Current world status of Balantidium coli

Prevalence and molecular characterisation of Balantioides coli in pigs raised in Italy

Balantioides coli is the only ciliated protist of both human and veterinary interest and colonises the large intestine of several hosts, including humans and pigs. Given the scarcity of data on B. coli circulation in pigs in Italy, a study was planned to record its prevalence and genetic types and compare the analytical sensitivity of two copromicroscopic techniques. For this purpose, 880 faecal samples were collected from pigs raised in 22 farms located in northern Italy and analysed with the sedimentation and the FLOTAC® dual technique, employing sodium chloride and zinc sulphate flotation solutions, and the Cohen's kappa coefficient was calculated to assess the agreement between these methods. Conventional PCR to amplify the ribosomal internal transcribed spacer region (ITS) was subsequently performed on 22 samples, one for each farm, which were positive for B. coli cysts by sedimentation; when more than one sequence was detected in the chromatograms, the PCR products were cloned. Overall, 813 samples were positive for B. coli cysts by sedimentation (92.4%), and moderate concordance with the zinc-based FLOTAC® technique was observed, whereas the agreement was slight with the salt-based FLOTAC® technique. Among the 22 sequenced samples, type B was amplified in 19 samples, type A in two samples, and both A and B types were co-expressed in one sample. This study demonstrated a high prevalence of B. coli in Italian pigs; further insights are needed to trace its distribution and genetic polymorphism in other pig production categories and in humans, defining its public health significance.

Diversity of the Amoebozoa and Ciliophora Groups in Non-Human Primates Kept Ex Situ and in Their Handlers in Different Institutions in Brazil

Parasitic infections in non-human primates (NHPs) kept ex situ can be caused by zoonotic protists like Balantioides coli and Entamoeba histolytica. In Brazil, little is known about these infections in neotropical species. This study aimed to identify Amoebozoa and Ciliophora groups in fecal samples through in vitro isolation and molecular analysis, mapping their distribution in Brazil. Among 511 NHP and 74 handler's fecal samples, Amoebozoa were found in 61 (11.9%) NHP samples, and Ciliophora in 6 (1.2%). Amoebic cysts were present in 12 (16.2%) human samples. Iodamoeba sp. from S. xanthosternos, E. coli from a handler, and B. coli from P. troglodytes and A. guariba were isolated in vitro. Molecular techniques identified E. dispar (34.2%), E. histolytica (5.1%), E. hartmanni (26.6%), E. coli (15.2%), Iodamoeba sp. (12.6%), E. nana (8.9%), and B. coli (7.6%). Greater protist diversity occurred in northern and southeastern regions, with E. histolytica and B. coli detected in endangered species, such as Saguinus bicolor and Alouatta guariba. Protist overlap between humans and NHPs underscores zoonotic risks. This study presents the first molecular characterization of Amoebozoa and Ciliophora in neotropical NHPs kept ex situ in Brazil, highlighting the need for improved hygiene and management protocols in primate institutions.

Modes and mechanisms for the inheritance of mitochondria and plastids in pathogenic protists

Pathogenic protists are responsible for many diseases that significantly impact human and animal health across the globe. Almost all protists possess mitochondria or mitochondrion-related organelles, and many contain plastids. These endosymbiotic organelles are crucial to survival and provide well-validated and widely utilised drug targets in parasitic protists such as Plasmodium and Toxoplasma. However, mutations within the organellar genomes of mitochondria and plastids can lead to drug resistance. Such mutations ultimately challenge our ability to control and eradicate the diseases caused by these pathogenic protists. Therefore, it is important to understand how organellar genomes, and the resistance mutations encoded within them, are inherited during protist sexual reproduction and how this may impact the spread of drug resistance and future therapeutic approaches to target these organelles. In this review, we detail what is known about mitochondrial and plastid inheritance during sexual reproduction across different pathogenic protists, often turning to their better studied, nonpathogenic relatives for insight.

Gastrointestinal Parasites With Their Risk Factors in Tharu Indigenous People in Southern Nepal: A Cross-Sectional Study

Background

Globally, gastrointestinal (GI) infections are common, particularly in populations with low socioeconomic levels, including high illiteracy rates, ignorance, poor housing and lifestyles, and unfavorable environmental conditions. These risk factors are the underlying cause of GI parasitic infections in many developing nations, including Nepal.

Aim

This study aimed to assess the prevalence and diversity of GI parasites and their association with a few risk factors within the marginalized indigenous Tharu people of the southern region of Nepal.

Methods

A purposive sampling method was used to collect stool samples from Tharu indigenous people (N = 179) in Thaskaul, Kolhabi, Bara, Nepal. The samples were preserved in a 2.5% potassium dichromate solution. The samples were analyzed by direct wet mount and acid-fast staining techniques and examined at 40×, 100×, 400×, and 1000× magnifications.

Results

Out of 179 stool samples, the prevalence rate of the GI parasites was 42.46% (n = 76), out of which females (43.00%, 43/100) had a slightly higher prevalence rate than males (41.77%, 33/79) (p > 0.05, chi-square tests at 95% confidence level). Out of nine species of GI parasites, the prevalence of Cryptosporidium spp. was highest among protozoa (30.17%, n = 54), whereas that of Ascaris lumbricoides was highest among helminths (5.59%, n = 10). Occupation, animal husbandry, parasitologic knowledge, drinking water sources, pork-feeding habit, diarrheal or stomachache symptoms, and drug-consuming history were associated with one or more GI parasitosis (p < 0.05).

Conclusion

The moderate prevalence and diversity of GI parasitism in the Tharu population suggests the need for effective, efficient, and timely preventative and control measures in the study area. Further One Health Approach, by conducting studies that involve the examination of samples from the local populations, livestock, food, water, and soil, would be important.

Prevalence of gastrointestinal parasites in domestic pigs from family farms in northeastern Argentina

Domestic pigs serve as significant hosts and reservoirs for multiple parasite species, some specific to pigs and many others of zoonotic importance. This study aimed to assess the prevalence of intestinal parasites in pigs within a rural area in northeastern Argentina. We also examined demographic information, breeding conditions, and exposure factors associated with parasite presence. Pig feces were subjected to coprological examination through flotation and sedimentation techniques. Modified Ziehl-Neelsen technique was employed to examine oocysts of Cryptosporidium spp. In total, 29 family farms with pig pens were analyzed, and 42 stool samples were collected from pigs on these farms. At the farm level, the presence of at least one parasite species was recorded in 27 rural houses (93.1%). We found that 90.4% of pigs were parasitized, with a specific parasitoses of 10 species, with a maximum of six species in a single host. The most prevalent protozoa were Entamoeba spp. (57.1%) and Blastocystis sp. (45.2%), followed by Iodamoeba butschlii (33.3%), Neobalantidium coli (21.4%), coccidia (14.2%), Cryptosporidium spp. (9.5%) and Giardia spp. (2.3%). The most prevalent helminths were Strongylidae eggs (52.3%), Ascaris spp. (14.2%) and Trichuris spp. (2.3%). We advocate for an urgent need to implement a comprehensive prophylaxis program prioritizing general hygiene practices such as regular cleaning, removal of fecal material and renewal of drinking water. Additionally, vaccination and deworming protocols should be implemented. Furthermore, this study highlights the necessity for molecular-level evaluations to detect potential zoonotic genotypes of the identified protozoa.

The Phylogenetic Characterization of Balantioides coli Isolated in the Pavlova Culture Medium Supplemented with Coconut Water and Animal Serum

Balantioides coli is a ciliated protist that can cause dysentery in humans, pigs and nonhuman primates and may have the potential for zoonotic transmission. Its diagnosis is routinely performed through conventional parasitological techniques, and few studies have used culturing techniques to isolate it, applying molecular tools for the characterization of this protozoan. Thus, the objective of this study was to confirm B. coli diagnosis using molecular tools and to characterize the genetic variants of this parasite isolated from pigs kept on family farms in Brazil using three different culture media that differed in the serum added. Fecal samples from pigs were inoculated in Pavlova medium plus coconut water (PC), fetal bovine serum (PB) and horse serum (PH). Of the 127 samples positive for forms compatible with the phylum Ciliophora, 31 were selected for isolation. The most successful medium for isolation was PB 19/31 (61.3%), followed by PH 18/31 (58.1%) and PC 11/31 (35.5%). Of the nucleotide sequences generated, 20 were classified as genetic variant type B0, two as A1 and 15 as A0. The results indicated that PC, despite having allowed the isolation of B. coli for a short period, was not an adequate medium for the maintenance of this parasite in vitro, therefore requiring improvement.

