Listeria

See also: Study at London

• Es anaeróbica facultativa.
• Bacilo Gram positivo, pequeño, alargado y  que no forma esporas,
• Tolerante a sales,  criotolerante y su vez ácido- tolerante, entre otras características. 
• Posee una gran  resistencia a factores ambientales lo cual le permite estar ampliamente distribuida en la naturaleza,
• Se puede aislarse en suelo, agua, vegetación, animales 
  principalmente ganado bovino, porcino y ovino) además de aves silvestres, c
  rustáceos e insectos y se puede ser encontrada  frecuentemente en alimentos.
•  Crece en un amplio rango de temperaturas (de -7 °C a 45 °C).Así pues, carne, productos lácteos y productos frescos pueden ser contaminados por este patógeno.
• Puede originar bajo ciertas condiciones la enfermedad denominada Listeriosis. Brotes de listeriosis aparecen a partir de fuentes comunes tales como alimentos procesados listos para consumir, conservados durante largo tiempo en los refrigeradores.

Biological classification, or scientific classification in biology, is a method to group and categorize organisms by biological type, such as genus or species. Biological classification is part of scientific taxonomy.
Modern biological classification has its root in the work of Carolus Linnaeus, who grouped species according to shared physical characteristics. These groupings have since been revised to improve consistency with the Darwinian principle of common descent. Molecular phylogenetics, which uses DNA sequences as data, has driven many recent revisions and is likely to continue to do so. Biological classification belongs to the science of biological systematics.

Classification has been defined by Mayr as "The arrangement of entities in a hierarchical series of nested classes, in which similar or related classes at one hierarchical level are combined comprehensively into more inclusive classes at the next higher level." A class is defined as "a collection of similar entities", where the similarity consists of the entities having attributes or traits in common.

What makes biological classification different from other classification systems (e.g. classifying books in a library) is evolution: the similarity between organisms placed in the same taxon is not arbitrary, but is instead a result of shared descent from their nearest common ancestor. Accordingly, the important attributes or traits for biological classification are 'homologous', i.e., inherited from common ancestors. These must be separated from traits that are analogous. Thus birds and bats both have the power of flight, but this similarity is not used to classify them into a taxon (a "class"), because it is not inherited from a common ancestor. In spite of all the other differences between them, the fact that bats and whales both feed their young on milk is one of the features used to classify both of them as mammals, since it was inherited from a common ancestor(s).
Determining whether similarities are homologous or analogous can be difficult. Thus until recently, golden moles, found in South Africa, were placed in the same taxon (insectivores) as Northern Hemisphere moles, on the basis of morphological and behavioural similarities. However, molecular analysis has shown that they are not closely related, so that their similarities must be due to convergent evolution and not to shared descent, and so should not be used to place them in the same taxon.

A classification, as defined above, is necessarily hierarchical. In a biological classification, rank is the level (the relative position) in a hierarchy. (Rarely, the term "taxonomic category" is used instead of "rank".) There are seven main ranks defined by the international nomenclature codes: kingdom, phylum/division, class, order, family, genus, species. "Domain", a level above kingdom, has become popular in recent years, but has not been accepted into the codes.

The most basic rank is that of species, the next higher is genus, and then family. Ranks are somewhat arbitrary, but hope to encapsulate the diversity contained within a group — a rough measure of the number of diversifications that the group has been through.
The International Code of Zoological Nomenclature defines rank, in the nomenclatural sense, as:

The level, for nomenclatural purposes, of a taxon in a taxonomic hierarchy (e.g. all families are for nomenclatural purposes at the same rank, which lies between superfamily and subfamily). The ranks of the family group, the genus group, and the species group at which nominal taxa may be established are stated in Articles 10.3, 10.4, 35.1, 42.1 and 45.1.^[5]

There are slightly different ranks for zoology and for botany, including subdivisions such as tribe.

