Zoonotic giardiasis: an update

Prevalence and Genotyping of Water- and Food-Borne Parasitic Protozoans (Giardia duodenalis and Cryptosporidium spp.) in Hospitalized Patients from Northwestern Romania

Giardia duodenalis and Cryptosporidium spp. are important zoonotic protozoan pathogens that infect the gastro-intestinal tract of numerous vertebrates, including humans, and both parasites are responsible for water- or food-borne outbreaks of disease worldwide. Although, globally, both parasites are highly prevalent, particularly in developing countries, epidemiological data from Romania are scarce, and genotyping has rarely been performed. The aims of the present study were to investigate the occurrence and genetic diversity of G. duodenalis and Cryptosporidium spp. in patients hospitalized in Northwestern Romania in relation to clinical and paraclinical presentation and to identify the relative frequency of non-specific symptoms and potential risk factors. Between June 2022 and January 2024, 426 fecal samples were screened for gastro-intestinal parasites by rapid tests and microscopical examination, further confirmed by PCR and sequencing. Giardia duodenalis was detected and characterized in 12 samples (2.82%), while Cryptosporidium parvum was confirmed in four samples (0.94%). A majority of positive patients were symptomatic and reported nausea and vomiting with a significantly higher frequency compared to negative ones. This study provides new insights into the epidemiological status and clinical implications of gastro-intestinal parasite species and genospecies in Romania that are necessary for an in-depth understanding of the potential zoonotic transmission and improvement of patient care.

Giardia telomeres and telomerase

Giardia duodenalis, the protozoan responsible for giardiasis, is a significant contributor to millions of diarrheal diseases worldwide. Despite the availability of treatments for this parasitic infection, therapeutic failures are alarmingly frequent. Thus, there is a clear need to identify new therapeutic targets. Giardia telomeres were previously identified, but our understanding of these structures and the critical role played by Giardia telomerase in maintaining genomic stability and its influence on cellular processes remains limited. In this regard, it is known that all Giardia chromosomes are capped by small telomeres, organized and protected by specific proteins that regulate their functions. To counteract natural telomere shortening and maintain high proliferation, Giardia exhibits constant telomerase activity and employs additional mechanisms, such as the formation of G-quadruplex structures and the involvement of transposable elements linked to telomeric repeats. Thus, this study aims to address the existing knowledge gap by compiling the available information (until 2023) about Giardia telomeres and telomerase, focusing on highlighting the distinctive features within this parasite. Furthermore, the potential feasibility of targeting Giardia telomeres and/or telomerase as an innovative therapeutic strategy is discussed.

Microscopy detection and molecular characterisation of Giardia duodenalis infection in outpatients seeking medical care in Egypt

Introduction

Giardiosis remains one of the most prevalent enteric parasitic infections globally. Earlier molecular-based studies conducted in Egypt have primarily focused on paediatric clinical populations and most were based on single genotyping markers. As a result, there is limited information on the frequency and genetic diversity of G. duodenalis infections in individuals of all age groups.

Methods

Individual stool samples (n = 460) from outpatients seeking medical care were collected during January-December 2021 in Kafr El-Sheikh governorate, northern Egypt. Initial screening for the presence of G. duodenalis was conducted by coprological examination. Microscopy-positive samples were further confirmed by real-time PCR. A multilocus sequence typing approach targeted amplification of the glutamate dehydrogenase (gdh), beta-giardin (bg), and triose phosphate isomerase (tpi) genes was used for genotyping purposes. A standardised epidemiological questionnaire was used to gather basic sociodemographic and clinical features of the recruited patients.

Results

Giardia duodenalis cysts were observed in 5.4% (25/460, 95% CI: 3.6-7.9) of the stool samples examined by conventional microscopy. The infection was more frequent in children under the age of 10 years and in individuals presenting with diarrhoea but without reaching statistical significance. Stool samples collected during the winter period were more likely to harbour G. duodenalis. All 25 microscopy-positive samples were confirmed by real-time PCR, but genotyping data was only available for 56.0% (14/25) of the isolates. Sequence analyses revealed the presence of assemblages A (78.6%, 11/14) and B (21.4%, 3/14). All assemblage A isolates were identified as sub-assemblage AII, whereas the three assemblage B sequences belonged to the sub-assemblage BIII. Patients with giardiosis presenting with diarrhoea were more frequently infected by the assemblage A of the parasite.

Conclusion

This is one of the largest epidemiological studies evaluating G. duodenalis infection in individuals of all age groups in Egypt. Our molecular data suggest that G. duodenalis infections in the surveyed population are primarily of anthropic origin. However, because assemblages A and B are zoonotic, some of the infections identified can have an animal origin. Additional investigations targeting animal (domestic and free-living) and environmental (water) samples are warranted to better understand the epidemiology of giardiosis in Egypt.

Prevalence and molecular characterization of Cryptosporidium spp., Enterocytozoon bieneusi, and Giardia duodenalis in dairy cattle in Ningxia, northwestern China

Cryptosporidium spp., Enterocytozoon bieneusi, and Giardia duodenalis are common intestinal pathogens that infect humans and animals. To date, research regarding these three protozoa in the Ningxia Hui Autonomous Region (Ningxia) has mostly been limited to a single pathogen, and comprehensive data on mixed infections are unavailable. This study aimed to evaluate the zoonotic potential of these three protozoa. In this study, small subunit ribosomal RNA (SSU rRNA) and 60 kDa glycoprotein (gp60) genes of Cryptosporidium; internal transcribed spacer (ITS) gene of E. bieneusi; and SSU rRNA, glutamate dehydrogenase (gdh), triosephosphate isomerase (tpi), and beta-giardin (bg) genes of G. duodenalis were examined. DNA extraction, polymerase chain reaction, and sequence analysis were performed on fecal samples collected from 320 dairy cattle at three intensive dairy farms in Ningxia in 2021 to determine the prevalence and genetic characteristics of these three protozoa. The findings revealed that 61.56% (197/320) of the samples were infected with at least one protozoan. The overall prevalence of Cryptosporidium was 19.38% (62/320), E. bieneusi was 41.56% (133/320), and G. duodenalis was 29.38% (94/320). This study identified four Cryptosporidium species (C. bovis, C. andersoni, C. ryanae, and C. parvum) and the presence of mixed infections with two or three Cryptosporidium species. C. bovis was the dominant species in this study, while the dominant C. parvum subtypes were IIdA15G1 and IIdA20G1. The genotypes of E. bieneusis were J, BEB4, and I alongside the novel genotypes NX1-NX8, all belonging to group 2, with genotype J being dominant. G. duodenalis assemblages were identified as assemblages E, A, and B, and a mixed infection involving assemblages A + E was identified, with assemblage E being the dominant one. Concurrently, 11 isolates formed 10 different assemblage E multilocus genotypes (MLGs) and 1 assemblage A MLG and assemblage E MLGs formed 5 subgroups. To the best of our knowledge, this is the first report on mixed infection with two or three Cryptosporidium species in cattle in Ningxia and on the presence of the C. parvum subtype IIdA20G1 in this part of China. This study also discovered nine genotypes of E. bieneusis and novel features of G. duodenalis assemblages in Ningxia. This study indicates that dairy cattle in this region may play a significant role in the zoonotic transmission of Cryptosporidium spp., E. bieneusi, and G. duodenalis.

Rabbits as reservoirs: An updated perspective of the zoonotic risk from Cryptosporidium and Giardia

Rabbits are highly abundant in many countries and can serve as reservoirs of diseases for a diversity of pathogens including the enteric protozoan parasites, Cryptosporidium and Giardia. Both parasites shed environmentally robust environmental stages (oo/cysts) and have been responsible for numerous waterborne outbreaks of diseases. Cryptosporidium hominis and C. parvum are responsible for most infections in humans, while Giardia duodenalis assemblages A and B, cause most human cases of giardiasis. Cryptosporidium cuniculus, the dominant species infecting rabbits, is the only spceies other than C. hominis and C. parvum to have caused a waterborne outbreak of gastritis, which occurred in the United Kingdom in 2008. This review examines the prevalence of Cryptosporidium and Giardia species in rabbits to better understand the public health risks of contamination of water sources with Cryptosporidium and Giardia oo/cysts from rabbits. Despite the abundance of C. cuniculus in rabbits, reports in humans are relatively rare, with the exception of the United Kingdom and New Zealand, and reports of C. cuniculus in humans from the United Kingdom have declined substantially since the 2008 outbreak. Subtyping of C. cuniculus has supported the potential for zoonotic transmission. Relatively few studies have been conducted on Giardia, but assemblage B dominates. However, improved typing methods are required to better understand the transmission dynamics of Giardia assemblages in rabbits. Similarly, it is not well understood if pet rabbits or contaminated water are the main source of C. cuniculus infections in humans. Well-planned studies using high-resolution typing tools are required to understand the transmission dynamics better and quantify the public health risk of Cryptosporidium and Giardia from rabbits.

Minimal zoonotic risk of cryptosporidiosis and giardiasis from frogs and reptiles

The zoonotic potential of the protist parasites Cryptosporidium spp. and Giardia duodenalis in amphibians and reptiles raises public health concerns due to their growing popularity as pets. This review examines the prevalence and diversity of these parasites in wild and captive amphibians and reptiles to better understand the zoonotic risk. Research on Giardia in both groups is limited, and zoonotic forms of Cryptosporidium or Giardia have not been reported in amphibians. Host-adapted Cryptosporidium species dominate in reptiles, albeit some reptiles have been found to carry zoonotic (C. hominis and C. parvum) and rodent-associated (C. tyzzeri, C. muris and C. andersoni) species, primarily through mechanical carriage. Similarly, the limited reports of Giardia duodenalis (assemblages A, B and E) in reptiles may also be due to mechanical carriage. Thus, the available evidence indicates minimal zoonotic risk associated with these organisms in wild and captive frogs and reptiles. The exact transmission routes for these infections within reptile populations remain poorly understood, particularly regarding the importance of mechanical carriage. Although the risk appears minimal, continued research and surveillance efforts are necessary to gain a more comprehensive understanding of the transmission dynamics and ultimately improve our ability to safeguard human and animal health.

