Review

Authors: Quan Liu, Ze-Dong Wang, Si-Yang Huang...

Toxoplasmosis, caused by the obligate intracellular protozoan Toxoplasma gondii, is an important zoonosis with medical and veterinary importance worldwide. The disease is mainly contracted by ingesting undercooked or raw meat containing viable tissue cysts, or by ingesting food or water contaminated with oocysts. The diagnosis and genetic characterization of T. gondii infection is crucial for the surveillance, prevention and control of toxoplasmosis. Traditional approaches for the diagnosis of toxoplasmosis include etiological, immunological and imaging techniques. Diagnosis of toxoplasmosis has been improved by the emergence of molecular technologies to amplify parasite nucleic acids. Among these, polymerase chain reaction (PCR)-based molecular techniques have been useful for the genetic characterization of T. gondii. Serotyping methods based on polymorphic polypeptides have the potential to become the choice for typing T. gondii in humans and animals. In this review, we summarize conventional non-DNA-based diagnostic methods, and the DNA-based molecular techniques for the diagnosis and genetic characterization of T. gondii. These techniques have provided foundations for further development of more effective and accurate detection of T. gondii infection. These advances will contribute to an improved understanding of the epidemiology, prevention and control of toxoplasmosis.

Topics: Animals; Diagnostic Tests, Routine; Humans; Toxoplasma; Toxoplasmosis

PubMed: 26017718
DOI: 10.1186/s13071-015-0902-6

Authors: Rachel M Chalmers, Angharad P Davies, Kevin Tyler...

The protozoan Cryptosporidium is notorious for its resistance to chlorine disinfection, a mainstay of water treatment. Human infections, mainly of the small intestine, arise from consumption of faecally contaminated food or water, environmental exposure, and person-to-person or animal-to-person spread. Acute gastrointestinal symptoms can be prolonged but are usually self-limiting. Problems arise with immune-deficient, including malnourished, people including chronic diarrhoea, hepato-biliary tree and extra-gastrointestinal site infection, and few options for treatment or prevention exist. Although genomics has enabled refined classification, identification of chemotherapeutic targets and vaccine candidates, and putative factors for host adaption and pathogenesis, their confirmation has been hampered by a lack of biological tools.

Topics: Animals; Cryptosporidiosis; Cryptosporidium; Genome, Protozoan; Humans; Phylogeny

PubMed: 31268415
DOI: 10.1099/mic.0.000764

Review

Authors: Chenyang Lu, Yaqun Yan, Fuchun Jian...

As a common parasitic disease in animals, coccidiosis substantially affects the health of the host, even in the absence of clinical symptoms and intestinal tract colonization. Gut microbiota is an important part of organisms and is closely related to the parasite and host. Parasitic infections often have adverse effects on the host, and their pathogenic effects are related to the parasite species, parasitic site and host-parasite interactions. Coccidia-microbiota-host interactions represent a complex network in which changes in one link may affect the other two factors. Furthermore, coccidia-microbiota interactions are not well understood and require further research. Here, we discuss the mechanisms by which coccidia interact directly or indirectly with the gut microbiota and the effects on the host. Understanding the mechanisms underlying coccidia-microbiota-host interactions is important to identify new probiotic strategies for the prevention and control of coccidiosis.

Topics: Animals; Coccidia; Coccidiosis; Gastrointestinal Microbiome; Intestines; Microbiota

PubMed: 34660347
DOI: 10.3389/fcimb.2021.751481

Review

Authors: Anna Sophia Feix, Teresa Cruz-Bustos, Bärbel Ruttkowski...

The subclass Coccidia comprises a large group of protozoan parasites, including important pathogens of humans and animals such as Toxoplasma gondii, Neospora caninum, Eimeria spp., and Cystoisospora spp. Their life cycle includes a switch from asexual to sexual stages and is often restricted to a single host species. Current research on coccidian parasites focuses on cell biology and the underlying mechanisms of protein expression and trafficking in different life stages, host cell invasion and host-parasite interactions. Furthermore, novel anticoccidial drug targets are evaluated. Given the variety of research questions and the requirement to reduce and replace animal experimentation, in vitro cultivation of Coccidia needs to be further developed and refined to meet these requirements. For these purposes, established culture systems are constantly improved. In addition, new in vitro culture systems lately gained considerable importance in research on Coccidia. Well established and optimized in vitro cultures of monolayer cells can support the viability and development of parasite stages and even allow completion of the life cycle in vitro, as shown for Cystoisospora suis and Eimeria tenella. Furthermore, new three-dimensional cell culture models are used for propagation of Cryptosporidium spp. (close relatives of the coccidians), and the infection of three-dimensional organoids with T. gondii also gained popularity as the interaction between the parasite and host tissue can be studied in more detail. The latest advances in three-dimensional culture systems are organ-on-a-chip models, that to date have only been tested for T. gondii but promise to accelerate research in other coccidians. Lastly, the completion of the life cycle of C. suis and Cryptosporidium parvum was reported to continue in a host cell-free environment following the first occurrence of asexual stages. Such axenic cultures are becoming increasingly available and open new avenues for research on parasite life cycle stages and novel intervention strategies.

