Detection and risk assessment of diarrheagenic E. coli in recreational beaches of Brazil.
Marine beaches are important recreational and economic resources in Brazil, but the beaches' water quality is negatively impacted by the discharge of domestic sewage effluent. The occurrence of diarrheagenic Escherichiacoli among the E. coli isolated from three Brazilian marine beaches was investigated. Multiplex and single step PCR were used to screen 99 E. coli isolates for ten target toxin genes. Six toxin genes, stx1, eae, estp, esth, astA, and bfpA, were identified in 1% to 35% of the isolates. A quantitative microbial risk assessment (QMRA) of human exposure to diarrheagenic E. coli during marine recreation was carried out. The results indicated that the diarrheagenic E. coli risk is well below the U.S. EPA's recommended daily recreational risk benchmark. However, the overall recreational health risk due to all pathogens in the water could be much higher and exceeded the U.S. EPA's benchmark.
Biomedical Science Institute, Microbiology Department, University of São Paulo, Estado de São Paulo, SP 05508-000, Brazil; Department of Civil and Environmental Engineering, University of California, Irvine, CA 92697-2175, USA.
Vanessa F V
VFV
Rodrigues
Biomedical Science Institute, Microbiology Department, University of São Paulo, Estado de São Paulo, SP 05508-000, Brazil.
Irma N G
ING
Rivera
Department of Civil and Environmental Engineering, University of California, Irvine, CA 92697-2175, USA.
Keah-Ying
KY
Lim
Department of Civil and Environmental Engineering, University of California, Irvine, CA 92697-2175, USA. Electronic address: sjiang@uci.edu.
Sunny C
SC
Jiang
D001493:Bathing Beaches; D001938:Brazil; D004781:Environmental Exposure / Q000032:analysis; D004926:Escherichia coli / Q000235:genetics / Q000302:isolation & purification* / Q000472:pathogenicity*; D029968:Escherichia coli Proteins / Q000235:genetics; D036781:Fimbriae Proteins / Q000235:genetics; D006801:Humans; D060885:Multiplex Polymerase Chain Reaction; D011998:Recreation; D018570:Risk Assessment / Q000379:methods; D012722:Sewage; D022622:Shiga Toxin 1 / Q000235:genetics; D014481:United States; D014865:Waste Disposal, Fluid; D014871:Water Microbiology; D060753:Water Quality
C104901:BfpA protein, E coli; D029968:Escherichia coli Proteins; D012722:Sewage; D022622:Shiga Toxin 1; D036781:Fimbriae Proteins
Brazilian beaches; Diarrheagenic E. coli; Quantitative microbial risk assessment; Recreational health