Abstract
Background:
Toxoplasma gondii is one of the zoonotic protozoa parasites. It can prevalently infect humans and warm-blooded animals, causing human health problems and substantial economic losses to the livestock industry worldwide. Chicken is one of the potential sources of toxoplasmosis, but there is no report of the prevalence of toxoplasmosis and their genotypes in free-range chickens in Libya.
Aim:
The current study aims to conduct a survey of molecular prevalence and identify the Toxoplasma gondii genotype in free-range chickens and its association with the risk factors of age, gender, and region in Northeastern Libya.
Methods:
This study was conducted by examining a total of 315 free-range chicken organs (brain and heart) derived from three administrative districts in Northeastern Libya. The molecular prevalence was determined by PCR technique using B1 gene amplification and the Toxoplasma gondii genotype was determined by nested PCR-RFLP of GRA6 gene amplicon with restriction enzymes (MseI).
Results:
The overall molecular prevalence of Toxoplasma gondii in free-range chicken in all three districts was 9.5% (30/315), and the highest (15.4%) was in the Al-Marj district (p =0.01; ?2 =9.238). The highest prevalence of Toxoplasma gondii by age was in chickens aged more than two years (p = 0.001; ?2 = 15.530). The difference in Toxoplasma gondii prevalence in male and female chickens was not significant (p = 0.372; ?2 = 0.798). The predominant genotype I (93.3%) had identified at position 544 bp and 194 bp at the GRA6 marker, and only two positives were from genotype II (6.7%) at 700 bp and 100 bp fragment.
Conclusion:
The molecular prevalence of toxoplasmosis in free-range chicken in three districts in Northeastern Libya was 9.5%, and the highest rate was shown in the Al Marj district. Chicken by age more than two years had more risk to transmit toxoplasmosis in human. There was no different infection risk by consuming male or female free-range chicken. It is the first report to determine the predominant genotype, which was genotype I.

Key words: B1 gene, GRA6 gene, Genotyping, Free-range chicken, Toxoplasma gondii.