Abstract:Turkeys are known to be natural hosts for the zoonotic protozoan parasite Toxoplasma gondii. The objective of the present study was to gain further knowledge of possible predilection sites of T. gondii infection in this species after parenteral application of tachyzoites. A total of 38 turkeys were infected with different doses of T. gondii tachyzoites. Birds were killed either 6 to 8 or 10 to 12 weeks after the experimental infection. Fourteen different tissues per bird were investigated by a nested polymeras… Show more
“…A positive control consisting of DNA from cell culture-derived ME49 tachyzoites and a negative control (aliquot of currently used DNA elution buffer) were carried along in every PCR batch. The PCR reaction was performed as a direct PCR followed by a nested PCR as described by Zöller et al (2013). The mastermix for a direct PCR reaction with 25 μ L contained 0·5 U GoTaq ® Flexi Polymerase and 1×GoTaq ® Flexi Buffer (Promega GmbH, Mannheim, Germany), 200 μ m of each dNTP (Fermentas, St. Leon Rot, Germany), 3 m m MgCl 2 , 0·4 μ m of each primer Tg1 (5′-AAA AAT GTG GGA ATG AAA GAG-3′) and Tg2 (5′-ACG AAT CAA CGG AAC TGT AAT-3′).…”
Section: Methodsmentioning
confidence: 99%
“…Fowl is considered to be one of the most important intermediate hosts in the life cycle of T. gondii (Dubey, 2010 b ), but little is known about the duration of persistence of T. gondii in tissue of poultry. Zöller et al (2013) demonstrated a persistence of T. gondii in turkeys over a period of 12 weeks but to our knowledge the persistence of T. gondii in chicken has not been investigated. There is little information as to whether chickens are able to eliminate a T. gondii infection, as has been observed for some of the other intermediate host species (Beverley et al 1977).…”
Toxoplasma gondii is a widely spread protozoon in humans, mammals and poultry. Regarding the latter, nothing is known yet about the duration of T. gondii persistence and distribution over a conventional fattening cycle of turkeys and chickens. Twenty-four turkeys and 12 broiler chickens were infected intravenously with 1×10(6) T. gondii tachyzoites (strain NED). Serum antibody levels were determined weekly by ELISA (turkeys) or immunofluorescent antibody test (chickens). Turkeys were slaughtered at 4, 8, 12 and 16 weeks post-infection (p.i.), and chickens 5 or 10 weeks p.i. (n = 6 per group). Sixteen different tissue samples per bird were analysed for T. gondii by PCR. All infected animals showed seroconversion. In turkeys, 15.9% of all samples were tested positive for T.-gondii-DNA. Among the edible tissues (drumstick, thigh, breast muscle, heart, liver and gizzard) 7.8% tested positive. Among poultry slaughtered after different periods of time after infection no significant differences (P>0.05) regarding the number of positive samples were observed. Only 4 out of 192 samples (2.1%) from infected chickens contained detectable T. gondii DNA.The PCR findings suggested that T. gondii may persist in poultry. Particularly in turkey it was shown that edible tissues stay infected for at least 16 weeks p.i. which indicates a potential risk for consumers of undercooked turkey meat whereas chickens appear less susceptible to T. gondii infection.
“…A positive control consisting of DNA from cell culture-derived ME49 tachyzoites and a negative control (aliquot of currently used DNA elution buffer) were carried along in every PCR batch. The PCR reaction was performed as a direct PCR followed by a nested PCR as described by Zöller et al (2013). The mastermix for a direct PCR reaction with 25 μ L contained 0·5 U GoTaq ® Flexi Polymerase and 1×GoTaq ® Flexi Buffer (Promega GmbH, Mannheim, Germany), 200 μ m of each dNTP (Fermentas, St. Leon Rot, Germany), 3 m m MgCl 2 , 0·4 μ m of each primer Tg1 (5′-AAA AAT GTG GGA ATG AAA GAG-3′) and Tg2 (5′-ACG AAT CAA CGG AAC TGT AAT-3′).…”
Section: Methodsmentioning
confidence: 99%
“…Fowl is considered to be one of the most important intermediate hosts in the life cycle of T. gondii (Dubey, 2010 b ), but little is known about the duration of persistence of T. gondii in tissue of poultry. Zöller et al (2013) demonstrated a persistence of T. gondii in turkeys over a period of 12 weeks but to our knowledge the persistence of T. gondii in chicken has not been investigated. There is little information as to whether chickens are able to eliminate a T. gondii infection, as has been observed for some of the other intermediate host species (Beverley et al 1977).…”
Toxoplasma gondii is a widely spread protozoon in humans, mammals and poultry. Regarding the latter, nothing is known yet about the duration of T. gondii persistence and distribution over a conventional fattening cycle of turkeys and chickens. Twenty-four turkeys and 12 broiler chickens were infected intravenously with 1×10(6) T. gondii tachyzoites (strain NED). Serum antibody levels were determined weekly by ELISA (turkeys) or immunofluorescent antibody test (chickens). Turkeys were slaughtered at 4, 8, 12 and 16 weeks post-infection (p.i.), and chickens 5 or 10 weeks p.i. (n = 6 per group). Sixteen different tissue samples per bird were analysed for T. gondii by PCR. All infected animals showed seroconversion. In turkeys, 15.9% of all samples were tested positive for T.-gondii-DNA. Among the edible tissues (drumstick, thigh, breast muscle, heart, liver and gizzard) 7.8% tested positive. Among poultry slaughtered after different periods of time after infection no significant differences (P>0.05) regarding the number of positive samples were observed. Only 4 out of 192 samples (2.1%) from infected chickens contained detectable T. gondii DNA.The PCR findings suggested that T. gondii may persist in poultry. Particularly in turkey it was shown that edible tissues stay infected for at least 16 weeks p.i. which indicates a potential risk for consumers of undercooked turkey meat whereas chickens appear less susceptible to T. gondii infection.
