Epidemiology Study of Trichinella Spiralis Infection in Tyumen Region.

Trichinosis is a parasitic infection with worldwide distribution, which is caused by consuming pork or other meats containing cystic larvae of the parasitic nematode Trichinella Spiralis. This study aimed to investigate the status of infection Trichinella Spiralis in domestic and wild animals. To study the spread of trichinelles in animals, a retrospective analysis was conducted based on the study of research journals and conducted their research methods of compressor trichinelloscopy (microscopic) and digestion of samples in artificial gastric juice (biochemical). A total of 17 positive samples were detected for trichinellosis during the observation period, of which 58.8% belonged to a badger (Meles Meles), and 35.3% to the brown bear (Ursusarctos), and only 5.9% of wild boar (Susscrofa). The mean long-term extent of infection belonged to badgers (18.2%), bears (7.9%), and wild boars (0.05%). The study found that between 2015 and 2020, seventeen Trichinella cases were recorded among wildlife in the Tyumen region and the Khanty-Mansi Autonomous Region. The number of annual Trichinella detection cases was declining, indicating the effectiveness of veterinary services. This study determined that the primary source of infection was bears, badgers, and wild boars. Among the 17 positive samples, 58.8% belonged to the badger, 35.3% to the bear, and only 5.9% to the wild boar.

Immunomodulatory in vitro effects of Trichinella cystatin-like protein on mouse splenocytes.

Trichinella parasites have developed specific mechanisms allowing successful completion of their life cycle. These mechanisms are in a great part involved in immunomodulation and studying them may provide a valuable insight into the functioning of the immune system. Trichinella products may be also used as potential therapeutic agents to treat immune diseases. This study investigates the immunomodulatory potential of recombinant multi cystatin-like protein (CLP) derived from T. britovi to determine whether CLP has anti-inflammatory properties in vitro. CLP is a highly antigenic glycoprotein present in Trichinella excetory-secretory (ES) products. AlphaFold structure prediction confirms that it consists of three type-two cystatin-like domains. Mouse splenocytes were stimulated in vitro with lipopolysaccharide (LPS) and co-stimulated with recombinant CLP. The culture supernatants were collected and tested for secreted cytokine levels using ELISA. CLP was found to reduce LPS-induced secretion of inflammatory cytokines TNFα and IL-6. On the contrary, in some experimental groups, co-stimulation with CLP resulted in increased secretion of the regulatory cytokine IL-10. The obtained results indicate that CLP has anti-inflammatory properties and future research on its function is advisable, specifically in the context of the therapy of inflammatory disorders.

The "starry night" (diffuse microcalcific myopathy) - thousands of muscle microcalcifications after 30 years of Trichinella infection detected by ultrasound.

Trichinellosis, a parasitosis transmitted through consumption of raw or undercooked meat from pigs and game animals, is responsible for a specific myositis. The calcifications of infected myocytes and larva can be detected during many years postin-fection. We present the case of a male patient with a history of severe trichinellosis with disease onset 30 years ago, presenting with generalized muscle microcalcifications detected during musculoskeletal ultrasound evaluation. The ultrasound aspect of the muscles was indeed spectacular; hence, the comparison with a "starry night".

Expression of Trichinella spiralis serpin Tsp_01570 in Pichia pastoris: a first insight of its biomodulatory activity.

Serpins represent one of the most diverse families of serine protease inhibitors. Despite their complexity, they are virtually found in all organisms and play an important role in homeostasis processes such as blood coagulation, inflammation, fibrinolysis, immune responses, chromatin condensation, tumor suppression, and apoptosis. There has recently been particular interest in studying serpin functions in infection and inflammation, especially since more serpins from parasites have been identified and characterized. Among helminths, Trichinella spiralis is one of the few parasites with an extremely strong ability to induce host immune suppression. Previous studies show that serpins are present in Trichinella and are expressed differentially at different parasite stages. More interesting, there is evidence of a recombinant serpin from Trichinella pseudospiralis that alters macrophage polarization in vitro. This finding could be relevant to comprehend the modulation process of the immune response. We expressed Tsp_01570, a putative serpin gene from Trichinella spiralis, in the eukaryotic system Pichia pastoris SMD1168H and evaluated its presence at different parasite stages, finding the serine protease inhibitor in the crude extract of adult worms. The effect of recombinant serpin on THP-1 cells was tested by quantification of IL-12p40, TNF-α, IL-4, and IL-10 cytokines released by ELISA. We also evaluated the expression of the M1 markers, CCR7 and CD86, and the M2 markers, CD163 and CD206, by immunofluorescence staining. This study represents the first insight in elucidating the importance of serpin Tsp_01570 as a potential molecular modulator.

