Seasonal Increase in the Presence of Leptospira interrogans in Coastal Rivers and 3 Streams of Puerto Rico

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Journal of Environmental Quality


This study aimed to evaluate seasonal shifts in the presence of Leptospira interrogans and the level of Escherichia coli from thirty-two coastal locations in Puerto Rico’s dry and wet seasons. Physichemical parameters (temperature, salinity, pH and dissolved oxygen) were determined at each site. The temperature (25.8 °C) and pH (average 7.6) values were all within acceptable USEPA regulatory standards. 38% of the sites of the dry season and 28% of the wet season sites contained DO levels ≤ 4 mg/L which are relatively low. The level of E. coli at the selected sites were determined using IDEXX ColilertTM18 assay USEPA Standard Method 9223. In the dry season 19 sites and 18 of the wet season sites had E. colicounts above 410 MPN/ 100 ml and would be considered as unsafe for recreational use. The lipl32 gene qPCR assay was used for the detection of pathogenic L. interrogansin the samples. Low concentrations of L. interrogans (less than 60 genome copies/100ml) at Camuy; Espíritu Santo; Río Guayanilla; Quebrada Majagual; and Río Fajardoduring the wet season. L. interroganswere detected at (~ 40 genome copies/100ml) at only one site, Loíza, during the dry season. Spearman’s correlation test, performed with R®program,found no positive relationship between the physiochemical parameters, concentrations of E. coliand the presence of L. interrogans in water samples.


Biological and Environmental Sciences

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