported in humans and animals worldwide, but molecular surveillance of these pathogens in Korean wildlife is still limited. Here, we examined the prevalence of these pathogens in environmental feces of Eurasian otters, leopard cats and raccoon dogs using nested PCR followed by DNA sequencing. G. intestinalis was detected in all of three animals, while T. gondii was detected only in leopard cats. Leptospira wolffii was detected in raccoon dog and Eurasian otter. Our results suggest that these animals can act as a reservoir of these zoonotic pathogens. Consistent monitoring of these pathogens in wildlife is needed to prevent from their infections in humans and livestock in Korea.

Molecular prevalence and genotyping of Giardia duodenalis in cattle in Central Anatolia Region of Turkey

The molecular prevalence and genotypes of Giardia duodenalis in cattle were investigated. A total of 450 fecal samples were collected from cattle in three provinces of Central Anatolia from August 2017 to July 2019. Genomic DNA was extracted from the fecal samples and used in molecular analysis carried out by nested PCR analyses of the β-giardin (bg) gene of G. duodenalis. Positive samples were further analyzed by nested PCR at two gene loci (triosephosphate isomerase (tpi) and glutamate dehydrogenase (gdh)) for genotyping of G. duodenalis isolates. PCR analyses of the bg gene indicated that the overall prevalence of G. duodenalis was 30.2%. However, lower rates were determined with PCR analyses for gdh and tpi loci. The sequence analyses of the bg, gdh, and tpi genes revealed the presence of zoonotic assemblage A and livestock-specific assemblage E. Combined-sequence analyses revealed that assemblage E was the most common in the study area. Our study provides the first data on the wide prevalence of livestock-specific assemblages E in cattle in Turkey. The prevalence of assemblage A in cattle also reveals the importance of cattle for zoonotic transmission of giardiasis in Turkey.

Multilocus genotyping of Giardia duodenalis from pigs in Korea

Giardia duodenalis (syn. G. intestinalis, G. lamblia) is an important zoonotic parasite infecting livestock (including pigs) through ingesting cysts in contaminated food or water. This parasite has been classified into eight different genetic assemblages, A to H. Here, we examined the individual-level prevalence of G. duodenalis in domestic pig farms and confirmed host specificity by genotype comparisons. Samples were collected from southern and central Korea, between May 2017 and January 2019. DNA directly extracted from 745 pig fecal specimens were tested by PCR for G. duodenalis small subunit ribosomal RNA (ssu rRNA), glutamate dehydrogenase (gdh), and β-giardin gene sequences. Based on ssu rRNA PCR, 110 (14.8%) were positive for G. duodenalis. Infection risk was the highest in the fattener group (31/139, 22.3%) and during the autumn season (52/245, 21.2%: p < .001). No statistically significant differences in risk for infection were observed between fecal types (normal versus diarrheal). Fifty ssu rRNA samples, three gdh samples, and five β-giardin samples were successfully sequenced and genotyped. Ssu rRNA assemblage sequence analysis identified E (40.0%, 20/50), D (34.0%, 17/50), C (24.0%, 12/50), and A (2.0%, 1/50). The gdh locus identified three samples as assemblage E, and the β-giardin locus identified four samples as assemblage E and one as assemblage C. Assemblage A sequences obtained (ssu rRNA; MK430919) had 100% identity with Giardia sequences isolated from a Korean individual (AJ293301), indicating the potential of zoonotic transmission. Continuous management and monitoring for prevention of transmission and protection of animal and human health are essential.

Multilocus genotyping and risk factor analysis of Giardia duodenalis in dogs in Korea

Giardia duodenalis (syn. G. intestinalis, G. lamblia), a protozoan parasite that infects most mammals (including humans), has recently been classified into eight different groups/assemblages (A to H) based on host range and genetic characteristics. Assemblages A and B have been reported in humans and in many other animals, including dogs. This study analyzed Giardia infections, implementing multilocus genotyping, including the 18S rRNA, gdh, and β-giardin genes, in sheltered, companion, and special-purpose dogs throughout Korea. Of 640 dog stool samples, 99 (15.5%) were G. duodenalis-positive; this prevalence was similar to that previously reported in Korean calves. In addition, the prevalence was significantly higher in the southern region, and lower in non-sheltered dogs, older dogs, and in the autumn season. Phylogenetic analysis revealed that all G. duodenalis-positive samples belonged to assemblages C and D. Although no G. duodenalis assemblages A and B (mainly found in humans) were identified in this study, assemblage C was detected in the main types of dogs in contact with humans. Assemblage C, thought to be dog-specific, was recently identified in humans. As Giardia (including zoonotic assemblages) is distributed throughout Korea, dog living environments and the potential for dog-human transmission should be monitored.

