OBJECTIVES: For the proper diagnosis of toxoplasmosis it is essential to determine the stage of the infection, for which the most preferred method is IgG avidity test. The avidity index (AI) should initially be low (AI≤0.3) in the acute phase and increase during the infection. However, persistent low avidity can occur in patients with latent toxoplasmosis, which can complicate the interpretation of the results. The aim of the study is to explain the causes of this phenomenon. METHODOLOGY: A retrospective study was carried out with 717 serum samples collected from 442 patients from the categories of pregnant and non-pregnant women, men, and newborns + infants (age < 0.5 year). The trends of AI kinetics were evaluated in repeatedly examined patients. The frequency of cases with low avidity was compared in individual categories of patients and in groups of people with acute and non-acute toxoplasmosis. RESULTS: The proportion of patients with initially low avidity was 42.1% in the acute toxoplasmosis group while it was 13.0% in the non-acute groups. In uninfected newborns with anti-Toxoplasma antibodies transmitted from the mother, a decrease in IgG avidity levels over time was observed, resulting in 29.2% of samples showing low (improper) avidity. While the dynamics of IgG avidity and the frequency of cases of improperly low avidity were similar in men and pregnant and non-pregnant women, the category of newborns and infants differed substantially for these indicators. CONCLUSIONS: Due to acceptable specificity and negative predictive value, high avidity can rule out acute toxoplasmosis, but moderate sensitivity complicates the possibility of its confirmation. The results of the avidity test must be interpreted in the context of the results of other methods.

• MeSH
• afinita protilátek MeSH
• ELISA metody   MeSH
• imunoglobulin G * MeSH
• imunoglobulin M MeSH
• kojenec MeSH
• lidé MeSH
• novorozenec MeSH
• protilátky protozoální MeSH
• retrospektivní studie MeSH
• toxoplazmóza * MeSH
• Check Tag
• kojenec MeSH
• lidé MeSH
• mužské pohlaví MeSH
• novorozenec MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Congenital toxoplasmosis is reportable disease in Europe. To prevent it antibody serological tests were introduced in several European countries as a part of screening programmes. Immunoglobulin G (IgG) avidity index testing is one of these tests for diagnosing acute infection with Toxoplasma gondii (Nicolle et Manceaux, 1908) in pregnant women. However, a low or moderate IgG avidity index can give inconclusive results for predicting woman's status. From June 2012 until the end of 2014, 17,990 women were included in the national screening program to prevent congenital toxoplasmosis. One hundred and twenty-six women were consecutively included in the study because they had low or moderate IgG avidity. Every woman with possible acute toxoplasmosis was followed up every month till delivery. Fifty-eight of 126 (46%) women got infected in months before current pregnancy, 39 women (31%) were infected early in pregnancy. Twenty-nine pregnant women of 126 (23%) got infected in the second/third trimester of pregnancy. New cut off for IgG avidity index was 0.11. With this cut off, we were able to exclude T. gondii acute infection in the first trimester with very good diagnostic accuracy (area under the curve (AUC) = 0.95, 95% confidence Interval (CI) 0.91-0.99, sensitivity 0.95, specificity 0.86). If an IgG avidity index above 0.11 is measured in a woman's serum and she is in the first trimester of pregnancy, then a odds ratio (OR) for acute infection with T. gondii is below 1 (OR 0.11, 95% CI 0.05-0.25, P < 0.0001). If we measure IgG avidity index that is ≥ 0.11 in the first trimester of pregnancy, we can exclude infection with T. gondii with good diagnostic accuracy in our cohort of women. With a new cut off we could reduce number of invasive procedures such as amniocentesis and put less pregnant women in distress.

