Transmission and epidemiology of zoonotic protozoal diseases of companion animals

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

BACKGROUND

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

METHODOLOGY

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

PRINCIPAL FINDINGS

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

CONCLUSIONS/SIGNIFICANCE

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

Epidemiology, molecular characterization, and risk factors of Acanthamoeba spp., Blastocystis spp., and Cyclospora spp. infections in snakes in China

Snakes are widely farmed in China for medicinal purposes and as pets worldwide. Acanthamoeba spp., Blastocystis spp., and Cyclospora spp. are significant zoonotic pathogens frequently discovered in various animals, causing diseases with global public health implications. However, their prevalence and zoonotic potential in snakes remain poorly understood. In this study, 812 snake faecal samples were collected across 28 China provinces. The partial small subunit (SSU) rRNA gene was amplified using polymerase chain reaction (PCR) to assess evolutionary relationships and genetic characterization. Detection rates for Acanthamoeba spp., Blastocystis spp., and Cyclospora spp. were 6.40 %, 3.33 %, and 2.71 %, respectively. Sequencing and phylogenetic analysis revealed that Cyclospora isolates were closely related to those found in humans and cattle. Subtyping for Blastocystis species identified two zoonotic subtypes (ST4, ST6) and four host-specific subtypes (ST10, ST15, ST21, ST42). Multiple Acanthamoeba genotypes were detected, including T4, T11, and T13. Furthermore, species, age, and living conditions are key risk factors. This study provides valuable insights into these infections in snakes and underscores the need for proper hygiene and One Health measures to reduce zoonotic transmission and environmental contamination.

Impact of Temperature Variations on the Viability and Infectivity of Sporulated Eimeria papillata Oocysts in C57BL/6 Mice

Eimeria is a protozoan apicomplexan parasite that affects animals and poultries. This study investigated how temperature variations impact the inactivation of sporulated E. papillata oocysts during experimental infections in mice. A total of 20 male C57BL/6 mice were divided into four groups, with five mice in each group, as follows: Group 1: Control group - Group 2: Infected group inoculated with fresh oocysts (subjected to 23 ℃ for 7 days) - Group 3: Infected group inoculated with thermal oocysts (subjected to heating conditions at 100 ℃ for 60 min) - Group 4: Infected group inoculated with frozen oocysts (subjected to freezing at -20 ℃ for 7 days). An oral infection was initiated using 103 sporulated E. papillata oocysts to inoculate groups 2-4. Biological indicators, including body weight (BW) and feed intake (FI), were evaluated for each group. Oocyst output was assessed on day 5 post-infection. After sacrificing the mice, jejunal tissues were collected and processed for histopathological and biochemical analyses. Our findings indicated significant morphological alterations of sporulated Eimeria oocysts (i.e. a reduction in oocyst size and rounded shape of sporozoite) after being subjected to heating and freezing conditions. During the in vivo study, temperature treatment data shows significant inactivation of oocysts, with no fecal shedding. This result reflects enhancements in biological indicators and histopathological injuries, with the absence of intracellular Eimeria stages in the jejunal tissues, alongside a restoration of nutrient composition, particularly carbohydrates and proteins. Significant observations were also recorded regarding catalase (CAT), glutathione (GSH), nitric oxide (NO), and hydrogen peroxide (H2O2) levels. Temperature changes impact the viability of Eimeria oocysts and their role in coccidiosis. More research is needed on other biotic and abiotic factors in managing the disease.

Fighting Strategies Against Chagas' Disease: A Review

Chagas disease, caused by Trypanosoma cruzi, remains a significant public health challenge, particularly in Latin America, where it is one of the most neglected diseases and is primarily transmitted by triatomine insects. The disease exhibits complexity due to its diverse transmission routes, including vectorial and non-vectorial mechanisms such as blood transfusions and congenital transmission. Effective monitoring and control strategies are critical to mitigating its impact. This review focuses on current monitoring and control efforts, emphasizing the importance of enhanced surveillance systems, improved risk assessments, and integrated vector control programs. Surveillance plays a pivotal role in early detection and timely intervention, particularly in endemic regions, while vector control remains central to reducing transmission. Moreover, the development of novel diagnostic tools, treatments, and vaccines is a crucial step in advancing control efforts. This review also highlights the involvement of local governments, international organizations, and civil society in executing these strategies, stressing the need for sustained political commitment to ensure the success of public health programs. By addressing key challenges in monitoring, control, and prevention, this review aims to provide insights and recommendations to further global efforts in reducing the burden of Chagas disease.

Global Prevalence and Subtype Distribution of Blastocystis sp. in Rodent Populations: A Systematic Review and Meta-Analysis

BACKGROUND

The present systematic review and meta-analysis aimed to gather and analyse global data on the prevalence, subtypes (STs) distribution and zoonotic potential of Blastocystis sp. in rodents.

METHODS

A systematic literature search was performed across multiple databases (PubMed, Scopus, Web of Science and ProQuest) for studies published by 23 July 2024. The analysis included 34 studies/78 datasets, comprising 5661 samples from various rodent species across 15 countries. Statistical analyses were performed using comprehensive meta-analysis (CMA) software, employing a random-effects model to estimate pooled prevalence and 95% confidence intervals (CIs) and the I2 index for assessing heterogeneity.

RESULTS

This review found that 16% (95% CI: 12.6%-20.2%) of rodents worldwide were infected with Blastocystis sp. Voles and squirrels exhibited the highest infection rates at 29.8% (95% CI: 14.7%-51%) and 28.8% (95% CI: 14.4%-49.2%), whereas civets and porcupines had the lowest rates at 9.5% (95% CI: 6.6%-13.6%) and 7.1% (95% CI: 3.3%-14.7%), respectively. The findings indicated that rodents can host various Blastocystis sp. STs (ST1-ST8, ST10, ST13, ST15, ST17), with several (ST1-ST8 and ST10) having zoonotic potential. Globally, ST4, ST5, ST1 and ST3 were the most commonly reported STs in rodents. China and the UK showed the highest ST diversity in rodents, with 10 (ST1-ST7, ST10, ST13, ST17) and 7 (ST1-ST5, ST10, ST15) distinct STs, respectively. ST6, ST7 and ST13 were unique to China, whereas ST15 was found only in the United Kingdom. Squirrels, rats, mice and voles had the highest ST diversity of Blastocystis sp., with 8, 7, 5 and 5 distinct STs, respectively. Notably, ST6 and ST13 were unique to squirrels, ST7 only appeared in rats, and ST15 was found only in voles. Most ST1, ST3-ST5 and ST17 came from Asia. ST6, ST7 and ST13 were also isolated there, whereas ST15 was only found in Europe. ST17 was reported in Africa, ST4 and ST17 in North America, and ST1-ST3 and ST8 in South America.

CONCLUSIONS

This review emphasizes the widespread presence of Blastocystis sp. in rodent populations globally, underscoring the need for continued surveillance and research into its zoonotic potential.

Operational Risk Assessment Tool for Evaluating Leishmania infantum Introduction and Establishment in the United States through Dog Importation1

International pet travel and commercial operations have increased animal disease importation risks, including for Leishmania infantum, a deadly parasite of humans and domestic dogs. Collaborating as an interdisciplinary working group, we developed an operational tool for veterinary and public health practitioners to assess and manage L. infantum risk in dogs imported to the United States. Overall risk varies by dog, human, and geographic factors but could be high without proper controls. We determined dog risk management strategies should include application of sand fly insecticides and repellents, sterilization, and treatment. US public health authorities can use a One Health approach to manage L. infantum importation risks via infected dogs.

Clinical anemia predicts dermal parasitism and reservoir infectiousness during progressive visceral leishmaniosis

Dogs represent the primary reservoir for Leishmania infantum human visceral leishmaniasis (VL) transmitted through phlebotomine sand flies. Public health initiatives targeting zoonotic VL commonly focus on dogs with severe clinical disease, often in renal failure, as they have previously been considered the most infectious to sand flies. However, more recent studies suggest that dogs with mild to moderate clinical disease may be more infectious than dogs with severe disease. The mechanisms of infectiousness from the skin and how this relates to transmissibility as clinical disease progresses is largely unknown. We evaluated dermal parasitism in dogs naturally infected with L. infantum across the four LeishVet clinical stages of disease. We establish the relationship between dermal parasitism, critical, frequently observed, clinical parameters such as anemia and creatinine, and infectiousness. Using RNAscope and confocal microscopy, we found notable variation in dermal parasitism between dogs, particularly within LeishVet II. Dogs with mild disease had significantly less dermal inflammation and parasitism than dogs with moderate or severe disease. We found significant correlations between anemia, dermal parasitism, and infectiousness (p = 0.0098, r = -0.4798; p = 0.0022, r = -0.8364). In contrast, we did not observe significant correlation between creatinine, a measure of renal function, and dermal parasitism or infectiousness. Host blood cell abnormalities, including anemia, correlate with infectiousness to sand flies. As these signs of disease often appear earlier in the course of disease, this indicates that classical measures of disease severity do not necessarily correlate with infectiousness or epidemiological importance. Public health initiatives attempting to break the zoonotic cycle of L. infantum infection should therefore focus on preventing transmission from infectious, anemic dogs, and not those with the most severe disease.

