History of Medicine


An Open Access Journal

Molecular Characterization of the Toxoplasma gondii SAG-4 Gene in Cancer Patients in Kirkuk city

Amjad Ali Mohamed
M.Sc. Microbiology, Kirkuk Health Directorate, Iraq.
Neama Ali Ahmed
Ph.D. Biology- Parasitology, University of Kirkuk, College of science, Department of Biology/Iraq.
Muhannad Abdullah Al-Azzawy
Ph.D. Medical Microbiology, College of Medical Technology, AL-Kitab University. Kirkuk, Iraq.



Toxoplasma gondii (T. gondii) is a parasitic protozoan that can infect warm-blooded animals, including humans. Cats are the definitive host of T. gondii, meaning that they are the only animals in which the parasite can sexually reproduce.


The study aimed at molecular detection of the SAG4 gene of the Toxoplasma in cancer patients by real time PCR

Materials and methods

The study collected 240 samples from cancer patients and recorded information about each patient in a questionnaire from the period 1/11/2022 to 1/4/2023. The samples were kept at -20°C until they were examined using PCR. The DNA extraction kit used guanidine thiocyanate to break down cells and purify nucleic acids for amplification using RT-PCR. The PCR reaction was specific to the SAG-4 gene and monitored using fluorinated dyes and oligonucleotide probes. Positive samples showed curves during the amplification process, while negative samples showed a straight horizontal line. The study used an internal control and detected the presence of T. gondii DNA in the fluorinated HEX channel.


The results of the preliminary study showed that 26.25% (63) out of the total patient group of 240 examined had IgG antibodies to toxoplasmosis gondii, while these antibodies were not detected in the control group. On the other hand, the preliminary results of the study showed that patients carrying antibodies to the T. gondii parasite as a population of 75% (45) while the remaining 25% ( 15) were from villages, and The seroprevalence of T. gondii in the current study was not significantly associated with any of the sociodemographic characteristics of cancer patients The results of the current study showed that the majority of patients had received chemotherapy and radiation treatment 88.33% (53) while 11.67% (7) received hormonal treatments appropriate to the nature of the cancers they suffer from. The current study showed that 17.39% (8 out of 46) of T. gondii patients diagnosed with ELISA were actually positive for the parasite, using RT-PCR technology, 82.61% (38 out of 46) had a negative RT-PCR result. The distribution of cases diagnosed with RT PCR among KLT cancers was 50% in breast cancer patients, and at equal rates of 12.50% in bowel and lung cancer and leukocyte cancer, followed by prostate cancer patients respectively.

Keywords: Toxoplasma gondii; PCR; Cancer; Kirkuk; IgG. ,


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