Symbionts of Ciliates and Ciliates as Symbionts

Endosymbiotic relationships between ciliates and others are critical for their ecological roles, physiological adaptations, and evolutionary implications. These can be obligate and facultative. Symbionts often provide essential nutrients, contribute to the ciliate's metabolism, aid in digestion, and offer protection against predators or environmental stressors. In turn, ciliates provide a protected environment and resources for their symbionts, facilitating their survival and proliferation. Ultrastructural and full-cycle rRNA approaches are utilized to identify these endosymbionts. Fluorescence in situ hybridization using "species- and group-specific probes" which are complementary to the genetic material (DNA or RNA) of a particular species or group of interest represent convenient tools for their detection directly in the environment. A systematic survey of these endosymbionts has been conducted using both traditional and metagenomic approaches. Ciliophora and other protists have a wide range of prokaryotic symbionts, which may contain potentially pathogenic bacteria. Ciliates can establish symbiotic relationships with a variety of hosts also, ranging from protists to metazoans. Understanding ciliate symbiosis can provide useful insights into the complex relationships that drive microbial communities and ecosystems in general.

Case Report: A rare instance of acute appendicitis induced by Balantidium Coli parasitic infection

Introduction

Acute appendicitis secondary to parasitic infections is uncommon, being detected in less than 1% of cases. Balantidium coli is a parasite found in pigs and primates with zoonotic potential. To date, only three cases of acute appendicitis induced by this parasite have been documented globally.

Case

A 7-year-old female patient, who consumed pork daily, presented to the emergency department with a one-day history of abdominal pain in the lower quadrants, described as colic-like, alongside abdominal distension. Initial abdominal radiography led to a diagnosis of intestinal obstruction. Conservative management without therapeutic response necessitated referral to a higher complexity center. Upon admission, an abdominal computed tomography scan diagnosed acute appendicitis and secondary ileus. During surgical intervention, an appendiceal phlegmon formed by loops of the small intestine was mechanically released, revealing a perforated appendix with extensive fecal peritoneal contamination. Pathological analysis identified an inflammatory infiltrate and the presence of Balantidium coli trophozoites. Medical treatment included Piperacillin-Tazobactam and Metronidazole. The patient was discharged after 10 days of medical treatment.

Discussion

Acute appendicitis caused by Balantidium coli is a rare occurrence. It is crucial to identify parasites in pathological samples due to their impact on postoperative management. The close contact between humans and pigs, especially in developing countries, suggests that the prevalence of parasitic infection and colonization by Balantidium coli may be higher than currently recognized. Regarding the identification of this patient's specific exposure, the regular consumption of pork suggests the hypothesis that improper processing is linked to the acquisition of the parasitic infection.

Gut protozoa of wild rodents - a meta-analysis

Protozoa are well-known inhabitants of the mammalian gut and so of the gut microbiome. While there has been extensive study of a number of species of gut protozoa in laboratory animals, particularly rodents, the biology of the gut protozoa of wild rodents is much less well-known. Here we have systematically searched the published literature to describe the gut protozoa of wild rodents, in total finding records of 44 genera of protozoa infecting 228 rodent host species. We then undertook meta-analyses that estimated the overall prevalence of gut protozoa in wild rodents to be 24%, with significant variation in prevalence among some host species. We investigated how host traits may affect protozoa prevalence, finding that for some host lifestyles some protozoa differed in their prevalence. This synthesis of existing data on wild rodent gut protozoa provides a better understanding of the biology of these common gut inhabitants and suggests directions for their future study.

Isolated Balantidium coli in a 1.5-Year-Old Boy: A Case Report

PURPOSE

Balantidium coli, is a protozoa that can infect humans. Balantidium coli infection is mostly asymptomatic, but can cause of diarrhea, abdominal pain and sometimes perforated colon. There are only few previous reports regarding the infant balantidiasis and there is a little information about its clinical signs and treatment. In Islamic countries pig farming and consumption is prohibited and reservoir host is unknown.

METHODS

1.5 years old boy showed sever anorexia and diarrhea. The affected infant was depressed. The evaluation of fecal examination revealed a large number of B. coli trophozoites and cysts leaded us to an uncommon presentation of B. coli in the infant.

RESULTS

A few reports of human balantidiasis from Iran seems quite extraordinary. Wild boars have been proposed the responsible for transmission of human infection in Iran.

CONCLUSION

However, this report as the first report of infant balantidiasis in Iran supports the role of other sources and domestic or wild animals as reservoir hosts for B. coli in Iran.

Prevalence and sequence diversity of Balantioides coli in pigs in Xinjiang, China

Balantioides coli is a common intestinal parasitic protozoan in pigs. In the present study, 801 fecal samples of pigs from seven farms in Xinjiang were analyzed based on the ITS1-5.8S rRNA-ITS2 gene. The prevalence of B. coli was 4.2% (34/801), with the highest prevalence of 18.9% (18/95) occurring in Alaer, Xinjiang. B. coli was detected in all age groups (pre-weaned pigs, post-weaned pigs, fattening pigs and sows), with the highest rate in fatteners (6.9%, 9/129) and the lowest (1.2%, 2/169) in pre-weaned pigs. Significant differences (P = 0.000) were found among sampling sites but not among age groups (P = 0.084). Sequence analysis indicated that 34 sequence variants, including sequence type A (n = 11) and sequence type B (n = 23), occurred in all age groups. In this study, the existence of sequence type A suggested that B. coli poses a potential threat to human health. More studies are needed to better understand the distributions and public health significance of B. coli in China.

Gastrointestinal Parasites Affecting Non-Human Primates That Are Kept Ex Situ and Their Handlers in Different Brazilian Institutions: Diagnosis and Analysis of Risk Factors

AIM

Determining gastrointestinal parasites' frequency in non-human primates (NHPs) and handlers in different Brazilian institutions, and associate it with management information.

METHODS

Different institutions in São Paulo (A), Brasília (B), Rio de Janeiro (C), Pará (D) and Santa Catarina (E) were included in the study. Fecal samples were processed by using coproparasitological techniques; information about NHP handling and professionals' routine were collected through the use of questionnaires.

RESULTS

In total, 33.1% of 511 NHP samples were positive for parasites; the Entamoebidae Group and Strongyloides sp.-compatible eggs were the most detected protozoa and helminths, respectively. The Entamoebidae Group was mainly diagnosed in Alouatta from Institutions E and D, and was also the only parasite detected in handlers. Strongyloides-compatible eggs were mostly evident in fecal samples collected from Cebidae from Institutions B and D. Some risk factors associated with parasite infection were a high number of animals in the same enclosure and their use for research protocol purposes, whereas quarantine, a post-infection vacant period in enclosures and antiparasitic supply were categorized as protective factors against these agents' infection.

CONCLUSIONS

Parasites showing different transmission routes but concomitantly circulating in NHP institutions located in different Brazilian regions were identified in the current study, with an emphasis on those presenting zoonotic potential.

Protozoan predation as a driver of diversity and virulence in bacterial biofilms

Protozoa are eukaryotic organisms that play a crucial role in nutrient cycling and maintaining balance in the food web. Predation, symbiosis and parasitism are three types of interactions between protozoa and bacteria. However, not all bacterial species are equally susceptible to protozoan predation as many are capable of defending against predation in numerous ways and may even establish either a symbiotic or parasitic life-style. Biofilm formation is one such mechanism by which bacteria can survive predation. Structural and chemical components of biofilms enhance resistance to predation compared to their planktonic counterparts. Predation on biofilms gives rise to phenotypic and genetic heterogeneity in prey that leads to trade-offs in virulence in other eukaryotes. Recent advances, using molecular and genomics techniques, allow us to generate new information about the interactions of protozoa and biofilms of prey bacteria. This review presents the current state of the field on impacts of protozoan predation on biofilms. We provide an overview of newly gathered insights into (i) molecular mechanisms of predation resistance in biofilms, (ii) phenotypic and genetic diversification of prey bacteria, and (iii) evolution of virulence as a consequence of protozoan predation on biofilms.

