The aims of this study were to investigate the frequency of pulmonary hemorrhage (PH) in mice unable to produce functional B and T lymphocytes and to explore the effect of an inducible nitric oxide synthase gene (Inos) knockout (KO) on the frequency/severity of interstitial nephritis in vivo. We studied the outcome of infection by the virulent Leptospira interrogans serovar Copenhageni strain Cop. The animals used were Inos KO mice, recombination activating gene 1 (Rag1) KO mice, CB17 severe combined immunodeficiency (SCID) mice, and the respective wild-type (WT) C57BL/6 and BALB/c controls. The Inos KO and WT mice survived with no clinical symptoms of leptospirosis. The frequency and severity of nephritis was significantly lower in the Inos KO mice. All of the Rag1 KO and SCID animals died of acute leptospirosis, whereas all of the WT mice survived. PH was observed in 57 and 94% of Rag1 KO mice and in 83 and 100% of SCID mice, using inoculum doses of 10 7 and 10 6 leptospires, respectively. There was no evidence of PH in the WT controls. In conclusion, the loss of the Inos gene had a negligible effect on the outcome of leptospiral infection, although we observed a reduced susceptibility for interstitial nephritis in this group. Of note, the absence of functional B-and T-cell lymphocytes did not preclude the occurrence of PH. These data provide evidence that PH in leptospirosis may not be related only to autoimmune mechanisms.

Few studies have compared the seroprevalence of antileptospiral agglutinins with the demonstration of urinary shedding of leptospires or evidence of active infection in the bloodstreams of non-human primates. The study population consists of 58 animals, including d 42 monkeys from the Zoological Park of Salvador (Parque Zoobotânico Getúlio Vargas), Bahia, Brazil. The study also evaluated 16 primates (Cebus sp.) rescued from illegal trade that were housed in the Wildlife Rehabilitation Center of Salvador (CETAS), Bahia, Brazil. The seroprevalence of antileptospiral antibodies was low (2%) in the animals from the Zoo. A higher rate (31%) was observed among the animals that were rescued from illegal trade in the state of Bahia. Even if all the blood and urine samples were negative for leptospiral DNA fragments, the high frequency of serological evidence of exposure suggests a potential risk of leptospirosis transmission when keeping these animals as pets.INDEX TERMS: Leptospirosis, Leptospira, Primates.rEsUMO.-[Indícios de exposição a leptospiras em primatas neotropicais resgatados do comércio ilegal e de um Zoológico da Bahia.] Poucos estudos compararam a soroprevalência de aglutininas antileptospira com a demonstração de excreção urinária de leptospiras ou evidên-cia de infecção ativa em primatas não humanos. A população estudada consistiu em 58 animais, sendo 42 primatas do Parque Zoobotânico Getúlio Vargas, Bahia, Brasil. O estudo avaliou ainda 16 primatas (Cebus sp.) resgatados do tráfico ilegal e abrigados no Centro de Triagem de Animais Silvestres Chico Mendes, Salvador, Bahia, Brasil. A soroprevalên-cia de anticorpos antileptospira foi baixa (2%) nos animais do Zoológico. Uma taxa mais elevada (31%) foi observada nos animais resgatados do tráfico ilegal. Mesmo que todas as amostras de sangue e urina tenham sido negativas para DNA de leptospiras, a alta frequência de evidência de exposição nos animais de origem selvagem indicam o risco potencial da adoção de primatas como animais de estimação.