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

Parasites & Vectors

Giacinto Della Casa¹  Valerio Faeti¹  Maria Angeles Gómez-Morales²  Marco Amati²  Massimo Fabiani²  Simona Cherchi²  Maria Interisano²  Edoardo Pozio²  Alessandra Ludovisi²  Gianluca Marucci²  Daniele Tonanzi²  Elio Licata³  Mattia Ramini⁴  Giuseppe Merialdi⁴  Gianluca Rugna⁴ 

[1] Consiglio per la ricerca in agricoltura e l’analisi dell’economia agraria, Centro di Ricerca Zootecnica e Acquacoltura, Sede di Modena, via Beccastecca 345, 41018, S. Cesario sul Panaro (MO), Italy;Department of Infectious Diseases, Istituto Superiore di Sanità, viale Regina Elena 299, 00161, Rome, Italy;Department of Public Health, Azienda Unità Sanitaria Locale of Modena, Strada Martiniana 21, 4112, Baggiovara, Modena, Italy;Istituto Zooprofilattico Sperimentale of Lombardy and Emilia Romagna, via Pietro Fiorini 5, 40127, Bologna, Italy;

关键词: Trichinella spiralis;    Trichinella britovi;    Trichinella pseudospiralis;    Pig;    Larval burden;    Immune response;    ELISA;    Western blot;    Epidemiology;   

DOI  :  10.1186/s13071-020-04394-7

来源: Springer

【 摘 要 】

BackgroundDomesticated 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.MethodsSixty 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.ResultsTrichinella 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.ConclusionsThe 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.

【 授权许可】

CC BY