Molecular identification of Giardia and Cryptosporidium from dogs and cats

Occurrence rate and species and subtypes of Cryptosporidium spp. in pet dogs in Yunnan Province, China

BACKGROUND

Cryptosporidium spp. is a ubiquitous, globally distributed intestinal protozoan infecting humans and at least 260 animal hosts. Due to close human contact with pet dogs and identification of zoonotic Cryptosporidium species and subtypes in these animals, dog health is not only a veterinarian issue but also a public health issue. This study aimed to understand occurrence and genetic characterization at both genotype and subtype levels in pet dogs in Yunnan Province, China.

RESULTS

A total of 589 fresh fecal specimens were collected from adult pet dogs in the rural areas of eight cities/autonomous prefectures of Yunnan Province, China. 16 fecal specimens were positive for Cryptosporidium spp. by polymerase chain reaction (PCR) amplification and sequence analysis of the small subunit ribosomal RNA (SSU rRNA) gene, with an average occurrence rate of 2.7% (16/589) being observed. Three zoonotic Cryptosporidium species were identified: C. parvum (n = 7), C. suis (n = 5) and C. canis (n = 4). At the 60-kDa glycoprotein (gp60) locus, only three C. parvum and two C. canis specimens were successfully amplified and sequenced, with subtype IIaA17G2R1 (n = 3) and subtypes XXa4 (n = 1) and XXa5 (n = 1) being identified, respectively.

CONCLUSIONS

The present finding of three zoonotic Cryptosporidium species in dogs implied that dogs infected with Cryptosporidium spp. may pose a threat to human health. C. suis was identified in dogs in this study for the first time, expanding the host range of this species. Identification of C. parvum subtype IIaA17G2R1 and C. canis subtypes XXa4 and XXa5 will be helpful to explore the source attribution of infection/contamination and assess the transmission dynamics of C. parvum and C. canis in the investigated areas in the future.

Molecular characteristics and zoonotic potential of enteric protists in domestic dogs and cats in Egypt

Introduction

Domestic dogs and cats can be a source of human infection by a wide diversity of zoonotic pathogens including parasites. Genotyping and subtyping tools are useful in assessing the true public health relevance of canine and feline infections by these pathogens. This study investigated the occurrence, genetic diversity, and zoonotic potential of common diarrhea-causing enteric protist parasites in household dogs and cats in Egypt, a country where this information is particularly scarce.

Methods

In this prospective, cross-sectional study a total of 352 individual fecal samples were collected from dogs (n = 218) and cats (n = 134) in three Egyptian governorates (Dakahlia, Gharbeya, and Giza) during July-December 2021. Detection and identification of Cryptosporidium spp., Giardia duodenalis, Enterocytozoon bieneusi, and Blastocystis sp. were carried out by PCR and Sanger sequencing. Basic epidemiological variables (geographical origin, sex, age, and breed) were examined for association with occurrence of infection by enteric protists.

Results and discussion

The overall prevalence rates of Cryptosporidium spp. and G. duodenalis were 1.8% (95% CI: 0.5-4.6) and 38.5% (95% CI: 32.0-45.3), respectively, in dogs, and 6.0% (95% CI: 2.6-11.4) and 32.1% (95% CI: 24.3-40.7), respectively, in cats. All canine and feline fecal samples analyzed tested negative for E. bieneusi and Blastocystis sp. Dogs from Giza governorate and cats from Dakahlia governorate were at higher risk of infection by Cryptosporidium spp. (p = 0.0006) and G. duodenalis (p = 0.00001), respectively. Sequence analyses identified host-adapted Cryptosporidium canis (n = 4, one of them belonging to novel subtype XXe2) and G. duodenalis assemblages C (n = 1) and D (n = 3) in dogs. In cats the zoonotic C. parvum (n = 5) was more prevalent than host-adapted C. felis (n = 1). Household dogs had a limited (but not negligible) role as source of human giardiasis and cryptosporidiosis, but the unexpected high frequency of zoonotic C. parvum in domestic cats might be a public health concern. This is the first molecular-based description of Cryptosporidium spp. infections in cats in the African continent to date. Molecular epidemiological data provided here can assist health authorities and policy makers in designing and implementing effective campaigns to minimize the transmission of enteric protists in Egypt.

The Role of Some Free-Ranging Animals in the Transmission of Multi-Host Species of Cryptosporidium Spp

Background

We aimed to characterize Cryptosporidium spp. in rats, cats, pigeons, and crows.

Methods

Fifty-five animal origin Cryptosporidium spp. genome were identified, genotyped and confirmed by nested PCR and of RFLP-PCR analysis as well as sequenced based on 18s rRNA and gp60 genes in Tehran (2012-2019). Finally, the phylogenetic analysis was performed by MEGA software (version 7).

Results

By the molecular method, Cryptosporidium spp. were detected in 24 (15.2%), 15 (15%), 2 (2%) and 13 (13%) cases of wild rats, cat, pigeon, and crow, respectively. Among the identified species by the RFLP pattern, most isolates were identified as C. parvum (24/157) 17.8% in rats, (15/100) 15% in cats, (13/100) 13%in crew and (2/100) 2% in pigeons; and the rest of the cases were C. muris and C. felis. The results of sequencing did not prove the existence of C. parvum, C. felis, C. muris, and rat genotype. Subtyping of C. parvum was indicated that the dominant subtype family belongs to the IId family and the subtype A20G1 was the most common subtype detected in all hosts while A19G1 was detected in one isolate of cat and pigeon.