Trichinella Infection Ameliorated Vincristine-Induced Neuroinflammation in Mice.

Vincristine (VCR) is a chemotherapeutic agent widely used in treatment of malignancies. However, VCR has a limitation in use since it commonly causes a painful neuropathy (VCR-induced peripheral neuropathy, VIPN). Inflammatory cytokines secreted by immune cells such as macrophages can exacerbate allodynia and hyperalgesia, because inhibiting the inflammatory response is a treatment target for VIPN. In this study, we investigated whether Trichinella spiralis, a widely studied helminth for its immunomodulatory abilities, can alleviate VCR-induced allodynia. Von Frey test showed that T. spiralis infection improved mechanical allodynia at 10 days after VCR injection. We further observed whether the difference was due to mitigated axon degeneration, but no significant difference between the groups in axonal degeneration in sciatic nerves and intra-epidermal nerve fibers was found. Conversely, we observed that number of infiltrated macrophages was decreased in the sciatic nerves of the T. spiralis infected mice. Moreover, treatment of T. spiralis excretory-secretory products caused peritoneal macrophages to secrete decreased level of IL-1ß. This study suggests that T. spiralis can relieve VCR-induced mechanical allodynia by suppressing neuroinflammation and that application of controllable degree of helminth may prove beneficial for VIPN treatment.

Identification and profiling of Trichinella spiralis circulating antigens and proteins in sera of mice with trichinellosis.

Trichinellosis is a zoonotic disease caused by the ingestion of the Trichinella nematode. With a worldwide incidence of approximately 10,000 cases per year, Trichinella spiralis is responsible for most human infections. There are no specific signs or symptoms of this parasitic infection. Muscle biopsy is the gold diagnostic standard for trichinellosis, but the technique is invasive and unable to detect the early stage of infection. Although immunodiagnostics are also available, antibody detection usually occurs after 3 weeks and prolonged up to 19 years after the acute phase. Therefore, additional diagnostic biomarkers must be identified to improve trichinellosis diagnosis. This study aimed to measure concentration changes in mouse serum proteins prior to T. spiralis infection and 2, 4 and 8 weeks after infection, and to identify T. spiralis circulating proteins and antigens using mass spectrometry-based proteomics. Mouse muscle-related proteins including inter-alpha-trypsin inhibitor heavy chain H2, a protein involved in the response to muscle tissue damage, were up-regulated in mouse sera during the T. spiralis larvae invasion. Additionally, 33 circulatory parasite proteins were identified in infected mouse sera. Notably, T. spiralis long-chain fatty acid transport protein 1 could be detected in the early stage of infection and peroxidasin-like protein was identified 2, 4 and 8 weeks after infection. Seventeen T. spiralis circulating antigens were detected in mouse immune complexes, with PX domain protein being found 2, 4 and 8 weeks after infection. Because peroxidasin-like protein and PX domain protein were detected at all post-infection time points, sequence alignments of these proteins were performed, which showed they are conserved among Trichinella spp. and have less similarity to the human and murine sequences. Integrative analysis of T. spiralis biomarkers throughout the course of infection may reveal additional diagnostic targets to improve early diagnosis of trichinellosis.

Trichinosis Imitating an Inflammatory Systematic Disease.