Source: http://en.wikipedia.org

Before Al Gore invented the Internet in 1994, there was this thing called paper, which was useful for keeping records.
Those with a fetish in the macabre or statistics may care that the listeria-in-cantaloupe outbreak, which has now killed 30 and sickened 139, pales in comparison to past outbreaks.
Robert Tauxe, deputy director of the U.S. Centers for Disease Control and Prevention’s Division of Foodborne, Waterborne and Environmental Diseases told Elizabeth Weise of USA Today the deadliest documented foodborne illness outbreak in the United States was in the winter of 1924-1925, when typhoid in raw oysters from New York City killed approximately 150 people and sickened more than 1,500.
The second largest outbreak linked to food occurred in Boston in 1911. Then, streptococcus in raw, unpasteurized milk killed 48 people and sickened more than 2,000. The disease was described as "septic sore throat' at the time, Tauxe says. Similar but smaller outbreaks like this one led to a national move to pasteurize milk in 1924 by the U.S. Public Health Service.
In 1922 in Portland, Ore., another outbreak of "septic sore throat" killed 22 people and sickened 487. That round of streptococcus was also linked to raw, unpasteurized milk.
And in 1919, an outbreak of botulism from olives put up in glass jars in California killed at least 15 people in three states. It resulted in a major change in how items were canned so that botulism would no longer be a problem.
But, Americans don’t want medical care like that practiced in 1919, nor should food production be rooted in some nostalgic past. Every death and illness from food is tragic, especially if preventable; what can be done to prevent this happening again? Telling consumers to wash cantaloupes in bleach is not a solution.

With recent fatalities, the Listeria outbreak that was linked to tainted cantaloupe still raises public concern. Understanding what Listeria is and recognizing the symptoms can help us become aware of what to look for.
Dr. David Golden, professor of food microbiology, explains how the public can take precautions against the deadly bacteria. "More specifically, the organism that caused this outbreak is Listeria monocytogenes," said Golden.
This is a pathogenic organism that is commonly found in animal intestines and throughout the environment, and causes illness in humans when consumed. The question has been raised on how an organism can make its way to host on fruit when it resides in unpasteurized milk and the inside of animal intestines.
Golden explains possible ways on how Listeria may have been transported. "It is not uncommon to find it [the organism] in the soil," said Golden. "If irrigation water is not properly treated, the spray can distribute those organisms."
In this case, another way of transport is from the harvesting of cantaloupes from the fields where the contaminants are packed in shipments, Golden explains.  If there is contamination in transfer, it can cross-contaminate whatever it touches.
Golden says direct contact with soil and other surfaces begins the contamination process. Basic precautions while cleaning produce, he says, can alleviate much of the potential risk of infection.
The organism can harbor in the fibrous rind of the cantaloupe although the rind is thick. The knife's blade can transport bacteria through the juice of the fruit. Not only is the knife a culprit, but using the same cutting board without washing is just as risky in spreading the deadly bacteria.
Golden says the range of immediate effects depends on the number of deadly organisms that are present on the cantaloupe. In some cases, Listeria takes time to show up in the human body.
Symptoms include diarrhea and, in severe cases, meningitis, which can result in death for a mother and her unborn baby. A high mortality rate to those who are infected is 20 to 30 percent.
Golden explains that food-borne illnesses are more common than what is known to the public. He says that often times, the only way we usually hear about an outbreak is when someone dies from its ill effects. A publicized outbreak such as this one heightens public awareness of the disease and is what makes this case so different; the high number in deaths from food poisoning.
On a positive note, Golden illustrates simple precautions that we can take to lessen the potential risk of infection. Washing the cantaloupe under running tap water dislodges organisms from the rind. Also dry with paper towels to prevent contaminants from lingering on dish towels.
"Rinse it, blot it and cut it," says Golden, referring to the steps of cleaning the cantaloupe. He also suggests avoiding the use of the same cutting board when cutting off the rind, or simply wash the cutting board before going to the next step after removing the rind.

But instead of adding extra effort to clean the cantaloupe, it may seem easier to eliminate the produce from our diet altogether.  However, this should not be the case.
"We should not avoid cantaloupe, but it's important to know where our food comes from," Golden says. "The risk of not eating healthy fruits and vegetables will far outweigh the risk of getting ill from eating produce with tainted organisms."

