1. Kelly, E.A., Z. Feng, M.L. Gidley, C.D. Sinigalliano, N. Kumar, A.G. Donahue, and A.J.H.M. Reniers. Effect of beach management policies on recreational water quality. Journal of Environmental Management, 212:266-277, doi:10.1016/j.jenvman.2018.02.012 2018


    When beach water monitoring programs identify poor water quality, the causes are frequently unknown. We hypothesize that management policies play an important role in the frequency of fecal indicator bacteria (FIB) exceedances (enterococci and fecal coliform) at recreational beaches. To test this hypothesis we implemented an innovative approach utilizing large amounts of monitoring data (n > 150,000 measurements per FIB) to determine associations between the frequency of contaminant exceedances and beach management practices. The large FIB database was augmented with results from a survey designed to assess management policies for 316 beaches throughout the state of Florida. The FIB and survey data were analyzed using t-tests, ANOVA, factor analysis, and linear regression. Results show that beach geomorphology (beach type) was highly associated with exceedance of regulatory standards. Low enterococci exceedances were associated with open coast beaches (n = 211) that have sparse human densities, no homeless populations, low densities of dogs and birds, bird management policies, low densities of seaweed, beach renourishment, charge access fees, employ lifeguards, without nearby marinas, and those that manage storm water. Factor analysis and a linear regression confirmed beach type as the predominant factor with secondary influences from grooming activities (including seaweed densities and beach renourishment) and beach access (including charging fees, employing lifeguards, and without nearby marinas). Our results were observable primarily because of the very large public FIB database available for analyses; similar approaches can be adopted at other beaches. The findings of this research have important policy implications because the selected beach management practices that were associated with low levels of FIB can be implemented in other parts of the US and around the world to improve recreational beach water quality.

  2. Staley, C., T. Kaiser, M.L. Gidley, I.C. Enochs, P.R. Jones, K.D. Goodwin, C.D. Sinigalliano, M.J. Sadowsky, and C.L. Chun. A next-generation sequencing approach to characterize the impacts of land-based sources of pollution on the microbiota of southeast Florida coral reefs. Applied and Environmental Microbiology, 83(10):e03378-16, doi:10.1128/AEM.03378-16 2017


    Coral reefs are dynamic ecosystems known for decades to be endangered due, in large part, to anthropogenic impacts from land-based sources of pollution (LBSP). In this study, we utilized an Illumina-based next-generation sequencing approach to characterize prokaryotic and fungal communities from samples collected off the southeast coast of Florida. Water samples from coastal inlet discharges, oceanic outfalls of municipal wastewater treatment plants, treated wastewater effluent before discharge, open ocean samples, and coral tissue samples (mucus and polyps) were characterized to determine relationships between microbial communities in these matrices and those in reef water and coral tissues. Significant differences in microbial communities were noted among all sample types but varied between sampling area. Contamination from outfalls was found to be the greatest potential source of LBSP influencing native microbial community structure among all reef samples, although pollution from inlets was also noted. Notably, reef water and coral tissue communities were found to be more greatly impacted by LBSP at southern reefs, which also experienced the most degradation during the course of the study. Results of this study provide new insights into how microbial communities from LBSP can impact coral reefs in Southeast Florida and suggest that wastewater outfalls may have a greater influence on the microbial diversity and structure of these reef communities than do contaminants carried in runoff although the influence of runoff and coastal inlet discharge on coral reefs are still substantial.

  3. Symonds, E.M., C. Sinigalliano, M. Gidley, W. Ahmed, S.M. McQaig-Ulrich, and M. Breitbart. Fecal pollution along the southeastern coast of Florida and insight into the use of pepper mild mottle virus as an indicator. Journal of Applied Microbiology, 121(5):1469-1481, doi:10.1111/mam.13252 2016


    In 2014, bimonthly surface water samples were collected from inlets, exposed to runoff and septic seepage, and coastal sites, exposed to ocean outfalls. Analysis of culturable enterococci and a suite of microbial source tracking (MST) markers (BacHum, CowM2, DogBact, HF183, HPyV, PMMoV) revealed fecal pollution, primarily of human origin, at all sites. Since PMMoV was detected more frequently than other MST markers, the process limits of quantification (undiluted to 10−2 dilution) and detection (10−2 dilution) for the RT-qPCR method were determined by seeding untreated wastewater into the coastal waters. Simulated quantitative microbial risk assessment, employing human norovirus as a reference pathogen, calculated a 0·286 median risk of gastrointestinal illness associated with the PMMoV limit of detection. This study demonstrated that PMMoV is an important domestic wastewater-associated marker that should be included in the MST toolbox; therefore, future studies should thoroughly investigate the health risks associated with its detection and quantification in environmental waters.