Molecular detection of potentially zoonotic protozoa in the Chandigarh region, India

CONTEXT

The contamination of soil by pathogenic protozoan parasites from both human and animal feces, is an important factor in the spread of parasitic infections globally. This contamination also serves as a crucial reservoir for zoonotic diseases, facilitating their transmission. In many developing nations, including India, there's limited documentation on the extent of soil contamination, which poses challenges for implementing effective One Health strategies aimed at controlling these infections.

AIM

To study the molecular prevalence and distribution pattern of pathogenic protozoa in soil from North India.

METHODS

In this prospective cross-sectional study, we collected a total of 200 soil samples from various locations in the Chandigarh region, including public parks, urban slum areas, villages on the outskirts, and sites near cattle sheds, hospitals, and public school. DNA extraction was done in all the samples followed by conventional and nested PCR for the identification of Toxoplasma gondii, Entamoeba histolytica, Giardia duodenalis, and Cryptosporidium species from these samples.

KEY RESULTS

Out of 200, 34 soil samples (17 %) from different sites in Chandigarh were found to have pathogenic protozoan contamination. Toxoplasma gondii was the most common protozoa (n = 18), followed by Entamoeba, Giardia, and Cryptosporidium species. Urban slums and public parks were most likely to be contaminated with oocysts/ cyst of pathogenic protozoa.

CONCLUSIONS

This study is the first of its kind in India and the prevalence of oocyst /cyst of protozoa in our city was found significant. The findings underscore the critical role of soil contamination by pathogenic protozoa as a potential source for spreading zoonotic infections.

Holothuria polii Extract as a Potential Anticoccidial Agent: Evidence of Its MUC2 Regulatory Impact in Murine Jejunum

Eimeria is a parasite that causes coccidiosis in a variety of animals, leading to nutritional imbalances, issues with food digestion and absorption, low weight, and intestinal inflammation of varying degrees in its hosts. Anticoccidial medication resistance has become a significant obstacle to disease control efforts, leading to a renewed focus on discovering novel chemicals for alternative therapeutic approaches. The purpose of this study was to determine the efficacy of Holothuria polii extract (HpE) in treating eimeriosis in mice. Five groups of mice were studied, with E. papillata sporulated oocysts (1 × 103) used to infect three groups experimentally. The first group was treated with 200 mg/kg of HpE, the second group with Amprolium (120 mg/kg), and the third group was left untreated as a control. The fourth and fifth groups were uninfected, with one of them treated with 200 mg/kg of HpE and the other used as a negative control. The results revealed that HpE has 10 phytochemical compounds according to GC-MS analysis. Treatment with HpE resulted in a substantial decrease in oocyst output in feces. Also, the parasitic stages showed morphometric alterations, with reductions in the measurements compared with the infected, untreated mice. Moreover, expression of the mucin gene (MUC2) was higher in treated mice compared to infected ones, with significant increases in goblet cell numbers, which provided additional evidence for the activity of HpE as an anticoccidial product. In conclusion, there are a wide variety of natural products and many have been employed in folk medicine for treating a range of parasitic diseases.

Gastrointestinal parasites of cats in the Middle East (2000-2023): A literature review

BACKGROUND/OBJECTIVE

Gastrointestinal parasites in stray cats are of significant clinical and zoonotic importance and pose a potential threat to public health. Hence, the current review has practical implications as it aims to present the diversity and the prevalence of cat parasites in Middle Eastern countries.

METHODS

The research process was rigorous and thorough, spanning from 2000 to 2023. Data collection and analysis were conducted utilizing multiple international and national databases, including Google Scholar, Scopus, PubMed, and Irandoc. This meticulous approach ensures the reliability and validity of the findings, providing a solid foundation for further research and preventive measures.

RESULTS

A total of 159 articles were collected and comprehensively reviewed. Among these, 85 articles were from Iran, 25 from Türkiye, 20 from Iraq, 11 from Egypt, five from Qatar, three from Cyprus, three from Kuwait, and one each from the UAE, Saudi Arabia, Syria, Lebanon, Jordan, Israel, and Palestine. Toxocara cati was the most prevalent nematode, exhibiting the highest prevalence in Iran, ranging from 8% to 90%, followed by Egypt, with a range of 8.23% to 58.7%. In comparison, the lowest prevalence was recorded in Qatar at 8%. Hydatigera taeniaeformis, a common cestode in the feline, showed the highest prevalence in Qatar, with a range of 73.6% to 75.8%, while the lowest was in Kuwait at 0.8%. In Iran, the prevalence ranged from 0.9% to 64.7%. Toxoplasma gondii, a cosmopolitan protozoan, showcased the highest prevalence in Lebanon at 78.1% and the lowest in the UAE at 0.8%. In Iran, the prevalence ranged between 1.2% and 90%. Additionally, noteworthy patterns regarding the distribution and potential risk factors associated with these parasites were observed. While gender variations were not significant, environmental conditions such as high humidity and absence of sunlight exposure, along with the age and behavior of cats, were among the risk factors associated with the prevalence of parasites.

CONCLUSION

The prevalence of parasites among stray cats in Iran and other Middle Eastern countries remains notably high. This emphasizes the urgent need for a series of control and preventive measures. Implementing effective anti-parasitic strategies and emphasizing the development of multiple diagnostic methods are essential.

Development and preliminary study of the rLiNTPDase2 rapid test: A lateral flow immunochromatographic assay for Canine Visceral Leishmaniasis

Canine Visceral Leishmaniasis (CVL) is the most fatal form of Leishmania infection in dogs and is caused by L. infantum in the Americas. This parasite follows a zoonotic life cycle, raising concerns within domestic households, where dogs act as the primary reservoir of the parasite. Accurately detecting infected dogs is vital for effective epidemiological control in both canine and human populations. However, existing diagnostic methods in Brazil have limitations, particularly in detecting asymptomatic and oligosymptomatic dogs, leading to ineffective disease control. To address this challenge, we evaluated a novel recombinant antigen from L. infantum, the rLiNTPDase2. Previous studies have confirmed its high performance via ELISA, leading us to assess its suitability for a Lateral Flow Immunochromatographic Assay (LFIA), which is ideal for point-of-care testing. Standardization of the assay involved testing two nitrocellulose membranes (HF135 and HF120, Millipore), three blocking protocols, and five sample dilutions (1:10, 1:20, 1:40, 1:80, and 1:160). Following the chosen conditions (HF120 membrane, 1-minute blocking protocol, and 1:80 sample dilution), we validated our assay with a sample size of 78 dogs, comprising 32 negatives and 46 positives, including symptomatic (n=23), oligosymptomatic (n=17), and asymptomatic (n=6) cases. The results revealed a sensitivity of 86.9 %, specificity of 62.5 %, and accuracy of 76.9 %, which is consistent with ELISA performance for the same samples. Compared to DPP-LVC, our assay demonstrated promising results in detecting asymptomatic and oligosymptomatic cases. This study underscores the suitability of the rLiNTPDase2 antigen for the LFIA format, suggesting its potential as a novel point-of-care diagnostic test for CVL.

Parasites Diversity, Abundance, Prevalence, and Richness Infecting Didelphis aurita (Didelphimorphia: Didelphidae) in the Atlantic Rainforest, Brazil

Parasites are key players in ecosystems, influencing population sizes and food webs, yet the impact of environmental factors on their diversity is not well understood. The Atlantic rainforest in Brazil, particularly the Parque Estadual das Fontes do Ipiranga (PEFI), exemplifies a biodiversity hotspot facing significant deforestation, housing diverse animal species such as the synanthropic Brazilian common opossum (Didelphis aurita), which serves as a reservoir for multiple zoonotic pathogens. In this study, we investigated parasite diversity, abundance, prevalence, and richness in free-living D. aurita in the PEFI, São Paulo, Brazil. From January 2015 to January 2017, 101 fecal samples of D. aurita were collected in two areas of PEFI, at the Instituto de Pesquisas Ambientais (IPA) and the Parque de Ciência e Tecnologia (Cientec), and analyzed using three different parasitological methods. In total, 99% of the samples were positive for at least one parasite. The most prevalent parasite belonged to the order Strongylida (82%), followed by Cruzia sp. (77%), the latter having a significantly higher prevalence at IPA. In contrast, Acanthocephala showed greater prevalence at Cientec. Co-infections were common, with some individuals harboring up to seven different parasites. Our findings reveal significant parasite diversity in the D. aurita population at PEFI, including both helminths and protozoan trophozoites, some of which are reported for the first time in this host species. Further research is essential for accurate species identification of the observed parasites.

Epidemiology of cat bites to people in Uruguay: Effects of the age and sex of the victim, season of the year, and the COVID-19 pandemic

Background

Cat bites to people are an important public health problem. However, very little information exists on the epidemiology of people bitten by cats at the level of an entire country in Latin America. Additionally, the COVID-19 pandemic significantly influenced people's lives and their relationships with pets, which could potentially affect the frequency of people bitten by cats.

