Serotyping of Toxoplasma gondii in Cats (Felis domesticus) Reveals Predominance of Type II Infections in Germany

Authors: MAKSIMOV, PAVLO - Friedrich-Loeffler-institut; ZERWECK, JOHANNES - Jpt, Peptide Technologies Gmbh; Dubey, Jitender; PANTCHEV, NIKOLA - Idexx Laboratories; FREY, CAROLINE - Institute Of Parasitology - Germany; MAKSIMOV, ALINE - Friedrich-Loeffler-institut; REIMER, ULF - Jpt, Peptide Technologies Gmbh; SCHUTKOWSKI, MIKE - Martin Luther University; HOSSEININEJAD, MORTEZA - University Of Shahrekord; ZILLER, MARIO - Friedrich-Loeffler-institut; CONRATHS, FRANZ - Friedrich-Loeffler-institut; SCHARES, GEREON - Friedrich-Loeffler-institut

Submitted to: PLOS ONE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/1/2013
Publication Date: 11/7/2013
Citation: Maksimov, P., Zerweck, J., Dubey, J.P., Pantchev, N., Frey, C.F., Maksimov, A., Reimer, U., Schutkowski, M., Hosseininejad, M., Ziller, M., Conraths, F.J., Schares, G. 2013. Serotyping of Toxoplasma gondii in Cats (Felis domesticus) Reveals Predominance of Type II Infections in Germany. PLoS One. 8(11):e80213:1- 16. doi:10.1371/journal.pone.0080213.

Interpretive Summary: Toxoplasma gondii is a single-celled parasite of all warm-blooded hosts worldwide. It causes mental retardation and loss of vision in children, and abortion in livestock. Cats are the main reservoir of T. gondii because they are the only hosts that can excrete the resistant stage (oocyst) of the parasite in the feces. Humans become infected by eating under cooked meat from infected animals and food and water contaminated with oocysts. Why some people become sick from toxoplasmosis whereas others remain symptomless is not fully known but the genetic variation among isolates is considered one of the factors. Genetic typing has been based on charactetrization of DNA from the parasite obtsained from infected host and the methods are cumbersome. The authors here describe genotyping based on antibody types in blood reacting to certain protein fractions from the parasite. The results will be of interest to biologists, and Parasitologists.

Technical Abstract: Background: Cats are definitive hosts of Toxoplasma gondii and play an essential role in the epidemiology of this parasite. The study aims at clarifying whether cats are able to develop specific antibodies against different clonal types of T. gondii and to determine by serotyping the T. gondii clonal types prevailing in cats as intermediate hosts in Germany. Methodology: To establish a peptide-microarray serotyping test, we identified 27 suitable peptides using serological T. gondii positive (n=21) and negative cat sera (n=52). To determine the clonal type-specific antibody response of cats in Germany, 86 field sera from T. gondii seropositive naturally infected cats were tested. In addition, we analyzed the antibody response in cats experimentally infected with non-canonical T. gondii types (n=7). Findings: In reference sera of cats infected with one of the three canonical clonal types of T. gondii reactions dominated with peptides harbouring homologous type-specific sequences. When the array was applied to field sera from Germany, 97.7% (84/86) of naturally-infected cats recognized similar peptide patterns as T. gondii type II reference sera and showed the strongest reaction intensities with clonal type II-specific peptides. In addition, naturally infected cats recognized type II-specific peptides significantly more frequently than peptides of other type- specificities. Cats infected with non-canonical types showed the strongest reactivity with peptides specific for both, type I and type III. Conclusions: Cats are able to mount a clonal type-specific antibody response against T. gondii. Serotyping revealed for most seropositive field sera patterns resembling those observed after clonal type II-T. gondii infection. This finding is in accord with our previous results on the occurrence of T. gondii clonal types in oocysts shed by cats in Germany.