Conclusion

Free-ranging animals are infected by species/subtype of Cryptosporidium, which can infect humans. This shows by itself the hygienic importance of the free-ranging animals in urban ecosystems. In the transmission of human cryptosporidiosis, the multi-host Cryptosporidium species such as C. parvum, C. felis, and C. muris can be transferred potentially from these animals to humans.

Gastrointestinal parasites in young dogs and risk factors associated with infection

Young dogs are particularly susceptible to infections with endoparasites. The occurrence of endoparasites was investigated in young dogs from Central Germany between July 2020 and July 2022. In total, 386 fecal samples originating from 171 dogs were examined for the prevalence of endoparasites using a combined flotation- and sedimentation technique and conventional PCR. Overall, in 41.2% (159/386) of the examined samples, endoparasites were detected. The most frequently occurring endoparasites were Giardia duodenalis (29%), Cryptosporidium spp. (9.1%), Cystoisospora spp. (7.3%), and Toxocara canis (6%). Sequencing of G. duodenalis positive samples showed that most infections belonged to the host-specific assemblages C (38.4% (43/112)) and D (35.7% (40/112)). The zoonotic assemblage A was identified in 8% (9/112) of the samples. Moreover, mixed infections were observed as follows: C/D in 5 (4.5%), D/A in 4 (3.6%), and C/A in 3 (2.7%) samples. All assemblage A infections were assigned to the potentially zoonotic subassemblage AI. Co-infections of G. duodenalis and Cryptosporidium spp. were observed in 3.1% (12/386) of the samples. Analyzing several host factors for their potential association with endoparasitic infection, the origin of dogs, as well as the living environment were identified as the main risk factors for infection with endoparasites. Overall, this study shows a high infection rate with endoparasites, especially G. duodenalis, in young dogs from Germany. The results of this study contribute to further insight into the distribution and potential risk factors associated with endoparasitic infections, as well as the zoonotic potential these parasites may present.

Molecular identification of Cryptosporidium, Giardia, and Blastocystis from stray and household cats and cat owners in Tehran, Iran

Cryptosporidiosis, giardiasis, and blastocystosis are among the most important parasitic diseases common between humans and cats. In addition, there are concerns about the possible transmission of zoonotic parasites from infected cats to humans. Hence, we investigated the molecular epidemiology of Cryptosporidium spp., Giardia duodenalis, and Blastocystis sp. in stray and household cats and cat owners. Our study was performed on 132, 33, and 33 fecal samples of stray and household cats, as well as cat owners in Tehran, Iran. Cryptosporidium spp. was identified using a nested PCR targeting the small subunit ribosomal RNA gene (SSU rRNA) and sequencing the internal amplified fragments. Furthermore, to perform multilocus genotyping of G. duodenalis, the ß-giardin (bg), glutamate dehydrogenase (gdh), and triosephosphate isomerase (tpi) genes were amplified to assess the DNA of G. duodenalis in the fecal samples of cats and cat owners. In addition, Blastocystis was detected by targeting the SSU rRNA gene, and the subtypes of Blastocystis were determined via the sequencing of amplicons. Cryptosporidium felis and Cryptosporidium canis were detected in seven stray cats (5.3%) and one household cat (3%). The bg gene of G. duodenalis was amplified and successfully sequenced in two (1.5%) stray cats and revealed assemblages F and B of G. duodenalis. Sequencing and phylogenic analysis of SSU rRNA gene nucleotide sequences of Blastocystis detected ST5 and ST10 in stray cats (1.5%), ST1 in household cats (9.1%), and ST1, ST2, ST3, and ST7 in owners (30.3%). The low prevalence of Cryptosporidium, Giardia and Blastocystis in cats and the presence of species/assemblages/subtypes with limited zoonotic potential indicate that cats had a minor role in their owners' infection in the investigated population. However, the presence of zoonotic protozoa in cats suggests the necessity of special attention to high-risk individuals during close contact with cats. Therefore, it is recommended that veterinarians, physicians, and urban managers plan to prevent, control, or treat these parasites to help the urban community live healthily alongside cats.

Cryptosporidium infection in young dogs from Germany

Cryptosporidium is an enteric protozoan parasite which is able to cause severe gastrointestinal disease and is distributed all over the world. Since information about the prevalence of cryptosporidiosis in German dogs is rare, the aim of this study was to examine the occurrence of Cryptosporidium spp. in dogs and the potential zoonotic risk emanating from these infected animals. In total, 349 fecal samples of 171 dogs were collected during the dogs’ first year of life. The samples were examined for Cryptosporidium spp. using PCR, targeting the small subunit ribosomal RNA gene (SSU rRNA). Further analysis of Cryptosporidium parvum and Cryptosporidium canis positive samples was accomplished using the 60 kDa glycoproteine gene (GP60). Overall, 10.0% (35/349) of the specimens were tested positive for Cryptosporidium. Cryptosporidium canis was found in 94.3% (33/35) of these samples and the zoonotic type C. pavum in 5.7% (2/35). Both C. parvum infections were subtyped as IIaA15G2R1. Sixteen of the C. canis positive samples were successfully amplified at the GP60 gene locus. These isolates were identified to belong to the subtype families XXd, XXe, or XXb; however, 2 samples could not be assigned to any of the described subtype families. Considering the close contact between pets and their owners, dogs may act as a potential source of infection for human cryptosporidiosis. The results of this study, in context with other studies from different countries, provide important further insights into the distribution of Cryptosporidium species in dogs and their zoonotic potential.

