Oxfendazole Nitazoxanide combination in experimental neurocysticercosis - Anti-inflammatory and cysticidal effects

Neurocysticercosis (NCC) is a parasitic infection caused by the larval stage of the pork tapeworm, Taenia solium. The complications of NCC include seizures, headaches, cognitive impairment, and focal neurological deficits. In addition to antiparasitic drugs and surgery, the management of NCC includes the use of corticosteroids to reduce inflammation and control symptoms. The traditional treatment with albendazole and praziquantel has not been altered over 30 years and present several side effects. There are other anti-helminthic drugs such as oxfendazole and nitazoxanide that may show efficacy in NCC treatment. The aim of this study was to determine the histopathologic aspects of experimental NCC after in vivo treatment with the combination of oxfendazole and nitazoxanide. Balb/c mice were infected with T. crassiceps cysticerci and divided into groups of 10 animals each that received a single dose through gavage as follows: group treated with NaCl 0.9% (control group); group treated by monotherapy of the anti-helminthic drugs, 30 mg/kg in single dose of oxfendazole (OXF) or nitazoxanide (NTZ); and groups treated with the combination of the drugs (OXF/NTZ group). Macroscopic and microscopic analysis were performed. There was greater presence of final stage cysticerci after treatment. The microscopic analysis of the general pathological processes showed that the monotherapy with all treatment groups induced higher perivasculitis than what was observed in the control group. In contrast, the combination treatment showed a lower observation of PMN and MN inflammatory infiltration in comparison to the other treatments and to the control one. These results show that indeed the association of benzimidazole derivatives which present both anti-helminthic and anti-inflammatory properties with other cysticidal drugs are beneficial for the NCC treatment in which the aim is to destroy parasite without inducing inflammatory damage in the brain tissue.

Oxfendazole induces protein catabolism and gluconeogenesis in experimental neurocysticercosis

Neurocysticercosis (NCC) is an endemic public health disease of the central nervous system highly related to epilepsy and seizures. Taenia crassiceps is an experimental model used for NCC and biochemical studies of the host-parasite relationship. For the past 50 years the NCC therapeutic treatment is performed with albendazole (ABZ) and praziquantel which opens a gap for new therapies due to parasitic resistance and other adverse effects of the drugs. Oxfendazole (OXF) is an albendazole derivative with efficacy against tissue cestodes of veterinary importance. The aim of this study was to determine the metabolic impact of OXF on T. crassiceps cysticerci intracranially inoculated in Balb/C mice. The animals were intracranially inoculated with T. crassiceps cysticerci and 30 days later received single dose oral treatment of OXF, ABZ and NaCl 0.9% (control group). The metabolic impact was quantified through the detection of metabolites from glycolysis, anaerobic fermentation of lactate and propionate, tricarboxylic acid cycle, protein catabolism, fatty acids oxidation. The differences observed in the concentrations of metabolites from the OXF treated group showed that the drug induced gluconeogenesis, increase in protein catabolism, fatty acids oxidation and propionate fermentation in comparison to the ABZ and control treated groups. In conclusion, OXF induced greater metabolic impact in T. crassiceps cysticerci than the standard NCC treatment, ABZ, showing that it may represent an alternative drug for its treatment.

Intraperitoneal and intracranial experimental cysticercosis present different metabolic preferences after treatment with isolated or combined albendazole and nitazoxanide

Cysticercosis is a zoonotic public health issue especially severe when the parasite is in the central nervous system although it may be found all over the human organism. Taenia crassiceps cysticerci inoculated in mice is the experimental model used to study cysticercosis. The most used cysticercosis treatment is with albendazole (ABZ). Nitazoxanide (NTZ) has been experimentally tested against this parasite. Metabolic analysis has been used to determine drugs impact on the parasite. The aim of this study was to determine the in vivo metabolic impact of the ABZ-NTZ combination in T. crassiceps cysticerci inoculated in mice peritoneal and intracranial cavities. Mice were experimentally inoculated with T. crassiceps cysticerci in the intraperitoneal cavity or in the intracranial one. Thirty days after the infection they were treated with NaCl 0.9% (control group), 50 mg/kg of ABZ, 50 mg/kg of NTZ or 50 mg/kg of NTZ and ABZ (ABZ/NTZ combination). 24 h after treatment the animals were euthanized and the cysticerci analyzed through high performance chromatography and spectrophotometry in order to detect the glycolytic, mitochondrial and protein catabolism pathways. The intracranial parasites used more intensely the homolactic fermentation while the intraperitoneal ones presented a greater use of the mitochondrial pathways and protein catabolism. Regarding the glycolytic pathways, it was possible to observe a significant impact induced by the drugs used, both isolated or in combination. It was possible to detect an increase in the fumarate reductase pathway after the drugs exposure and no impact in the protein's catabolism. Therefore, the cysticerci showed different uses of metabolic pathways regarding the site of inoculation due to the availability of nutrients inherent of each environment. This study showed the parasite metabolic resilience and capability of use of different biochemical pathways in order to ensure survival in spite of a hostile environment.

IgG Avidity in Samples Collected on Filter Paper: Importance of The Early Diagnosis of Congenital Toxoplasmosis

OBJECTIVE

 The purpose of the present study is to standardize and evaluate the use of the immunoglobulin G (IgG) antibody avidity test on blood samples from newborns collected on filter paper to perform the heel test aiming at its implementation in ongoing programs.