  4. Carsey, T.P., S.J. Stamates, C.M. Featherstone, N. Amornthammarong, J.R. Bishop, C.J. Brown, A. Campbell, H.L. Casanova, M.L. Gidley, M. Kosenko, R.M. Kotkowski, J.V. Lopez, C.D. Sinagalliano, L.A. Visser, and J.-Z. Zhang. Broward County coastal ocean water quality study, 2010-2012. NOAA Technical Report, OAR-AOML-44, 217 pp., doi:10.7289/V5TD9VCC 2015


    Researchers with the Ocean Chemistry and Ecosystems Division of NOAA’s Atlantic Oceanographic and Meteorological Laboratory conducted 12 monthly cruises in two separate track lines off of Broward County, Florida, from November 2010 through January 2012. The cruise tracks were designed to provide information on three categories of the coastal ocean: (1) the vicinity of the Broward and Hollywood treated-wastewater outfalls; (2) the vicinity of the Hillsboro and Port Everglades inlets; and (3) the interstitial areas in between. Sampling took place from aboard the NOAA R/V Hildebrand using a conductivity-temperature-depth (CTD)/rosette for water samples and water column profiles and appropriately located acoustic Doppler current profiler (ADCP) instruments for ocean current information. Measured discrete parameters included location, depth, salinity, temperature, pH, oxygen saturation (dissolved oxygen, DO), oxidation-reduction (redox) potential (ORP), chlorophyll-a, phaeopigments, total suspended solids (TSS), nitrate (NO3), nitrite (NO2), ammonium (NH4), silicate (Si), orthophosphate (PO4), total dissolved nitrogen (TDN), total dissolved phosphorus (TDP), particulate carbon (PC), particulate phosphorus (PP), particulate nitrogen (PN), and dissolved organic carbon (DOC). CTD profile data included depth, turbidity, ORP, DO, pH, chlorophyll-a, salinity, temperature, and density. A variety of microbiological entities were measured, including fecal indicator bacteria (FIB), selected waterborne pathogens, and molecular microbial source tracking (MST) markers. Community bacterial metagenomic profiles were also generated for selected sample sites. Quality controls of nutrient sample analyses were obtained following National Environmental Laboratory Accreditation Conference (NELAC)-certified procedures. The data obtained present a view of the coastal ocean as having a low “background” concentration of most analytes, interrupted by elevated concentrations near the outfalls and inlets whose excess concentrations decreased rapidly away from the point sources. The waters were found to be oligotrophic, with no evidence of bloom events. A major upwelling event was observed on August 11, 2011, where a ~10°C temperature drop was observed near the southernmost portion of the sampled area.

  5. Hower, S., M.C. Phillips, M. Brodsky, A. Dameron, M.A. Tamargo, N.C. Salazar, C.R. Jackson, J.B. Barrett, M. Davidson, J. Davis, S. Mukherjee, R.Y. Ewing, M.L. Gidley, C.D. Sinigalliano, L. Johns, F.E. Johnson, O. Adebanjo, and L.W.R. Plano. Clonally related methicillin-resistant Staphylococcus aureus isolated from short-finned pilot whales (Globicephala macrorhynchus), human volunteers, and a bayfront cetacean rehabilitation facility. Microbial Ecology, 65(4):1024-1038, doi:10.1007/s00248-013-0178-3 2013


