Welcome to the Microbiology Information

Healthy consumers can handle the low levels of bacteria occasionally found in cosmetics. But for severely ill patients these bacteria may trigger life-threatening infections, as patients in the intensive care unit at one Barcelona hospital discovered after using contaminated body moisturiser. The Burkholderia cepacia bacteria outbreak is detailed in the open access journal, Critical Care.

Five patients suffered from infection including bacteremia, lower respiratory tract infection and urinary tract infection associated with the bacterial outbreak in August 2006. Skin care products sold in the European Union are not required to be sterile, but there are limits to the amount and type of bacteria that are permitted. The Hospital Universitari del Mar, Universitat Autònoma de Barcelona’s routine infection control surveillance pinpointed the unwelcome bacteria in five patients’ biological samples.

Researchers tested a number of environmental samples, and discovered that moisturizing body milk used in the patients’ care was a B. cepacia reservoir. Pulsed-field gel electrophoresis experiments confirmed that all of the strains of B. cepacia bacteria found in patient and environmental samples were from the same bacterial clone. Tests on sealed containers of the moisturizer confirmed that the bacteria had not invaded the product after it had been opened, but that it was contaminated during manufacturing, transportation or
storage.

“This outbreak of nosocomial infection caused by B. cepacia in five severely ill patients supports a strong
recommendation against the use cosmetic products for which there is no guarantee of sterilization during the manufacturing process,” says study author Francisco Álvarez-Lerma. B. cepacia is a group or “complex” of bacteria that can be found in soil and water. They have a high resistance to numerous antimicrobials and antiseptics and are characterised by the capacity to survive in a large variety of hospital microenvironments These bugs pose little medical risk to healthy people. However, those with weakened immune systems or chronic lung diseases, particularly cystic fibrosis, may be more susceptible to B. cepacia infection. B
cepacia is a known cause of hospital infections.

Moisturizing body milk as a reservoir of Burkholderia cepacia: outbreak of nosocomial infection in a multidisciplinary intensive care unit. Francisco Alvarez-Lerma, Elena Marull, Roser Terradas, Concepcion Segura, Irene Planells, Pere Coll, Hernando Knobel and Antonia Vazquez. Critical Care (in
press).

Listeria appears again – but this time in sandwiches wwhere it was sold to 20 people at Middlemore Hospital in New Zealand.

These pre-packaged Thai chicken sandwiches were sold on Monday at the hospital’s Aviary Cafe, which is mainly used by staff.

The contamination was detected in routine listeria testing where the results were given to the hospital yesterday.

It was not known last night whether other sandwich varieties at the cafe were infected, or if other products from the sandwiches’ supplier, Naturezone, were infected with listeria and had been distributed to other outlets.

The bacterium can be fatal to people with low immune systems and can cause miscarriages or stillbirths if it infects pregnant women.

A spokeswoman for Spotless Services, the company that runs the cafe, said it was not yet known how many of its outlets had been stocked with the sandwiches. Naturezone could not be reached for comment last night.

Auckland Regional Public Health Service spokesman Dr Greg Simmons said last night that greatly improved methods of testing were bringing the listeria cases to the surface.

All positive tests in the past three weeks had come from the same testing facility.

“We are conducting a thorough site inspection at the company and we will ensure extensive product and environmental testing to identify the source,” Dr Simmons said

Despite the relatively low risk, he said, it was a serious situation.

“We are concerned that a whole lot of ready-to-eat products look like they are being contaminated. We would be silly not to be concerned.”

The bacterium usually produces fever, diarrhoea and general unwellness within three weeks of infection, although it can take as long as 10 weeks for symptoms to show.

Here is a load of crap, pajamas that is designed to protect against MRSA by incorporating silver into its fabric at a level of 2%.

They claim that by having 2% silver woven into its fabric, it can protect against the hospital super bug MRSA. It has already gone on sale UK with M&S the first British retailer to stock the £45 Sleep Safe pajamas and is trialing them at 100 stores.

