Prevalence of Toxoplasma gondii in retail fresh meat products from free-range chickens in Spain

Abstract

Introduction Toxoplasma gondii is one of the most prevalent zoonotic protozoan parasites worldwide and affects the vast majority of warm-blooded animal species, including humans. Postnatal infection in humans occurs through the ingestion of sporulated T. gondii oocysts or via the oral intake of parasite tissue cysts during the consumption of raw or undercooked meat. In this regard, given their high exposure to oocysts, chickens (Gallus domesticus) raised on the ground constitute a potential source of T. gondii. Material and Methods For the first time in Spain, a survey was undertaken in commercial retail free-range poultry. A total of 50 thighs from different animals were analysed. The samples were homogenised and an acid pepsin digestion procedure was applied prior to molecular analysis. Toxoplasma gondii DNA was isolated from meat by qPCR. Two sets of primers were used for DNA amplification targeting the specific sequence of a 529 bp repeat element and another set of primers was utilised for the surface antigen protein-1 gene. Results DNA extracted from 5 out of 50 tissue samples was positive for both genes by qPCR amplification. Conclusion The 10% prevalence of Toxoplasma infection found in commercial free-range chickens raises public health issues.

Toxoplasma gondii in meat of adult sheep in Spain

“…All 216 samples had satisfactory internal control amplifications; positive control amplified correctly in each run. As previously observed ( Gracia et al, 2021 ), the sensitivities of both sets of primers, ToxoRoc and ToxoRepeat, for the 529 bp repeat element were similar. Parasite DNA amplification was observed in 53/216 samples and no amplification was observed in 163/216 samples.…”

“…DNA extraction and the qPCR protocol were performed according to procedures detailed in previous studies ( Gracia et al, 2021 ) with some modifications. Genomic DNA was extracted from a 200 μL volume of the concentrated samples using a commercial Speedtools DNA extraction kit (Biotools B&M Labs S.A, Madrid, Spain).…”

“…Each sample was performed in triplicate and a sample was considered positive if at least two of the triplicates were positive with both pairs of primers. For a result to be considered positive, the threshold cycle ( Ct ) had to be lower than 38, as determined by a standard curve for the set of ToxoRoc primers, according to previously described methods ( Gracia et al, 2021 ).…”

Microbial Risks Caused by Livestock Excrement: Current Research Status and Prospects

“…Reports showed that by using qPCR, Brucella melitensis and Brucella abortus in different samples, including raw milk and cheese, could be determined accurately so as to predict the potential health adversity of the corresponding samples [ 192 , 193 , 194 ]. And zoonotic parasites including Toxoplasma gondii were also determined using qPCR so as to prevent any potential risks that might be caused [ 195 ].…”

Molecular prevalence and genetic diversity of Toxoplasma gondii in free range chicken in Northeastern Libya

“…Food animals are reservoirs of T. gondii and one of the sources of parasite transmission to humans giving T. gondii its medical and veterinary importance ( Tonouhewa et al , 2017 ). Humans get infected by consuming raw or uncooked meat containing tissue cysts, contaminated food or water with oocysts; or, from mother to fetus through vertical transmission in a primary infection ( Hamilton et al , 2019 ; Salinas et al , 2021 ). More than a third of the world’s population has been infected with T. gondii which can have serious consequences for immunodeficient or immunocompromised people ( Mao et al , 2021 ).…”