Effects of water turbidity on the survival of Staphylococcus aureus in environmental fresh and brackish waters

Abstract

Staphylococcus aureus is an opportunistic pathogen frequently detected in environmental waters and commonly causes skin infections to water users. S. aureus concentrations in fresh, brackish, and marine waters are positively correlated with water turbidity. To reduce the risk of S. aureus infections from environmental waters, S. aureus survival (stability and multiplication) in turbid waters needs to be investigated. The aim of this study was to measure S. aureus in turbid fresh and brackish water samples and compare the concentrations over time to determine which conditions are associated with enhanced S. aureus survival. Eighteen samples were collected from fresh and brackish water sources from two different sites on the east side of Oʻahu, Hawaiʻi. S. aureus was detected in microcosms for up to 71 days with standard microbial culturing techniques. On average, the greatest environmental concentrations of S. aureus were in high turbidity fresh waters followed by high turbidity brackish waters. Models demonstrate that salinity and turbidity significantly predict environmental S. aureus concentrations. S. aureus persistence over the extent of the experiment was the greatest in high turbidity microcosms with T90's of 147.8 days in brackish waters and 80.8 days in freshwaters. This study indicates that saline, turbid waters, in the absence of sunlight, provides suitable conditions for enhanced persistence of S. aureus communities that may increase the risk of exposure in environmental waters.Practitioner Points Staphylococcus aureus concentrations, survival, and persistence were assessed in environmental fresh and brackish waters. Experimental design preserved in situ conditions to measure S. aureus survival. Higher initial S. aureus concentrations were observed in fresh waters with elevated turbidity, while sustained persistence was greater in brackish waters. Water turbidity and salinity were both positively associated with S. aureus concentrations and persistence. Climate change leads to more intense rainfall events which increase water turbidity and pathogen loading, heightening the exposure risk to S. aureus.

Detection and modeling of Staphylococcus aureus and fecal bacteria in Hawaiian coastal waters and sands

“…Impacts of freshwater input into the coast through groundwater or streams not only lead to increases in coastal water turbidity from washing of fine-grained terrigenous particulates but also can resuspend sand particulates, which may impact concentrations of pathogens in coastal waters and sands (Yamahara et al, 2007). Models demonstrated that water turbidity was positively correlated with seawater concentrations of S. aureus, MRSA, and FIB across all beaches, and this finding is consistent with other studies in Hilo and elsewhere (Cira et al, 2022;Steadmon et al, 2023;Wiegner et al, 2017). Notably, models also demonstrated that tidal height was significantly associated with all bacteria in seawater and sand in which elevated S. aureus and MRSA frequently occurred at higher tidal heights, while FIB were greater at lower tidal heights.…”

Combination of Machine Learning and RGB Sensors to Quantify and Classify Water Turbidity

“…These consequences include impacting aquatic ecosystems by reducing sunlight penetration, disrupting photosynthesis and prey capture, and disturbing the delicate balance of ecosystems. Moreover, suspended particles may serve as carriers for contaminants [7] and benefit the survival of pathogen microorganisms [8], thus amplifying the risk of waterborne diseases. To correctly manage water turbidity requires not only quantifying its presence, but also identifying the specific nature and origin of the suspended particles.…”