    In May of 2011, a live mass stranding of 26 short-finned pilot whales (Globicephala macrorhynchus) occurred in the lower Florida Keys. Five surviving whales were transferred from the original stranding site to a nearby marine mammal rehabilitation facility where they were constantly attended to by a team of volunteers. Bacteria cultured during the routine clinical care of the whales and necropsy of a deceased whale included methicillin-sensitive and methicillin-resistant Staphylococcus aureus (MSSA and MRSA). In order to investigate potential sources or reservoirs of MSSA and MRSA, samples were obtained from human volunteers, whales, seawater, and sand from multiple sites at the facility, nearby recreational beaches, and a canal. Samples were collected on 3 days. The second collection day was 2 weeks after the first, and the third collection day was 2 months after the last animal was removed from the facility. MRSA and MSSA were isolated on each day from the facility when animals and volunteers were present. MSSA was found at an adjacent beach on all three collection days. Isolates were characterized by utilizing a combination of quantitative real-time PCR to determine the presence of mecA and genes associated with virulence, staphylococcal protein A typing, staphylococcal cassette chromosome mec typing, multilocus sequence typing, and pulsed field gel electrophoresis (PFGE). Using these methods, clonally related MRSA were isolated from multiple environmental locations as well as from humans and animals. Non-identical but genetically similar MSSA and MRSA were also identified from distinct sources within this sample pool. PFGE indicated that the majority of MRSA isolates were clonally related to the prototype human strain USA300. These studies support the notion that S. aureus may be shed into an environment by humans or pilot whales and subsequently colonize or infect exposed new hosts.

  6. Layton, B.A., Y. Cao, D.L. Ebentier, K. Hanley, E. Balleste, J. Brandao, M. Byappanahalli, R. Converse, A.H. Farnleitner, J. Gentry-Shields, M.L. Gidley, M. Gourmelon, C.S. Lee, J. Lee, S. Lozach, T. Madi, W.G. Meijer, R. Noble, L. Peed, G.H. Reischer, R. Rodrigues, J.B. Rose, A. Schriewer, C.D. Sinigalliano, S. Srinivasan, J. Stewart, L.C. Van De Werfhorst, D. Wang, R. Whitman, S. Wuertz, J. Jay, P.A. Holden, A.B. Boehm, O. Shanks, and J.F. Griffith. Performance of human fecal anaerobe-associated PCR-based assays in a multi-laboratory method evaluation study. Water Research, 47(18):6897-6908, doi:10.1016/j.watres.2013.05.060 2013


    A number of PCR-based methods for detecting human fecal material in environmental waters have been developed over the past decade, but these methods have rarely received independent comparative testing in large multi-laboratory studies. Here, we evaluated ten of these methods (BacH, BacHum-UCD, B. thetaiotaomicron (BtH), BsteriF1, gyrB, HF183 endpoint, HF183 SYBR, HF183 Taqman, HumM2, and M. smithii nifH (Mnif)) using 64 blind samples prepared in one laboratory. The blind samples contained either one or two fecal sources from human, wastewater or non-human sources. The assay results were assessed for presence/absence of the human markers and also quantitatively while varying the following: (1) classification of samples that were detected but not quantifiable (DNQ) as positive or negative; (2) reference fecal sample concentration unit of measure (such as culturable indicator bacteria, wet mass, total DNA, etc.); and (3) human fecal source type (stool, sewage or septage). Assay performance using presence/absence metrics was found to depend on the classification of DNQ samples. The assays that performed best quantitatively varied based on the fecal concentration unit of measure and laboratory protocol. All methods were consistently more sensitive to human stools compared to sewage or septage in both the presence/absence and quantitative analysis. Overall, HF183 Taqman was found to be the most effective marker of human fecal contamination in this California-based study.

  7. Plano, L.R.W., T. Shibata, A.C. Garza, J. Kish, J.M. Fleisher, C.D. Sinigalliano, M.L. Gidley, K. Withum, S.M. Elmir, S. Hower, C.R. Jackson, J.B. Barrett, T. Cleary, M. Davidson, J. Davis, S. Mukherjee, L.E. Fleming, and H.M. Solo-Gabriele. Human-associated methicillin-resistant Staphylococcus aureus from a subtropical recreational marine beach. Microbial Ecology, 65(4):1039-1051, doi:10.1007/s00248-013-0216-1 2013