Uninvited guest, Balantidium coli in urine in a patient with bladder cancer: A case report and review of the literature

Key Clinical Message

In contrast to intestinal balantidiasis, which is widespread throughout the world, urinary balantidiasis is uncommon. It often affects people with underlying diseases, and acute infections may be fatal. Even though urine is not typical for this parasite, specific morphologic characteristics can aid in accurate diagnosis.

Abstract

Balantidium coli is a ciliated protozoan which can infect intestinal system. Urinary balantidiasis is an extremely rare infection that may cause serious issues in patients with underlying diseases. Herein, we present a case of urinary balantidiasis in a patient with bladder cancer.

Comparative Genomic and Transcriptomic Profiling Revealed the Molecular Basis of Starch Promoting the Growth and Proliferation of Balantioides coli

Carbohydrates are the main source of nutrition for B. coli, supplying energy for cell growth and development. The research aimed at investigating the mechanism of starch on the growth and replication of B. coli. Single-cell separation was used to isolate single trophozoites of B. coli under a stereomicroscope, transcriptomic profiling was conducted based on the SMART-seq2 single-cell RNA-seq method. Comparative genomic analysis was performed on B. coli and eight other ciliates to obtain specific and expanded gene families of B. coli. GO and KEGG enrichment analysis were used to analyze the key genes of B. coli under the action of starch in the present study. The results of single-cell RNA-seq depicts starch affected the growth and replication of B. coli in two ways: (1) the cell cycle was positively promoted by the activation of the cAMP/PKA signaling pathway via glycolysis; (2) the cell autophagy was suppressed through the PI3K/AKT/mTOR pathway. Genes involved in endocytosis, carbohydrate utilization, and the cAMP/PKA signaling pathway were highly enriched in both specific and expanded gene families of B. coli. Starch can be ingested and hydrolyzed into glucose, in turn affecting various biological processes of B. coli. The molecular mechanism of the effect of starch on the growth and proliferation of B. coli by promoting cell cycle and inhibiting the autophagy of trophozoites has been elucidated in our study.

Identification of potentially zoonotic parasites in captive orangutans and semi-captive mandrills: Phylogeny and morphological comparison

Cysts and trophozoites of vestibuliferid ciliates and larvae of Strongyloides were found in fecal samples from captive orangutans Pongo pygmaeus and P. abelii from Czech and Slovak zoological gardens. As comparative material, ciliates from semi-captive mandrills Mandrillus sphinx from Gabon were included in the study. Phylogenetic analysis of the detected vestibuliferid ciliates using ITS1-5.8s-rRNA-ITS2 and partial 18S ribosomal deoxyribonucleic acid (rDNA) revealed that the ciliates from orangutans are conspecific with Balantioides coli lineage A, while the ciliates from mandrills clustered with Buxtonella-like ciliates from other primates. Morphological examination of the cysts and trophozoites using light microscopy did not reveal differences robust enough to identify the genera of the ciliates. Phylogenetic analysis of detected L1 larvae of Strongyloides using partial cox1 revealed Strongyloides stercoralis clustering within the cox1 lineage A infecting dogs, humans, and other primates. The sequences of 18S rDNA support these results. As both B. coli and S. stercoralis are zoonotic parasites and the conditions in captive and semi-captive settings may facilitate transmission to humans, prophylactic measures should reflect the findings.

Mother-to-daughter transmission of hygienic anti-parasite behaviour in mandrills

Social animals are particularly exposed to infectious diseases. Pathogen-driven selection pressures have thus favoured the evolution of behavioural adaptations to decrease transmission risk such as the avoidance of contagious individuals. Yet, such strategies deprive individuals of valuable social interactions, generating a cost-benefit trade-off between pathogen avoidance and social opportunities. Recent studies revealed that hosts differ in these behavioural defences, but the determinants driving such inter-individual variation remain understudied. Using 6 years of behavioural and parasite data on a large natural population of mandrills (Mandrillus sphinx), we showed that, when parasite prevalence was high in the population, females avoided grooming their conspecifics' peri-anal region (PAR), where contagious gastro-intestinal parasites accumulate. Females varied, however, in their propensity to avoid this risky body region: across years, some females consistently avoided grooming it, while others did not. Interestingly, hygienic females (i.e. those avoiding the PAR) were less parasitized than non-hygienic females. Finally, age, dominance rank and grooming frequency did not influence a female's hygiene, but both mother-daughter and maternal half-sisters exhibited similar hygienic levels, whereas paternal half-sisters and non-kin dyads did not, suggesting a social transmission of this behaviour. Our study emphasizes that the social inheritance of hygiene may structure behavioural resistance to pathogens in host populations with potential consequences on the dynamics of infectious diseases.

Survey of Zoonotic Diarrheagenic Protist and Hepatitis E Virus in Wild Boar (Sus scrofa) of Portugal

Enteropathogenic parasites and viruses have been frequently reported in swine and can infect a wide range of mammals, including humans. Among the wide variety of parasites infecting swine, diarrhoeagenic protists are among those that cause significant morbidity. Hepatitis E virus (HEV) has also been reported both in domestic pigs and wild boar and is known to have an important public health significance. These agents share the fecal−oral transmission route, but data on their fecal shedding and circulation pathways are still lacking or incomplete. Hence, the aim of the present study was to characterize the presence of microeukaryotes and HEV in the wild boar of Portugal. Wild boar stool samples (n = 144) were obtained during the official hunting seasons (October to February) in 2018/2019, 2019/2020, and 2021/2022 and tested for Cryptosporidium spp., Balantioides coli, Giardia duodenalis, Blastocystis sp., Enterocytozoon bieneusi and HEV by molecular assays, followed by sequencing and phylogenetic analysis. We have detected Cryptosporidium scrofarum (1.4%, 95% CI: 0.2−4.9), B. coli (14.6%, 95% CI: 9.2−21.4), Blastocystis ST5 (29.2%, 95% CI: 21.9−37.2) and HEV genotype 3 (2.8%, 95% CI: 0.7−6.9; subgenotypes 3e and 3m). Co-infections were observed in thirteen animals where two were positive for both HEV and B. coli, one was positive for both C. scrofarum and Blastocystis ST5, and ten were positive for both B. coli and Blastocystis ST5. Giardia duodenalis and E. bieneusi were not detected in the surveyed wild boar population. As far as we know, this is the first report describing protist infections by Cryptosporidium spp., B. coli, and Blastocystis sp., as well as the first identification of the emerging HEV genotype 3m in wild boar of Portugal. The present work shows that potentially zoonotic protozoa and HEV are circulating in wild boar populations in Portugal. Awareness and epidemic-surveillance network implementation measures targeting wild boar are needed to prevent the spread of these pathogenic agents to humans.

Enteric protozoal infections in camels: Etiology, epidemiology, and future perspectives

Camels have great potential as a safety valve for current and future food security for pastoralists, agropastoralists, and urban populations. Enteric protozoal diseases are important causes of economic losses in camels; however, they are poorly concerned globally. The most common members of enteric protozoa are Balantidium, Eimeria, Giardia, and Cryptosporidium. Some of them threaten human health as humans can be infected by consuming food or water contaminated with camel feces, particularly in poor communities with inadequate sanitation and low-quality healthcare facilities. For these reasons, a comprehensive and careful investigation was conducted on some enteric protozoal diseases of camels to present an updated insight into the etiology, epidemiology, and future trends in diagnosing and controlling camel enteric protozoa. Future studies on the camel enteric protozoa should be carried out to develop advanced diagnostic approaches in diverse farm animal species. Moreover, the protozoan zoonotic potential should be considered to secure human health.

Commensal Intestinal Protozoa-Underestimated Members of the Gut Microbial Community

The human gastrointestinal microbiota contains a diverse consortium of microbes, including bacteria, protozoa, viruses, and fungi. Through millennia of co-evolution, the host-microbiota interactions have shaped the immune system to both tolerate and maintain the symbiotic relationship with commensal microbiota, while exerting protective responses against invading pathogens. Microbiome research is dominated by studies describing the impact of prokaryotic bacteria on gut immunity with a limited understanding of their relationship with other integral microbiota constituents. However, converging evidence shows that eukaryotic organisms, such as commensal protozoa, can play an important role in modulating intestinal immune responses as well as influencing the overall health of the host. The presence of several protozoa species has recently been shown to be a common occurrence in healthy populations worldwide, suggesting that many of these are commensals rather than invading pathogens. This review aims to discuss the most recent, conflicting findings regarding the role of intestinal protozoa in gut homeostasis, interactions between intestinal protozoa and the bacterial microbiota, as well as potential immunological consequences of protozoa colonization.