"The FDA will issue warnings when there is a potential outbreak," Golden explains referring to a Colorado farm's packing facility. "Tracking and tracing back to the one farm was identified early."
Since the farm was identified early, the cantaloupe was recalled quickly. "We may continue to see ill effects of the contamination maybe even up through Christmas because of the slow onset that may occur," said Golden.
The extent of sickness depends on a person's preexisting health condition if and when he or she comes in contact with the organisms.

On October 20, 2011, the FDA announced the recall of “Nike All-American” sandwiches, produced by Landshire, Inc. The FDA states that the sandwiches were sold at retail stores nationwide. Lynne Terry of the Oregonian reports that they were distributed by Walmart. The recalled product consisted of bologna, salami, ham and Swiss cheese and a bun. The FDA reports that the product tested positive for listeria.
Routine product sampling conducted by the North Carolina Department of Agriculture & Consumer Services on a sample of five sandwiches on Oct. 10 revealed the positive result.
To this point no illnesses have been reported. However, given that Listeria’s incubation period can stretch even beyond two months, we cannot be assured yet that no one will fall ill.

The frightening news about the outbreak of listeria tied to cantaloupe from Jensen Farms and Frontera Produce continues to pour forth.   The latest count has 133 ill and 28 dead with one miscarriage.
In light of this, some food-safety tips directly on point from Dr. David Golden, Ph.D. of Food Microbiology at University of Tennessee is welcome.   Some of the salient points from Dr. Golden:

"Rinse it, blot it and cut it," says Golden, referring to the steps of cleaning the cantaloupe. He also suggests avoiding the use of the same cutting board when cutting off the rind, or simply wash the cutting board before going to the next step after removing the rind.

Dr. Golden also re-iterated a point made here before - due to the long incubation period, the numbers of ill persons may continue to climb:  "We may continue to see ill effects of the contamination maybe even up through Christmas because of the slow onset that may occur."

The Listeria attorneys at Marler Clark, the nation’s foremost law firm dedicated to representing victims of foodborne illness and Dallas-based law firm Reyes Brown Reilley have filed a lawsuit on behalf of the family of a Dallas woman who died from a Listeria illness. This is the eighth lawsuit [1] filed by Marler Clark in a multi-state Listeria outbreak linked to Rocky Ford cantaloupe. The defendants in the lawsuit are Colorado-based cantaloupe producer Jensen Farms and Edinburg Texas-based distributor Frontera Produce.

At 139 sickened - with 29 deaths - the Jensen Farms Frontera Listeria Outbreak has moved into first place in the United States’ most deadly foodborne illness outbreaks.  The numbers of ill and dead are expected to increase in this recent Listeria Outbreak that has impacted 28 states.  Here are the top 2, not largest, but deadliest outbreaks in the U.S.:
1.  Jensen Farms Frontera Listeria Outbreak
•          September 2011 - ONGOING
•          Vehicle: whole cantaloupe
•          Number ill: 139
•          Deaths: 29 (30, county miscarriages)
2.  Jalisco's Listeria Outbreak
•          January 1985
•          Vehicle: cheese
•          Number ill: 142
•          Deaths: 28 (48, counting miscarriages)
As of November 1, 2011, a total of 139 persons infected with any of the four outbreak-associated strains of Listeria monocytogenes have been reported to CDC from 28 states.  The number of infected persons identified in each state is as follows: Alabama (1), Arkansas (1), California (2), Colorado (39), Idaho (2), Illinois (3), Indiana (3), Iowa (1), Kansas (10), Louisiana (2), Maryland (1), Missouri (6), Montana (1), Nebraska (6), Nevada (1), New Mexico (15), New York (2), North Dakota (2), Oklahoma (11), Oregon (1), Pennsylvania (1), South Dakota (1), Texas (18), Utah (1), Virginia (1), West Virginia (1), Wisconsin (2), and Wyoming (4). Twenty-nine deaths have been reported: Colorado (8), Indiana (1), Kansas (3), Louisiana (2), Maryland (1), Missouri (2), Nebraska (1), New Mexico (5), New York (2), Oklahoma (1), Texas (2), and Wyoming (1). Among persons who died, ages range from 48 to 96 years, with a median age of 81 years. In addition, one woman pregnant at the time of illness had a miscarriage.