    Reports of Staphylococcus aureus including methicillin-resistant S. aureus (MRSA) detected in marine environments have occurred since the early 1990s. This investigation sought to isolate and characterize S. aureus from marine waters and sand at a subtropical recreational beach, with and without bathers present, in order to investigate possible sources and to identify the risks to bathers of exposure to these organisms. During 40 days over 17 months, 1,001 water and 36 intertidal sand samples were collected by either bathers or investigators at a subtropical recreational beach. Methicillin-sensitive S. aureus (MSSA) and MRSA were isolated and identified using selective growth media and an organism-specific molecular marker. Antimicrobial susceptibility, staphylococcal cassette chromosome mec (SCCmec) type, pulsed-field gel electrophoresis (PFGE) pattern, multi-locus sequence type (MLST), and staphylococcal protein A (spa) type were characterized for all MRSA. S. aureus was isolated from 248 (37%) bather nearby water samples at a concentration range of <2-780 colony forming units per ml, 102 (31%) ambient water samples at a concentration range of <2-260 colony forming units per ml, and 9 (25%) sand samples. Within the sand environment, S. aureus was isolated more often from above the intertidal zone than from intermittently wet or inundated sand. A total of 1334 MSSA were isolated from 37 sampling days and 22 MRSA were isolated from ten sampling days. Seventeen of the 22 MRSA were identified by PFGE as the community-associated MRSA USA300. MRSA isolates were all SCCmec type IVa, encompassed five spa types (t008, t064, t622, t688, and t723), two MLST types (ST8 and ST5), and 21 of 22 isolates carried the genes for Panton–Valentine leukocidin. There was a correlation (r = 0.45; p = 0.05) between the daily average number of bathers and S. aureus in the water; however, no association between exposure to S. aureus in these waters and reported illness was found. This report supports the concept that humans are a potential direct source for S. aureus in marine waters.

  8. Stamates, S.J., P.L. Blackwelder, C.J. Brown, T.P. Carsey, C.M. Featherstone, M.L. Gidley, C.R. Kelble, R.M. Kotkowski, and R.J. Roddy. Biscayne Bay turbidity study. NOAA Technical Report, OAR-AOML-41, 65 pp., 2013


    No abstract.

  9. Enns, A.A., L.J. Vogel, A.M. Abdelzaher, H.M. Solo-Gabriele, L.R.W. Plano, M.L. Gidley, M.C. Phillips, J.S. Klaus, A.M. Piggot, Z. Feng, A.J.H.M. Reniers, B.K. Haus, S.M. Elmir, Y. Zhang, N.H. Jimenez, N. Abdel-Mottaleb, M.E. Schoor, A. Brown, S.Q. Khan, A.S. Dameron, N.C. Salazar, and L.E. Fleming. Spatial and temporal variation in indicator microbe sampling is influential in beach management decisions. Water Research, 46(7):2237-2246, doi:10.1016/ j.watres.2012.01.040 2012

    Abstract: Fecal indicator microbes, such as enterococci, are often used to assess potential health risks caused by pathogens at recreational beaches. Microbe levels often vary based on collection time and sampling location. The primary goal of this study was to assess how spatial and temporal variations in sample collection, which are driven by environmental parameters, impact enterococci measurements and beach management decisions. A secondary goal was to assess whether enterococci levels can be predictive of the presence of Staphylococcus aureus, a skin pathogen. Over a ten day period, hydrometeorologic data, hydrodynamic data, bather densities, enterococci levels, and S. aureus levels including methicillin-resistant S. aureus (MRSA) were measured in both water and sand. Samples were collected hourly for both water and sediment at knee-depth, and every 6 hours for water at waist-depth, supratidal sand, intertidal sand, and waterline sand. Results showed that solar radiation, tides, and rainfall events were major environmental factors that impacted enterococci levels. S. aureus levels were associated with bathing load, but did not correlate with enterococci levels or any other measured parameters. The results imply that frequencies of advisories depend heavily upon sample collection policies due to spatial and temporal variation of enterococci levels in response to environmental parameters. Thus, sampling at different times of the day and at different depths can significantly impact beach management decisions. Additionally, the lack of correlation between S. aureus and enterococci suggests that use of fecal indicators may not accurately assess risk for some pathogens.

