Résumé
In April 1998 urine samples from adult female buffaloes were collected in a farm located in Registro, Vale do Ribeira, São Paulo State, Brazil. The urine samples obtained after furosemide injection were immediately transported to the laboratory in liquid modified EMJH medium and seeded, by the serial dilution technique, into Fletcher's or modified EMJH-0.2 (per cent) agar, both of them with 5-fluorouracil 100mg/mL. The intraperitoneoum inoculation of 0.5 mL was also performed with each urine sample in young, adult hamsters (Mesocricetus auratus). All samples seeded directly in culture medium were contaminated. The hamsters did not show any sign of disease and were killed at the 21st post inoculation day. At this time kidney cultures of these animals were performed and from one of them, one leptospira strain (M04-98) was isolated, identified as belonging to serogroup Sejroe by Microscopic Agglutination Test (MAT) with a panel of 36 rabbit sera against serovars representative for the pathogenic serogroups. Subsequently, MAT was carried out with antisera against the 19 reference strains of serogroup Sejroe, revealing a close relationship with serovar guaricura. Afterwards the MAT was done with a panel of 18 monoclonal antibodies representative for serovars of serogroup Sejroe. The histogram closely resembled that of serovar guaricura. So Cross Agglutination Absorption Test (CAAT) was carried out with the buffalo isolate and guaricura, supporting the relationship between the buffalo isolate and serovar guaricura.