New prevalence surveillance of Toxoplasma gondii among rodents and stray cats by ELISA avidity and nested PCR methods, Northeast of Iran

Abstract

Rodents and stray cats are the sources of many parasitic infections including T. gondii, for other animals and human. Toxoplasmosis has a wide range of laboratory factors in its intermediate and definite hosts. Regarding the importance of rodents and stray cats as the hosts that spread the Toxoplasma gondii, it is necessary to obtain comprehensive information about these animals in the life cycle of T. gondii. The objective was to investigate the new prevalence of toxoplasmosis among target animals in Iran, using GRA6 gene in combinacion with ELISA avidity. In this study, 286 rodents and 210 stray cats were collected and their heart tissues extracted to obtain DNA, blood samples and IgG Ab of T.gondii parasite. We detected the positive tissue samples in our study by the nested-PCR method. Then, we examined T. gondii IgG ELISA avidity for assessment of toxoplasmosis among rodents and stray cats. This study, was conducted in January to March 2017, based on the prevalence study. The findings revealed that 246/286 (86.01%) of rodents and 180/210 (85.71%) of stray cats were positive by IgG ELISA avidity methods. moreover, 68 rodents samples and 38 stray cats samples were positive concerning the GRA6 Toxoplasma gene; and these positive samples were at intermediate levels for IgG avidity. We concluded that the new prevalence of toxoplasmosis among rodents and stray cats was at high levels, using the serologic method in Northeast of Iran and the results of quantitative ELISA avidity were as the same as those of the nested-PCR for detecting recent toxoplasmosis in these hosts.

Seroprevalence and Molecular detection of Toxoplasma gondii Infections in Rodents and Cats in Mbeya District, Tanzania.

“…Molecular detection of GRA 6 gene in some of the seropositive rodents and seronegative cats confirms the T. gondii infection. The results reflecting fewer molecular confirmations of T. gondii infections in seropositive rodents and cat samples are in line with those obtained in study conducted in Iran (Bahadori et al, 2019).…”

“…The infection is wide spread, although at varying proportions. For instance, (Bahadori et al, 2019;Ahmad et al, 2012;Gryzbek et al, 2021) in Iran, Pakistan and Poland respectively reported higher seroprevalence while Mgode et al, (2014), Defeo et al, (2002) and Brouat et al, (2018) in Morogoro, Rhode Island and Senegal respectively registered lower seroprevalence rates. The observed variations in seroprevalence rates in different areas could be a function of variations in climatic and ecological properties such as humidity, soil topography, ambient temperature and exposure to ultraviolet rays in the studied areas.…”

“…This has been similarly claimed by Gondim et al, (2017) in Cambridge who reported that there is cross reactivity among cyst forming coccidian parasites including T. gondii, Hammondia spp, Neospora spp, Sarcocystis spp, and Besnoitia besnoiti. The molecular results could have also been affected by the stage of parasites life cycle as the GRA 6 gene is more abundant in the bradyzoites unlike tachyzoites stage (Bahadori et al, 2019). Additionally, in previous infection where parasites have been cleared but antibodies persist for longer periods may also influence the relatively lower molecular detection since the study was detecting immunoglobulins (IgG's) which persist longer in the body and are produced in the delayed response (Elmore et al, 2010).…”

Review on diagnosis and molecular characterization of Toxoplasma gondii in humans and animals

“…The B1 gene is primarily used for the identification of T. gondii with this type of PCR (Botein et al, 2019;Nakashima et al, 2020;Ngui et al, 2020). However, the Me49, GRA6, and Rep529 genes have also been used as targets (Mousavi et al, 2016;Bahadori et al, 2019;Shahbazi et al, 2019). It is noteworthy that both the B1 and REP 529 genes of T. gondii show more sensitivity and specificity in nested PCR than conventional PCR (Jones et al, 2000;Fallahi et al, 2014b).…”