Isolation and Characterization of a Viable Toxoplasma gondii from Captive Caracal (Caracal caracal).

Toxoplasma gondii is a widespread protozoan parasite that infects most warm-blooded animals, and felids can serve as intermediate and definitive hosts. Pathological diagnosis and serological and etiological investigations were conducted on a captive caracal (Caracal caracal) carcass collected from China in 2022. Pathological diagnosis revealed that cardiac insufficiency, pulmonary edema, hepatic failure, and renal insufficiency were the causes of the caracal's death. A modified agglutination test (cut-off: 1:25) revealed that IgG antibodies against T. gondii were present in the myocardium juice (1:1600), ascitic fluid (1:3200), and hydropericardium (1:800). A viable T. gondii (TgCaracalCHn2) strain was isolated from the tissue samples (heart, brain, spleen, and skeletal muscle) of this caracal using a mouse bioassay. The genotype of TgCaracalCHn2 was ToxoDB#5 (Type II variant), as determined via RFLP-PCR. The strain was avirulent in Swiss mice and matched the prediction of ROP18 and ROP5 gene alleles of TgCaracalCHn2 (2/2). Mild tissue cysts (203 ± 265) were observed in mice brains after inoculation with TgCaracalCHn2 tachyzoites. ToxoDB#5 is the dominant genotype in North American wildlife, and this is the first documented isolation of T. gondii ToxoDB#5 from China. This indicates that caracal plays an important role in the transmission of this T. gondii genotype.

A review of anorexia induced by T-2 toxin.

The presence of anorexia in animals is the most well-known clinical symptom of T-2 toxin poisoning. T-2 toxin is the most characteristic type A toxin in the trichothecene mycotoxins. The consumption of T-2 toxin can cause anorexic response in mice, rats, rabbits, and other animals. In this review, the basic information of T-2 toxin, appetite regulation mechanism and the molecular mechanism of T-2 toxin-induced anorectic response in animals are presented and discussed. The objective of this overview is to describe the research progress of anorexia in animals produced by T-2 toxin. T-2 toxin mainly causes antifeedant reaction through four pathways: vagus nerve, gastrointestinal hormone, neurotransmitter and cytokine. This review aims to give an academic basis and useable reference for the prevention and treatment of clinical symptoms of anorexia in animals resulting from T-2 toxin.

Low Prevalence of Toxoplasma gondii in Sheep and Isolation of a Viable Strain from Edible Mutton from Central China.

Sheep are highly susceptible to Toxoplasma gondii, and miscarriage is the main clinical feature. This study investigated 227 sheep samples (210 myocardial tissues from slaughterhouses, 6 ewe serum samples, 3 aborted fetuses, and 8 dead lambs from veterinary clinics) from central China for T. gondii infection. Antibodies against T. gondii were detected using the modified agglutination test (MAT). PCR was performed to detect T. gondii DNA in the tissue samples. The results showed that four samples were seropositive (MAT titer ≥ 1:100), with a seroprevalence of 1.8% (4/227). The seropositive samples included two myocardial samples from a slaughterhouse, one ewe and its aborted fetus from a veterinary clinic. The results revealed that 7 out of 207 (3.4%) sheep tissue samples were PCR-positive, including two myocardial tissue samples from slaughterhouses, three aborted fetuses, and two lambs from veterinary clinics. Toxoplasma gondii vertical transmission had occurred in two of three pairs of ewes and her pups. One viable T. gondii strain (TgSheepCHn14) was isolated from the myocardial tissues of sheep from a slaughterhouse. Tachyzoites were obtained from cell cultures at 70 days following seeding in the brains and lungs of mice. This strain was non-lethal to Swiss mice. The number of parasite brain cysts in mice decreased with time post-infection (p < 0.05). Overall, the prevalence of T. gondii in the sheep samples was low. Although the samples were scattered, and not from planned collections, the current study detected T. gondii antibodies and DNA in aborted fetuses, indicating that vertical transmission could occur and maintain the parasites in sheep herds without exogenous infection.

