Serotyping of Toxoplasma gondii in cats (Felis domesticus) reveals predominance of type II infections in Germany.
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.


METHODS
To establish a peptide-microarray serotyping test, we identified 24 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).


RESULTS
Positive cat reference sera reacted predominantly with peptides harbouring amino acid sequences specific for the clonal T. gondii type the cats were infected with. When the array was applied to field sera from Germany, 98.8% (85/86) 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 presenting amino-acid sequences 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.
Institute of Epidemiology, Friedrich-Loeffler-Institut, Federal Research Institute for Animal Health, Greifswald - Insel Riems, Germany.
Pavlo
P
Maksimov
Johannes
J
Zerweck
Jitender P
JP
Dubey
Nikola
N
Pantchev
Caroline F
CF
Frey
Aline
A
Maksimov
Ulf
U
Reimer
Mike
M
Schutkowski
Morteza
M
Hosseininejad
Mario
M
Ziller
Franz J
FJ
Conraths
Gereon
G
Schares
D000818:Animals; D000913:Antibodies, Protozoan / Q000096:biosynthesis / Q000097:blood*; D000953:Antigens, Protozoan / Q000097:blood*; D002371:Cat Diseases / Q000097:blood / Q000453:epidemiology / Q000276:immunology* / Q000469:parasitology; D002415:Cats; D005260:Female; D005858:Germany / Q000453:epidemiology; D056724:Immunity, Humoral; D007118:Immunoassay; D008297:Male; D010455:Peptides / Q000138:chemical synthesis / Q000276:immunology; D040081:Protein Array Analysis; D012703:Serotyping; D014122:Toxoplasma / Q000145:classification / Q000276:immunology*; D014124:Toxoplasmosis, Animal / Q000097:blood / Q000453:epidemiology / Q000276:immunology* / Q000469:parasitology
D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D010455:Peptides