Abstract:
Understanding the pathogenic status of leptospires, the causative agents of leptospirosis, is important
for successful laboratory diagnosis and control programmes of this zoonosis. Leptospires are difficult
to differentiate morphologically; therefore, their pathogenic, intermediate or saprophytic status is
currently determined based on both phenotypic tests like growth response in medium containing
8-azaguanine and growth at low temperature (13°C), and genotypic methods. The present study reports
on the pathogenic versus saprophytic characterization of nine Leptospira isolates from animal hosts
(rodents and dogs) and humans, with specific interest on a canine isolate coded “Dog109”, which
showed an ambiguous or intermediate status according to conventional (phenotypic) and molecular
(genotypic) tests. The results strongly indicate the need of a polyvalent analytical approach for
improving the differentiation of the pathogenic status of circulating serovars,