Trichinellosis (trichinosis) is a parasitic infection caused by nematodes of the genus Trichinella. Pigs are the most common source of human infection. We describe a case of a 47-year-old woman presented with a wide range of intermittent symptoms including prolonged fever, dry cough, diarrhea, rash, myalgias and arthralgias. The patient was attended by physicians with various medical specialties such as dermatologists, rheumatologists and allergiologists, but they did not establish a certain diagnosis because of the gradual onset of symptoms, raising the suspicion of a systematic disease. After extensive work up, the diagnosis of trichinosis was established with femoral muscle biopsy compatible with inflammatory myopathy of parasitic etiology with trichinosis to be the predominant diagnosis. Despite the significant delay of diagnosis for almost three months, patient was treated successfully with no further complications. Trichinellosis is a food-borne treatable infection. Preventive measures include community education especially in zones where parasite prevalence is increased, improvement of farming and cooking techniques.

Reprint of: Gamma radiation effect on Trichinella pseudospiralis and Trichinella spiralis infected wild boar meat.

Trichinellosis is a foodborne parasitic disease caused by Trichinella spp. Different methods, such as cooking, freezing and irradiation, have been suggested to inactivate the parasite in meat infected with Trichinella spp. The International Commission on Trichinellosis (ICT) recommends an irradiation dose of 0.3 kGy to inactivate Trichinella spp. larvae, but its effectiveness in all Trichinella species has not yet been demonstrated. Therefore, the objective of the present study was to determine the effectiveness of gamma radiation in treating wild boar meat to inactivate Trichinella pseudospiralis and Trichinella spiralis. Two wild boars (Sus scrofa) were each inoculated per os (PO) with 20,000 muscle larvae (ML) of Trichinella. One wild boar was inoculated with T. pseudospiralis and the other one with T. spiralis. Both wild boars were euthanized 20 weeks post infection (pi). A 250░g sample from each selected muscle type (side ribs, shoulder and upper forelegs) was obtained in duplicate from each animal. One group of samples was not irradiated (Gc; n░=░6) while the other group of samples was irradiated (Gt; n░=░6) at the Atomic Centre of the Argentinean National Commission of Atomic Energy (CNEA) with a minimum and maximum dose of 0.32-0.41 kGy. Twenty gram of each muscle from Gt and Gc were taken at 24░h, 7 days, 14 days and 21 days post-irradiation, and all samples were individually processed by means of artificial digestion. The ML were then inoculated into mice to evaluate the intestinal phase and the muscular phase. All recovered larvae from Gt and Gc samples showed integrity of the cuticle and active motility. Adult worms and ML were recovered from all mice inoculated with ML from Gc. However, no adult worms or ML were obtained in mice inoculated with ML from Gt. These results show the efficacy of irradiation to inhibit the development of T. pseudospiralis and T. spiralis in the host, which could possibly be extended to other non-encapsulated species, but further studies are needed to demonstrate this hypothesis.

Reprint of: The European badger, Meles Meles, as a new host for Trichinella britovi in Romania.

The European badger, Meles meles (Carnivora, Mustelidae) is a widespread opportunistic omnivorous mammal. Its food spectrum comprises a wide variety of plants and small animals, occasionally including rodents, such as mice or rats. Considering that rodents are known to play a key role in the life cycle of Trichinella spp., the aims of this study were to investigate the occurrence of these parasites in badgers from Romania and to identify the species. Overall, 61 badgers originating from 14 counties were examined by trichinoscopy and artificial digestion. For species determination, the positive muscle samples, and the larvae recovered from the artificial digestion were used for DNA isolation, and further processed by multiplex PCR. A single badger, originating from Sibiu County, Central Romania, was found positive for Trichinella spp. Five cysts were identified using trichinoscopy: four in the diaphragm and one in the foreleg muscles. Artificial digestion revealed an infection rate of 70 larvae/100 g of muscle. The PCR indicated the occurrence of T. britovi, which is the most commonly detected species in wild carnivores in temperate areas. Although T. britovi has previously been reported in Romania, this represents the first report of its occurrence in the European badger in the country. However, the low prevalence indicates a minor reservoir role of this species.

Reprint of: Survival of Trichinella spiralis in cured meat products.

