Phenotypic and genotypic characterization of two Toxoplasma gondii isolates in free-range chickens from Uberlândia, Brazil.

The aim of this study was to determine the seroprevalence of Toxoplasma gondii infection in free-range chickens from Uberlândia, Minas Gerais state, Brazil, and characterize the genotypic and phenotypic features of two isolates of this parasite, considering the importance of these hosts in the epidemiology of toxoplasmosis. Serum samples from 108 free-range chickens were obtained from ten different districts, and submitted to the modified agglutination test (MAT) for the presence of anti-T. gondii antibodies, and brain and heart tissue samples from infected chickens were processed for mouse bioassay. An overall seroprevalence of 71·3% was found and antibody titres ranged from 16 to 4096. After confirmation of seropositivity by mouse bioassay, the determination of the T. gondii genotypes of two isolates was performed by PCR-RFLP, using primers for the following markers: SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, new SAG2, Apico and CS3. These T. gondii isolates, designated TgChBrUD1and TgChBrUD2, were obtained from heart samples of free-range chickens. The TgChBrUD1 isolate belonged to ToxoDB PCR-RFLP genotype 11 and the TgChBrUD2 isolate belonged to ToxoDB PCR-RFLP genotype 6. Both isolates demonstrated high virulence in a rodent model, with the TgChBrUD1 isolate able to induce brain cysts, in accord with its pattern of multiplication rates in human fibroblast culture. Taken together, these results reveal high prevalence of T. gondii infection in free-range chickens throughout Uberlândia, indicating an important degree of oocyst environmental contamination and the existence of considerable risk for T. gondii transmission to humans by consumption of free-range chicken as a food source.

Trophoblast-macrophage crosstalk on human extravillous under Toxoplasma gondii infection.

INTRODUCTION: The interaction between human extravillous trophoblasts and macrophages has an important role in implantation and placentation. However, any dysfunction in this communication system is associated with pregnancy pitfalls, and a Toxoplasma gondii infection can be a potential problem in this crosstalk. Therefore, the aim of this study was to assess the influence of infected macrophages on cytokine production and the incidence of apoptosis in T. gondii-infected extravillous trophoblast cells. METHODS: HTR-8/SVneo cells were treated with supernatant from macrophages infected or not by T. gondii (conditioned medium) in order to analyze apoptosis and cytokine production in comparison to uninfected control conditions. RESULTS: The IL-6 secretion by HTR-8/SVneo cells increased synergistically by treatment with conditioned medium and T. gondii infection. The apoptosis index of HTR-8/SVneo cells was also upregulated by treatment with conditioned medium and infection. In addition, a low expression of Fas/CD95 and a high soluble FasL release were observed during infection, although no significant change was observed in the proliferation of T. gondii. DISCUSSION: The parasite modulates the high apoptosis index in HTR-8/SVneo cells in order to favor its establishment inside its host cells. On the other hand, the conditioned medium from uninfected macrophages restores the apoptosis rates, although the effect of the infection seems to be stronger. In conclusion, our results showed that T. gondii infection in human extravillous trophoblasts is able to modulate the trophoblast-macrophage crosstalk.

Differential apoptosis in BeWo cells after infection with highly (RH) or moderately (ME49) virulent strains of Toxoplasma gondii is related to the cytokine profile secreted, the death receptor Fas expression and phosphorylated ERK1/2 expression.

INTRODUCTION: Alterations of apoptosis are commonly associated with pregnancy complications and abortion. Modulation of apoptosis is a relevant feature of Toxoplasma gondii infection and it is related to parasite strain types. The aim of the present study was to evaluate the possible factors that are involved in the differential apoptosis of BeWo cells infected with distinct T. gondii strain types. METHODS: Human trophoblastic cells (BeWo cell line) were infected with RH or ME49 strains, the cytokine production was measured and the phosphorylation of anti-apoptotic ERK1/2 protein was analyzed. Also, cells were treated with different cytokines, infected with RH or ME49 strain, and analyzed for apoptosis index and Fas/CD95 death receptor expression. RESULTS: ME49-infected BeWo cells exhibited a predominantly pro-inflammatory cytokine profile, whereas cells infected with RH strain had a higher production of anti-inflammatory cytokines. Also, the incidence of apoptosis was higher in ME49-infected cells, which have been treated with pro-inflammatory cytokines compared to cells infected with RH and treated with anti-inflammatory cytokines. Moreover, Fas/CD95 expression was higher in cells infected with either ME49 or RH strain and treated with pro-inflammatory cytokines compared to anti-inflammatory cytokine treatment. The phosphorylation of ERK1/2 protein increased after 24 h of infection only with the RH strain. CONCLUSION: These results suggest that opposing mechanisms of interference in apoptosis of BeWo cells after infection with RH or ME49 strains of T. gondii can be associated with the differential cytokine profile secreted, the Fas/CD95 expression and the phosphorylated ERK1/2 expression.

Trophoblast cells are able to regulate monocyte activity to control Toxoplasma gondii infection.