Silver is known for its infection-fighting properties and silver-laced nightwear has already been tested in a handful of hospitals.

But campaigners called the pajamas a gimmick and said the only way to tackle MRSA was by making hospitals cleaner.

MRSA

MRSA (methicillin resistant Staphylococcus aureus) is a bacterium that can live completely harmlessly on the skin of healthy people but can lead to serious infection.

MRSA infections can cause a broad range of symptoms depending on the part of the body that is infected. These may include surgical wounds, burns, catheter sites, eye, skin and blood.

Dr Mark Enright, a microbiologist at Imperial College London, said that the pajamas would reduce the risk of a patient getting a skin infection that enters a wound.

The problem lies within the hospitals. They are dirty and it should not be up to the public to safeguard themselves

Tony Kitchen of MRSA Support

A spokesman for M&S said: “The fabric that the pajamas are made of has been clinically proven to reduce the risk of MRSA by killing bacteria that come into contact with the fabric.

“Clinical trials are currently ongoing and are three quarters of the way through. The interim results were positive.”

They are only available for men at present and are produced using a fabric which 2% silver has woven into it.

Katherine Murphy, from the Patients’ Association, said: “We welcome the fact these are going on sale, but it shows how desperate the public is.”

However, Tony Kitchen of MRSA Support said: “It sounds like a gimmick – it cannot be a super suit and probably doesn’t make a jot of difference.

“The problem lies within the hospitals. They are dirty and it should not be up to the public to safeguard themselves, it’s the ethos of the hospital that needs to change.”

A spokesman added that if the pajamas did prove effective then they ought to be provided by the health service. rather than paid for by the patient.

The EU and US positions at a Codex meeting to set international standards on food safety foreshadow future legislation that would affect hygiene control measures in manufacturing plants, and the manufacture of powdered formulae, ready-to-eat foods, and pasteurised liquid eggs.

In the six day meeting which ended on the 4 November in New Delhi, India, national representatives to Codex’s food hygiene committee also decided to start work on drafting safety guidelines setting standards to control Campylobacter and Salmonella specie in broiler chicken meat.

At the New Delhi meeting they discussed various positions, including those relating to proposed standards for pasteurized liquid whole eggs, hygienic practice for processing powdered formulae for infants and children, pathogen control measures for Listeria monocytogenes in ready-to-eat foods & guidelines for evaluating manufacturing control measures.

Codex is a multilateral body set up to develop food safety and other standards that would apply to all member countries.

It operates under the aegis of the UN’s Food and Agriculture Organisation and the World Health Organisation.

The standards are recognised as international benchmarks by one of the multilateral agreements of the World Trade Organisation (WTO) and aim to eliminate many of what the UN calls “unjustified technical barriers” to food imports set up by some countries.

The standards also serve to harmonise food safety laws globally, aiding multinational processors in following the law no matter where they trade.

The standards on each particular topic and food type can undergo a huge revision process at various levels of Codex decision making bodies, over a number of years. Member countries must then transcribe the standards into their national laws.

The proposed standard setting what pathogen controls for Listeria monocytogenes ready-to-eat food processors must put in place is based in the main on US risk assessments, according to Codex documents.

Based on the risk assessments, a working group led by Germany concluded that a zero tolerance standard for L. monocytogenes have a proportional reduction in the rates of illness from foods contaminated with the pathogen.

A study commissioned by the food hygiene committee showed that the application of microbiological criteria at a given point of the production chain is only one of the measures that need to be applied, to bring down contamination rates.

The committee proposes to exclude from the criteria foods that are processing in such a way to ensure the killing of L. monocytogenes and for which recontamination is not possible.

The foods must also be processed and handled under systems adhering to good hygienic practice (GHP), a separate international standard.

Such foods include those given a listericidal treatment in the package and those that are produced through aseptic processing and packaging.

The group includes dehydrated products such as powdered milk, dehydrated soup mixes, herbs and spices, fresh, uncut and unprocessed vegetables and fruits, soft drinks, beer and spirits.

