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.

On October 19, 2011, FDA released a document1 which provides an overview of factors that potentially contributed to the contamination of fresh, whole cantaloupe with the pathogen Listeria monocytogenes which was implicated in a multi-state outbreak of listeriosis. In early September 2011, the Food and Drug Administration (FDA), in conjunction with the Centers for Disease Control and Prevention (CDC) and state health departments, began to investigate a multi-state outbreak of listeriosis. Early in the investigation, cantaloupes from Jensen Farms in the southeast region of Colorado were implicated in the outbreak.


On September 10, 2011, FDA, along with Colorado state officials, conducted an inspection at Jensen Farms and collected multiple samples, including whole cantaloupes and environmental (non-product) samples from within the facility, for laboratory analysis to identify the presence of Listeria monocytogenes. Of the 39 environmental swabs collected from within the facility, 13 were confirmed positive for Listeria monocytogenes with pulsed-field gel electrophoresis (PFGE) pattern combinations that were indistinguishable from three of the four outbreak strains collected from affected patients. Of the 13 positive environmental swabs, 12 were collected at the processing line and 1 was collected from the packing area. Cantaloupe collected from the firm’s cold storage during the inspection was also confirmed positive for Listeria monocytogenes with PFGE pattern combinations that were indistinguishable from two of the four outbreak strains.


FDA Environmental Swabs Positive Results


Processing Line


9 positive samples from the grading belt


Swabs 21, 22, 23, 24, 26, 27, 29, 30 & 33
2 positive samples from the conveyor


Swabs 20 & 28


1 positive sample from the felt rollers


Swab 13
Packing Area


1 positive sample from the conveyor belt


Swab 34


FDA Product Sample Results


1 Cantaloupe Sample collected from cold storage


5 subs tested positive


(10 whole cantaloupes or “Subs”)


Please refer to the section below for


FDA’s Sample Records and Results on Jensen Farms


As a result of the isolation of outbreak strains of Listeria monocytogenes in the environment of the packing facility and whole cantaloupes collected from cold storage, and the fact that this is the first documented listeriosis outbreak associated with fresh, whole cantaloupe in the United States, FDA initiated an environmental assessment in conjunction with Colorado state and local officials. FDA, state, and local officials conducted the environmental assessment at Jensen Farms on September 22-23, 2011. The environmental assessment was conducted to gather more information to assist FDA in identifying the factors that potentially contributed to the introduction, growth, or spread of the Listeria monocytogenes strains that contaminated the cantaloupe.


FDA identified the following factors as those that most likely contributed to the introduction, spread, and growth of Listeria monocytogenes in the cantaloupes:


Introduction:


There could have been low level sporadic Listeria monocytogenes in the field where the cantaloupe were grown, which could have been introduced into the packing facility.

A truck used to haul culled cantaloupe to a cattle operation was parked adjacent to the packing facility and could have introduced contamination into the facility.

Spread:
The packing facility’s design allowed water to pool on the floor near equipment and employee walkways.


The packing facility floor was constructed in a manner that made it difficult to clean the packing equipment was not easily cleaned and sanitized; washing and drying equipment used for cantaloupe packing was previously used for postharvest handling of another raw agricultural commodity


Growth:
There was no pre-cooling step to remove field heat from the cantaloupes before cold storage. As the cantaloupes cooled there may have been condensation that promoted the growth of Listeria monocytogenes


FDA’s findings regarding this particular outbreak highlight the importance for firms to employ good agricultural and management practices in their packing facilities as well as in growing fields. FDA recommends that firms employ good agricultural and management practices recommended for the growing, harvesting, washing, sorting, packing, storage and transporting of fruits and vegetables sold to consumers in an unprocessed or minimally processed raw form.


FDA has issued a warning letter2 to Jensen Farms based on environmental and cantaloupe samples collected during the inspection. FDA’s investigation at Jensen Farms is still considered an open investigation.

About 18% of the fish sampled didn't match the names on placards, labels and menus, according to a study by 'Consumer Reports'.

About 18% of the fish sampled didn't match the names on placards, labels and menus, according to a study by 'Consumer Reports'.


Consumer Reports Friday will reveal a mislabeled seafood scam that leaves millions of consumers clueless whether the fish they think they're buying is the fish they're actually getting.


The world's largest independent product-testing organization Friday will reveal that 22% of the seafood it tested at supermarkets, restaurants, fish markets, gourmet stores and big-box stores in three states was either mislabeled, incompletely labeled or misidentified by store or restaurant employees.


"Consumers are getting ripped off when they buy fish," says Kim Kleman, editor-in-chief of Consumer Reports.


This is no small matter. Americans spent $80.2 billion on seafood last year, up $5 billion from 2009. Mislabeling can be a serious health issue. Some consumers have allergies to specific types of fish, and pregnant women can end up eating fish they shouldn't — with high concentrations of mercury. Others trying to purchase more sustainable fish are being sold cheaper, unsustainable species.