T-2 toxin metabolism and its hepatotoxicity: New insights on the molecular mechanism and detoxification.

T-2 toxin, a type A trichothecene, is a secondary metabolite produced by Fusarium poae, Fusarium sporotrichioides, and Fusarium tricinctum. As the most toxic trichothecenes, T-2 toxin causes severe damage to multiple organs, especially to liver. However, the contamination of T-2 toxin covers a wide range of plants, including nuts, grains, fruits and herbs globally. And due to chemical stability of T-2 toxin, it is difficult to be completely removed from the food and feeds, which poses a great threat to human and animal health. Liver is the major detoxifying organ which also makes it the main target of T-2 toxin. After being absorbed by intestine, the first pass effect will reduce the level of T-2 toxin in blood indicating that liver is the main metabolic site of T-2 toxin in vivo. In this review, updated researches on the hepatotoxicity of T-2 toxin were summarized. The metabolic characteristic of T-2 toxin in vivo was introduced. The main hepatotoxic mechanisms of T-2 toxin are oxidative stress, mitochondrial damage, deoxyribonucleic acid (DNA) methylation, autophagy and apoptosis. The remission of the hepatotoxicity induced by T-2 toxin was also studied in this review followed by new findings on the detoxification of hepatotoxicity induced by T-2 toxin. The review aimed to offer a comprehensive view and proposes new perspectives in the field of hepatotoxicity induced by T-2 toxin.

Nrf2: A Main Responsive Element of the Toxicity Effect Caused by Trichothecene (T-2) Mycotoxin.

T-2 toxin, the most toxic type A trichothecene mycotoxin, is produced by Fusarium, and is widely found in contaminated feed and stored grains. T-2 toxin is physicochemically stable and is challenging to eradicate from contaminated feed and cereal, resulting in food contamination that is inescapable and poses a major hazard to both human and animal health, according to the World Health Organization. Oxidative stress is the upstream cause of all pathogenic variables, and is the primary mechanism through which T-2 toxin causes poisoning. Nuclear factor E2-related factor 2 (Nrf2) also plays a crucial part in oxidative stress, iron metabolism and mitochondrial homeostasis. The major ideas and emerging trends in future study are comprehensively discussed in this review, along with research progress and the molecular mechanism of Nrf2's involvement in the toxicity impact brought on by T-2 toxin. This paper could provide a theoretical foundation for elucidating how Nrf2 reduces oxidative damage caused by T-2 toxin, and a theoretical reference for exploring target drugs to alleviate T-2 toxin toxicity with Nrf2 molecules.

Deoxynivalenol induces testicular ferroptosis by regulating the Nrf2/System Xc-/GPX4 axis.

Deoxynivalenol (DON) is the most common mycotoxin contaminant in food and feed. DON accumulation in food chain severely threatens human and animal health due to the toxic effects on the reproduction system. However, the underlying mechanism of DON on male reproductive dysfunction is still in debate and there is little information about whether DON triggers testicular ferroptosis. In this study, male C57BL/6 mice were divided into 4 groups and treated by oral gavage with 0, 0.5, 1.0, 2.0 mg/kg BW DON for 28 days. Firstly, we proved that male reproduction dysfunction was induced by DON through assessing testicular histopathology, serum testosterone level as well as blood-testis barrier integrity. Then, we verified ferroptosis occurred in DON-induced testicular dysfunction model through disrupting iron homeostasis, increasing lipid peroxidation and inhibiting system Xc-/Gpx4 axis. Notably, the present data showed DON reduced antioxidant capacity via blocking Nrf2 pathway to lead to the further weakness of ferroptosis resistance. Altogether, these results indicated that DON caused mice testicular ferroptosis associated with inhibiting Nrf2/System Xc-/GPx4 axis, which provided that maintaining testicular iron homeostasis and activating Nrf2 pathway may be a potential target for alleviating testicular toxicity of DON in the future.

Dietary yucca extract and Clostridium butyricum promote growth performance of weaned rabbits by improving nutrient digestibility, intestinal development, and microbial composition.