METHODS

 Blood samples from newborns were collected on filter paper simultaneously with the heel prick test. All samples were subjected to immunoglobulin M IgM and IgG enzyme-linked immunosorbent assays (ELISA). Peripheral blood was collected again in the traditional way and on filter paper from newborns with high IgG levels (³3). Three types of techniques were performed, the standard for measuring IgG in serum, adapted for filter paper and the technique of IgG avidity in serum and on filter paper. The results of the avidity test were classified according to the Rahbari protocol.

RESULTS

 Among the 177 samples, 17 were collected in duplicate from the same child, 1 of peripheral blood and 1 on filter paper. In this analysis, 1 (5.88%) of the 17 samples collected in duplicate also exhibited low IgG avidity, suggesting congenital infection. In addition, the results obtained from serum and filter paper were in agreement, that is, 16 (94.12%) samples presented high avidity, with 100% agreement between the results obtained from serum and from filter paper.

CONCLUSION

 The results of the present study indicate that the avidity test may be another valuable method for the diagnosis of congenital toxoplasmosis in newborns.

Identification of Biomarkers for Diagnosis and Prognosis of Congenital and Acute Toxoplasmosis

BACKGROUND

The diagnosis of congenital toxoplasmosis can be inconclusive in many cases. Despite the several serological tests developed, the literature on biomarkers that can assist in the diagnosis of congenital an acute toxoplasmosis is limited. The objective of this study was to analyze the immunoreactive profile of Toxoplasma gondii protein bands with the potential to be biomarkers for diagnosis and prognosis of congenital and acute toxoplasmosis.

METHODS

Peripheral blood samples from women of childbearing age and/or pregnant women diagnosed with acquired toxoplasmosis as well as from congenitally infected children were selected and submitted to immunoblotting for analysis of the immunoreactive bands profile by immunoglobulin G (IgG) antibodies.

RESULTS

When comparing the immunoreactive bands profile for antibodies present in samples from different groups and subgroups, the 150, 18.5, and 16.96-kDa bands were more immunoreactive with the antibodies present in serum samples from the acquired infection group. The 343, 189, 150, 75, and 42-kDa bands showed more chance to be detected by the symptomatic congenital infection subgroup samples, while the 61, 50, and 16.96-kDa bands were significantly immunoreactive with the acute infection subgroup samples.

CONCLUSIONS

The identification of these potential biomarkers can assist in early diagnosis and treatment of congenital toxoplasmosis.

Molecular characterization of Toxoplasma gondii isolates from free-range chickens reveals new genotypes in Goiânia, Goiás, Brazil

The aim of this study was to evaluate the genotypic characteristics of Toxoplasma gondii isolated from free-range chickens in the metropolitan area of Goiânia, Goiás, in Brazil's central-west region. The seroprevalence rate was found to be 96%, according to an indirect hemagglutination assay. Brain and heart samples were processed by peptic digestion for a mice bioassay. The tissues were homogenized and the resulting samples were subjected to polymerase chain reaction (PCR), which revealed that 64% of them contained the parasite's DNA. The mice bioassay revealed 15 isolates, 8 of them tachyzoites isolates from the peritoneal lavage and 7 from brain cysts. T. gondii genotypes were determined through PCR-RFLP, using the following markers: SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1, alt. SAG2, Apico and CS3. Three genotypes were identified, inclued ToxoDB #65, and the other two are not yet described in the literature. Hence, we conclude that the isolates obtained from the metropolitan area of Goiânia showed relatively low genetic diversity.

Basic heel prick test: inclusion of screening, diagnosis and criteria for early confirmation of congenital infection by Toxoplasma gondii

Toxoplasma gondii can cross the placental barrier, causing fetal infection with potentially severe sequelae. The aim of this study was to evaluate whether the serological screening for toxoplasmosis should be included in the basic neonatal heel prick test in order to establish criteria for the confirmation and/or exclusion of the diagnosis of congenital infection in newborns treated at three public health units in the metropolitan region of Goiania, Goias State, Brazil. Blood samples were collected on filter paper from newborns and later, peripheral blood samples from the mothers and their respective children were obtained to confirm or exclude the diagnosis of suspected congenital infection, by means of an enzyme-linked immunosorbent assay (IgM and IgG) and a polymerase chain reaction assay. From a total of 1,159 blood samples collected on filter paper, 43.92% were reactive to IgG and 0.17% to anti-T. gondii IgM and IgG. One hundred and twenty-seven paired samples (mother and child) were collected following consensual protocols for peripheral blood collection. Results obtained from the filter paper and peripheral blood of the newborns were 90.55% concordant. A comparison of the mother and child blood test results showed agreement regarding the detection of IgG in 90.48% of the samples. The parasite DNA was detected in the peripheral blood of one child. In view of the results obtained in this study, the inclusion of the serological screening for toxoplasmosis in the newborn heel prick test proved to be effective for the early detection of congenital T. gondii infection.

Nursing infant with acquired toxoplasmosis in the first months of life - a case report

Toxoplasmosis is caused by Toxoplasma gondii and the probability of this infection occurring in the first months of life is usually low because its transmission is related to eating habits. A 6-month-old nursing infant was diagnosed with acute toxoplasmosis, which was identified through anti- T. gondii IgA, IgM and low-avidity IgG serologic assays, polymerase chain reaction (PCR) and mouse bioassay test although its mother was seronegative. This serological divergence between mother and child led us to interview the mother regarding epidemiological factors. During this interview, she reported that she had given her 2-month-old baby a piece of undercooked beef to suck on. After some time, the baby presented fever and cervical lymphadenitis. This report emphasizes the importance of serological surveys of toxoplasmosis in nursing infants presenting with fever and lymphadenitis, in view of the possible acquisition of toxoplasmosis in the first months of life.