Vegas Luxor guest dies of Legionnaires

Published: Jan. 31, 2012 at 4:35 PM

LAS VEGAS, Jan. 31 (UPI) -- A guest who stayed at the Luxor Hotel and Casino in Las Vegas in December and contracted Legionnaires' disease has died, Nevada health officials said.

Brian Labus, a senior epidemiologist at the Southern Nevada Health District, said the Centers for Disease Control and Prevention has not released the patient's name or when he or she died, the Las Vegas Sun reported Tuesday.

Health officials found Luxor water samples tested positive for Legionlla bacteria.

Gordon Absher, vice president of public affairs for MGM Resorts International, said super-heating and super-chlorinating water was used to kill the bacteria in the area where the deceased guest stayed, within a day the test results were confirmed, Absher said.

Within 10 days the hotel will undertake a voluntary remediation for the rest of the hotel, Absher said.

"We take this very seriously," Absher told the Sun said. "Health of our guests and our employees is of paramount importance to MGM Resorts."

The Luxor also developed a monitoring plan to prevent this from occurring, Labus said.

Last spring, two guests staying at the Luxor also became ill with Legionnaires' disease, but both recovered.

At the time, the health district collected bulk water samples for an environmental assessment, but no Legionella bacteria were detected, officials said.

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Application of Legionella pneumophila-specific quantitative real-time PCR combined with direct amplification and sequence-based typing in the diagnosis and epidemiological investigation of Legionnaires’ disease

Immunosuppressants/tumour necrosis factor inhibitors: Legionnaires' disease: 24 case reports

Keywords: Adalimumab, adverse reactions - serious; Azathioprine, adverse reactions - serious; Elderly; Etanercept, adverse reactions - serious; Hydroxychloroquine, adverse reactions - serious; Infliximab, adverse reactions - serious; Leflunomide, adverse reactions - serious; Legionnaires'-disease, drug-induced; Mercaptopurine, adverse reactions - serious; Methotrexate, adverse reactions - serious; Methylprednisolone, adverse reactions - serious; Prednisone, adverse reactions - serious

Document Type: Short communication

Publication date: 2012-01-01

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Outbreak of Legionnaires' Disease Traced to Hospital Fountain

WEDNESDAY, Jan. 11 (HealthDay News) -- A decorative fountain in a hospital lobby was the cause of a 2010 Legionnaires' disease outbreak in Wisconsin, a new study says.

Legionnaires' disease is a severe and potentially deadly form of pneumonia caused by the bacteria Legionella, which can be inhaled from contaminated water sources.

State and local health officials launched an investigation after eight people in southeast Wisconsin developed Legionnaires' disease. After interviewing the patients, investigators identified one hospital as the origin of the outbreak.

Environmental testing within the hospital found notable amounts of Legionella in samples collected from the "water wall" decorative fountain in the hospital's main lobby. All eight patients had spent time in the lobby, the study said.

The fountain was shut down when it was first suspected as a source of the outbreak and hospital officials alerted staff and about 4,000 potentially exposed patients and visitors. All eight patients recovered and no further cases of Legionnaires' disease occurred after the fountain was shut down.

Before the outbreak, the fountain had undergone routine cleaning and maintenance, the researchers said.

"Since our investigation, the Wisconsin Division of Public Health has developed interim guidelines advising health-care facilities with decorative fountains to establish strict maintenance procedures and conduct periodic bacteriologic monitoring for Legionella," study lead author Thomas Haupt, an epidemiologist with the Wisconsin Division of Public Health, said in a journal news release.

"The guidelines stress that until additional data are available that demonstrate effective maintenance procedures for eliminating the risk of Legionella transmission from indoor decorative water fountains in health-care settings, water fountains of any type should be considered at risk of becoming contaminated with Legionella bacteria," he added.

The study appears in the February issue of the journal Infection Control and Hospital Epidemiology.

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Contaminated Dental Surgery Equipment Source of Legionnaire's Disease Death

Editor's Choice
Academic Journal
Main Category: Dentistry
Also Included In: Infectious Diseases / Bacteria / Viruses
Article Date: 17 Feb 2012 - 5:00 PST

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This week's issue of The Lancet describes a case report of an 82-year-old woman in Italy who died of Legionnaires disease after becoming infected with L pneumophila at her dentist. This case has prompted the authors - led by Dr Maria Luisa Ricci at the Istituto Superiore di Sanita, Rome, Italy, to call for various control measures at dental surgeries to prevent similar incidents.

