First report on Giardia duodenalis assemblage F in Slovakian children living in poor environmental conditions

Molecular characterization of Cryptosporidium spp. and Giardia duodenalis in pet cats in Henan Province, central China

Cryptosporidium spp. and G. duodenalis often infect humans, cats, and other mammals, causing diarrhea and being responsible for numerous outbreaks of waterborne and foodborne infections worldwide. The rapid increase in the number of pet cats poses a substantial public health risk. However, there were few reports about the infection of Cryptosporidium spp. and G. duodenalis infections in pet cats in Henan Province, central China. Thus, to understand the prevalence and genetic distribution of Cryptosporidium spp. and G. duodenalis in pet cats, and to evaluate the zoonotic potential, possible transmission routes and public health implications of isolates, fecal samples (n = 898) were randomly collected from pet cats in 11 cities in Henan Province, central China. Nested PCR based on the SSU rRNA gene and bg gene was used to the prevalence of Cryptosporidium spp. and G. duodenalis, respectively. The prevalence was 0.8 % (7/898) and 2.0 % (18/898) for Cryptosporidium spp. and G. duodenalis respectively. Additionally, the Cryptosporidium spp. positive isolates were identified as C. parvum subtype IIdA19G1 by gp60 gene. In the present study, the IIdA19G1 subtype was discovered in pet cats for the first time in China, enriching the information on the host type and geographical distribution of Cryptosporidium spp. in China. For G. duodenalis, a total of 18 G. duodenalis positive samples were identified, belonging to four assemblages: a zoonotic assemblage A1 (4/898), three host-specific assemblages C (8/898), D (5/898), and F (1/898). Interestingly, we found that pet cats infected with Cryptosporidium spp. and G. duodenalis are more likely to experience emaciation symptoms compared to the negative group. More importantly, the prevalence of Cryptosporidium spp. and G. duodenalis detected in the present study were low, but the subtype IIdA19G1 of Cryptosporidium spp. and the assemblages A1, C, D, and F of G. duodenalis have the potential for zoonotic transmission. Thus, we should focus on preventing and controlling the risk of cross-species transmission that may occur in pet cats in Henan Province.

Awareness of parasitic zoonotic diseases among pet owners in Cairo, Egypt

Egyptians are becoming more interested in owning and raising pets; however, most of them lack essential awareness about the risk of zoonotic parasites that could be transmitted. The objective of the present investigation was to evaluate the degree of awareness Egyptian pet owners possess concerning zoonotic parasitic diseases, the risk of transmission, and preventative measures. A cross-sectional study was conducted using an e-survey. Among 246 pet owners, 64.2% (158) were females, and 67.9% (167) belonged to the 20-30 age group. The majority, 78.9% (194), were raising cats. Only 13.8% (34) visited the veterinarian regularly, with significantly higher results among dog owners (p < 0.05). Only 31.3% (77) participants were regularly deworming their pets, and 19.9% (49) were giving their pets prophylaxis against ectoparasites, with significantly higher results among those who visited the veterinarian regularly (p < 0.0001) and among dog owners (p < 0.05). Only 54.1% (133) had heard about the term "zoonoses" before, and about 8.9% (22) of participants showed a history of zoonotic parasitic diseases, with significantly higher results among those who allowed their animals to play with other animals of neighbors and friends (p < 0.05). The obtained results concluded that the surveyed group had a relatively good degree of knowledge regarding pets as a source of zoonotic illness; raising pet owners' awareness regarding the importance of routine medical examinations and minimizing the contact of pets with other stray animals is essential.