Balantioides coli Fecal Excretion in Hunted Wild Cervids (Cervus elaphus and Dama dama) from Portugal

Balantioides coli is a zoonotic enteric protozoan parasite of public veterinary health relevance and a concern in animal production and food safety. While wild cervids are recognized reservoirs for several zoonotic pathogens, little is known about the occurrence of B. coli in deer species, especially in Europe. To fill this gap, a total of 130 fecal samples from legally hunted red deer (Cervus elaphus, n = 95) and fallow deer (Dama dama, n = 35) were passively collected during two hunting seasons (October to February; 2018-2019 and 2019-2020) in Portugal. After assessment by PCR assay targeting the complete ITS1-5.8s-rRNA-ITS2 region and the 3' end of the ssu-rRNA gene of the parasite, a prevalence of 4.2% (4/95, 95% CI: 0.2-8.3) in red deer and of 5.7% (2/35, 95% CI: 0.0-13.4) in fallow deer was found. Sequence and phylogenetic analyses allowed the identification of B. coli genetic variants A (in two red deer) and B (in two red deer and two fallow deer). This is the first molecular-based description of B. coli in European deer species, whose population have increased in density and geographical range in recent years. Continued monitoring of wild ungulates as potential vectors of parasitic infection diseases of zoonotic nature is crucial to safeguard public health and food safety.

Family-Run Pig Farms: Research and Extension Activities for Parasite Control in a Municipality in the State of Rio de Janeiro, Brazil

The parasites infesting pigs and pig farmers on family farms in Rio de Janeiro city, Brazil, were analyzed, and extension activities were carried out to impart information about parasites. Between 2020 and 2021, fecal samples were collected from 180 pigs as well as ear scrapings from 142 pigs. In addition, 34 stool specimens from farmers and their families were analyzed. The collected material was processed by parasitological techniques. Parasites were detected in 86.1% of the pigs, forms of phylum Ciliophora (70.5%), strongylids (56.7%), Strongyloides ransomi (44.4%), coccidia (38.3%) and Ascaris suum (32.2%). Sarcoptes scabiei var. suis were identified in 3.5% of the pigs. An analysis of infections by age group revealed that the general frequency of phylum Ciliophora and strongylid parasites was statistically significant. Other factors also associated with the frequency of the parasites included the type of food fed to the pigs, cleaning of the facilities, care of piglets and type of facility. The frequency of intestinal parasites of farmers themselves was low; however, the high rate of parasite infections detected in pigs highlighted the precarious conditions of hygiene of the farms. Lastly, the farmers’ participation in extension activities was a step forward in actions to improve their farm management.

PARASITES OF THE BRAZILIAN ROCK CAVY, KERODON RUPESTRIS: REVEALING THEIR HISTORY IN THE BRAZILIAN SEMIARID REGION

Using microscopy and/or immunodiagnosis, the authors analyzed 284 fecal samples from the Brazilian rock cavy, Kerodon rupestris, that were collected between 1984 and 2015 in Serra da Capivara National Park for the presence of helminths and protozoa. Fourteen morphospecies of helminth eggs of the following taxa were found: Trematoda, Nematoda, Strongylidae, Lagochilascaris sp., Strongylida, Trichuris (2 species), Oxyuridae (3 species), Ancylostomatidae (2 species), and Ascarididae (2 species), along with 3 protozoan taxa: Coccidia, Cryptosporidium sp., and Balantidium sp. During the last 30 yr, the population of K. rupestris has increased in the region as a consequence of the creation and management of the National Park, and data from this study show a concurrent increase in the diversity of intestinal parasites in this host, including new reports. Some of these species have zoonotic potential, which suggests that K. rupestris may be in contact with domestic farm animals and/or human feces. These results show the importance of integrating different diagnostic approaches for the identification of protozoa in the region and indicate that further methods need to be employed to increase recovery. This work highlights the usefulness of parasite studies in assessing the health of ecosystems, especially in protected areas, which should be considered by park managers and health agencies.

Prevalencia de Dientamoeba fragilis y otros protozoarios intestinales en porcinos de una granja en la región Andina de Colombia

Dientamoeba fragilis es un protozoario que parasita el intestino grueso del hombre y animales domésticos. Hasta el momento, aún no son claros aspectos de su ciclo de vida, como el rango de hospedadores, reservorios, mecanismo de infección, entre otros. Se postula que el cerdo es un hospedador natural para este protozoario y que, debido a su cercanía con el humano, podría facilitar una transmisión zoonótica. En Colombia no existen a la fecha estudios sobre la presencia de D. fragilis en hospedadores animales, incluidos los cerdos, y los datos sobre la prevalencia de otros protozoarios intestinales en estos animales son escasos. El objetivo fue determinar la frecuencia de protozoarios intestinales, incluyendo D. fragilis, en cerdos de una granja tecnificada de una zona rural de Medellín (región Andina de Colombia). Se recolectaron muestras de materia fecal de 70 cerdos en etapa de preceba, que fueron evaluadas mediante examen directo, tinción tricrómica y Ziehl-Neelsen modificado. Se realizaron análisis univariados con medidas de frecuencia relativa y tendencia central y análisis bivariados para la exploración de factores de riesgo. Se detectó la presencia de D. fragilis en un 13% de las muestras y de otros parásitos como Entamoeba spp. (66%), Blastocystis spp. (64%), Balantioides coli (36%), Cryptosporidium spp. (36%), Iodamoeba butschlii (17%), coccidias (4%) y Giardia spp. (1,4%). En este primer reporte de D. fragilis en cerdos en Colombia se observó la alta prevalencia de otros protozoarios patógenos, lo que corrobora el papel de los cerdos como importantes reservorios de infecciones humanas.

Neglected Case of Human Balantidiasis: Presumed as Antibiotic-Associated Diarrhoea

Background

Balantidiasis, due to its rare human incidence and nonspecific clinical presentations often neglected from the diagnosis considerations; however, a potent pathogen. Herein, we report a case of neglected balantidiasis presumed as antibiotic-associated diarrhoea. Case Presentation. A 27-year-old policeman presented in Sindhuli Hospital, with a chief complaint of epigastric pain, nausea, decreased appetite for several days, and loose stools (3-4 episodes per day). Previously, he was under antibiotic therapy (amoxycillin) for tonsillitis. The health post clinician made a presumptive diagnosis as the side effects of the antibiotics; however, the symptoms were not resolved. Complete blood cell count (CBC) was normal; renal function test (RFT) and liver function (LFT) were within the normal ranges. Ultrasonography of the abdomen and ECG (electrocardiogram) showed normal findings. However, on routine stool actively motile trophozoites of Balantidium coli (B. coli) were seen. He was treated successfully with metronidazole 750 mg tabs orally three times daily for 5 days.

Conclusion

Protozoal infections, like balantidiasis, might be excluded from the diagnostic consideration in antibiotic-associated diarrhoea cases. Therefore, meticulous review of nonspecific clinical presentation and validation of an etiology with support of diagnostic tests are mandatory.

Balantidium coli; Rare and Accidental Finding in the Urine of Pregnant Woman: Case Report

Background

Balantidium coli is a ciliated protozoan parasite, which causes intestinal and extraintestinal infections in humans. It is transmitted feco-orally by ingesting infective cysts with food and water. Urinary balantidiasis may occur through contamination (direct spread from the anal area), secondarily to rectovaginal fistula and following immune suppression. Data about cases of urinary balantidiasis are rare in the world. Currently, there are no documented reports of urinary balantidiasis in Ethiopia. As our understanding, there are only eleven documented reports of urinary balantidiasis globally. However, cases of urinary balantidiasis among pregnant women have not been documented yet. The aim of this report is to alarm health professionals for considering the occurrence of such rare cases and conduct diagnosis.