Processing of meat is one possible approach to control meat-borne parasites. Processing methods such as freezing, cooking and irradiation are recommended for the control of Trichinella in pork, horse or game meat if specific technical conditions are fulfilled. Curing is a widely used preservation process influencing product characteristics such as shelf life, food safety, and taste. As curing methods are characterized by high parameter variability and predictions about inactivation of parasitic stages in raw meat products are difficult, curing and smoking are not recommended for Trichinella control. The objective of this study was to investigate the survival of T. spiralis in cured raw sausages taking into account water activity (aw-value), pH value, temperature, and time. For this purpose, four different types of sausage (Knackwurst, vacuum packed Knackwurst, short ripened salami, long ripened salami) were produced using T. spiralis infested batter. After production, the sausages were stored at product specific conditions for up to 35 days. During storage, pH value and aw-value of the sausages were monitored over time. Further, sausages of each type were digested using the magnetic stirrer method and the viability of the isolated larvae was assessed using a previously published larval motility test as a proxy for viability and infectivity of Trichinella larvae. In this context, we also introduce a three-level rated infectivity score (RIS) with a clear categorization scheme allowing the assessment of the infectivity of larvae. Based on the RIS, larvae isolated from the salamis were regarded as potentially infective until day 2 (short ripened salami) or day 3 (long ripened salami) post ripening, whereas in Knackwurst, potentially infective larvae were still found by day 8 post ripening. In contrast potentially infective larvae were detected in vacuum-packed Knackwurst until day 24 post ripening. Finally, using the RIS approach, data from previously published studies were collected and subjected to a correlation analysis to identify matrix factors linked to short Trichinella inactivation times.

Evaluation of a cystatin-like protein of Trichinella spiralis for serodiagnosis and identification of immunodominant epitopes using monoclonal antibodies.

An antigenic cystatin-like protein (Ts-CLP) selected from cDNA library of intestinal infective larvae at 6 h post-infection, was expressed by prokaryotes in the form of a histidine-tagged protein (rTs-CLP). The fusion protein was purified by an on-column refolding procedure using Ni-NTA affinity chromatography. An indirect rTs-CLP ELISA was developed using 270 known negative serum samples from commercial swine maintained under non-special pathogen free conditions. Based on the distribution of the signal-to-positive (S/P) ratio, a cut-off value was set at 0.30. Using this cut-off value, rTs-CLP ELISA was evaluated using sera from swine experimentally infected with 1000 and 50,000 muscle larvae of Trichinella spiralis. Specific IgG antibodies were detectable by rTs-CLP ELISA as soon as 17 days post-infection (dpi), but the commercial ELISA kit based on excretory-secretory (ES) antigens did not permit detection before 21 dpi. Three monoclonal antibodies (McAbs) against Ts-CLP (designated 1H9, 6B5 and 7F8) were obtained by screening with both rTs-CLP ELISA and ES ELISA methods. Two dominant epitopes recognized by McAbs were determined by analysis with overlapping fusion peptides and synthetic peptides. One epitope 39 HEALFSSDLKQESGV 53 was recognized by 1H9 and 6B5, and the other epitope 178 REALFSSDSKEQSGV 192 was recognized by 7F8. The generation of McAbs against Ts-CLP and the characterization of the two dominant epitopes provide a foundation for the development of a specific early serodiagnostic strategy for T. spiralis infection.

Myocarditis and Raw Meat Consumption: Strange Bedfellows!

Trichinellosis is a parasitic infection that is associated with the consumption of raw meat. The specific genotype Trichinella nativa has been found in raw bear meat. The most common genotype that has been linked with myocarditis is T spiralis. We present a case of T nativa myocarditis secondary to consumption of raw bear meat. The clinical manifestations as well as therapy of this specific genotype is outlined.

Trichinella spiralis in a cougar (Puma concolor) hunted by poachers in Chile / Trichinella spiralis em um puma (Puma concolor) caçado por caçadores furtivos no Chile

Abstract Trichinellosis is a zoonosis caused by nematodes of the Trichinella genus, of which 10 species have been described. Species identification when larvae is found is only possible using molecular tools. Meat from pigs and game animals not subjected to veterinary inspection are the main sources of human infections. The hunting of native carnivores is prohibited in Chile due to conservation issues and the fact that those animals favor pest control. The illegal hunting of a cougar (Puma concolor) occurred in September 2020. Herein, the molecular identification of Trichinella larvae, by analyzing nuclear (expansion segment V) and mitochondrial (cytochrome C oxidase subunit I) sequences are described. Both the amplification of the expansion segment V region and the phylogenetic analysis of a segment of a fragment of the cytochrome c-oxidase subunit I sequence confirmed that the larvae belonged to T. spiralis. The case described herein represents the first evidence of illegal hunting of a protected mammal infected with Trichinella in Chile, highlighting the 'One Health' perspective to face this disease in the rural-sylvatic interphase.