Molecular epidemiology of giardiasis from a veterinary perspective

A total of eight Giardia species are accepted. These include: Giardia duodenalis (syn. Giardia intestinalis and Giardia lamblia), which infects humans and animals, Giardia agilis, Giardia ardeae, Giardia psittaci, Giardia muris, Giardia microti, Giardia peramelis and G. cricetidarum, which infect non-human hosts including amphibians, birds, rodents and marsupials. Giardia duodenalis is a species complex consisting of eight assemblages (A-H), with assemblages A and B the dominant assemblages in humans. Molecular studies to date on the zoonotic potential of Giardia in animals are problematic and are hampered by lack of concordance between loci. Livestock (cattle, sheep, goats and pigs) are predominantly infected with G. duodenalis assemblage E, which has recently been shown to be zoonotic, followed by assemblage A. In cats and dogs, assemblages A, B, C, D and F are commonly reported but relatively few studies have conducted molecular typing of humans and their pets and the results are contradictory with some studies support zoonotic transmission but the majority of studies suggesting separate transmission cycles. Giardia also infects a broad range of wildlife hosts and although much less well studied, host-adapted species as well as G. duodenalis assemblages (A-H) have been identified. Fish and other aquatic wildlife represent a source of infection for humans with Giardia via water contamination and/or consumption of undercooked fish and interestingly, assemblage B and A predominated in the two molecular studies conducted to date. Our current knowledge of the transmission dynamics of Giardia is still poor and the development of more discriminatory typing tools such as whole genome sequencing (WGS) of Giardia isolates is therefore essential.

Prevalence and risk factors of Giardia duodenalis in domestic rabbbits (Oryctolagus cuniculus) in Jilin and Liaoning province, northeastern China

BACKGROUND

Giardia duodenalis is one of the most important intestinal parasites that can infect virtually all animals, including rabbits and humans. However, there is little information regarding the prevalence and genotypes of G. duodenalis in domestic rabbits in China.

METHODS

A total of 426 rabbit fecal samples (136 from Shenyang City, 174 from Changchun City, and 116 from Jilin City) were examined by Lugol's iodine staining with microscopy analysis, and the positive samples were genotyped at the triosephosphate isomerase (tpi) and the beta giardin (bg) gene loci using nested PCR.

RESULTS

Forty-two (9.86%) out of 426 rabbit fecal samples were G. duodenalis-positive under microscopy analysis, and the highest G. duodenalis infection rate was 23.08% on farm 6. The prevalence of G. duodenalis in rabbits from different cities ranged from 1.47% to 14.37%. Among different age groups, G. duodenalis prevalence in rabbits ranged from 5.41% to 12.58%. The prevalence of G. duodenalis in outdoor rabbits and indoor rabbits was 14.29% and 6.77%, respectively. In the present study, region and farming mode were highly correlated with G. duodenalis infection in rabbits. All 42 G. duodenalis isolates were successfully amplified and sequenced at the tpi and bg loci, and only G. duodenalis assemblage B were identified.

CONCLUSION

This study not only further confirmed the dominance of G. duodenalis assemblage B in rabbits, but also further improved the foundation data concerning the distribution of G. duodenalis assemblages in China.

Practical Guidance for Clinical Microbiology Laboratories: Laboratory Diagnosis of Parasites from the Gastrointestinal Tract

This Practical Guidance for Clinical Microbiology document on the laboratory diagnosis of parasites from the gastrointestinal tract provides practical information for the recovery and identification of relevant human parasites. The document is based on a comprehensive literature review and expert consensus on relevant diagnostic methods. However, it does not include didactic information on human parasite life cycles, organism morphology, clinical disease, pathogenesis, treatment, or epidemiology and prevention. As greater emphasis is placed on neglected tropical diseases, it becomes highly probable that patients with gastrointestinal parasitic infections will become more widely recognized in areas where parasites are endemic and not endemic. Generally, these methods are nonautomated and require extensive bench experience for accurate performance and interpretation.

Detection of small number of Giardia in biological materials prepared from stray dogs

Giardia lamblia is an intestinal protozoa with intermittent and low shedding especially in dogs, and the detection of Giardia is accompanied with problems such as sampling and diagnostic method. The objective of this study was to detection of Giardia in biological materials with low number of parasite using parasitological and molecular methods, and also to determine whether the examined stray dogs harbor known zoonotic genotype of Giardia. For this aim 85 fecal and duodenal samples were studied from which 1 was positive by Trichrome staining of stool, 4 were positive by staining of duodenal samples. The nested PCR analysis with primers derived from 18 SrRNA showed that the specific PCR product could be amplified in 4 stool and 4 duodenal samples. All positive samples in staining analysis were also positive in nested PCR. No amplification could be observed by nested PCR with primers derived from β giardin gene due to the single copy of gene. Interestingly, the extracted DNA from old fixed stained Giardia positive smears could be also amplified with primers derived from 18SrRNA gene. The sequence analysis of nested PCR products showed that they belong to the genotype D. In conclusion, it is to denote that the Trichrome or Giemsa methods were not suitable for the detection of small number of this parasite in stool and the nested PCR with primers derived from 18S rRNA gene can replace the traditional methods successfully. For detection of Giardia in stool, primers derived from β giardin will not be recommended.