• MeSH
• afinita protilátek MeSH
• imunoglobulin G MeSH
• kongenitální toxoplazmóza * diagnóza   MeSH
• lidé MeSH
• protilátky protozoální MeSH
• první trimestr těhotenství MeSH
• těhotenství MeSH
• Toxoplasma * MeSH
• toxoplazmóza * diagnóza   MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• těhotenství MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

Recombination of antibody genes in B cells can involve distant genomic loci and contribute a foreign antigen-binding element to form hybrid antibodies with broad reactivity for Plasmodium falciparum. So far, antibodies containing the extracellular domain of the LAIR1 and LILRB1 receptors represent unique examples of cross-chromosomal antibody diversification. Here, we devise a technique to profile non-VDJ elements from distant genes in antibody transcripts. Independent of the preexposure of donors to malaria parasites, non-VDJ inserts were detected in 80% of individuals at frequencies of 1 in 104 to 105 B cells. We detected insertions in heavy, but not in light chain or T cell receptor transcripts. We classify the insertions into four types depending on the insert origin and destination: 1) mitochondrial and 2) nuclear DNA inserts integrated at VDJ junctions; 3) inserts originating from telomere proximal genes; and 4) fragile sites incorporated between J-to-constant junctions. The latter class of inserts was exclusively found in memory and in in vitro activated B cells, while all other classes were already detected in naïve B cells. More than 10% of inserts preserved the reading frame, including transcripts with signs of antigen-driven affinity maturation. Collectively, our study unravels a mechanism of antibody diversification that is layered on the classical V(D)J and switch recombination.

• MeSH
• B-lymfocyty * imunologie   MeSH
• CD antigeny imunologie   MeSH
• genomika MeSH
• geny pro imunoglobuliny * MeSH
• imunoglobulinový receptor leukocytů B1 imunologie   MeSH
• inzerční mutageneze MeSH
• lehké řetězce imunoglobulinů genetika   MeSH
• lidé MeSH
• Plasmodium falciparum MeSH
• protilátky protozoální genetika   MeSH
• receptory antigenů T-buněk genetika   MeSH
• receptory imunologické imunologie   MeSH
• rozmanitost protilátek * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Toxoplasmosis is a globally spread disease, affecting humans and many animal species, including birds. Antibodies to Toxoplasma gondii were detected in ostriches from South and North America, Africa and Asia. Except for one study from Spain, there is a lack of information about T. gondii seroprevalence in ostriches from Europe. For this reason, the aim of the study was to detect antibodies to T. gondii in farm-reared ostriches from the Czech Republic. Serum samples of 409 ostriches (Struthio camelus), collected at 9 farms were tested by Latex agglutination test. Antibodies to T. gondii were detected in 149 (36%) birds with a statistical difference for individual farms (8%-71%, p = 0.0121), and regions (8%-65%, p = 0.002). Seropositivity did not statistically differ (p > 0.05) in size of farms (50% and 35% on small and large farms, respectively), sex of birds (38% and 35% in males and females, respectively), season and year of collection. Tissue samples (brain, heart, and pectoral muscle) of 105 birds were also tested by PCR to detect T. gondii DNA. The parasite T. gondii was detected in the brain and heart of one seronegative ostrich (1%) from a small farm. Based on our results, we can assume that ostriches may present high risk of toxoplasmosis for humans through consumption of raw or undercooked ostrich meat and even seronegative individuals could harbor T. gondii in their tissues. To our knowledge, this is the first serological detection of T. gondii in ostriches in the Czech Republic, and the first PCR detection in Europe.

• MeSH
• farmy MeSH
• lidé MeSH
• protilátky protozoální krev   MeSH
• protozoální DNA analýza   MeSH
• rizikové faktory MeSH
• Struthioniformes * krev   parazitologie   MeSH
• Toxoplasma * genetika   imunologie   MeSH
• toxoplazmóza zvířat * krev   diagnóza   epidemiologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Česká republika MeSH