“…Indeed, T . gondii infection is prevalent in many domestic and wild avian species, although the epidemiological role of those species is poorly understood [ 1 , 5 , 7 , 8 , 9 ]. Birds are suspected to act as dispersive agents of T .…”
Understanding the spread of Toxoplasma gondii (T. gondii) in wild birds, particularly in those with opportunistic feeding behavior, is of interest for elucidating the epidemiological involvement of these birds in the maintenance and dissemination of the parasite. Overall, from 2009 to 2011, we collected sera from 525 seagull chicks (Yellow-legged gull (Larus michahellis) and Audouin’s gull (L. audouinii)) from 6 breeding colonies in Spain and tested them using the modified agglutination test (MAT) for the presence of antibodies against T. gondii. Chick age was estimated from bill length. Main food source of seagull chicks was evaluated using stable isotope analyses from growing scapular feathers. Overall T. gondii seroprevalence was 21.0% (IC95% 17.5–24.4). A generalized linear mixed-effects model indicated that year (2009) and food source (freshwater) were risk factors associated to the individual risk of infection by T. gondii, while age (days) was close to significance. Freshwater food origin was related to the highest seroprevalence levels, followed by marine origin, supporting freshwater and sewages as important routes of dispersion of T. gondii. Year differences could indicate fluctuating rates of exposure of seagull chicks to T. gondii. Age ranged from 4 to 30 days and seropositivity tended to increase with age (P = 0.07), supporting that seropositivity is related to T. gondii infection rather than to maternal transfer of antibodies, which in gulls is known to sharply decrease with chick age. This study is the first to report T. gondii antibodies in Yellow-legged and Audouin’s gulls, thereby extending the range of intermediate hosts for this parasite and underscoring the complexity of its epidemiology.
“…A study on pigs sacrificed at 76 dpi19 showed 3/6 positive liver samples. Zöller et al showed, on 30 turkeys sacrificed 6–12 weeks after intravenous injection of tachyzoïtes,20 that liver and breast muscle were the most infected organs, with Toxoplasma DNA detection in 43.3% and 26.7% of samples, respectively.…”
AimToxoplasmosis following liver transplant with donor–recipient mismatch is rare, but is often life-threatening. However, there are no data on the frequency of cyst carriage in the liver, nor consensual chemoprophylaxis guidelines. This study aimed at describing frequency and localisation of Toxoplasma cysts in the liver in a mouse model of chronic infection to predict the risk in liver transplantation.MethodsHeart, brain and liver lobes of 21 mice chronically infected with Toxoplasma were collected for DNA extraction and amplification of Toxoplasma gondii rep529 sequence by real-time PCR.ResultsParasite DNA was detected in the liver of 19/21 mice (90.5%), with no preferential anatomical localisation, but with higher parasite loads in the papillary process. Parasite loads in the liver were far lower than in brain and heart. The number of infected lobes was inversely correlated to the total liver weight, but was independent of the brain parasite load and of the parasite strain.ConclusionsThe liver is a frequent site of cyst carriage, confirming that transplantation of an organ from a seropositive donor to seronegative recipient is at high risk for acquired toxoplasmosis. Systematic serological screening prior to transplantation and chemoprophylaxis in patients at risk are fully justified.
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