Fate of Escherichia coli O145 present naturally in bovine slurry applied to vegetables before harvest, after washing and simulated wholesale and retail distribution.
J Appl Microbiol
; 123(6): 1597-1606, 2017 Dec.
Article
in En
| MEDLINE
| ID: mdl-28948664
ABSTRACT
AIMS:
To determine the fate of Escherichia coli on vegetables that were processed through commercial wash treatments and stored under simulated retail conditions at 4°C or wholesale at fluctuating ambient temperatures (0-25°C, dependent on season). METHODS ANDRESULTS:
Bovine slurry that was naturally contaminated with E. coli O145 was applied without dilution or diluted 110 using borehole water to growing potatoes, leeks or carrots. Manure was applied 1 week prior to harvest to simulate a near-harvest contamination event by manure deposition or an application of contaminated water to simulate a flooding event or irrigation from a contaminated water source. At harvest, crops were contaminated at up to 2 log cfu g-1 . Washing transferred E. coli into the water of a flotation tank used for potato washing and did not completely remove all traces of contamination from the crop. Manure-contaminated potatoes were observed to contain 0·72 cfu E. coli O145 g-1 after processing and retail storage. Manure-contaminated leeks harboured 0·73-1·55 cfu E. coli O145 g-1 after washing and storage. There was no cross-contamination when leeks were spray washed. Washing in an abrasive drum resulted in less than perfect decontamination for manure-contaminated carrots. There were five post-distribution isolations from carrots irrigated with contaminated water 24 h prior to harvest.CONCLUSIONS:
Standard commercial washing and distribution conditions may be insufficient to reliably control human pathogenic E. coli on fresh produce. SIGNIFICANCE AND IMPACT Previous speculation that the cause of a UK foodborne disease outbreak was soil from imperfectly cleaned vegetables is plausible.Key words
Full text:
1
Database:
MEDLINE
Main subject:
Soil Microbiology
/
Vegetables
/
Escherichia coli O157
/
Food Microbiology
/
Manure
Type of study:
Evaluation_studies
Language:
En
Journal:
J Appl Microbiol
Year:
2017
Type:
Article
Affiliation country:
United kingdom