Aim

The aim of this study was to determine the prevalence of people bitten by cats in Uruguay (2010 to 2020) according to the sex and age of the victim, season of the year, and to compare the prevalence in the pandemic year (2020) with that of the pre-pandemic years (2010-2019).

Methods

Cross-sectional study. Cat-bite notifications for the 2010-2020 period were analyzed using data from the Uruguayan Ministry of Public Health (Uruguay).

Results

The annual cat-bite rate for the 2010-2020 period was 2.1 per 100,000 people. The frequency of cat bites varied with the victim´s sex (p < 0.0001), being greater in females (n = 506, 66.5%) than in males (n = 255, 33.5%). The age at being bitten by cats varied with the sex of the victim, with males being bitten at an earlier age than females (p < 0.0001). Among the age categories of 30-74 years, females were bitten more than males (p < 0.05). Overall, cat bites were much less frequent in the oldest age categories (over 75 years old, p < 0.05). The percentage of cat bites tended to change with the season of the year (p = 0.08), with most bites occurring in spring and summer. The frequency of cat-bite injuries was similar between 2020 and the pre-COVID-19 pandemic years.

Conclusion

In Uruguay, cat bite incidents were affected by the victim's sex (more in females) and age, as well as by the season. During the initial year of the COVID-19 pandemic, the rate of cat bites was no different from those in earlier years.

Unveiling food safety knowledge and practices among pet owners in Lebanon

Owning pets offers various potential health benefits; however, it can be associated with gastrointestinal illnesses due to poor food safety knowledge and practices. This study aimed to evaluate the level of food safety knowledge and practices among pet owners in Lebanon, exploring the association between their knowledge/practices and socio-demographic characteristics. The participants included 300 pet owners, representing various genders, ages, educational levels, educational backgrounds, and incomes. They completed a questionnaire of 72 food handling practices and knowledge questions related to preparation, cross-contamination, storage and hygiene. In parallel, 300 non-pet owners with comparable sociodemographic characteristics to pet owners (control group) completed the questionnaire. On average, food safety knowledge scores were 62.1 ± 14.9% and 58.7 ± 15.5% among pet and non-pet owners, respectively, and the difference was significant (p = 0.05). On the other hand, mean food safety practice scores were 41.3 ± 14.8% and 40.4 ± 15.3% among pet and non-pet owners, respectively, and the difference was not significant (p = 0.41). In the food safety knowledge part, non-pet owners who were young, high income, university graduate, and from health-related majors scored significantly (p < 0.05) higher, while among pet-owners, only participants with a university degree and from health-related majors scored significantly (p < 0.05) higher, in terms of knowledge. On the other hand, In the food safety practices part, non-pet owners who were young, high income, and university graduates scored significantly (p < 0.05) higher, while among pet-owners, only young and high-income participants scored significantly (p < 0.05) higher. These results highlight the need for ongoing educational initiatives to improve food safety practices among both pet owners in Lebanon. The study suggests that targeted educational programs should be developed, considering specific socio-demographic characteristics, to enhance overall food safety awareness and practices among the population.

The Influence of the Protozoan Giardia lamblia on the Modulation of the Immune System and Alterations in Host Glucose and Lipid Metabolism

Giardia lamblia, the cause of giardiasis, significantly impacts patients with metabolic disorders related to insulin resistance (IR). Both giardiasis and metabolic disorders share elements such as chronic inflammation and intestinal dysbiosis, which substantially affect the metabolic and cytokine profiles of patients. This review discusses the mechanisms of virulence of G. lamblia, its influence on the immune system, and its association with metabolic disorders. The review aims to show how G. lamblia invasion acts on the immune system and the glucose and lipid metabolism. Key findings reveal that G. lamblia infection, by disrupting intestinal permeability, alters microbiota composition and immune responses, potentially impairing metabolic status. Future research should focus on elucidating the specific mechanisms by which G. lamblia influences the metabolism, exploring the long-term consequences of chronic infection, and developing targeted therapeutic strategies that include both parasitic and metabolic aspects. These insights underscore the need for a multidisciplinary approach to the treatment of giardiasis in patients with metabolic disorders.

Zoonotic Parasites and Their Association With Human Activities in Northern Tanzania: An Integrated Ecosystem Approach for One Health

The community's awareness of the prevalence and impact of zoonotic diseases has been significantly underestimated, leading to insufficient implementation of control measures. This study was carried out in Northern Tanzania between 2019 and 2023 to investigate zoonotic parasites and the risks associated with human activities that contribute to zoonotic diseases. Cross-sectional surveys were conducted in 12 villages, including nine in Loliondo Division and three in Babati District. Focus Group Discussions and Key Informant Interviews were conducted to assess the community's knowledge and practices regarding the risks associated with zoonotic diseases in the surveyed areas. A total of 255 samples were collected from various sources, including latrines, households, livestock enclosures, domestic dogs, and chickens. Out of these samples, 152 tested positive for identifiable parasite eggs and oocysts. These parasites included hookworms (21.7%), Trichuris sp. (14.5%), Strongyloides sp. (13.8%), Eimeria sp. (19.7%), Taeniids (5.9%), Hymenolepis sp. (3.3%), Spirometra sp. (2.6%), and Dipylidium sp. (0.7%). Taeniids and Spirometra species were predominantly found in villages near protected areas such as Arash Sokoni, Oloipiri, Sukenya, Wasso, Orkuyiene, Haytemba, and Loliondo. Hookworms were most commonly detected in Arash Sokoni, Loliondo, Isuguro, and Hyatemba, while Strongyloides sp. was prevalent in Wasso, Sukenya, and Olobo villages. The quantitative analysis reveals significant associations between hygiene practices, proximity to livestock enclosures, ecological factors, and human-animal interaction, highlighting their pivotal roles in determining soil-transmitted helminth (STH) prevalence across different villages. This study reveals that there was a generally low level of awareness regarding zoonotic diseases and STHs. The detection of STH samples, combined with the limited understanding of zoonotic diseases, emphasizes the importance of taking proactive measures to reduce transmission risks. Prioritizing education and promoting awareness along with implementing comprehensive strategies are essential steps to effectively tackle the problems linked to STH infections and substantially lessen the public health burden caused by zoonotic diseases.

Fighting eimeriosis by using the anti-eimerial and anti-apoptotic properties of rhatany root extract

Background

Over the last decade, extensive use of coccidiostats to treat and control Eimeria infection has developed drug resistance, prompting the search for new alternative therapies. Rhatany is proven to have various pharmacological properties.

Objective

The present study aimed to in vitro and in vivo evaluate the effect of Rhatany roots extract (RRE) as an anti-eimerial and anti-apoptotic agent against murine eimeriosis induced by Eimeria papillata.

Methods

Phytochemical screening by gas chromatography-mass spectrometry analysis (GC-MS) was used to detect active compounds in RRE. In vitro anti-eimerial activity of RRE (200, 100, 50 mg/ml), amprolium, phenol, Dettol™, and formalin were studied after incubation with non-sporulated Eimeria oocysts. For the in vivo study, twenty-five male C57BL/6 mice were randomly allocated into five groups. Animals in the first group were just given distilled H2O, while those in the second group were given 200 mg/kg RRE for 5 days. The Eimeria parasite's oocysts were infected into the third, fourth, and fifth groups. For treatment, RRE (200 mg/kg) and amprolium (120 mg/kg) were orally given to the 4th and 5th groups for five days, respectively. All mice were euthanized, on day 5 post-infection, to collect the jejunal tissues under study. Investigations were undertaken into the oocyst output in feces and goblet cells in mice jejuna. Assays for glutathione peroxidase (GPx), hydrogen peroxide (H2O2), and myeloperoxidase (MPO) were also performed. In jejunal tissue, cysteine aspartic acid protease-3 (Caspase-3) was counted using immunohistochemistry, while BCL2-associated X protein (Bax) and B-cell lymphoma-2 (BCL-2) were assayed using ELISA. In addition, mRNA expression of the goblet cell response gene (MUC2) was detected using real-time PCR.

Results

Phytochemical screening by GC-MS demonstrated the presence of 22 compounds in the RRE. The in vitro study revealed that RRE significantly inhabited the oocyst sporulation in a dose-dependent manner. By day 5 after infection with the Eimeria parasite, the number of oocysts in mice feces was significantly reduced after RRE treatment (1.308 × 106 ± 1.36 × 105 oocysts/g feces) compared to the infected group (5.387 × 106 ± 4.29 × 105 oocysts/g feces). Moreover, the Eimeria infection reduced the number of goblet cells of mice jejuna and its specific gene, MUC2. The treatment with RRE increased the number of goblet cells/villus from 3.45 ± 0.17 to 6.04 ± 0.23, associated with upregulation for MUC2 from 0.26 to 2.39-fold. Also, the Eimeria experimental infection lowered the activity of the antioxidant enzyme represented by GPx (23.99 ± 3.68 mg/g tissue), while increasing the stress parameters of hydrogen peroxide (0.07 ± 0.01 mM/g) as well as the activity of MPO (66.30 ± 3.74 U/mg). The production of apoptotic markers including Caspase-3 (68.89 ± 2.67 U/g) and Bax (159.05 ± 6.50 pg/ml) was significantly elevated while decreasing the anti-apoptotic marker of BCL2 (0.42 ± 0.07 pg/ml). Our study proved that RRE significantly reduced oxidative stress, and apoptotic markers as well as the inflammatory activity of MPO. Also, antioxidant enzyme and anti-apoptotic activity in the jejunum of E. papillata-infected mice were enhanced after RRE treatment.

