Research Publication Title

Non-Point Source Fecal Contamination linked to Deadly Pathogenic Leptospira in Puerto Rico Rivers

Presenter Information

Zamara R. Garcia TruittFollow

Major

Masters in Science

Faculty Mentor

Dr. Dave Bachoon

Keywords

qPCR, Leptospira, pollution, water samples

Abstract

It is estimated that there are over 1.03 million cases of leptospirosis and 48, 000 deaths from this disease each year. A total of 64 freshwater sites located across streams and rivers of coastal locations across Puerto Rico were sampled during both the wet and dry seasons in 2014. Spiral-shaped pathogenic Leptospira bacteria found in the urine of rodents and other small mammal species tend to spread after floods through drinking water or infection of open wounds, which can lead to death in some people. Puerto Rico has reported at least 76 cases of suspected and confirmed leptospirosis, including a handful of deaths in the months after Hurricane Irma 2017. Real-time PCR was used to identify the source of fecal contamination through molecular source tracking (MST) techniques and detect the presence of the pathogenic Leptospira in rivers. The source of the pathogen was traced using probe-based Taqman qPCR assays targeting of Bacteroides human-specific (HF183) marker, a ruminant-specific (BacCowP) gene. The human-specific HF183 assay detected the presence of human fecal contamination in 23.4%, 25% of the sites had ruminant fecal contamination. Low concentrations of L. interrogans (less than 60 genome copies/100ml) at Camuy; Espíritu Santo; Río Guayanilla; Quebrada Majagual; and Río Fajardo during the wet season. L. interrogans were detected at (~ 40 genome copies/100ml) at only one site, Loíza, during the dry season. As global warming continues and the frequency of hurricanes affecting Puerto Rico increases it is likely that there will be an more cases of Leptospirosis reported on the island.

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Non-Point Source Fecal Contamination linked to Deadly Pathogenic Leptospira in Puerto Rico Rivers

It is estimated that there are over 1.03 million cases of leptospirosis and 48, 000 deaths from this disease each year. A total of 64 freshwater sites located across streams and rivers of coastal locations across Puerto Rico were sampled during both the wet and dry seasons in 2014. Spiral-shaped pathogenic Leptospira bacteria found in the urine of rodents and other small mammal species tend to spread after floods through drinking water or infection of open wounds, which can lead to death in some people. Puerto Rico has reported at least 76 cases of suspected and confirmed leptospirosis, including a handful of deaths in the months after Hurricane Irma 2017. Real-time PCR was used to identify the source of fecal contamination through molecular source tracking (MST) techniques and detect the presence of the pathogenic Leptospira in rivers. The source of the pathogen was traced using probe-based Taqman qPCR assays targeting of Bacteroides human-specific (HF183) marker, a ruminant-specific (BacCowP) gene. The human-specific HF183 assay detected the presence of human fecal contamination in 23.4%, 25% of the sites had ruminant fecal contamination. Low concentrations of L. interrogans (less than 60 genome copies/100ml) at Camuy; Espíritu Santo; Río Guayanilla; Quebrada Majagual; and Río Fajardo during the wet season. L. interrogans were detected at (~ 40 genome copies/100ml) at only one site, Loíza, during the dry season. As global warming continues and the frequency of hurricanes affecting Puerto Rico increases it is likely that there will be an more cases of Leptospirosis reported on the island.