Resumo A triquinelose é uma doença causada por nematoides do gênero Trichinella. Dez espécies foram descritas. A identificação das espécies a partir das larvas só foi possível com ferramentas moleculares. O abate doméstico de suínos e o consumo de animais de caça, sem inspeção veterinária, são as principais fontes de infecção humana. A caça de carnívoros nativos é proibida no Chile por questões de conservação e pelo fato de que esses animais favorecem o controle de pragas. A caça ilegal de um puma (Puma concolor) aconteceu em setembro de 2020. No Chile, a identificação molecular de larvas de Trichinella, obtida pelo exame de sequências nucleares (segmento de expansão V) e mitocondriais (citocromo C oxidase subunidade I) são descritas. Tanto a amplificação da região do segmento de expansão V quanto a análise filogenética de um segmento de um fragmento da sequência da subunidade I da Citocromo c-oxidase, confirmaram que as larvas pertenciam a T. spiralis. O caso aqui descrito representa a primeira evidência de caça ilegal de um mamífero protegido infectado com Trichinella no Chile, destacando a perspectiva de "Saúde Única" para enfrentar esta doença na interfase rural-silvestre.

Statistical approach to Trichinella infection in horses handled by rural slaughterhouses across five distinctive socioeconomic regions in Mexico

Abstract This work aimed to investigate the prevalence of Trichinella infection in horses (Equus ferus caballus) handled by rural slaughterhouses across five distinctive socioeconomic regions in Mexico. Serum samples were obtained by non-probabilistic convenience sampling in the Eastern, Southern Central and Western regions (100 samples of each). Additionally, muscle tissue samples were collected from the East (n = 45), Southeastern (n = 88), Southern Central (n = 39) and Southwestern (n = 11) regions. Antibodies were determined by Western blot and the muscle tissue was examined by artificial digestion. A global antibody prevalence of 2% was obtained. Regionally, a prevalence of 5% was observed in the East and 1% in the Southern Central region. No antibodies were detected in the West region and no larvae were found in the muscle tissue samples. These findings support the low presence of Trichinella in Mexican horses, which can positively impact the Mexican horse meat trade.

Resumen Se investigó la prevalencia de Trichinella en caballos (Equus ferus caballus) demataderos rurales en cinco regiones socioeconómicas de México. Los sueros se obtuvieron por Trichinella muestreo de conveniencia no probabilístico en las regiones Este, Centrosur y Oeste (100 muestras de cada una). Además se colectaron muestras de tejido muscular de animales de las regionesEste (n = 45), Centro Sur (n = 39), Sudeste (n = 88) y Sudoeste (n = 11). Los anticuerpos se determinaron por Western blot y el tejido muscular se examinó por digestión artificial. Se obtuvo una prevalencia global de anticuerpos del 2%. A nivel regional se observó una prevalencia del 5% enel Este y del 1% en el Centrosur. No se detectaron anticuerpos en el Oeste y no se encontraron larvas en el tejido muscular. Los datos respaldan la baja presencia de Trichinella en caballos mexicanos, lo que puede impactar positivamente en su comercio.

The European badger, Meles meles, as a new host for Trichinella britovi in Romania.