Molecular characterization of Cryptosporidium spp. and Giardia duodenalis in pet dogs in Xinjiang, China

Cryptosporidium spp. and Giardia duodenalis are opportunistic zoonotic protozoa transmitted through several routes. In this study, a total of 604 fecal samples were collected from pet dogs in Xinjiang, China to detect the presence of Cryptosporidium spp. and G. duodenalis by PCR amplification of the small subunit (SSU) rRNA gene. The incidence rate of Cryptosporidium spp. or G. duodenalis was 5.3% (32/604). Among the collection sites, a higher number of Cryptosporidium spp. or G. duodenalis positive dogs were detected in Hotan (9.9%, 21/213) and Shihezi (9.8%, 4/41) were higher than those in Aksu (4.5%, 1/22), Urumqi (2.1%, 4/191), and Korla (1.5%, 2/137). Among the sources, dogs in pet shops (7.4%, 19/256) showed a significantly higher incidence rate than those in pet hospitals (3.0%, 4/134) and pet kennels (2.3%, 5/214). When the data were examined by age, dogs < 1 year of age (6.1%, 28/459) were more likely to be infected by Cryptosporidium spp. or G. duodenalis than older (≥ 1 year) dogs (2.8%, 4/145). No significant differences were observed when animals were grouped by sex (5.0%, 14/278 for males; 5.5%, 18/326 for females). Sequence analysis revealed that the Cryptosporidium spp. (n = 10) in dogs were identified as C. canis. The G. duodenalis detected belonged to assemblages A (n = 1), C (n = 14), and D (n = 7). Among the identified 22 G. duodenalis isolates, eight samples were subtyped according to β-giardin (bg) and the results were consistent with the identified assemblages. To our knowledge, this is the first report of Cryptosporidium spp. and G. duodenalis infections in domesticated canines in Xinjiang, China. The C. canis and G. duodenalis assemblage A identified in pet dogs in the present study were previously associated with infections in humans, indicating the potential for zoonotic transmission.

Development of HRM real-time PCR for assemblage characterization of Giardia lamblia

A total of 90 stool samples were collected from dogs, referred to a dog shelter and a veterinary clinic. In addition, 395 stool samples obtained from pet dog owners and shelter keepers, as well as individuals referred to a medical laboratory as controls, were collected in Shahryar district, Tehran, Iran. Stool samples were parasitologically examined and the positive G. lamblia isolates were tested with Nested-PCR/sequencing for the tpi, gdh, and bg genes, and HRM real-time PCR. Microscopical examination revealed 20 (22.2%) and 34 (8.6%) Giardia-positive samples from dogs and humans, respectively. Regarding HRM real-time PCR, the prevalence of assemblages A and B in humans was 55.8% and 14.7%, respectively. In addition, 14.7% of samples were mix assemblages. HRM real-time PCR detected most of microscopically-positive samples in comparison to PCR/sequencing in both humans and dogs. The high prevalence of assemblages A and B in dogs signified the importance of a same source for infection between dogs and humans.

Raw meat based diet (RMBD) for household pets as potential door opener to parasitic load of domestic and urban environment. Revival of understated zoonotic hazards? A review

RMBD (acronym of Raw Meat Based Diet) and BARF diets (acronym for Biologically Appropriate Raw Food or Bones and Raw Food) account dietary regimens based on raw ingredients (including raw meat), popular in pet feeding. Animal tissues and organs as well as other uncooked ingredients are more and more popularly used by pet owners to feed household pets. However, the increased risk of exposure to microbiological and parasitic agents poses the question as to whether such diets may be recommendable to be handled and offered to domestic cats and dogs co-living in domestic and urban environment. Above all, the threat of human and animal infections by parasites from raw meat fed to pets is not sufficiently explored and tracked, meanwhile deserving particular surveillance, instead. At this regard, raw meat feeding to pets may represent a route of exposure to the increased risk of environmental load. In fact, some parasites typically found in rural environment can be given the chance to complete their life-cycle, for the closeness between definitive and intermediate hosts. This is of particular concern, as potentially infected pets serving as definitive hosts can become a continuous source of environmental diffusion of parasites, both at domestic and urban level. The handling of raw meat requires adequate knowledge and awareness of the hygienic principles to prevent the onset of disorders related to both manipulation by pet owners and uncooked food consumption by the pet. This review aimed to shed a comprehensive overview of the hygienic aspects related to raw pet feeding, as to handling of raw meat in domestic environment, with special emphasis on parasitic agents and related zoonotic hazards.

