Microbial Survey of Pennsylvania Surface Water Used for Irrigating Produce Crops.
Recent produce-associated foodborne illness outbreaks have been attributed to contaminated irrigation water. This study examined microbial levels in Pennsylvania surface waters used for irrigation, relationships between microbial indicator organisms and water physicochemical characteristics, and the potential use of indicators for predicting the presence of human pathogens. A total of 153 samples taken from surface water sources used for irrigation in southeastern Pennsylvania were collected from 39 farms over a 2-year period. Samples were analyzed for six microbial indicator organisms (aerobic plate count, Enterobacteriaceae, coliform, fecal coliforms, Escherichia coli, and enterococci), two human pathogens (Salmonella and E. coli O157), and seven physical and environmental characteristics (pH, conductivity, turbidity, air and water temperature, and sampling day and 3-day-accumulated precipitation levels). Indicator populations were highly variable and not predicted by water and environmental characteristics. Only five samples were confirmed positive for Salmonella, and no E. coli O157 was detected in any samples. Predictive relationships between microbial indicators and the occurrence of pathogens could therefore not be determined.
Department of Food Science, The Pennsylvania State University, University Park, Pennsylvania 16802, USA.
Audrey D
AD
Draper
Department of Food Science, The Pennsylvania State University, University Park, Pennsylvania 16802, USA.
Stephanie
S
Doores
Division of Science, The Pennsylvania State University-Berks Campus, Reading, Pennsylvania 19610, USA.
Hassan
H
Gourama
Department of Food Science, The Pennsylvania State University, University Park, Pennsylvania 16802, USA. lfl5@psu.edu.
Luke F
LF
LaBorde
D015169:Colony Count, Microbial; D004755:Enterobacteriaceae; D004926:Escherichia coli; D019453:Escherichia coli O157; D006801:Humans; D010414:Pennsylvania; D014867:Water; D014871:Water Microbiology
D014867:Water