Suffering with fever and respiratory distress, the woman who was conscious and responsive and had no underlying disease, was admitted in February, 2011, to the intensive care unit of the "G.B. Morgagni-Pierantoni" Hospital, Department of emergency Anaesthesia and Intensive Care Unit, Forlì, Italy.

Results from a chest radiography showed multiple areas of lung consolidation. A Legionella pneumophila urinary antigen test quickly diagnosed the woman with Legionnaires' disease and she was immediately given oral antibiotics (ciprofloxacin) every 12 hours. However, she sadly died two days later after developing rapid and irreversible septic shock, prompting an investigation to find the source of L pneumophila.

The patient had been at home for the majority of the time during the 2 to 10 day incubation period, leaving only twice to attend dentist appointments.

The investigators took water samples from the dental practice's tap, the tap and the high-speed turbine of the dental unit waterlines, as well as from the woman's home (shower and taps) in order to investigate possible L pneumophila contamination. They found that samples from her home tested negative for L pneumophila, but samples from the dental practice tested positive. After laboratory experiments were conducted, results showed genomic matching between L pneumphila in the dental unit waterline and in the women's respiratory secretion.

L pneumophila is a Gram-negative bacterium found in man-made water systems and is ubiquitous in natural water environments. The bacteria can infect individuals by inhalation or microaspiration of aerosolized water causing Pontiac fever (a flu-like disease) or Legionnaires' disease (severe pneumonia), mostly affecting immune-compromised patients and the elderly.

Spas, fountains, air-conditioning systems, and hot-water systems, have been demonstrated to be leading sources of infection.

It has been widely documented that dental waterlines are substantially contaminated with Legionella and studies have also demonstrated that the blood of dentists and dental practice staff has a higher prevalence of antibodies to L pneumophila, which indicates that people working in a dental practice environment are potentially at risk. However, prior to this case, the researchers knew no other cases in which Legionnaires' disease had been linked to this source of infection.

The authors explain:

"The case here shows that the disease can be acquired from a dental unit waterline during routine dental treatment. Aerosolized water from high-speed turbine instruments was most likely the source of the infection. Legionella contamination in dental unit waterlines must be minimized to prevent exposure of patients and staff to the bacterium.

We suggest several control measures: use of anti-stagnation and continuous-circulation water systems; use of sterile water instead of the main water supply in the dental unit waterline; application of discontinuous or continuous disinfecting treatment; daily flushing of all outlets and before each dental treatment; use of filters upstream of the instruments; and annual monitoring of the waterline. Further useful procedures to prevent legionellosis within dental surgeries can be obtained from [already available] dedicated guidelines."

Written by Grace Rattue
Copyright: Medical News Today
Not to be reproduced without permission of Medical News Today

Visit our dentistry section for the latest news on this subject. “Pneumonia associated with a dental unit waterline” Maria Luisa Ricci et al.
The Lancet, Volume 379, Issue 9816, Page 684, 18 February 2012, doi:10.1016/S0140-6736(12)60074-9 Please use one of the following formats to cite this article in your essay, paper or report:

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22 Feb. 2012. APA

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Las Vegas' Luxor guests had Legionnaires': officials

Home : Health : Las Vegas' Luxor guests had Legionnaires': officials

SLIDES.showHideViewT();The Associated Press

Date: Tuesday Jan. 31, 2012 9:25 AM ET

LAS VEGAS — Health officials in Las Vegas said Monday that the bacteria that causes Legionnaires' disease was found in water samples at the Luxor hotel-casino this month after a guest died of the form of pneumonia.

The Southern Nevada Health District said the Centers for Disease Control and Prevention national surveillance program reported three cases in the past year of Luxor guests being diagnosed with the disease caused by Legionella bacteria.

The Las Vegas Strip resort's water was tested after the first two cases were reported during the spring of last year, but no Legionella bacteria was detected, district officials said. Those guests recovered.