Toxoplasma gondii is an obligate intracellular protozoan parasite with domestic or free-living members of family Felidae known as the only definitive hosts of the parasite. The study aimed to evaluate the seroprevalence of toxoplasmosis in selected population groups in Slovakia and to analyse the infection risk factors. Totally 1536 serum samples of voluntary respondents were examined by EIA Toxoplasma IgG (Test-Line Ltd., Clinical Diagnostics, Brno, Czech Republic). IgG antibodies to T. gondii were detected in 322 (21.0%) sera, with the highest seropositivity recorded among farmers (42.5%) and hunters (28.5%). According to age, the highest seropositivity was recorded in 12-18-year-old Roma children (46.2%), what confirms increased risk of infection in this minority that often lives in inadequate hygiene conditions. When only adult participants were taken into account, the highest seroprevalence was observed in the age group of ≥ 70 years. Higher risk of infection (p < 0.05) was connected with cat ownership, living in rural residency and consumption of raw meat and meat processing. The results underline the importance of preventive measures and ongoing need to improve the knowledge on toxoplasmosis in both professionals and public.

• MeSH
• imunoglobulin G krev   MeSH
• lidé MeSH
• protilátky protozoální krev   MeSH
• průřezové studie MeSH
• rizikové faktory MeSH
• séroepidemiologické studie MeSH
• Toxoplasma imunologie   izolace a purifikace   MeSH
• toxoplazmóza diagnóza   epidemiologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Slovenská republika MeSH

BACKGROUND: In endemic areas of zoonotic leishmaniosis caused by L. infantum, early detection of Leishmania infection in dogs is essential to control the dissemination of the parasite to humans. The aim of this study was to evaluate the serological and/or molecular diagnostic performance of minimally and non-invasive samples (conjunctiva cells (CS) and peripheral blood (PB)) for monitoring Leishmania infection/exposure to Phlebotomus perniciosus salivary antigens in dogs at the beginning and the end of sand fly seasonal activity (May and October, respectively) and to assess associated risks factors. METHODS: A total of 208 sheltered dogs from endemic areas of leishmaniosis were screened. Leishmania DNA detection in PB on filter paper and CS was performed by nested-PCR (nPCR), while the detection of anti-Leishmania antibodies was performed using IFAT and ELISA. The exposure to P. perniciosus salivary antigens (SGH, rSP01 and rSP03B + rSP01) was measured by ELISA. RESULTS: Ninety-seven (46.6%) and 116 (55.8%) of the 208 dogs were positive to Leishmania antibodies or DNA by at least one test at the beginning and end of the sand fly season, respectively. IFAT and ELISA presented a substantial agreement in the serodiagnosis of leishmaniosis. Discrepant PB nPCR results were obtained between sampling points. Leishmania DNA was detected in CS of 72 dogs at the end of the phlebotomine season. The presence of antibodies to the parasite measured by ELISA was significantly higher in dogs presenting clinical signs compatible with leishmaniosis at both sampling points. Phlebotomus perniciosus salivary antibodies were detected in 179 (86.1%) and 198 (95.2%) of the screened dogs at the beginning and end of the phlebotomine season, respectively. CONCLUSIONS: The association between ELISA positivity and clinical signs suggests its usefulness to confirm a clinical suspicion. CS nPCR seems to be an effective and non-invasive method for assessing early exposure to the parasite. PB nPCR should not be used as the sole diagnostic tool to monitor Leishmania infection. The correlation between the levels of antibodies to P. perniciosus saliva and Leishmania antibodies suggests the use of a humoral response to sand fly salivary antigens as biomarkers of L. infantum infection.

