Corticosteroids Opportunist Higher Toxoplasma gondii Brain Cysts in Latent Infected Mice

Association between toxoplasmosis and autoimmune rheumatic diseases in Egyptian patients

PURPOSE

To explore the association between T. gondii and autoimmune rheumatic diseases (ARDs).

METHODS

This study involved 82 patients with ARDs: 44 rheumatoid arthritis (RA), 28 systemic lupus erythematosus (SLE), and 10 systemic sclerosis (SSc) and 61 age- and sex-matched controls. Sociodemographic, clinical, and laboratory data were collected, and disease activity was assessed. Exposure to toxoplasmosis risk factors was investigated. Serological tests for anti-Toxoplasma IgM and IgG antibodies were assessed using ELISA.

RESULTS

In SLE patients, a significant difference of T. gondii IgM versus controls was detected (P=.03). In RA and SLE patients, T. gondii IgG showed a significant difference versus controls (34 (77.3%) P=.001 and 18 (64.3%) P=.03, respectively). There was no significant difference in SSc versus controls. Fetal congenital anomalies displayed a significant difference in IgM seropositive compared to seronegative patients (P=.04). Cat exposure showed a significant difference between IgM and IgG seropositive versus seronegative patients (12 (80.0%) P=.02 and 34 (59.6) P=.04, respectively). There was no significant difference in seropositive patients regarding history of abortion, neuro-psychiatric manifestations, disease activity parameters (ESR, CRP), or different regimens of medications.

CONCLUSION

Toxoplasma IgM seropositivity is associated with SLE patients. T. gondii IgG seropositivity is associated with both RA and SLE patients. However, Toxoplasma seropositivity had no association with SSc patients. An association between fetal congenital anomalies and IgM seropositivity was demonstrated. A linkage between cat exposure as a risk factor and toxoplasmosis was suggested among ARD patiants. Exploration of impact of toxoplasmosis on ARDs is a necessity through randomized controlled trials.

Type-1 diabetes mellitus down-regulated local cerebral glial fibrillary acidic protein expression in experimental toxoplasmosis

Cerebral toxoplasmosis is an opportunistic infection, occurring mostly in immunosuppressed patients due to the reactivation of latent Toxoplasma cysts. The cerebral comorbidity in diabetic patients tends to intensify the burden of pathogenic infection within the brain. The aim of this work was to study the effect of cerebral toxoplasmosis in experimentally infected hyperglycemic mice, on histopathology and glial fibrillary acidic protein (GFAP) expression, compared to normoglycemic mice at different time intervals. Vasculopathy was exclusively observed in diabetic groups, with features of increased severity during Toxoplasma infection. Gliosis was observed in diabetic groups, while hyperactive astroglial activity was detected in normoglycemic groups, especially at 6 weeks of infection. GFAP expression showed significant up-regulation in normoglycemic mice at 6 weeks of infection (40.03 ± 1.41) afterwards, it decreased to 22.22 ± 3.14 at 12 weeks which was statistically insignificant to the normal level, possibly indicating the successful Toxoplasma stage transformation (to bradyzoite), thereby limiting the infection within the brain. In hyperglycemic infected groups, GFAP was significantly down-regulated, in both acute and chronic phases of infection, most likely indicating failure of stage transformation and infection limitation. This may expose those vulnerable groups to the risk of dissemination, resulting in life-threatening diffuse encephalitis. The current study emphasized the importance of rapid diagnosis of Toxoplasma infection in diabetic subjects, and highlighted the value of using GFAP as a neurological indicator of disease progression in those comorbid cases.

Immunological, histopathological, and ultrastructural evidence of steroid-induced reactivation of chronic murine toxoplasmosis

We developed a model of steroid-induced reactivation of chronic murine toxoplasmosis to mirror similar effects of steroids or other immunosuppressants in infected humans. Immunological, histopathological, and ultrastructural parameters were reported. Prior to steroid administration, mice were infected with 10 cysts of the Me49 strain of Toxoplasma gondii. Mice were treated with dexamethasone (DXM, 2.5 mg/kg/day in drinking water), alone or combined with Solu-Cortef (SOLU, 50 mg/kg by subcutaneous injection 3 times a week) for 7 weeks or left untreated as control. Histopathological changes and ultrastructural effects of steroids on the course of chronic toxoplasmosis were recorded. By electron microscopy, the brains of infected combined treated mice showed an increase in number of tachyzoites and bradyzoites, degeneration, and necrosis of neural cells and hydropic degeneration besides the observed rupture of toxoplasma cysts releasing free tachyzoites in brain tissue. DXM+SOLU-combined treatment also significantly increased mortality, mean brain cyst count as compared to infected untreated mice (P = .01 and). Moreover, 3/12 (25%) treated animals developed clinical signs of toxoplasmic encephalitis. This simple model of drug-induced reactivation of chronic toxoplasmosis permits investigation of host-parasite interaction and may be used for the evaluation of chemotherapeutics in immunocompromised infected patients.