Officials say the Luxor, owned by MGM Resorts International, immediately began a remediation process once the bacteria was found.

MGM Resorts spokesman Gordon Absher said treatment procedures include superheating and super-chlorination of the water system.

"We are confident in the integrity of our systems and the safety protocols we follow at all our hotels. Guest and employee safety is always a top priority at our company," Absher said. "Even before last summer, MGM Resorts led the industry with aggressive and stringent programs to control Legionella issues common to all large buildings."

Absher said the company's resorts regularly test for Legionella and treat water systems preventatively, before bacteria are detected.

The new cases come as the company is already facing a civil lawsuit from guests who said they were infected with Legionella at the Aria Resort & Casino, part of the CityCenter complex that is half-owned by MGM Resorts.

MGM Resorts notified guests that they might have been exposed to the bacteria between June 21 and July 4 after the district reported six cases of Legionnaires' disease in July. The district said those guests recovered after treatment.

Eight guests sued in August, seeking $337.5 million in damages from the resort and its builders. An MGM Resorts spokesman at the time denied negligence, saying hotel officials carefully communicated with its guests and reimbursed them fairly for legitimate medical expenses. The case is still pending in federal court in Las Vegas.

Most people who are exposed to the bacteria don't get sick, according to the CDC. Smokers, people over age 50 and those who have chronic lung disease or weak immune systems are most susceptible, the CDC said.

The bacteria isn't spread between people. It grows most often in warm water, infecting people when they breathe in mist or vapor that has been contaminated.

The disease takes its name from an outbreak at the Pennsylvania American Legion convention held at the Bellevue-Stratford Hotel in Philadelphia in 1976.

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Health board fined after patient contracts Legionnaires'

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Study Links Hospital Water Wall, Legionnaires' Disease

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An Outbreak of Legionnaires Disease Associated with a Decorative Water Wall Fountain in a Hospital

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3rd Briton dies of Legionnaires' disease in Spanish hotel

Home : Health : 3rd Briton dies of Legionnaires' disease in Spanish hotel

SLIDES.showHideViewT();The Associated Press

Date: Friday Feb. 3, 2012 6:22 AM ET

MADRID, Spain — Spanish health officials say a third British national has died from Legionnaires' disease while vacationing in Spain.

A Valencia regional government statement Friday said the three, aged between 73 and 78, had contracted the disease at a hotel in the eastern town of Calpe.

The Valencia statement said a further 10 Britons and four Spaniards are being treated for the disease.

The U.K.-based company Saga Holidays reported the first two deaths Thursday, saying the Britons had stayed at the Diamante Beach Hotel in Calpe.

The names of the three victims were not released.

The regional government said authorities have taken measures to control the outbreak, including closing the hotel.

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Legionnaires' Disease

Legionellosis is an infection that is caused by a bacterium.The bacterium thrives in the mist that is sprayed from air-conditioning ducts.The bacterium can infest an entire building.The illness takes two distinct forms: Legionnaires' disease and Pontiac fever.Legionnaires' disease is the more severe form and can be fatal.Pontiac fever is the far milder form of the illness.Symptoms of Legionnaires' disease include fever, chills, and a cough.At its worst, Legionnaires' disease can cause severe pneumonia and respiratory failure.Although antibiotics are effective for treatment, the most useful approach is prevention.

Legionellosis is an infection that is caused by the bacterium Legionella pneumophila. The disease has two distinct forms:

Pneumonia Pneumonia is inflammation of one or both lungs with consolidation. Pneumonia is frequently but not always due to infection. The infection may be bacterial, viral, fungal or parasitic. Symptoms may include fever, chills, cough with sputum production, chest pain, and shortness of breath.Diarrhea Diarrhea is a change is the frequency and looseness of bowel movements. Cramping, abdominal pain, and the sensation of rectal urgency are all symptoms of diarrhea. Absorbents and anti-motility medications are used to treat diarrhea.Headache Headaches can be divided into two categories: primary headaches and secondary headaches. Migraine headaches, tension headaches, and cluster headaches are considered primary headaches. Secondary headaches are caused by disease. Headache symptoms vary with the headache type. Over-the-counter pain relievers provide short-term relief for most headaches.Chronic Cough Chronic cough is a cough that does not go away and is generally a symptom of another disorder such as asthma, allergic rhinitis, sinus infection, cigarette smoking, GERD, postnasal drip, bronchitis, pneumonia, medications, and less frequently tumors or other lung disease. Treatment of chronic cough is dependant upon the cause.Fever Although a fever technically is any body temperature above the normal of 98.6 degrees F. (37 degrees C.), in practice a person is usually not considered to have a significant fever until the temperature is above 100.4 degrees F (38 degrees C.). Fever is part of the body's own disease-fighting arsenal: rising body temperatures apparently are capable of killing off many disease- producing organisms.ARDS (Acute Respiratory Distress Syndrome) Acute respiratory distress syndrome (ARDS) is a lung condition in which trauma to the lungs leads to inflammation of the lungs, accumulation of fluid in the alveolar air sacs, low blood oxygen, and respiratory distress. Causes of ARDS include: pneumonia, aspiration, severe blow to the chest, sepsis, severe injury with shock, drug overdose, and/or inflamed pancreas. Treatment for ARDS include extra oxygen, and/or medication.




Chronic Cough »

Chronic cough is a cough that persists. Chronic cough is not a disease in itself; rather it is a symptom of an underlying condition. Chronic cough is a common problem and the reason for many doctor visits.

Some common causes of chronic cough include asthma, allergic rhinitis, sinus problems (for example sinus infection), and esophageal reflux of stomach contents. In rare occasions, chronic cough may be the result of aspiration of foreign objects into the lungs (usually in children). It is very important to see a doctor who may order a chest X-ray if a chronic cough is present. The following are common causes of chronic coughing.

Cigarette smoking actually is the most common cause of chronic cough. Asthma is a disease of airways, resulting in difficulty breathing or wheezing often characterized by abnormal breathing...

Read the Chronic Cough article »

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Cluster of travel-associated Legionnaires' disease in Lazise, Italy, July to August 2011

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How Legionnaires' bacteria proliferate, cause disease

ScienceDaily (Nov. 17, 2011) — A University of Louisville scientist has determined for the first time how the bacterium that causes Legionnaires' disease manipulates our cells to generate the amino acids it needs to grow and cause infection and inflammation in the lungs.

The results are published online on Nov. 17 in Science.

Yousef Abu Kwaik, Ph.D., the Bumgardner Endowed Professor in Molecular Pathogenesis of Microbial Infections at UofL, and his team believe their work could help lead to development of new antibiotics and vaccines.

"It is possible that the process we have identified presents a great target for new research in antibiotic and vaccine candidates, not only for Legionnaires' disease but in other bacteria that cause illness," he said.

According to the Centers for Disease Control and Prevention, Legionnaires' disease is a lung infection caused by the bacterium called Legionella. The bacterium got its name in 1976, when many people who went to a Philadelphia convention of the American Legion suffered from an outbreak of pneumonia of unknown causes that was later determined to be caused by the bacterium. Each year, between 8,000 and 18,000 people are hospitalized with Legionnaires' disease in the U.S. There is no vaccine currently available for it.

For two years, the researchers examined Legionella which is an intracellular bacterium that exists in amoebae in the water systems; it is transmitted to humans through inhalation of water droplets. Cooling towers and whirlpools are the major sources of transmission. The bacterium uses the amoeba's cellular process to "tag" proteins, causing them to degrade into their basic elements of amino acids. These amino acids are used by the bacteria as the main source of energy to grow and cause disease.

"The bacteria live on an 'Atkins diet' of low carbs and high protein, and they trick the host cell to provide that specialized diet," Abu Kwaik said.

The same process occurs in a host -- animal or human -- who inhales the bacterium and is diagnosed with Legionnaires' disease. However, the bacteria do not tag the proteins, but rather trick the host into tagging the proteins for degradation to generate the amino acids.

In the laboratory, Abu Kwaik and his team saw that by inactivating the bacterial virulence factor responsible for tricking the cell into tagging proteins for degradation in mice models, the pulmonary disease was totally prevented. This was totally due to disabling the bacteria from generating amino acids, he said.