The number of infected persons identified in each state is as follows:
Alabama (1), Arkansas (1), California (2), Colorado (39), Idaho (2), Illinois (3), Indiana (3), Iowa (1), Kansas (10), Louisiana (2), Maryland (1), Missouri (6), Montana (1), Nebraska (6), Nevada (1), New Mexico (15), New York (2), North Dakota (2), Oklahoma (11), Oregon (1), Pennsylvania (1), South Dakota (1), Texas (18), Utah (1), Virginia (1), West Virginia (1), Wisconsin (2), and Wyoming (4).

Twenty-nine deaths have been reported:
Colorado (8), Indiana (1), Kansas (3), Louisiana (2), Maryland (1), Missouri (2), Nebraska (1), New Mexico (5), New York (2), Oklahoma (1), Texas (2), and Wyoming (1).
Among persons who died, ages range from 48 to 96 years, with a median age of 81 years. In addition, one woman pregnant at the time of illness had a miscarriage.

Golden Glen Creamery of Bow, WA is voluntarily recalling Raw Cheddar because it has the potential to be contaminated with Listeria monocytogenes, an organism which can cause serious and sometimes fatal infections in young children, frail or elderly people, and others with weakened immune systems. Although healthy individuals may suffer only short-term symptoms such as high fever, severe headache, stiffness, nausea, abdominal pain and diarrhea, Listeria infection can cause miscarriages and stillbirths among pregnant women.
To date, no illnesses have been reported.
Approximately twenty (20) pounds of the Raw Cheddar was distributed through a very few, select retail stores in Washington State, as well as at Golden Glen’s on-farm store between September 22 and November 5 of this year. The packages range in size from ¼ to ½ pound pieces, and are random-weight cuts.
The product is vacuum packaged in clear plastic with a stick on label. The label reads in part: “Raw Cheddar,” “GOLDEN GLEN CREAMERY”and“Natural handcrafted cheese produced by the Jensen ladies.” The back of the product has a white sticker with the three-digit code “864.”
The Raw Cheddar is being voluntarily recalled by Golden Glen Creamery, and was a result of a surveillance sample collected and analyzed by the Washington State Department of Agriculture that was found to be positive for Listeria monocytogenes. The company has ceased the production and distribution of the product as FDA, the Washington State Department of Agriculture and the company continues their investigation as to what caused the problem.

The Canadian Food Inspection Agency (CFIA) is warning the public not to consume two Deschamps and Fromagerie Marie Kade brand cheese products because they may be contaminated with Listeria monocytogenes.
The Deschamps product is Queso Parrilla and the Fromagerie Marie Kade product is Halloom.
According the the CFIA, food contaminated with Listeria monocytogenes may not look or smell spoiled and consuming them may cause listeriosis, a foodborne illness.
"Listeriosis can cause high fever, severe headache, neck stiffness and nausea. Pregnant women, the elderly and people with weakened immune systems are particularly at risk," the agency said in a statement issued Friday night.
The cheese products have been distributed in Quebec and Ontario and are being recalled by the manufacturer. The CFIA says there have been no reported illnesses associated with eating the cheese.
For more information consumers can call the CFIA at 1-800-442-2342 / TTY 1-800-465-7735 (8 a.m. to 8 p.m. Eastern time, Monday to Friday)

The Canadian Food Inspection Agency says some Deschamps and Fromagerie Marie Kade brand cheese products may be contaminated with Listeria monocytogenes.

Eating local foods, at least as one focus of a daily diet, has turned from an esoteric experiment to just-shy-of-mainstream. As demand grows, for reasons of health, environment or the local economy, more producers have taken the time to grow or stock ingredients that were once unattainable

Meningitis (from Greek μῆνιγξ méninx, "membrane" and the medical suffix -itis, "inflammation") is an acute inflammation of the protective membranes covering the brain and spinal cord, known collectively as the meninges. The inflammation may be caused by infection with viruses, bacteria, or other microorganisms, and less commonly by certain drugs. Meningitis can be life-threatening because of the inflammation's proximity to the brain and spinal cord; therefore, the condition is classified as a medical emergency.