The European badger, Meles meles (Carnivora, Mustelidae) is a widespread opportunistic omnivorous mammal. Its food spectrum comprises a wide variety of plants and small animals, occasionally including rodents, such as mice or rats. Considering that rodents are known to play a key role in the life cycle of Trichinella spp., the aims of this study were to investigate the occurrence of these parasites in badgers from Romania and to identify the species. Overall, 61 badgers originating from 14 counties were examined by trichinoscopy and artificial digestion. For species determination, the positive muscle samples, and the larvae recovered from the artificial digestion were used for DNA isolation, and further processed by multiplex PCR. A single badger, originating from Sibiu County, Central Romania, was found positive for Trichinella spp. Five cysts were identified using trichinoscopy: four in the diaphragm and one in the foreleg muscles. Artificial digestion revealed an infection rate of 70 larvae/100 g of muscle. The PCR indicated the occurrence of T. britovi, which is the most commonly detected species in wild carnivores in temperate areas. Although T. britovi has previously been reported in Romania, this represents the first report of its occurrence in the European badger in the country. However, the low prevalence indicates a minor reservoir role of this species.

Differences in larval survival and IgG response patterns in long-lasting infections by Trichinella spiralis, Trichinella britovi and Trichinella pseudospiralis in pigs.

BACKGROUND: Domesticated and wild swine play an important role as reservoir hosts of Trichinella spp. and a source of infection for humans. Little is known about the survival of Trichinella larvae in muscles and the duration of anti-Trichinella antibodies in pigs with long-lasting infections. METHODS: Sixty pigs were divided into three groups of 20 animals and infected with 10,000 larvae of Trichinella spiralis, Trichinella britovi or Trichinella pseudospiralis. Four pigs from each group were sacrificed at 2, 6, 12, 18 and 24 months post-infection (p.i.) and the number of larvae per gram (LPG) of muscles was calculated. Serum samples were tested by ELISA and western blot using excretory/secretory (ES) and crude antigens. RESULTS: Trichinella spiralis showed the highest infectivity and immunogenicity in pigs and larvae survived in pig muscles for up to 2 years p.i. In these pigs, the IgG level significantly increased at 30 days p.i. and reached a peak at about 60 days p.i., remaining stable until the end of the experiment. In T. britovi-infected pigs, LPG was about 70 times lower than for T. spiralis at 2 months p.i. and only very few infecting larvae were detected at 6 months p.i., whereas no larvae were detected at 12, 18 and 24 months p.i. At 6 months p.i., degenerated/calcified larvae and cysts were detected in the muscles by trichinoscopy and histology. The IgG pattern showed by T. britovi-infected pigs was similar to that of T. spiralis-infected pigs, although seroconversion occurred some days later. The larval burden of T. pseudospiralis was slightly greater than for T. britovi at 2 months p.i., but no larvae were detected at 6 and 12 months p.i. In T. pseudospiralis-infected pigs, seroconversion occurred slowly, as in T. britovi-infected pigs. The IgG level showed a significant drop at 6 months p.i. and declining to the cut-off value at 12 months p.i. CONCLUSIONS: The longer survival of T. spiralis in pigs in comparison with the other two species highlights its exceptional dissemination potential. These results provide an explanation of the controversial data collected by parasitological and serological tools in the course of epidemiological investigations.

Human Outbreak of Trichinellosis Caused by Trichinella papuae Nematodes, Central Kampong Thom Province, Cambodia.

In September 2017, a severe trichinellosis outbreak occurred in Cambodia after persons consumed raw wild pig meat; 33 persons were infected and 8 died. We collected and analyzed the medical records for 25 patients. Clinical signs and symptoms included myalgia, facial or peripheral edema, asthenia, and fever. We observed increased levels of creatine phosphokinase and aspartate aminotransferase-, as well as eosinophilia. Histopathologic examination of muscle biopsy specimens showed nonencapsulated Trichinella larvae. A Trichinella excretory/secretory antigen ELISA identified Trichinella IgM and IgG. Biopsy samples were digested and larvae were isolated and counted. PCR for the 5S rDNA intergenic spacer region and a multiplex PCR, followed by sequencing identified the parasite as Trichinella papuae. This species was identified in Papua New Guinea during 1999 and in several outbreaks in humans in Thailand. Thus, we identified T. papuae nematodes in humans in Cambodia.