Yucca has abundant amounts of polyphenolics, steroidal saponins, and resveratrol and its extract can be used as a feed additive in the animal husbandry, which might contribute to the improvement in the growth and productivity in rabbit production. Hence, the current study aimed to examine the effects of yucca extract alone and in combination with Clostridium butyricum (C. butyricum) on growth performance, nutrient digestibility, muscle quality, and intestinal development of weaned rabbits. A total of 400 40-day-old male rabbits were randomly divided into 4 treatment groups for 40 days: (1) basal diet group, (2) basal diet contained 300 mg/kg of yucca extract, (3) basal diet supplemented with 0.4 × 1010 colony-forming units (CFU)/kg of C. butyricum, and (4) the blend of 0.4 × 1010/kg CFU of C. butyricum and 300 mg/kg of yucca extract. The supplementation of yucca extract or C. butyricum increased body weight (BW) of rabbits depending on the age, the combined addition of yucca extract and C. butyricum significantly increased BW, weight gain, and feed intake, companying with increased the digestibility of crud protein, fiber, phosphorous, and calcium as compared to control diet (P < 0.05). Furthermore, yucca extract and C. butyricum treatment alone and in combination notably increased the villus high and the ratio of villus high to crypt depth of rabbits (P < 0.05). The combined supplementation of yucca extract and C. butyricum altered the intestinal microbiota of rabbits, as demonstrated by increased the abundance of beneficial bacteria Ruminococcaceae and decreased the proportion of pathogenic bacteria such as Pseudomonadaceae and S24-7. In addition, the rabbits fed the diet with yucca extract and the blend of yucca extract and C. butyricum had significantly increased pH45min, decreased pressing loss, drip loss, and shears force when compared with rabbits received control diet (P < 0.05). Diet with C. butyricum or its mixture with yucca extract increased the fat content of meat, while the combined addition of yucca extract and C. butyricum declined the content of fiber in meat (P < 0.05). Collectively, the combined use of yucca extract and C. butyricum showed better results on growth performance and meat quality, which might be closely associated with the improved intestinal development and cecal microflora of the rabbits.

p38 mediates T-2 toxin-induced Leydig cell testosterone synthesis disorder.

T-2 toxin is an unavoidable food and feed contaminant that seriously threatens human and animal health. Exposure to T-2 toxin can cause testosterone synthesis disorder in male animals, but the molecular mechanism is still not completely clear. The MAPK pathway participates in the regulation of testosterone synthesis by Leydig cells, but it is unclear whether the MAPK pathway participates in T-2 toxin-induced testosterone synthesis disorders. In this research, testosterone synthesis capacity, testosterone synthase expression and MAPK pathway activation were examined in male mice and TM3 cells exposed to T-2 toxin. The results showed that T-2 toxin exposure decreased testicular volume and caused pathological changes in the microstructure and ultrastructure of testicular Leydig cells. T-2 toxin exposure also decreased testicular testosterone content and the protein expression of testosterone synthase. In vitro, T-2 toxin inhibited cell viability and decreased the expression of testosterone synthase in TM3 cells, and it decreased the testosterone contents in cell culture supernatants. Moreover, T-2 toxin activated the MAPK pathway by increasing the expression of p38, JNK and ERK as well as the expression of p-p38, p-JNK and p-ERK in testis and TM3 cells. The p38 molecular inhibitor (SB203580) significantly alleviated the T-2 toxin-induced decrease in testosterone synthase expression in TM3 cells and the T-2 toxin-induced reduction in testosterone content in TM3 cell culture supernatants. In summary, p38 mediates T-2 toxin-induced Leydig cell testosterone synthesis disorder.

Epidemiology and isolation of viable Toxoplasma gondii strain from macropods.

