Distribution and Diversity of Pathogenic Leptospira Species in Peri-domestic Surface Waters from South Central Chile

Abstract

BackgroundLeptospirosis is a neglected zoonosis affecting animals and humans caused by infection with Leptospira. The bacteria can survive outside of hosts for long periods of time in soil and water. While identification of Leptospira species from human cases and animal reservoirs are increasingly reported, little is known about the diversity of pathogenic Leptospira species in the environment and how surveillance of the environment might be used for monitoring and controlling disease.Methods and FindingsWater samples (n = 104) were collected from the peri-domestic environment of 422 households from farms, rural villages, and urban slums participating in a broader study on the eco-epidemiology of leptospirosis in the Los Rios Region, Chile, between October 2010 and April 2012. The secY region of samples, previously detected as pathogenic Leptospira by PCR, was amplified and sequenced. Sequences were aligned using ClustalW in MEGA, and a minimum spanning tree was created in PHYLOViZ using the goeBURST algorithm to assess sequence similarity. Sequences from four clinical isolates, 17 rodents, and 20 reference strains were also included in the analysis. Overall, water samples contained L. interrogans, L. kirschneri, and L. weilii, with descending frequency. All species were found in each community type. The distribution of the species differed by the season in which the water samples were obtained. There was no evidence that community-level prevalence of Leptospira in dogs, rodents, or livestock influenced pathogen diversity in the water samples.ConclusionsThis study reports the presence of pathogenic Leptospira in the peri-domestic environment of households in three community types and the differences in Leptospira diversity at the community level. Systematic environmental surveillance of Leptospira can be used for detecting changes in pathogen diversity and to identify and monitor contaminated areas where an increased risk of human infection exists.

A systematic review of Leptospira in water and soil environments

“…Studies have identified DNA sequences of Leptospira from the P1 subclade in drinking water (for human or for animals) samples [79][80][81][82]. This suggested a significant health concern and opened the way to consider Leptospira in studies on the potential risks associated with drinking water [83,84].…”

Leptospira and Leptospirosis

“…Saprophytic leptospires are normal inhabitants of freshwater, which do not involve any sanitary risk. However, there has also been evidence of pathogenic leptospires from drinking water for animals (Calderon et al, 2014;Muñoz-Zanzi et al, 2014;Mason et al, 2016;Kurilung et al, 2017), but also for humans (Muñoz-Zanzi et al, 2014;Mason et al, 2016). Very interestingly, a shotgun metagenomics study retrieved a Leptospira spp.…”

Comparison of Leptospira species isolated from environmental water and soil in Japan

“…Reservoir animals shed Leptospira in their urine and humans are infected with the organism by contact with contaminated urine, water, and soil through the skin and mucous membranes . Pathogenic Leptospira have been isolated from patients, reservoir animals, and environmental specimens such as water and soil . However, the abundance of environmental bacteria in water and soil makes isolation difficult.…”

“…2 Pathogenic Leptospira have been isolated from patients, reservoir animals, and environmental specimens such as water and soil. [3][4][5][6] However, the abundance of environmental bacteria in water and soil makes isolation difficult. Chakraborty et al developed a novel selective medium composed of five antimicrobial agents, namely sulfamethoxazole, trimethoprim, amphotericin B, fosfomycin, and 5-fluorouracil, which are abbreviated as STAFF.…”