Trichinella spiralis y Trichinella patagoniensis: estudio de la carga globular aplicando el método de Azul Alcian / Trichinella spiralis and Trichinella patagoniensis: study of globular charge applying Alcian Blue method / Trichinella spiralis e Trichinella patagoniensis: estudo da carga globular pelo método de Azul de Alcian

Resumen Los residuos de ácido siálico de las glicoproteínas de superficie son los principales responsables de la carga negativa eritrocitaria. El objetivo de este trabajo fue estudiar alteraciones de carga globular producidas por Trichinella spiralis y Trichinella patagoniensis. Se trabajó con concentrados de larvas musculares de ambas especies y con eritrocitos frescos. Se incubó el sedimento globular con igual volumen de concentrado larval (1 y 2 horas). Los controles fueron incubados con solución salina. Se aplicó el método de Azul Alcian y se determinó el coeficiente experimental de carga aniónica eritrocitaria (CexpCAE). Los resultados mostraron que la carga disminuyó con el aumento del tiempo de tratamiento para ambas especies. Los valores de CexpCAE de las suspensiones incubadas con T. spiralis fueron menores que con T. patagoniensis, indicando que T. spiralis produjo mayor disminución de carga que T. patagoniensis. Se concluye que la desialización producida por ambas especies no es la misma, lo que sugiere que la relación hospedador-parásito que se establecería in vivo sería distinta.

Abstract The sialic acid residues of the surface glycoproteins are mainly responsible for the erythrocyte negative charge. The objective of this work was to study alterations of globular charge produced by Trichinella spiralis and Trichinella patagoniensis. Work was carried out on muscle larvae concentrates of both species and fresh erythrocytes. The treatment was performed by incubating the globular pellet with equal volume of larval concentrate (1 and 2 hours). Controls were incubated with saline solution. The Alcian Blue method was applied and the experimental coefficient of erythrocyte anion charge (expCEAC) was determined. The results showed that the globular charge decreased with increasing treatment time for both species. The expCEAC values of the suspensions incubated with T. spiralis were lower than with T. patagoniensis, indicating that T. spiralis produced a greater decrease in charge than T. patagoniensis. It is concluded that the desialization produced by both species is not the same, suggesting that the host-parasite relationship that would be established in vivo would be different.

Resumo Os resíduos de ácido siálico das glicoproteínas de superfície são os principais responsáveis pela carga negativa dos eritrócitos. O objetivo desse trabalho foi estudar as alterações da carga globular produzidas por Trichinella spiralis e Trichinella patagoniensis. Trabalhamos com concentrados de larvas musculares de ambas as espécies e com eritrócitos frescos. O tratamento foi realizado incubando o sedimento globular com igual volume de concentrado larval (1 e 2 horas), Os controles foram incubados com solução salina. Foi aplicado o método de Azul de Alcian e se determinou o coeficiente experimental de carga aniônica de eritrócitos (CexpCAE). Os resultados mostraram que a carga diminuiu com o aumento do tempo de tratamento para ambas as espécies. Os valores de CexpCAE das suspensões incubadas com T. spiralis foram menores que com T. patagoniensis, indicando que T. spiralis produziu uma diminuição maior na carga que T. patagoniensis. Conclui-se que a dessalinização produzida por ambas as espécies não é a mesma, sugerindo que a relação hospedeiro parasita que seria estabelecida in vivo é diferente.

Trichinella spiralis y Trichinella patagoniensis: cinética de desialización eritrocitaria / Trichinella spiralis and Trichinella patagoniensis: kinetics of erythrocyte desialization / Trichinella spiralis e Trichinella patagoniensis: cinética de dessialização eritrocitária

El objetivo del trabajo fue estudiar la cinética de desialización eritrocitaria producida por larvas infectantes de Trichinella spiralis y Trichinella patagoniensis. Se trabajó con 7 suspensiones eritrocitarias incubadas con 1.000±200 larvas musculares/mL, durante 2 horas, tomando muestra al tiempo inicial y cada 15 minutos. Los respectivos eritrocitos controles se incubaron de la misma manera con solución salina. Se aplicaron el método de titulación por Polibrene calculando el CexpST y un análisis de varianza (ANOVA) con las comparaciones múltiples según Tukey. Los resultados mostraron que el valor promedio de CexpST disminuyó con el aumento del tiempo de incubación, para ambas especies. En el tratamiento con T. spiralis no hubo diferencias significativas entre el valor medio del coeficiente a tiempo 60 y 75 minutos, mientras que con T. patagoniensis, a 45 y 60 minutos. Todas las restantes diferencias fueron significativas. La comparación entre los tratamientos, para cada uno de los tiempos, mostró que al tiempo inicial el coeficiente promedio no difirió entre las especies, pero que a todos los otros tiempos fue significativamente menor en la incubación de los eritrocitos con T. spiralis. Se concluye que la relación hospedador-parásito que se establece en ambos casos es distinta y probablemente también la capacidad de adaptación y de daño al hombre.

