title: Faecal indicator bacteria enumeration in beach sand: a comparison study of extraction methods in medium to coarse sands.
abstract: OBJECTIVE
  The absence of standardized methods for quantifying faecal indicator bacteria (FIB) in sand hinders comparison of results across studies. The purpose of the study was to compare methods for extraction of faecal bacteria from sands and recommend a standardized extraction technique.
  
  
  RESULTS
  Twenty-two methods of extracting enterococci and Escherichia coli from sand were evaluated, including multiple permutations of hand shaking, mechanical shaking, blending, sonication, number of rinses, settling time, eluant-to-sand ratio, eluant composition, prefiltration and type of decantation. Tests were performed on sands from California, Florida and Lake Michigan. Most extraction parameters did not significantly affect bacterial enumeration. anova revealed significant effects of eluant composition and blending; with both sodium metaphosphate buffer and blending producing reduced counts.
  
  
  CONCLUSIONS
  The simplest extraction method that produced the highest FIB recoveries consisted of 2 min of hand shaking in phosphate-buffered saline or deionized water, a 30-s settling time, one-rinse step and a 10 : 1 eluant volume to sand weight ratio. This result was consistent across the sand compositions tested in this study but could vary for other sand types.
  
  
  CONCLUSIONS
  Method standardization will improve the understanding of how sands affect surface water quality.
authors: Department of Civil & Environmental Engineering, Stanford University, Stanford, CA 94305, USA. aboehm@stanford.edu
authors: A B
authors: AB
authors: Boehm
authors: J
authors: J
authors: Griffith
authors: C
authors: C
authors: McGee
authors: T A
authors: TA
authors: Edge
authors: H M
authors: HM
authors: Solo-Gabriele
authors: R
authors: R
authors: Whitman
authors: Y
authors: Y
authors: Cao
authors: M
authors: M
authors: Getrich
authors: J A
authors: JA
authors: Jay
authors: D
authors: D
authors: Ferguson
authors: K D
authors: KD
authors: Goodwin
authors: C M
authors: CM
authors: Lee
authors: M
authors: M
authors: Madison
authors: S B
authors: SB
authors: Weisberg
mesh_terms: D001493:Bathing Beaches; D016983:Enterococcus / Q000302:isolation & purification*; D004926:Escherichia coli / Q000302:isolation & purification*; D019015:Geologic Sediments / Q000382:microbiology*; D010316:Particle Size; D012822:Silicon Dioxide
chemical_list: D012822:Silicon Dioxide