The presence of Giardia intestinalis in donkeys, Equus asinus, in China

Background

Giardia intestinalis is one of the most important zoonotic enteric parasites. As no information regarding prevalence and genotype of G. intestinalis in donkeys (Equus asinus) in China is available, 181 faecal samples from 48 donkeys from Jilin Province, from 104 from Shandong Province and from 29 from Liaoning Province were examined between May and December 2015.

Findings

Twenty-eight (15.47%) out of 181 donkey samples were tested G. intestinalis-positive by nested amplification of the triosephosphate isomerase (tpi) gene. The prevalence in different regional groups varied from 10.42 to 18.27%. The prevalence in adult and young donkeys was 14.29 and 22.92%, respectively. Otherwise, the prevalence was 11.69% in summer and 18.27% in winter. However, no statistically significant differences were found in relation to region or age group. Sequence analysis of the tpi, glutamate dehydrogenase (gdh) and beta giardin (bg) loci identified 4, 1 and 3 subtypes of assemblage B, respectively. Moreover, four novel multilocus genotypes (MLGs novel-1 to novel-4) were identified in assemblage B.

Conclusions

This first report of G. intestinalis in donkeys in China indicates that further studies of nation-wide molecular epidemiology and geographical distribution of Giardia in donkeys are warranted. Effective strategies should be implemented to control G. intestinalis infection in donkeys, other animals and humans.

Electronic supplementary material

The online version of this article (doi:10.1186/s13071-016-1936-0) contains supplementary material, which is available to authorized users.

Occurrence and multilocus genotyping of Giardia intestinalis assemblage C and D in farmed raccoon dogs, Nyctereutes procyonoides, in China

Background

Giardia intestinalis, the only causative agent of human giardiasis, can infect a wide range of animals. As no information concerning the prevalence and genotyping of G. intestinalis in raccoon dogs in China is available, examination of 305 faecal samples from raccoon dogs in Jilin Province (n = 110), Heilongjiang Province (n = 40), Liaoning Province (n = 72), Hebei Province (n = 54) and Shandong Province (n = 29) was conducted to estimate the prevalence of G. intestinalis in raccoon dogs in northern China and identify their genotypes using a genetic approach.

Findings

Of 305 faecal samples from farmed raccoon dogs, 22 (7.21 %) were detected G. intestinalis-positive by nested PCR amplification of the triosephosphate isomerase (tpi) gene. The prevalence of G. intestinalis was strongly related to the region and season of sampling. All 22 samples were analysed at the tpi, the glutamate dehydrogenase (gdh) and the beta giardin (bg) gene loci, showing 13, 3, 2 subtypes, respectively. The results also demonstrated that two raccoon dogs harboured mixed infections of assemblage C and assemblage D (or mixed C/D), whereas only assemblage C was detected in the remaining 20 samples. Moreover, five new multilocus genotypes, named as MLGs C1-C5, were observed in the assemblage C in the present study.

Conclusions

This is the first report of G. intestinalis infection in raccoon dogs in China. DNA sequence analysis of the tpi, gdh and bg gene indicated that 13, 3, 2 subtypes were found at these loci, respectively. Furthermore, this is also the first report of five new multilocus genotypes (MLGs C1-C5) in farmed raccoon dogs, which provides baseline data for further studies of the distribution of G. duodenalis in different hosts.

Molecular typing of canine Giardia duodenalis isolates from Minas Gerais, Brazil

Giardia duodenalis (syn. Giardia intestinalis and Giardia lamblia) is a widespread intestinal parasite in mammals, including humans and pets worldwide. It should be considered a species complex and comprises eight assemblage (A-H). This works aimed to determine the genotypic variability among G. duodenalis isolates from dogs from Minas Gerais state, Brazil. Fecal samples of 97 dogs, from 1-to-10 months old from 15 commercial kennels, were collected and analyzed by the zinc sulfate centrifugal flotation technique, to determine their positivity for G. duodenalis cysts. Cysts pellets were stored and submitted to PCR and nested-PCR reactions with gdh and tpi primers, and then sequencing. Among positive samples (n = 19), fragment amplifications of gdh and tpi genes was observed in 16 (84,2%) and 14 (73,6%), respectively. In total, 30 sequences were obtained. Sequencing analysis showed that for gdh, all isolates were identified as host-specific genotype D, and for tpi, besides host-specific genotype C, were also observed zoonotic genotypes A and B. This study provides, for the first time, current information about genetic characterization of G. duodenalis isolates found in dogs in Minas Gerais state.