Seroprevalence, isolation, molecular detection and genetic diversity of Toxoplasma gondii from small ruminants in Egypt

Toxoplasmosis is an infectious zoonotic disease caused by protozoan Toxoplasma gondii. Detection of T. gondii infection with touchy and particular strategies is a key advance to control and prevent toxoplasmosis. Genotyping can explain the virulence, epidemiology and setting up new methodologies for diagnosis and control in human and animals. The point of this study was to assess the seroprevalence of T. gondii in sheep and goat in Egypt and to comprehend the genetic variety of T. gondii isolates circling in Egypt. Blood samples were gathered from 113 ewes and 95 she-goats from three Egyptian governorates (Cairo, Giza and Al-Sharkia). Also blood and tissue samples were gathered from 193 sheep and 51 goats from Cairo and Giza abattoirs. All samples were assayed serologically utilizing ELISA and OnSite Toxo IgG/IgM Rapid test cassettes (OTRT) tests and the tissue samples of the seropositive animals were digested and microscopically examined then bio-assayed in mice as viability test. All the T. gondii isolates undergo molecular identification using PCR and genotyped utilizing nPCR/RFLP analysis of SAG2 gene. The total seropositivity of live sheep and goat was 47.15 and 39.2% utilizing ELISA and OTRT respectively. Concerning abattoirs, seropositivity, positive microscopic examination, mice viability from sheep samples were 47.1%, 37.3% and 44.1% respectively while that of goats were 45.5%, 33.3% and 48.6% respectively. Eighteen T. gondii isolates were affirmed utilizing PCR. Genotyping confirmed 10 isolates (55.5%) as type II, 6 (33.3%) as type III and 2 (11.1%) as atypical genotypes. Type II and III are the genotypes mostly circling among small ruminants in Egypt and this is most significance for the public health in Egypt.

Activities of anti-Toxoplasma drugs and compounds against tissue cysts in the last three decades (1987 to 2017), a systematic review

Currently, there is no approved therapy that can eradicate Toxoplasma gondii tissue cysts, which are responsible for chronic infection. This systematic review was performed to assess drugs or compounds that can be used as anti-T. gondii tissue cysts in vitro and in vivo. English electronic databases (i.e., PubMed, Science Direct, Scopus, Google Scholar, and Web of Science) were systematically searched for articles published up to 2017. A total of 55 papers published from 1987 to 2017 were eligible for inclusion in this systematic review. Among the drugs, atovaquone and azithromycin were found effective after long-term inoculation into mice; however, clinical cases of resistance to these drugs have been reported. Also, FR235222, QUI-11, tanshinone IIA, and hydroxyzine were shown to be effective against Toxoplasma cysts, but their effectiveness in vivo remains unknown. Additionally, compound 32, endochin-like quinolones, miltefosine, and guanabenz can be used as effective antiparasitic with the unique ability to reduce brain tissue cysts in chronically infected mice. Importantly, these antimicrobial agents are significant criteria for drug candidates. Future studies should focus on the biology and drug susceptibility of the cyst form of T. gondii in chronic toxoplasmosis patients to find more effective strategies that have sterilizing activity for eliminating T. gondii tissue cysts from the host, preventing disease relapse and potentially shortening the required duration of drug administration. Graphical abstract.

New approach to differentiate primary from latent Toxoplasma gondii abortion through immunoglobulin and DNA interpretation

BACKGROUND

Toxoplasma gondii is an acute or latent zoonotic abortifacient human protozoan. Women may be aborted due to recent or latent infection during pregnancy or order to flare up of the dormant bradyzoites to acute tachyzoites (latent opportunistic relapse).

AIMS

1) to validate the interpretation of IgM and IgG immunoglobulins seromonotoring with DNA comparative results in differentiating recent from latent T. gondii abortion.

METHOD

Blood with the corresponding placental or uterine wash samples were collected from 73 aborted Egyptian women from Cairo and Giza labour wards. Patients aborted in any of the phases (Ph-1, Ph-2, Ph-3 and Ph-4 were corresponding to abortion at the 1st, 2nd and 3rd trimesters plus females who gave birth with congenital anomalies), respectively. All aborted patients were assayed serologically by Enzyme Linked Immunosorbent Assay (ELISA) for IgM and IgG titers and the compatible DNA from placenta and uterine wash tissues by conventional Polymerase Chain Reaction (PCR) specific for T. gondii.

RESULTS

Sero-positive aborted women were 50.7% by ELISA versus 37% by PCR. Not all T. gondii sero-positive aborted women were having T. gondii DNA or harboring compatible placental T. gondii cysts. This denotes that immunoglobulins alone are insufficient criteria for confirming toxoplasma abortion.

CONCLUSION

Immunoglobulins with DNA comparative results can possibly differentiate recent from latent T. gondii abortion at higher precision. We recommend the need for routine monitoring of T. gondii i.e. (pre-, during and post-delivery).