Prevalence and assemblage of Giardia duodenalis in a case-control study of children under 5 years from Jimma, Southwest Ethiopia

Giardia duodenalis is a common pathogenic intestinal protozoan parasite with high prevalence in developing countries, especially among children. The distribution of giardia assemblages among humans and their clinical relevance remains controversial. This study aimed to determine the prevalence and assemblage of Giardia among children under 5 years of age in Jimma, Southwest Ethiopia. Employing a case-control design, 606 children presenting with diarrhea at Jimma university medical center and Serbo Health Center were enrolled from December 2016 to July 2018 along with 617 matched controls without diarrhea. Giardia was detected and typed using real-time PCR. Univariate and multivariate regression analysis was performed. The total prevalence of Giardia was 41% (501/1223) and did not differ significantly between cases and controls (40% vs 42%). Prevalence increased by age, with the highest prevalence seen in children aged ≥ 25 months. Children without diarrhea with a history of diarrhea during the last month were more likely to be Giardia positive compared to children with no history diarrhea (OR 1.8 and 95%CI; 1.1-2.9). Regardless of current diarrhea symptoms, assemblage B predominated with 89%, followed by assemblage A (8%) and mixed infection assemblage A and B (3%). We report a high prevalence of Giardia by PCR detection in Jimma, Ethiopia, with assemblage B being predominant. There was a similar distribution of Giardia assemblages between children with and without diarrhea. Increasing age was a risk factor for Giardia infection. Community-based prevention and control strategies need to be employed to decrease the risk of giardia infection.

[Feline and canine giardiosis: An Update]

Giardia duodenalis is a facultative pathogenic intestinal parasite. Giardiosis in dogs and cats may appear with or without clinical signs. Typical signs include diarrhea with or without vomiting. The prevalence in young animals is high and may amount to up to 50%. There are 8 different genotypes (A - H), which are called assemblages. Assemblages C and D are most common in dogs and assemblage F most frequent in cats. However, animals may also be infected with the zoonotically effective assemblages A and B or exhibit mixed infections. The immunofluorescence test (IFA), the enzyme-linked immunosorbent assay (ELISA) and fecal centrifugation using zinc sulphate solution are currently recommended as diagnostic methods. Polymerase chain reaction (PCR) may be used to determine the corresponding assemblage. Approved treatments for giardiosis include fenbendazole and metronidazole. In addition, undertaking specific hygiene measures is warranted. Only animals showing clinical signs or those living in the same household with high-risk patients (e. g. immunosuppressed humans) are recommended to receive medication. The aim of treatment is clinical improvement of the diseased dogs and cats. Frequently, complete elimination of Giardia is not attained.

First report of prevalence and assemblage analysis of Giardia duodenalis in pigs from Guangxi Zhuang Autonomous Region, southern China

Giardia duodenalis is a common intestinal protozoan that can cause diarrhea and intestinal disease in animals and in humans. However, the prevalence and assemblages of G. duodenalis in pigs from Guangxi Zhuang Autonomous Region have not been reported. In this study, a total of 724 fecal samples (201 from nursery pigs, 183 from piglets, 175 from breeding pigs, and 165 from fattening pigs) were obtained in four areas of the region (Nanning, Yulin, Hezhou, and Guigang). The gene of the small subunit ribosomal RNA (SSU rRNA) of G. duodenalis was amplified by nested PCR. The results show that the prevalence of G. duodenalis in pigs was 3.59% (26/724), of which 14 samples belonged to assemblage A (53.85%) and 12 samples belonged to assemblage E (46.15%). The infection rates of G. duodenalis in Hezhou, Yulin, Nanning, and Guigang were 0%, 0.7%, 10.8% and 1.1%, respectively (χ2 = 45.616, p < 0.01); whereas 5.1% of breeding pigs, 6.0% of piglets, 2.4% of fattening pigs, and 1.0% of nursery pigs were infected with G. duodenalis (χ2 = 8.874, p < 0.05). The SSU rRNA-positive samples were amplified by PCR based on the β-giardin (bg), glutamate dehydrogenase (gdh), and triphosphate isomerase (tpi) genes. Ten, eight and seven positive samples were detected, respectively. Based on phylogenetic analysis of the three genetic loci sequences, a multilocus genotyping A1 was found. The findings of this study provide basic data for the development of prevention and control of G. duodenalis infections in pigs and humans in the Guangxi Zhuang Autonomous Region.