The process was then reversed, and the disease became evident when the mice, infected by the disabled bacteria, were injected with amino acids to compensate for the inability of the altered bacteria.

"Bacteria need to live on high protein and amino acids as sources of nutrition and energy in order to replicate in a host. This is what causes pulmonary disease," Abu Kwaik said. "No one has known how they generate sufficient sources of nutrients from the host to proliferate. Our work is the first to identify this process for any bacteria that cause disease."

He added that the type of host infected does not appear to affect the process. "Whether in a single-cell amoeba or a multi-cellular mammal, Legionella seems to know what to do; the process is the same, and is highly conserved through evolution. By interfering with the bacterium's sources of nutrients, we can stop it from thriving and causing disease."

Examining nutrient sources for organisms with the goal of stopping them from acquiring nutrients is a relatively new arena of basic research that deserves further study, he said. "We went after the basics -- the food and energy source -- which are prerequisite for the bacteria to grow and cause disease. It is not a process that is well understood yet, but by first discovering how an organism gets nutrients by tricking the host into degrading proteins, and then interfering with that process, we can, in effect, starve it to death and prevent or treat the disease."

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Journal Reference:

Christopher T. D. Price, Tasneem Al-Quadan, Marina Santic, Ilan Rosenshine, and Yousef Abu Kwaik. Host Proteasomal Degradation Generates Amino Acids Essential for Intracellular Bacterial Growth. Science, 17 November 2011 DOI: 10.1126/science.1212868

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Update on Legionnaires' cluster in UK travellers returning from Corfu

The Health Protection Agency (HPA) has issued an update on the Legionnaire’s cluster – three further cases have now been confirmed, which brings the total to 12 confirmed cases in people who have travelled to Corfu since August.  Another three possible cases with travel history to Corfu are currently under investigation.

Laboratory tests have identified three different subtypes of Legionnella from the patients’ samples, suggesting that one common source is unlikely. In addition, detailed questioning of the people who became unwell has also failed to reveal a common source.

The HPA is continuing to advise people going on holiday to Corfu to be aware of the signs and symptoms of Legionnaires’ disease – please see the link below for details.  A briefing note was recently issued to GPs asking them to be alert to returning travellers from Corfu with relevant symptoms. 

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How Legionnaires' bacteria cause disease

Published: Nov. 18, 2011 at 11:05 PM

LOUISVILLE, Ky., Nov. 18 (UPI) -- A bacterium that causes Legionnaires' disease manipulates cells to generate amino acids it needs to grow and infect the lungs, U.S. researchers say.

Yousef Abu Kwaik of the University of Louisville and his team said their work could help lead to development of new antibiotics and vaccines for the disease.

"It is possible that the process we have identified presents a great target for new research in antibiotic and vaccine candidates, not only for Legionnaires' disease but in other bacteria that cause illness," Abu Kwaik said in a statement.

For two years, the researchers examined Legionella, which is an intercellular bacterium that exists in amoebae in the water systems; it is transmitted to humans through inhalation of water droplets. Cooling towers and whirlpools are the major sources of transmission.

The study, published in the journal Science, said the bacterium uses the amoeba's cellular process to "tag" proteins, causing them to degrade into their basic elements of amino acids, which are used by the bacteria as the main source of energy to grow and cause disease.

"The bacteria live on an 'Atkins diet' of low carbs and high protein and they trick the host cell to provide that specialized diet," Abu Kwaik said.

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UofL researcher determines how Legionnaires' bacteria proliferate, cause disease

Public release date: 17-Nov-2011
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Contact: Jill Scoggins
jill.scoggins@louisville.edu
502-852-7461
University of Louisville

LOUISVILLE, Ky. ? A University of Louisville scientist has determined for the first time how the bacterium that causes Legionnaires' disease manipulates our cells to generate the amino acids it needs to grow and cause infection and inflammation in the lungs. The results are published online today (Nov. 17) in "Science."

Yousef Abu Kwaik, Ph.D., the Bumgardner Endowed Professor in Molecular Pathogenesis of Microbial Infections at UofL, and his team believe their work could help lead to development of new antibiotics and vaccines.

"It is possible that the process we have identified presents a great target for new research in antibiotic and vaccine candidates, not only for Legionnaires' disease but in other bacteria that cause illness," he said.