At the meeting the EU delegation also proposed that the standard should specifically include ready-to-eat foods for infants and those with medical conditions.

The EU supports a 100 colony forming units per gram (cfu/g) limit on the pathogen for ready-to-eat foods, if the food manufacturer is able to demonstrate the maximum would not be exceeded throughout the shelf-life.

The EU delegation also noted that setting a zero tolerance standard, where a negative reading is set at 25g = 0.04 colony forming units per gram (cfu/g) “might cause misunderstandings”.

The EU also wants clarification on foods not covered by the testing standard, pointing out that previous discussions had also discussed products for which Listeria monocytogenes is “very unlikely” to be detected.

Clarification is also needed about the proposed exclusion of foods for which there is less than ’1 log’ growth during 1.3 times the expected shelf life, the EU stated in its submission. Various definitions of ‘shelf-life’ might confuse the issue.

At the meeting the Codex committee also set its priorities for proposed standards, with those for egg products topping the list.

Other priorities in order are standards for infant and children foods; combining two codes of practice for various nuts into one; setting a single hygienic code for fruits, vegetable and products made from them; quick frozen foods, spices and aromatic plants; low-acid and acidified low-acid canned foods and aseptically processed and packaged low-acid canned foods, natural mineral waters, frog legs, catering, and street-vended foods.

The WTO’s Codex Alimentarius Commission is the body set up to harmonise food safety and other export requirements around the world.

Member countries’ representatives meet regularly to debate a common position or standard on every aspect of such requirements, from the holding temperatures in frozen meat should be kept at, to processing requirements for specific types of cheeses.

Agreements forged at Codex meetings could eventually affect the way processors operate worldwide as they become incorporated into national laws in various countries around the world.

Source

Helmholtz Association of German Research Centres – Science Daily — A German-American research team of biologists and geochemists has discovered hitherto unknown anaerobic bacteria in marine sediments which need only propane or butane for growth, as recently reported by the scientific journal “Nature.”

The hydrocarbons ethane, propane and butane — as well as the main component, methane — are the major constituents of natural gas.

Biological processes may lead to the degradation of these hydrocarbons in underground petroleum reservoirs and other geological habitats.

Heinz Wilkes, a leading biogeochemist at GeoForschungsZentrum Potsdam (GFZ), points out: “The bacteria isolated here for the first time from marine sediments use sulphate instead of oxygen for respiration and utilize propane and butane as their sole source of carbon and energy. These organisms are tough specialists that have become adapted to strictly utilising only these and no other substrates.”

The investigations showed that the bacteria employ an unprecedented biochemical mechanism for transforming what are essentially unreactive hydrocarbons into reactive metabolites which may then be further oxidised to carbon dioxide.

The findings concerning this reaction mechanism are an important step in designing new synthetic methods for selectively producing chemicals from hydrocarbons.

North Carolina Sea Grant researchers have isolated a new peptide antibiotic from the American oyster that may have implications for managing many diseases in oysters.

The new antimicrobial peptide “American oyster defensin” (AOD) may protect against bacteria in Crassostrea virginica, a species that is native to North Carolina and important economically to Atlantic and Gulf Coast fisheries.

“This peptide may be helpful in selecting disease-resistant oysters for aquaculture and fisheries and may also allow for the development of a test to monitor oyster health,” says Ed Noga, professor at the North Carolina State University College of Veterinary Medicine.

“In recent years, a number of pathogens, especially bacteria and parasites, have devastated American oyster populations.”

The research findings appear in the new (Dec. 30) issue of Biochemical and Biophysical Research Communications.

Pathogens such as dermo (Perkinsus marinus) have caused major decreases in oyster productivity — bacterial pathogens — such as Vibrio vulnificus that can cause a food-borne illness are a human health concern, according to Noga.

This is the first time that researchers have isolated an antimicrobial peptide from any oyster species, he says.

NC State veterinary medicine postdoctoral research associate Jung-Kil Seo, as well as scientists J. Myron Crawford and Kathryn L. Stone of Yale University’s Keck Biotechnology Resource Laboratory, collaborated with Noga on the study.