Advances in Protozoan Epigenetic Targets and Their Inhibitors for the Development of New Potential Drugs

Protozoan parasite diseases cause significant mortality and morbidity worldwide. Factors such as climate change, extreme poverty, migration, and a lack of life opportunities lead to the propagation of diseases classified as tropical or non-endemic. Although there are several drugs to combat parasitic diseases, strains resistant to routinely used drugs have been reported. In addition, many first-line drugs have adverse effects ranging from mild to severe, including potential carcinogenic effects. Therefore, new lead compounds are needed to combat these parasites. Although little has been studied regarding the epigenetic mechanisms in lower eukaryotes, it is believed that epigenetics plays an essential role in vital aspects of the organism, from controlling the life cycle to the expression of genes involved in pathogenicity. Therefore, using epigenetic targets to combat these parasites is foreseen as an area with great potential for development. This review summarizes the main known epigenetic mechanisms and their potential as therapeutics for a group of medically important protozoal parasites. Different epigenetic mechanisms are discussed, highlighting those that can be used for drug repositioning, such as histone post-translational modifications (HPTMs). Exclusive parasite targets are also emphasized, including the base J and DNA 6 mA. These two categories have the greatest potential for developing drugs to treat or eradicate these diseases.

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.

Burden and Epidemiology of Human Intestinal Giardia duodenalis Infection in Colombia: A Systematic Review

The genus Giardia is a unicellular protozoan able to parasitize both humans and animals. Cysts of Giardia can be found in soil samples, aquatic environments, food, and any surface that gets in contact with the feces of parasitized animals. The aim of this systematic review was to analyze the burden and epidemiology of Giardia infection in Colombia summarizing recent scientific reports and existing knowledge and to identify knowledge gaps that may be addressed in future investigations. This work follows the guidelines established by "Preferred Reporting Items for Systematic Reviews and Meta-Analyzes" (PRISMA). Published scientific literature from 1 January 2010 to 18 September 2022 was searched in six electronic scientific databases using the search terms: "Giardia" OR "Giardiasis" AND "Colombia". Twenty-three scientific articles were performed in 22 departments of Colombia at rural, urban, and a combination of rural and urban contexts. The prevalence of Giardia in the Colombian population was between 0.9 and 48.1% when the samples were analyzed with classical microscopy; the range of Giardia prevalence was even bigger (4.2-100%) when qPCR and nested PCR were used. The dominant Giardia assemblages found in Colombia were A and B, and most frequent subassemblages were AII, BIII, and BIV.

First report of Giardia duodenalis assemblage F in humans and dogs in southern Brazil

The present study aimed to molecularly characterize Giardia duodenalis from stool samples of humans, dogs, and cats. Molecular analyses were performed on 59 samples that tested positive for G. duodenalis on coproparasitological examinations. After extraction, the samples were first tested by nested polymerase chain reaction (n-PCR) analysis of the SSU-rRNA gene, and for the samples that were positive, the β-giardin, TPI, and GDH genes were analyzed. The amplicons obtained in the n-PCR of the β-giardin gene were subjected to PCR-restriction length polymorphism (RFLP) analysis and subsequent digestion with the enzyme HaeIII to differentiate the assemblages. Seven (11.8 %), 34 (57.7 %), and 18 (30.5 %) out of 59 samples were from humans, dogs, and cats, respectively. Nested-PCR results showed that 49.2 % (29/59) of samples were positive for the SSU-rRNA gene, with 42.9 % (3/7) of humans, 55.9 % (19/34) of dogs, and 38.9 % (7/18) of catsve. Of the other genes analyzed, β-giardin was amplified most frequently, in 34.5 % (10/29) of samples, followed by GDH in 27.6 % (8/29) of samples, and TPI in 10.3 % (3/29) of samples. Only one sample from a dog showed the amplification of all genes. PCR-RFLP analysis showed assemblage F in a human, dog, and cat samples; and assemblage C and D in dog samples. This is the first description of assemblage F in humans from Brazil and the first description of assemblage F in dogs. Further studies are needed to verify the frequency with which these infections occur, and provide information that will contribute to the molecular epidemiological understanding of giardiasis.