The most common symptoms of meningitis are headache and neck stiffness associated with fever, confusion or altered consciousness, vomiting, and an inability to tolerate light (photophobia) or loud noises (phonophobia). Children often exhibit only nonspecific symptoms, such as irritability and drowsiness. If a rash is present, it may indicate a particular cause of meningitis; for instance, meningitis caused by meningococcal bacteria may be accompanied by a characteristic rash.

A lumbar puncture diagnoses or excludes meningitis. A needle is inserted into the spinal canal to extract a sample of cerebrospinal fluid (CSF), that envelops the brain and spinal cord. The CSF is examined in a medical laboratory. The first treatment in acute meningitis consists of promptly administered antibiotics and sometimes antiviral drugs. Corticosteroids can also be used to prevent complications from excessive inflammation. Meningitis can lead to serious long-term consequences such as deafness, epilepsy, hydrocephalus and cognitive deficits, especially if not treated quickly. Some forms of meningitis (such as those associated with meningococci, Haemophilus influenzae type B, pneumococci or mumps virus infections) may be prevented by immunization. In 2013 meningitis resulted in 303,000 deaths – down from 464,000 deaths in 1990.

Sepsis (/ˈsɛpsɨs/, from Gr. σῆψις: the state of putrefaction or decay) is a potentially deadly medical condition that is characterized by a whole-body inflammatory state (called a systemic inflammatory response syndrome or SIRS) and the presence of a known or suspected infection. The body may develop this inflammatory response by the immune system to microbes in the blood, urine, lungs, skin, or other tissues. A lay term for sepsis is blood poisoning, also used to describe septicaemia. Severe sepsis is the systemic inflammatory response, plus infection, plus the presence of organ dysfunction.

Septicemia (also septicaemia or septicæmia [ˌsɛp.tə.ˈsi.miə] is a related medical term referring to the presence of pathogenic organisms in the bloodstream, leading to sepsis. The term has not been sharply defined. It has been inconsistently used in the past by medical professionals, for example as a synonym of bacteremia, causing some confusion.

Severe sepsis is usually treated in the intensive care unit with intravenous fluids and antibiotics. If fluid replacement isn't sufficient to maintain blood pressure, specific vasopressor medications can be used. Mechanical ventilation and dialysis may be needed to support the function of the lungs and kidneys, respectively. To guide therapy, a central venous catheter and an arterial catheter may be placed; measurement of other hemodynamic variables (such as cardiac output, or mixed venous oxygen saturation) may also be used. Sepsis patients require preventive measures for deep vein thrombosis, stress ulcers and pressure ulcers, unless other conditions prevent this. Some patients might benefit from tight control of blood sugar levels with insulin (targeting stress hyperglycemia), low-dose corticosteroids or activated drotrecogin alfa (recombinant protein C).

Listeriosis is an infectious but not contagious disease caused by the bacterium Listeria monocytogenes, far more common in domestics animals (domestic mammals and poultry), especially ruminants, than in human beings. It can also occur in feral animals—among others, game animals—as well as in poultry and other birds.

The causative bacterium lives in the soil and in poorly made silage and is acquired by ingestion. It is not contagious; over the course of 30-year observation period of sheep disease in Morocco, the disease only appeared in the late 2000s when feeding bag-ensiled corn became common.  Moreover, in Iceland, the disease is called "silage sickness".

The disease is usually sporadic, but can occur as farm outbreaks in ruminants.

Three main forms are usually recognized throughout the affected species:

    encephalitis, the most common form in ruminants
    late abortion
    gastro-intestinal septicemia with liver damage, in monogastric species as well as in preruminant calves and lambs

Listeriosis in animals can rarely be cured with antibiotics (tetracyclines, chloramphenicol) when diagnosed early, in goats, for example, by treating upon first noticing the disease's characteristic expression in the animal's face, but is generally fatal.

Listeria monocytogenes is the species of pathogenic bacteria that causes the infection listeriosis. It is a facultative anaerobic bacterium, capable of surviving in the presence or absence of oxygen.
 

