Occurrence of Escherichia coli, noroviruses, and F-specific coliphages in fresh market-ready produce.
Forty samples of fresh produce collected from retail food establishments were examined to determine the occurrence of Escherichia coli, F-specific coliphages, and noroviruses. An additional six samples were collected from a restaurant undergoing investigation for a norovirus outbreak. Nineteen (48%) of the retail samples and all outbreak samples were preprocessed (cut, shredded, chopped, or peeled) at or before the point of purchase. Reverse transcription-PCR, with the use of primers JV 12 and JV 13, failed to detect norovirus RNA in any of the samples. All six outbreak samples and 13 (33%) retail samples were positive for F-specific coliphages (odds ratio undefined, P = 0.003). Processed retail samples appeared more likely to contain F-specific coliphages than unprocessed samples (odds ratio 3.8; 95% confidence interval 0.8 to 20.0). Only two (5.0%) retail samples were positive for E. coli; outbreak samples were not tested for E. coli. The results of this preliminary survey suggest that F-specific coliphages could be useful conservative indicators of fecal contamination of produce and its associated virological risks. Large-scale surveys should be conducted to confirm these findings.
Allwood
Paul B
PB
Division of Environmental and Occupational Health, School of Public Health, University of Minnesota, 420 Delaware Street S.E., Minneapolis, Minnesota 55455, USA.
Malik
Yashpal S
YS
Maherchandani
Sunil
S
Vought
Kevin
K
Johnson
Lee-Ann
LA
Braymen
Craig
C
Hedberg
Craig W
CW
Goyal
Sagar M
SM
D003090:Coliphages / Q000302:isolation & purification*; D003257:Consumer Product Safety; D004196:Disease Outbreaks; D004926:Escherichia coli / Q000302:isolation & purification*; D005243:Feces / Q000382:microbiology / Q000821:virology; D005506:Food Contamination / Q000032:analysis / Q000517:prevention & control; D005516:Food Microbiology; D006801:Humans; D029322:Norovirus / Q000302:isolation & purification*; D012367:RNA, Viral / Q000302:isolation & purification; D012147:Restaurants / Q000592:standards; D014675:Vegetables / Q000382:microbiology* / Q000821:virology
D012367:RNA, Viral