Altodouro, a new Leptospira serovar of the Pomona serogroup isolated from rodents in northern Portugal.

A Leptospira strain (designated RIM 139) was isolated from the kidney of a house-mouse, Mus musculus, in Trás-os-Montes e Alto Douro region of northern Portugal. The isolate showed typical leptospiral motility and morphology under dark-field microscopy and was pathogenic for hamsters. Species determination was carried out on basis of PCR products generated by species-specific primers and by sequencing of the secY gene. Putative serogroup typing was performed using the microscopic agglutination test (MAT) with a panel of rabbit anti-Leptospira sera representative of the major pathogenic serogroups. Serovar identification was carried out by a combination of monoclonal antibodies and cross-agglutinin absorption test (CAAT). The novel nature of the strain was confirmed by restriction endonuclease analysis (REA). Results showed that RIM 139 represents a new serovar. The name Altodouro is proposed for this new serovar. Speciation findings - PCR analysis of the ompL1 gene and sequencing of the secY gene - indicated that it belonged to Leptospira kirschneri as did amplification with G1/G2 and B64-I/B64-II the primer sets. Crown