Case Presentation

A 24-year old pregnant woman was admitted due to severe preeclampsia and preterm delivery at Debre Tabor Comprehensive Specialized Hospital, gynecology ward. Her urine was presented to inpatient laboratory for routine urinalysis. We detected unusual and ciliated parasite from her urine sediment characterized by its active and rotary motility through its cilia and possessing macro- and micro-nuclei, several food vacuoles and ingested red blood cells inside the cytoplasm. Hematuria, many white blood cells and epithelial cells were also detected from the urine sediment, which suggests genito-urinary tract infection due to this parasite. This rare parasite finding was confirmed to be B. coli.

Conclusion

The route of transmission and extraintestinal existence from this woman’s urine was unclear. It might be due to feco-oral transmission and spread to the genitourinary tract through direct anal contact. Moreover, it might be associated with immune suppression as she is pregnant woman.

ATP synthase FOF1 structure, function, and structure-based drug design

ATP synthases are unique rotatory molecular machines that supply biochemical reactions with adenosine triphosphate (ATP)-the universal "currency", which cells use for synthesis of vital molecules and sustaining life. ATP synthases of F-type (FOF1) are found embedded in bacterial cellular membrane, in thylakoid membranes of chloroplasts, and in mitochondrial inner membranes in eukaryotes. The main functions of ATP synthases are control of the ATP synthesis and transmembrane potential. Although the key subunits of the enzyme remain highly conserved, subunit composition and structural organization of ATP synthases and their assemblies are significantly different. In addition, there are hypotheses that the enzyme might be involved in the formation of the mitochondrial permeability transition pore and play a role in regulation of the cell death processes. Dysfunctions of this enzyme lead to numerous severe disorders with high fatality levels. In our review, we focus on FOF1-structure-based approach towards development of new therapies by using FOF1 structural features inherited by the representatives of this enzyme family from different taxonomy groups. We analyzed and systematized the most relevant information about the structural organization of FOF1 to discuss how this approach might help in the development of new therapies targeting ATP synthases and design tools for cellular bioenergetics control.

Phylogenetics and Pathogenicity of Balantioides coli Isolates in Vietnamese Weaned Pigs

PURPOSE

This study aimed to investigate the diversity of Balantioides coli (B. coli) based on the 18S rDNA of isolates collected from weaned pigs with diarrhea and then select a B. coli isolate to determine its pathogenicity in weaned pigs through experimental infection.

METHODS

The genetic analysis of field-isolated B. coli strains was based on sequencing of the partial 18S rDNA genetic fragment and the pathogenicity of an isolate of B. coli (DN2018-2-DTD) was identified through an experimental infection.

RESULTS

The fourteen B. coli isolates shared 98.47-100% nucleotide similarity and were divided into two clades in a phylogenetic tree. In an infection experiment, a slight increase in the body temperature was identified in two infected groups as compared to that in the control group (P < 0.05) from days post-infection (dpi) 12-18 and from dpi 20-27. In the group infected with 3000 CPG/TPG, 2/9 pigs started to develop diarrhea on day two. In the group infected with 500 CPG/TPG, 8/9 pigs had diarrhea on dpi 3. Trophozoites/cysts of B. coli were firstly detected in feces on dpi 3 in a group of pigs infected with a dose of 3000 CPG/TPG, and CPG/TPG reached its peak at dpi 5 in both groups of infected pigs (35,450 and 13,250 CPG/TPG). There was a significant difference in the bodyweight of the control group (noninfected) as compared to that of the groups of infected pigs on dpi 7 (P < 0.05), 14 (P < 0.001) and 28 (P < 0.01). Lesions were solely recorded in infected pigs, including white ulcerative nodules with necrosis scattered in the mucosa of the colon and cecum on dpi 7, 14, and 28.

CONCLUSION

This is the first study to investigate the pathogenicity of B. coli in Vietnamese pigs to demonstrate that B. coli could induce necrotic ulcerative enteritis and diarrhea in weaned pigs.

Association of human disturbance and gastrointestinal parasite infection of yellow baboons in western Tanzania

Human disturbance is an ongoing threat to many wildlife species, manifesting as habitat destruction, resource overuse, or increased disease exposure, among others. With increasing human: non-human primate (NHP) encounters, NHPs are increasingly susceptible to human-introduced diseases, including those with parasitic origins. As such, epidemiology of parasitic disease is becoming an important consideration for NHP conservation strategies. To investigate the relationship between parasite infections and human disturbance we studied yellow baboons (Papio cynocephalus) living outside of national park boundaries in western Tanzania, collecting 135 fresh faecal samples from nine troops occupying areas with varying levels of human disturbance. We fixed all samples in 10% formalin and later evaluated parasite prevalence and abundance (of isotrichid ciliates and Strongylida). We identified seven protozoan and four helminth taxa. Taxa showed varied relationships with human disturbance, baboon troop size and host age. In four taxa, we found a positive association between prevalence and troop size. We also report a trend towards higher parasite prevalence of two taxa in less disturbed areas. To the contrary, high levels of human disturbance predicted increased abundance of isotrichid ciliates, although no relationship was found between disturbance and Strongylida abundance. Our results provide mixed evidence that human disturbance is associated with NHP parasite infections, highlighting the need to consider monitoring parasite infections when developing NHP conservation strategies.

An annotated checklist of the eukaryotic parasites of humans, exclusive of fungi and algae

The classification of "parasites" in the medical field is a challenging notion, a group which historically has included all eukaryotes exclusive of fungi that invade and derive resources from the human host. Since antiquity, humans have been identifying and documenting parasitic infections, and this collective catalog of parasitic agents has expanded considerably with technology. As our understanding of species boundaries and the use of molecular tools has evolved, so has our concept of the taxonomy of human parasites. Consequently, new species have been recognized while others have been relegated to synonyms. On the other hand, the decline of expertise in classical parasitology and limited curricula have led to a loss of awareness of many rarely encountered species. Here, we provide a comprehensive checklist of all reported eukaryotic organisms (excluding fungi and allied taxa) parasitizing humans resulting in 274 genus-group taxa and 848 species-group taxa. For each species, or genus where indicated, a concise summary of geographic distribution, natural hosts, route of transmission and site within human host, and vectored pathogens are presented. Ubiquitous, human-adapted species as well as very rare, incidental zoonotic organisms are discussed in this annotated checklist. We also provide a list of 79 excluded genera and species that have been previously reported as human parasites but are not believed to be true human parasites or represent misidentifications or taxonomic changes.

Diarrhoea-causing enteric protist species in intensively and extensively raised pigs (Sus scrofa domesticus) in Southern Spain. Part I: Prevalence and genetic diversity

Numerous protist species are shared between humans and pigs. Among those, Giardia duodenalis, Cryptosporidium spp. and Balantioides coli have a clear public and animal health significance. For others such as Enterocytozoon bieneusi and Blastocystis sp., their impact on animal health has not been fully established. Little information is currently available on the molecular diversity of these protists in swine populations. To fill this gap, we molecularly assessed G. duodenalis, Cryptosporidium spp., B. coli, Blastocystis sp. and E. bieneusi in faecal samples from Iberian and Large White pigs raised under different (intensive and/or extensive) management systems in southern Spain. A total of 151 extensively raised Iberian pigs, 140 intensively raised Iberian pigs, and 184 intensively raised Large White pigs were investigated. Blastocystis sp. was the agent most prevalently found (47.8%), followed by B. coli (45.5%), G. duodenalis (10.7%), E. bieneusi (6.9%), and Cryptosporidium spp. (5.5%). Blastocystis sp. was significantly less prevalent in intensively raised Iberian pigs (22.9%) than in their extensively raised counterparts (51.0%) or in intensively raised Large White pigs (64.1%). A significantly higher prevalence was found for G. duodenalis, Cryptosporidium spp., and E. bieneusi in Large White pigs than Iberian pigs. Balantioides coli was similarly distributed (40.0-51.1%) in all three investigated swine populations. Sequence analyses revealed the presence of G. duodenalis assemblage E, two Cryptosporidium species (Cryptosporidium scrofarum and Cryptosporidium suis), B. coli (genotypes A and B), Blastocystis sp. (ST1, ST3, and ST5), and E. bieneusi (EbpA, EbpC, EbpD, O, and a novel genotype named PigSpEb2). Novel genotype PigSpEb2 was found alone or in combination with EbpA. Data suggest a widespread exposure to protist enteroparasites in domestic pig populations irrespectively of breed and raising management system. Many of the species/genotypes identified have a zoonotic potential and might represent a public health concern.