According to the Centers for Disease Control and Prevention, Legionnaires' disease is a lung infection caused by the bacterium called Legionella. The bacterium got its name in 1976, when many people who went to a Philadelphia convention of the American Legion suffered from an outbreak of pneumonia of unknown causes that was later determined to be caused by the bacterium. Each year, between 8,000 and 18,000 people are hospitalized with Legionnaires' disease in the U.S. There is no vaccine currently available for it.

For two years, the researchers examined Legionella which is an intercellular bacterium that exists in amoebae in the water systems; it is transmitted to humans through inhalation of water droplets. Cooling towers and whirlpools are the major sources of transmission. The bacterium uses the amoeba's cellular process to "tag" proteins, causing them to degrade into their basic elements of amino acids. These amino acids are used by the bacteria as the main source of energy to grow and cause disease.

"The bacteria live on an 'Atkins diet' of low carbs and high protein, and they trick the host cell to provide that specialized diet," Abu Kwaik said.

The same process occurs in a host ? animal or human ? who inhales the bacterium and is diagnosed with Legionnaires' disease. However, the bacteria do not tag the proteins, but rather trick the host into tagging the proteins for degradation to generate the amino acids.

In the laboratory, Abu Kwaik and his team saw that by inactivating the bacterial virulence factor responsible for tricking the cell into tagging proteins for degradation in mice models, the pulmonary disease was totally prevented. This was totally due to disabling the bacteria from generating amino acids, he said.

The process was then reversed, and the disease became evident when the mice, infected by the disabled bacteria, were injected with amino acids to compensate for the inability of the altered bacteria.

"Bacteria need to live on high protein and amino acids as sources of nutrition and energy in order to replicate in a host. This is what causes pulmonary disease," Abu Kwaik said. "No one has known how they generate sufficient sources of nutrients from the host to proliferate. Our work is the first to identify this process for any bacteria that cause disease."

He added that the type of host infected does not appear to affect the process. "Whether in a single-cell amoeba or a multi-cellular mammal, Legionella seems to know what to do; the process is the same, and is highly conserved through evolution. By interfering with the bacterium's sources of nutrients, we can stop it from thriving and causing disease."

Examining nutrient sources for organisms with the goal of stopping them from acquiring nutrients is a relatively new arena of basic research that deserves further study, he said. "We went after the basics ? the food and energy source ? which are prerequisite for the bacteria to grow and cause disease. It is not a process that is well understood yet, but by first discovering how an organism gets nutrients by tricking the host into degrading proteins, and then interfering with that process, we can, in effect, starve it to death and prevent or treat the disease."

With Abu Kwaik, authors of the paper are Christopher T.D. Price, Ph.D. and Tasneem Al-Quadan, a doctoral student, in UofL's Department of Microbiology and Immunology; Marina Santic, Ph.D., of the University of Rijeka, Croatia; and Ilan Rosenshine, Ph.D., of the Hebrew University Medical School in Jerusalem, Israel.

The work was funded by a grant from the National Institute of Allergy and Infectious Diseases.

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Researcher Determines How Legionnaires' Bacteria Proliferate, Cause Disease

Main Category: Infectious Diseases / Bacteria / Viruses
Also Included In: Respiratory / Asthma
Article Date: 21 Nov 2011 - 0:00 PST

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A University of Louisville scientist has determined for the first time how the bacterium that causes Legionnaires' disease manipulates our cells to generate the amino acids it needs to grow and cause infection and inflammation in the lungs. The results are published online in Science.

Yousef Abu Kwaik, Ph.D., the Bumgardner Endowed Professor in Molecular Pathogenesis of Microbial Infections at UofL, and his team believe their work could help lead to development of new antibiotics and vaccines.

"It is possible that the process we have identified presents a great target for new research in antibiotic and vaccine candidates, not only for Legionnaires' disease but in other bacteria that cause illness," he said.

According to the Centers for Disease Control and Prevention, Legionnaires' disease is a lung infection caused by the bacterium called Legionella. The bacterium got its name in 1976, when many people who went to a Philadelphia convention of the American Legion suffered from an outbreak of pneumonia of unknown causes that was later determined to be caused by the bacterium. Each year, between 8,000 and 18,000 people are hospitalized with Legionnaires' disease in the U.S. There is no vaccine currently available for it.

