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Background. Trichinellosis is a parasitic zoonosis transmitted to humans by consumption of raw or undercooked meat from animals infected by worms of the Trichinella genus. Every year seropositive cases are found among the human population and thus trichinellosis still remains an epidemiologically important disease in Poland. The usefulness of ELISA for anti-T. spiralis IgG detection in pigs is still limited by the nature of antigen. The objective in the present study was to compare the usefulness of excretory-secretory antigens of L1 T. spiralis for the serological detection of IgG antibodies in pigs. Material and methods. The antigens were prepared in different laboratories: Ag ES L1 T. spiralis (N) in Germany, Ag ES L1 T. spiralis (W) in Italy and Ag ES L1 T. spiralis in Poland. Conventional, Iberian pigs were infected with 200, 1000 and 20 000 muscle larvae of T. spiralis. Serum samples were obtained at 5 and 1 dbi (day before infection), and 5, 10, 15, 20, 25, 30, 40, 50, 60 dpi (day post infection) and screened for specific IgG antibodies to excretory-secretory L1 T. spiralis antigens. Serum samples were obtained from the EU project TRICHIPORSE. The cut-off value of ELISA was determined on serum samples from 248 Trichinella-free pigs from Poznań and Boża Wola, that were examined by artificial digestion. Results. In pigs infected with 200 L1 T. spiralis larvae, specific IgG were detectable from 50 dpi, when the Ag ES L1 T. spiralis (N) was used, whereas when Ag ES L1T. spiralis (W) and Ag ES L1 T. spiralis were used, the specific IgG were detectable from 40 dpi. In pigs infected with 1000 L1 T. spiralis larvae, specific IgG was observed from 30 dpi when Ag ES L1 T. spiralis (W) and Ag ES L1 T. spiralis were used, but when Ag ES L1 T. spiralis (N) was used specific IgG were detectable from 40 dpi. In the group infected with the highest dose of T. spiralis larvae, specific IgG were detectable from 30 dpi when Ag ES L1 T. spiralis (N) and Ag ES L1 T. spiralis (W) were used, whereas when Ag ES L1 T. spiralis was used specific IgG were detectable from 20 dpi. The results strongly indicated that in the examined pigs, the specific IgG response against T. spiralis infection is dose dependent. Furthermore, it was shown that the high infectious dose induced earlier increasing of specific IgG response. Statistical analysis revealed a significant positive correlation between OD values obtained in procedures based on the three antigens. The results were statistically repeatable for procedures and for single pigs (P<0.01).
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ELISA can be used to measure produced antibodies or Trichinella spp. antigens in the samples. They are detected with antibodies linked to an enzyme that reacts with a substrate and generate a colour reaction. The optical density (OD) of the reaction is measured spectrophotometrically. ELISA assays can be done in several different procedures called „direct”, "indirect", "sandwich", and "competition" ELISA. Since the 1970s, the studies have been done on improving or replacing direct methods of Trichinella diagnosis with serological methods based on the ELISA. When somatic antigens of L1 T. spiralis were used, the specificity of the ELISA was poor due to a high probability of cross-reactions with other pathogens. During the 1980s the specificity of the ELISA was improved by excretory-secretory (E/S) antigens obtained during Trichinella muscle larvae incubation in vitro. Recently a synthetic glycan antigen has been developed and the increasing of ELISA specificity and sensitivity was noticed. The sensitivity of the ELISA using an E/S antigen ranging from 93.1 to 99.2% but the specificity from 90.6 to 99.4%. The ELISA method is relatively simple to apply, reliable, readily standardized and provides an acceptable balance of sensitivity and specificity. But all modified procedures should be validated. In Poland, the studies on the usefulness of ELISA for antibodies detection against T. spiralis in pigs and wild animals are limited. Own ELISA procedure was prepared in Pathophysiology Lab. in W. Stefański Institute of Parasitology of PAS. ELISA was used to examine IgG level against L1 T. spiralis in pigs and wild boars serum samples. Of 1474 pig samples, only 12 were positive. Of 1880 wild boar samples only 14 were positive. The results of this study are comparable with performance obtained using commercial sets. The results showed the usefulness of ELISA for T. spiralis diagnosis in pigs and wild boars and confirmed the possibility of use the ELISA test for application in the slaughterhouse.
In the European Union a considerable proportion of massive quantities of sewage sludge produced in municipal sewage treatment plants are used in agriculture, landfilled, incinerated or composted. In Poland the main form of disposal is landfilling. The authors review sewage sludge management presented in the National Urban Sewage Sludge Program and in the National Waste Management Plan.
The aim of the study carried out on ten young (10-week old) pigs of the native Polish Large White breed experimentally infected with a low dose of 300 invasive muscle larvae (ML) of Trichinella spiralis was intravital detection of trichinellosis using the E-S ELISA test, determination of a variation level of IgG antibodies against excretory-secretory (E-S) antigens of T. spiralis muscle larvae and finally, describing the intensity of T. spiralis larvae infection in selected muscles. The pig sera were collected at 7 and 9 days prior to the experimental infection with T. spiralis and at 9, 14, 20, 23, 25, 27, 30, 33, 37, 41, 46 days post-infection (d.p.i.). The anti-T. spiralis IgG antibodies were detected by a commercial E-S ELISA test (PrioCHECK Trichinella Ab). Average intensity of the T. spiralis infection in the examined muscles of pigs ranged from 1.52 up to 43.09 larvae/g. The studies revealed that the E-S antigen in the ELISA test did not show cross-reaction with the sera of pigs infected with Oesophagostomum spp. The ELISA assay did not recognize trichinellosis in pigs until 27 days after the T. spiralis infection. The anti-T. spiralis IgG antibodies were first detected on day 30 post-infection. A statistically significant increase of IgG antibodies against T. spiralis ML E-S antigens was first observed between days 27-30 (p<0.01) post-infection, and a further significant rise in the antibody level occurred between days 27 and 33 (p<0.01); 30 and 33 (p<0.01); 33 and 37 (p<0.05) following infection.
Mierzono stężenie platyny w powietrzu nad ulicami Częstochowy i Katowic w 1996 r. Platynę wyłapywano, przepompowując powietrze przez filtry poliwęglanowe o średnicy porów 0,8 µm i oznaczano metodą spektrometrii absorpcyjno-atomowej. W 50 próbkach stwierdzono średnie stężenie platyny 6,69 (SD 1,14) pg/m3.
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