Balantidiasis in humans: A systematic review and meta-analysis

Balantioides coli is a protozoan that infects different hosts species, including humans, with zoonotic transmission. The parasite, which lives in the large intestine and in other organs, can lead to serious infections that may culminate in death. Information about human balantidiasis is generally still very scanty. In view of the above, the purpose of this study was to analyze the epidemiological, clinical and laboratory characteristics of human balantidiasis based on a systematic review and meta-analysis. The scientific articles were retrieved from various databases and were subjected to descriptive analyses, chi-squared tests, and summarized on a forest plot and the heterogeneity index (I²). A total of 103 articles were eligible and included in this review. Out of these 103 articles, 75 were clinical case reports and 28 were epidemiological studies, indicating a frequency of 997 (3.98%) people potentially infected with B. coli. The publication dates of the analyzed articles ranged from 1910 to 2020, but the majority (68.9%) were published between 1998 and 2020. A considerable number of these articles were published in South America and Asia, mostly in Brazil and India, respectively. However, in Africa, Ethiopia, was observed the higher number of infected people (47.5%). A significant association (p < 0.05) was identified between proximity to pigs and positivity for B. coli, since more than 16% infected people were in proximity with pigs and/or their excreta. Infection by the protozoan was classified mainly as intestinal, and the predominant symptom was dysentery. Extraintestinal infections were found in 27 individuals, with colonization of the genitourinary tract frequently highlighted. Direct examination (17.2%), followed by an association of direct examination and sedimentation (45.7%), were the most commonly performed parasitological techniques, and the most frequently diagnosed form was trophozoites, corresponding to 22.5% of cases. The most common treatment for parasitized individuals (11.8%) was an association of tetracycline drugs with nitroimidazole derivatives. The articles retrieved, mainly epidemiological ones, used in meta-analysis showed high heterogeneity (I²> 50%, p < 0.05), impairing the retrieval and comparison of results. Some articles were found to provide incomplete information, making it difficult to retrieve and analyze variables. However, this review enabled us to compile and restate factors that appear to be associated with cases of human balantidiasis.

Balantidium coli in pig farms suspected of porcine circovirus type 2 (PCV2) associated enteritis

Introduction

Diarrhoea in growing-finishing pigs is a common problem of commercial pig farms. Among many causative factors, porcine circovirus type 2 (PCV2) is one considered an important pathogen in modern pig production. The aim of the study was to verify if PCV2 was responsible for antibiotic non-responsive diarrhoea and wasting in pigs.

Material and Methods

A total of 13 dead pigs aged between 12 and 15 weeks from three Polish farms with persistent herd symptoms suggestive of PCV2 infection were provided for evaluation. Sections of lymph nodes and intestines were analysed by in situ hybridization (ISH) for PCV2 and histopathological examination. Faeces and intestinal scrapings were tested for Lawsonia intracellularis and Brachyspira hyodysenteriae by real-time PCR and for parasitic infection by flotation and decantation.

Results

ISH and histopathological examination showed that all pigs were PCV2 systemic disease negative. Swine dysentery was confirmed by real-time PCR on two farms, and proliferative enteropathy on one farm. In histological examinations, erosions of the caecal and colonic mucosa were found, together with cysts and trophozoites of Balantidium coli. The protozoa were present in the intestinal lumen and mucosa. B. coli cysts were identified in faeces from all examined pigs.

Conclusion

These results suggest that monitoring of B. coli infections should be an additional measure of control and prevention of gastrointestinal tract disorders in modern swine husbandry.

Prevalence and risk factors of human Balantidium coli infection and its association with haematological and biochemical parameters in Ga West Municipality, Ghana

Background

In Ghana, Balantidium coli (B. coli) has been identified in vegetables and in pigs, although there is a paucity of data regarding human balantidiosis. This study sought to assess human B. coli infection in Ghana, factors associated with the infection as well as its association with haematological and biochemical parameters.

Methods

Two pig rearing communities in the Ga West Municipality, Ghana, were involved in this study. Stool and blood samples were collected from pig farmers and their exposed household members as well as relevant information on potential associated factors. Eosin-saline wet preparation was done on the same day of stool samples were collected while formol ether concentration technique was performed later. Haematological, biochemical parameters and serum electrolytes were determined using Celltac MEK-6500 K, PKL-125 biochemical analyser, and FT-320 electrolyte analyser, respectively.

Results

The overall prevalence of balantidiosis was 10.4 %, significantly higher among farmers (21.7 %) than in exposed household members (5.8 %) (x² = 17.8, p = 0.000025). Of the 43 infected individuals, 20.9 % were co-infected with either Entamoeba histolytica, Giardia lamblia, or Schistosoma mansoni. In B. coli infection, mild to moderate anaemia together with a reduction in levels of platelet, albumin and, sodium, chloride, and bicarbonate ions were observed. However, white blood cells were significantly elevated in infected states. Poor farming practices such as free-range systems, improper disposal of pig faeces, lack of use of protective farming clothing, and unavailability of dedicated farming clothing were found to be associated with B. coli infection status. Finally, frequent diarrhea (OR = 12.30, p = 0.006) with occult blood (OR = 25.94, p < 0.0001) were found to be predictors of B. coli infection.

Conclusions

Human balantidiosis is endemic in Ga West Municipality, Ghana. Individuals living closed to pig rearing communities presenting with frequent diarrhea with occult blood in stool should be screened and treated for balantidiosis to mitigate the clinical consequences of the infection.

Identification of Zoonotic Balantioides coli in Pigs by Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) and Its Distribution in Korea

Balantioides coli is a zoonotic protozoan parasite whose main reservoir is pigs. Recent studies have shown that B. coli variant A but not B has zoonotic potential. While B. coli infection has been reported in different animals and countries, the prevalence of the zoonotic variant is limited due to a lack of molecular information. Therefore, this study investigated the prevalence of B. coli in domestic pigs in Korea and assessed its zoonotic potential. A total of 188 pig fecal samples were collected from slaughterhouses in Korea. B. coli was identified by microscopy and molecular methods. B. coli was identified in 79 (42.9%) and 174 (94.6%) samples by microscopy and polymerase chain reaction (PCR), respectively. This study also developed a PCR-restriction fragment length polymorphism (PCR-RFLP) method to differentiate B. coli variant A from B without sequence analysis. Using this method, 62 (33.7%) and 160 (87.0%) samples were positive for variants A and B, respectively, and 48 (26.1%) samples were co-infected with both variants. Sequence and phylogenetic analyses showed a high genetic diversity of B. coli in pigs in Korea. To our knowledge, this is the first study to develop a method to differentiate B. coli variants A and B without sequence analysis and to assess the molecular epidemiology of B. coli in pigs. Continuous monitoring of zoonotic B. coli in pigs should be performed as pigs are the main source of human balantidiasis.

Parasites Circulating in Wild Synanthropic Capybaras (Hydrochoerus hydrochaeris): A One Health Approach

Capybaras (Hydrochoerus hydrochaeris) are affected by a wide range of protozoan and metazoan-derived parasitic diseases. Among parasites of free-ranging capybaras are soil-, water-, food- and gastropod-borne parasitosis, today considered as opportunistic infections in semiaquatic ecosystems. The overlapping of the capybara’s natural ecological habitats with human and domestic animal activities has unfortunately increased in recent decades, thereby enhancing possible cross- or spillover events of zoonotic parasites. Due to this, three synanthropic wild capybara populations in the Orinoco Basin were studied for the occurrence of gastrointestinal parasite infections. A total of forty-six fecal samples were collected from free-ranging capybaras in close proximity to livestock farms. Macroscopical analyses, standard copromicroscopical techniques, coproELISA, PCR, and phylogenetic analysis revealed thirteen parasite taxa. In detail, the study indicates stages of five protozoans, four nematodes, one cestode, and three trematodes. Two zoonotic parasites were identified (i.e., Plagorchis muris, and Neobalantidium coli). The trematode P. muris represents the first report within South America. In addition, this report expands the geographical distribution range of echinocoelosis (Echinocoleus hydrochoeri). Overall, parasitological findings include two new host records (i.e., P. muris, and Entamoeba). The present findings collectively constitute baseline data for future monitoring of wildlife-derived anthropozoonotic parasites and call for future research on the health and the ecological impact of this largest semiaquatic rodent closely linked to humans, domestic and wild animals.