Molecular Investigation of Zoonotic Intestinal Protozoa in Pet Dogs and Cats in Yunnan Province, Southwestern China

Giardia duodenalis, Enterocytozoon bieneusi and Cryptosporidium spp. are common enteric pathogens that reside in the intestines of humans and animals. These pathogens have a broad host range and worldwide distribution, but are mostly known for their ability to cause diarrhea. However, very limited information on prevalence and genotypes of G. duodenalis, E. bieneusi and Cryptosporidium spp. in pet dogs and cats are available in China. In the present study, a total of 433 fecal samples were collected from 262 pet dogs and 171 pet cats in Yunnan province, southwestern China, and the prevalence and the genotypes of G. duodenalis, E. bieneusi and Cryptosporidium spp. were investigated by nested PCR amplification and DNA sequencing. The prevalence of G. duodenalis, E. bieneusi and Cryptosporidium spp. was 13.7% (36/262), 8.0% (21/262), and 4.6% (12/262) in dogs, and 1.2% (2/171), 2.3% (4/171) and 0.6% (1/171) in cats, respectively. The different living conditions of dogs is a risk factor that is related with the prevalence of G. duodenalis and E. bieneusi (p < 0.05). However, there were no statistically significant difference in prevalence of three pathogens in cats. DNA sequencing and analyses showed that four E. bieneusi genotypes (PtEb IX, CD9, DgEb I and DgEb II), one Cryptosporidium spp. (C. canis) and two G. duodenalis assemblages (C and D) were identified in dogs; two E. bieneusi genotypes (Type IV and CtEb I), one Cryptosporidium spp. (C. felis) and one G. duodenalis assemblage (F) were identified in cats. Three novel E. bieneusi genotypes (DgEb I, DgEb II and CtEb I) were identified, and the human-pathogenic genotypes/species Type IV C. canis and C. felis were also observed in this study, indicating a potential zoonotic threat of pet dogs and cats. Our results revealed the prevalence and genetic diversity of G. duodenalis, E. bieneusi and Cryptosporidium spp. infection in pet dogs and cats in Yunnan province, southwestern China, and suggested the potential threat of pet dogs and cats to public health.

Molecular characterization of Cryptosporidium spp. in dogs and cats in the city of Rio de Janeiro, Brazil, reveals potentially zoonotic species and genotype

Intestinal cryptosporidiosis is a diarrheal disease caused by protists of genus Cryptosporidium that infect a wide variety of hosts, primarily vertebrates. Due to the close contact between humans and their companion animals, especially dogs and cats, there is concern about the potential for zoonotic transmission of this enteric protozoan parasite by infected animals. This study aimed to perform a microscopic and molecular diagnosis of Cryptosporidium spp. in fecal samples from domiciled dogs and cats. One hundred and nineteen fecal samples were processed using sugar centrifugal flotation followed by molecular detection of Cryptosporidium spp. DNA using nested PCR. Subtyping of isolates positive for C. parvum was performed by sequence analysis of the 60 kDa glycoprotein gene (GP60). Cryptosporidium oocysts were detected in 7.8% (5/64) and 5.4% (3/55) of the fecal samples from dogs and cats, respectively. Cryptosporidium canis (n = 3) and C. parvum (n = 2) were the main species found in dogs, whereas C. felis (n = 3) was prevalent in cats. Subtype IIaA17G2R2 (potentially zoonotic) was identified in samples positive for C. parvum. Despite the low prevalence of Cryptosporidium observed in the domiciled dogs and cats, the presence of potentially zoonotic C. parvum in dogs evidences a public health concern. Further research is needed to better understand the epidemiology, source, and potential impacts of Cryptosporidium infection in cats and dogs.

The global prevalence and risk factors of Cryptosporidium infection among cats during 1988-2021: A systematic review and meta-analysis

Cryptosporidiosis is an important zoonosis caused by Cryptosporidium. This disease causes a global public health problem. The cat is considered to be one of the potential hosts for transmitting Cryptosporidium to humans. In this study, a global meta-analysis for Cryptosporidium infection in cats was performed. The articles related to Cryptosporidium infection in cats were systematically searched in databases China National Knowledge Infrastructure (CNKI), Wanfang data, VIP Chinese Journal Database, PubMed, and ScienceDirect. Finally, 92 articles published from 1988 to 2021, which met the criteria of systematic review and meta-analysis, were collected. During the selected period, the overall prevalence of Cryptosporidium among cats was identified to be 6.0%. The prevalence of Cryptosporidium detected by microscopy, coproantigens, and molecular biology methods were 4.2%, 8.2%, and 5.0%, respectively. Among 9 species/genotypes (C. felis, C. parvum, C. muris, Cryptosporidium rat genotype IV, C. baileyi, C. ryanae, C. hominis, Cryptosporidium sp. rat genotype III and most closely related to Cryptosporidium sp. rat genotype III), the prevalence of C. parvum (4.2%) was significantly higher than that of other species/genotypes. Among five continents, the prevalence of Cryptosporidium in Africa (30.5%) was significantly higher than in other continents. We also analyzed the effects of different geographical factors (longitude, latitude, altitude, mean temperature, precipitation, and humidity) on Cryptosporidium infection among cats. The results showed that cryptosporidiosis was common in cats all over the world. This systematic review and meta-analysis has systematically introduced the global epidemiology of Cryptosporidium in cats and correlated risk factors. Health authorities, doctors, veterinarians and cat owners' awareness of the prevalence, risk factors and complications of Cryptosporidium are important for the development of effective prevention strategies for cryptosporidiosis.

Advances in molecular epidemiology of cryptosporidiosis in dogs and cats

The use of molecular tools has led to the identification of several zoonotic Cryptosporidium spp. in dogs and cats. Among them, Cryptosporidium canis and Cryptosporidium felis are dominant species causing canine and feline cryptosporidiosis, respectively. Some Cryptosporidium parvum infections have also been identified in both groups of animals. The identification of C. canis, C. felis and C. parvum in both pets and owners suggests the possible occurrence of zoonotic transmission of Cryptosporidium spp. between humans and pets. However, few cases of such concurrent infections have been reported. Thus, the cross-species transmission of Cryptosporidium spp. between dogs or cats and humans has long been a controversial issue. Recently developed subtyping tools for C. canis and C. felis should be very useful in identification of zoonotic transmission of both Cryptosporidium spp. Data generated using these tools have confirmed the occurrence of zoonotic transmission of these two Cryptosporidium spp. between owners and their pets, but have also shown the potential presence of host-adapted subtypes. Extensive usage of these subtyping tools in epidemiological studies of human cryptosporidiosis is needed for improved understanding of the importance of zoonotic transmission of Cryptosporidium spp. from pets.