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.

Neglected Diseases—Parasitic Infections among Slovakian Children from Different Populations and Genotypes of Giardia duodenalis

Children are most prone to parasitic infections. The objectives of the study were to examine the occurrence of parasitic infections in children from different populations and to perform molecular characterization of human Giardia duodenalis isolates. We examined 631 stool samples from Roma and non-Roma children for the presence of parasitic developmental stages. Samples were collected from three eastern Slovakia districts. The ages of the children ranged from 1 months to 17 years. Subsequently, the molecular characterization of human G. duodenalis isolates by PCR detected triosephosphate isomerase (tpi) and beta-giardin (bg) genes was performed. The overall prevalence of parasitic infection was 19.8%. Ascaris lumbricoides eggs were the most frequent, with an occurrence of about 13.8%. G. duodenalis cysts were present in 6.3% of samples. G. duodenalis isolates obtained from 13 children were subjected to DNA sequencing with tpi and bg genes. Five isolates were categorized as bearing subassemblage BIII, the three isolates as subassemblage BIV, one person was infected with a mixture of subassemblages BIII and BIV, four children had subassemblage AII, and one isolate revealed a structure corresponding with subassemblage AI. Our work is proof that poverty and poor hygiene contribute the most to public health problems associated with neglected parasitic diseases.

Taxonomy and molecular epidemiology of Cryptosporidium and Giardia - a 50 year perspective (1971-2021)

The protozoan parasites Cryptosporidium and Giardia are significant causes of diarrhoea worldwide and are responsible for numerous waterborne and foodborne outbreaks of diseases. Over the last 50 years, the development of improved detection and typing tools has facilitated the expanding range of named species. Currently at least 44 Cryptosporidium spp. and >120 genotypes, and nine Giardia spp., are recognised. Many of these Cryptosporidium genotypes will likely be described as species in the future. The phylogenetic placement of Cryptosporidium at the genus level is still unclear and further research is required to better understand its evolutionary origins. Zoonotic transmission has long been known to play an important role in the epidemiology of cryptosporidiosis and giardiasis, and the development and application of next generation sequencing tools is providing evidence for this. Comparative whole genome sequencing is also providing key information on the genetic mechanisms for host specificity and human infectivity, and will enable One Health management of these zoonotic parasites in the future.

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.

First report of novel assemblages and mixed infections of Giardia duodenalis in human isolates from New Zealand

Giardia duodenalis (syn. G. intestinalis and G. lamblia) is a protozoan parasite that cause disease (giardiasis) in humans and other animals. The pathogen is classified into eight assemblages, further divided into sub-assemblages, based on genetic divergence and host specificities. There are two zoonotic subtypes known as assemblages A and B, whilst assemblages from C to H are mainly found in domesticated animals, rodents and marine mammals. Here, we report for the first time the presence of assemblage E and sub-assemblage AIII in human isolates from the South Island in New Zealand. We identified a > 99% nucleotide similarity of assemblage E and sub-assemblage AIII with sequences of the gdh gene available in GenBank from individual human samples collected in Dunedin and Christchurch, respectively. We also performed a deep sequencing approach to assess intra-host assemblage variation. The sample from Dunedin showed evidence of mixed assemblage E and zoonotic sub-assemblage BIV. The report of two novel assemblages and mixed infections provides insights into the genetic diversity, epidemiology and transmission dynamics of Giardia duodenalis in New Zealand.

Molecular detection of Cryptosporidium spp., Giardia duodenalis, and Enterocytozoon bieneusi in school children at the Thai-Myanmar border

Few data are available on the genetic identity of enteric protists Cryptosporidium spp., Giardia duodenalis, and Enterocytozoon bieneusi in humans in Thailand. In this study, 254 stool samples were collected from primary school children from Ratchaburi Province at the Thai-Myanmar border and examined for Cryptosporidium spp., G. duodenalis, E. bieneusi and Cyclospora cayetanensis using PCR techniques. The genotype identity of the pathogens was determined by DNA sequence analysis of the PCR products. Cryptosporidium felis was found in 1 stool sample, G. duodenalis in 19 stool samples, and E. bieneusi in 4 stool samples. For G. duodenalis, sub-assemblage AII was the dominant genotype, but one infection with assemblage F was found. The E. bieneusi genotypes found included known genotypes D and J, and one novel genotype (HPTM1). Cyclospora cayetanensis was not detected in any samples. Results of the preliminary study indicate that children at the Thai-Myanmar border from Ratchaburi Province, Thailand are infected with diverse zoonotic genotypes of Cryptosporidium spp., G. duodenalis, and E. bieneusi.

