Romaine lettuce | |
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Species | Lactuca sativa |
Romaine or cos lettuce (Lactuca sativa L. var. longifolia) is a variety of lettuce that grows in a tall head of sturdy dark green leaves with firm ribs down their centers. Unlike most lettuces, it is tolerant of heat. In North America, romaine is often sold as whole heads or as "hearts" that have had the outer leaves removed and are often packaged together.
Commercially sold romaine lettuce has occasionally been the subject of product warnings by both U.S. and Canadian health authorities warning that consumer supplies can become contaminated with or host pathogenic E. coli bacteria. Cattle can harbor the bacteria without ill effects and be asymptomatic carriers of the bacterium. Lettuce becomes contaminated with the bacterium as the result of cattle manure being used to fertilize crop fields, or the proximity of cattle pastures and feedlots to water sources used to irrigate crops. [1]
In North American English it is known as "romaine" lettuce, and in British English the names "cos" lettuce and "romaine" lettuce are both used. [2] Many dictionaries trace the word cos to the name of the Greek island of Cos, from which the lettuce was presumably introduced. [3] Other authorities trace cos to the Arabic word for lettuce, khusخس [xus] . [4] The first mention of cos lettuce in English dates from the late 17th century in John Evelyn's 1699 work Acetaria. A discourse of sallets. [5]
The lettuce apparently reached Western Europe via Rome, as it is called lattuga romana in Italian and laitue romaine in French, both meaning "Roman lettuce," hence the name "romaine", the common term in North America. [4]
For 3,000 years (from at least 2,700 BC), lettuce was associated with the ancient Egyptian god of fertility, Min, for its resemblance to the phallus. [6]
Romaine lettuce may be used in the Passover Seder ritual feast as a type of bitter herb. It symbolises the bitterness inflicted by the Egyptians while the Israelites were slaves in Egypt. [7] [8]
The day of 22 Germinal in the French Republican Calendar was dedicated to romaine lettuce, as "Romaine". [9]
Romaine is a common salad green and is the typical lettuce used in Caesar salad. Romaine lettuce is commonly used in Middle Eastern cuisine. Romaine, like other lettuces, may also be cooked. For example, it can be braised or made into soup. [10] [11] The thick ribs, especially on the older outer leaves, have a milky fluid that gives the romaine its typically bitter herb taste.
From November 2017 through January 2018, the Public Health Agency of Canada (PHA) identified romaine as being linked to illness in 41 persons in Canada. [12] A probably related outbreak affected 25 people in 15 states of the U.S. who ate leafy greens, but the U.S. Centers for Disease Control (CDC) were unable to confirm that it was romaine in particular. There was one death. The disease agent was Shiga toxin-producing E. coli O157:H7. The most recent illness started on December 12, 2017; the PHA declared the outbreak over on January 10, 2018, and the CDC declared it over on January 25. [13]
In response to another E. coli O157:H7 outbreak, which probably began in mid-March 2018, the CDC recommended in April 2018 that consumers not buy or eat romaine lettuce unless they could confirm it was not from the Yuma, Arizona, growing region. [14] [15] On May 22, 2018, after a month-long warning, the CDC announced it was now safe to consume romaine again. [16] The outbreak killed five people and caused 89 hospitalizations across 32 states. [17] [18] In June 2018, the Food and Drug Administration (FDA) traced the source of the latest E. coli outbreak to water from a canal located in Yuma, Arizona. [19]
In November 2018, the CDC and PHA issued a warning to consumers that romaine lettuce should not be consumed in any form, and that they should dispose of any currently on hand. The same strain of E. coli identified in the 2017-2018 outbreak was implicated. [20] [21] [22] At least 43 people became ill in this outbreak, which the FDA traced to one of six counties in central California: Monterey, San Benito, San Luis Obispo, Santa Barbara, Santa Cruz and Ventura. [23]
In North American supermarkets, romaine is widely available year-round. [10] Many US growers of romaine lettuce farm in Salinas, California, in the summer and the Imperial Valley and Yuma, Arizona, in the winter, relying on day laborers crossing the border from Mexico. [24] Much of the romaine lettuce sold in northern Europe is grown in southern Spain, relying on migrant laborers from Africa. [25]
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ignored (help)Cos lettuces are probably not named for the island of Kos but for the Arabic word for lettuce
Escherichia coli O157:H7 is a serotype of the bacterial species Escherichia coli and is one of the Shiga-like toxin–producing types of E. coli. It is a cause of disease, typically foodborne illness, through consumption of contaminated and raw food, including raw milk and undercooked ground beef. Infection with this type of pathogenic bacteria may lead to hemorrhagic diarrhea, and to kidney failure; these have been reported to cause the deaths of children younger than five years of age, of elderly patients, and of patients whose immune systems are otherwise compromised.
Lettuce is an annual plant of the family Asteraceae. It is most often grown as a leaf vegetable, but sometimes for its stem and seeds. Lettuce is most often used for salads, although it is also seen in other kinds of food, such as soups, sandwiches and wraps; it can also be grilled. One variety, celtuce, is grown for its stems, which are eaten either raw or cooked. In addition to its main use as a leafy green, it has also gathered religious and medicinal significance over centuries of human consumption. Europe and North America originally dominated the market for lettuce, but by the late 20th century the consumption of lettuce had spread throughout the world. As of 2021, world production of lettuce and chicory was 27 million tonnes, 53 percent of which came from China.
Foodborne illness is any illness resulting from the contamination of food by pathogenic bacteria, viruses, or parasites, as well as prions, and toxins such as aflatoxins in peanuts, poisonous mushrooms, and various species of beans that have not been boiled for at least 10 minutes.