Wallabies and other marsupials are highly susceptible to Toxoplasma gondii. In this study, 26 macropod samples were collected (8 red kangaroos, 4 Parma wallabies, 8 red-necked wallabies, 5 albino red-necked wallabies and 1 Eastern grey kangaroo), including tissue (n = 9) and serum (n = 17) samples. According to the modified agglutination test (MAT) results (cutoff 1:25), 50% (95% Cl: 32.06-67.94%) of the macropods had T. gondii antibodies. Among them, species, survival state, and sampling date were risk factors for T. gondii susceptibility (P < 0.05). T. gondii DNA was detected in two (cases #14 and #15) of the nine cases obtained from macropod tissues. One viable T. gondii strain (TgRooCHn4) was isolated from an albino red-necked wallaby (Macropus rufogriseus, case #14) via bioassay in mice. TgRooCHn4 belongs to ToxoDB genotype #3, using the 10 multilocus PCR-RFLP markers. The ROP18 and ROP5 gene allele types of TgRooCHn4 were 2/2, which was predicted to be non-lethal to mice. The virulence of TgRooCHn4 tachyzoites was avirulent in mice. Most macropods sampled from Hernan province in 2021 and 2022 were positive with T. gondii infection. A flood occurred in July 2021 in Zhengzhou from Henan province may promote the transmission of T. gondii oocysts. To our knowledge, this is the first T. gondii strain isolated from albino red-necked wallaby. However, further investigation is required to enhance our understanding of the transmission and prevention of toxoplasmosis in sensitive zoo animals.

Additional evidence of tigers (Panthera tigris altaica) as intermediate hosts for Toxoplasma gondii through the isolation of viable strains.

Toxoplasmosis is one of the most common zoonotic diseases in the world. Felines excrete Toxoplasma gondii oocysts, which play a key role in the transmission of this protozoon. Pathological diagnoses were performed on four carcasses of captive tigers collected from 2019 to 2021 in China, and T. gondii was surveyed using serology, molecular analysis, and aetiology. Striated muscle samples of the tigers (n = 4) were bioassayed in mice. DNA derived from T. gondii tachyzoites was isolated and characterized using PCR-RFLP. The pathological diagnoses revealed that ageing, declined immune function, liver, and kidney failures caused the deaths in the tigers examined. A modified agglutination test (cut-off: 1:25) revealed that IgG antibodies to T. gondii were 100% (4/4) in the captive tigers. Two viable T. gondii strains (TgTigerCHn3 and TgTigerCHn4) were isolated from tiger striated muscles and seeded on the Vero cell culture for further propagation. The genotypes of TgTigerCHn3 and TgTigerCHn4 were ToxoDB#20 and ToxoDB#2, respectively. The two strains were avirulent for Swiss mice, which matched the ROP18 and ROP5 gene alleles of TgtigerCHn3 (3/4) and TgtigerCHn4 (3/3). Few brain tissue cysts (0-213) were observed in the mice after inoculation with TgTigerCHn3 and TgTigerCHn4. This is the first documented isolation of T. gondii ToxoDB#20 and ToxoDB#2 from tigers. The results provide additional direct evidence of tiger as intermediate hosts for T. gondii. Tigers in the zoos may potentially transmit T. gondii to other animals and humans.

Review of the Role of Ferroptosis in Testicular Function.

Iron is an important metal element involved in the regulation of male reproductive functions and has dual effects on testicular tissue. A moderate iron content is necessary to maintain testosterone synthesis and spermatogenesis. Iron overload can lead to male reproductive dysfunction by triggering testicular oxidative stress, lipid peroxidation, and even testicular ferroptosis. Ferroptosis is an iron-dependent form of cell death that is characterized by iron overload, lipid peroxidation, mitochondrial damage, and glutathione peroxidase depletion. This review summarizes the regulatory mechanism of ferroptosis and the research progress on testicular ferroptosis caused by endogenous and exogenous toxicants. The purpose of the present review is to provide a theoretical basis for the relationship between ferroptosis and male reproductive function. Some toxic substances or danger signals can cause male reproductive dysfunction by inducing testicular ferroptosis. It is crucial to deeply explore the testicular ferroptosis mechanism, which will help further elucidate the molecular mechanism of male reproductive dysfunction. It is worth noting that ferroptosis does not exist alone but rather coexists with other forms of cell death (such as apoptosis, necrosis, and autophagic death). Alleviating ferroptosis alone may not completely reverse male reproductive dysfunction caused by various risk factors.

