ABSTRACT
Abstract Toxoplasma gondii presents a high prevalence worldwide, infecting several animals. Felines are considered the definitive hosts and among the intermediate hosts we highlight mammals and birds. The man can become infected by ingesting tissue cysts present in birds and mammals. Biological and molecular aspects of T. gondii allows a better understanding of the epidemiology of toxoplasmosis. This work is a serologic screening of 58 chickens grown (Gallus gallus domesticus) for human consumption in Espírito Santo State, by means of indirect haemagglutination assay (IHA). Thirteen chickens tested positive for anti-T. gondii antibodies. The heart and brain of five positive chickens were harvested, treated with pepsin and inoculated separately, in two Swiss mice, intraperitoneally. Tachyzoites were observed in the peritoneum of all the animals, between seven and 10 days after the inoculum. Ten isolates were obtained and biologically characterised in BALB/c mice inoculated with 101 to 104 tachyzoites. All isolates were classified as virulent or intermediately virulent. Isolates were genotyped by means of polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis, revealing three different genotypes. None of the isolates exhibited the clonal type I, II or III genotype. No genotypic differences were observed between the isolates from the brain or heart from the same bird.
Resumo Toxoplasma gondii apresenta alta prevalência mundial, capaz de infectar diversos animais. Felinos são considerados os hospedeiros definitivos e entre os hospedeiros intermediários destacamos os mamíferos e as aves. O homem pode se infectar ingerindo cistos teciduais presentes na carne das aves e mamíferos. O conhecimento dos aspectos biológicos e moleculares do parasito possibilitam melhor entendimento da epidemiologia da toxoplasmose. Neste trabalho foi realizada triagem sorológica por hemaglutinação indireta (HI) em 58 galinhas caipiras (Gallus gallus domesticus) utilizadas para consumo humano, provenientes do estado do Espírito Santo, Brasil. Treze galinhas apresentaram sorologia positiva para T. gondii. O coração e o cérebro de cinco galinhas positivas foram colhidos, tratados com pepsina e inoculados separadamente, em dois camundongos Swiss, por via intraperitoneal. Observou-se taquizoítos no peritônio de todos os camundongos, entre sete e 10 dias após o inóculo. Foram obtidos 10 novos isolados de T. gondii os quais foram estudados em camundongos BALB/C inoculados com 101 a 104 taquizoítos por animal. Todos os isolados foram considerados virulentos ou de virulência intermediária. A caracterização molecular dos isolados, realizada por PCR-RFLP, demonstrou a ocorrência de três genótipos distintos. Nenhum isolado apresentou genótipo clonal ou linhagem clonal do Brasil. Não foi observada diferença molecular (PCR-RFLP) entre os isolados obtidos a partir do cérebro ou do coração da mesma ave. Dois isolados já haviam sido relatados na literatura como causadores de doenças em humanos.
Subject(s)
Female , Mice , Poultry Diseases/parasitology , Toxoplasma/pathogenicity , Antibodies, Protozoan/blood , Chickens/parasitology , Toxoplasmosis, Animal/diagnosis , Poultry Diseases/diagnosis , Toxoplasma/isolation & purification , Toxoplasma/genetics , Polymorphism, Restriction Fragment Length , Brazil , Agglutination Tests , Polymerase Chain Reaction , DNA, Protozoan/analysis , Genotype , Mice, Inbred BALB CABSTRACT
BACKGROUND In southeastern Brazil, autochthonous cases of malaria can be found near Atlantic Forest fragments. Because the transmission cycle has not been completely clarified, the behaviour of the possible vectors in those regions must be observed. A study concerning the entomological aspects and natural infection of anophelines (Diptera: Culicidae) captured in the municipalities of the mountainous region of Espírito Santo state was performed in 2004 and 2005. Similarly, between 2014 and 2015, 12 monthly collections were performed at the same area of the study mentioned above. METHODS Center for Disease Control (CDC) light traps with CO2 were set in open areas, at the edge and inside of the forest (canopy and ground), whereas Shannon traps were set on the edge. FINDINGS A total of 1,414 anophelines were collected from 13 species. Anopheles (Kerteszia) cruzii Dyar and Knab remained the most frequently captured species in the CDC traps set in the forest canopy, as well as being the vector with the highest prevalence of Plasmodium vivax/simium infection, according to molecular polymerase chain reaction techniques. CONCLUSIONS P. vivax/simium was found only in abdomens of the mosquitoes of the subgenus Nyssorhynchus, weakening the hypothesis that this subgenus also plays a role in malaria transmission in this specific region.