Isolation and identifcation of Leptospira from the urine of dogs with suspected leptospirosis in Can Tho city

Abstract

leptospirosis is a popularly zoonotic disease of the worldwide. The sero-prevalence of leptospirosis
was reported in the domestic dogs in the Mekong Delta. Recently, the dogs suspecting leptospirosis
with the clinical syndromes, such as: jaundice, mucosal hemorrhage, oculo-nasal discharge, abdominal
pain and renal dysfunction were recorded in the veterinary clinics in the investigating area. The objective
of this study was to detect the Leptospira species causing leptospirosis in the dogs. One hundred
and eleven (111) urine samples were collected from the suspected dogs to detect the presence of
leptospira by a dark-field microscopy; leptospira from the positive samples was inoculated in the EMJH
medium, then Leptospira species were identified by PCR assay, and 16S rRNA gene sequence.
The results of dark-field microscopic examination showed that leptospira was present in 63 out of
111 (56.75%) urine samples, however leptospira was cultured successfully on EMJH medium from
only 3 out of 63 positive urine samples, accounting for 4.76%. The results of analysing leptospira gene
sequences revealed two species, i.e. Leptospira interrogans and Leptospira fainei presenting in the
urine of the investigated dogs, of which L. interrogans belonged to the mainly pathogenic group and L.
fainei belonged to the associated pathogenic group. This is the first successful study on isolation and
identification of pathogenic Leptospira from the urine of the dogs suspecting leptospirosis in Viet Nam