For two years, the researchers examined Legionella which is an intercellular bacterium that exists in amoebae in the water systems; it is transmitted to humans through inhalation of water droplets. Cooling towers and whirlpools are the major sources of transmission. The bacterium uses the amoeba's cellular process to "tag" proteins, causing them to degrade into their basic elements of amino acids. These amino acids are used by the bacteria as the main source of energy to grow and cause disease.

"The bacteria live on an 'Atkins diet' of low carbs and high protein, and they trick the host cell to provide that specialized diet," Abu Kwaik said.

The same process occurs in a host - animal or human - who inhales the bacterium and is diagnosed with Legionnaires' disease. However, the bacteria do not tag the proteins, but rather trick the host into tagging the proteins for degradation to generate the amino acids.

In the laboratory, Abu Kwaik and his team saw that by inactivating the bacterial virulence factor responsible for tricking the cell into tagging proteins for degradation in mice models, the pulmonary disease was totally prevented. This was totally due to disabling the bacteria from generating amino acids, he said.

The process was then reversed, and the disease became evident when the mice, infected by the disabled bacteria, were injected with amino acids to compensate for the inability of the altered bacteria.

"Bacteria need to live on high protein and amino acids as sources of nutrition and energy in order to replicate in a host. This is what causes pulmonary disease," Abu Kwaik said. "No one has known how they generate sufficient sources of nutrients from the host to proliferate. Our work is the first to identify this process for any bacteria that cause disease."

He added that the type of host infected does not appear to affect the process. "Whether in a single-cell amoeba or a multi-cellular mammal, Legionella seems to know what to do; the process is the same, and is highly conserved through evolution. By interfering with the bacterium's sources of nutrients, we can stop it from thriving and causing disease."

Examining nutrient sources for organisms with the goal of stopping them from acquiring nutrients is a relatively new arena of basic research that deserves further study, he said. "We went after the basics - the food and energy source - which are prerequisite for the bacteria to grow and cause disease. It is not a process that is well understood yet, but by first discovering how an organism gets nutrients by tricking the host into degrading proteins, and then interfering with that process, we can, in effect, starve it to death and prevent or treat the disease."

Article adapted by Medical News Today from original press release. Click 'references' tab above for source.
Visit our infectious diseases / bacteria / viruses section for the latest news on this subject. With Abu Kwaik, authors of the paper are Christopher T.D. Price, Ph.D. and Tasneem Al-Quadan, a doctoral student, in UofL’s Department of Microbiology and Immunology; Marina Santic, Ph.D., of the University of Rijeka, Croatia; and Ilan Rosenshine, Ph.D., of the Hebrew University Medical School in Jerusalem, Israel.
The work was funded by a grant from the National Institute of Allergy and Infectious Diseases.
University of Louisville Please use one of the following formats to cite this article in your essay, paper or report:

MLA

University of Louisville. "Researcher Determines How Legionnaires' Bacteria Proliferate, Cause Disease." Medical News Today. MediLexicon, Intl., 21 Nov. 2011. Web.
8 Dec. 2011. APA

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How Legionnaires' bacteria proliferate, cause disease

Scientist have determined for the first time how the bacterium that causes Legionnaires' disease manipulates our cells to generate the amino acids it needs to grow and cause infection and inflammation in the lungs. (Source: ScienceDaily Headlines)

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How Legionnaires' bacteria cause disease

LOUISVILLE, Ky., Nov. 18 (UPI) -- A bacterium that causes Legionnaires' disease manipulates cells to generate amino acids it needs to grow and infect the lungs, U.S. researchers say. (Source: Health News - UPI.com)

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UofL researcher determines how Legionnaires' bacteria proliferate, cause disease

(University of Louisville) A University of Louisville scientist has determined for the first time how the bacterium that causes Legionnaires' disease manipulates our cells to generate the amino acids it needs to grow and cause infection and inflammation in the lungs. The results are published online today (Nov. 17) in Science. (Source: EurekAlert! - Medicine and Health)

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