Deoxynivalenol triggers porcine intestinal tight junction disorder: Insights from mitochondrial dynamics and mitophagy.

Deoxynivalenol (DON) is universally detected trichothecene in most cereal commodities, which is considered as a major hazardous material for human and animal health. Intestine is the most vulnerable organ with higher concentration of DON than other organs, owing to the first defense barrier function to exogenous substances. However, the underling mechanisms about DON-induced intestinal toxicity remain poorly understood. Here, DON poisoning models of IPEC-J2 cells was established to explore adverse effect and the potential mechanism of DON-induced enterotoxicity. Results showed that DON exposure destroyed IPEC-J2 cells morphology. Results showed that DON exposure destroyed IPEC-J2 cells morphology. Intestinal epithelial barrier injury was caused by DON with increasing LDH release, decreasing cell viability as well decreasing tight junction protein expressions (Occludin, N-Cad, ZO-1, Claudin-1 and Claudin-3). Moreover, DON caused mitochondrial dysfunction by opening mitochondrial permeability transition pore and eliminating mitochondrial membrane potential. DON exposure upregulated protein and mRNA expression of mitochondrial fission factors (Drp1, Fis1, MIEF1 and MFF) and mitophagy factors (PINK1, Parkin and LC3), downregulated mitochondrial fusion factors (Mfn1, Mfn2, except OPA1), resulting in mitochondrial dynamics imbalance and mitophagy. Overall, these findings suggested that DON induced tight junction dysfunction in IPEC-J2 cells was related to mitochondrial dynamics-mediated mitophagy.

T-2 Toxin Caused Mice Testicular Inflammation Injury via ROS-Mediated NLRP3 Inflammasome Activation.

T-2 toxin treatment causes male reproduction system dysfunction, although the exact mechanism remains unclear. In this research, male Kunming mice and TM4 cells were treated with varying concentrations of the T-2 toxin for evaluating the adverse effect of T-2 toxin on male reproductive function. MCC950 or NAC was used to block NLRP3 inflammasome activation and eliminate reactive oxygen species (ROS) accumulation in the TM4 cell, respectively. The results showed that: (1) T-2 toxin caused testicular atrophy, destroyed the microstructure and ultrastructure of the testis, and caused sperm deformities; (2) T-2 toxin increased the content and gene expressions of TNF-α and IL-6 and decreased the IL-10 content and gene expression, causing testis and TM4 cell inflammatory injury; (3) T-2 toxin activated NLRP3 inflammasome in the testis and TM4 cells and caused ROS accumulation in the testis; (4) suppressing NLRP3 inflammasome activation using 20 nM MCC950 alleviated the TM4 cell inflammatory damage caused via the T-2 toxin; nevertheless, 20 nM MCC950 did not reduce ROS accumulation in TM4 cells; and (5) NAC relieved the inflammatory damage in TM4 cells by inhibiting NLRP3 inflammasome activation. Taken together, T-2 toxin caused testicular inflammation injury through ROS-mediated NLRP3 inflammasome activation, resulting in male reproductive dysfunction.

Low Prevalence of Toxoplasma gondii in Dogs From Central China.