Occurrence of Intestinal Parasites of Public Health Significance in Fresh Horticultural Products Sold in Maputo Markets and Supermarkets, Mozambique

(1) Background: Giardia duodenalis and Cryptosporidium are important neglected parasites associated with diarrhea, such as the emerging Enterocytozoon bieneusi. All three are foodborne parasites raising concerns in public health. This study intended to understand the intestinal parasite occurrence with emphasis on G. duodenalis, Cryptosporidium, and E. bieneusi in fresh fruits/vegetables sold in the main municipal markets of Maputo city, Mozambique. (2) Methods: A total of 321 fresh horticultural products were purchased in the rainy and dry seasons (five markets/two supermarkets/one agricultural zone). Light microscopy (LM) and PCR analysis were performed. (3) Results: By LM and/or PCR, 29.3% of the samples presented at least one parasite (rainy season: 22.9%; dry season: 35.1%). The most contaminated horticultural products: collected in dry season, from Zimpeto and Fajardo markets, lettuce and pointed white cabbage. Overall, 3.7% of G. duodenalis, 1.3% of E. bieneusi, and other intestinal parasites (pathogenic and non-pathogenic) were identified. (4) Conclusions: Important pathogenic intestinal parasites were identified in fruits/vegetables commercially purchased in Maputo City. This fact must be taken into consideration when planning the management of these horticultural markets, in order to reduce the risk of contamination of fresh produce by intestinal parasites, and to prevent foodborne diseases.

Parasitic Intestinal Protists of Zoonotic Relevance Detected in Pigs by Metabarcoding and Real-Time PCR

Several parasite species are shared between humans and pigs. We explored the application of next-generation sequencing-based metabarcoding supplemented with real-time PCR to fecal DNAs from 259 samples from 116 pigs in Denmark to detect and differentiate single-celled intestinal parasites of zoonotic relevance. Enterocytozoon bieneusi, Balantioides coli, and Giardia duodenalis were observed in 34/37 (92%), 148/259 (57%), and 86/259 (33%) samples, respectively. Entamoeba polecki ST1, E. polecki ST3, and Entamoeba hartmanni were detected in 104/259 (40%), 161/259 (62%), and 8/259 (3%) samples, respectively. Metabarcoding and real-time PCR detected Cryptosporidium in 90/259 (35%) and 239/259 (92%) of the samples, respectively, with Cryptosporidium suis and Cryptosporidium scrofarum observed in nearly equal proportions. Blastocystis subtypes 1, 3, 5, and 15 were found in 72 (28%), 6 (2%), 176 (68%), and 36 (14%) of 259 samples, respectively. Iodamoeba was identified in 1/259 samples (<1%), while none of 37 tested samples was positive for Dientamoeba fragilis. Our results illustrate how metabarcoding exemplifies a 'one-fits-many' approach to detecting intestinal single-celled parasites in feces supplemented with real-time PCR for selected parasites. Using metabarcoding with pathogen-specific assays may help detect emerging and previously underdetected pathogens and further elucidate the role of micro-eukaryotic parasites in human and animal health and disease.

Avoidance of Contaminated Food Correlates With Low Protozoan Infection in Bonobos

Intense selection pressure from parasites on free-living animals has resulted in behavioral adaptations that help potential hosts avoid sources of infection. In primates, such “behavioral immunity” is expressed in different contexts and may vary according to the ecology of the host, the nature of the infectious agent, and the individual itself. In this study, we investigated whether avoidance of contaminated food was associated with reduced parasite infection in sanctuary-housed bonobos. To do this, we used bonobos’ responses to soil- and fecally-contaminated food in behavioral experiments, and then compared the results with an estimate of protozoan infection across individuals. We found that avoidance of contaminated food correlated negatively with Balantioides coli infection, a potentially pathogenic protozoan transmitted through the fecal-oral route. The association between avoidance responses and parasitism were most evident in experiments in which subjects were offered a choice of food items falling along a gradient of fecal contamination. In the case of experiments with more limited options and a high degree of contamination, most subjects were averse to the presented food item and this may have mitigated any relationship between feeding decisions and infection. In experiments with low perceived levels of contamination, most subjects consumed previously contaminated food items, which may also have obscured such a relationship. The behavioral immunity observed may be a consequence of the direct effects of parasites (infection), reflecting the first scale of a landscape of disgust: individual responses. Indirect effects of parasites, such as modulation of feeding decisions and reduced social interactions—and their potential trade-offs with physiological immunity—are also discussed in light of individual fitness and primate evolution. This study builds on previous work by showing that avoidance behaviors may be effective in limiting exposure to a wide diversity of oro-fecally transmitted parasites.

Gastrointestinal parasites of indigenous pigs (Sus domesticus) in south-central Nepal

BACKGROUND

Intestinal parasites have a significant impact on productivity of pigs. Additionally, presence of zoonotic parasites in pig faeces used as fertilizer and ingestion of raw or undercooked pork products originated from parasite-infested pigs pose a risk to human health.

OBJECTIVES

The aim of the study was to estimate the prevalence and diversity of gastrointestinal (GI) parasites in indigenous pigs (Sus domesticus) maintained under traditional rearing system in Nepal.

METHODS

Fresh faecal samples (n = 100) were collected from the pigs of varying age and sex maintained in 18 small-scale farms in south-central Nepal. Samples were processed using various standard methods and examined for parasite eggs, cysts or oocysts.

RESULTS

Prevalence of GI parasites in indigenous pigs was 91%, comprising of 14 different genera of protozoans and helminths. Male pigs generally had a higher (97.5%) prevalence of GI parasites than females (87%). While 90% of the suckling and weaner piglets were positive for the GI parasites, all growers and 85% the adult pigs were infected with the parasites. Entamoeba spp. were the primary protozoans in all age groups. Strongyloides sp. was more prevalent helminths in suckling and weaner piglets, whereas Ascarid spp. were higher in both growers and adults. Triplet infection was higher (33.3%) in suckling and weaner piglets, while quadruplet and pentuplet infections were higher (p < .05) among growers (46.7%) and adults (30%), respectively.

CONCLUSIONS

The indigenous pigs harbour a higher prevalence and greater diversity of GI parasites. GI parasitism varies by sex and age of the pigs.

Macroevolutionary analyses of ciliates associated with hosts support high diversification rates

Ciliophora is a phylum that is comprised of extremely diverse microorganisms with regard to their morphology and ecology. They may be found in various environments, as free-living organisms or associated with metazoans. Such associations range from relationships with low metabolic dependence such as epibiosis, to more intimate relationships such as mutualism and parasitism. We know that symbiotic relationships occur along the whole phylogeny of the group, however, little is known about their evolution. Theoretical studies show that there are two routes for the development of parasitism, yet few authors have investigated the evolution of these characteristics using molecular tools. In the present study, we inferred a wide dated molecular phylogeny, based on the 18S rDNA gene, for the entire Ciliophora phylum, mapped life habits throughout the evolutionary time, and evaluated whether symbiotic relationships were linked to the variation in diversification rates and to the mode of evolution of ciliates. Our results showed that the last common ancestor for Ciliophora was likely a free-living organism, and that parasitism is a recent adaptation in ciliates, emerging more than once and independently via two distinct routes: (i) a free-living ciliate evolved into a mutualistic organism and, later, into a parasitic organism, and (ii) a free-living ciliate evolved directly into a parasitic organism. Furthermore, we have found a significant increase in the diversification rate of parasitic and mutualistic ciliates compared with their free-living conspecifics. The evolutionary success in different lineages of symbiont ciliates may be associated with many factors including type and colonization placement on their host, as well as physical and physiological conditions made available by the hosts.

Prevalence of Balantidium coli (Malmsten, 1857) infection in swine reared in South Italy: A widespread neglected zoonosis

Background and Aim:

Balantidiasis, caused by Balantidium coli (syn. Neobalantidium coli or B. coli), represents a neglected parasitic infection of zoonotic significance affecting a variety of hosts, including domestic pigs that are the main reservoir. B. coli has a direct life cycle with a fecal-oral route transmission that occurs mainly by the ingestion of food and water contaminated with cysts. The ingestion of meat contaminated during inappropriate slaughtering processes may represent a new potential route of transmission. Only a few studies have investigated the prevalence of B. coli in domestic pigs in Italy, despite its high prevalence and zoonotic significance. This study aimed to improve the knowledge on B. coli prevalence in domestic swine reared both in intensive and “en plein air” breeding systems in the south of Italy.