  10. Abdelzaher, A.A., M.E. Wright, C. Ortega, A.R. Hasan, T. Shibata, H.M. Solo-Gabriele, J. Kish, K. Withum, G. He, S.M. Elmir, J.A. Bonilla, T.D. Bonilla, C.J. Palmer, T.M. Scott, J. Lukasik, V.J. Harwood, S. McQuaig, C.D. Sinigalliano, M.L. Gidley, D. Wanless, L.R.W. Plano, A.C. Garza, X. Zhu, J.R. Stewart, J.W. Dickerson, H. Yampara-Iquise, C. Carson, J.M. Fleisher, and L.E. Fleming. Daily measures of microbes and human health at a non-point source marine beach. Journal of Water and Health, 9(3):443-457, doi:10.2166/wh.2011.146 2011

    Abstract: Studies evaluating the relationship between microbes and human health at non-point source beaches are necessary for establishing criteria which would protect public health while minimizing economic burdens. The objective of this study was to evaluate water quality and daily cumulative health effects (gastrointestinal, skin, and respiratory illnesses) for bathers at a non-point source subtropical marine recreational beach in order to better understand the inter-relationships between these factors and hence improve monitoring and pollution prevention techniques. Daily composite samples were collected, during the Oceans and Human Health Beach Exposure Assessment and Characterization Health Epidemiologic Study conducted in Miami (Florida, USA) at a non-point source beach, and analyzed for several pathogens, microbial source tracking markers, indicator microbes, and environmental parameters. Analysis demonstrated that rainfall and tide were more influential, when compared to other environmental factors and source tracking markers, in determining the presence of both indicator microbes and pathogens. Antecedent rainfall and F+ coliphage detection in water should be further assessed to confirm their possible association with skin and GI illness outcomes, respectively. The results of this research illustrate the potential complexity of beach systems characterized by non-point sources, and how more novel and comprehensive approaches are needed to assess beach water quality for the purpose of protecting bather health.

  11. Plano, L.R.W., A. Garza, T. Shibata, S.M. Elmir, J. Kish, C.D. Sinigalliano, M.L. Gidley, G. Miller, K. Withum, L.E. Fleming, and H.M. Solo-Garbriele. Shedding of Staphylococcus aureus and methicillin-resistant Staphylococcus aureus from adult and pediatric bathers in marine waters. BMC Microbiology, 11:5, 10 pp., doi:10.1186/1471-2180-11-5 2011

    Abstract: Staphylococcus aureus including methicillin resistant S. aureus, MRSA, are human colonizing bacteria that commonly cause opportunistic infections primarily involving the skin in otherwise healthy individuals. These infections have been linked to close contact and sharing of common facilities such as locker rooms, schools, and prisons. Waterborne exposure and transmission routes have not been traditionally associated with S. aureus infections. Coastal marine waters and beaches used for recreation are potential locations for the combination of high numbers of people with close contact and, therefore, could contribute to the exposure to and infection by these organisms. The primary aim of this study was to evaluate the amount and characteristics of the shedding of methicillin sensitive S. aureus, MSSA and MRSA by human bathers in marine waters. Nasal cultures were collected from bathers, and water samples were collected from two sets of pools designed to isolate and quantify MSSA and MRSA shed by adults and toddlers during exposure to marine water. A combination of selective growth media and biochemical and polymerase chain reaction analysis was used to identify and perform limited characterization of the S. aureus isolated from the water and the participants. Twelve of 15 MRSA isolates collected from the water had identical genetic characteristics as the organisms isolated from the participants exposed to that water, while the remaining 3 MRSA were without matching nasal isolates from participants. The amount of S. aureus shed per person corresponded to 105 to 106 CFU per person per 15-minute bathing period, with 15 to 20% of this quantity testing positive for MRSA. This is the first report of a comparison of human colonizing organisms with bacteria from human exposed marine water attempting to confirm that participants shed their own colonizing MSSA and MRSA into their bathing milieu. These findings clearly demonstrate that adults and toddlers shed their colonizing organisms into marine waters and, therefore, can be sources of potentially pathogenic S. aureus and MRSA in recreational marine waters. Additional research is needed to evaluate recreational beaches and marine waters as potential exposure and transmission pathways for MRSA.