The investigation, which took place in New York, New Jersey and Connecticut, included 190 pieces of fresh and frozen seafood that were DNA tested by two outside labs. The findings, in the December issue of Consumer Reports, do not speculate about the reasons for the fraud. Some mislabeling snafus:


•Only four of the 14 different types of fish purchased — Chilean sea bass, coho salmon and bluefin and ahi tuna — were always identified correctly.


•Not one of the 10 lemon soles tested was lemon sole — but more common and cheaper flounder. And of 22 red snapper samples, not one was definitively red snapper, though eight couldn't be ruled out.

•Some 18% of the samples didn't match the names on placards, labels or menus. Another 4% were incompletely labeled or misidentified.


Consumers Union, the public policy division of Consumer Reports, is calling for legislation and standardized seafood labeling.


Officials at the Food and Drug Administration, which oversees food labeling, say they're aware of the problem. "It's illegal to mislabel food," spokesman Doug Karas says. The agency recently supplied six labs with DNA-testing equipment for testing to begin in 2012, he says. But, he adds, "Primarily we look at food safety," not fraud.


But, Kleman says, "I don't think we should have to choose between safety and fraud."

Dear Dr. Donohue • Recently I heard that a number of people died from eating cantaloupe that had a bacterium called listeria. What causes it, and how did it originate? I have been growing vegetables all my life and never heard of it. Does it live just on the outside of fruits and vegetables, or does it get inside? Are there signs that listeria is on the ground or on foods? Does cooking kill it? — W.H.
Answer • Listeria is not a new bacterium. It's been around on this planet a lot longer than any of us current humans have been. It's found in soil, decaying vegetation, rivers, streams, lakes and in the digestive tracts of many animals and their feces. Many of us have been infected with it, but most often symptoms are so mild that they go unreported and untreated. Only on a relatively few occasions has listeria been a threat to life and health. The recent cantaloupe episode was one of those occasions.
This bacterium does not penetrate into the interior of fruits or vegetables. It's on the cantaloupe rind. Cutting the fruit with a knife permits bacteria to cling to the knife and be deposited inside the melon, on the edible part. All fruits and vegetables should be washed thoroughly before they're eaten.
Meats, chicken and seafood also can harbor listeria. They should all be well-cooked; cooking kills the germ. Unpasteurized milk is another food capable of transmitting it. It is not transferred from one human to another. An infected mother can pass the germ to her fetus.
People who are quite susceptible to infection with listeria are ones whose immune system is not as robust as it should be. Older individuals and newborns are at greater risk of becoming infected than are others. For people with healthy immune systems, the chief signs of infection are nausea, vomiting and diarrhea. Many never develop any signs. Heavy infections with great numbers of listeria cause a much more severe illness and can be fatal. Those examples actually are quite rare in comparison to the total number of infections.
You cannot tell if a food or if soil has listeria by sight alone.
Dear Dr. Donohue • On TV, I heard a doctor sing the importance of vitamin A. He also cautioned about the overuse of vitamin supplements. I don't know how valid studies on vitamins are, but they eventually become obsolete with the newest research. I will be 91 in a few months. — R.D.
Answer • I always pay attention to what 90-year-olds say. They must've done things right, or they wouldn't be here. I agree with you. Nutritional advice changes so rapidly and so radically that it is hard to evaluate it. I guess we have to judge what makes the best sense.

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.

The three prime targets of lawsuits in the cantaloupe listeria outbreak have just $17 million in liability coverage for more than 130 illness cases that could easily cost more than $100 million, say experts in liability law.
The Denver Post reports the wide gap could make new legal targets out of grocery stores, distributors and auditing labs as victims seek richer funds for compensation, according to product-law experts.
"If they can get the deep pockets in, they're going to get them in," said Denver lawyer Justin Prochnow.
"I think the case as a whole has the potential to make new law in Colorado," said lawyer Scott Eldredge, a malpractice and liability specialist who also teaches at the University of Denver's Sturm College of Law.
Seattle lawyer Bill Marler said a third-party auditor that certified Jensen's safety practices before the outbreak has also been threatened with lawsuits. PrimusLabs of California has $5 million in insurance.
Bob Stovicek, president of PrimusLabs, stands behind his company's audit as in line with cantaloupe-industry practices.
"Primus has never been sued, nor are we aware of any third-party auditing firms being sued under similar circumstances," Stovicek said in an e-mail. "That being said this is an almost unprecedented tragedy," adding that he is aware lawyers are trying to pull auditors into cases.
With deaths and serious illnesses often producing $1 million to $3 million each in bills and other compensation, the 139 cantaloupe illnesses will produce massive claims, attorneys say.
Attorneys' fees vary widely but generally are in the range of 15 percent to 30 percent of settlements.
In the listeria cases, attorneys may try to show retailers contributed by not demanding tougher farm audits, by failing to test for pathogens themselves, or by failing to wash the fruit one more time before sale.