Enterococci are normal gut flora that are found in most humans. The two major species that live in and effect humans are Enterococcus faecalis and Enterococcus faecium (the species name gives you some idea of where and how they are distributed as well).
A recent report out of Sweden is describing the growing incidence of vancomycin resistant enterococci (VRE) in hospital patients. And by growing, I mean exploding. In the report, they stated that from from all of 2000 until 2006 they saw a total of 197 cases of patients that were colonized or infected with VRE. From July 2007 until February 2009 they saw an astounding total of 760 cases reported.
How does E. facalis gain the ability to resist treatment with vancomycin? It obtains a plasmid that confers high level resistance to this antibiotic. This is a problem because gut bacteria can conjugate and spread the plasmid to other organisms that live in the gut. (E. coli, another gut resident, is gram negative and therefore already innately resistant to treatment with vancomyin).
Additionally? Enterococci are either innately resistant to or have acquired resistance to:
penicillinase-susceptible penicillin (low level), penicillinase-resistant penicillins, cephalosporins, nalidixic acid, aztreonam, macrolides, and low levels of clindamycin and aminoglycosides. They use already-formed folic acid, which allows them to bypass the inhibition of folate synthesis, resulting in resistance to trimethoprim-sulfamethoxazole.
Enterococci also have acquired resistance, which includes resistance to penicillin by beta-lactamases, chloramphenicol, tetracyclines, rifampin, fluoroquinolones, aminoglycosides (high levels)
The presence and increasing incidence of antibiotic resistant bacteria should be making us all much more conscious of how and when we use antibiotics. The problem? We think we know when and how to take antibiotics.
More on this tomorrow…
Tags: Antibiotic resistance, VRE
The New York Times has an article that details an art exhibit of viral particles created out of glass by sculptor Luke Jerram. They are fairly accurate representations of viruses such as HIV and Hepatitis C virions. In glass. They are breathtaking.
But as beautiful as they are, my favorite quote was from the article’s author regarding the artist and his sculptures and science:
he groused in a way that would endear him to any grumpy science-journalism hack.
“I’m just now on the front page of one of the Nature journals,” he said. “But they used one of my swine flu sculptures to illustrate H.I.V. You’d think they would have known better.”
Thanks to Brandy Dykhuizen for the article.
Most of my students are afraid of bacteria. They hear in the news how various types of bacterial infections are causing daily doses of death and disease. But…we also need to remember how important bacteria are to our global health and well being. We know that bacteria help recycle plant and animal matter. Oil eating bacteria are being put to work at helping clean up the oil spill in the Gulf. Probiotics are proving to be great examples of how keeping our commensals healthy keeps our gut healthy. Contact with everyday bacteria can keep you from developing allergies and asthma.
And on top of all that goodness, recent research presented at the ASM (American Society for Microbiology) meeting in San Diego is telling us that some bacteria can actually MAKE YOU SMART and HAPPY! Really. Not all bacteria, but a specific common soil bacteria found everywhere, called Mycobacterium vaccae.
In 2007, scientists demonstrated that this bacterium, when used as a vaccine, can have effects on humans that are similar to those seen with antidepressants (by increasing seratonin levels in the brain). The current study (in which mice were fed these bacteria) demonstrated that the mice eating M vaccae learned faster and were less anxious than controls not receiving the bacteria. If the mice stopped receiving the bacteria they lost the edge they had gained on the control animals.
It is interesting to think of people taking pills filled with bacteria daily to get this effect. But you have access to this breaking science right now. This your prescription: Go outside and get those hands dirty, and play in the mud!
I have heard a lot of my friends extol the virtues of drinking raw milk. There are many websites devoted to the benefits and life experiences obtained from the drinking of raw milk. I grew up drinking raw milk. However, I am not pro- or con-raw milk. I am just a voice of consequence. You could get sick from consuming raw milk.
The latest illness associated with drinking raw milk involves an outbreak of campylobacter infections in Utah. Symptoms of infections with Camyplobacter jejuni?:
mild to severe infection of the gastrointestinal system, including watery or bloody diarrhea, fever, abdominal cramps, nausea, and vomiting.
Earlier, there had been an outbreak of salmonella linked to the same dairy. Yes, I know, it is essentially the dairy’s responsibility, but I am just reminding you, you can get sick from drinking raw milk. Other outbreaks associated with raw milk consumption have included E. coli O157:H7 as well as listeriosis.