• MeSH
• antigeny protozoální imunologie   MeSH
• endemické nemoci prevence a kontrola   MeSH
• hmyz - vektory parazitologie   MeSH
• hmyzí proteiny imunologie   MeSH
• imunoglobulin G krev   MeSH
• konjunktiva cytologie   parazitologie   MeSH
• kousnutí a bodnutí hmyzem MeSH
• Leishmania infantum izolace a purifikace   MeSH
• leishmanióza krev   imunologie   veterinární   MeSH
• nemoci psů parazitologie   prevence a kontrola   přenos   MeSH
• Phlebotomus parazitologie   MeSH
• protilátky protozoální krev   MeSH
• protozoální proteiny imunologie   MeSH
• psi MeSH
• rizikové faktory MeSH
• sérologické testy MeSH
• slinné proteiny a peptidy imunologie   MeSH
• zvířata MeSH
• Check Tag
• psi MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Antibody trapping is a recently described strategy for immune evasion observed in the intestinal trematode Echinostoma caproni, which may aid to avoiding the host humoral response, thus facilitating parasite survival in the presence of high levels of local-specific antibodies. Parasite-derived peptidases carry out the degradation of trapped antibodies, being essential for this mechanism. Herein, we show that cathepsin-like cysteine endopeptidases are active in the excretory/secretory products (ESPs) of E. caproni and play an important role in the context of antibody trapping. Cysteine endopeptidase activity was detected in the ESPs of E. caproni adults. The affinity probe DCG-04 distinguished a cysteine peptidase band in ESPs, which was specifically recognized by an anti-cathepsin L heterologous antibody. The same antibody localized this protein in the gut and syncytial tegument of adult worms. Studies with cultured parasites showed that in vivo-bound antibodies are removed from the parasite surface in the absence of peptidase inhibitors, while addition of cathepsin L inhibitor prevented their degradation. These results indicate that cathepsin L-like peptidases are involved in the degradation of surface-trapped antibodies and suggest that cysteine peptidases are not only crucial for tissue-invading trematodes, but they can be equally relevant at the parasite-host interface in gut-dwelling flukes.

• MeSH
• cysteinové endopeptidasy metabolismus   MeSH
• Echinostoma imunologie   metabolismus   MeSH
• echinostomióza imunologie   parazitologie   MeSH
• imunitní únik imunologie   MeSH
• kathepsin L antagonisté a inhibitory   MeSH
• proteolýza MeSH
• protilátky protozoální imunologie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Babesia caballi (Nuttal, 1910) is one of the causative agents of equine piroplasmosis which causes economic losses to horse industry in China. There is an urgent need for rapid detection method for B. caballi infection in Xinjiang Province, China. To prepare monoclonal antibodies (mAbs) against Bc48 gene of B. caballi (Xinjiang local strains) and establish colloidal gold-immunochromatographic (ICT) assay for diagnosis of the disease, recombinant Bc48 was expressed and purified from Escherichia coli. With purified Bc48 as immunogen in mice, three hybridoma cells named 11F4, 1H2 and 7F4 secreting mAbs against Bc48 of B. caballi were obtained, which showed strong reaction with recombinant Bc48 and Bc48 gene transfected cells. Furthermore, colloidal gold labelled ICT assay based on purified Bc48 recombinant antigen and its mAb was developed. The ICT assay showed high sensitivity and specificity and no cross-reaction with Theileria equi (Laveran, 1901). Total of 56 horse serum samples collected from Xinjiang were tested by ICT and compared with the detection by commercial ELISA kit. The results showed that 32 out of 56 serum samples were positive by ICT and 33 were positive by ELISA. ICT assay had high coincidence (98%) to the reference ELISA kit. mAbs and ICT developed in this study could be provided as an efficient diagnosis tool for infection with B. caballi in horse in Xinjiang area.

• MeSH
• Babesia imunologie   MeSH
• babezióza diagnóza   parazitologie   MeSH
• imunoanalýza metody   veterinární   MeSH
• koně MeSH
• monoklonální protilátky krev   MeSH
• myši inbrední BALB C MeSH
• myši MeSH
• nemoci koní diagnóza   parazitologie   MeSH
• protilátky protozoální krev   MeSH
• protozoální proteiny genetika   imunologie   MeSH
• rekombinantní proteiny genetika   imunologie   MeSH
• senzitivita a specificita MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Čína MeSH

