Occurrence of Toxoplasma gondii in domestic rabbits of Northeastern Brazil

Toxoplasma gondii infection in European brown hares (Lepus europaeus) in Brazil

Toxoplasmosis is a worldwide zoonosis that affects warm-blooded animals, including humans. Wild animals can act as intermediate hosts of this pathogen; thus, this study aims to detect Toxoplasma gondii infection in invasive European brown hares in Brazil. For this, 72 wild European brown hares were captured from July 2020 to June 2022 in three Brazilian states: São Paulo, Paraná, and Rio Grande do Sul. The diagnostic of Toxoplasma gondii infection was performed by bioassay in mouse, histopathology in Hematoxylin-Eosin-stained tissue sections (brain, liver, lungs, kidneys, and small intestine), serology by IFAT, and molecular techniques by conventional PCR and qPCR. The combined prevalence of the different diagnostic methods was 51.4% (37/72, CI= 40.1 - 62.6 %), and there was no statistical difference between sexes, age range, or geographical region of the hosts. Mouse bioassay was the technique that detected more positive hares. To our knowledge, this is the first confirmation of Toxoplasma gondii infection in invasive European brown hares in Brazil. These animals act as reservoirs and potential infection source for carnivores and other wild and domestic animals, including humans, thus contributing to perpetuate the disease cycle in São Paulo, Paraná, and Rio Grande do Sul States. Research such as the present study is necessary to raise awareness about the role of animals in the disease cycle.

Epidemiological and Public Health Significance of Toxoplasma gondii Infection in Wild Rabbits and Hares: 2010-2020

Toxoplasmosis is a zoonosis of global distribution, and Toxoplasma gondii infections are common in humans and animals worldwide. Hares and rabbits are important small game species, and their meat is consumed by humans in many countries. Demand for rabbit meat for human consumption is increasing; therefore, toxoplasmosis in rabbits and hares is of epidemiological significance. Viable T. gondii has been isolated from rabbits. The present review summarizes worldwide information on the seroprevalence, parasitological investigations, clinical cases, isolation, and genetic diversity of T. gondii in wild rabbits, free domestic rabbits, hares, and other rabbits from 2010 to 2020. Differences in prevalence, susceptibility, genetic variants, and clinical implications of T. gondii infection in rabbits and hares are discussed. This review will be of interest to biologists, parasitologists, veterinarians, and public health workers. Additional studies are needed to increase our knowledge of genetic variants and the population structure of T. gondii in rabbits and hares and to understand the differences in susceptibility to T. gondii in hares in different areas.

Granulomas in parasitic diseases: the good and the bad

Parasitic diseases affect more than one billion people worldwide, and most of them are chronic conditions in which the treatment and prevention are difficult. The appearance of granulomas, defined as organized and compact structures of macrophages and other immune cells, during various parasitic diseases is frequent, since these structures will only form when individual immune cells do not control the invading agent. Th2-typering various parasitic diseases are frequent, since these structures will only form when individual immune cells do not control the invading agent. The characterization of granulomas in different parasitic diseases, as well as recent findings in this field, is discussed in this review, in order to understand the significance of the granuloma and its modulation in the host-parasite interaction and in the immune, pathological, and parasitological aspects of this interaction. The parasitic granulomatous diseases granulomatous amebic encephalitis, toxoplasmosis, leishmaniasis, neurocysticercosis, and schistosomiasis mansoni are discussed as well as the mechanistic and dynamical aspects of the infectious granulomas.

Comparison of Seroprevalence and PCR Results in the Detection of Toxoplasma gondii in Pet Rabbits in Poland

Toxoplasma gondii infections are prevalent in humans and animals worldwide. The aim of the study was to estimate the seroprevalence of T. gondii in pet rabbits, as well the presence of T. gondii DNA in their blood. A total of 360 pet rabbits were investigated for the presence of antibodies and antigens of T. gondii in blood samples using a modified agglutination test (MAT) and nested PCR, respectively. Antibodies against T. gondii were found in 44 (12.12%) of pet rabbits. In rabbits that received unwashed vegetables 13.13% were positive for T. gondii antibodies, whereas all rabbits that received washed vegetables were seronegative. The prevalence of anti-T. gondii antibodies was statistically higher in samples collected from ill rabbits (45.45%) compared with healthy ones (8.87%), as well in the group of rabbits that had contact with cats (16.13%) compared with those without contact with cats (3.57%). The percentage of seropositive samples derived from all three sampling regions of Poland was as follows: Silesia (12.20%), Lower Silesia (6.09%), and Lesser Poland (18.03%). No statistical differences in seroprevalence were observed according to age or sex of rabbits. All tested blood samples were negative for the T. gondii B1 gene in nested PCR. This is the first study of seroprevalence and the presence of T. gondii in the blood of pet rabbits in Poland. Our study indicates that health status of rabbits, contact with cats, as well sampling region may have an important impact on the prevalence of T. gondii infection.

Occurrence and genetic characterization of Toxoplasma gondii and Neospora caninum in slaughtered domestic rabbits in central China

Currently, information on the occurrence and genetic characterization of Toxoplasma gondii and Neospora caninum in tissues of rabbits in China is lacking. In this study, brain and heart samples from 470 slaughtered domestic rabbits were collected in Henan Province, Central China. The occurrence rate of T. gondii and N. caninum DNA detected by nested PCR was 2.8% and 2.1%, respectively. There were no significant differences (p > 0.05) in the frequency of the two parasite infections in relation to sex, breed, and region. Three out of 13 T. gondii-positive samples were completely or partially genotyped at 11 genetic markers using PCR-RFLP, and one was identified as ToxoDB genotype #9. For N. caninum, three different sequences at the ITS1 region and two genotypes at the MS5 microsatellite locus were identified. To our knowledge, this is the first genetic characterization of N. caninum isolates from rabbits.

Seroprevalence of Toxoplasma gondii and Encephalitozoon cuniculi among domestic rabbits in central China

Rabbits (Oryctolagus cuniculus) are frequently reared for meat production in China. The aim of this study was to assess the seroprevalence of Toxoplasma gondii and Encephalitozoon cuniculi, and risk factors of infection in domestic rabbits raised in Henan province, central China. 1,213 serum samples of domestic rabbits were collected and tested for anti-T. gondii and anti-E. cuniculi antibodies using a modified agglutination test (MAT) and an enzyme-linked immunosorbent assay (ELISA), respectively. The serum positive rates of T. gondii and E. cuniculi were 128/1,213 (10.55%) and 235/1,213 (19.37%), respectively. Co-infection of T. gondii and E. cuniculi was demonstrated in 84 specimens; 44 rabbits were seropositive for T. gondii alone, while 151 rabbits were seropositive for E. cuniculi alone. The main risk factors simultaneously associated with T. gondii and E. cuniculi infection were the age of the rabbit, the type of food, and the rabbit rearing system. Serum positive rates of T. gondii and E. cuniculi among domestic rabbits were high, indicating the possibility of public health issues.