title: Quantitation of Staphylococcus aureus in seawater using CHROMagar SA.
abstract: A microbiological algorithm has been developed to analyze beach water samples for the determination of viable colony forming units (CFU) of Staphylococcus aureus (S. aureus). Membrane filtration enumeration of S. aureus from recreational beach waters using the chromogenic media CHROMagar SA alone yields a positive predictive value (PPV) of 70%. Presumptive CHROMagar SA colonies were confirmed as S. aureus by 24-hour tube coagulase test. Combined, these two tests yield a PPV of 100%. This algorithm enables accurate quantitation of S. aureus in seawater in 72 hours and could support risk-prediction processes for recreational waters. A more rapid protocol, utilizing a 4-hour tube coagulase confirmatory test, enables a 48-hour turnaround time with a modest false negative rate of less than 10%.
authors.affiliation: Department of Medicine, John A. Burns School of Medicine, University of Hawai'i at Manoa, Honolulu, HI, USA. alantice@idlinks.com
authors.forename: Alan D
authors.initials: AD
authors.lastname: Tice
authors.forename: David
authors.initials: D
authors.lastname: Pombo
authors.forename: Jennifer
authors.initials: J
authors.lastname: Hui
authors.forename: Michelle
authors.initials: M
authors.lastname: Kurano
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Bankowski
authors.forename: Steven E
authors.initials: SE
authors.lastname: Seifried
mesh_terms: D000362:Agar; D015373:Bacterial Typing Techniques / Q000379:methods*; D015169:Colony Count, Microbial; D006801:Humans; D012623:Seawater / Q000382:microbiology*; D013211:Staphylococcus aureus / Q000302:isolation & purification*; D014871:Water Microbiology
chemical_list: D000362:Agar