Evaluation of B1 gene and G529 repeated element as targets for molecular diagnosis of toxoplasmosis in pregnant and aborted women in Erbil

Toxoplasma gondii is a ubiquitous protozoan parasite that infect one-third of the world’s human population, and diagnosed mainly by serological methods that are impeded by insufficient sensitivity. Therefore, it becomes necessary to rely on either direct discovery of the parasite or DNA detection by polymerase chain reaction (PCR). This study aimed to find out the prevalence of toxoplasmosis among women in Erbil and to organize molecular tools for toxoplasmosis using PCR targeting B1 gene and G529 comparing with Enzyme-linked immunosorbent assay (ELISA). The study also aimed to evaluate placenta versus blood specimens in molecular diagnosis.

A cross sectional study carried out in Erbil city, from November 2015 to September 2016, including convenience samples of 350 women who attended the Maternity Teaching Hospital, and some Primary Health Centers in Erbil city. The subjects involved pregnant women with and without history of abortion, and women at labor room. Peripheral blood samples were collected. DNA was extracted and the B1 gene and G529 of T. gondii were amplified by PCR.

Out of 350 samples tested, 38(10.9%) and 81(23.1%) were seropositive for anti-toxoplasma IgM and anti-toxoplasma IgG, respectively, and 7(2%) for both IgG and IgM. PCR, targeting B1 gene and G529, revealed positive reactions in 92 (26.3%) and 41 (11.7%), respectively. In 40 placenta specimens collected from abortive and non-abortive women, 1 (5.56 %) and 5 (27.77 %) of abortive women, versus 1 (4.55 %) and 5 (22.73 %) of non-abortive women revealed positive reactions for B1 and G529, respectively. Statistically, there was no significant (P= 0.897, P= 0.533) differences among the studied genes in respect to detect toxoplasmosis in the blood of whether abortive or non- abortive women. PCR along with serology as a confirmatory test is insisted demand for definitive diagnosis of toxoplasmosis, and PCR targeting G529 being more efficient than B1 gene in the molecular diagnosis in placenta specimens. Although not all pregnancies with toxoplasmosis terminated adversely, maternal infection during pregnancy is a serious condition and early diagnosis on time and proper treatment can lead to healthy offspring