Molecular prevalence of Toxoplasma gondii in raw meat products sold in Poland. Assessment of the viability of detected parasites

Abstract

Raw and undercooked meat products and meat containing To x-oplasma gondii tissue cysts are considered the main source of human toxoplasmosis in Europe, however data on this subject in Poland are still insufficient. The aim of the study was to de-termine the prevalence of DNA and live T. gondii parasite in raw meat products commecially available in Poland.Samples of various types of raw cured bacon, sausage, ham and minced meat (1900 samples) were collected in shops and meat factories (in cooperation with the Veterinary Inspection) in 16 provinces of Poland (2019-2023). Samples (50 g) were digested with pepsin solution, followed by the DNA extraction. Amplifi-cations of 35-fold-repetitive B1 fragment gene were performed by nested polymerase chain reaction (PCR) and Real-time PCR. Multilocus sequence typing (MLST) with 12 additional genetic markers was used to genotype T. gondii. To assess the viability of T. gondii, isolation assays by cell culture and/or bioassay on mice were performed.Of the 1900 examined samples, 135 (7.1%) tested positive in PCR. The highest percentage of positive results was found for samples from the Łódzkie voivodeship (14.6%) and Pomorskie voivode-ship (12.9), the lowest from the Podlaskie voivodeship (0.7%). The percentage of positive results for particular types of meat products ranged from 1.5% to 9.8%. MLST showed mostly the alleles of clonal type II (47%) and III (31.5%), the combinations of types alleles at different loci were also found (12.7%). The viable T. gondii was isolated from 44 samples.The detection of T. gondii DNA and live parasite in 7.1% and 2.3% of tested samples of raw meat products, respectively, indicates a real threat to consumers’ health.