Microbiological quality and safety assessment of lettuce production in Brazil.
The microbiological quality and safety of lettuce during primary production in Brazil were determined by enumeration of hygiene indicators Escherichia coli, coliforms and enterococci and detection of enteric pathogens Salmonella and E. coli O157:H7 in organic fertilizers, soil, irrigation water, lettuce crops, harvest boxes and worker's hands taken from six different lettuce farms throughout the crop growth cycle. Generic E. coli was a suitable indicator for the presence of Salmonella and E. coli O157:H7, while coliforms and enterococci were not. Few pathogens were detected: 5 salmonellae and 2 E. coli O157:H7 from 260 samples, of which only one was lettuce and the others were manure, soil and water. Most (5/7) pathogens were isolated from the same farm and all were from organic production. Statistical analysis revealed the following environmental and agro-technical risk factors for increased microbial load and pathogen prevalence in lettuce production: high temperature, flooding of lettuce fields, application of contaminated organic fertilizer, irrigation with water of inferior quality and large distances between the field and toilets. Control of the composting process of organic fertilizers and the irrigation water quality appear most crucial to improve and/or maintain the microbiological quality and safety during the primary production of lettuce.
Ghent University, Faculty of Bioscience Engineering, Department of Food Safety and Food Quality, Laboratory of Food Microbiology and Food Preservation (LFMFP), Ghent, Belgium.
Siele
S
Ceuppens
Food Microbiology Laboratory of Food Science and Technology Institute (ICTA) of Federal University of Rio Grande do Sul (ICTA/UFRGS), Porto Alegre, Brazil.
Claudia Titze
CT
Hessel
Food Microbiology Laboratory of Food Science and Technology Institute (ICTA) of Federal University of Rio Grande do Sul (ICTA/UFRGS), Porto Alegre, Brazil.
Rochele
R
de Quadros Rodrigues
Food Microbiology Laboratory of Food Science and Technology Institute (ICTA) of Federal University of Rio Grande do Sul (ICTA/UFRGS), Porto Alegre, Brazil.
Sabrina
S
Bartz
Food Microbiology Laboratory of Food Science and Technology Institute (ICTA) of Federal University of Rio Grande do Sul (ICTA/UFRGS), Porto Alegre, Brazil.
Eduardo César
EC
Tondo
Ghent University, Faculty of Bioscience Engineering, Department of Food Safety and Food Quality, Laboratory of Food Microbiology and Food Preservation (LFMFP), Ghent, Belgium. Electronic address: mieke.uyttendaele@ugent.be.
Mieke
M
Uyttendaele
D000383:Agriculture / Q000592:standards*; D001938:Brazil; D004926:Escherichia coli / Q000302:isolation & purification / Q000502:physiology*; D019453:Escherichia coli O157 / Q000502:physiology; D055868:Floods; D005516:Food Microbiology; D064088:Hazard Analysis and Critical Control Points; D006358:Hot Temperature; D018545:Lactuca / Q000382:microbiology*; D015999:Multivariate Analysis; D018570:Risk Assessment; D012307:Risk Factors; D012475:Salmonella / Q000502:physiology
E. coli O157:H7; Faecal indicators; Irrigation water; Lettuce; Organic fertilizer; Salmonella