Hemolytic–uremic syndrome (HUS) is a group of blood disorders characterized by low red blood cells, acute kidney injury, and low platelets. Initial symptoms typically include bloody diarrhea, fever, vomiting, and weakness. Kidney problems and low platelets then occur as the diarrhea progresses. Children are more commonly affected, but most children recover without permanent damage to their health, although some children may have serious and sometimes life-threatening complications. Adults, especially the elderly, may show a more complicated presentation. Complications may include neurological problems and heart failure.
Coliform bacteria are defined as either motile or non-motile Gram-negative non-spore forming bacilli that possess β-galactosidase to produce acids and gases under their optimal growth temperature of 35–37 °C. They can be aerobes or facultative aerobes, and are a commonly used indicator of low sanitary quality of foods, milk, and water. Coliforms can be found in the aquatic environment, in soil and on vegetation; they are universally present in large numbers in the feces of warm-blooded animals as they are known to inhabit the gastrointestinal system. While coliform bacteria are not normally the cause of serious illness, they are easy to culture, and their presence is used to infer that other pathogenic organisms of fecal origin may be present in a sample, or that said sample is not safe to consume. Such pathogens include disease-causing bacteria, viruses, or protozoa and many multicellular parasites. Every drinking water source must be tested for the presence of these total coliform bacteria.
The 2006 North American E. coli outbreak was an Escherichia coli O157:H7 outbreak from prepackaged spinach. The outbreak occurred in September 2006, and its origin was an Angus cattle ranch that had leased land to a spinach grower. At least 276 consumer illnesses and 3 deaths have been attributed as a result from the outbreak.
Escherichia coli O121 is a pathogenic serotype of Escherichia coli, associated with Shiga toxin, intestinal bleeding, and hemolytic-uremic syndrome (HUS). HUS, if left untreated, can lead to kidney failure.
Escherichia coli O104:H21 is a rare serotype of Escherichia coli, a species of bacteria that lives in the lower intestines of mammals. Although there are many serotypes of E. coli, when in animals, there are benefits or do not cause disease. Some serotypes of E. coli have been recognized as pathogenic to humans, e.g. E. coli O157:H7, E. coli O121 and E. coli O104:H21.
A novel strain of Escherichia coli O104:H4 bacteria caused a serious outbreak of foodborne illness focused in northern Germany in May through June 2011. The illness was characterized by bloody diarrhea, with a high frequency of serious complications, including hemolytic–uremic syndrome (HUS), a condition that requires urgent treatment. The outbreak was originally thought to have been caused by an enterohemorrhagic (EHEC) strain of E. coli, but it was later shown to have been caused by an enteroaggregative E. coli (EAEC) strain that had acquired the genes to produce Shiga toxins, present in organic fenugreek sprouts.
Escherichia coli O104:H4 is an enteroaggregative Escherichia coli strain of the bacterium Escherichia coli, and the cause of the 2011 Escherichia coli O104:H4 outbreak. The "O" in the serological classification identifies the cell wall lipopolysaccharide antigen, and the "H" identifies the flagella antigen.
Shigatoxigenic Escherichia coli (STEC) and verotoxigenic E. coli (VTEC) are strains of the bacterium Escherichia coli that produce Shiga toxin. Only a minority of the strains cause illness in humans. The ones that do are collectively known as enterohemorrhagic E. coli (EHEC) and are major causes of foodborne illness. When infecting the large intestine of humans, they often cause gastroenteritis, enterocolitis, and bloody diarrhea and sometimes cause a severe complication called hemolytic-uremic syndrome (HUS). Cattle are an important natural reservoir for EHEC because the colonised adult ruminants are asymptomatic. This is because they lack vascular expression of the target receptor for Shiga toxins. The group and its subgroups are known by various names. They are distinguished from other strains of intestinal pathogenic E. coli including enterotoxigenic E. coli (ETEC), enteropathogenic E. coli (EPEC), enteroinvasive E. coli (EIEC), enteroaggregative E. coli (EAEC), and diffusely adherent E. coli (DAEC).
Escherichia coli is a gram-negative, rod-shaped bacterium that is commonly found in the lower intestine of warm-blooded organisms (endotherms). Most E. coli strains are harmless, but pathogenic varieties cause serious food poisoning, septic shock, meningitis, or urinary tract infections in humans. Unlike normal flora E. coli, the pathogenic varieties produce toxins and other virulence factors that enable them to reside in parts of the body normally not inhabited by E. coli, and to damage host cells. These pathogenic traits are encoded by virulence genes carried only by the pathogens.
In 2006, there were several outbreaks of foodborne illness from spinach and lettuce contaminated by E. coli O157:H7.
The 1992–1993 Jack in the Box E. coli outbreak occurred when the Escherichia coli O157:H7 bacterium killed four children and infected 732 people across four US states. The outbreak involved 73 Jack in the Box restaurants in California, Idaho, Washington, and Nevada, and has been described as "far and away the most infamous food poison outbreak in contemporary history." The majority of the affected were under 10 years old. Four children died and 178 others were left with permanent injury including kidney and brain damage.
Driven by fresh-market use, the consumption of spinach has been on the rise in the United States. Per capita use of fresh-market spinach averaged 1 kilogram (2.2 lb) during 2004–2006, the highest since the mid-1940s. The fresh market now accounts for about three-fourths of all US spinach consumed. Much of the growth over the past decade has been due to sales of triple-washed, cello-packed spinach and, more recently, baby spinach. These packaged products have been one of the fastest-growing segments of the packaged salad industry.
The 2015 United States E. coli outbreak was an incident in the United States involving the spread of Escherichia coli O157:H7 through contaminated celery which was consumed in chicken salad at various large retailers. A product recall covering more than one dozen states and over 155,000 products has taken place as a result of the incident.
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