ABSTRACT
Leptospirosis is a common but underdiagnosed zoonosis. We conducted a 1-year prospective study in La Guaira State, Venezuela, analyzing 71 hospitalized patients who had possible leptospirosis and sampling local rodents and dairy cows. Leptospira rrs gene PCR test results were positive in blood or urine samples from 37/71 patients. Leptospira spp. were isolated from cultured blood or urine samples of 36/71 patients; 29 had L. interrogans, 3 L. noguchii, and 4 L. venezuelensis. Conjunctival suffusion was the most distinguishing clinical sign, many patients had liver involvement, and 8/30 patients with L. interrogans infections died. The Leptospira spp. found in humans were also isolated from local rodents; L. interrogans and L. venezuelensis were isolated from cows on a nearby, rodent-infested farm. Phylogenetic clustering of L. venezuelensis isolates suggested a recently expanded outbreak strain spread by rodents. Increased awareness of leptospirosis prevalence and rapid diagnostic tests are needed to improve patient outcomes.
Subject(s)
Disease Outbreaks , Leptospira , Leptospirosis , Phylogeny , Rodentia , Animals , Leptospirosis/epidemiology , Leptospirosis/veterinary , Leptospirosis/microbiology , Leptospirosis/diagnosis , Humans , Venezuela/epidemiology , Cattle , Leptospira/genetics , Leptospira/isolation & purification , Leptospira/classification , Female , Rodentia/microbiology , Adult , Male , Middle Aged , Cattle Diseases/microbiology , Cattle Diseases/epidemiology , Adolescent , Leptospira interrogans/genetics , Leptospira interrogans/isolation & purification , Leptospira interrogans/classification , Young Adult , Prospective Studies , Child , Aged , Endemic Diseases , Zoonoses/epidemiology , Zoonoses/microbiology , Child, PreschoolABSTRACT
Three strains, CLM-U50T, CLM-R50 and IVIC-Bov1, belonging to the genus Leptospira, were isolated in Venezuela from a patient with leptospirosis, a domestic rat (Rattus norvegicus) and a cow (Bos taurus), respectively. The initial characterisation of these strains based on the rrs gene (16S rRNA) suggested their designation as a novel species within the 'intermediates' group of the genus Leptospira. Further phylogenomic characterisation based on single copy core genes was consistent with their separation into a novel species. The average nucleotide identity between these three strains was >99â%, but below 89â% with respect to any previously described leptospiral species, also supporting their designation as a novel species. Given this evidence, these three isolates were considered to represent a novel species, for which the name Leptospiravenezuelensis sp. nov. is proposed, with CLM-U50T (=CIP 111407T=DSM 105752T) as the type strain.