Molecular characterization of Giardia spp. and Cryptosporidium spp. from dogs and coyotes in an urban landscape suggests infrequent occurrence of zoonotic genotypes

Giardia spp. and Cryptosporidium spp. are common gastrointestinal parasites with the potential for zoonotic transmission. This study aimed to (1) determine the genotypes occurring in dogs and coyotes occupying a similar urban area; (2) determine if these hosts were infected with potentially zoonotic genotypes; (3) provide baseline molecular data. In August and September 2012, 860 dog owners living in neighborhoods bordering six urban parks in Calgary, Alberta, Canada, provided faecal samples from their dogs. From March 2012 through July 2013, 193 coyote faeces were also collected from five of six of the same parks. Direct immunofluorescence microscopy (DFA) indicated that Giardia spp. and Cryptosporidium spp. infected a total of 64 (7.4%) and 21 (2.4%) dogs, as well as 15 (7.8%) and three (1.6%) coyotes, respectively. Semi-nested, polymerase chain reactions targeting the 16S small-subunit ribosomal ribonucleic acid (SSU rRNA) and 18S SSU rRNA genes of Giardia spp. and Cryptosporidium spp., respectively, were conducted on samples that screened positive by DFA, and products were sequenced and genotyped. Dogs were infected with Giardia intestinalis canid-associated assemblages C (n = 14), D (n = 13), and Cryptosporidium canis (n = 3). Similarly, G. intestinalis assemblages C (n = 1), D (n = 1) and C. canis (n = 1), were detected in coyotes, as well as G. intestinalis assemblage A (n = 1) and Cryptosporidium vole genotype (n = 1). Dogs and coyotes were predominantly infected with host-specific genotypes and few potentially zoonotic genotypes, suggesting that they may not represent a significant risk for zoonotic transmission of these parasites in urban areas where these hosts are sympatric.

Development of a gp60-subtyping method for Cryptosporidium felis

BACKGROUND

Feline cryptosporidiosis is an increasing problem, especially in catteries. In humans, close contact with cats could be a potential source of infection although the risk of contracting cryptosporidiosis caused by Cryptosporidium felis is considered to be relatively low. Sequencing of the 60-kDa glycoprotein gene is a commonly used tool for investigation of the genetic diversity and transmission dynamics of Cryptosporidium species. However, until now the sequence of gp60 from C. felis has not been available and genotyping has been limited to less discriminatory markers, such as 18S rRNA, COWP and HSP70.

METHODS

We have identified the gp60 orthologue within the genome sequence of C. felis, and used the sequence to design a nested PCR for subtyping purposes. A total of 128 clinical isolates of both feline and human origin, were used to evaluate the marker.

RESULTS

Sequence analysis revealed large variations between the different samples. The C. felis gp60 lack the characteristic serine-tract found in many other cryptosporidian orthologues, instead it has an insertion of variable length (361-742 nt). Also, two cases of suspected zoonotic transmission of C. felis between cats and humans were successfully confirmed.

CONCLUSIONS

We have identified the gp60 gene in C. felis and show how this highly variable marker can be used in epidemiological investigations.

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.

Leishmania infantum, Dirofilaria spp. and other endoparasite infections in kennel dogs in central Italy

Prevalence and risk factors of Leishmania infantum, Dirofilaria spp. and other potentially zoonotic or canine-specific endoparasite infections were assessed in 639 kennel dogs from central Italy. To this end, individual blood and fecal samples were examined using parasitological, immunological and molecular techniques. The presence of compatible clinical pictures, as well as age and gender were considered as putative risks factors. To evaluate risk factors, multivariable analysis with logistic regression and univariable analysis with a Chi square test and a Fischer's exact test were performed. Overall, 52.6% of dogs (95% CI 48.6-56.5) were found positive, while 39.6% of dogs (95% CI 35.8-43.5) were infected by potentially zoonotic species. Leishmania infantum and Dirofilaria repens showed prevalences of 2.5% (95% CI 1.5-4.1) and 2.8% (95% CI 1.7-4.5), respectively. The prevalence of cardiorespiratory parasites was 7.8% (95% CI 5.9-10.3) and included the species Angiostrongylus vasorum, Eucoleus aerophilus, Eucoleus boehmi and D. immitis; the latter showed a prevalence of 0.2% (95% CI 0.001-1). Intestinal parasites were significantly prevalent (38.8%, 95% CI 35-42.7) and they consisted mainly of species of major zoonotic concern, including ancylostomatids, Toxocara canis, Giardia duodenalis, Dipylidium caninum, Taeniidae, Strongyloides stercoralis and Cryptosporidium parvum. Endoparasites were significantly prevalent in clinically suspected dogs. Leishmania infantum and cardiorespiratory nematodes were prevalent in older dogs, while intestinal parasites were prevalent in younger dogs. Results show high dog and public health risks in kennels in central Italy, and suggest the need for more effective control measures.