Materials and Methods:

The infection rate of B. coli in pigs bred in 15 different pig farms and regularly slaughtered in South Italy, in the Calabria region, was investigated. From 2017 to 2019, 177 terminal parts of the rectums of pigs, of which 91 commercial hybrids and 86 autochthonous (Nero Calabrese), reared, respectively, in intensive and “en plein air” breeding system, were tested for parasite detection. After the slaughtering, the terminal part of the rectum was sampled and transported to the laboratories and immediately processed. For the detection of trophozoites, fresh smears of feces were examined at light microscopy. Moreover, flotation was performed using a sodium chloride solution, then smears of feces were dispersed on microscope slides and examined at light microscopy. The observed parasites were identified at the species level using morphological characteristics.

Results:

B. coli was detected in a total of 83 (i.e., 46.89%) pigs, with a significantly higher prevalence (p<0.0001) found in commercial hybrid (i.e., 59/91-64.84%) pigs rather than in autochthonous ones (i.e., 24/86-27.91%). It follows that the infection was more common in pigs reared in the intensive breeding system than in “en plein air” ones (p<0.0001). The infection prevalence was higher in males than in females and lower in elder animals than in younger ones (p=0.012 and p<0.0001, respectively).

Conclusion:

The breeding system is likely the main discriminant for the parasite spread as well as the hygienic condition of the farms. Good manufacturing and hygiene practices along the food production chain are crucial in preventing human balantidiasis transmission by meat consumption. The high B. coli prevalence, the wide spectrum of host species, and its zoonotic significance push toward a greater public interest.

Comparison between five coprological methods for the diagnosis of Balantidium coli cysts in fecal samples from pigs

Background and Aim:

Balantidium coli is a protozoan that can infect humans and non-human primates, being the domestic pigs the animals most affected by this parasite. This study aimed to compare the performance of five coprological methods for diagnosis of Balantidium coli cysts in fecal samples from pigs.

Materials and Methods:

From September to December 2019, 558 fecal samples were collected from the rectum of backyard pigs in the Bucaramanga metropolitan area, Colombia. The average age of the sampled animals was 3-4 months. Fecal samples collected were tested using the following coprological techniques: Direct examination with Lugol’s iodine solution, buffered saline, centrifugation/flotation and McMaster techniques, and Ziehl–Neelsen method.

Results:

The results indicate that B. coli cysts were diagnosed most frequently through direct examination with Lugol’s iodine solution (52.7% of the samples) followed by direct examination with a buffered saline solution (37.6%). Moderate concordance (k=0.41; p<0.05) was determined between direct method with Lugol’s iodine and buffered saline solution, McMaster and buffered saline (k=0.35; p<0.05), and centrifugation/flotation and buffered saline (k=0.28; p<0.05) showed a fair degree of concordance. The rest of the comparisons were classified as poor. The flotation techniques (centrifugation/flotation and McMaster) did not show good recovery of cysts.

Conclusion:

It is concluded that the most efficient method for diagnosing this parasitosis was to an association between direct examination with Lugol’s iodine solution and buffered saline.

Research Relevant Background Lesions and Conditions: Ferrets, Dogs, Swine, Sheep, and Goats

Animal models provide a valuable tool and resource for biomedical researchers as they investigate biological processes, disease pathogenesis, novel therapies, and toxicologic studies. Interpretation of animal model data requires knowledge not only of the processes/diseases being studied but also awareness of spontaneous conditions and background lesions in the model that can influence or even confound the study results. Species, breed/stock, sex, age, anatomy, physiology, diseases (noninfectious and infectious), and neoplastic processes are model features that can impact the results as well as study interpretation. Here, we review these features in several common laboratory animal species, including ferret, dog (beagle), pig, sheep, and goats.

A survey for potentially zoonotic parasites in backyard pigs in the Bucaramanga metropolitan area, Northeast Colombia

Background and Aim:

Backyard pigs farming is a rearing system associated with poor hygienic and sanitary conditions of the pig, often causing public health and food safety problems. Therefore, this study was conducted to investigate the occurrence of potentially zoonotic parasites in population pig reared under backyard farming in the Bucaramanga metropolitan area, Northeast Colombia.

Materials and Methods:

From September to December 2019, a total of 558 fecal samples from 64 backyard pig farms were examined for the presence of enteric protozoan infection. The coprological diagnosis was done by direct examination using Lugol’s iodine solution, buffered saline solution, and Kinyoun technique. In addition, blood samples were collected from 200 pigs. Serum was collected and used for the detection of Trichinella spiralis and Taenia solium cysticercosis infections, using the enzyme-linked immunosorbent assay.

Results:

The overall prevalence of zoonotic protozoa in the Bucaramanga metropolitan area was 65.2%, reporting 52.7% prevalence for Balantidium coli, 33.7% for Entamoeba coli, and 5.7% for Cryptosporidium spp. Regarding the prevalence by municipalities, there was no statistical association (p>0.05), indicating that the prevalence was similar in the region under study. Pigs >7 months of age showed to be a risk factor for B. coli infection, indicating that the prevalence increases with the age, while pigs raised at >1000 masl and access to latrines, increased infection risk for E. coli and Cryptosporidium spp. infections. In the present study, T. spiralis infection was not detected in the analyzed sera, while T. solium cysticercosis infection was found to be 40.5%.

Conclusion:

The high prevalence of protozoan infections and porcine cysticercosis reported in this study could be due to poor facilities, and lack of hygiene in the facilities, and suggests the possible transmission of these parasite populations between pigs and humans, thus increasing the transmission of parasites zoonotic potential. Therefore, appropriate sanitary management practices and deworming programs should be adopted to reduce the prevalence of these infectious agents.

Modified DMEM xenic culture medium for propagation, isolation and maintenance of Balantioides coli

Balantioides coli is a known ciliated zoonotic protozoan that mainly causes diarrhea in humans and pigs. An efficient and reliable culture system for this parasite remains unavailable until now. In this study, a modified Dulbecco's modified eagle medium (DMEM) with pH 7.0-7.5, containing 5 mg/mL starch and 20% new calf serum, was optimized for propagation of B. coli at 28°C-32°C. At the growth-peaking stage, the average trophozoite density was up to 12,970 trophozoites per milliliter. A reproducible protocol for isolation and maintenance of this parasite was also developed based on the modified DMEM culture medium. Moreover, cloning results of B. colipopulations showed that 250 trophozoites in 3 mL modified DMEM medium were the minimal number of trophozoites that propagated to the growth-peaking stage, and finally obtained the individual population. However, less than 250 trophozoites failed to continuously grow in the modified DMEM culture medium under the optimal conditions for growth of B. coli. These data showed that the modified DMEM culture medium is an ideal and efficient medium for propagation and maintenance of B. coli in vitro and will help studies on its biology, genome, transcriptome, proteome, and drug screening.

Aptamer-based approaches for the detection of waterborne pathogens

Waterborne ailments pose a serious threat to public health and are a huge economic burden. Lack of hygiene in drinking and recreational water is the chief source of microbial pathogens in developing countries. Poor water quality and sanitation account for more than 3.4 million deaths a year worldwide. This has urged authorities and researchers to explore different avenues of pathogen detection. There is a growing demand for rapid and reliable sensor technologies, in particular those that can detect in situ and perform in harsh conditions. Some of the major waterborne pathogens include Vibrio cholerae, Leptospira interrogans, Campylobacter jejuni, Shigella spp., enterotoxigenic Escherichia coli, Clostridium difficile, Cryptosporidium parvum, Entamoeba histolytica, and Hepatitis A virus. While conventional methods of pathogen detection like serodiagnosis and microbiological methods have been superseded by nucleic acid amplification methods, there is still potential for improvement. This review provides an insight into aptamers and their utility in the form of aptasensors. It discusses how aptamer-based approaches have emerged as a novel strategy and its advantages over more resource-intensive and complex biochemical approaches.