Three novel leptospires isolated from wild animals in the Peruvian Amazon Region of Iquitos.

MICHAEL MATTHIAS; M. MÓNICA DÍAZ; K.J. CAMPOS; ESTRADA, C.; J.N. RICALDI; MICHAEL R. WILLIG; E. GOTUZZO; R.L. GALLOWAY; PAUL LEVETT; ROBERT GILMAN; J.M. VINETZ

Filadelfia, Estados Unidos

Congreso; 2003 Annual Meeting ASTMH (The American Society of Tropical Medicine and Hygiene); 2003

ASTMH (The American Society of Tropical Medicine and Hygiene)

Leptospirosis is particularly prevalent in tropical regions. Iquitos is a jungle city in the Peruvian Amazon, an ideal ecological setting for the maintenance and dissemination of leptospires. To investigate the potential role of wild animals in leptospiral transmission to humans, 258 wild rodents and marsupials were trapped. Kidney tissues were inoculated into semisolid PLM-5 to attempt leptospiral isolation. Isolates were identified presumptively using PFGE fingerprints of NotI restricted genomic DNA and agglutination with reference antisera. Proenchimys spp. (101/40%), Oryzomys spp. (41/16%), Oligoryzomys spp. (29/12%), Marmosops spp. (27/11%) and Philander spp. (23/9%) were obtained. Leptospires were isolated from 6 (2%). Three isolations were made from Proenchimys spp., 2 from Philander spp. and 1 from Didelphis spp. Because culture was likely suboptimal for identifying carriers, we are using a quantitative real time PCR method using an on-site MJ Research DNA Engine Opticon* 2 Continuous Fluorescence Detection System to analyze kidney specimens; these experiments are in progress. There was no association between renal carriage and either habitat or animal sex. PFGE revealed three apparently novel PFGE fingerprints (1 from each mammal genus). Of the other isolates 1 was identified as serovar icterohaemorrhagiae (from Proenchimys). MAT with reference antisera was inconclusive, suggesting the possibility of new serogroups. Of 4 isolates, 3 belonged to new or undesignated serogroups, while the other isolate from Proenchimys spp. belonged to serogroup Djasiman. Pathogenicity of these new isolates remains to be determined; isolates with similar PFGE fingerprints have yet to be obtained from humans. These preliminary investigations suggest the possibility that wild, non-peridomestic rodents and marsupials may play a role in the transmission of leptospirosis in the Peruvian Amazon. Finding novel leptospiral strains carried by wild animals in the Amazon suggests high biodiversity of this genus of bacteria in the region.