Assessment of the diagnostic performance of four methods for the detection of Giardia duodenalis in fecal samples from human, canine and feline carriers

Enteric parasitic diseases including giardiasis are of public health concern. Different methods are available for the diagnosis of this parasitic infection in fecal samples such as the identification of protozoan cysts and trophozoites by light microscopy, detection of specific antigens by ELISA, and amplification of DNA fragments by PCR. The present study aimed at assessing the performance of four laboratory tests for the detection of Giardia duodenalis in fecal specimens from three different host species with a previous diagnosis of giardiasis; canine, feline and human patients provided new stool samples to be retested for Giardia before initiating treatment with antiprotozoal drugs. For this purpose, triplicate fecal specimens from 54 humans, 24 dogs and 18 cats living in the city of Niterói, RJ, southeast Brazil, were analysed by light microscopy, ELISA, immunochromatography, and nested PCR. The centrifugal-flotation method detected Giardia cysts in 89.6% (86/96) of the fecal samples. The protozoan parasite was detected via immunochromatography in 87.5% (84/96) of these samples. Giardia was detected by ELISA in 69.8% (67/96) of the stool specimens from carriers with a previous diagnosis of Giardia infection. Giardia was detected by PCR in only 39.6% (38/96) of the fecal specimens. Based on these findings, we suggest that, among the four assays that were used in this study, the zinc sulphate flotation technique (Faust et al., 1939) is the best diagnostic assay in terms of sensitivity and specificity to detect G. duodenalis on serially collected samples from dogs, cats and humans.

Identification of pig-specific Cryptosporidium species in mixed infections using Illumina sequencing technology

Nowadays molecular methods are widely used in epidemiological studies of Cryptosporidium infections in humans and animals. However to gain better understanding of parasite species or genotypes, especially when mixed infections are noticed, highly sensitive tools with adequate resolution power need to be employed. In this article, we report an application of the next generation sequencing method (NGS) for detection and characterisation of Cryptosporidium species concurrently present in pig faeces. A mixture of Cryptosporidium DNA obtained from two faecal samples was amplified at the 18 SSU rRNA gene locus and the resulting amplicons were subsequently used for MiSeq sequencing. Although initial molecular analyses indicated the possible presence of another Cryptosporidium species other than Cryptosporidium scrofarum and Cryptosporidium suis, deep sequencing only confirmed the presence of pig-specific Cryptosporidium.

Detection of Giardia duodenalis assemblage E infections at the Tibetan Plateau Area: Yaks are suitable hosts

The prevalence of Giardia duodenalis (G. duodenalis) assemblages in yaks is poorly known. The present study examined 297 fecal samples from weaned yak, 4-7 months of age, from 3 different farms, in Tibetan Plateau Area (TPA) of the Qinghai Province in Western China. The prevalence of infection was determined by light and immunofluorescence microscopy, and nested-PCR. PCR was performed for the small subunit ribosomal RNA (SSU) amplified 16 positive for G. duodenalis products. The prevalence of Giardia species was 5.0% (15/297) on light microscopic analysis, 6.1% (18/297) on immunofluorescence test (IFT) and 5.4% (16/297) on nested-PCR. The overall prevalence with the three methods was 5.5%. Ten of the 16 PCR products have been successfully sequenced. Sequence results and phylogenetic analysis of the 18S rRNA sequence data using MEGA5.0 and DNAstar7.0 identified all samples of interest as G. duodenalis assemblage E. This study revealed for the first time the presence of G. duodenalis in yaks from the Qinghai province in China and confirmed that yak is a suitable host for Giardia parasites. The results provide useful information about G. duodenalis prevalence and the epidemiological significance of yak a suitable host to harbor Giardia infections.

Diagnostic accuracy of two point-of-care kits for the diagnosis of Giardia species infection in dogs

OBJECTIVES

The objective of this study was to compare results obtained by ZnSO₄ Flotation and SNAP ^®Giardia to those generated by the new point‐of‐care tests Single and Triple Rapid.

METHODS

Prospective study evaluating 51 canine faecal samples submitted at a reference laboratory for the presence of Giardia spp. Kappa statistics, specificity, sensitivity, positive predictive value (PPV) and negative predictive value (NPV) were calculated by comparing the new tests to the combined results of ZnSO₄ and SNAP tests.

RESULTS

There was fair (Single Rapid, j=0·434) to good (Triple Rapid, j =0·797) agreement with the reference tests. At this study's prevalence (59 to 61%), specificities and PPV were high (1·00) with both Rapid tests, but sensitivities and NPV were lower for the Single than for the Triple (0·48 vs 0·83 and 0·55 vs 0·80) tests. At lower prevalence rates, both tests exhibited a high PPV (1·00), but the NPV were higher with the Triple (0·96 to 0·99) than the Single (0·88 to 0·96) Rapid test.

CLINICAL SIGNIFICANCE

Both tests exhibited excellent PPV values at all prevalence rates but an excellent NPV only at low prevalence. As the prevalence is likely to be low (<15%) in clinical settings, we propose that these tests may be helpful in the in‐house diagnosis of Giardia spp infection. However, they exhibit lower sensitivity than the combined sensitivity of ZnSO₄ and SNAP tests, particularly in high prevalence settings.