Topics: Animals; Humans; Parasites; Cryptosporidiosis; Cryptosporidium; Toxoplasma; Sarcocystidae; Life Cycle Stages

PubMed: 36400306
DOI: 10.1016/j.ijpara.2022.10.002

Authors: A Ros Die, J M Nogueira Coito

Topics: Aged; Diarrhea; Feces; Humans; Isospora; Isosporiasis; Male; Paraproteinemias

PubMed: 28712665
DOI: 10.1016/j.cmi.2017.07.009

Review

Authors: Ross G Douglas, Robert W Moon, Friedrich Frischknecht...

Apicomplexan parasites are a group of eukaryotic protozoans with diverse biology that have affected human health like no other group of parasites. These obligate intracellular parasites rely on their cytoskeletal structures for giving them form, enabling them to replicate in unique ways and to migrate across tissue barriers. Recent progress in transgenesis and imaging tools allowed detailed insights into the components making up and regulating the actin and microtubule cytoskeleton as well as the alveolate-specific intermediate filament-like cytoskeletal network. These studies revealed interesting details that deviate from the cell biology of canonical model organisms. Here we review the latest developments in the field and point to a number of open questions covering the most experimentally tractable parasites: , the causative agent of malaria; , the causative agent of toxoplasmosis; and , a major cause of diarrhea.

Topics: Cytoskeleton; Humans; Toxoplasma; Animals; Apicomplexa; Plasmodium; Microtubules; Cryptosporidium

PubMed: 39094056
DOI: 10.1146/annurev-micro-041222-011539

Review

Authors: Vitaliano A Cama, Blaine A Mathison

The coccidians Cryptosporidium spp, Cyclospora cayetanensis, and Cystoisospora belli and the flagellate Giardia duodenalis are pathogenic protozoa associated with gastrointestinal manifestations. Diagnosis relies heavily on microscopy, and although ova-and-parasite examinations can detect Giardia and Cystoisospora, Cryptosporidium and Cyclospora often require specific diagnostic requests. Approved non-microscopy methods are available for Giardia and Cryptosporidium, although negative results are frequently followed by microscopic assays. Polymerase chain reaction-based methods are not frequently used for diagnosis of Giardia and Cryptosporidium and have been used primarily for epidemiologic or outbreak investigations of Giardia and Cryptosporidium.

Topics: Antigens, Protozoan; Coccidia; Coccidiosis; Diagnosis, Differential; Giardia lamblia; Giardiasis; Humans; Immunoassay; Sensitivity and Specificity; Specimen Handling

PubMed: 26004650
DOI: 10.1016/j.cll.2015.02.010

Authors: Edward L Arsura, Ravi K Bobba, Chakradhar M Reddy...

Topics: Amphotericin B; Animals; Antiprotozoal Agents; Child; Coccidia; Coccidiosis; Female; Humans; Injections, Intravenous; Pericardiocentesis; Pericarditis; Sputum

PubMed: 16260168
DOI: 10.1016/j.ijid.2005.03.004

Review

Authors: Michal Pakandl

This article summarises the current knowledge of the rabbit coccidia and the disease they cause. Various aspects, such as life cycles, localisation in the host, pathology and pathogenicity, immunity and control, are discussed.

Topics: Animals; Coccidiosis; Eimeria; Rabbits

PubMed: 19827358
DOI: 10.14411/fp.2009.019

Meta-Analysis

Authors: Qing-Long Gong, Wen-Xuan Zhao, Yan-Chun Wang...

BACKGROUND

Swine coccidiosis, a protozoan disease caused by coccidia, can result in diarrhoea and weight loss in piglets and even economic losses in the pig industry. Here, we report the first systematic review and meta-analysis of the prevalence of coccidia (including Eimeria spp. and Cystoisospora suis) in pigs in China.

METHODS

Five databases (PubMed, ScienceDirect, Chinese Web of Knowledge, Wanfang, and Chongqing VIP) were searched and 50 studies (46,926 domestic pigs, 22 provinces) ultimately identified pertaining to the prevalence of coccidia infection from 1980 to 2019. We incorporated the effect size using the random-effects model in the "meta" package in R software and conducted univariate and multivariate meta-regression analyses using a mixed-effects model.

RESULTS

The pooled prevalence rate of coccidia in pigs was 21.9%, including the C. suis infection rate of 9.1%. The highest prevalence of coccidia (39.6%) was found in northwest China, and this region also presented the lowest prevalence of C. suis (4.7%). In the subgroup analysis based on sampling year, the highest prevalence of coccidia was detected in 2001 or earlier (32.6%), whereas the lowest rate was found in 2012 or later (14.3%). An opposite trend was observed for C. suis (5.5% in 2000 or earlier vs 14.4% in 2000 or later). The prevalence of coccidia in extensive farming systems (29.5%) was higher than that in intensive farming systems (17.3%). In contrast, the point estimate of C. suis prevalence was lower in the extensive farming systems (5.1%) than in the intensive farming systems (10.0%), but the difference was not significant (P > 0.05). Among the four age categories, the highest total coccidia prevalence (26.2%) was found in finishing pigs, followed by suckling piglets (19.9%), whereas the highest prevalence of C. suis (14.9%) was observed in suckling piglets.

CONCLUSIONS

Our findings suggest that coccidia infection in Chinese pigs is common, although the prevalence of C. suis in pigs does not receive sufficient attention. We recommend the rational use of anticoccidial drugs to avoid drug resistance and the development of preventive and control measures for C. suis to reduce the incidence of swine coccidiosis.

Topics: Animals; China; Coccidia; Coccidiosis; Feces; Prevalence; Swine; Swine Diseases

PubMed: 33971953
DOI: 10.1186/s13071-021-04611-x