“The results may be used to better understand the innate immune system of American oysters and to enhance research to protect it from important microbial infections,” according to Noga.

“Further studies are needed to identify sites of synthesis and storage of AOD and determine mechanisms affecting its regulation.”

According to New Scientist, “A comprehensive analysis of both the molecular genetic and phenotypic responses of any organism to the space flight environment has never been accomplished because of significant technological and logistical hurdles.”……until now.

Bacteria flown on the space shuttle mutated in ways that made them nearly three times more deadly to mice, reports a new study. While the bugs are also likely to affect astronauts’ health, the research team found clues that may help render them harmless.

Astrobiologists have long been worried that the low-gravity conditions of space could make disease-causing microbes that hitch-hike on shuttle missions mutate in unpredictable ways. To investigate, Cheryl Nickerson at Arizona State University in Tempe, US, and her colleagues launched flasks of the bacterium Salmonella typhimurium into space on the shuttle Atlantis in September 2006.

The shuttle returned after 12 days, during which time the microbes had altered the way they express 167 genes compared with bacteria that remained on Earth. The team found that these space-mutated bugs were almost three times as likely to kill infected mice compared with their ground-grown counterparts.

That could be bad news if the results hold true for astronauts, since some experiments suggest the weightlessness of space travel suppresses the immune system.

But the news is not all bad. Nickerson and her colleagues also identified the protein, called Hfq, believed to be behind the change. “An overwhelming number of the [affected] genes are regulated by Hfq,” she says.

Archilles’ Heel
Strains of Salmonella without normally functioning Hfq did not show the gene expression changes when they were tested under microgravity conditions in the lab. Nickerson says this knowledge could one day be leveraged to “design targeted strategies and countermeasures to mitigate infectious disease risks to the crew during future missions”.

The work may also help combat Salmonella on Earth. Micro-organisms growing in a liquid in microgravity experience low fluid forces that are similar in many ways to those that the bugs encounter on Earth inside their hosts, she explains. “An exciting part of this work is the opportunity to use spaceflight as a novel research platform for innovations in infectious disease control here on Earth,” she told.

Robert McLean, a microbiologist at Texas State University in San Marcos, US, who has also flown bacterial experiments on space shuttles, is impressed with the new study.

“On Earth, we’re so used to gravity that we ignore it, but for the first time we’re seeing that gravity may be needed for genes to be expressed,” he told New Scientist. “I think that transcends the space programme, and tells us something hugely important about biology in general.”

An unexpected find by a team of University of Georgia scientists suggests that reducing the use of antibiotics on poultry farms will do little, if anything to reduce rates of antibiotic resistant bacteria that have the potential to threaten human health.

Dr. Margie Lee, professor in the UGA College of Veterinary Medicine, and her colleagues have found that chickens raised on antibiotic-free farms and even those raised under pristine laboratory conditions have high levels of bacteria that are resistant to common antibiotics. Her findings, published in the March issue of the journal Applied and Environmental Microbiology, suggest that poultry come to the farm harboring resistant bacteria, possibly acquired as they were developing in their eggs.

“The resistances don’t necessarily come from antibiotic use in the birds that we eat,” Lee said, “so banning antibiotic use on the farm isn’t going to help. You have to put in some work before that.”

Lee and her team sampled droppings from more than 140,000 chickens under four different conditions: 1.) commercial flocks that had been given antibiotics; 2.) commercial flocks that had not been given antibiotics; 3.) flocks raised in a lab that had been given antibiotics; and 4.) flocks raised in a lab that had not been given antibiotics. The researchers examined levels of antibiotic resistance in normal intestinal bacteria that do not cause human illness and – in a companion study published in May in the same journal – also examined levels of drug resistant campylobacter bacteria, a common food-borne cause of diarrhea, cramping and abdominal pain.