Background: Toxoplasma gondii can infect almost all warm-blooded animals, including humans and dogs. Humans can become infected with T. gondii by petting dogs that have eaten or contacted infected cat feces. The aim of this study was to evaluate T. gondii infections in dogs from central China. From 2015 to 2021, a total of 536 dog samples (195 fecal, 81 hearts, and 260 serum samples) from Henan Province were collected. Heart juice or serum samples (n = 341) were tested for T. gondii antibodies using the modified agglutination test (MAT). Fresh myocardium (n = 6) and blood (n = 2) samples were bioassayed in mice. Results: The present study showed that 4.40% (15/341) of the dogs were seropositive for T. gondii by MAT (cut-off, 1:25) and 4.10% (8/195) of dog feces contained T. gondii DNA. No T. gondii DNA was found in any myocardium (n = 81) or blood (n = 2) samples. The viable T. gondii strain was not isolated from any myocardium or blood samples (n = 8). Compared to the prevalence of T. gondii antibodies in dogs sampled from 2015 to 2018, the prevalence significantly declined from 2020 to 2021 (P < 0.05). Gender and age were not risk factors for dogs infected with T. gondii in this study. However, compared to other sources, dogs from Zhoukou City (close to the Yellow River) or from pet shops showed significantly higher prevalence for T. gondii (P < 0.05). Conclusion: A total of 4.29% dogs were infected by T. gondii (23/536, 8 of 195 fecal samples, 2 of 260 serum, and 13 of 81 heart juice samples). This is the first survey of T. gondii infection in dog feces from China. Dogs were exposed to T. gondii, and they could act as mechanical transmitters of T. gondii.

Toxoplasma gondii in lambs of China: Heart juice serology, isolation and genotyping.

Toxoplasmosis is one of the most common foodborne diseases in the world. The objective of this study was to determine Toxoplasma gondii infection in lambs from Henan province, China. A total of 166 lamb hearts were collected from 2017 to 2019. T. gondii infection was determined by the Modified Agglutination Test (MAT) using heart juice of lambs. 11 isolates (TgSheepCHn3 - TgSheepCHn13) were obtained from samples with MAT titers ≥1:100. The rate of T. gondii isolation increased with antibody titer against T. gondii (P < 0.05). No isolate was obtained from samples with titer 1:25 and 1:50, suggesting the cut-off titer for MAT is better set at 1:100. With cut-off value of 1:100, IgG antibodies to T. gondii were found in 25.3% (42/166) of the lambs by MAT. T. gondii parasite was not found in IHC and HE-stained tissue sections of lamb hearts (0/166). Sixty-seven heart tissues with ≥1:25 MAT titers were subjected to acid pepsin digestion and detected T. gondii by PCR. Only 7.5% (5/67) of DNA amplified products were found in heart tissues by the primer TOX5/TOX8. Brain tissue cysts were observed in all mice infected with the 11 isolates at day 60 post infection, suggesting these isolates are non-lethal to mice. PCR-RFLP analysis revealed that 7 isolates belonged to ToxoDB#2, 4 isolates belonged to ToxoDB#4. This is the first isolation of ToxoDB#2 and ToxoDB#4 from lambs in China. Interestingly, none of these isolates belongs to the ToxoDB#9 that is common in China. Our results suggest that the genetic diversity and population structure of T. gondii from China maybe more abundant and magical than previous speculation.

Toxoplasma gondii in four captive kangaroos (Macropus spp.) in China: Isolation of a strain of a new genotype from an eastern grey kangaroo (Macropus giganteus).

Marsupials are highly susceptible to Toxoplasma gondii infection. Here, we report T. gondii infection in four kangaroos from a zoo in China. Kangaroos were imported into China in 2000 and were since bred in zoo. In 2017-2018, four kangaroos died due to respiratory system disease or injury. The bodies were submitted to the laboratory to test for T. gondii infection. Antibodies to T. gondii were found in 75% (3/4) of the kangaroos via the modified agglutination test with the cut-off 1:25. Cysts were observed in the histopathological sections of tongue and diaphragm or squashes of fresh myocardium in two kangaroos. These cysts were confirmed as T. gondii by immunohistochemical staining and molecular biological analysis. One viable T. gondii strain was isolated from one kangaroo and designated as TgRooCHn1. DNA from T. gondii tachyzoites obtained from cell culture was characterized by 10 PCR-RFLP markers and the virulence genes ROP5 and ROP18. The genotype of this isolate did not match with any known genotypes; it was designated as ToxoDB#292. The virulence of TgRooCHn1 (104 tachyzoites) was non-lethal to mice, and it formed tissue cysts. To our knowledge, the present study is the first isolation of ToxoDB#292 strain from kangaroo. Improvemets for captive settings were initiated, including greater attention being paied to birds and stray cats, fed frozen meat for carnivores.

