Microbial Contamination of Fresh Produce: What, Where, and How?

Abstract

Promotion of healthier lifestyles has led to an increase in consumption of fresh produce. Such foodstuffs may expose consumers to increased risk of foodborne disease, as often they are not subjected to processing steps to ensure effective removal or inactivation of pathogenic microorganisms before consumption. Consequently, reports of ready‐to‐eat fruit and vegetable related disease outbreak occurrences have increased substantially in recent years, and information regarding these events is often not readily available. Identifying the nature and source of microbial contamination of these foodstuffs is critical for developing appropriate mitigation measures to be implemented by food producers. This review aimed to identify the foodstuffs most susceptible to microbial contamination and the microorganisms responsible for disease outbreaks from information available in peer‐reviewed scientific publications. A total of 571 outbreaks were identified from 1980 to 2016, accounting for 72,855 infections and 173 deaths. Contaminated leafy green vegetables were responsible for 51.7% of reported outbreaks. Contaminated soft fruits caused 27.8% of infections. Pathogenic strains of Escherichia coli and Salmonella, norovirus, and hepatitis A accounted for the majority of cases. Large outbreaks resulted in particular biases such as the observation that contaminated sprouted plants caused 31.8% of deaths. Where known, contamination mainly occurred via contaminated seeds, water, and contaminated food handlers. There is a critical need for standardized datasets regarding all aspects of disease outbreaks, including how foodstuffs are contaminated with pathogenic microorganisms. Providing food business operators with this knowledge will allow them to implement better strategies to improve safety and quality of fresh produce.

Effect of Weather on the Die-Off of Escherichia coli and Attenuated Salmonella enterica Serovar Typhimurium on Preharvest Leafy Greens following Irrigation with Contaminated Water

“…Monitoring environmental conditions. The following weather conditions were recorded in all locations: temperature (°C), relative humidity (%), solar radiation (kW/m 2 . Hourly dew point was also calculated using the humidity.to.dewpoint function in the weathermetrics package (65).…”

“…As consumers increase consumption of fresh produce and as detection of illness cases and contaminated products improve, there has been an increase in the number of foodborne illnesses and recalls linked to produce ( 1 ). In particular, 51.7% ( n = 571) of produce-related outbreaks in developed countries have been linked to leafy greens ( 2 ). In the United States, there have been 6 multistate Escherichia coli O157:H7 outbreaks linked to leafy greens between 2017 and 2019, which have caused a total of 497 illnesses and 6 deaths ( 3 – 8 ).…”

Microbiological and Chemical Quality of Portuguese Lettuce—Results of a Case Study

“…"Fruits and vegetables are important components of a healthy diet", and their daily consumption reduces the risk of severe illnesses, such as cardiovascular diseases and certain types of cancer [1,2]. Despite these scientifically validated health benefits, contaminated produce (by virus, bacteria, or parasites) has been linked to major cases and outbreaks of foodborne diseases in recent years, and has led to some of the biggest food recalls [3,4]. Among the top 10 multistate outbreaks ranked by the number of illnesses in 2019 in the USA, six were linked to the consumption of raw produce [5].…”

“…Lettuce was included in the last dirty list of fruit and vegetables [ 9 ], and in the last EU report, it was one of the commodities that were found to contain multiples residues in more than 50% of the samples analyzed [ 10 ]. In addition, lettuce has been implicated in reported outbreaks of microbial foodborne diseases [ 4 ].…”

Lactic Acid Bacteria as Antibacterial Agents to Extend the Shelf Life of Fresh and Minimally Processed Fruits and Vegetables: Quality and Safety Aspects

“…In exception for their antimicrobial activity, LAB also have antifungal activity, which is of great interest, both against mycotoxigenic fungi and fungal mycotoxins, showing their potential by inactivation, removal, or detoxification processes [ 64 , 65 , 66 ]. The antifungal activity of LAB has prolonged the shelf life of fresh vegetables [ 67 ] and fruits [ 68 ].…”