Occurrence of Giardia duodenalis in selected stations and tributary rivers of Laguna Lake, Philippines

Fecal pollution is a major contributor to the progressive degradation of Laguna Lake, the Philippines' largest inland lake used for aquaculture, recreation, and as a source of irrigation and domestic water. Consequently, intestinal parasites may be present in this body of water, posing risks to water safety and human health. This study was able to detect the protozoan parasite, Giardia duodenalis, in three Laguna Lake stations and seven tributary rivers in a 13-month monitoring period by PCR amplification of the small subunit ribosomal RNA (SSU rRNA) gene of Giardia cysts concentrated from water samples. The pathogen was present in 37.7% of tributary samples (n = 69) and 16.7% of lake samples (n = 36). Notable frequencies of detection were observed in four tributary rivers -Bagumbayan, Taguig (66.7%); Santa Rosa, Laguna (55.6%); San Cristobal, Cabuyao, Laguna (44.4%); and Biñan, Laguna (42.9%). All test SSU rRNA gene sequences were identified as human-infective genotypes of G. duodenalis predominated by Assemblage A (94.1%). Furthermore, analysis of the glutamate dehydrogenase (gdh) gene revealed the possible presence of mixed genotypes in at least two samples. These results support the pressing need to include protozoan pathogen monitoring in Laguna Lake and its tributaries to prevent Giardia infection in humans and animals. This study also recommends microbial source tracking to identify fecal pollution sources and aid in regulation of waste discharges into the lake and its tributaries.

Occurrence and molecular characterization of Cryptosporidium spp. and Giardia duodenalis among captive mammals in the Bangladesh National Zoo

Cryptosporidium and Giardia are protozoan parasites capable of causing gastrointestinal illness in humans and animals. The purpose of this research was to determine the occurrence, genetic characteristics, and zoonotic potential of Cryptosporidium spp. and Giardia duodenalis in captive mammals at the Bangladesh National Zoo. A total of 200 fresh fecal samples from 32 mammalian species were collected and examined for Cryptosporidium spp. using nested polymerase chain reaction (PCR) targeting the small subunit (SSU) rRNA gene and G. duodenalis targeting the β-giardin (bg), glutamate dehydrogenase (gdh), and triosephosphate isomerase (tpi) genes. The overall infection rates of Cryptosporidium and G. duodenalis among captive mammals in the zoo were 3.5% (7/200) and 5.5% (11/200), respectively. Five species/genotypes of Cryptosporidium (C. hominis, C. andersoni, C. muris, C. felis, and Cryptosporidium deer genotype) were identified. C. hominis was subtyped as IbA12G3 by sequence analysis of the glycoprotein 60 (gp60) gene. Multilocus genotyping of G. duodenalis revealed assemblages A, B, and D. Mixed infections of assemblages B and D and A and B were found in an Asiatic jackal and a Nilgiri langur, respectively. To our knowledge, this is the first report on the occurrence and genetic identity of the two parasites among zoo animals in Bangladesh. The results suggest that zoonotic Cryptosporidium spp. and G. duodenalis are maintained in and transmitted between captive mammals. Therefore, washing, cleaning, and disinfection measures should be implemented to reduce the spread of Cryptosporidium and G. duodenalis infections.