  12. Shah, A.H., A.M. Abdelzaher, M. Phillips, R. Hernandez, H.M. Solo-Gabriele, J. Kish, G. Scorzetti, J.W. Fell, M.R. Diaz, T.M. Scott, J. Lukasik, V.J. Harwood, S. McQuaig, C.D. Sinigalliano, M.L. Gidley, D. Wanless, A. Agar, J. Lui, J.R. Stewart, L.R.W. Plano, and L.E. Fleming. Indicator microbes correlate with pathogenic bacteria, yeast, and helminthes in sand at a subtropical recreational beach site. Journal of Applied Microbiology, 110(6):1571-1583, doi:10.1111/j.1365-2672.2011.05013.x. 2011

    Abstract: Research into the relationship between pathogens, fecal indicator microbes, and environmental factors in beach sand has been limited, yet vital to the understanding of the microbial relationship between sand and the water column and to the improvement of criteria for better human health protection at beaches. The objectives of this study were to evaluate the presence and distribution of pathogens in various zones of beach sand (subtidal, intertidal, and supratidal) and to assess their relationship with environmental parameters and indicator microbes at a non-point source subtropical marine beach. In this exploratory study in subtropical Miami (Florida, USA), beach sand samples were collected and analyzed over the course of 6 days for several pathogens, microbial source tracking markers, and indicator microbes. An inverse correlation between moisture content and most indicator microbes was found. Significant associations were identified between some indicator microbes and pathogens (such as nematode larvae and yeasts in the genus Candida), which are from classes of microbes that are rarely evaluated in the context of recreational beach use. Results indicate that indicator microbes may predict the presence of some of the pathogens, in particular helminthes, yeasts, and the bacterial pathogen Staphylococcus aureus including methicillin-resistant forms. Indicator microbes may thus be useful for monitoring beach sand and water quality at non-point source beaches. The presence of both indicator microbes and pathogens in beach sand provides one possible explanation for human health effects reported at non-point sources beaches.

  13. Abdelzaher, A.M., M.E. Wright, C. Ortega, H.M. Solo-Gabriele, G. Miller, S. Elmir, X. Newman, P. Shih, J.A. Bonilla, T.D. Bonilla, C.J. Palmer, T. Scott, J. Lukasik, V.J. Harwood, S. McQuaig, C. Sinigalliano, M. Gidley, L.R.W. Plano, X. Zhu, J.D. Wang, and L.E. Fleming. Presence of pathogens and indicator microbes at a non-point source subtropical recreational marine beach. Applied and Environmental Microbiology, 76(3):724-732, doi:10.1128/AEM.02127-09 2010

    Abstract: Swimming in ocean water, including ocean water at beaches not impacted by known point sources of pollution, is an increasing health concern. This study was an initial evaluation of the presence of indicator microbes and pathogens and the association among the indicator microbes, pathogens, and environmental conditions at a subtropical, recreational marine beach in south Florida impacted by non-point sources of pollution. Twelve water and eight sand samples were collected during four sampling events at high or low tide under elevated or reduced solar insolation conditions. The analyses performed included analyses of fecal indicator bacteria (FIB) (fecal coliforms, Escherichia coli, enterococci, and Clostridium perfringens), human-associated microbial source tracking (MST) markers (human polyomaviruses [HPyVs] and Enterococcus faecium esp gene), and pathogens (Vibrio vulnificus, Staphylococcus aureus, enterovirus, norovirus, hepatitis A virus, Cryptosporidium spp., and Giardia spp.). The enterococcus concentrations in water and sand determined by quantitative PCR were greater than the concentrations determined by membrane filtration measurement. The FIB concentrations in water were below the recreational water quality standards for three of the four sampling events, when pathogens and MST markers were also generally undetectable. The FIB levels exceeded regulatory guidelines during one event, and this was accompanied by detection of HPyVs and pathogens, including detection of the autochthonous bacterium V. vulnificus in sand and water, detection of the allochthonous protozoans Giardia spp. in water, and detection of Cryptosporidium spp. in sand samples. The elevated microbial levels were detected at high tide and under low-solar-insolation conditions. Additional sampling should be conducted to further explore the relationships between tidal and solar insolation conditions and between indicator microbes and pathogens in subtropical recreational marine waters impacted by non-point source pollution.

