Leptospirosis is a zoonosis of worldwide distribution in tropical and subtropical countries. The etiological agent is of bacterial origin and belongs to the order Spirochaetales and the genus Leptospira spp. This disease is endemic in Argentina and in addition to its public health importance, it is responsible for huge economic losses to the agroindustry. Indeed, 10% of the abortions in bovines caused by bacteria are estimated to be due to infections with pathogenic leptospiral strains 14, these are disseminated into the environment through urine of infected animals and reservoirs and have the ability to survive in the ecosystem (water bodies, mud and sand) during days, weeks and even months, these strains mainly infect mammals, but they can also be found in reptiles and amphibians. 1, 7,8
In a recent study of genus wide Leptospira spp. core genome MLST (cgMLST), 35 species are reported (13 species belonging to the pathogenic clade, 11 to the intermediate and saprophyte likewise)13.These clades are divided regarding their virulence and manifestation of symptoms, being the pathogenic clade the most virulent. In Argentina, several studies on taxonomy and molecular typing have been done, reporting in some cases new hosts (reservoirs) and new strains isolated from wildlife 2,5,9,11,12, domestic animals 10,12, 14 and also from water samples. 8, 21 These studies allow to conclude that the pathogenic strains of Leptospira spp. present in Argentina include: Leptospira interrogans of the serovars Pomona (four genotypes: A,B.C.D), L. interrogans serovar Canicola Hond Utrecht IV, and serovar Portlandvere MY1039, L. interrogans serovar Icterohaemorrhagiae RGA, and Ictero I, serovar Coppenhageni M20, L. borgpetersenii serovar Castellon Castellonis and serovar Hardjobovis 5,10,12,14,17
The Guanaco (Lama guanicoe) is a South American Camelid (SAC) that is either wild or raised under silvestry conditions in Patagonia and other regions of Argentina and shares pastures with bovines and other production animals 3. The SACs are composed also by Lama glama, Lama pacos and Vicugna vicugna. In the last decade, studies on its biology and ecology have intensified to impulse the development of alternative regional economies. Previous studies on serosurveys of SAC in the region (Perú), show positive titres (1:100 to 1:1600) to L. interrogans serovar Icterohaemorrhagiae and L. interrogans serovar Pomona in Alpacas and lower titres (1:100 to 1:400) in Vicuñas reacting to the same serovars.19 Serosurveys done on SACs in Argentina, show 60% of seroprevalence (Buenos Aires Province) being the serovars Icterohaemorrhagiae, Pomona and Grippotyphosa most reactive3. In another study (Jujuy Province) 96,2% show seroreactivity being serovars Copenhagni (serogroup Icterohaemorrhagiae), and Castellonis (belonging to the serogroup Ballum) the most reactive serovars16.
Serovar Hardjobovis (belonging to the species L. borgpetersenii) is the most adapted serovar to bovine hosts and is the most prevalent serovar in bovines worldwide 1,7. Also, this serovar is not distinguishable using serological tools within serovar Hardjo (L. interrogans strain Hardjoprajitno). However, some molecular tools can be used to differentiate these serovares. In this study the typing scheme of Multiple Locus Variable Number Tandem Repeats Analysis (MLVA) 20 and sequencing of partial 16S rRNA was used to genotype this strain to confirm this genotype. In a recent study, this serovar was molecularly typed using MLVA from clinical cases in bovines in Argentina.14
To the best of our knowledge this is the first isolation of a pathogenic leptospiral strain in Guanacos in South America. The purpose of this study was to molecularly characterize the isolated strain from kidney subsamples of Guanacos (L. guanicoe) from Argentina.