Development of T m -shift genotyping method for detection of cat-derived Giardia lamblia

To develop T _m -shift genotyping method for detection of cat-derived Giardia lamblia, two sets of primers with two GC-rich tails of unequal length attached to their 5'-end were designed according to two SNPs (BG434 and BG170) of β-giardin (bg) gene, and specific PCR products were identified by inspection of a melting curve on real-time PCR thermocycler. A series of experiments on the stability, sensitivity, and accuracy of T _m -shift method was tested, and clinical samples were also detected. The results showed that two sets of primers based on SNP could distinguish accurately between assemblages A and F. Coefficient of variation of T _m values of assemblage A and F was 0.14 and 0.07% in BG434 and 0.10 and 0.11% in BG170, respectively. The lowest detection concentration was 4.52 × 10^-5 and 4.88 × 10^-5 ng/μL samples of assemblage A and F standard plasmids. The T _m -shift genotyping results of ten DNA samples from the cat-derived G. lamblia were consistent with their known genotypes. The detection rate of clinical samples by T _m -shift was higher than that by microscopy, and their genotyping results were in complete accordance with sequencing results. It is concluded that the T _m -shift genotyping method is rapid, specific, and sensitive and may provide a new technological mean for molecular detection and epidemiological investigation of the cat-derived G. lamblia.

Efficacy of nitazoxanide to treat natural Giardia infections in dogs

Background

Giardia parasites cause gastrointestinal disease in humans, dogs, and many other animals worldwide. The treatment of dogs for giardiasis requires further investigation to ascertain levels of drug efficacy and the possibility of adverse side effects. Nitazoxanide (NTZ) has shown good clinical anti-Giardia activity in humans, yet it has not been evaluated for the treatment of giardiasis in dogs.

Methods

Thirty-five dogs, naturally infected with Giardia were divided into five groups (n = 7): dogs in group NTZ1, NTZ2, and NTZ3 were treated with a single oral dose of 37.5 mg/kg, 75 mg/kg, and 150 mg/kg, respectively, of NTZ on days 0 and 14. The fourth group was treated with a commercially available regimen that includes a combination of pyrantel, praziquantel, and febantel (FEB) administered orally for three consecutive days. Additionally, an untreated control group was established. Giardia cysts from the stool of each dog were quantified on days -3, 0, 5, 7, 9, 11, 14, 18, 25, and 28. Biochemical parameters were evaluated in all dogs, before the first treatment and after concluding the experiment.

Results

Shedding of Giardia cysts was reduced in all treated groups when compared to untreated controls (P < 0.01). However, NTZ2, NTZ3, and FEB had a lower risk during the study. Furthermore, NTZ was also effective against another protozoan, Cryptosporidium spp. at doses of 75 mg/kg and 150 mg/kg, in contrast to the combination of febantel + pyrantel + praziquantel. Biochemical parameters of treated animals, namely, aspartate transaminase and alanine transaminase enzymes, remained within physiological ranges.

Conclusions

Based on these results, the implementation of NTZ as a treatment for giardiasis in dogs is proposed. The administration of a single dose is an important advantage of NTZ because it reduces workload, particularly in animals placed in shelters and kennels, where handling of large numbers of animals is required, and personnel is frequently scarce.

Giardia and Cryptosporidium spp. dissemination during wastewater treatment and comparative detection via immunofluorescence assay (IFA), nested polymerase chain reaction (nested PCR) and loop mediated isothermal amplification (LAMP)

Environmental water samples from the Lower Rhine area in Germany were investigated via immunofluorescence assays (IFAs), nested polymerase chain reaction (nested PCR) and loop-mediated isothermal amplification (LAMP) to detect the presence of Giardia spp. (n=185) and Cryptosporidium spp. (n=227). The samples were concentrated through filtration or flocculation, and oocysts were purified via centrifugation through a sucrose density gradient. For all samples, IFA was performed first, followed by DNA extraction for the nested PCR and LAMP assays. Giardia cysts were detected in 105 samples (56.8%) by IFA, 62 samples (33.5%) by nested PCR and 79 samples (42.7%) by LAMP. Cryptosporidium spp. were detected in 69 samples (30.4%) by IFA, 95 samples (41.9%) by nested PCR and 99 samples (43.6%) by LAMP. According to these results, the three detection methods are complementary for monitoring Giardia and Cryptosporidium in environmental waters.

Emergent and re-emergent parasites in HIV-infected children: immunological and socio-environmental conditions that are involved in the transmission of Giardia spp. and Cryptosporidium spp

INTRODUCTION

Emergent and re-emergent waterborne protozoans have become a worldwide public health problem, especially among vulnerable groups.

METHODS

This cross-sectional study evaluated 17 HIV-infected children and their families.

RESULTS

A high (76.5%) percentage of parasite-infected children was observed, even among children with CD4+ T-cell counts of >200 cells/mm3. Giardia spp., Cryptosporidium spp. and Cyclospora spp. were observed in 41.2% of these children Low income, poor hygiene practices, and co-infection in domestic, peridomestic and scholastic environments were significant sources of these intestinal infections.

CONCLUSIONS

Early diagnosis, timely treatment, and socio-educational interventions may improve the health conditions of this vulnerable population.