The objective of this work was to study the kinetics of erythrocyte desialization produced by infective larvae of Trichinella spiralis and Trichinella patagoniensis. It was performed on 7 erythrocyte suspensions incubated with 1,000±200 muscle larvae/ mL for 120 minutes, taking samples at the initial time and every 15 minutes. The respective control erythrocytes were incubated in the same way with saline solution. The Polybrene Titration method calculating the CexpST and variance analysis (ANOVA) with the multiple comparisons according to Tukey were applied. The results showed that the average value of CexpST decreased with the increase in incubation time, for both species. There were no significant differences between the mean value of the coefficient at 60 and 75 minutes in the treatment with T. spiralis, while neither were there any differences between 45 and 60 minutes in the incubation with T. patagoniensis. All other differences were significant. The comparison between the two treatments, for each of the times, showed that at the initial time the average coefficient did not differ between the species, but at all other times it was significantly lower in the incubation of the erythrocytes with T. spiralis. It is concluded that the parasite host relationship that is established in both cases is different and probably also is the ability to adapt and cause harm to man.

O objetivo do trabalho foi estudar a cinética de dessialização eritrocitária. produzida por larvas infectantes de Trichinella spiralis e Trichinella patagoniensis. O trabalho foi feito com 7 suspensões eritrocitárias incubadas com 1.000±200 larvas musculares/mL por 2 horas, colhendo amostras no tempo inicial e a cada 15 minutos. Os respectivos eritrócitos-controle foram incubados da mesma forma com solução salina. Foi aplicado o método de titulação por Polibreno calculando o CexpST e também uma análise da variância (ANOVA) com as comparações múltiplas de acordo com Tukey. Os resultados mostraram que o valor médio de CexpST diminuiu com o aumento do tempo de incubação para ambas as espécies. No tratamento com T. spiralis não houve diferenças significativas entre o valor médio do coeficiente no tempo 60 e 75 minutos, ao passo que com T. patagoniensis, aos 45 e 60 minutos. Todas as diferenças restantes foram significativas. A comparação entre os tratamentos, para cada um dos tempos, mostrou que no tempo inicial o coeficiente médio não diferiu entre as espécies, mas que em todos os outros tempos foi significativamente menor na incubação dos eritrócitos com T. spiralis. A conclusão é que a relação hospedeiro-parasita, estabelecida em ambos os casos, é diferente e provavelmente também a capacidade de adaptação e dano ao homem.

The Immunological Properties of Recombinant Multi-Cystatin-Like Domain Protein From Trichinella Britovi Produced in Yeast.

Trichinellosis is a globally-distributed zoonotic parasitic disease caused by nematode worms of the genus Trichinella. One of the most common species of Trichinella known to affect human health is T. britovi; however, it is relatively poorly investigated. A thorough knowledge of the proteins expressed by Trichinella is important when developing immunological detection methods and vaccines and studying its interactions with the host. The present study uses the Pichia pastoris expression system to produce a soluble TbCLP antigen which induces strong antibody responses in the host during natural infection. Our results demonstrate the feasibility of TbCLP antigen production in yeasts, which are able to carry out post-translational modifications such as glycosylation and disulfide bond formation; they also indicate that the glycosylated TbCLP antigen had immunogenic effects in the tested mice and induced a mixed Th1/Th2 response, and was associated with a reduced larval burden after challenge with T. britovi. Subsequent in vitro stimulation of mice splenocytes revealed that TbCLP most likely possesses immunomodulatory properties and may play a significant role in the early phase of infection, affecting host immunological responses.