Studies were undertaken to determine the efficacy of milbemycin oxime against the enteric adult stages of Trichinella spiralis and of albendazole against the muscle stage larvae in experimentally infected dogs and cats. Specific-pathogen-free Beagle pups (n = 6) and domestic shorthair kittens (n = 6) were inoculated with 7,500 first-stage larvae of Trichinella spiralis. Physical examination (including collection of blood and fecal samples) was performed weekly. During the first week after inoculation, all animals had mild gastrointestinal tract disturbances, but stages of T. spiralis were not observed in the feces. Beginning on postinoculation day (PID) 10, 3 pups and 3 kittens were treated with milbemycin oxime (1.25 mg/kg of body weight, PO, q 12 h) for 10 days. Muscle biopsy specimens were taken from dogs and cats on PID 26 and 29, respectively. Mean numbers of larvae per gram of muscle were 30.3 in the control and 37.7 in the treated dogs. Mean numbers of larvae per gram of muscle in the control and treated cats were 318.7 and 89.3, respectively. Two dogs and 2 cats were removed from the study at that time. The remaining animals, 2 each of the control and milbemycin oxime-treated animals, were given albendazole (50 mg/kg, PO, q 12 h) for 7 days starting at PID 31 and 34 in dogs and cats, respectively. Muscle biopsy specimens were again taken at PID 46 and 49, for dogs and cats, respectively; mean numbers of larvae recovered from muscle were 0.6 for dogs and 13.5 for cats.

Toll-like receptors (TLRs) play an important role in fast activation of the immune response to a variety of pathogens, including parasites. In this study, we focused on TLR2, because this receptor is one of the best known and most frequently analysed members of the TLR family. The aim of this study was to assess the effect of Trichinella spiralis on expression of TLR2 during the intestinal stage of infection. The experimental material consisted of isolates prepared from the intestines (jejunum and colon) of BALB/c mice infected with T. spiralis taken at 4, 8, and 16 days post infection. Our results based on quantitative real-time PCR showed that the mRNA level for TLR2 was statistically significantly higher in the jejuna of mice infected with T. spiralis than in this tissue of uninfected mice. In addition, the presence of TLR2 protein in the intestinal phase of trichinellosis was confirmed by a strong positive immunohistochemical reaction. Our results indicate that infection with T. spiralis changes the expression of TLR2 in the small intestine of the mouse host and suggest a contribution of these receptors to the host defence mechanisms during experimental trichinellosis.

Introduction: Toll-like receptors (TLRs) play a key role in the rapid activation of the innate immune response to a variety of pathogens. The aim of this study was to evaluate the effect of Trichinella spiralis infection on the level of expression of the tlr4 gene in mouse intestines during the intestinal phase of experimental trichinellosis. Material and Methods: The experimental material consisted of the small and large intestines of BALB/c mice infected with Trichinella spiralis sampled at 4, 8, and 16 days post infection (dpi). Results: A statistically significant increase was demonstrated in the tlr4 mRNA level isolated from the infected mice jejunum at 4, 8, and 16 dpi over the uninfected control. Moreover, at 4, 8, and 16 dpi in the jejunum of infected mice, a strong positive reaction for the presence of TLR4 protein compared with that of uninfected mice was observed. Conclusion: Infection with T. spiralis changes the expression of the tlr4 gene in the small intestine of the mouse host.

Experimental and field trials were conducted to evaluate an ELISA for its ability to detect Trichinella-infected domestic swine and to compare ELISA results with muscle-digestion test results. The ELISA used was a commercial double-antibody kit, containing an excretory-secretory antigen, and was evaluated principally for epidemiologic use. Experimentally induced infection in swine (4 groups of 3 pigs each; inoculated with 0, 50, 500 or 5,000 larvae) was detected as early as postinoculation week 4, with seroconversion of all inoculated swine by postinoculation week 8. The rate of seroconversion appeared to be by initial larval dose, time after inoculation, and immunocompetence of the individual host. Determination of antibody kinetics generally revealed rapidly increasing antibody titer, followed by its steady decrease in most pigs. Once seropositive, however, all pigs remained seropositive for the duration of the 10-week study. Presence of muscle larvae was confirmed in all infected pigs at termination of the study. We recognize that the experimental conditions may not be truly representative of those under which natural infection develops in pigs; however, the ELISA detected an infected pig with muscle larval density of 0.87 larvae/g of tissue. Results of a field trial (n = 310) indicated no muscle digestion test-positive pigs (35 g of diaphragm muscle digested/pig), but 3 samples tested positive by ELISA for specificity of 99.0%.