  14. Fleisher, J.M., L.E. Fleming, H.M. Solo-Gabriele, J.K. Kish, C.D. Sinigalliano, L.W. Plano, S.M. Elmir, J.D. Wang, K.F. Withum, T. Shibata, M.L. Gidley, A. Abdelzaher, G. He, C. Ortega, X. Zhu, M.D. Wright, J.A. Hollenbeck, and L.C. Backer. The BEACHES Study: Health effects and exposures from nonpoint source microbial contaminants in subtropical recreational marine waters. International Journal of Epidemiology, 39(5):1291-1298, doi:10.1093/ije/dyq084 2010

    Abstract: Microbial water quality indicators, found in high concentrations in sewage, are used to determine whether water is safe for recreational purposes. Recently, concerns have been raised about the appropriate use of indicators to regulate recreational water bodies, particularly non-point source sub/tropical recreational marine waters. A group of 1303 adult regular bathers were randomly assigned to bather and non-bather groups, with subsequent follow-up for reported illness, in conjunction with an ongoing extensive environmental sampling of indicator organisms (enterococcus) and pathogens. After controlling for non-water related risk factors/possible confounders, bathers were 1.75 times (95% confidence interval = 0.94-3.26; p = 0.078) more likely to report gastrointestinal illness relative to non bathers; bathers were 4.46 times (0.99-20.97; p = 0.051) more likely to report acute febrile respiratory illness; and bathers were 5.51 times (2.68-11.36; p = 0.<0.0001) more likely to report skin illness relative to non-bathers after seven days of follow up from beach exposure. There was an apparent dose-response relationship between bather exposure to increasing levels of enterococcus and risks of reported skin and gastrointestinal illness, and some evidence of increased risk of respiratory illness among bathers relative to nonbathers. There was a possible threshold effect for gastrointestinal illness at approximately 40 CFU/100 mL of enterococcus; however, no threshold effect was observed for skin illness. Human exposures to and health risks from microbial pollution may occur even in a non-point source recreational marine environment.

  15. Shibata, T., H.M. Solo-Gabriele, C.D. Sinigalliano, M.L. Gidley, L.R.W. Plano, J.M. Fleisher, J.D. Wang, S.M. Elmir, G. He, M.E. Wright, A.M. Abdelzaher, C. Ortega, D. Wanless, A.C. Garza, J. Kish, T. Scott, J. Hollenbeck, L.C. Backer, and L.E. Fleming. Evaluation of conventional and alternative monitoring methods for a recreational marine beach with nonpoint source of fecal contamination. Environmental Science and Technology, 44(21):8175-8181, doi:10.1021/es100884w 2010


    The objectives of this work were to compare enterococci (ENT) measurements based on the membrane filter, ENT(MF) with alternatives that can provide faster results including alternative enterococci methods (e.g., chromogenic substrate (CS), and quantitative polymerase chain reaction (qPCR)), and results from regression models based upon environmental parameters that can be measured in real-time. ENT(MF) were also compared to source tracking markers (Staphylococcus aureus, Bacteroidales human and dog markers, and Catellicoccus gull marker) in an effort to interpret the variability of the signal. Results showed that concentrations of enterococci based upon MF (p < 0.01). The correlations between MF and CS (r = 0.58, p < 0.01) were stronger than between MF and qPCR (r ≤ 0.36, p < 0.01). Enterococci levels by MF, CS, and qPCR methods were positively correlated with turbidity and tidal height. Enterococci by MF and CS were also inversely correlated with solar radiation but enterococci by qPCR was not. The regression model based on environmental variables provided fair qualitative predictions of enterococci by MF in real-time, for daily geometric mean levels, but not for individual samples. Overall, ENT(MF) was not significantly correlated with source tracking markers with the exception of samples collected during one storm event. The inability of the regression model to predict ENT(MF) levels for individual samples is likely due to the different sources of ENT impacting the beach at any given time, making it particularly difficult to to predict short-term variability of ENT(MF) for environmental parameters.