There are not any records on the detection of Toxoplasma gondii and Neospora caninum in tissues of wild birds in the African continent. The aim of the study was to investigate the occurrence of DNA from these protozoan parasites in brain tissue samples collected in years 2014-2015 from 110 wild and domestic birds of 15 orders. Birds came mainly from the province of Limpopo (n=103); the other seven birds came from other five provinces of South Africa. Parasite DNAs were detected by PCR in animal brains. While all samples were negative for N. caninum, T. gondii DNA was detected in three (2.7%) birds: a Red-eyed Dove (Streptopelia semitorquata), a Laughing Dove (S. senegalensis) and a Southern-Yellow-billed Hornbill (Tockus leucomelas), all from Limpopo province. Positive samples were selected for genotyping by a 15 microsatellite markers method in a single multiplex PCR assay. Only the sample from the Red-eyed Dove was successfully genotyped and characterized as type II. This is the first detection of T. gondii in tissue of native African wild birds and the first study focusing on N. caninum in birds from South Africa.

• MeSH
• divoká zvířata parazitologie   MeSH
• DNA bakterií MeSH
• nemoci ptáků parazitologie   MeSH
• Neospora genetika   izolace a purifikace   MeSH
• polymerázová řetězová reakce MeSH
• protilátky protozoální MeSH
• protozoální DNA genetika   MeSH
• ptáci parazitologie   MeSH
• séroepidemiologické studie MeSH
• Toxoplasma genetika   izolace a purifikace   MeSH
• toxoplazmóza zvířat parazitologie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Jihoafrická republika MeSH

BACKGROUND: Canine leishmaniosis (CanL) is an important zoonotic parasitic disease, endemic in the Mediterranean basin. In this region, transmission of Leishmania infantum, the etiological agent of CanL, is through the bite of phlebotomine sand flies. Therefore, monitoring host-vector contact represents an important epidemiological tool, and could be used to assess the effectiveness of vector-control programmes in endemic areas. Previous studies have shown that canine antibodies against the saliva of phlebotomine sand flies are specific markers of exposure to Leishmania vectors. However, this method needs to be further validated in natural heterogeneous dog populations living in CanL endemic areas. METHODS: In this study, 176 dogs living in 12 different locations of an L. infantum endemic area in north-east Spain were followed for 14 months. Blood samples were taken at 5 pre-determined time points (February, August and October 2016; January and April 2017) to assess the canine humoral immune response to whole salivary gland homogenate (SGH) and to the single salivary 43 kDa yellow-related recombinant protein (rSP03B) of Phlebotomus perniciosus, a proven vector of L. infantum naturally present in this region. Simultaneously, in all dogs, L. infantum infection status was assessed by serology. The relationship between anti-SGH and anti-rSP03B antibodies with the sampling month, L. infantum infection and the location was tested by fitting multilevel linear regression models. RESULTS: The dynamics of canine anti-saliva IgG for both SGH and rSP03B followed the expected trends of P. perniciosus activity in the region. Statistically significant associations were detected for both salivary antigens between vector exposure and sampling month or dog seropositivity to L. infantum. The correlation between canine antibodies against SGH and rSP03B was moderate. CONCLUSIONS: Our results confirm the frequent presence of CanL vectors in the study area in Spain and support the applicability of SGH- and rSP03B-based ELISA tests to study canine exposure to P. perniciosus in L. infantum endemic areas.

• MeSH
• endemické nemoci veterinární   MeSH
• hmyz - vektory parazitologie   MeSH
• humorální imunita MeSH
• imunoglobulin G analýza   MeSH
• Leishmania infantum izolace a purifikace   MeSH
• leishmanióza krev   parazitologie   veterinární   MeSH
• longitudinální studie MeSH
• nemoci psů diagnóza   imunologie   parazitologie   MeSH
• Phlebotomus imunologie   MeSH
• protilátky protozoální krev   MeSH
• protilátky krev   MeSH
• psi imunologie   parazitologie   MeSH
• roční období MeSH
• slinné proteiny a peptidy imunologie   MeSH
• slinné žlázy chemie   parazitologie   MeSH
• sliny imunologie   mikrobiologie   parazitologie   MeSH
• zvířata MeSH
• Check Tag
• psi imunologie   parazitologie   MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Španělsko MeSH