L. monocytogenes is a Gram-positive, nonspore-forming, motile, facultatively anaerobic, rod-shaped bacterium. It is catalase-positive and oxidase-negative, and expresses a beta hemolysin, which causes destruction of red blood cells. This bacterium exhibits characteristic tumbling motility when viewed with light microscopy. Although L. monocytogenes is actively motile by means of peritrichous flagella at room temperature (20−25°C), the organism does not synthesize flagella at body temperatures (37°C).

The genus Listeria belongs to the class, Bacilli, and the order, Bacillales, which also includes Bacillus and Staphylococcus. The genus Listeria includes seven different species (L. monocytogenes, L. ivanovii, L. innocua, L. welshimeri, L. seeligeri, L. grayi, and L. murrayi). Both L. ivanovii and L. monocytogenes are pathogenic in mice, but only L. monocytogenes is consistently associated with human illness. There are 13 serotypes of L. monocytogenes that can cause disease, but more than 90 percent of human isolates belong to only three serotypes: 1/2a, 1/2b, and 4b. L. monocytogenes serotype 4b strains are responsible for 33 to 50 percent of sporadic human cases worldwide and for all major foodborne outbreaks in Europe and North America since the 1980s.

L. monocytogenes was first described by E.G.D. Murray in 1926 based on six cases of sudden death in young rabbits. Murray referred to the organism as Bacterium monocytogenes before J.H. Harvey Pirie changed the genus name to Listeria in 1940. Although clinical descriptions of L. monocytogenes infection in both animals and humans were published in the 1920s, not until 1952 in East Germany was it recognized as a significant cause of neonatal sepsis and meningitis. Listeriosis in adults would later be associated with patients living with compromised immune systems, such as individuals taking immunosuppressant drugs and corticosteroids for malignancies or organ transplants, and those with HIV infection.

Not until 1981, however, was L. monocytogenes identified as a cause of foodborne illness. An outbreak of listeriosis in Halifax, Nova Scotia involving 41 cases and 18 deaths, mostly in pregnant women and neonates, was epidemiologically linked to the consumption of coleslaw containing cabbage that had been treated with L. monocytogenes-contaminated raw sheep manure. Since then, a number of cases of foodborne listeriosis have been reported, and L. monocytogenes is now widely recognized as an important hazard in the food industry

Updated post

Listeria monocytogenes, a facultative anaerobe, intracellular bacterium, is the causative agent of listeriosis. It is one of the most virulent foodborne pathogens, with 20 to 30 percent of clinical infections resulting in death. Responsible for approximately 2,500 illnesses and 500 deaths in the United States (U.S.) annually, listeriosis is the leading cause of death among foodborne bacterial pathogens, with fatality rates exceeding even Salmonella and Clostridium botulinum.

L. monocytogenes is a Gram-positive bacterium, in the division Firmicutes, named for Joseph Lister. Motile via flagella at 30°C and below, but usually not at 37°C, L. monocytogenes can instead move within eukaryotic cells by explosive polymerization of actin filaments (known as comet tails or actin rockets).
Studies suggest up to 10% of human gastrointestinal tracts may be colonized by L. monocytogenes.
Nevertheless, clinical diseases due to L. monocytogenes are more frequently recognized by veterinarians, especially as meningoencephalitis in ruminants.

Due to its frequent pathogenicity, causing meningitis in newborns (acquired transvaginally), pregnant mothers are often advised not to eat soft cheeses such as Brie, Camembert, feta, and queso blanco fresco, which may be contaminated with and permit growth of L. monocytogenes. It is the third-most-common cause of meningitis in newborns.
More recently, L. monocytogenes has been used as the model organism to illustrate the pathobiotechnology concept.

Gram-positive bacteria are those that are stained dark blue or violet by Gram staining. This is in contrast to Gram-negative bacteria, which cannot retain the crystal violet stain, instead taking up the counterstain (safranin or fuchsine) and appearing red or pink. Gram-positive organisms are able to retain the crystal violet stain because of the high amount of peptidoglycan in the cell wall. Gram-positive cell walls typically lack the outer membrane found in Gram-negative bacteria.