Prevalence and multi-locus genotyping of Giardia duodenalis in rabbits from Shaanxi province in northwestern China

Giardia duodenalis is an important parasite with veterinary and public health significance worldwide. The presence and zoonotic assemblages of G. duodenalis have previously been reported in rabbits. In this study, to understand the infection status of G. duodenalis in rabbits from Shaanxi province, a total of 537 fecal samples were collected from two breeds of rabbits in four age groups (<30 days, 31–90 days, 91–200 days and >200 days) from four geographical origins (Fengxiang, Yangling, Tongchuan, and Shanyang). The presence of G. duodenalis in these samples was assessed using molecular assays based on beta-giardin (bg). The glutamate dehydrogenase (gdh) and triosephosphate isomerase (tpi) loci were then amplified in the bg-positive samples for multi-locus genotype (MLG) analysis. The total prevalence of G. duodenalis in these rabbits was 3.54% (19/537). Giardia duodenalis infection was found in both breeds of rabbits, and in all farms and age groups, but with no statistically significant differences related to these factors (p > 0.05). Two assemblages, including B and E, were identified, with the former the predominant assemblage detected in both breeds, and in all age groups and farms. Sequence analysis revealed 2 (named as rbg1-2), 1 (named as rtpi1), and 2 (named as rgdh1-2) haplotypes at the gene loci of bg, tpi, and gdh, respectively, forming a multilocus genotype (MLG) of assemblage B (rbg1, rtpi1, and rgdh1). These findings reveal the significant zoonotic potential and genetic diversity of G. duodenalis in rabbits in Shaanxi Province, PR China.

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.

Global epidemiology of Giardia duodenalis infection in cancer patients: a systematic review and meta-analysis

Background

Application of chemotherapeutics in cancer patients may provide an immunosuppressive milieu, favourable for parasitic infections. Giardia duodenalis is an important zoonotic intestinal parasite responsible for diarrhoea in humans worldwide.

Methods

The present systematic review and meta-analysis was conducted to estimate the prevalence of G. duodenalis and respective odds ratios (ORs) in cancer patients around the globe. Four online databases—PubMed, Scopus, Web of Science and Google Scholar—were carefully explored for relevant literature without time limitation until 28 November 2020. Meta-analysis was done based on a random effects model to pool the estimations and define 95% confidence intervals (CIs).

Results

The overall weighted prevalence of G. duodenalis infection in cancer patients was calculated to be 6.9% (95% CI 0.5 to 9.3) globally, based on data from 32 studies. Although not statistically significant, eight case–control studies revealed that cancer patients were 1.24 times (95% CI 0.66 to 2.31; p=0.501) more exposed to G. duodenalis infection than healthy controls. Moreover, the prevalence of infection was not significantly associated with quantitative variables, including publication year (regression coefficient −0.0135, p=0.578), sample size (regression coefficient −0.0007, p=0.074) and human development index (regression coefficient −1.6263, p=0.419). Also, subgroup analysis of the pooled G. duodenalis infection was performed for publication year, World Health Organization regions, countries, continents, cancer types and country income.

Conclusions

Altogether, the epidemiology of G. duodenalis infection and its associated risk factors in immunocompromised individuals, especially cancer patients, is still open to question and deserves comprehensive investigations.

FELINE GIARDIASIS IN TURKEY: PREVALENCE AND GENETIC AND HAPLOTYPE DIVERSITY OF GIARDIA DUODENALIS BASED ON THE β-GIARDIN GENE SEQUENCE IN SYMPTOMATIC CATS

Giardia duodenalis is a common zoonotic protozoan parasite with a broad host distribution. The main objectives of the present study were to determine the prevalence of giardiasis and to reveal the genetic and haplotype diversity of G. duodenalis in symptomatic cats in Turkey. Fecal samples were collected from cats (n = 102) with diarrhea that were admitted to different pet clinics in the Central Anatolia region of Turkey. All samples were analyzed by microscopic examination (ME), rapid immunochromatographic test (ICT), and PCR targeting the β-giardin (bg) loci of the parasite. Phylogenetic, haplotype, and network analyses of G. duodenalis based on the bg gene were carried out. Overall, G. duodenalis was detected in 70/102 (68.6%) of the cats with diarrhea by ME (38/102, 37.3%), ICT (51/102, 50%), and PCR (30/102, 29.4%). According to sequence analyses of the bg gene region, all isolates were identified as G. duodenalis assemblage B. Haplotype analyses revealed 2 known and 8 novel haplotypes for G. duodenalis assemblage B. This study provides first prevalence and genetic and haplotype diversity data on G. duodenalis assemblage B from cats in Turkey.