PCR-RFLP method to detect zoonotic and host-specific Giardia duodenalis assemblages in dog fecal samples

Giardia duodenalis is a zoonotic protozoan that parasitizes the upper small intestine of human and many mammals including dogs. To develop a restriction fragment length polymorphism (RFLP) method for typing zoonotic (A, B) and host-specific (C, D) assemblages of G. duodenalis from dog, β-giardin gene was amplified with design primer pairs B3 and B4. The PCR products were digested with restriction enzyme Afa I and Msp I; then, PCR-RFLP method was compared with HRM genotyping and sequencing method for G. duodenalis from dog. The results showed that each of assemblages A-D had unique restriction pattern, which was consistent with the predictive results. Among 21 samples tested by PCR-RFLP, 1 human-derived and 8 dog-derived G. duodenalis were identified as assemblage A; 5 dog-derived G. duodenalis as assemblage C; 7 dog-derived G. duodenalis as assemblage D, which were coincided with the HRM genotyping and sequencing results. It is concluded that the PCR-RFLP is quick, easy, and accurate method for the sequence typing of G. duodenalis zoonotic and specific assemblages from dogs.

Something old, something new: Update of the 2009 and 2013 ABCD guidelines on prevention and management of feline infectious diseases

OVERVIEW

The ABCD has published 34 guidelines in two Special Issues of the Journal of Feline Medicine and Surgery (JFMS): the first in July 2009 (Volume 11, Issue 7, pages 527-620) and the second in July 2013 (Volume 15, Issue 7, pages 528-652). The present article contains updates and new information on 18 of these (17 disease guidelines and one special article 'Prevention of infectious diseases in cat shelters'). For detailed information, readers are referred to the guidelines published in the above-mentioned JFMS Special Issues.

Validation of a real-time PCR assay for the molecular identification of Mycobacterium tuberculosis

Mycobacterium tuberculosis is the major cause of tuberculosis in humans. This bacillus gained prominence with the occurrence of HIV, presenting itself as an important opportunistic infection associated with acquired immunodeficiency syndrome (AIDS). The current study aimed to develop a real-time PCR using Eva Green technology for molecular identification of M. tuberculosis isolates. The primers were designed to Rv1510 gene. Ninety nine samples of M. tuberculosis and sixty samples of M. bovis were tested and no sample of the bovine bacillus was detected by the qPCR. Statistical tests showed no difference between the qPCR and biochemical tests used to identify the Mycobacterium tuberculosis. The correlation between tests was perfect with Kappa index of 1.0 (p < 0.001, CI = 0.84 - 1.0). The diagnostic sensitivity and specificity were 100% (CI = 95.94% - 100%) and 100% (CI = 93.98% - 100%). This qPCR was developed with the goal of diagnosing the bacillus M. tuberculosis in samples of bacterial suspension. TB reference laboratories (health and agriculture sectors), public health programs and epidemiological studies probably may benefit from such method.

The epidemiology of infections with Giardia species and genotypes in well cared for dogs and cats in Germany

BACKGROUND

Giardia is now considered the most common enteric parasite in well cared for dogs and cats in developed countries. The ecology, epidemiology and clinical impact of infections with this parasite in such animals is still not fully understood due to variable results across different studies.

METHODS

Faecal samples were collected between 2009 and 2012 from privately owned cats and dogs in Germany presented to local veterinarians for a variety of reasons. Giardia positive samples were identified by microscopy and coproantigen methods. Total faecal DNA was extracted from Giardia positive samples and multilocus genotyping methods (18S rDNA, β-giardin, GDH) were applied. Relationships between host age, sex, and breed, season of presentation and the different species of Giardia detected were assessed.

RESULTS

A total of 60 cat and 130 dog samples were identified as Giardia positive. Potentially zoonotic Giardia was identified in both animal species. Cats had a similarly high rate of infection with the G. duodenalis and G. cati. Cats less than 1 year were more likely to have G. duodenalis than cats older than 1 year. Pure breed cats demonstrated a greater proportion of zoonotic species than mixed breed cats. In samples from dogs, G. canis (C and D genotypes) were identified most commonly. Male dogs were more likely to have G. canis (genotype D) than female dogs. The 18S rDNA PCR protocol was the most successful followed by the β-giardin and GDH (amplifying from 92%, 42% and 13% of samples respectively).

CONCLUSIONS

The potentially zoonotic species G. duodenalis and G. enterica were found in cat and dog samples, with G. duodenalis found in greater numbers; however, this may be due to the detection techniques utilised. Cats appeared to show a relationship between G. duodenalis and G. cati with age and breed, which may be explained by different housing habitats for pure and mixed breed cats. The different success rates for the three loci utilised highlights the usefulness of the 18S locus as a screening tool, as well as the importance of using multiple loci for genotyping to fully determine the level of multiple infection of Giardia present.

Zoonotic potential of Giardia

Giardia duodenalis (syn. Giardia lamblia and Giardia intestinalis) is a common intestinal parasite of humans and mammals worldwide. Assessing the zoonotic transmission of the infection requires molecular characterization as there is considerable genetic variation within G. duodenalis. To date eight major genetic groups (assemblages) have been identified, two of which (A and B) are found in both humans and animals, whereas the remaining six (C to H) are host-specific and do not infect humans. Sequence-based surveys of single loci have identified a number of genetic variants (genotypes) within assemblages A and B in animal species, some of which may have zoonotic potential. Multi-locus typing data, however, has shown that in most cases, animals do not share identical multi-locus types with humans. Furthermore, interpretation of genotyping data is complicated by the presence of multiple alleles that generate "double peaks" in sequencing files from PCR products, and by the potential exchange of genetic material among isolates, which may account for the non-concordance in the assignment of isolates to specific assemblages. Therefore, a better understanding of the genetics of this parasite is required to allow the design of more sensitive and variable subtyping tools, that in turn may help unravel the complex epidemiology of this infection.