Domestic swine in a visceral leishmaniasis endemic area produce antibodies against multiple Leishmania infantum antigens but apparently resist to L. infantum infection.
In order to investigate whether pigs can be infected by Leishmania infantum, a serological and parasitological study was carried out on swine in the Jequié municipality, Northeast of Brazil. Anti-Leishmania infantum antibodies were detected in 37 out of 92 swine (40.2%), by two different assays: an anti-L. infantum lysate and an anti-K39 recombinant protein ELISA. An experimental study was also carried out to verify the susceptibility of domestic pigs to L. infantum infection. Three sows inoculated with 10(8) stationary-phase infective L. infantum promastigotes (26% metacyclic promastigotes) per kilogram of body weight produced anti-Leishmania antibodies until the end of the experiment, 11 months later. No parasites, however, could be visualized through optical microscopy of spleen, liver and bone marrow or by in vitro culture of these organs. Homogenates of these organs were also inoculated in hamsters, without producing infection. No Leishmania DNA was detected by polymerase chain reaction (PCR) in sand flies fed on these animals. The results indicate that domestic pigs bitten by L. infantum-infected vectors in the endemic area do not display a full infection pattern, and the positive association in endemic areas between the presence of swine and infection in canines may not be ascribable to the former acting as a parasite reservoir.
Moraes-Silva
Evandro
E
Centro de Pesquisas Gonçalo Moniz (CPqGM), Fundação Oswaldo Cruz, Rua Waldemar Falcão 121, Brotas, CEP: 40295-001, Salvador, Bahia, Brazil.
Antunes
Fabiana Rodrigues
FR
Rodrigues
Marcio Silva
MS
da Silva Julião
Fred
F
Dias-Lima
Artur Gomes
AG
Lemos-de-Sousa
Valderez
V
de Alcantara
Adriano Costa
AC
Reis
Eliana Almeida Gomes
EA
Nakatani
Maria
M
Badaró
Roberto
R
Reis
Mitermayer Galvão
MG
Pontes-de-Carvalho
Lain
L
Franke
Carlos Roberto
CR
D000818:Animals; D000913:Antibodies, Protozoan / Q000096:biosynthesis* / Q000097:blood; D000953:Antigens, Protozoan / Q000737:chemistry; D015153:Blotting, Western / Q000662:veterinary; D001938:Brazil / Q000453:epidemiology; D006224:Cricetinae; D016054:DNA, Protozoan / Q000235:genetics; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D005260:Female; D018314:Leishmania infantum / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification*; D007898:Leishmaniasis, Visceral / Q000175:diagnosis* / Q000453:epidemiology / Q000276:immunology / Q000469:parasitology; D016133:Polymerase Chain Reaction / Q000662:veterinary; D015800:Protozoan Proteins / Q000737:chemistry; D016036:Seroepidemiologic Studies; D013552:Swine; D013553:Swine Diseases / Q000453:epidemiology / Q000276:immunology / Q000469:parasitology*
D000913:Antibodies, Protozoan; D000953:Antigens, Protozoan; D016054:DNA, Protozoan; D015800:Protozoan Proteins; C079253:K39 antigen, Leishmania