  16. Sinigalliano, C.D., J.M. Fleisher, M.L. Gidley, H.M. Solo-Gabriele, T. Shibata, L.R.W. Plano, S.M. Elmir, D. Wanless, J. Bartkowiak, R. Boiteau, K. Withum, A.M. Abdelzaher, G. He, C. Ortega, X. Zhu, M.E. Wright, J. Kish, J. Hollenbeck, T. Scott, L.C. Backer, and L.E. Fleming. Traditional and molecular analyses for fecal indicator bacteria in non-point source subtropical recreational marine waters. Water Research, 44(13):3763-3772, doi:10.1016/j.watres.2010.04.026 2010

    Abstract: The use of enterococci as the primary fecal indicator bacteria (FIB) for the determination of recreational water safety has been questioned, particularly in sub/tropical marine waters without known point sources of sewage. Alternative FIB (such as the Bacteroidales group) and alternative measurement methods (such as rapid molecular testing) have been proposed to supplement or replace current marine water quality testing methods which require culturing enterococci. Moreover, environmental parameters have also been proposed to supplement current monitoring programs. The objective of this study was to evaluate the health risks to humans from exposure to subtropical recreational marine waters with no known point source. The study reported symptoms between one set of human subjects randomly assigned to marine water exposure with intensive environmental monitoring compared with other subjects who did not have exposure. In addition, illness outcomes among the exposed bathers were compared to levels of traditional and alternative FIB (as measured by culture-based and molecular-based methods) and compared to easily measured environmental parameters. Results demonstrated an increase in self-reported gastrointestinal, respiratory and skin illnesses among bathers versus non-bathers. Among the bathers, a dose-response relationship by logistic regression modeling was observed for skin illness, where illness was positively related to enterococci enumeration by membrane filtration (odds ratio = 1.46 [95% confidence interval = 0.97-2.21] per increasing log10 unit of enterococci exposure) and positively related to 24 hour antecedent rain fall (1.04 [1.01-1.07] per increasing millimeters of rain). Acute febrile respiratory illness was inversely related to water temperature (0.74 [0.56-0.98] per increasing degree of water temperature). There were no significant dose response relationships between report of human illness and any of the other FIB or environmental measures. Therefore, for non-point source subtropical recreational marine waters, this study suggests that humans may be at increased risk of reported illness, and that the currently recommended and investigational FIB may not track gastrointestinal illness under these conditions; the relationship between other human illness and environmental measures is less clear.

  17. Elmir, S.M., T. Shibata, H.M. Solo-Gabriele, C.D. Sinigalliano, M.L. Gidley, G. Miller, L.R.W. Plano, J. Kish, K. Withum, and L.E. Fleming. Quantitative evaluation of enterococci and bacteroidales released by adults and toddlers in marine water. Water Research, 43(18):4610-4616, doi:10.1016/j.watres.2009.07.006 2009


    Traditionally, the use of enterococci has been recommended as the fecal indicator bacteria of choice for testing marine recreational water quality, and prior studies have shown that bathers shed large numbers of enterococci into the water. The current study expands upon prior research by evaluating shedding from both toddlers and adults, and by the expansion of measurements to include enterococci shedding via three different methods (membrane filter (MF), chromogenic substrate (CS), and quantitative polymerase chain reaction (qPCR)) and shedding of alternative fecal indicator bacteria (Bacteroidales human markers UCD and HF8 via qPCR). Two sets of experiments were conducted. The first experiment consisted of two groups of 10 adults who bathed together in a large pool. The second study consisted of 14 toddlers who bathed individually in a small pool which allowed for sand recovery. Sand recovery was used to estimate the amount of sand transported on the bodies of toddlers and to estimate the number of fecal indicator bacteria released from this sand. The numbers of estimated enterococci shed per adult ranged from 1.8 x 104 to 2.8 x 106 CFU, from 1.9 x 103 to 4.5 x 106 MPN, and from 3.8 x 105 to 5.5 x 106 GEU based on the MF, CS, and qPCR methods, respectively. The estimated numbers of Bacteroidales human markers ranged from 1.8 x 104 to 1.3 x 106 for UCD, and ranged from the below detection limit to 1.6 x 105 for HF8. The estimated amount of sand transported per toddler (n = 14) into the water column after sand exposure was 8 ± 6 g on average. When normalizing the numbers of enterococci shed from toddlers via sand by the 3.9 body surface area ratio, the differences between toddlers and adults were insignificant. Contributions of sands to the total enterococci (MF) shed per toddler was 3.7 ± 4.4% on average. Although shedding via beach sand may contribute a small fraction of the microbial load during initial bathing, it may have a significant role if bathers go to water repetitively after sand exposure.