Buenos Aires, a new Leptospira serovar of serogroup Djasiman, isolated from an aborted dog fetus in Argentina

This study describes the isolation of a new leptospiral serovar from the Djasiman group from an Argentinean aborted fetus of a dog. The strain was isolated from a culture of mixed liver and kidney tissue from one aborted dog fetus. Bitch's serum showed a titre of 1:800 against the new serovar and 1:400 or less against other serovars tested. Microscopic Agglutination test (MAT) with a panel of 38 rabbit anti-Leptospira sera representative for all pathogenic serogroups was performed to establish the putative serogroup of the isolated strain. Serovar identification was done by Cross-Agglutination Absorption Test (CAAT). Species determination was carried out on basis of sequence identity of primer pair G1/G2 generated PCR products from the isolate with those from reference strains belonging to the various pathogenic Leptospira species. Results showed that the new strain named, Baires, belongs to species L. interrogans sensu stricto and the serogroup Djasiman. However, the isolate could not be identified as any of the known serovars within this serogroup. These results allow us to conclude that the strain Baires represents a new serovar (Buenos Aires) of Djasiman serogroup.