Molecular Characterization of Giardia duodenalis in Children and Adults Sampled in Algeria

The molecular epidemiology of giardiasis in Africa remains unclear. A study was carried out across four hospitals in Algeria. A total of 119 fecal samples from 55 children, 37 adults, and 27 individuals of undetermined age, all scored positive for intestinal parasites by microscopy, and were screened by real-time PCR for Giardia. Molecular characterization of Giardia was performed by assemblage-specific PCR and PCR targeting the triose phosphate isomerase gene (tpi). Of the 119 samples, 80 (67%) were Giardia-positive by real-time PCR. For 48 moderately-highly real-time PCR-positive samples, tpi genotyping assigned 22 samples to Assemblage A and 26 to Assemblage B. Contrary to Assemblage A, Assemblage B exhibited substantial genetic diversity and allelic heterozygosity. Assemblage-specific PCR proved to be specific for discriminating Assemblage A or B but not as sensitive as tpi genotyping. We confirmed that real-time PCR is more sensitive than microscopy for detecting Giardia in stool samples and that robust amplification and sequencing of the tpi gene is feasible when moderate-to-strongly real-time PCR-positive samples are used. This study is one of the few performed in Africa providing genotyping data on Giardia infections in humans. Both assemblages A and B were commonly seen and not associated with specific sociodemographic data.

Molecular epidemiology of Giardia spp. in northern Vietnam: Potential transmission between animals and humans

Giardia spp. is detected frequently in humans and animals. Although many studies have been conducted on the epidemiology of giardiasis, there is a scarcity of information on the genetic diversity and the dynamics of transmission of Giardia spp. in Vietnam. The zoonotic potential of Giardia spp. remains elusive. The objective of this study was to determine the genetic diversity of Giardia spp. in both humans and livestock to assess the existence of a route of infection between livestock and humans. Our goal was to assess the role animals play in the epidemiology of human infection in northern Vietnam. In Hien Khanh commune in northern Vietnam, 311 households with 1508 residents were randomly selected for a diarrheal cohort study. Of these, 2120 human diarrheal samples were collected from 1508 residents in 2014 and 2017. Of these, non-diarrheal samples were cross-sectionally collected from 471 residents. At the same site, livestock samples from buffalo, dairy and beef cattle, pigs, and dogs were collected. All stool samples were examined for Giardia spp. by Direct Immunofluorescence Assay (DFA) using fluorescent microscope. DNA extraction, PCR analysis of the 3 genes (bg, gdh, tpi), and sequencing analysis were continuously carried out. A total of 23 animal stool samples, 8 human non-diarrheal samples, and 36 human diarrheal samples were Giardia spp. were positive by PCR using the bg and gdh genes. Giardia spp. assemblage AII and E were detected in both animal samples and human samples in this study site. The detection of assemblage E in human stool samples suggests the first human case report in Vietnam. We assume that the unexpected human infection of all Giardia assemblages including A, B, and E may be due to an environment contaminated with animal and human feces in this village.

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Giardia spp. assemblage A and E have been detected in buffalo, cattle and pigs, as well as in humans, while assemblage B appeared only in humans.

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This was the first report of assemblage E in humans in Vietnam.

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Zoonotic transmission of assemblage AII and E could not be excluded in our study site.

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In addition to the ‘animal-to-human’ route, there potentially might be transmission routes from ‘humans-to-humans’ and/or ‘humans-to-animals’ in this study site.

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The novel genotype belonging to assemblage AIII has been isolated only in buffalo.