Critters and contamination: Zoonotic protozoans in urban rodents and water quality

Rodents represent the single largest group within mammals and host a diverse array of zoonotic pathogens. Urbanisation impacts wild mammals, including rodents, leading to habitat loss but also providing new resources. Urban-adapted (synanthropic) rodents, such as the brown rat (R. norvegicus), black rat (R. rattus), and house mouse (Mus musculus), have long successfully adapted to living close to humans and are known carriers of zoonotic pathogens. Two important enteric, zoonotic protozoan parasites, carried by rodents, include Cryptosporidium and Giardia. Their environmental stages (oocysts/cysts), released in faeces, can contaminate surface and wastewaters, are resistant to common drinking water disinfectants and can cause water-borne related gastritis outbreaks. At least 48 species of Cryptosporidium have been described, with C. hominis and C. parvum responsible for the majority of human infections, while Giardia duodenalis assemblages A and B are the main human-infectious assemblages. Molecular characterisation is crucial to assess the public health risk linked to rodent-related water contamination due to morphological overlap between species. This review explores the global molecular diversity of these parasites in rodents, with a focus on evaluating the zoonotic risk from contamination of water and wasterwater with Cryptosporidium and Giardia oocysts/cysts from synanthropic rodents. Analysis indicates that while zoonotic Cryptosporidium and Giardia are prevalent in farmed and pet rodents, host-specific Cryptosporidium and Giardia species dominate in urban adapted rodents, and therefore the risks posed by these rodents in the transmission of zoonotic Cryptosporidium and Giardia are relatively low. Many knowledge gaps remain however, and therefore understanding the intricate dynamics of these parasites in rodent populations is essential for managing their impact on human health and water quality. This knowledge can inform strategies to reduce disease transmission and ensure safe drinking water in urban and peri‑urban areas.

The risk of wild birds contaminating source water with zoonotic Cryptosporidium and Giardia is probably overestimated

Cryptosporidium and Giardia are important waterborne protozoan parasites that are resistant to disinfectants commonly used for drinking water. Wild birds, especially wild migratory birds, are often implicated in the contamination of source and wastewater with zoonotic diseases, due to their abundance near water and in urban areas and their ability to spread enteric pathogens over long distances. This review summarises the diversity of Cryptosporidium and Giardia in birds, with a focus on zoonotic species, particularly in wild and migratory birds, which is critical for understanding zoonotic risks. The analysis revealed that both avian-adapted and zoonotic Cryptosporidium species have been identified in birds but that avian-adapted Cryptosporidium species dominate in wild migratory birds. Few studies have examined Giardia species and assemblages in birds, but the non-zoonotic Giardia psittaci and Giardia ardeae are the most commonly reported species. The identification of zoonotic Cryptosporidium and Giardia in birds, particularly C. parvum and G. duodenalis assemblages A and B in wild migratory birds, is likely due to mechanical carriage or spillback from birds co-grazing pastures contaminated with C. parvum from livestock. Therefore, the role of wild migratory birds in the transmission of zoonotic Cryptosporidium and Giardia to source water is likely overestimated. To address knowledge gaps, it is important to conduct more extensive studies on the prevalence of Cryptosporidium and Giardia in a broader range of migratory wild birds. There is also a need to investigate the extent to which zoonotic infections with C. hominis/C. parvum and G. duodenalis assemblages A and B are mechanical and/or transient, and to assess the load and viability of zoonotic oo/cysts shed in avian faeces. Understanding the contribution of birds to zoonoses is essential for effective disease surveillance, prevention, and control.

Evaluation of the Use of Singleplex and Duplex CerTest VIASURE Real-Time PCR Assays to Detect Common Intestinal Protist Parasites

Cryptosporidium spp., Giardia duodenalis and Entamoeba histolytica are species of protozoa- causing diarrhoea that are common worldwide, while Entamoeba dispar, Dientamoeba fragilis and Blastocystis sp. appear to be commensal parasites whose role in pathogenicity remains controversial. We conducted the clinical evaluation of five singleplex and one duplex CerTest VIASURE Real-Time PCR Assays against a large panel of positive DNA samples (n = 358), and specifically to Cryptosporidium spp. (n = 96), G. duodenalis (n = 115), E. histolytica (n = 25) E. dispar (n = 11), Blastocystis sp. (n = 42), D. fragilis (n = 37), and related parasitic phylum species such as Apicomplexa, Euglenozoa, Microsporidia and Nematoda. DNA samples were obtained from clinical stool specimens or cultured isolates in a national reference centre. Estimated diagnostic sensitivity and specificity values were 0.94-1 for Cryptosporidium spp., 0.96-0.99 for G. duodenalis, 0.96-1 for E. histolytica, 1-1 for E. dispar, and 1-0.99 for D. fragilis in the evaluated singleplex assays. In the duplex assay for the simultaneous detection of Blastocystis sp. and D. fragilis these values were 1-0.98 and 1-0.99, respectively. Measures of diagnostic precision for repeatability and reproducibility were found to be under acceptable ranges. The assays identified six Cryptosporidium species (C. hominis, C. parvum, C. canis, C. felis, C. scrofarum, and C. ryanae), four G. duodenalis assemblages (A, B, C, and F), and six Blastocystis subtypes (ST1-ST5, and ST8). The evaluated singleplex and duplex VIASURE Real-Time PCR assays provide sensitive, practical, and cost-effective choices to the molecular diagnosis of the main diarrhoea-causing intestinal protists in clinical microbiology and research laboratories.

Zoonotic Cryptosporidium and Giardia in marsupials-an update

Marsupials, inhabiting diverse ecosystems, including urban and peri-urban regions in Australasia and the Americas, intersect with human activities, leading to zoonotic spill-over and anthroponotic spill-back of pathogens, including Cryptosporidium and Giardia. This review assesses the current knowledge on the diversity of Cryptosporidium and Giardia species in marsupials, focusing on the potential zoonotic risks. Cryptosporidium fayeri and C. macropodum are the dominant species in marsupials, while in possums, the host-specific possum genotype dominates. Of these three species/genotypes, only C. fayeri has been identified in two humans and the zoonotic risk is considered low. Generally, oocyst shedding in marsupials is low, further supporting a low transmission risk. However, there is some evidence of spill-back of C. hominis into kangaroo populations, which requires continued monitoring. Although C. hominis does not appear to be established in small marsupials like possums, comprehensive screening and analysis are essential for a better understanding of the prevalence and potential establishment of zoonotic Cryptosporidium species in small marsupials. Both host-specific and zoonotic Giardia species have been identified in marsupials. The dominance of zoonotic G. duodenalis assemblages A and B in marsupials may result from spill-back from livestock and humans and it is not yet understood if these are transient or established infections. Future studies using multilocus typing tools and whole-genome sequencing are required for a better understanding of the zoonotic risk from Giardia infections in marsupials. Moreover, much more extensive screening of a wider range of marsupial species, particularly in peri-urban areas, is required to provide a clearer understanding of the zoonotic risk of Cryptosporidium and Giardia in marsupials.

Assemblage characterization of Giardia duodenalis in South Khorasan province, eastern Iran, using HRM real-time PCR method

BACKGROUND

Giardia duodenalis is a common parasitic protozoan causing gastrointestinal illness in humans worldwide. The genetic diversity of G. duodenalis is reflected through the identification of different assemblages. In this study, we aimed to determine the assemblages of G. duodenalis in eastern Iran using nested-PCR and high-resolution melting (HRM) real-time PCR methods.

METHODS

A total of 58 positive G. duodenalis, which were isolated from 1800 subjects, referred to medical center laboratories in South Khorasan province, eastern Iran, from April 2020 to March 2022, were included in this study. DNA was extracted and HRM real-time PCR was performed for assemblage characterization.

RESULTS

HRM real-time PCR successfully characterized all samples. Accordingly, out of 58 positive samples, 53 (91.36%) and 5 (8.62%) were identified as assemblage A and B, respectively.

CONCLUSIONS

Our findings showed that HRM real-time PCR was able to characterize the assemblages of G. duodenalis. In addition, our results suggest high prevalence of assemblage A in eastern region of Iran.

Prevalence and Multilocus Genotyping of Giardia duodenalis in Donkeys in Shanxi Province, North China

Giardia duodenalis is a ubiquitous flagellated protozoan, causing significant economic losses to animal husbandry and posing threats to public health. China ranks the world's sixth largest major producer of donkeys, rearing approximately 2.6 million donkeys in 2019, but limited investigation of G. duodenalis prevalence has been conducted in the past, and it is yet to be known whether donkeys in Shanxi Province are infected with G. duodenalis. In the present study, a total of 815 fecal samples collected from donkeys in representative regions of Shanxi Province, North China, were examined for G. duodenalis using nested PCR. Then, the assemblages and multilocus genotypes (MLGs) were examined based on three established loci: namely, β-giardin (bg), triosephosphate isomerase (tpi), and glutamate dehydrogenase (gdh). The overall prevalence of G. duodenalis in donkeys in Shanxi Province was 16.81% (137/815). The region was identified as the main risk factor for the observed difference in G. duodenalis prevalence in donkeys among the three study areas (χ2 = 21.611, p < 0.001). Assemblages A, E, and B were identified, with the latter as the predominant assemblage. Three MLGs (MLG-novel-1 to 3) were formed based on sequence variation among the three loci. The present study reveals the presence of G. duodenalis in donkeys in Shanxi Province, North China, for the first time, which not only enriches the data on the distribution of G. duodenalis in donkeys in China but also provides useful baseline data for planning control strategies against G. duodenalis infection in the sampled areas.

Assessment of potential zoonotic transmission of Giardia duodenalis from dogs and cats

Giardia duodenalis is one of the major causes of diarrhea among humans, especially in young children. Statistical analysis revealed that the pooled prevalence of G. duodenalis in humans, dogs, and cats was 9.72% (10,921/112383), 15.60% (7510/48140), and 14.53% (1125/7740), respectively. Unquestionably, the canine-specific assemblages C and D and the feline-specific assemblage F were the dominant genotypes in dogs and cats, respectively. Additionally, the prevalence of zoonotic G. duodenalis assemblages (A and B) in dogs and cats was 23.07% (875/3792) and 41.42% (169/408), respectively, implying that the potential transmission of G. duodenalis from dogs and cats to human infection cannot be ignored. The highest frequency of potentially zoonotic assemblages was found among working dogs (3.55%, 25/705) and the 1-5 age group (22.92%, 11/48). In summary, dogs and cats have a significant role in the zoonotic transmission of G. duodenalis due to their close contact with humans and the higher frequency presence of zoonotic assemblages. Further studies are necessary to explore the presence of G. duodenalis among humans and animals and in environmental samples. Researchers should adopt a one-health approach to gain a deeper understanding of G. duodenalis in dogs and cats and potential transmission routes to humans.

Prevalence of gastrointestinal parasites in captive mammals at Khon Kaen Zoo, Thailand

Background and Aim

Captive animals are susceptible to parasitic diseases due to the stress and confinement they experience. In addition, they can serve as reservoirs of zoonotic parasites that have the potential to infect humans. To investigate this possibility, we estimated the prevalence of gastrointestinal (GI) parasites in captive mammals at Khon Kaen Zoo, Thailand.

Materials and Methods

One hundred and forty-seven individual mammals (37 primates, 43 carnivores, 62 herbivores, and 5 rodents) were examined for parasitic infections by fecal examination daily for 3 consecutive days using the formalin-ethyl acetate concentration technique (FECT) and the agar plate culture method.

Results

According to FECT, the overall prevalence of GI parasites was 62.6% (92/147). Within animal groups, the numbers were as follows: 67.6% (25/37) in primates, 23.3% (10/43) in carnivores, 85.5% (53/62) in herbivores, and 80.0% (4/5) in rodents. Using the agar plate culture method, 21.43% (27/126) were positive for Strongyloides spp. and hookworm infections. The GI parasites identified belonged to three categories: protozoa (including Entamoeba histolytica species complex, Entamoeba coli, Giardia spp., coccidia, and ciliated protozoa), trematodes (minute intestinal flukes and rumen flukes), and nematodes (strongyle/hookworm, Strongyloides spp., Ascarididae, and Trichuris spp.).

Conclusion

The findings of this study indicate the prevalence of several GI parasites in zoo animals with the potential for transmission to humans, given the animals' close proximity to both visitors and animal caretakers.

How significant are bats as potential carriers of zoonotic Cryptosporidium and Giardia?

Bats are known to harbour various pathogens and are increasingly recognised as potential reservoirs for zoonotic diseases. This paper reviews the genetic diversity and zoonotic potential of Cryptosporidium and Giardia in bats. The risk of zoonotic transmission of Cryptosporidium from bats to humans appears low, with bat-specific Cryptosporidium genotypes accounting for 91.5% of Cryptosporidium-positive samples genotyped from bats worldwide, and C. parvum and C. hominis accounting for 3.4% each of typed positives, respectively. To date, there have only been sporadic detections of Giardia in bats, with no genetic characterisation of the parasite to species or assemblage level. Therefore, the role bats play as reservoirs of zoonotic Giardia spp. is unknown. To mitigate potential risks of zoonotic transmission and their public health implications, comprehensive research on Cryptosporidium and Giardia in bats is imperative. Future studies should encompass additional locations across the globe and a broader spectrum of bat species, with a focus on those adapted to urban environments.

Epizootiology and biological characteristics of echinococcosis in agricultural animals, dogs, wild carnivores, and rodents in the Western region of the Republic of Kazakhstan

Background and Aim

Echinococcosis is one of the most dangerous parasitic diseases common to humans and animals. In Kazakhstan, echinococcosis is widespread in animals. This study aimed to estimate the prevalence and biological characteristics of echinococcosis in agricultural animals, dogs, wild carnivores, and rodents in the Western region of the Republic of Kazakhstan.

Materials and Methods

The study analyzed slaughtered carcasses of cattle (2500), sheep (4200), pigs (250), horses (91), and camels (45). Furthermore, the study analyzed 144 dogs (herding, rural, and urban), 41 wild carnivores (wolves, red foxes, and corsac foxes), and 339 wild rodents (great gerbils, tamarisk jirds, little ground squirrels, yellow ground squirrels, and muskrats). Postmortem and vital examination methods were used in the helminthological studies of dogs, wild carnivores, and rodents. In agricultural animals, localization and intensity were determined by counting echinococcal cysts in parenchymatous organs.

Results

Extensiveness of invasion (EI) averaged 19.2% in cattle, 27.5% in sheep, 5.6% in pigs, and 13.3% in camels. Echinococcal cysts mainly affected the liver in sheep (45.4%) and the lungs in cattle (35.5%). The fertility of echinococcal cysts decreased with age in animals. Acephalocysts were registered mainly in cattle. The highest invasiveness of Echinococcus granulosus was found in herding dogs with an EI of 12.5%. Experimental infestations of dogs showed that maturation of echinococcal eggs occurred by days 36-40 and maturation of segments by day 50. Studies of wild carnivores and rodents showed the presence of E. granulosus (imago stage) in wolves, Alveococcus multilocularis (imago stage) in red foxes and corsac foxes, and A. multilocularis (larval stage) in great gerbils and muskrats.

Conclusion

Our data provide evidence of high epizootiological danger for the population and significant damage caused by E. granulosus to animal husbandry in the region. Studies on the spread of echinococcosis suggest the possibility of controlling the situation with human and animal diseases and show the importance of this issue.

Uncovering the effects of Giardia duodenalis on the balance of DNA viruses and bacteria in children's gut microbiota

The neglected parasitosis giardiasis is one of the most common intestinal infections worldwide, affecting mainly infants and young children. Giardia duodenalis may disturb the local microbiome, leading to intestinal ecosystem disorders, and altering different processes in the host, such as the immune response. Nevertheless, the alterations promoted by G. duodenalis on the human gut microbiome have not been thoroughly investigated. Here, we characterized the gut microbiota of G. duodenalis-infected children and determine the main alterations promoted by the parasite. To do so, fecal samples of 26 infected and four uninfected children aged 2 to 6 years old were processed for High Efficiency Microarray analysis, in order to describe their bacterial and viral profiles. Then, we quantified the total bacterial population by qPCR and assessed fecal calprotectin levels, which are closely related with gut inflammation. A total of 286 bacteria's species and 17 viruses' strains were identified. Our results revealed no statistically significant differences between G. duodenalis positive and negative groups in the taxa's phyla and families. However, bacterial species diversity was increased in children infected with G. duodenalis (p < 0.05), while the total number of bacteria was decreased (p < 0.05). Considering the virome analysis, 17 different strains were identified, 88% being bacteriophages. The correlation analysis revealed an important disruption in the balance of DNA virus and bacteria within the intestinal microbiota of Giardia-positive children. Our findings constitute the first description of the gut virome of Giardia-infected children and suggest that G. duodenalis infection exerts a modulatory effect on the gut microbiome, promoting local inflammation and altering the equilibrium of the parasite-microbiota-host triad. This highlights the importance of considering polymicrobial associations and understanding the broader context of giardiasis. Overall, our study provides new insights into the complex interactions between intestinal parasites and the microbiota, which may have implications for the development of novel therapeutic interventions in the future.

Dynamics of protozoal excretion in the faeces of calves during the first 28 days after arrival at the fattening farm indicate infection before regrouping and show poor temporal correlation with diarrhoea

BACKGROUND

Calves in dairy cattle production in Switzerland are transported to a fattening farm at the age of 3-5 weeks, and frequently suffer from diarrhoea within the first 14 days after arrival. To characterise the role of intestinal protozoa in this, we investigated the excretion dynamics of Eimeria, Cryptosporidium and Giardia during the first 28 days after the arrival and regrouping of calves at fattening farms.

METHODS

A total of 610 faecal samples from 122 calves (mean age 37.3 days; mean body weight 79.8 kg) were collected on seven different fattening farms during the first 28 days after the arrival and regrouping of the animals. The farms were visited between January and April (cold season; n = 4) and between June and August (warm season; n = 3). The samples were collected rectally on days 1, 4, 7, 14 and 28, assessed for consistency, and analysed using the McMaster method for quantitative determination of the number of Eimeria oocysts per gram of faeces (OPG), flotation for morphological differentiation of the unsporulated Eimeria oocysts, a concentration method for the semi-quantitative determination of Giardia cysts, and modified Ziehl-Neelsen staining for semi-quantitative determination of Cryptosporidium oocysts.

RESULTS

Overall, 50.8% (62/122) of the animals had diarrhoea during the study period. However, the faecal excretion of protozoal pathogens was neither associated with diarrhoea nor with body weight gain of the animals. Altogether, 90.2% (110/122) of the calves were Eimeria positive. Eimeria zuernii was excreted by 51 (41.8%) and Eimeria bovis by 68 (55.7%) animals. In the warm season more animals tested positive for Eimeria and OPGs were higher than in the cold season. There was no correlation between the age of the calves and the OPG values. Overall, 64.8% (79/122) of the calves excreted Eimeria oocysts within the first 7 days, indicating that they had been infected with the parasite on the dairy farm of origin. Eighty-nine calves (73.0%) excreted Giardia cysts, with more positive animals in the cold (80.3%) compared with the warm season (64.3%). Only Giardia duodenalis assemblage E was identified. Cryptosporidium oocysts were microscopically detected in 14 animals (11.5%) on five farms. Cryptosporidium spp. were present in a total of 12 animals, i.e. Cryptosporidium parvum in nine, Cryptosporidium ryanae in two, and Cryptosporidium bovis in one animal.

CONCLUSIONS

A better understanding of the temporal dynamics of protozoal infections in calves is helpful for the implementation of appropriate measures to protect the health of these animals at a critical phase in their lives. Our results indicate that factors other than those examined in the present study contributed to the onset of diarrhoea in the calves.

The Gut-Wrenching Effects of Cryptosporidiosis and Giardiasis in Children

Cryptosporidium species and Giardia duodenalis are infectious intestinal protozoan pathogens that cause alarming rates of morbidity and mortality worldwide. Children are more likely to have clinical symptoms due to their less developed immune systems and factors such as undernutrition, especially in low- and middle-income countries. The severity of the symptoms and clinical manifestations in children may vary from asymptomatic to life-threatening depending on the Cryptosporidium species/G. duodenalis strains and the resulting complex stepwise interactions between the parasite, the host nutritional and immunologic status, and the gut microbiome profile. Structural damages inflicted by both parasites to epithelial cells in the large and small intestines could severely impair children's gut health, including the ability to absorb nutrients, resulting in stunted growth, diminished neurocognitive development, and other long-term effects. Clinically approved cryptosporidiosis and giardiasis drugs have broad antimicrobial effects that have incomprehensible impacts on growing children's gut health.

Molecular Characterization of Cryptosporidium spp., Giardia duodenalis, Enterocytozoon bieneusi and Escherichia coli in Dairy Goat Kids with Diarrhea in Partial Regions of Shaanxi Province, China

Cryptosporidium spp., Giardia duodenalis, Enterocytozoon bieneusi and Escherichia coli are important diarrheal pathogens threatening the health of humans and various animals. Goats, especially pre-weaned goat kids, that carry these pathogens are important reservoirs related to human infection. In the present study, PCR-based sequencing techniques were applied to characterize Cryptosporidium spp., G. duodenalis, E. bieneusi and E. coli in 202 fecal samples of diarrheal kids for Guanzhong dairy goats from five locations in Shaanxi Province. The positive rates of Cryptosporidium spp., G. duodenalis, E. bieneusi and E. coli were 37.6% (76/202), 16.3% (33/202), 55.4% (112/202) and 78.7% (159/202) in these goat kids, respectively. Co-infection of two to four pathogens was found in 114 of 202 fecal samples. Significant differences (p < 0.001) in the positive rates of Cryptosporidium spp. and G. duodenalis were found among locations and age groups. Furthermore, two Cryptosporidium species (C. parvum and C. xiaoi), two G. duodenalis assemblages (E and A), nine E. bieneusi genotypes (CHG3, CHG1, BEB6, CHG5, CHG2, SX1, CHG28, COS-II and CD6) and two E. coli pathotypes (EPEC and EHEC) were identified. As for Cryptosporidium, two (IIdA19G1 and IIdA19G2) and two (XXIIIa and XXIIIg) subtypes were recognized in samples positive for C. parvum and C. xiaoi, respectively. A phylogenetic analysis based on the ITS locus of E. bieneusi indicated that all nine genotypes of E. bieneusi identified in this study belonged to the group 2. Four virulence factors (ehxA, eae, stx2 and stx1) of EPEC and EHEC were found in E. coli strains. Collectively, this study explored the colonization frequency of Cryptosporidium spp., G. duodenalis, E. bieneusi and E. coli in diarrheal kids of Guanzhong dairy goats in Shaanxi Province and expanded our understanding of the genetic composition and zoonotic potential of these pathogens in goats.

Absence of Giardia spp. in fecal samples from capybaras (Hydrochoerus hydrochaeris) inhabiting urban areas in the state of Mato Grosso do Sul, Brazil

Giardiasis is a major cause of diarrhea in humans and animals worldwide. Currently, there are nine species of Giardia, including Giardia duodenalis, which infects most vertebrates. The capybara (Hydrochoerus hydrochaeris) is the largest herbivorous rodent in the world. Although capybaras are hosts of several parasites of public health importance, including helminths and protozoa, there is a paucity of research on their zoonotic potential. We investigated the prevalence of Giardia spp. in populations of capybaras living in urban areas. Fecal samples from 247 capybaras were collected in Lagoa Maior, located in the municipality of Três Lagoas, and in Lago do Amor and Parque das Nações Indígenas, both located in the municipality of Campo Grande, state of Mato Grosso do Sul, Brazil. Fecal samples from capybaras originated from 133 adults (54%), 61 cubs (25%), and 53 juveniles (21%); 183 samples were collected in the rainy season and 64 in the dry season. Giardia spp. DNA was screened by the small-subunit ribosomal RNA (SSU rRNA) targeted PCR. Samples with DNA band sizes suggestive of Giardia spp. amplicons were examined by PCR targeting the glutamate dehydrogenase (GDH) and triosephosphate isomerase (TPI) genes. PCR amplicons were subjected to genetic sequencing. Nested PCR screening of the SSU rRNA gene revealed 16 samples showing faint DNA bands in gel electrophoresis with sizes similar to Giardia spp. amplicons. PCR amplicons of the SSU rRNA gene were analyzed by Sanger sequencing. Most of the sequencing reactions failed, and the chromatogram reads of some samples were ambiguous, suggesting nonspecific amplification. Therefore, all the capybara fecal samples were considered negative for Giardia spp. Two published studies on Giardia spp. in capybaras reported findings similar to ours, i.e., the absence or a low positivity rate for Giardia spp. However, further studies are needed to determine the possible role of capybaras in the epidemiology of giardiasis.

Genetic diversity and molecular diagnosis of Giardia

Giardia is a genus of flagellated protozoan parasites that infect the small intestine of humans and animals, causing the diarrheal illness known as giardiasis. Giardia exhibits significant genetic diversity among its isolates, which can have important implications for disease transmission and clinical presentation. This diversity is influenced by the coevolution of Giardia with its host, resulting in the development of unique genetic assemblages with distinct phenotypic characteristics. Although panmixia has not been observed, some assemblages appear to have a broader host range and exhibit higher transmission rates. Molecular diagnostic methods enable researchers to examine the genetic diversity of Giardia populations, enhancing our understanding of the genetic diversity, population structure, and transmission patterns of this pathogen and providing insights into clinical presentations of giardiasis.

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

Blastocystis spp., Enterocytozoon bieneusi, and Giardia duodenalis are three common zoonotic intestinal parasites that cause severe diarrhea and enteric diseases. Leizhou black goats are characterized by a high reproductive rate, fast growth, and good meat quality, making them one of the pre-eminent goat breeds in China. Goats are reportedly common reservoirs of these three intestinal pathogens, but no information on their prevalence or genotypic distributions in black goats in Guangdong Province, China, is available. A total of 226 fecal samples were collected from goats in Zhanjiang city and genomic DNA was extracted from them. The presence of the three pathogens was detected using nested PCR targeting the sequences encoding SSU rRNA (Blastocystis spp.), the internal transcribed spacer of rRNA (ITS; E. bieneusi), as well as beta-giardin, glutamate dehydrogenase, and triosephosphate isomerase (G. duodenalis). All PCR products were sequenced to determine the species and genotypes of the organisms. The total prevalence rates of Blastocystis spp., E. bieneusi, and G. duodenalis were 33.63% (76/226), 17.70% (40/226), and 24.78% (56/226), respectively. Four subtypes of Blastocystis spp. were detected: ST5 (n = 6), ST10 (n = 50), ST14 (n = 14), and ST21 (n = 6). Among them, ST10 was the dominant genotype, accounting for 65.79% of strains, followed by the genotypes ST14 (18.42%), zoonotic ST5 (7.89%), and ST21 (7.89%). Four genotypes of E. bieneusi were detected: CHG3 (n = 32), CM21 (n = 4), CHG1 (n = 2), and ET-L2 (n = 2). Among these, CHG3 was the dominant genotype. Assemblage E (n = 54) and concurrent assemblages A and E (n = 2) were identified in the G. duodenalis-positive goats using multilocus genotyping. Blastocystis spp., E. bieneusi, and G. duodenalis infections were common in Leizhou black goats, all of which have zoonotic genotypes, indicating the potential risk of zoonotic transmission. Our results provide basic data for the prevention and control of these three intestinal pathogens. Further studies are required to better understand their genetic characteristics and zoonotic potential in Guangdong Province.

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

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

Exploring genetic variability of Giardia duodenalis and Enterocytozoon bieneusi in raw vegetables and fruits: implications for food safety and public health in Mozambique

Giardia duodenalis and Enterocytozoon bieneusi are etiological agents of enteric diseases characterized by diarrhea that can progress to chronicity in humans, especially in children and in immunocompromised patients. This study aims to assess the genetic pattern of G. duodenalis and E. bieneusi detected in vegetables and fruits commercialized in Maputo markets, Mozambique and determine their public health importance. Eight study points were sampled: a farmer zone, a wholesale, four retail markets, and two supermarkets in Maputo city, where eight types of horticultural products were purchased. Using nested-PCR methods, 2.8% (9/321) and 1.3% (4/321) of samples monitored were positive for G. duodenalis and E. bieneusi, respectively. Based on the analysis of the β-giardin and ITS rRNA sequences of G. duodenalis and E. bieneusi detected, respectively, four different sequences of G. duodenalis (three novel sequences: BgMZ1, BgMZ2, and BgMZ3, and one known sequence) all from assemblage B and three genotypes of E. bieneusi (two novel sequences: EbMZ4 and EbMZ5, and one known sequence: KIN-1) from group 1. These microorganisms were found and characterized for the first time in horticultural products in Maputo markets. All identified G. duodenalis and E. bieneusi display high genetic similarity within their β-giardin and ITS rRNA sequences, respectively, having been clustered into assemblages and genotypes with high zoonotic transmission potential. Our study may represent a relevant step in the understanding of these intestinal pathogens in association with fresh vegetables and fruits for human consumption, for a better and broader "One Health" approach.

A shotgun metagenomic analysis of the fecal microbiome in humans infected with Giardia duodenalis

BACKGROUND

The mechanisms underlying the clinical outcome disparity during human infection with Giardia duodenalis are still unclear. In recent years, evidence has pointed to the roles of host factors as well as parasite's genetic heterogeneity as major contributing factors in the development of symptomatic human giardiasis. However, it remains contested as to how only a small fraction of individuals infected with G. duodenalis develop clinical gastrointestinal manifestations, whereas the majority of infected individuals remain asymptomatic. Here, we demonstrate that diversity in the fecal microbiome correlates with the clinical outcome of human giardiasis.

METHODS

The genetic heterogeneity of G. duodenalis clinical isolates from human subjects with asymptomatic and symptomatic giardiasis was determined using a multilocus analysis approach. We also assessed the genetic proximity of G. duodenalis isolates by constructing phylogenetic trees using the maximum likelihood. Total genomic DNA (gDNA) from fecal specimens was utilized to construct DNA libraries, followed by performing paired-end sequencing using the HiSeq X platform. The Kraken2-generated, filtered FASTQ files were assigned to microbial metabolic pathways and functions using HUMAnN 3.04 and the UniRef90 diamond annotated full reference database (version 201901b). Results from HUMAnN for each sample were evaluated for differences among the biological groups using the Kruskal-Wallis non-parametric test with a post hoc Dunn test.

RESULTS

We found that a total of 8/11 (72.73%) human subjects were infected with assemblage A (sub-assemblage AII) of G. duodenalis, whereas 3/11 (27.27%) human subjects in the current study were infected with assemblage B of the parasite. We also found that the parasite's genetic diversity was not associated with the clinical outcome of the infection. Further phylogenetic analysis based on the tpi and gdh loci indicated that those clinical isolates belonging to assemblage A of G. duodenalis subjects clustered compactly together in a monophyletic clade despite being isolated from human subjects with asymptomatic and symptomatic human giardiasis. Using a metagenomic shotgun sequencing approach, we observed that infected individuals with asymptomatic and symptomatic giardiasis represented distinctive microbial diversity profiles, and that both were distinguishable from the profiles of healthy volunteers.

CONCLUSIONS

These findings identify a potential association between host microbiome disparity with the development of clinical disease during human giardiasis, and may provide insights into the mechanisms by which the parasite induces pathological changes in the gut. These observations may also lead to the development of novel selective therapeutic targets for preventing human enteric microbial infections.

Ultrastructural Alterations of the Human Pathogen Giardia intestinalis after Drug Treatment

This review presents the main cell characteristics altered after in vitro incubation of the parasite with commercial drugs used to treat the disease caused by Giardia intestinalis. This important intestinal parasite primarily causes diarrhea in children. Metronidazole and albendazole are the primary compounds used in therapy against Giardia intestinalis. However, they provoke significant side effects, and some strains have developed resistance to metronidazole. Benzimidazole carbamates, such as albendazole and mebendazole, have shown the best activity against Giardia. Despite their in vitro efficacy, clinical treatment with benzimidazoles has yielded conflicting results, demonstrating lower cure rates. Recently, nitazoxanide has been suggested as an alternative to these drugs. Therefore, to enhance the quality of chemotherapy against this parasite, it is important to invest in developing other compounds that can interfere with key steps of metabolic pathways or cell structures and organelles. For example, Giardia exhibits a unique cell structure called the ventral disc, which is crucial for host adhesion and pathogenicity. Thus, drugs that can disrupt the adhesion process hold promise for future therapy against Giardia. Additionally, this review discusses new drugs and strategies that can be employed, as well as suggestions for developing novel drugs to control the infection caused by this parasite.

Role of rodents in the zoonotic transmission of giardiasis

Four species of Giardia out of nine have been identified in rodents based on molecular data: G. muris, G. microti, G. cricetidarum, and G. duodenalis. A total of seven G. duodenalis assemblages (A, B, C, D, E, F, G) have been identified in rodents to date. The zoonotic assemblages A and B are responsible for 74.88% (480/641) of the total identified genotypes in rodents by statistic. For sub-assemblage A in humans, AII is responsible for 71.02% (1397/1967) of the identified sub-assemblages, followed by AI with 26.39% (519/1967) and AIII with 1.17% (23/1967), indicating a significantly greater zoonotic potential for G. duodenalis infections in humans originating from animals. For sub-assemblages of type A in rodents, AI was identified in 86.89% (53/61), and AII in 4.92% (3/61). For assemblage B, 60.84% (390/641) were identified in rodents as having zoonotic potential to humans. In environmental samples, the zoonotic assemblages A and B were responsible for 83.81% (533/636) in water samples, 86.96% (140/161) in fresh produce samples, and 100% (8/8) in soil samples. The same zoonotic potential assemblage A or B simultaneously identified in humans, rodents, and environment samples had potential zoonotic transmission between humans and animals via a synanthropic environment. The infections and zoonotic potential for G. duodenalis were higher in farmed rodents and pet rodents than that in zoo, lab, and wild rodents. In conclusion, the role of rodents in zoonotic transmission of giardiasis should be noticed. In addition to rodents, dogs, cats, wild animals, and livestock could be involved in the zoonotic transmission cycle. This study aims to explore the current situation of giardiasis in rodents and seeks to delineate the role of rodents in the zoonotic transmission of giardiasis from the One Health perspective.

A potential role for Giardia chaperone protein GdDnaJ in regulating Giardia proliferation and Giardiavirus replication

BACKGROUND

Giardia duodenalis (referred to as Giardia) is a flagellated binucleate protozoan parasite, which causes one of the most common diarrheal diseases, giardiasis, worldwide. Giardia can be infected by Giardiavirus (GLV), a small endosymbiotic dsRNA virus belongs to the Totiviridae family. However, the regulation of GLV and a positive correlation between GLV and Giardia virulence is yet to be elucidated.

METHODS

To identify potential regulators of GLV, we performed a yeast two-hybrid (Y2H) screen to search for interacting proteins of RdRp. GST pull-down, co-immunoprecipitation and bimolecular fluorescence complementation (BiFC) assay were used to verify the direct physical interaction between GLV RdRp and its new binding partner. In addition, their in vivo interaction and colocalization in Giardia trophozoites were examined by using Duolink proximal ligation assay (Duolink PLA).

RESULTS

From Y2H screen, the Giardia chaperone protein, Giardia DnaJ (GdDnaJ), was identified as a new binding partner for GLV RdRp. The direct interaction between GdDnaJ and GLV RdRp was verified via GST pull-down, co-immunoprecipitation and BiFC. In addition, colocalization and in vivo interaction between GdDnaJ and RdRp in Giardia trophozoites were confirmed by Duolink PLA. Further analysis revealed that KNK437, the inhibitor of GdDnaJ, can significantly reduce the replication of GLVs and the proliferation of Giardia.

CONCLUSION

Taken together, our results suggested a potential role of GdDnaJ in regulating Giardia proliferation and GLV replication through interaction with GLV RdRp.

The Role of Veterinarians in Managing Community Cats: A Contextualized, Comprehensive Approach for Biodiversity, Public Health, and Animal Welfare

Homeless cats are a major problem in Europe, with hundreds of thousands abandoned every year. While many die, others can adapt to a lifestyle of roaming freely and establish community cat populations that tend to cluster together in groups. These groups of cats are typically found in urban areas that offer food and shelter to the cats. Animal welfare organizations often care for these cats, providing them with food, shelter, and medical attention. Despite this, conflicts can arise due to the presence of free-roaming cats, with some individuals advocating for drastic measures such as trapping and killing the cats to reduce their populations. However, it is essential to note that such methods are frequently illegal, inhumane, and ultimately ineffective in most situations. A thorough assessment of the impact of cats on a particular natural area requires a comprehensive cat census, a detailed study of the species being preyed upon, and an investigation into the prevalence of zoonotic or epizootic diseases. Moreover, veterinary experts assert that the public health risks associated with cats are often overstated. This article aims to provide a nuanced perspective on the impact of cats on biodiversity in natural areas, while also discussing their role in transmitting the main zoonotic diseases identified in European countries in recent years, with a particular focus on Spain. Effective cat control programs should focus on non-lethal methods such as trap-neuter-return (TNR) and adoption. TNR has proven to be the most effective and humane method of controlling the free-roaming cat population, but its effectiveness is influenced by several factors, including adoption programs and public education on responsible pet ownership. According to Spanish veterinarians, sustainable and science-based solutions such as TNR programs are the best way to achieve population control of free-roaming cats. The veterinary profession should raise awareness regarding sterilization, vaccination, and identification of cats and the consequences of abandonment. They oppose lethal control and removal of cats from the environment, which are ineffective and unethical methods. To promote animal welfare, veterinary professionals must collaborate with public administrations to implement long-term, sustainable solutions to the problem of cat overpopulation. Greater social awareness regarding the importance of sterilization and identification to prevent abandonment and reduce the number of free-roaming cats is also needed. Despite the challenges presented by homeless cat populations in Spain and the rest of Europe, there are many reasons for optimism. Animal welfare organizations and veterinary professionals are actively collaborating to develop humane and effective solutions to manage community cats, including programs such as TNR and adoption. Furthermore, these initiatives are gaining momentum and support from emerging laws and regulations, such as the recent Spanish animal welfare law. Through these efforts, we can reduce the number of free-roaming cats and improve their quality of life.

Occurrence and limited zoonotic potential of Cryptosporidium spp., Giardia duodenalis, and Balantioides coli infections in free-ranging and farmed wild ungulates in Spain

Little information is currently available on the occurrence and molecular diversity of the enteric protozoan parasites Cryptosporidium spp., Giardia duodenalis, and Balantioides coli in wild ungulates and the role of these host species as potential sources of environmental contamination and consequent human infections. The presence of these three pathogens was investigated in eight wild ungulate species present in Spain (genera Ammotragus, Capra, Capreolus, Cervus, Dama, Ovis, Rupicapra, and Sus) by molecular methods. Faecal samples were retrospectively collected from free-ranging (n = 1058) and farmed (n = 324) wild ungulates from the five Spanish bioregions. Overall infection rates were 3.0% (42/1382; 95% CI: 2.1-3.9%) for Cryptosporidium spp., 5.4% (74/1382; 95% CI: 4.2-6.5%) for G. duodenalis, and 0.7% (9/1382; 95% CI: 0.3-1.2%) for B. coli. Cryptosporidium infection was detected in roe deer (7.5%), wild boar (7.0%) and red deer (1.5%), and G. duodenalis in southern chamois (12.9%), mouflon (10.0%), Iberian wild goat (9.0%), roe deer (7.5%), wild boar (5.6%), fallow deer (5.2%) and red deer (3.8%). Balantioides coli was only detected in wild boar (2.5%, 9/359). Sequence analyses revealed the presence of six distinct Cryptosporidium species: C. ryanae in red deer, roe deer, and wild boar; C. parvum in red deer and wild boar; C. ubiquitum in roe deer; C. scrofarum in wild boar; C. canis in roe deer; and C. suis in red deer. Zoonotic assemblages A and B were detected in wild boar and red deer, respectively. Ungulate-adapted assemblage E was identified in mouflon, red deer, and southern chamois. Attempts to genotype samples positive for B. coli failed. Sporadic infections by canine- or swine-adapted species may be indicative of potential cross-species transmission, although spurious infections cannot be ruled out. Molecular evidence gathered is consistent with parasite mild infections and limited environmental contamination with (oo)cysts. Free-ranging wild ungulate species would not presumably play a significant role as source of human infections by these pathogens. Wild ruminants do not seem to be susceptible hosts for B. coli.

Meta-analysis of the prevalence of Giardia duodenalis in sheep and goats in China

Giardia duodenum (G. duodenalis) can cause giardiasis and infect a variety of hosts. So far, there have been no detailed data regarding the positive rate of G. duodenalis in sheep and goats in China. Here, a systematic literature review was carried out to investigate the epidemiology of G. duodenalis in sheep and goats in China. To perform the meta-analysis, the databases CNKI, VIP, WanFang, PubMed, Web of science and ScienceDirect were employed for screening studies related to the prevalence of G. duodenalis in sheep and goats in China. The total prevalence of G. duodenalis in sheep and goats was estimated to be 7.00% (95% CI: 4.00-10.00). In the age subgroup, the prevalence of G. duodenalis in sheep and goats of >12 months (11.29%; 95% CI: 8.08-14.97) was higher than that in sheep and goats of ≤12 months (7.57%; 95% CI: 3.95-12.24). An analysis based on seasons showed that the prevalence of G. duodenalis in sheep and goats was higher in summer (11.90%; 95% CI: 0.50-35.05) than that in other seasons. The prevalence of G. duodenalis in sheep and goats after 2016 was 8.57% (95% CI: 5.34-11.79), which was higher than others. The highest prevalence of G. duodenalis in sheep and goats was 13.06% (95% CI: 6.26-19.86) recorded in Southwestern China. The prevalence of Giardia infection in sheep (7.28%; 95% CI: 2.30-14.73) was higher than that in goats (5.43%; 95% CI: 2.73-8.98). The NOAA's National Center for Environmental Information (https://gis.ncdc.noaa.gov/maps/ncei/cdo/monthly) was used to extract relevant geoclimatic data (latitude, longitude, elevation, temperature, precipitation, humidity, and climate). By analyzing the data of each subgroup, it was shown that region, genetype, and climate were potential risk factors for giardiasis prevalence in sheep and goats. Based on the analysis of common factors and geographical factors, it is recommended to strengthen effective management measures (e.g. ventilation and disinfection in warm and humid areas) and formulate relevant policies according to local conditions. Breeders should strengthen the detection of G. duodenalis in sheep and goats, customize corresponding control measures according to the diet and living habits of sheep and goats, and strengthen the protection of sheep and lamb calves, so as to reduce the incidence rate and reduce the economic loss of China's animal husbandry.

A One-Year Retrospective Analysis of Viral and Parasitological Agents in Wildlife Animals Admitted to a First Aid Hospital

This study aimed to provide information on the presence and frequency of viral and parasitic agents in wildlife presented to a Veterinary Teaching Hospital in 2020-2021. Serum and faecal samples were collected from 50 rescued animals (roe deer, fallow deer, foxes, badgers, pine martens, and porcupines) and examined by serological, molecular, and parasitological techniques. Transtracheal wash (TTW) was also collected post-mortem from roe deer. Overall, the results of the different techniques showed infections with the following viral and parasitic agents: Bovine Viral Diarrhea Virus, Small Ruminant Lentiviruses, Kobuvirus, Astrovirus, Canine Adenovirus 1, Bopivirus, gastrointestinal strongyles, Capillaria, Ancylostomatidae, Toxocara canis, Trichuris vulpis, Hymenolepis, Strongyloides, Eimeria, Isospora, Dictyocaulus, Angiostrongylus vasorum, Crenosoma, Dirofilaria immitis, Neospora caninum, Giardia duodenalis, and Cryptosporidium. Sequencing (Tpi locus) identified G. duodenalis sub-assemblages AI and BIV in one roe deer and one porcupine, respectively. Adult lungworms collected from the TTW were identified as Dictyocaulus capreolus (COX1 gene). This is the first molecular identification of G. duodenalis sub-assemblage AI and D. capreolus in roe deer in Italy. These results show a wide presence of pathogens in wild populations and provide an overview of environmental health surveillance.

High Diversity of Giardia duodenalis Assemblages and Sub-Assemblages in Asymptomatic School Children in Ibadan, Nigeria

Giardia duodenalis is a significant contributor to the burden of diarrheal disease in sub-Saharan Africa. This study assesses the occurrence and molecular diversity of G. duodenalis and other intestinal parasites in apparently healthy children (n = 311) in Ibadan, Nigeria. Microscopy was used as a screening method and PCR and Sanger sequencing as confirmatory and genotyping methods, respectively. Haplotype analyses were performed to examine associations between genetic variants and epidemiological variables. At microscopy examination, G. duodenalis was the most prevalent parasite found (29.3%, 91/311; 95% CI: 24.3–34.7), followed by Entamoeba spp. (18.7%, 58/311; 14.5–23.4), Ascaris lumbricoides (1.3%, 4/311; 0.4–3.3), and Taenia sp. (0.3%, 1/311; 0.01–1.8). qPCR confirmed the presence of G. duodenalis in 76.9% (70/91) of the microscopy-positive samples. Of them, 65.9% (60/91) were successfully genotyped. Assemblage B (68.3%, 41/60) was more prevalent than assemblage A (28.3%, 17/60). Mixed A + B infections were identified in two samples (3.3%, 2/60). These facts, together with the absence of animal-adapted assemblages, suggest that human transmission of giardiasis was primarily anthroponotic. Efforts to control G. duodenalis (and other fecal-orally transmitted pathogens) should focus on providing safe drinking water and improving sanitation and personal hygiene practices.

Potential Zoonotic Transmission of Giardia duodenalis between Children and Calves in Bangladesh

Giardia duodenalis is a zoonotic protozoan parasite that causes gastrointestinal illness in humans and livestock. We studied the genetic diversity of G. duodenalis in children and calves from Bangladesh to determine its zoonotic potential. Fecal samples collected from children (299) and calves (699) were screened with nested PCR with primers targeting the ssu rRNA gene for G. duodenalis. Positive samples were further multilocus genotyped using the β-giardin (bg), glutamate dehydrogenase (gdh), and triose phosphate isomerase (tpi) genes. The overall infection rate of G. duodenalis was 21.1% (63/299) in children and 5.7% (40/699) in calves. There were no significant differences in infection with G. duodenalis among age groups, sex, and study areas in children and calves. Multilocus genotyping (MLG) of human G. duodenalis identified zoonotic assemblages A (34.0%, 18/53) and B (50.9%, 27/53) and a so-called ruminant-specific assemblage E (11.3%, 6/53), as well as two mixed assemblages, B/D (1/53) and B/E (1/53). Assemblage E predominated in calves (82.3%, 28/34), followed by assemblages A (11.8%, 4/34) and B (5.9%, 2/34). Overall, zoonotic assemblages A, B, and E were found in 6.0% (18/299), 9.0% (27/299), and 2.0% (6/299) of the children’s stool samples, respectively, and 0.6% (4/699), 0.3% (2/699), and 4.0% (28/699) of the calf fecal samples, respectively. Although there was a difference in the distribution of subassemblages in humans (mostly AII) and calves (mostly AI), the zoonotic assemblages A, B, and E present in both children and calves suggest the potential for zoonotic transmission of G. duodenalis. This molecular study highlights the fact that G. duodenalis infections were common in the study areas, with potential zoonotic transmission between children and calves, implying that cattle might play a role in G. duodenalis zoonotic transmission.

Circulating in Wild Small Mammals from Portugal

Cryptosporidium spp. and Giardia spp. are important diarrhea-causing protozoan parasites worldwide that exhibit broad host ranges. Wild small mammals can harbor host-adapted and potentially zoonotic species of both parasites. The aim of this study was to investigate Cryptosporidium spp. and Giardia spp. in wild rodents and shrews in Portugal, focusing on the protist's occurrence and genetic diversity. Molecular screening by PCR at the small subunit (SSU) rRNA gene locus of 290 fecal samples from wood mice (Apodemus sylvaticus), southwestern water voles (Arvicola sapidus), Cabrera's voles (Microtus cabrerae), Lusitanian pine voles (Microtus lusitanicus), Algerian mice (Mus spretus) and greater white-toothed shrews (Crocidura russula) in Northeast Portugal revealed the low occurrence of Cryptosporidium spp. (1%) and high occurrence of Giardia spp. (32.8%). The analysis revealed that "species" was the only significant factor associated with the increasing probability of Giardia spp. infection, with the highest prevalence reported in southwestern water voles and Lusitanian pine voles. Cryptosporidium and Giardia species determination at the SSU rRNA gene locus revealed C. muris and G. microti as the only circulating species, respectively. Subtyping of the glutamate dehydrogenase (gdh) and beta-giardin (bg) genes provided evidence of the high genetic diversity within the G. microti clade. This study suggests that rodent-adapted G. microti occurs to a large extent in cricetid hosts and supports the limited role of wild rodents and shrews as natural sources of human infections in Northeast Portugal regarding the investigated parasites. Moreover, this is the first record of G. microti in southwestern water voles, Lusitanian pine voles, Algerian mice, wood mice and Cabrera's voles and C. muris in Cabrera's voles. Finally, this study improves the database of sequences relevant for the sequence typing of G. microti strains and provides new insights about the epidemiology of Giardia spp. and Cryptosporidium spp. in wild rodents and shrews, two parasite genera of high importance for public and animal health.

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.

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.

Multilocus genotyping of Giardia duodenalis in pre-weaned calves with diarrhea in the Republic of Korea

Giardia duodenalis is a protozoan parasite that infects humans, companion animals, livestock, and wildlife. Infections in cattle caused by this parasite are often asymptomatic, but such infections can cause diarrhea, reduced weight gain, and ill-thrift in young calves. Although G. duodenalis causes diarrhea in calves, only a few studies have been conducted on calves in the Republic of Korea (ROK). Here, we aimed to determine the prevalence and distribution of G. duodenalis assemblages in pre-weaned calves with diarrhea in the ROK, identify the association between the occurrence of G. duodenalis and the age of calf, and perform molecular characterization of G. duodenalis. We collected 455 fecal samples from pre-weaned native Korean calves (≤60 days old) with diarrhea in four different regions. G. duodenalis was detected using nested PCR targeting the beta-giardin (bg) gene, and positive samples were further genotyped for the glutamate dehydrogenase (gdh) and triosephosphate isomerase (tpi) genes. The overall prevalence of G. duodenalis in calves with diarrhea was 4.4% (20/455) based on the analysis of bg. The highest prevalence was observed in calves aged 11-30 days (7.5%; 95% confidence interval: 3.7%-11.3%), whereas the lowest prevalence was observed in neonatal calves. From the 20 samples that were positive for bg, 16, 5, and 6 sequences were obtained following genotyping of bg, gdh, and tpi, respectively. Sequencing analysis of the bg gene revealed the presence of assemblage E (n = 15) and sub-assemblage AⅠ (n = 1) in the samples. Moreover, we detected mixed infections with assemblages E and A in two calves for the first time. Among the sequences obtained herein, two new subtypes of assemblage E were detected in gdh and tpi sequences each. The results suggest that G. duodenalis is an infectious agent causing diarrhea in calves, and pre-weaned calves are at a higher risk of infection than neonatal calves. Multilocus genotyping should be performed to confirm the presence of potentially zoonotic genotypes. These results highlight the importance of cattle as a source of zoonotic transmission of G. duodenalis to humans.

Multigene typing of Giardia Duodenalis isolated from tuberculosis and non-tuberculosis subjects

Giardia duodenalis is a cryptic protozoan, which has eight assemblages (A-H). Assemblages A and B are the main genotypes reported from humans with probable anthroponotic and zoonotic transmission. The current study aimed to characterize G. duodenalis assemblages in tuberculosis (TB) patients and healthy subjects using multilocus genotyping (MLG). Thirty Giardia-positive stool samples, which were obtained from TB patients and healthy subjects were included in the study. After total DNA extraction, three β-giardin (bg), triosephosphate isomerase (tpi), glutamate dehydrogenase (gdh) genes were amplified and sequenced. Obtained sequences were compared to the GenBank database to characterize assemblages. Phylogenetic analysis using Maximum Likelihood (ML) and Tamura 3-parameter was performed for each gene. From 30 Giardia-positive subjects, 17 (57%) and 13 (43%) were from healthy and TB-infected subjects, respectively. There was no significant co-existence of Giardia and tuberculosis (P-value = 0.051). In addition, 14 (46.7%) and 16 (53.3%) of Giardia isolates were from asymptomatic and symptomatic subjects, respectively. PCR amplification was successful in 25 single samples (83.3%) consisted of 20 for tpi, 15 for bg, and 13 for gdh genes. Accordingly, 13/25 (52%) and 8/25 (32%) belonged to assemblage A and assemblages B, respectively, whereas 4/25 (16%) were either assemblage A or B with different genes at the same time. Significant correlation between assemblages and TB, age, and symptoms was not seen. The phylogenetic analyses represented no separation based on TB and gastrointestinal symptoms. Assemblage A was the predominant genotype in samples. The high frequency of assemblage AII indicated importance of anthroponotic transmission of Giardia in both healthy and TB patients. In addition, considering the exclusive reports of sub-assemblage AIII in wild ruminants, the presence of AIII in the current study have to be carefully interpreted. The inconsistency between the assemblage results of either bg or gdh loci with tpi gene signifies the insufficiency of single gene analysis and the necessity for MLG in molecular epidemiology of G. duodenalis.

Exploration of aminoacyl-tRNA synthetases from eukaryotic parasites for drug development

Parasitic diseases result in considerable human morbidity and mortality. The continuous emergence and spread of new drug-resistant parasite strains is an obstacle to controlling and eliminating many parasitic diseases. Aminoacyl-tRNA synthetases (aaRSs) are ubiquitous enzymes essential for protein synthesis. The design and development of diverse small molecule, drug-like inhibitors against parasite-encoded and expressed aaRSs have validated this enzyme family as druggable. In this work, we have compiled the progress to date towards establishing the druggability of aaRSs in terms of their biochemical characterization, validation as targets, inhibitor development, and structural interpretation from parasites responsible for malaria (Plasmodium), lymphatic filariasis (Brugia,Wuchereria bancrofti), giardiasis (Giardia), toxoplasmosis (Toxoplasma gondii), leishmaniasis (Leishmania), cryptosporidiosis (Cryptosporidium), and trypanosomiasis (Trypanosoma). This work thus provides a robust framework for the systematic dissection of aaRSs from these pathogens and will facilitate the cross-usage of potential inhibitors to jump-start anti-parasite drug development.

Retrospective Survey of Dog and Cat Endoparasites in Ireland: Antigen Detection

Endoparasites of dogs and cats, play an important role in both veterinary medicine and public health. Untreated and stray dogs and cats, in particular, play an important role in contaminating the environment with important zoonotic parasites. Thus, the aim of this study was to estimate the prevalence of intestinal parasites in stray dogs and cats using highly sensitive and specific copro-antigen tests. Archive faecal samples from previous surveys conducted between 2016−2019 from dogs (n = 789) and cats (n = 241) were included in this study. The IDEXX Fecal Dx™ antigen panel was used for the detection of Toxocara, hookworms, Trichuris and the SNAP™ Giardia antigen assay was used for the detection of Giardia infection. Giardia duodenalis was the most common parasite (26%, n = 205) detected in the dogs, followed by ascarids (17.6%, n = 139) and hookworms (5.3%, n = 42). Trichuris vulpis was only detected in 1 dog. Ascarids (23.2%, n = 56) was the most common parasite detected in the cats, followed by Giardia (12.9%, n = 31) and hookworms (n = 7, 2.9%). No whipworms were detected in cats. Overall, there was little difference in the positivity between sexes in both dogs and cats. However, in terms of age, adolescent dogs (<3 years) and kittens (<1 year) had the highest parasite prevalence overall, with G. duodenalis and ascarids being the most prevalent. This study shows a high prevalence of parasite infection in untreated and stray dogs and cats in the greater Dublin area in Ireland. Since they live in synanthropic conditions and can roam over vast distances they can contaminate public areas and pose a risk to both humans and owned pets that utilise these spaces. It is therefore important to raise public awareness and increase the knowledge on zoonotic parasites.

Extensive testing of a multi-locus sequence typing scheme for Giardia duodenalis assemblage A confirms its good discriminatory power

BACKGROUND

The flagellated parasite Giardia duodenalis is a major and global cause of diarrhoeal disease. Eight genetically very distinct groups, known as assemblages A to H, have been recognized in the G. duodenalis species complex, two of which (assemblages A and B) infect humans and other mammalian hosts. Informative typing schemes are essential to understand transmission pathways, characterize outbreaks and trace zoonotic transmission. In this study, we evaluated a published multi-locus sequence typing (MLST) scheme for G. duodenalis assemblage A, which is based on six polymorphic markers.

METHODS

We genotyped 60 human-derived and 11 animal-derived G. duodenalis isolates collected in Europe and on other continents based on the published protocol. After retrieving previously published genotyping data and excluding isolates whose sequences showed allelic sequence heterozygosity, we analysed a dataset comprising 146 isolates.

RESULTS

We identified novel variants at five of the six markers and identified 78 distinct MLST types in the overall dataset. Phylogenetic interpretation of typing data confirmed that sub-assemblage AII only comprises human-derived isolates, whereas sub-assemblage AI comprises all animal-derived isolates and a few human-derived isolates, suggesting limited zoonotic transmission. Within sub-assemblage AII, isolates from two outbreaks, which occurred in Sweden and Italy, respectively, had unique and distinct MLST types. Population genetic analysis showed a lack of clustering by geographical origin of the isolates.

CONCLUSION

The MLST scheme evaluated provides sufficient discriminatory power for epidemiological studies of G. duodenalis assemblage A.

Is there any change in the prevalence of intestinal or cardiopulmonary parasite infections in companion animals (dogs and cats) in Germany between 2004-2006 and 2015-2017? An assessment of the impact of the first ESCCAP guidelines

Main objective of the present nationwide study was to assess the impact of the ESCCAP guideline for the control of worm infections in dogs and cats 8-10 years after its first publication in Germany. A secondary aim was to determine the prevalence of canine and feline cardiopulmonary nematodes and intestinal protozoa. Faecal samples of 53,693 dogs and 26,491 cats in 2004-2006 as well as of 129,578 dogs and 45,709 cats in 2015-2017 routinely submitted by veterinarians to a private veterinary laboratory were examined using appropriate parasitological methods. In dogs, the prevalence of Toxocara and taeniid egg shedding was significantly lower in 2015-2017 (3.8 % and 0.16 %, respectively) than in 2004-2006 (4.6 % and 0.27 %, respectively). The prevalence of hookworm and Capillaria eggs was higher in the second study period (2.3 % and 0.77 %, respectively) than in the first (1.3 % and 0.6 %, respectively). For Toxascaris leonina (0.55-0.6 %) and Trichuris (0.8-0.9 %), the difference was not significant between the study periods. Dogs shed more often Angiostrongylus vasorum larvae in the second study (3.1 %) than in the first (1.0 %), whereas the prevalence of Crenosoma vulpis did not change significantly (2.2-2.6 %). Cystoisospora canis and C. ohioensis-like infections were less detected in the second study period (1.0 % and 2.1 %, respectively) than in the first (1.8 % and 2.7 %, respectively). Neospora-like oocysts and Sarcocystis sporocysts were more prevalent in the second study period (0.19 % and 0.13 %, respectively) than in the first (0.13 % and 0.06 %, respectively). The percentage of Giardia or Cryptosporidium coproantigen-positive samples was lower in the second study period (18.9 % and 6.7 %, respectively) than in the first (22.8 % and 10.0 %, respectively). In cats, the prevalence of egg shedding of T. cati, Capillaria and taeniids was significantly lower in 2015-2017 (3.5 %, 0.25 % and 0.1 %, respectively) than in 2004-2006 (4.8 %, 0.54 % and 0.22 %, respectively). No difference was recorded for hookworms (0.12-0.13 %) and Ts. leonina (0.04-0.05 %). Aelurostrongylus-like larvae were detected more often in the second study period (6.5 %) than in the first (2.6 %). Infections with Cystoisospora felis, C. rivolta, Toxoplasma-like coccids and Sarcocystis were less prevalent in the second study period (1.9 %, 0.7 %, 0.24 % and 0.02 %, respectively) than in the first (2.7 %, 1.1 %, 0.36 % and 0.1 %, respectively). The percentage of Giardia or Cryptosporidium coproantigen-positive samples was significantly lower in the second study period (10.6 % and 4.8 %, respectively) than in the first (15.4 % and 8.3 %, respectively). Although these results indicate a decline of the occurrence of most canine and feline intestinal parasites in Germany over the years, a transmission risk of zoonotic parasites remains. Therefore, the control of helminth infections in domestic dogs and cats continues to be a challenge for veterinarians and pet owners.

Vector-borne and other pathogens of potential relevance disseminated by relocated cats

Large populations of unowned cats constitute an animal welfare, ecological, societal and public health issue worldwide. Their relocation and homing are currently carried out in many parts of the world with the intention of relieving suffering and social problems, while contributing to ethical and humane population control in these cat populations. An understanding of an individual cat’s lifestyle and disease status by veterinary team professionals and those working with cat charities can help to prevent severe cat stress and the spread of feline pathogens, especially vector-borne pathogens, which can be overlooked in cats. In this article, we discuss the issue of relocation and homing of unowned cats from a global perspective. We also review zoonotic and non-zoonotic infectious agents of cats and give a list of practical recommendations for veterinary team professionals dealing with homing cats. Finally, we present a consensus statement consolidated at the 15th Symposium of the Companion Vector-Borne Diseases (CVBD) World Forum in 2020, ultimately to help veterinary team professionals understand the problem and the role they have in helping to prevent and manage vector-borne and other pathogens in relocated cats.

Graphical Abstract

Multilocus sequence typing of Giardia duodenalis genotypes circulating in humans in a major metropolitan area

Giardia duodenalis is an intestinal protozoan parasite of humans and animal hosts and comprises eight microscopically indistinguishable molecularly-diverse lineages designated as assemblages A-H. Assemblages A and B are the primary sources of infections in humans and a wide range of mammals. Here, we identified assemblages, and inter-/intra-assemblage genetic diversity of human G. duodenalis isolates based on the multilocus sequence typing of the triosephosphate isomerase (tpi), β -giardin (bg), and glutamate dehydrogenase (gdh) loci. Multilocus sequence analysis of 62 microscopically-positive G. duodenalis fecal samples identified 26 (41.9%), 27 (43.5%), and nine (14.5%) isolates belonging to assemblages A, B, and discordant assemblages, respectively. The tpi locus assemblage-specific primers identified dual infections with A and B assemblages (45.2%). The sequence analysis of multiple alignments and phylogenetic analysis showed low genetic polymorphism in assemblage A isolates, classified as sub-assemblage AII at three loci, subtype A2 at tpi and gdh loci, and subtype A2 or A3 at bg locus. High genetic variations were found in assemblage B isolates with 14, 15, and 23 nucleotide patterns at tpi, bg, and gdh loci, respectively. Further concatenated sequence analysis revealed four multilocus genotypes (MLG) in 24 assemblages A isolates, two previously-identified (AII-1 and AII-5), with one novel multilocus genotype. However, the high genetic variations observed in assemblage B isolates among and within the three genetic loci prevented the definitive designation of specific MLGs for these isolates. Multilocus sequence typing may provide new insight into the genetic diversity of G. duodenalis isolates in Tehran, suggesting that humans are likely a potential source of G. duodenalis infection. Further host-specific experimental transmission studies are warranted to elucidate the modes of transmission within multiple host populations.

Detection of Giardia duodenalis and Toxoplasma gondii in soil and water samples in the Quindío River basin, Colombia

Two zoonotic protozoan pathogens, Giardia duodenalis and Toxoplasma gondii, are important causes of waterborne infections in the Quindío region in Colombia. No previous data exist on how contamination occurs at the source for drinking water consumed by the human population in this region. Our aim was to describe the frequency of G. duodenalis and T. gondii DNA in 11 sampling points during a five-month period in water and adjacent soil at the Quindío River basin (Andean region in the central western part of Colombia). The study employed nested PCR for T. gondii, using the B1 gene as the amplification target, and single-round PCR for G. duodenalis assemblage A and assemblage B, amplifying the gdh gene, followed by DNA sequencing. In 50 soil samples, 28% (14/50) were positive for T. gondii. For G. duodenalis, distribution was in equal parts for assemblage A (8%; 4/50) and assemblage B (8%, 4/50). Genotyping of T. gondii sequences showed two soil samples with type I strain, another two samples of soil with type III strain, but most samples were of unidentified strains. In water samples, T. gondii was detected in 9.1% (5/55), G. duodenalis assemblage A in 34.5% (19/55), and G. duodenalis assemblage B in 12.7% (7/55). T. gondii DNA positivity was associated with lower soil temperature (p = 0.0239). Presence of G. duodenalis and T. gondii was evidenced in soil and water samples in the Quindío River basin, indicating soil as the potential source of contamination for the river that it is destined for human consumption. Monitoring these protozoa in drinking water is necessary to prevent public health risks in human populations.

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55 water and 50 soil samples from Colombian Quindio river basin were studied.

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Positive soil: 28% T. gondii, 8% G. intestinalis assemblages A and B.

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Positive water: 9.1% T. gondii, 4.5% G. intestinalis assemblages A and B.

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Soil and water are potential sources of contamination for river water that is destined for human consumption.

Zoonotic Giardia duodenalis Genotypes and Other Gastrointestinal Parasites in a Badger Population Living in an Anthropized Area of Central Italy

The Eurasian badger (Meles meles) is widespread in Italy and occupies different habitats. The occurrence and species of gastrointestinal parasites were evaluated in a free-ranging badger population living in a highly anthropic area in central Italy. A total of 43 fecal samples were examined using the flotation test, the Mini-FLOTAC and Baermann techniques, and a rapid immunoassay for the detection of Giardia duodenalis and Cryptosporidium spp. fecal antigens. Molecular investigations were also performed that aimed at identifying Giardia genotypes. Overall, 37/43 samples (86%) were found positive. Specifically, 48.8% (21 samples) were positive for G.duodenalis, 23.2% (10/43) for Cryptosporidium spp., and 7% (3/43) for coccidian oocysts. Strongyloides sp. nematode larvae were detected in 3/43 samples (7%). Ascarid (1/43, 2.3%), capillariid (1/43, 2.3%), and strongyle-type eggs (76.7%, 33/43) were also identified. Among the 11 readable sequences of samples that were positive for G. duodenalis by end-point PCR (18/21), the zoonotic assemblage A sub-assemblage AII and mixed assemblage A and B were identified. This is the first report of zoonotic G. duodenalis genotypes in the Eurasian badger. Moreover, most of identified parasites have zoonotic potential and/or potential impact on the population health of wild badgers and other wild and domestic animals.