Toxoplasma gondii infection in slaughtered pigs and cattle in Poland: seroprevalence, molecular detection and characterization of parasites in meat

Abstract

Background Toxoplasma gondii infection may pose a severe medical problem especially in a congenital form and as an acquired infection in immunocompromised persons. Raw and undercooked meat of slaughtered animals is regarded as an important source of parasite infection; however, data concerning this issue in Poland are still insufficient. The aim of this study was to estimate the prevalence of T. gondii infection in pigs and cattle slaughtered for human consumption in Poland using serological and molecular methods. Methods Sera of 3111 pigs and 2411 cattle from 16 regions (voivodeships) of the country were examined for the presence of anti-T. gondii IgG using the direct agglutination test (DAT). Pepsin-digested samples of diaphragm and heart of seropositive animals were examined for the presence of T. gondii DNA (B1 gene) by nested PCR and real-time PCR, while non-digested samples were only examined by nested PCR. The B1 gene DNA samples were genotyped at 11 genetic markers using multilocus nested PCR-RFLP (Mn-PCR-RFLP) and sequencing. Results Seropositive DAT results were found in 11.9% of pigs and 13.0% of cattle. The highest seroprevalence was found in pigs from Podkarpackie (32.6%) and in cattle from Mazowieckie (44.6%). Data analysis showed that cattle > 5–10 years-old, as well as cattle and pigs from small farms, and pigs from farms with open production systems, had higher odds of testing seropositive (P < 0.05). Among the examined tissue samples, positive PCR results were found in samples from 12.2% and 10.2% of seropositive pigs and cattle, respectively. Among the samples successfully genotyped by Mn-PCR-RFLP and sequenced, four samples were identified as T. gondii type II and one sample as type I. Conclusions The presence of T. gondii antibodies in a substantial proportion of examined pigs and cattle as well as the detection of parasite DNA in their tissues highlight a potential health risk to the consumers in Poland.

Proteomic and Bioinformatic Investigations of Heat-Treated Anisakis simplex Third-Stage Larvae

“…Unfortunately, foodborne parasites remain neglected compared with bacterial and viral pathogens [3]. Therefore, studies in this field, like epidemiological surveys [5,6], development of novel diagnostic tools [7][8][9], drug discovery [10], or investigation of pathogenicity [11], are particularly valuable.…”

A serological survey of Toxoplasma gondii in Polish pigs from organic farms, other housing systems and in pigs of different age groups

“…Experimentally-infected sows have been found to produce IgG class antibodies within two to three weeks of infection, and these antibodies remained for at least 38 weeks [ 52 ]. In pigs, the presence of anti- T. gondii antibodies correlates with the presence of parasite tissue cysts in the muscle tissue [ 11 , 12 , 28 , 30 ]; this has been confirmed by comparing seroprevalence with a bioassay confirming or excluding the presence of infective tissue cysts [ 36 ]. Elsewhere, Hill et al [ 53 ] found ELISA analysis of pig serum samples to demonstrate a 100% match with cat bioassay results; they also found MAT (Modified Agglutination Test) on the serum samples to demonstrate 80.64% match and ELISA on meat juice samples to demonstrate a 76.9% match.…”

“…Among these species, pigs (pork) are considered to be one of the main sources of meat-borne infection [ 27 ]. As it is not possible to detect T. gondii tissue cysts during routine post-mortem examination [ 28 ], the EFSA recommends the use of serological tests to detect specific antibodies when testing pigs [ 29 ], as this can indicate presence of tissue cysts in muscles [ 12 , 28 , 30 ].…”

Occurrence of <i>Toxoplasma gondii</i> infection among free-living small rodents and insectivores in the Lublin Province – the role of these animals in epidemiology of toxoplasmosis

“…wyniki badań prowadzonych na fermach świń w Holandii, które wykazały, że drobne gryzonie przypadkowo zjadane przez świnie znacznie przyczyniają się do rozpowszechnienia zarażenia tym pasożytem na fermie [2]. W Polsce odsetek świń zarażonych T. gondii ocenia się na ok. 11% [4]. Wyniki badań oparte na analizie ryzyka wskazują na surowe mięso i surowe produkty mięsne jako najczęstsze źródła inwazji T. gondii ludzi w Europie [5].…”