TABLE 3.
Summary of factors affecting persistence of various indicators and pathogens in beach sanda
| Reference | Organism type | Organism(s) | Observations | Spike source | Sand source | Analytical method |
|---|---|---|---|---|---|---|
| 106 | FIB | E. coli | Persisted over 40 days at 4, 10, or 20°C. | Environmental isolate | Wisconsin (Lake Winnebago) | Colisure |
| 103 | E. coli | Sand supports growth and provides a shield from UV radiation. | Laboratory-grown strain | Great Lakes (Bradford Beach, Lake Michigan) | Membrane filtration on mTEC | |
| 132 | E. coli, enterococci | Biotic interactions are important determinants of survival. | Environmental isolates | Florida (Hollywood Beach) | Membrane filtration on mTEC (E. coli) and mEI (enterococci) | |
| 133 | E. coli, enterococci | Moisture was a dominant factor for E. coli survival, but not for enterococci. | Laboratory-grown strains | California (Santa Monica Beach) | Membrane filtration on mTEC (E. coli) and mEI (enterococci) | |
| 131 | E. coli, enterococci | Protozoan predation and viral lysis are not important contributors to decay, but competition with indigenous bacterial populations is. | Laboratory-grown strains | Hawaii (Sand Island and Kailua Beach) | Membrane filtration on mTEC (E. coli) and mE-EIA (enterococci) | |
| 136 | C. perfringens | Greater survival in higher moisture content. | Laboratory-grown strain | Florida (Hollywood Beach) | Plating on mCP agar | |
| 134 | E. coli, enterococci, Enterococcus by qPCR | E. coli less persistent than enterococci. qPCR signal more persistent than for culturable enterococci. | Primary treated sewage | California (Lovers Points) | Membrane filtration on mTEC (E. coli) and mEI (enterococci) and by qPCR (Entero1a) | |
| 130 | E. coli, enterococci | Decay rates similar to those of bacterial pathogens. | Raw sewage | Great Lakes (Lake Superior, Duluth Boat Club Beach) | Membrane filtration on mTEC (E. coli) and mEI (enterococci) and by qPCR (Entero1a) | |
| Enterococcus by qPCR | Decay rates dissimilar to those of bacterial pathogens. | |||||
| 128 | Enterococci, Enterococcus by qPCR | Wetting of sand resulted in faster decay than with dry controls. | Seagull feces | California (Cowell Beach, Santa Cruz) | Membrane filtration on mEI (enterococci) and by qPCR (Entero1a) | |
| 135 | E. coli, enterococci, Enterococcus by qPCR, C. perfringens | C. perfringens persisted longer than E. coli and enterococci. | Raw sewage | Hawaii (Kualoa Beach) | Membrane filtration on mTEC (E. coli), mEI (enterococci) and mCP (C. perfringens), enterococci by qPCR (Entero1a). | |
| 110 | E. coli | Survival was greater in finer-grain sand and at lower temperatures. | Environmental isolate | Canada (Burlington and Marie Curtis Beaches) | Membrane filtration on mTEC | |
| 129 | E. coli, E. coli by qPCR | All FIB were detected for the duration of the experiment (∼2 mo). | Seagull feces, raw sewage | Great Lakes (Bradford Beach, Lake Michigan) | Membrane filtration on mTEC and by qPCR (uidA) | |
| Enterococci, Enterococcus by qPCR | Membrane filtration on mEI (enterococci) and by qPCR (Entero1a) | |||||
| 134 | Coliphage | Somatic, F+ | Somatic coliphage more persistent than F+. | Primary treated sewage | California (Lovers Points) | Double agar layer |
| 137 | Bacterial pathogens | E. coli O157:H7 | Grain size did not affect survival. | Environmental isolate | Great Britain (Porth Dafarch, Traeth Llydan, Porth Trecastell) | Plating on CT-SMAC agar |
| 136 | Staphylococcus aureus | Decay pattern similar to that of C. perfringens. | Environmental isolate | Florida (Hollywood Beach) | Plating on S110 agar and confirmation on MSA | |
| 134 | Salmonella spp. | Culturable pathogens more persistent than bacterial and viral indicators, but opposite was the case for the qPCR signal. | Primary treated sewage | California (Lovers Points) | Enrichment on TSB/Rappaport (MSRV) medium followed by streaking on XLD agar; confirmation on LIA/TSIA agar and by PCR (invA); also by qPCR (ttrA-ttrC) | |
| Campylobacter spp. | Enrichment in Bolton broth followed by streaking on modified Karmali agar and confirmation by PCR (16S rRNA); also by qPCR (16S rRNA) | |||||
| 130 | Campylobacter jejuni | Decayed more rapidly than FIB and MST markers. | Laboratory-grown strains | Great Lakes (Lake Superior, Duluth Boat Club Beach) | qPCR (16S rRNA) | |
| Methicillin-resistant S. aureus | Concns increased at 28% moisture. | qPCR (mecA) | ||||
| S. enterica serovar Typhimurium | Greater decay at lower moisture content (14%). | qPCR (ttrRSBCA) | ||||
| Shigella flexneri | qPCR (ipaH) | |||||
| 134 | MST markers | Human associated (HF183) | Persistence similar to that of Entero1a. | Primary treated sewage | California (Lovers Points) | qPCR |
| 130 | General (AllBac) | Concns increased at 28% moisture. | Raw sewage | Great Lakes (Lake Superior, Duluth Boat Club Beach) | qPCR | |
| Human associated (HF183) | Decay rates similar to those of bacterial pathogens. | |||||
| 128 | Seagull associated (Cat) | Greater decay than enterococci in dry sands, but similar decay in wetted sands. | Seagull feces | California (Cowell Beach, Santa Cruz) | qPCR | |
| 129 | Human associated (Lachno2, BacHum), seagull associated (Gull2) | All MST markers decayed more rapidly than FIB (culture or qPCR). | Seagull feces, raw sewage | Great Lakes (Bradford Beach, Lake Michigan) | qPCR | |
| 138 | Seagull associated (Gull2) | Remained detectable for the duration of the study (28 days). | Laboratory-grown strain | Florida (Inner Cabrillo Beach) | qPCR |
a
TSB, tryptic soy broth; XLD, xylose lysine deoxycholate; LIA, lysine iron agar; TSIA, triple-sugar iron agar; mTEC, membrane thermotolerant E. coli; mEI, membrane Enterococcus indoxyl-β-d-glucoside agar; mE-EIA, membrane Enterococcus esculin iron agar; mCP, membrane Clostridium perfringens; CT-SMAC agar, cefixime-tellurite-sorbitol MacConkey agar; S110 agar, Staphylococcus agar no. 110; MSA, mannitol salt agar.