Seasonal shifts in the presence of pathogenic leptospires, Escherichia coli, and physicochemical properties in coastal rivers and streams of Puerto Rico

Abstract

Leptospirosis is an emerging zoonotic disease in the Caribbean region and the island of Puerto Rico. Information on the presence of pathogenic Leptospira in rivers and streams of Puerto Rico is currently lacking. This study aimed to evaluate seasonal shifts in the presence of pathogenic leptospires and the level of Escherichia coli from 32 coastal locations in Puerto Rico's dry and wet seasons. Physicochemical 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. Thirty-eight percent of the sites of the dry season and 28% of the wet season sites contained dissolved oxygen levels ≤4 mg L −1 , which is relatively low. In the dry season, 19 sites (59%) and 18 (56%) of the wet season sites had E. coli counts >410 most probable number (MPN) 100 ml −1 and would be considered unsafe for recreational use. The lipl32 gene quantitative polymerase chain reaction assay was used for the detection of pathogenic leptospires in the samples. Low concentrations of pathogenic leptospires (<60 genome copies 100 ml −1) at Camuy, Espíritu Santo, Río Guayanilla, Quebrada Majagual, and Río Fajardo were detected during the wet season. Pathogenic leptospires were detected (∼40 genome copies 100 ml −1) at only one site, Loíza, during the dry season. There was no predictable relationship between the physicochemical parameters, concentrations of E. coli, and the presence of pathogenic leptospires in water samples.

Spatial-temporal targeted and non-targeted surveys to assess microbiological composition of drinking water in Puerto Rico following Hurricane Maria

“…( Keenum et al., 2021 ), possibly due to the efficacy of routine disinfection practices in the elimination of this pathogen ( Wynwood et al., 2014 ). However, its importance has been highlighted in rivers and creeks when used as drinking water without proper treatment, particularly in situations of water scarcity, such as hurricanes ( Keenum et al., 2021 ; Truitt et al., 2020 ). The presence of Leptospira in GUA is possibly exacerbated by the absence of residual chlorine at this location.…”

Spatiotemporal Assessment of Pathogenic Leptospira in Subtropical Coastal Watersheds

“…The assay's lower detection limit was determined using positive control DNA serial dilutions. Variations in quanti cation cycle (Cq) values between a sample and its 10-fold dilution were analyzed to identify potential PCR inhibitors (Ahmed et al, 2020;Truitt et al, 2020). Only PCRs with an e ciency of > 90% were considered acceptable.…”

“…Leptospirosis is a growing threat to global public health, manifesting as an emerging and prevalent zoonotic disease in tropical and subtropical areas (Truitt et al, 2020;Karpagam & Ganesh, 2020;Hartskeerl et al, 2011;Vijayachari et al, 2008;Dhewantara et al, 2019;Haake & Levett, 2015). Leptospirosis contributes to an estimated 60,000 deaths annually globally (Costa et al, 2015).…”

“…This task has been made achievable with the application of qPCR techniques, the rapid detection of Leptospira in environmental matrices, and the identi cation of likely sources (Bachoon et al, 2010;Rawlins et al, 2014;Riediger et al, 2016). This was con rmed by successfully implementing a hydrolysis probe qPCR assay targeting the LipL32 gene (Stoddard et al, 2009;Rawlins et al, 2014;Truitt et al, 2020). The technique permits the robust detection and characterization of pathogenic Leptospira spp.…”

Spatial-temporal targeted and non-targeted surveys to assess microbiological composition of drinking water in Puerto Rico following Hurricane Maria

“…However, its importance has been highlighted in rivers and creeks when used as drinking water without proper treatment, particularly in situations of water scarcity, such as hurricanes (Keenum et al, 2021;Truitt et al, 2020). The presence of Leptospira in GUA is possibly exacerbated by the absence of residual chlorine at this location.…”