California has seen a doubling of whooping cough infections in the first three months of this year as compared to what was seen in 2009 (219 vs 119, respectively). There have been two deaths of infants from the infection already this year. This infection (caused by Bordetella pertussis) is more severe in infants and children than adults. From the CDC:
Pertussis is worse for very young children; more than half of infants less than 1 year of age who get the disease must be hospitalized. About 1 in 10 children with pertussis get pneumonia (lung infection), and about 1 in 50 will have convulsions.
Adult infections are generally milder and individuals may not even know they are infected. However, they can be carriers/transmitters of disease to younger children. According to the California report:
most cases of whooping cough in infants under six months come from the mother. The public health department recommends that all parents be given the vaccine before leaving the hospital with a new baby.
Boosters are necessary every 10 years. In an outbreak of whooping cough that is occurring in Minnesota, 46 elementary students have developed the disease, with the highest rate in the fifth and sixth grade levels. Most of these students have been vaccinated with the TDaP vaccine, but they are due to have a booster in 7th grade. Officials are wondering if the increasing number of infections at the fifth and sixth grade levels mean that age should be adjusted. (the CDC recommends giving the booster between the ages of 11 and 18).
Since the 15th century, the organism that causes syphilis, Treponema pallidum, has been responsible for producing vast amounts of human misery by being a major cause of blindness, heart disease, insanity and even death. But since the discovery of antibiotics, syphilis infections can be cured with a simple injection of penicillin. We had it so well in control in the 1950′s it was thought to have been eradicated from the US.
However, syphilis appears not only to have made a comeback, but appears to be quickly gaining ground. The CDC reported an 11.8% increase in cases from 2005 to 2006. In November of 2009, there was a report out that the infection rate for North Carolina had DOUBLED for syphilis infections from the previous year.
A new report out by the New England Journal of Medicine (via the BBC) is stating that a similar trend is occurring now in China. Having been almost eradicated in the 1950′s, the report states that currently 20 people in every 100.000 people carry the disease. So, let’s see…China has a population of 1.3 billion people (as of 2008) . That would make over 260,000 people infected with the organism. But what is especially distressing the rate of congenital syphilis (infection of the newborn):
Pregnant women are also increasingly passing the disease to their children, with more than one baby with congenital syphilis born every hour in 2008.
EVERY HOUR. Since 2008, that means over 12,000 babies have been born with the disease. Symptoms of congenital syphilis are:
deformities, neurological problems, stillbirths or death in early infancy
And (as always in this blog) we are also going to talk about antibiotic resistance. Syphilis is becoming increasingly resistant to treatment with azithromycin. However, it is interesting that it is not yet resistant to treatment with penicillin. However, could that be on the way? According to one report it would only take a mutation in one enzyme necessary for cell wall synthesis (a penicillin binding protein) for the organism to become resistant to that as well.
It is a scary monster indeed.
There are recent reports out about an outbreak of meningitis in a school district in Oklahoma. Why this hasn’t made national news is that the infections have been verified to be viral meningitis. Viral meningitis (also called aseptic meningitis ) is caused predominantly in the US by enteroviruses. These viruses can be spread via respiratory secretions (kissing, sneezing, sharing drinks) as well as through fecal contamination of ingested foods. Infections with these viruses usually cause mild symptoms (which can vary depending on age). Most symptoms include stiff neck. fever, vomiting and nausea. However, treatment is simple bed rest and patients were sent home to recover on their own.
So what is the difference between viral and bacterial meningitis?
Bacterial meningitis can be much more deadly and requires hospitalization and treatment with antibiotic therapy. One form, called meningococcal meningitis is actually very deadly. It can cause severe disease such as brain damage, hearing loss, loss of limbs, coma and death if not treated with antibiotics in a timely manner. Outbreaks in the US are usually limited to a few individuals. As a matter of fact, the same region of Oklahoma had an outbreak of meningococcal meningitis in March, in which six children were infected and two of those patients died.
Luckily we have vaccines that can prevent infections with the most common strains of this organism, Neisseria meningitidis.
But where this bacteria is most letha, most deadlyl is in Africa. There is something called a meningitis belt in Africa where thousands of infections occur every year. Currently, there is an outbreak of meningitis in Burkina Faso where 718 people have died since the first of the year, 80% are between the ages of 2-30.