Conclusion

Our study highlights the potential of RRE as a natural solution for coccidiosis management by modulating apoptosis in E. papillata host cells. However, further research is needed to fully understand the underlying mechanisms and enhance our understanding of its therapeutic efficacy.

Comparative performance evaluation of four different methods for diagnosing Giardia infection in dogs and zoonotic assemblages' identification

Giardia duodenalis (syn. G. intestinalis or G. lamblia) is a parasitic protozoan that infects the upper intestinal tract of a broad range of hosts, including humans and domestic animals. Thus, it has raised concerns about the public health risk due to companion animals. Recently, with the improvement of living standards and increasing contacts between pets and humans, the zoonotic transmission of Giardia has dramatically increased. From a genetic point of view, G. duodenalis should be viewed as a complex species that includes eight different species-specific genetic assemblages. The laboratory diagnosis is mainly based on the finding of microscopic cysts in stool samples by coprological examination. Other methods include the detection of antigens, immunoassays or PCR protocols, which allow the identification of Giardia assemblages. The study aimed to compare the performance of Direct Fluorescence Antibody test (DFA), zinc sulfate flotation technique (ZnSO4), rapid diagnostic test (RDT), end-point PCR amplification (PCR) for the detection of Giardia and to identify the concerning assemblages in a canine population from Central Italy. Direct fluorescence antibody test is the reference standard for laboratory diagnosis of Giardia in fecal samples from dogs, despite the microscopic examination after flotation remains the most useful method in many veterinary diagnostic centers. The present findings demonstrate the high performance of DFA and ZnSO4 in detecting Giardia, while RDT may be useful as alternative or complementary method to the DFA and ZnSO4. PCR performance was low, but it allowed determining Giardia B zoonotic assemblage in 25% of the PCR-positive specimens (15 out of 60), while the remaining PCR-positive isolates belonged to the dog-specific assemblage C. The 26% prevalence of G. duodenalis detected by DFA in owned dogs and the identification of potentially zoonotic assemblages underline the potential risk for public health and indicate frequent cross-species transmission of the parasite between humans and dogs.

Anticoccidial and jejunum-protective effects of Krameria lappacea roots extract on experimental Eimeria papillata infection

Coccidiosis is a protozoan parasitic disease caused by Eimeria species and affects wild and domestic animals. Coccidiostats are currently available to control this disease, although drug resistance has been confirmed for all of them. As a result, there is an urgent need to identify eco-friendly agents to control and treat this disease. This study aimed to investigate the ameliorative role of the Krameria lappacea roots extract (KLRE) on the outcome of coccidiosis induced by Eimeria papillata. Male C57BL/6 mice were divided into seven groups (5 mice/group), as follows: Group 1: noninfected-nontreated (control group), Group 2: noninfected-treated group with KLRE (200 mg/kg), Group 3: infected-nontreated group, Group 4: infected-treated group with KLRE (50 mg/kg), Group 5: infected-treated group with KLRE (100 mg/kg), Group 6: infected-treated group with KLRE (200 mg/kg), and Group 7: infected-treated group with amprolium (120 mg/kg). Groups (3-7) were inoculated orally with 1 × 103 sporulated E. papillata oocysts. One hour after infection, groups (4-6) were daily treated for 5 days with KLRE and amprolium. On day 5 postinfection, oocyst output was determined, and mice were euthanized for the collection of jejuna then preparation of histological sections and jejunal homogenate was used for the determination of biochemical and oxidative damage markers. The coccidial infection induced weight loss of mice by 3.971%, which improved after KLRE to -1.512%. After KLRE treatment, the rate of feed intake was improved to be 52.21 ± 2.30 than those in infected group (40.47 ± 2.25). Oocyst output was significantly reduced in mice treated with KLRE (1.308 × 106 oocysts/g.feces) compared with those in the infected group (5.387 × 106 oocysts/g.feces). E. papillata infection induced marked histological alterations within jejunum tissue. After treatment, KLRE was able to impair the development of parasite stages (meronts, gamonts, and developing oocysts) in the jejunum through a significant reduction of number and size in comparison with the infected group. Infection with E. papillata induced a disturbance in the nutrient absorption in the jejunal mice tissue, which improved after the treatment with KLRE and amprolium. Also, KLRE counteracted significantly the E. papillata-induced loss of reduced glutathione and total antioxidant capacity. Our findings indicate that KLRE could be used as an alternative to the available coccidiostats currently available. RESEARCH HIGHLIGHTS: Krameria lappacea exhibit significant anticoccidial and antioxidant activities induced by E. papillata infection. Krameria lappacea exhibit significant improvement in the pathological alterations of the jejunal tissue induced by E. papillata infection.

Gastrointestinal Parasites in Owned Dogs in Serbia: Prevalence and Risk Factors

Dogs are the most popular pets worldwide. Close contact between dogs and people increases the risk of transmission of various zoonotic parasitic infections. Given the importance of veterinary medicine in preserving the One Health concept, the aim of this research was to identify intestinal parasites that may have zoonotic potential and to evaluate risk factors (individual and environmental). The research was conducted in Serbia in 2022 and 2023 on 382 owned dogs, using qualitative methods of coprological examination with a concentration on parasitic elements. The overall prevalence of intestinal parasites was 62.6%, with the following detected: protozoa: Cystoisospora spp. (9.2%), Sarcocystis spp. (4.5%), Neospora caninum/Hammondia spp. (3.7%), Giardia intestinalis (11.8%); nematoda: Toxocara canis (11.5%), Toxascaris leonina (4.2%), family Ancylostomatidae (38.0%), Trichuris vulpis (21.5%), Capillaria spp. (10.5%); trematoda: Alaria alata (1.6%) and cestodes from the Taeniidae family (1.3%). Factors like age, size and coat length, as well as the way of living, attitude and diet were linked to a significantly higher (p < 0.05) prevalence of intestinal parasites. Based on the results of coprological diagnostics, this research indicates the importance of educating dog owners, conducting routine parasitological tests on their pets and regular deworming strategies.

Baiting not-owned dogs against Echinococcus granulosus: innovative tools for integrated control

Cystic echinococcosis (CE), caused by the larval stage of the cestode Echinococcus granulosus, is one of the most widespread zoonoses in Mediterranean countries. Baiting not-owned dogs with praziquantel (PZQ), due to their key role in the maintaining the transmission of CE, currently appears to be the most effective way to limit the transmission of CE, as well as an important aspect to introduce for the control of this parasitic disease. Therefore, this study aims to test 3 types of PZQ-based baits by evaluating different parameters (integrity over time, attractiveness and palatability for dogs, and mechanical resistance after release to different altitudes) and the bait acceptance in field by target animals, i.e. not-owned dogs, by using camera traps. The double PZQ-laced baits (with a double layer of highly palatable chews) showed the greatest resistance in the environment while also preserving the attractiveness and palatability up to 10 days, also withstood heights of 25 m, thus resulting as the most suitable also for drone delivery. The results on the field showed that most of the baits were consumed by not-owned dogs (82.2%), while the remaining were consumed by wild boars (8.9%), foxes (6.7%), badgers (1.1%) and hedgehogs (1.1%), confirming the specific and high attractiveness of the double PZQ-laced baits for the target population and highlights how an anthelmintic baiting programme may be a viable tool for the management of E. granulosus among free-ranging dog populations in endemic rural areas.

FVB/NJ strain as a mouse model for cutaneous leishmaniasis by Leishmania (L.) amazonensis

BACKGROUND

Leishmaniases encompass a spectrum of neglected diseases caused by parasites of the genus Leishmania, grouped in two forms: tegumentary and visceral leishmaniasis.

OBJECTIVES

In this study, we propose Friend Virus B NIH Jackson (FVB/NJ) mouse strain as a new experimental model of infection with Leishmania (Leishmania) amazonensis, the second most prevalent agent of tegumentary leishmaniasis in Brazil.

METHODS AND FINDINGS

We performed in vitro infections of FVB/NJ macrophages and compared them with BALB/c macrophages, showing that BALB/c cells have higher infection percentages and a higher number of amastigotes/cell. Phagocytosis assays indicated that BALB/c and FVB/NJ macrophages have similar capacity to uptake parasites after 5 min incubations. We also investigated promastigotes' resistance to sera from FVB/NJ and BALB/c and observed no difference between the two sera, even though FVB/NJ has a deficiency in complement components. Finally, we subcutaneously infected FVB/NJ and BALB/c mice with 2 × 106 parasites expressing luciferase. Analysis of lesion development for 12 weeks showed that FVB/NJ and BALB/c mice have similar lesion profiles and parasite burdens.

MAIN CONCLUSIONS

This work characterises for the first time the FVB/NJ mouse as a new model for tegumentary leishmaniasis caused by Leishmania (L.) amazonensis.

Genomic survey maps differences in the molecular complement of vesicle formation machinery between Giardia intestinalis assemblages

Giardia intestinalis is a globally important microbial pathogen with considerable public health, agricultural, and economic burden. Genome sequencing and comparative analyses have elucidated G. intestinalis to be a taxonomically diverse species consisting of at least eight different sub-types (assemblages A-H) that can infect a great variety of animal hosts, including humans. The best studied of these are assemblages A and B which have a broad host range and have zoonotic transmissibility towards humans where clinical Giardiasis can range from asymptomatic to diarrheal disease. Epidemiological surveys as well as previous molecular investigations have pointed towards critical genomic level differences within numerous molecular pathways and families of parasite virulence factors within assemblage A and B isolates. In this study, we explored the necessary machinery for the formation of vesicles and cargo transport in 89 Canadian isolates of assemblage A and B G. intestinalis. Considerable variability within the molecular complement of the endolysosomal ESCRT protein machinery, adaptor coat protein complexes, and ARF regulatory system have previously been reported. Here, we confirm inter-assemblage, but find no intra-assemblage variation within the trafficking systems examined. This variation includes losses of subunits belonging to the ESCRTIII as well as novel lineage specific duplications in components of the COPII machinery, ARF1, and ARFGEF families (BIG and CYTH). Since differences in disease manifestation between assemblages A and B have been controversially reported, our findings may well have clinical implications and even taxonomic, as the membrane trafficking system underpin parasite survival, pathogenesis, and propagation.

Persea americana extract protects intestinal tissue from Eimeria papillata-induced murine Infection

Coccidiosis is the most prevalent disease-causing widespread economic loss among farm and domestic animals. Currently, several drugs are available for the control of this disease but resistance has been confirmed for all of them. There is an urgent need, therefore, for the identification of new sources as alternative treatments to control coccidiosis. The present work aimed to study the effect of the Persea americana extract (PAE) as an anti-coccidial, anti-oxidant, and anti-apoptotic modulator during murine intestinal Eimeria papillata infection. A total of 25 male mice were divided into five groups, as follows: Group1: Non-infected-non-treated (negative control), Group2: Non-infected-treated group with PAE (500 mg/kg b.w). Group3: Infected-non-treated (positive control), Group4: Infected-treated group with PAE (500 mg/kg b.w.), and Group5: Infected-treated group with Amprolium (120 mg/kg b.w.). Groups (3-5) were orally inoculated with 1 × 103 sporulated E. papillata oocysts. After 60 min of infection, groups (4 and 5) were treated for 5 consecutive days with the recommended doses of PAE and amprolium. The fact that PAE has an anti-coccidial efficacy against intestinal E. papillata infection in mice has been clarified by the reduction of fecal oocyst output on the 5th day post-infection by about 85.41%. Moreover, there is a significant reduction in the size of each parasite stage in the jejunal tissues of the infected-treated group with PAE. PAE counteracted the E. papillata-induced loss of glutathione peroxidase (GPx), superoxide dismutase (SOD), and total antioxidant capacity (TCA). E. papillata infection also induced an increase in the apoptotic cells expressed by caspase-3 which modulated after PAE treatment. Moreover, the mRNA expression of the goblet cell response gene, mucin (MUC2), was upregulated from 0.50 to 1.20-fold after treatment with PAE. Based on our results, PAE is a promising medicinal plant with anti-coccidial, anti-oxidant, and anti-apoptotic activities and could be used as a food additive.

Lipidome of extracellular vesicles from Giardia lamblia

Extracellular vesicles (EVs) (exossomes, microvesicles and apoptotic bodies) have been well acknowledged as mediators of intercellular communications in prokaryotes and eukaryotes. Lipids are essential molecular components of EVs but at the moment the knowledge about the lipid composition and the function of lipids in EVs is limited and as for now none lipidomic studies in Giardia EVs was described. Therefore, the focus of the current study was to conduct, for the first time, the characterization of the polar lipidome, namely phospholipid and sphingolipid profiles of G. lamblia trophozoites, microvesicles (MVs) and exosomes, using C18-Liquid Chromatography-Mass Spectrometry (C18-LC-MS) and Tandem Mass Spectrometry (MS/MS). A total of 162 lipid species were identified and semi-quantified, in the trophozoites, or in the MVs and exosomes belonging to 8 lipid classes, including the phospholipid classes phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylglycerol (PG), phosphatidylinositol (PI), cardiolipins (CL), the sphingolipid classes sphingomyelin (SM) and ceramides (Cer), and cholesterol (ST), and 3 lipid subclasses that include lyso PC (LPC), lyso PE (LPE) and lyso PG (LPG), but showing different abundances. This work also identified, for the first time, in G. lamblia trophozoites, the lipid classes CL, Cer and ST and subclasses of LPC, LPE and LPG. Univariate and multivariate analysis showed clear discrimination of lipid profiles between trophozoite, exosomes and MVs. The principal component analysis (PCA) plot of the lipidomics dataset showed clear discrimination between the three groups. Future studies focused on the composition and functional properties of Giardia EVs may prove crucial to understand the role of lipids in host-parasite communication, and to identify new targets that could be exploited to develop novel classes of drugs to treat giardiasis.

ZooPathWeb: a comprehensive web resource for zoonotic pathogens

Motivation

Zoonotic pathogens, such as viruses, bacteria, fungi and parasites, can be transmitted from animals to humans, causing a wide range of diseases that can vary from mild to life-threatening. These pathogens typically exhibit a broad host range, infecting domestic and/or wild animals, which serve as reservoirs of infection. Human infection can occur through direct contact with infected animals or their body fluids, consumption of contaminated food or water, or via bites from infected arthropod vectors. Understanding the epidemiological characteristics and population structure of zoonotic pathogens is of paramount importance for preventing and controlling the spread of zoonotic diseases.

Results

Here, we present ZooPathWeb, a comprehensive online resource for zoonotic pathogens. ZooPathWeb provides essential information on pathogens that are particularly relevant to public health and includes a literature collection organized by pathogen classification, such as lineage, host, country or region and publication year. Moreover, we have developed four web-based utility tools for this release: SeqNHandle, PaPhy-ML, TreeView and BLAST. These tools are specifically designed to facilitate the identification of population structure and adaptive evolution in relation to zoonotic pathogens.

Availability and implementation

The ZooPathWeb website is accessed via http://lab.malab.cn/~hrs/zoopathweb/. The source code for AKINND, which is used for collecting pathogen-related literature, can be found at https://github.com/RuiSiHu/AKINND. Additionally, the source code for PaPhy-ML, utilized for phylogenetic analysis, can be found at https://github.com/RuiSiHu/PaPhy-ML.

Supplementary information

Supplementary data are available at Bioinformatics Advances online.

Inhibition of Leishmania infantum Trypanothione Reductase by New Aminopropanone Derivatives Interacting with the NADPH Binding Site

BACKGROUND

As a result of the paucity of treatment, Leishmaniasis continues to provoke about 60,000 deaths every year worldwide. New molecules are needed, and drug discovery research is oriented toward targeting proteins crucial for parasite survival. Among them, trypanothione reductase (TR) is of remarkable interest owing to its vital role in Leishmania species protozoan parasite life. Our previously identified compound 1 is a novel chemotype endowed with a unique mode of TR inhibition thanks to its binding to a formerly unknown but druggable site at the entrance of the NADPH binding cavity, absent in human glutathione reductase (hGR).

METHODS

We designed and synthesized new 3-amino-1-arylpropan-1-one derivatives structurally related to compound 1 and evaluated their potential inhibition activity on TR from Leishmania infantum (LiTR). Cluster docking was performed to assess the binding poses of the compounds.

RESULTS

The newly synthesized compounds were screened at a concentration of 100 μM in in vitro assays and all of them proved to be active with residual activity percentages lower than 75%.

CONCLUSIONS

Compounds 2a and 2b were the most potent inhibitors found, suggesting that an additional aromatic ring might be promising for enzymatic inhibition. Further structure-activity relationships are needed to optimize our compounds activity.

Inactivation of Giardia intestinalis cysts in water using a sonochemical method based on mid-high-frequency waves

Giardia intestinalis is a pollutant of food and water, resistant to conventional disinfection treatments and its elimination requires effective methods action. Herein, mid-high-frequency ultrasound (375 kHz), which produces HO• and H₂O₂, was used as an alternative method of treatment to inactivate Giardia intestinalis cysts in water. The effect of ultrasound power (4.0, 11.2, 24.4 W) on the sonogeneration of radicals was tested, showing that 24.4 W was the condition most favorable to treat the parasite. The viability of the protozoan cysts was evaluated using the immunofluorescence technique and vital stains, showing this protocol was useful to quantify the parasite. The sonochemical method (at 375 kHz and 24.4 W) was applied at different treatment times (10, 20, and 40 min). A significant decrease in the protozoan concentration (reduction of 52.4% of viable cysts) was observed after 20 min of treatment. However, the extension of treatment time up to 40 min did not increase the inactivation. Disinfecting action was associated with attacks on the Giardia intestinalis cyst by sonogenerated HO• and H₂O₂ (which may induce structural damage, even the cell lysis). For future work is recommended to test combinations with UVC or Fenton process to enhance the inactivating action of this method.•Mid-high-frequency ultrasound produces HO• and H₂O₂ profitable to inactivate Giardia intestinalis.•Immunofluorescence technique and vital stains allowed us to quantify the parasite viability.•Giardia intestinalis cysts concentration decreased by 52.4% after only 20 min of sonication.

Co-infection patterns of vector-borne zoonotic pathogens in owned free-ranging dogs in central Chile

We investigated the co-occurrence of the nine of the most relevant canine vector-borne pathogens (CVBP) using conventional and real-time PCR and evaluated risk factors and potential non-apparent haematological alterations associated with co-infection in 111 rural, owned, free-ranging dogs in the Metropolitan Region of Chile.

At least one pathogen was detected in 75% of the dogs. DNA of Anaplasma platys (Ap; 36%), Candidatus Mycoplasma haematoparvum (CMhp; 31%), Mycoplasma haemocanis (Mhc; 28%), Trypanosoma cruzi (17%), Leishmania spp. (4.5%), and Acanthocheilonema reconditum (1%) was detected. All dogs were negative for Ehrlichia spp., Rickettsia spp., Bartonella spp., Piroplasmida, and Hepatozoon spp. Thirty-eight dogs (34%) were coinfected. CMhp was involved in 71%, Mhc in 58%, and Ap in 50% of the co-infections. The most common co-infection pattern was CMhp–Mhc (37% of the cases). The prevalence of Ap was higher in juvenile than in adult dogs, whereas the opposite was found for CMhp and Mhc. Adult dogs were four times more likely of being co-infected than juveniles. Co-infected animals showed higher white blood cell count, segmented neutrophil count, and GGT levels than non-co-infected dogs. Clinically healthy but infected dogs may act as reservoirs of CVBP, and their free-ranging behavior would facilitate the spread of these pathogens to other dogs as well as human beings or wild carnivores.

CD4+ T-lymphocytes from asymptomatic dogs infected with Leishmania infantum are able to activate macrophages for higher leishmanicidal ability in an in vitro co-culture experiment

Dogs are the most common domestic reservoir of Leishmania infantum, making canine visceral leishmaniasis (CVL) a serious public health issue. Identifying new methodologies that can mimic lymphoid and myeloid competence in naturally infected dogs could lower costs and save time in preliminary screenings of potential immunotherapeutic agents and vaccines against CVL. For that, we established a cell-to-cell communication approach between lymphocytes and myeloid cells from healthy, asymptomatic (infected, without apparent clinical signs) and symptomatic (infected with apparent clinical signs) dogs. Peripheral blood mononuclear cells (PBMC) from these dogs were used as source of CD4⁺, CD8⁺ T lymphocytes and macrophages, that were posteriorly infected with L. infantum GFP⁺ promastigotes (green fluorescent protein). Macrophages co-cultured with purified lymphocytes were tested for the ability to control cellular parasitism, and their microbicidal function by producing nitric oxide (NO) and reactive oxygen species (ROS). The kind of T cell response within the co-culture was also evaluated, by assessing their ability to produce interferon-gamma (IFN-γ) and interleukin 4 (IL-4). The data suggests that T lymphocytes from symptomatic dogs are more prone to produce IL-4 than the ones from asymptomatic dogs. Macrophages from asymptomatic dogs also demonstrated a higher microbicidal potential, with increased levels of NO and ROS production, compared to symptomatic dogs, mainly in highly parasitized cells. Together, our results identify the ratio of IL-4/IFN-γ produced by CD4⁺ and CD8⁺ T cells, as well as, the ratio between parasite GFP signal/NO and ROS signal in macrophages as potential immunological biomarkers of failure and success of the screened agents. Our findings also propose a reliable methodology that can be used to follow the immune response in trials of potential drugs or vaccines targeting CVL.

Differential microRNAs expression during ex vivo infection of canine and ovine placental explants with Trypanosoma cruzi and Toxoplasma gondii

Trypanosoma cruzi and Toxoplasma gondii are two zoonotic parasites that constitute significant human and animal health threats, causing a significant economic burden worldwide. Both parasites can be transmitted congenitally, but transmission rates for T. gondii are high, contrary to what has been observed for T. cruzi. The probability of congenital transmission depends on complex interactions between the pathogen and the host, including the modulation of host cell gene expression by miRNAs. During ex vivo infection of canine and ovine placental explants, we evaluated the expression of 3 miRNAs (miR-30e-3p, miR-3074-5p, and miR-127-3p) previously associated with parasitic and placental diseases and modulated by both parasites. In addition, we identified the possible target genes of the miRNAs by using computational prediction tools and performed GO and KEGG enrichment analyses to identify the biological functions and associated pathologies. The three miRNAs are differentially expressed in the canine and ovine placenta in response to T. cruzi and T. gondii. We conclude that the observed differential expression and associated functions might explain, at least partially, the differences in transmission rates and susceptibility to parasite infection in different species.

Rare Occurrence of Blastocystis in Pet Animals and Their Owners in the Pomeranian Voivodeship in Poland in the Light of Literature Data

Blastocystis is an intestinal microeukaryote with ambiguous pathogenicity, commonly detected in human feces worldwide. It comprises at least 28 genetically diverse subtypes (STs), 12 of which also occur in a wide range of animal species, giving rise to suspicion of zoonotic transmission. To investigate this, we conducted a molecular study of 145 stool samples of pet animals, and 67 of their owners, living in an urban area in Poland. Blastocystis was detected in only three (2.1%) animal samples (of two bearded agamas and a leopard gecko), while all dogs, cats, and pet rodents were Blastocystis-negative. Blastocystis was also present in three (4.5%) owners of animals, but they were cat owners, not reptile owners, and the subtypes identified in them differed significantly from those of reptiles. Additionally, the frequency of Blastocystis in different groups of dogs (depending on how they were kept) was analyzed. This work is the first to find Blastocystis in pet reptiles, and we encourage further investigation of Blastocystis in this poorly examined group of animals, as well as continued study on the transmission of this microorganism between humans and animals.

The Pathogenicity and Virulence of Leishmania - interplay of virulence factors with host defenses

Leishmaniasis is a group of disease caused by the intracellular protozoan parasite of the genus Leishmania. Infection by different species of Leishmania results in various host immune responses, which usually lead to parasite clearance and may also contribute to pathogenesis and, hence, increasing the complexity of the disease. Interestingly, the parasite tends to reside within the unfriendly environment of the macrophages and has evolved various survival strategies to evade or modulate host immune defense. This can be attributed to the array of virulence factors of the vicious parasite, which target important host functioning and machineries. This review encompasses a holistic overview of leishmanial virulence factors, their role in assisting parasite-mediated evasion of host defense weaponries, and modulating epigenetic landscapes of host immune regulatory genes. Furthermore, the review also discusses the diagnostic potential of various leishmanial virulence factors and the advent of immunomodulators as futuristic antileishmanial drug therapy.

Prevalence and genetic diversity of Giardia duodenalis in pet dogs from Zhengzhou, central China and the association between gut microbiota and fecal characteristics during infection

As a common zoonotic intestinal parasite, Giardia duodenalis could infect humans and various mammals worldwide, including pet dogs, leading to giardiasis. This study detected the infection of G. duodenalis in asymptomatic pet dogs in Zhengzhou, and evaluated the possibility of zoonosis and the relationship between gut microbiota and fecal characteristics. We randomly collected 448 fresh fecal samples from Zhengzhou, and G. duodenalis was screened based on the beta-giardin (bg), glutamate dehydrogenase (gdh), and triose phosphate isomerase (tpi) genes. The difference of gut microbiota between five G. duodenalis-positive and five G. duodenalis-negative samples was investigated by 16S rRNA gene sequencing. The overall prevalence of G. duodenalis was 7.1% (32/448) based on bg, gdh, and tpi locus, two G. duodenalis assemblages (C = 13, D = 14) and five (15.6%) mixed infection (C + D) were identified. Moreover, compared with the G. duodenalis-negative group, the diversity of gut microbiota increased in G. duodenalis-positive group. The decrease of Lactobacillus spp. and considerable increase of Prevotella spp. were associated with the fecal characteristics. These results show that the transmission of zoonotic giardiasis between humans and pet dogs is rare in Zhengzhou, central China, and support the use of Lactobacillus spp. as a potential probiotic agent to improve intestinal health in dogs, or even humans, by treating G. duodenalis. Therefore, the public health significance of G. duodenalis to humans, companion animals, and the environment should be further evaluated from One Health perspective.

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Prevalence of G. duodenalis was 7.1% in pet dogs in Zhengzhou, central China.

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G. duodenalis assemblage D infection is associated to higher gut microbial diversity.

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The abundance of Prevotella and Lactobacillus may affect fecal characteristics.

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Lactobacillus may be used as a potential feed additive to treat giardiasis.

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Effective strategies should be taken to minimize the threat posed by G. duodenalis.

Pet Owners' Perceptions of COVID-19, Zoonotic Disease, and Veterinary Medicine: The Impact of Demographic Characteristics

This study aimed to investigate the impact of sociodemographic characteristics on pet owners' concern about the transmission of zoonotic disease and SARS-CoV-2, and to describe owners' perceptions of veterinarians and physicians as resources for zoonoses information. Between September and October 2020, 1154 individuals completed an online survey via Qualtrics. Binary logistic regression models were used to examine the associations between owner demographics and perceptions of zoonoses and SARS-CoV-2. Most participants were minimally concerned about their pets contracting or transmitting zoonotic diseases or SARS-CoV-2, although perceptions of risk differed based on age, race, and education. Older participants were typically less concerned about the transmission of zoonotic diseases and SARS-CoV-2. Considering where participants obtained information about zoonoses, pet owners were more likely to contact their veterinarian for advice (43%) than their physician (17%). However, 17% of pet owners struggled to access veterinary care, and 51% said their access to veterinary care had become more difficult during the COVID-19 pandemic. Our findings highlight a need for further education about zoonoses and SARS-CoV-2, and suggest veterinarians may play a key role in these communications. The results also emphasize the need to address access to care issues in veterinary medicine.

Molecular detection of Trypanosoma (Trypanosomatidae) in bats from Thailand, with their phylogenetic relationships

The vast majority of trypanosome species is vector-borne parasites, with some of them being medically and veterinary important (such as Trypanosoma cruzi and Trypanosoma brucei) and capable of causing serious illness in vertebrate hosts. The discovery of trypanosomes in bats emphasizes the importance of bats as an important reservoir. Interestingly, there is a hypothesis that bats are ancestral hosts of T. cruzi. Trypanosome diversity has never been investigated in bats in Thailand, despite being in a biodiversity hot spot. To gain a better understanding of the diversity and evolutionary relationship of trypanosomes, polymerase chain reaction-based surveys were carried out from 2018 to 2020 in 17 sites. A total of 576 bats were captured, representing 23 species. A total of 38 (6.6%) positive samples was detected in ten bat species. Trypanosoma dionisii and Trypanosoma noyesi were identified from Myotis siligorensis and Megaderma spasma, respectively. The remaining 18S rRNA sequences of trypanosomes were related to other trypanosomes previously reported elsewhere. The sequences in the current study showed nucleotide identity as low as 90.74% compared to those of trypanosomes in the GenBank database, indicating the possibility of new species. All bat trypanosomes identified in the current study fall within the T. cruzi clade. The current study adds to evidence linking T. noyesi to a bat trypanosome and further supports the bat host origin of the T. cruzi clade. To the best of authors' knowledge, this is the first study on bat trypanosomes in Thailand and their phylogenetic relationships with global isolates.

The controversies surrounding Giardia intestinalis assemblages A and B

Giardia intestinalis continues to be one of the most encountered parasitic diseases around the world. Although more frequently detected in developing countries, Giardia infections nonetheless pose significant public health problems in developed countries as well. Molecular characterisation of Giardia isolates from humans and animals reveals that there are two genetically different assemblages (known as assemblage A and B) that cause human infections. However, the current molecular assays used to genotype G. intestinalis isolates are quite controversial. This is in part due to a complex phenomenon where assemblages are incorrectly typed and underreported depending on which targeted locus is sequenced. In this review, we outline current knowledge based on molecular epidemiological studies and raise questions as to the reliability of current genotyping assays and a lack of a globally accepted method. Additionally, we discuss the clinical symptoms caused by G. intestinalis infection and how these symptoms vary depending on the assemblage infecting an individual. We also introduce the host-parasite factors that play a role in the subsequent clinical presentation of an infected person, and explore which assemblages are most seen globally.

Domestic mammals as reservoirs for Leishmania donovani on the Indian subcontinent: Possibility and consequences on elimination

Leishmania donovani is the causative agent of historically anthroponotic visceral leishmaniasis (VL) on the Indian subcontinent (ISC). L. donovani is transmitted by the sand fly species Phlebotomus argentipes. Our collaborative group and others have shown that sand flies trapped outside in endemic villages have fed on cattle and dogs in addition to people. Domestic animals are reservoirs for L. donovani complex spp., particularly L. infantum, in other endemic areas. Multiple studies using quantitative PCR or serological detection methods have demonstrated that goats, cattle, rats and dogs were diagnostically positive for L. donovani infection or exposure in eastern Africa, Bangladesh, Nepal and India. There is a limited understanding of the extent to which L. donovani infection of domestic animals drives transmission to other animals or humans on the ISC. Evidence from other vector-borne disease elimination strategies indicated that emerging infections in domestic species hindered eradication. The predominant lesson learned from these other situations is that non-human reservoirs must be identified, controlled and/or prevented. Massive efforts are underway for VL elimination on the Indian subcontinent. Despite these herculean efforts, residual VL incidence persists. The spectre of an animal reservoir complicating elimination efforts haunts the final push towards full VL control. Better understanding of L. donovani transmission on the Indian subcontinent and rigorous consideration of how non-human reservoirs alter VL ecology are critical to sustain elimination goals.

Assessment of the oxidative status and goblet cell response during eimeriosis and after treatment of mice with magnesium oxide nanoparticles

Magnesium nanoparticles have been the focus of study over the past few years because of its functionality in the body. Assessment of the impact of magnesium oxide nanoparticles (MgNPs) on eimeriosis has yet to be conducted. The goal of this study was to see how MgNPs affected the parasite Eimeria papillata infected jejunum. To induce eimeriosis, mice were infected with sporulated oocysts. For treatment, 5 mg / Kg MgNPs was used for 5 consecutive days. The infection reduced the number of intestinal goblet cells and their associated genes MUC2 and MUC4, as well as increasing oxidative damage in the jejunum. MgNPs significantly reduced the oocyst production in the feces by about 77 %. After treatment, the number of goblet cells per villus increased from 4.17% to 7.40.6%. Moreover, the MgNPs were able to upregulate the expression of MUC2 and MUC4-mRNA. MgNPs significantly increased the activity of catalase and superoxide dismutase, as well as the extent of glutathione, by day 5 after infection with the parasite. On contrary, MgNPs decreased the level of malondialdehyde and nitric oxide. The findings suggested that MgNPs could be an effective anti-eimeriosis agent due to their anti-eimerial and anti-oxidant roles, as well as the regulatory effect on the goblet cell mucin genes in the jejunum of mice.

Toxoplasma gondii infection in pet cats and their owners in northeastern China:an important public health concern

Background

Limited information about Toxoplasma gondii infection in pet cats and their owners is available in China.

Methods

In this study, blood samples were randomly collected from 306 pet cats and 397 corresponding pet owners in Jilin province, northeastern China. Sera from the pet cats and the pet owners were tested for anti-T. gondii antibodies using an modified agglutination test (MAT) and an enzyme-linked immunosorbent assay (ELISA), respectively. Moreover, the risk factors for T. gondii infection in pet cats and corresponding pet owners were explored.

Result

In total, 62 sera out of 306 examined pet cats (20.3%) and 18.1% (72/397) pet cat owners were seropositive for T. gondii, respectively. The results of statistical analysis showed that both pet cats and their owners from rural area had significantly higher T. gondii seroprevalence than those from urban area (p < 0.001). Moreover, owners of pet cas who have the knowledge of zoonotic protozoan diseases had a significantly lower T. gondii seroprevalence than those without the knowledge of zoonotic protozoan diseases (p < 0.001).

Conclusions

The present results revealed that the seroprevalence of T. gondii infection are widespread in pet cats and their owners in Jilin province, northeastern China. Residence area and understanding knowledge of zoonotic protozoan diseases are considered to be raleted to the T. gondii infection. Hence, it is necessary to highlight the dangers and protection methods of zoonotic protozoan diseases caused by pet cats, especially in rural area.

Prevalence, Risk Factors and Genotypes of Giardia duodenalis in Sheltered Dogs in Tuscany (Central Italy)

In sheltered dogs, the prevalence of Giardia duodenalis is frequently high and may include potential zoonotic genotypes. The prevalence, genotypes and potential risk factors of G. duodenalis were assessed in 168 dogs from four kennels (Pistoia, Prato, Florence, Valdarno) in Tuscany, central Italy and compared with data from previous Italian studies. The prevalence of other intestinal parasites was also investigated. Individual dog faecal samples collected from each kennel were examined by parasitological techniques and a rapid immunoassay for the detection of G. duodenalis and Cryptosporidium faecal antigens. On Giardia-positive samples, molecular analysis was performed for genotype identification. Overall, 69 dogs scored positive for G. duodenalis (41%), but significant differences (p ≤ 0.05) were found among the four kennels and sampling seasons. The potentially zoonotic assemblages A and B and the canine-specific assemblage C (Pistoia: A-AII, B, C; Prato: A-AII, B; Florence: A-AII; Valdarno: A and C) were identified. Toxocara canis (8.9%), Trichuris vulpis (3.6%), hookworms (1.19%) and Cryptosporidium sp. (0.6%) were also identified. The high prevalence of G. duodenalis and the identification of potentially zoonotic genotypes in all examined kennels underline the need to improve routine parasite monitoring and control measures and to provide insights into the zoonotic potential of G. duodenalis.

Toxoplasma gondii Induces Apoptosis via Endoplasmic Reticulum Stress-Derived Mitochondrial Pathway in Human Small Intestinal Epithelial Cell-Line

Toxoplasma gondii, an intracellular protozoan parasite that infects one-third of the world’s population, has been reported to hijack host cell apoptotic machinery and promote either an anti- or proapoptotic program depending on the parasite virulence and load and the host cell type. However, little is known about the regulation of human FHs 74 small intestinal epithelial cell viability in response to T. gondii infection. Here we show that T. gondii RH strain tachyzoite infection or ESP treatment of FHs 74 Int cells induced apoptosis, mitochondrial dysfunction and ER stress in host cells. Pretreatment with 4-PBA inhibited the expression or activation of key molecules involved in ER stress. In addition, both T. gondii and ESP challenge-induced mitochondrial dysfunction and cell death were dramatically suppressed in 4-PBA pretreated cells. Our study indicates that T. gondii infection induced ER stress in FHs 74 Int cells, which induced mitochondrial dysfunction followed by apoptosis. This may constitute a potential molecular mechanism responsible for the foodborne parasitic disease caused by T. gondii.

Nutritional Modulation of the Immune Response Mediated by Nucleotides in Canine Leishmaniosis

Leishmaniasis is an emerging, uncontrolled, and neglected zoonotic disease. Climate change is contributing to its ongoing global expansion. The dog is the main reservoir; hence the importance of implementing effective treatment, prevention, and control measures in this animal species to protect public health. However, although the standard treatment for canine leishmaniosis (CanL) is effective, it does not provide full parasitological clearance, and side effects and drug resistance have been described. The host's immune system plays a key role in the establishment and evolution of leishmaniasis. Dietary nucleotides modulate the immune response and, given their reported efficacy and safety in sick and clinically healthy Leishmania-infected dogs and because they represent a sustainable option with no associated side effects or resistance, they could be included within the prevention, treatment, and control strategies for leishmaniasis. This article briefly summarizes the scientific literature on CanL management, including unresolved issues, and reviews the scientific evidence on immunomodulatory effects of dietary nucleotides in different animal species. It also proposes a CanL management algorithm, including nucleotides. It is concluded that nutritional modulation of the immune response with nucleotides can contribute to better management of leishmaniasis following a One Health approach, especially in the COVID-19 era.

Canine and Feline Parasitology: Analogies, Differences, and Relevance for Human Health

Cats and dogs are treated as family members by most pet owners. Therefore, a high quality of veterinary care and preventive medicine is imperative for animal health and welfare and for the protection of humans from zoonotic pathogens. There is a general perception of cats being treated as "small dogs," especially in the field of clinical parasitology. As a result, several important differences between the two animal species are not taken into proper consideration and are often overlooked. Dogs and cats are profoundly different under evolutionary, biological, ethological, behavioral, and immunological standpoints. These differences impact clinical features, diagnosis, and control of canine and feline parasites and transmission risk for humans. This review outlines the most common parasitoses and vector-borne diseases of dogs and cats, with a focus on major convergences and divergences, and discusses parasites that have (i) evolved based on different preys for dogs and cats, (ii) adapted due to different immunological or behavioral animal profiles, and (iii) developed more similarities than differences in canine and feline infections and associated diseases. Differences, similarities, and peculiarities of canine and feline parasitology are herein reviewed in three macrosections: (i) carnivorism, vegetarianism, anatomy, genetics, and parasites, (ii) evolutionary adaptation of nematodes, including veterinary reconsideration and zoonotic importance, and (iii) behavior and immune system driving ectoparasites and transmitted diseases. Emphasis is given to provide further steps toward a more accurate evaluation of canine and feline parasitology in a changing world in terms of public health relevance and One Health approach.

An Update on Zoonotic Cryptosporidium Species and Genotypes in Humans

The enteric parasite, Cryptosporidium is a major cause of diarrhoeal illness in humans and animals worldwide. No effective therapeutics or vaccines are available and therefore control is dependent on understanding transmission dynamics. The development of molecular detection and typing tools has resulted in the identification of a large number of cryptic species and genotypes and facilitated our understanding of their potential for zoonotic transmission. Of the 44 recognised Cryptosporidium species and >120 genotypes, 19 species, and four genotypes have been reported in humans with C. hominis, C. parvum, C. meleagridis, C. canis and C. felis being the most prevalent. The development of typing tools that are still lacking some zoonotic species and genotypes and more extensive molecular epidemiological studies in countries where the potential for transmission is highest are required to further our understanding of this important zoonotic pathogen. Similarly, whole-genome sequencing (WGS) and amplicon next-generation sequencing (NGS) are important for more accurately tracking transmission and understanding the mechanisms behind host specificity.

Advances in Understanding Vector Behavioural Traits after Infection

Vector behavioural traits, such as fitness, host-seeking, and host-feeding, are key determinants of vectorial capacity, pathogen transmission, and epidemiology of the vector-borne disease. Several studies have shown that infection with pathogens can alter these behavioural traits of the arthropod vector. Here, we review relevant publications to assess how pathogens modulate the behaviour of mosquitoes and ticks, major vectors for human diseases. The research has shown that infection with pathogens alter the mosquito’s flight activity, mating, fecundity, host-seeking, blood-feeding, and adaptations to insecticide bed nets, and similarly modify the tick’s locomotion, questing heights, vertical and horizontal walks, tendency to overcome obstacles, and host-seeking ability. Although some of these behavioural changes may theoretically increase transmission potential of the pathogens, their effect on the disease epidemiology remains to be verified. This study will not only help in understanding virus–vector interactions but will also benefit in establishing role of these behavioural changes in improved epidemiological models and in devising new vector management strategies.

Feline Leishmaniosis: An Emerging Public Health Problem

Leishmaniosis is the third most important vector-borne disease in humans, preceded by malaria and lymphatic filariasis, and it is considered endemic in tropical and subtropical areas, where higher temperatures favor development of its vector, sandflies. This zoonotic disease is caused by infection of protozoa Leishmania spp. and the most serious mucocutaneous and visceral form is produced by Leishmania infantum, which predominates in the Mediterranean region. The usual hosts for this parasite are dogs and humans, but an increment in cases of L. infantum infection has been observed in cats in the last years. This increase could be due to the use of sandflies repellents in dogs, obligating the parasite to looking for other hosts. The role of cats in the epidemiology of this disease is unknown, although increase of prevalence of feline leishmaniosis has been observed in endemic areas in the last years. Diagnostic techniques and treatments in cats are not standardized, which makes it difficult to establish prevalence and epidemiology of feline leishmaniosis. Furthermore, the clinical signs and immune response against Leishmania in cats are different to those in dogs, with an observed increment of drug resistance. It is necessary to increase our knowledge about L. infantum infection in cats, including clinical signs, transmission, treatments, and the role of cats in the increasing of zoonoses. Finally, new alternative treatments are required for controlling the spread of this disease in all species of mammals.

Preclinical Studies in Anti-Trypanosomatidae Drug Development

The trypanosomatid parasites Trypanosoma brucei, Trypanosoma cruzi and Leishmania are the causative agents of human African trypanosomiasis, Chagas Disease and Leishmaniasis, respectively. These infections primarily affect poor, rural communities in the developing world, and are responsible for trapping sufferers and their families in a disease/poverty cycle. The development of new chemotherapies is a priority given that existing drug treatments are problematic. In our search for novel anti-trypanosomatid agents, we assess the growth-inhibitory properties of >450 compounds from in-house and/or "Pathogen Box" (PBox) libraries against L. infantum, L. amazonensis, L.braziliensis, T. cruzi and T. brucei and evaluate the toxicities of the most promising agents towards murine macrophages. Screens using the in-house series identified 17 structures with activity against and selective toward Leishmania: Compounds displayed 50% inhibitory concentrations between 0.09 and 25 μM and had selectivity index values >10. For the PBox library, ~20% of chemicals exhibited anti-parasitic properties including five structures whose activity against L. infantum had not been reported before. These five compounds displayed no toxicity towards murine macrophages over the range tested with three being active in an in vivo murine model of the cutaneous disease, with 100% survival of infected animals. Additionally, the oral combination of three of them in the in vivo Chagas disease murine model demonstrated full control of the parasitemia. Interestingly, phenotyping revealed that the reference strain responds differently to the five PBox-derived chemicals relative to parasites isolated from a dog. Together, our data identified one drug candidate that displays activity against Leishmania and other Trypanosomatidae in vitro and in vivo, while exhibiting low toxicity to cultured mammalian cells and low in vivo acute toxicity.