ABSTRACT
Blastocystis hominis is a common parasitic protozoa in human and animal intestines; however, its pathogenicity remains controversial. Construction of animal models is of great significance to investigate the pathogenicity, pathogenic mechanisms and drug screening of B. hominis. Experimental animals, mode of infections, parasite strains and host immune status are important factors affecting the successful modeling of B. hominis infections in animals. Hereby, we review the progress of researches on animal models of B. hominis infections, and summarize the influencing factors and application of animal models of B. hominis infections, in order to provides insights into the selection of animals models of B. hominis infections.
ABSTRACT
Blastocystis hominis is a parasite that parasitizes in the intestines of humans and animals, and is closely related to a variety of gastrointestinal diseases such as abdominal pain and diarrhea. B. hominis is distributed worldwide, and the prevalence of B. hominis infections and dominant subgenotypes vary in countries and in regions from the same country. This paper reviews the global prevalence of B. hominis human infections, its subtypes and geographical distribution, so as to provide insights into the understanding of the global epidemiology of B. hominis and the management of B. hominis infections.
ABSTRACT
Toxoplasma gondii is a protozoan parasite with a broad range of intermediate hosts. Chickens as important food-producing animals can also serve as intermediate hosts. To date, experimental studies on the pathogenicity of T. gondii in broiler chickens were rarely reported. The objective of the present study was to compare the pathogenicity of 5 different T. gondii strains (RH, CN, JS, CAT2, and CAT3) from various host species origin in 10-day-old chickens. Each group of chickens was infected intraperitoneally with 5 x 10(8), 1 x 10(8), 1 x 10(7), and 1 x 10(6) tachyzoites of the 5 strains, respectively. The negative control group was mockly inoculated with PBS alone. After infection, clinical symptoms and rectal temperatures of all the chickens were checked daily. Dead chickens during acute phage of the infection were checked for T. gondii tachyzoites by microscope, while living cases were checked for T. gondii infection at day 53 post-inoculation (PI) by PCR method. Histopathological sections were used to observe the pathological changes in the dead chickens and the living animals at day 53 PI. No significant differences were found in survival periods, histopathological findings, and clinical symptoms among the chickens infected with the RH, CN, CAT2, and CAT3 strains. Histopathological findings and clinical symptoms of the JS (chicken origin) group were similar to the others. However, average survival times of infected chickens of the JS group inoculated with 5 x 10(8) and 1 x 10(8) tachyzoites were 30.0 and 188.4 hr, respectively, significantly shorter than those of the other 4 mammalian isolates. Chickens exposed to 10(8) of T. gondii tachyzoites and higher showed acute signs of toxoplasmosis, and the lesions were relatively more severe than those exposed to lower doses. The results indicated that the pathogenicity of JS strain was comparatively stronger to the chicken, and the pathogenicity was dose-dependent.