INTRODUCTION: Toxoplasma gondii is an intracellular parasite that causes severe disease when the infection occurs during pregnancy. Trophoblast cells constitute an important maternal-fetal barrier, with monocytes concentrating around them. Thus, interactions between trophoblasts and monocytes are important for maintaining a successful pregnancy, especially in cases of infection. This study aimed to evaluate the role of trophoblast cells (BeWo line) on monocyte (THP-1 line) activity in the presence or absence of T. gondii infection. METHODS: THP-1 cells were stimulated with supernatants of BeWo cells, previously infected or not with T. gondii, and then infected with parasites. The supernatant of both cells were collected and analyzed for cytokine production and T. gondii proliferation in THP-1 cells was determined. RESULTS: The results showed that after infection, the pattern of cytokines secreted by THP-1 and BeWo cells was characterized as a pro-inflammatory profile. Furthermore, supernatant of BeWo cells infected or not, was able to change the cytokine profile secreted by infected THP-1 cells, and this supernatant became THP-1 cells more able to control T. gondii proliferation than those that had not been stimulated. DISCUSSION: This effect was associated with secretion of interleukin (IL)-6 by the THP-1 cells and soluble factors secreted by BeWo cells, such as IL-6 and MIF. CONCLUSION: Together, these results suggest that trophoblast cells are able to modulate monocyte activity, resulting in the control of T. gondii infection and subsequent maintenance of pregnancy.

Azithromycin and spiramycin induce anti-inflammatory response in human trophoblastic (BeWo) cells infected by Toxoplasma gondii but are able to control infection.

Toxoplasma gondii is an important pathogen which may cause fetal infection if primary infection. Our previous studies have used human choriocarcinoma trophoblastic cells (BeWo cell line) as experimental model of T. gondii infection involving placental microenvironment. This study aimed to examine the effects of azithromycin and spiramycin against T. gondii infection in BeWo cells. Cells were treated with different concentrations of the macrolide antibiotics and analyzed first for cell viability using thiazolyl blue tetrazole (MTT) assay. As cell viability was significantly decreased with drug concentrations higher than 400 µg/mL, the concentration range used in further experiments was from 50 to 400 µg/mL. The number of infected cells and intracellular replication of T. gondii decreased after treatment with each drug. The infection induced up-regulation of the macrophage migration inhibitory factor (MIF), which was also enhanced in infected cells after treatment with azithromycin, but not with spiramycin. Analysis of the cytokine profile showed increase TNF-α, IL-10 and IL-4 production, but decreased IFN-γ levels, were detected in infected cells and treated with each drug. In conclusion, treatment of human trophoblastic BeWo cells with with azithromycin or spiramycin is able to control the infection and replication of T. gondii. In addition, treatment with these macrolides, especially with azityromycin induces an anti-inflammatory response and high MIF production, which can be important for the establishment and maintenance of a viable pregnancy during T. gondii infection.

Evaluation of vertical transmission of Toxoplasma gondii in Calomys callosus model after reinfection with heterologous and virulent strain.

Toxoplasma gondii is an obligate intracellular protozoan parasite that causes a variety of clinical syndromes, but the infection is severe in immunocompromised individuals and during pregnancy due to the possibility of transplacental transmission of the parasite causing congenital toxoplasmosis. Vertical transmission of the parasite usually occurs when females are primarily infected during pregnancy. Calomys callosus is resistant to T. gondii ME49 strain, which presents a moderate virulence and congenital disease occurs only during the acute phase of infection. The aim of this study was to determine whether vertical transmission occurs when females of C. callosus chronically infected with ME49 strain of T. gondii are reinfected with a highly virulent strain (RH, type I). Females were infected with cysts of the ME49 strain. On the 1st day of pregnancy, animals were reinfected with tachyzoites of the RH strain. In the 19th day of pregnancy, placentas and embryos were processed for morphological analysis, immunohistochemistry and for detection of the parasite by PCR and mouse bioassay. Morphological and immunohistochemical analyses revealed the presence of parasites only in placental tissues. Mouse bioassay results showed seroconversion only in mice that were inoculated with placental tissues. Also, T. gondii DNA was detected only in placental samples. Congenital toxoplasmosis does not occur in C. callosus females chronically infected with the moderately virulent ME49 strain of T. gondii and reinfected with the highly virulent RH strain, thus indicating that primary T. gondii infection before pregnancy leads to an effective long-term immunity preventing transplacental transmission to the fetus.

[Chondromyxoid fibroma of the thoracic spine: a case report and review of the literature]. / Fibroma condromixóide da coluna torácica: relato de caso e revisão da literatura.

A case of chondromyxoid fibroma (CMF) arising from the 5th right costovertebral junction and spreading into spinal canal causing spinal cord compression is presented. A myelotomography revealed a complete block at T5 level. The patient underwent a decompressive laminectomy with removal of an epidural tumor. This specimen was sent for pathological examination and interpreted as a CMF. The patient had a neurological improvement, post operative MRI revealed a spinal cord free of compression, and we decided on the follow up of the case. Two years later there was recurrence of the tumor. A posterolateral access by costotransversectomy was made and the lesion was resected. The patient had a neurological improvement which persists on the follow up (two years, at present). Clinical, radiologic and histologic findings, surgical management and recurrence are discussed. The pertinent literature is reviewed.