Companion animals as a potential source of Giardia intestinalis infection in humans in the Czech Republic - A pilot study

Giardia intestinalis is a common enteric single-celled parasite infecting both humans and animals. Its eight morphologically identical but genetically distinct groups called assemblages differ from each other in host range. While assemblages A and B infect a wide range of hosts, including humans, the other assemblages (C to H) limit their host preferences to particular animal groups only. In companion animals as Giardia hosts, genotyping data have previously shown various results depending on pet species, location, environmental or breeding conditions, and the study design. To strengthen available epidemiological data from developed countries and to evaluate the role of pets in Giardia zoonotic transmission, we investigated Giardia-positive stool samples of three pet species (54 dogs, 18 cats, and 18 chinchillas) by a sequence-based analysis of three Giardia genes (β-giardin, glutamate dehydrogenase and triose phosphate isomerase). In dog samples, we confirmed assemblage C (21/54), assemblage D (32/54), and one case of a mixed infection C + D (1/54). In cats, we found assemblage F (16/18) and assemblage A, specifically sub-assemblage AI (2/18). All Giardia samples from chinchillas were characterised as assemblage B, specifically sub-assemblage BIV (18/18). These results indicate that in the Czech Republic, pet dogs may not represent a source of Giardia infection for humans because of the presence of only canid-specific genotypes C and D. In contrast, other pets, namely, chinchillas and, to a lesser extent, cats, may pose a potential risk of Giardia transmission to owners or breeders because they can host zoonotic Giardia genotypes.

Genetic analysis of Giardia duodenalis isolates from children of low-income families living in an economically successful region in Southeastern Brazil

Giardia duodenalis is one of the most important and widespread gastrointestinal parasites in the world. Despite its relevance as a causative agent of diarrhea, asymptomatic giardiasis occurs frequently, especially in low resources settings in which children are exposed to many risk factors. Based on microscopic examination and the polymerase chain reaction (PCR) amplification and sequencing of beta-giardin (bg), triose phosphate isomerase (tpi) and glutamate dehydrogenase (gdh) genes, we assessed G. duodenalis occurrence and genetic diversity in isolates of children attending a daycare center and living in low income families, in an economically successful region. Considering both, microscopic examination and PCR/sequencing methods, the overall prevalence of Giardia infection was 51.4%, with the highest frequency in children aged 1-4 years old (p<0.05). Genotyping of 50 isolates revealed that the assemblage A was found in 60% of the samples (30/50), followed by the assemblage B in 38% (19/50) and 2% of mixed-assemblage infections (1/50). At the sub-assemblage level, isolates genotyped as A were AII and among isolates B, BIII and BIV were identified. Both assemblages A and B were detected in children of all age groups, however assemblage A was more prevalent. The detection of anthroponotic assemblages and sub-assemblages (AII, BIII and BIV) reinforces human-to-human transmission, mainly in children of all age groups when they have not yet received toilet training, making them more vulnerable to infection.

Prevalence and multilocus genotyping of potentially zoonotic Giardia duodenalis in pigs in Shanghai, China

Giardia duodenalis is a common intestinal parasite in humans and other mammals, and it causes major public and veterinary health problems worldwide. China is a major pig-raising country, and studies on Giardia in pigs have important public health significance. The present study was conducted to investigate the prevalence of Giardia and assess its genetic characterization. A total of 93 samples were collected from two farms in Shanghai. The presence of Giardia was determined using PCR and sequence analysis of glutamate dehydrogenase, beta-giardin and triose phosphate isomerase genes. The average prevalence of G. duodenalis infection was 26.88% (25/93) in the pigs, with 28.13% (18/64) in farm 1 vs 24.14% (7/29) in farm 2. All the PCR-positive products were successfully sequenced, and assemblage E was more prevalent. Zoonotic assemblages A and B and canine-specific assemblage C were identified in farm 1, whereas, only assemblage E was detected in farm 2. Interestingly, two pig isolates showed 100% homology with human-derived isolates from Australia and China at the bg and tpi loci respectively. Pigs infected with Giardia infect humans by polluting the environment; whether pigs are a potential environmental source of the human pathogen in China requires more epidemiological data.