They found that even chickens raised in the pristine laboratory conditions had levels of antibiotic resistance levels comparable to what was seen on farms that used antibiotics. Even when the levels were lower, Lee adds, they were still well above the reasonable comfort zone for antibiotic resistance – roughly five to 10 percent.

Seventy-three percent of the bacteria from one flock in the antibiotic-free commercial group were resistant to the drug oxytetracycline, for example, while 90 percent were resistant to the drug in a commercial flock that used antibiotics. Ninety-seven percent were resistant in the experimental flock that was given antibiotics, while forty-seven percent were resistant in the experimental group that was not given antibiotics.

Strikingly, they even found bacteria resistant to streptomycin, a common human antibiotic that is rarely used in poultry and was not used on the farms the researchers studied.

Bacteria swap genes relatively easily, and Lee explained that the concern is that drug resistance genes from bacteria that infect poultry could be passed on to bacteria that cause human illness. With these resistance genes, human bacterial illness could become harder to treat.

These concerns led the European Union to ban the use of antibiotics for growth promotion in chickens in 2006. In 2005, the U.S. Food and Drug Administration banned the use of the drug Baytril (the brand name for enrofloxacin, a fluoroquinolone antibiotic) in poultry, citing concerns that it could lead to resistance in human antibiotics such as Ciprofloxacin, also a fluoroquinolone.

Several advocacy groups are pushing for a more comprehensive animal antibiotic ban in the United States, but Lee said her research plus the evidence from the Baytril ban suggests that approach won’t help.

“They banned Baytril in 2005, and if you look at Baytril resistance in campylobacter now it’s essentially unchanged,” Lee said.

In previous studies, Lee has tried to recreate experimentally conditions that should lead to the swapping of resistance genes among bacteria. Lee said these events – known as the horizontal transfer of genes – do occur, but they may not be as common as initially thought.

What may be driving the antibiotic resistance that Lee has observed in her studies is what’s known as vertical transfer – from parent to child – of bacteria carrying resistance genes. In short, the birds may come to the farm harboring antibiotic resistant bacteria.

“This issue of antibiotic resistance is more complicated than once thought,” Lee said. “These findings suggest that banning antibiotics at the farm level may not be as effective as assumed. We need further studies to identify which management practice would be effective”

Lee stresses that for consumers, the advice on poultry is the same that it’s always been. Cook meat thoroughly and use proper food handling and preparation techniques – washing your hands regularly and keeping other foods away from raw chicken, for example – to minimize the risk of illness.

“All foods have the potential to contain pathogens – all of them,” Lee said. “There’s no substitute for good food handling and preparation.”

The study was funded by grants from the FDA and the United States Department of Agriculture.

Putting bacteria on birth control could stop the spread of drug-resistant microbes, and researchers at the University of North Carolina at Chapel Hill have found a way to do just that.

The team discovered a key weakness in the enzyme that helps “fertile” bacteria swap genes for drug resistance. Drugs called bisphosphonates, widely prescribed for bone loss, block this enzyme and prevent bacteria from spreading antibiotic resistance genes, the research shows. Interfering with the enzyme has the added effect of annihilating antibiotic-resistant bacteria in laboratory cultures. Animal studies of the drugs are now underway.

“Our discoveries may lead to the ability to selectively kill antibiotic-resistant bacteria in patients, and to halt the spread of resistance in clinical settings,” said Matt Redinbo, Ph.D., senior study author and professor of chemistry, biochemistry and biophysics at UNC-Chapel Hill.

The study provides a new weapon in the battle against antibiotic-resistant bacteria, which represent a serious public health problem. In the last decade, almost every type of bacteria has become more resistant to antibiotic treatment. These bugs cause deadly infections that are difficult to treat and expensive to cure.

Every time someone takes an antibiotic, the drug kills the weakest bacteria in the bloodstream. Any bug that has a protective mutation against the antibiotic survives. These drug-resistant microbes quickly accumulate useful mutations and share them with other bacteria through conjugation — the microbe equivalent of mating.

