Serological and molecular diagnosis of Toxoplasma gondii in patients with schizophrenia

Toxoplasma gondii infection by serological and molecular methods in schizophrenia patients with and without suicide attempts: An age-sex-matched case-control study

INTRODUCTION

The opinion that latent Toxoplasma gondii infection is having a broadly asymptomatic projection has now been interrogated, in specific due to the echoed association between the latent infection and an elevated incidence of schizophrenia or even suicide attempts. Notwithstanding conducted studies aimed to understand this feasible link are restricted.

METHODS

In the present case-control study, we focused to illuminate the relationship between the serological and molecular presence of T gondii and schizophrenia with or without the suicide attempts by comparing it with healthy individuals. A total of 237 participants (117 in schizophrenia and 120 in healthy control) were included in this study.

RESULTS

Overall, latent T gondii infections were found statistically higher in 63 (53.8%) of the 117 patients with schizophrenia and in 33 (27.5%) of the 120 controls (P < .001). In schizophrenia patients, seroprevalence T gondii was again found to be statistically higher in suicide attempters (59.6%), compared with no history of suicide attempts (48.3%; P < .05). The molecular positivity rate of T gondii DNA was higher in the schizophrenia group, compared with the healthy control group (P < .05), whereas the history of suicide attempts was not statistically associated (P = .831) with T gondii DNA positivity by polymerase chain reaction.

CONCLUSION

This case-control study enlightens additional demonstration to the belief that T gondii infection would be an underlying component for the pathophysiology of schizophrenia. Regardless of the clarity results of this study, this supposition warrants further endorsement.

First isolation of Toxoplasma gondii from rodents and stray cats in northeast of Iran

Toxoplasma gondii is a common coccidian parasite with stray cat family as definitive host, and a wide range of warm blooded animals and human as intermediate hosts. The objective of this study was to isolate T. gondii from rodents and stray cats in northeast of Iran. Genomic DNA was extracted from 30–50 mg of the rodents and stray cats’ tissue using phenol-chloroform extraction method. Using PCR-RFLP, the genes (SAG1, SAG3, GRA6, 18SrRNA) and sequencing method, the isolation of T. gondii from these hosts was determined. ELISA method was also used on serum samples to evaluate the IgG antibodies against T. gondii among the hosts. Out of 286 rodents and 210 stray cats tested, the DNA of T. gondii was detected in 68 and 38 samples, respectively. Nucleotide sequencing and phylogenetic analysis confirmed the RFLP results. It was also observed that dominant genotype of T. gondii in infected rodents and stray cats belonged to genotype 3. The results of this study indicated that rodent and stray cat hosts can play an important role in maintaining the Toxoplasma transmission cycle in the Golestan province.