monoclonal antibodies derived from Trichinella spiralis-infected mice reacted with other swine parasites, one monoclonal antibody recognized antigenic determinant specific to T. spiralis, isolation of this antigen by monoclonal antibody-affinity chromatography, use of antigen in enzyme-linked immunosorbent assay eliminated false-positive reactions with serum of healthy swine and detected all pigs infected with T. spiralis

Inoculation of swine with a sylvatic isolate of Trichinella spiralis, designated T s nativa, resulted in low numbers of muscle larvae, compared with muscle larvae accumulation in swine inoculated with a pig type of T s spiralis. Despite low infectivity of T s nativa for swine, primary inoculation resulted in high levels of immunity against challenge infection with T s spiralis. This immunity was expressed in accelerated expulsion of challenge adults from the intestine and reduced numbers of muscle larvae. Pigs inoculated with T s nativa developed cellular and humoral responses similar to those in pigs inoculated with T s spiralis. However, in immunoblots, sera from pigs inoculated with T s nativa recognized additional proteins in muscle larvae excretory-secretory (ES) products, compared with sera from pigs inoculated with T s spiralis. Active immunization of pigs with ES products from T s nativa resulted in numerically higher, but not significantly different levels of immunity, compared with pigs immunized with ES from T s spiralis. The highest levels of immunity were obtained in pigs immunized with a T s spiralis newborn larval extract. The combination of ES products and newborn larval extract did not result in additive levels of immunity. These results indicate that the major immune effector response to Trichinella sp in pigs is against the newborn larvae, regardless of the genetic type of Trichinella sp.

Serum samples obtained from 40,927 swine at various locations in North Carolina between Aug 1, 1987 and July 31, 1988, were tested for antibodies to Trichinella spiralis, using an ELISA based on a larval T spiralis excretory-secretory antigen. In the ELISA, samples were considered to have positive results if the optical density (OD) reading was equal to or 5 times greater than the mean OD value of 4 negative-control sera from trichina-free swine. Of the 40,927 serum samples tested, 154 (0.38%) were positive by ELISA; the rate for breeding swine was 0.35% (105/30,162), and the rate for cull swine was 0.45% (49/10,765). Of the 49 seropositive samples from cull swine, 11 were from out of the state, 22 had no identification, and 16 were known to originate from North Carolina. Seropositivity had a bimodally seasonal distribution, with peaks in March and September. There was no difference between the mean age of seropositive and seronegative swine, but males were at greater risk for seropositivity than were females. Pigs from lots with < 100 sera tested were at increased risk for seropositivity, as were pigs from the central coastal region of North Carolina.

Trichinella spiralis, day-old chicks (exper.), most worms expelled, some matured in intestine and produced larvae which penetrated muscles, little or no development there, followed by death and degeneration, viability of larvae from chickens confirmed by mouse infection

Trichinella spiralis, digestion of infective larvae is important constitutive mechanism of resistance in chickens that probably precludes transmission of infection by gallinaceous birds in nature

This research illustrates the development of a new sliver nanoparticle (Ag-NPs) formulation. Its shape, size, solubility, and stability were characterized using Scanning Electron Microscope (SEM 3D), Transmission Electron Microscope (TEM 2D), Atomic Force Microscope (AFM), and Zeta size and Zeta potential. Exposure of Trichinella spiralis adult worms to 3, 6, 9 and 12 ppm of Ag-NPs each for 3,6,12 and 24 h. In vitro revealed a direct relation between mortalities and the tested drug concentration and exposure time. Anti- T. spiralis effect of Ag-NPs was evaluated by assessing mortality rate and damage in DNA by comet assay and by SEM analysis. Mean mortalities increased from 6.66% after exposure to 3.0 ppm/1 h to 100% after exposure to 12.0 ppm/12 h. The calculated LC50 was 3.0 ppm/10 h, 6 ppm/6 h, 9.0 ppm/4 h and 12.0 ppm/ 3.30 h, while LC100 was 9.0 ppm/24 h and 12.0 ppm/12 h. DNA genotoxic damage of dead worms was directly related to Ag-NPs concentrations for 12h using comet assay as expressed by variations in the percentage of DNA in the tail segment, tail length (μm), tail moment (μm), and olive tail moment. No significant difference (p ≤ .05) between the recorded mortalities and DNA damage between that obtained using the Ag-NPs LC100 and that recorded using Albendazole (50 mg/kg B.W.) for 12 h. SEM images on dead worms revealed clear morphological alteration, multiple vesicles, and blebs, detachment of the epidermis and the sub-epidermal layer with partial sloughing of the cuticle, and loss of normal creases, ridges, and annulations. These morphological alterations were directly related to the concentration of the tested Ag-NPs. The tested new formulation of Ag-NPs appears to be effective in the control of Trichinellosis as an alternative to other resistant drugs.