Conjugation starts when two bacteria ‘smoosh’ their membranes together. After each opens a hole in their membrane, one squirts a single strand of DNA to the other. Then the two go on their merry way, one with new genes for traits such as drug resistance. Many highly-drug resistant bacteria rely on an enzyme, called DNA relaxase, to obtain and pass on their resistance genes. A mutation that provides antibiotic resistance can then sweep through a colony as quickly as the latest YouTube hit.

The researchers analyzed relaxase because it plays a crucial role in conjugation. The enzyme starts and stops the movement of DNA between bacteria. “Relaxase is the gatekeeper, and it is also the Achilles’ heel of the resistance process,” Redinbo said.

Led by graduate student Scott Lujan, the team suspected they could block relaxase by searching for vulnerability in a three-dimensional picture of the relaxase protein. Lujan, a biochemistry graduate student in the School of Medicine, confirmed the hunch using x-ray crystallography, which creates nanoscale structural images of the enzyme.

The researchers predicted that the enzyme’s weak link is the spot where it handles DNA. Relaxase must juggle two phosphate-rich DNA strands at the same time. The team suspected a chemical decoy — a phosphate ion — could plug this dual DNA binding site. Redinbo, who has a background in cancer and other disease-related research, realized that bisphosphonates were the right-size decoy.

There are several bisphosphonates on the market; two proved effective. The drugs, called clodronate and etidronate, steal the DNA binding site, preventing relaxase from handling DNA. This wreaks havoc inside E. coli bacteria that are preparing to transfer their genes, the researchers found. Exactly how bisphosphonates destroy each bacterium is still unknown, Redinbo said, but the drugs are potent, wiping out any E. coli carrying relaxase. “That it killed bacteria was a surprise,” he said. By targeting these bacteria, the drugs act like birth control and prevent antibiotic resistance from spreading.

Redinbo, who cautions that the results only apply to E. coli, said further testing will reveal whether bisphosphonates also attack similar species like Acinetobacter baumannii (hospital-acquired pneumonia), Staphylococcus aureus (staph infections) and Burkholderia (lung infections).
“We hope this discovery will help existing antibiotics or offer a new treatment for antibiotic-resistant bacteria,” he said.

The drugs may be most effective at sites where clinicians can best control dosage — on skin and in the gastrointestinal tract, Redinbo said. Other applications may include disinfectants and treatments for farm animals.

Study co-authors, all from UNC-Chapel Hill, include Laura Guogas, Heather Ragonese and Steven Matson. Redinbo is a member of the UNC Lineberger Comprehensive Cancer Center.
Redinbo and his colleagues have filed a patent and formed a small company to further develop the technology.

The study appears online the week of July 9, 2007, in the Proceedings of the National Academy of Sciences. Funding was provided by the National Institutes of Health.

Source

The effort to find preserved samples of the 1918 influenza virus has been a pursuit of both historical and medical importance.

The influenza pandemic in 1918 was the most devastating single disease outbreak in modern history, and examining the virus that caused it may help prepare for, and possibly prevent, future pandemics. When the complete sequence of the 1918 virus was published in 2005, it represented a watershed event for influenza researchers worldwide.

An article in the journal Antiviral Therapy, scientists at the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, narrate the story of how scientists discovered samples of the 1918 strain in fixed autopsy tissues and in the body of a woman buried in the Alaskan permafrost.

The article places this discovery in the context of decades of research into the cause of pandemic influenza, and the authors detail the strange convergence of events that allowed them to recover and sequence the virus in the first place. Its genetic material is so fragile that it should not have survived for days, let alone decades.

In a mass grave in a remote Inuit village near the town of Brevig Mission, a large Inuit woman lay buried under more than six feet of ice and dirt for more than 75 years. The permafrost plus the woman’s ample fat stores kept the virus in her lungs so well preserved that when a team of scientists exhumed her body in the late 1990s, they could recover enough viral RNA to sequence the 1918 strain in its whole entirety. This remarkable good fortune enabled these scientists to open a window onto a past pandemic. It could also help mankind gain a foothold for preventing a future one.