Molecular Identification of Toxoplasma gondii in the Native Slaughtered Cattle of Tehran Province, Iran

Toxoplasmosis, caused by Toxoplasma gondii, is a common parasitic disease, affecting almost one-third of the world’s population. It is transmitted by ingestion of food or water contaminated with oocysts excreted by cats and the consumption of raw or undercooked meat from ruminants. This study aimed at molecular characterization of T. gondii in native cattle from West of Tehran, Iran.

A total of 180 samples were collected from the cattle diaphragms (n=80) and heart muscles (n=100) from multiple slaughterhouses. The nested Polymerase Chain Reaction (PCR) assay was carried out to amplify the GRA6 gene of T. gondii. The PCR-Restriction Fragment Length Polymerase (PCR-RFLP) assay was also performed on positive samples, using Tru1I (MseI) restriction enzyme. Data were statistically analyzed using SPSS (v.15.0).

T. gondii was found in 38 out of 180 (21.1%) samples. The infection rate in heart muscle samples (16.66%) was significantly (p<0.05) higher than the diaphragm samples (4.44%). The PCR-RFLP pattern by MseI enzyme showed that 13 (7.22%) samples were genotype II, while 25 (13.88%) were genotype III, having statistically meaningful difference (p<0.05). No genotype I was found in the studied isolates.

Based on our findings, the frequency of T. gondii was high in the study area. Therefore, educational programs need to be implemented in order to inform people about the risks of raw or undercooked meat consumption.