High prevalence of Sarcocystis spp. infections in cattle (Bos taurus) from central China.

Myocardium and diaphragm samples of cattle (n = 521) from HeNan Province (China) were screened for Sarcocystis sarcocysts by histological examination, pepsin digestion, and molecular assays. Morphology and molecular assays were used for identification. The prevalence of Sarcocystis infection in cattle was 41.5% (216/521). Histological examination identified sarcocysts in the myocardium (49.4%, 200/405) and diaphragm (13.8%, 16/116) of cattle. Two species were identified, namely S. cruzi (41.3%, 215/521) and S. hominis (0.2%, 1/521). The findings of the present study indicate a high prevalence of S. cruzi infection in cattle from central China.

Antibody Detection, Isolation, Genotyping, and Virulence of Toxoplasma gondii in Captive Felids from China.

The felids are the only definitive hosts of Toxoplasma gondii, which could excrete oocysts into the environment and provide an infection source for toxoplasmosis in various warm-blooded animal species, particularly the captive felids that live close to human communities. The infection rate of the captive felids is a perfect standard in detecting the presence of Toxoplasma gondii oocysts in the environment. In this study, sera or tissue samples from zoo (1 young tiger, 2 adult tigers, 6 young lions), farm (10 masked palm civets), and pet hospital (28 cats) from Henan Province (China) were collected. The sera (n = 47) were tested for immunoglobulin G (IgG) antibodies against T. gondii by using modified agglutination test (MAT), whereas the hearts tissue (n = 40) were bioassayed in mice to isolate T. gondii strains. The genotype was distinguished by using PCR-RFLP of 10 loci (SAG1, SAG2, SAG3, GRA6, BTUB, L358, c22-8, PK1, c29-2, and Apico). The detection rate for the T. gondii antibody in captive felids was 21.3% (10/47). One viable T. gondii strain (TgCatCHn4) was obtained from a cat heart tissue, and its genotype was ToxoDB#9. The oocysts of ToxoDB#9 were collected from a T. gondii-free cat. The virulence of TgCatCHn4 was low and no cysts were detected in the brain of mice at 60 days post-inoculation. The finding of the present study suggested a widespread exposure of T. gondii for felids in Henan Province of central China, particularly those from the zoological gardens and homes. ToxoDB#9 was the predominant strain in China. Preventive measures against T. gondii oocyst contamination of various components of the environment should thus be implemented, including providing pre-frozen meat, well-cooked cat food, cleaned fruits and vegetables, monitoring birds and rodents, inactive T. gondii oocysts in felids feces, and proper hygiene.

Chicken intestine defensins activated murine peripheral blood mononuclear cells through the TLR4-NF-kappaB pathway.

Defensins serve as alarm signals in mobilizing the immune system and activating the innate and adaptive immune responses. In order to investigate whether avian defensins could activate monocytes of another species, and whether chicken defensins could modulate or amplify the adaptive immune responses of murine through the TLR-NF-kappaB pathway, the relationship between the chicken intestinal defensin AvBD13 and TLR4 in murine peripheral blood mononuclear cells (PBMCs) was explored in vitro. Monocytes were stimulated with AvBD13 (1 microg/mL). The levels of NF-kappaB p65, CD80, CD86, IL-12 and IFN-alpha were measured by immunohistochemical analysis of the cells or enzyme-linked immunosorbent assay (ELISA), and the TLR4 levels in monocytes were measured by flow-cytometry. We found that AvBD13 can activate NF-kappaB, induce the inflammatory cytokines IL-12 and IFN-alpha, and upregulate costimulatory molecules like CD80 and monocyte proliferation, which was clearly inhibited by the anti-TLR4 antibody. TLR4 expression was rapidly downregulated in the presence of AvBD13. AvBD13 could modulate monocytes directly and serve as an endogenous ligand for TLR4 and upregulate costimulatory molecules and monocyte proliferation. Thus, TLR4 is involved in AvBD13-mediated activation of adaptive immune responses.