What is especially problematic, the strain of bacteria that is causing at least half of the mortality associated with this disease is a newly identified strain, termed strain X. Because it has never been seen before, it is not included in any vaccine, antibiotics are all we have to prevent severe illness. Heath care workers are calling this an infection at epidemic levels. So far, over 5000 people have been treated for exposure to this organism.
In a just released report from the Pittsburg Tribune-Review , a VA hospital in Pennsylvania gave a Navy veteran the wrong type of blood plasma due to an error in sample handling. The hospital is saying it was underlying medical conditions that actually killed Kenneth Guthrie, not the inappropriate blood plasma.
What do we know regarding this incident? The patient received 6 units of type O plasma when he actually had type B blood.
Now, normally type O blood is considered the universal donor blood type, but that is for red blood cell transfusion, or only to be used in emergencies when correctly matched rare blood is not available. However, when large volumes of plasma are transfused, there are naturally occurring antibodies called isoagglutinins that are present in the blood/plasma. Isoagglutinins are made to intestinal bacterial epitopes, but for some reason crossreact to ABO antigens found on other blood types. In type O blood, there would be anti-A as well as anti-B isoagglutinins present. When O plasma is transfused, the anti-B antibodies can bind to the antigen on the surface of a patient’s ABO-type B blood cells and started lysing them via complement activation, in a type II hypersensitivity reaction.
Kenneth Guthrie received six units of isoagglutinins. And died within 12 hours of receiving this transfusion. Also, the article stated that:
An internal VA committee later concluded Guthrie suffered “an acute hemolytic reaction due to the transfusion of incompatible FFP,” or fresh frozen plasma, the report states.
That doesn’t sound like underlying medical conditions to me. Also, Mr. Guthrie died in June of ’07. The VA hospital is just now implementing an automatic bar coding system for patient samples to prevent human error. But only after the Pittsburg Tribune story was made public.
You know it is bad when even the New York Times is discussing antibiotic resistance. How bad is it? From this NYTs report, it appears that gram negative organisms are vying to replace MRSA (a gram positive bacteria) on the list of the biggest problems in the world of antibiotic resistance. One of the organisms discussed, Acinetobacter baumannii was the cause of many Gulf War infections. According to the report:
“In many respects it’s far worse than MRSA,” said Dr. Louis B. Rice, an infectious-disease specialist at the Louis Stokes Cleveland V.A. Medical Center and at Case Western Reserve University. “There are strains out there, and they are becoming more and more common, that are resistant to virtually every antibiotic we have.”
Also scary?
According to researchers at SUNY Downstate Medical Center, more than 20 percent of the Klebsiella infections in Brooklyn hospitals are now resistant to virtually all modern antibiotics.
OK, it wasn’t on their front page, but in their business section. Why? Maybe because big Pharma isn’t interested in making antibiotics that act on gram negative infections. Yet. Also, these gram negative infections are still predominately limited to hospitals. Unfortunately, it appears they may be a primary cause of nosocomial infections which kill 99,000 individuals every year. And remember when MRSA was first discovered, it too was limited to hospitals. It managed to find its way out of the hospitals, when will these?
And the final note? According to one doctor quoted in the article:
For Gram-positives we need better drugs; for Gram-negatives we need any drugs
On my note, we need to be more responsible when using antibiotics. Period.
Tags: Acinetobacter baumannii, Antibiotic resistance, Gram negative, Klebsiella, MRSA
USA Today is reporting a large outbreak of a Norovirus on the Celebrity Cruise ship Mercury. 419 passengers became ill out of 1800 passengers (23%). The symptoms for the norovirus are vomiting and diarrhea for 1-2 days.
Disinfecting an area that has been contaminated with norovirus has been notoriously hard to do. In one study, enhanced hygiene techniques were used (handwashing, surface cleaning, using disposable paper towels, and using separate toilets for sick and well persons) reduced secondary cases by almost 85%. However, that still leaves some individuals becoming ill after extreme measures. And on a cruise ship, how many ill individuals would it take to infect the closed and confined quarters of a cruise ship? Hmmm.
On that note, this same ship is scheduled to leave port next week.
The outbreak isn’t expected to have an impact on next week’s cruise on the ship, Martinez says. “We have already begun extra cleaning, in an abundance of caution,” she says. “We do not expect a delay at turnaround.”
Bon voyage cruisers! And remember: