Saturday, October 27, 2007

Viral Obesity!

There has been a growing concern over the population of obese adults and overweight children; this concern has especially grown in the United States. The general consensus as to why the belt size of the population has grown is that as the country’s economy improves, the quantity of food presented at the dinner table has increased dramatically, that along with improved technology has caused both children and adults to stay indoors sitting in front of the TV or computer instead of heading outdoors for fresh air and exercise.

The cause for obesity is not a secret. Most of people know obesity occurs because of the consumption of more calories than what is burn in a person’s daily activities! (However, what causes the imbalance between calorie consumption and calorie output differs from person to person, and possible factors can be due to genetics, physiological, environmental factors…etc.) Most of us also understand the health risk one must face if he or she is obese. These risks include: developing heart disease, stroke, diabetes, gout, cancer, gallbladder disease, sleep apnoea, and osteoarthritis.

Scientists have long understood that obesity is not only caused by eating more and exercising less (although it is the main factor in obesity); however, it’s not until recently have they discovered that a virus may be one of the other factors at play causing obesity. According to Dr. Atkinson, director of Obetech Richmond, Va., several studies have offered evidence that animals infected with human virus called Human Ad-36 experienced excess weight gain and fat storage and that the resulting weight gain could be transmitted from infected animals to uninfected animals. He also conducted his studies on humans. Atkinson screened 502 people of varying body weights (both obese and non-obese) for antibodies to Ad-36, and found that the antibodies were found in 30% of obese individuals and 11% of lean individuals. He also did his study on twins and found that within a pair of twins, the one that was screened antibody positive was “significantly heavier than their antibody negative co-twins.”

Moreover, a team at Louisiana’s Pennington Center conducted another experiment using stem cells from fatty tissues taken from liposuction patients and exposed these stem cells to Ad-36 and found that these exposed stem cells had changed into human fat cells after one week; however, the non exposed stem cells were not transformed. Dr. Magdalena Pasarcia, who led this research said: “We're not saying that a virus is the only cause of obesity, but this study provides stronger evidence that some obesity cases may involve viral infections.” Now, researchers are trying to produce a vaccine against Ad-36 (but this will take years to develop).

Although studies have proved that the virus can play a role in obesity, we cannot allow ourselves to live an unhealthy lifestyle. If a person has an unhealthy lifestyle and because of that lifestyle has developed diseases linked to obesity, there really is no point in blaming it on his or her genetic inheritance or viral infection. These studies did show that even with the viral infection, many people can live without being affect by the virus! This new discovery is not going to cure all obese patients overnight (and lower the risks of other disease that follows it.) It’s everyone’s responsibility to keep his or her own mental and physical health at the best shape possible. Eat right, think right and live healthy!

Monday, October 22, 2007

Flesh Eating Bacteria

Growing up in Shawnigan Lake, just north of Victoria, I lived down the street from an elementary school called Elsie Miles. When I was about six, a little boy who attended Elsie Miles contracted the flesh eating disease Necrotizing Fasciitis and had to have his leg amputated to stop it from spreading to other parts of his body. I was horrified that bacteria could spread so quickly and efficiently that amputation was the only option to save the boy.

According to the BC Health Files, Necrotizing Fasciitis is a rare and serious disease that can destroy skin and underlying tissues. This disease is able to spread through human tissue at a rate of 3 centimetres per hour, and can cause death within 18 hours. Necrotizing Fasciitis is caused by several kinds of bacteria, but most notably Streptococcus pyogenes. 5-15% of normal healthy people harbour S. pyogenes in their respiratory system. S. pyogenes is responsible for strep throat, scarlet fever, skin infections, and rheumatic fever, but causes Necrotizing Fasciitis when it is able to enter the layers of tissue that surround muscle (Fascia).

Streptococcus pyogenes possesses several virulence factors that make it very successful as a pathogen. S. pyogenes is able to colonize and rapidly multiply by using lipoteichoic acids and fibronectin-binding proteins to adhere to host cells. Its lipid membrane and capsule help it to go undetected by host immune systems and avoid macrophages and neutrophils. The lipid membrane contains antigens similar to those found in cardiac, skeletal, smooth muscle, heart valve, and neuronal tissues. This allows the bacteria to blend in and mimic the host cells. The capsule is composed of hyaluronic acid, which is found in human connective tissue. This also helps camouflage the bacteria from the host immune system.

Because of the evasive tactics employed by S. Pyogenes, as well as the rapid colonization and replication, people who have contracted Necrotizing Fasciitis often see a doctor when the disease is already in an advanced state. Antibiotics (penicillin) are effective against S. pyogenes, however if the patient has Necrotizing Fasciitis, blood supply to the infected tissue is cut off and antibiotics are not able to reach the site of infection. Surgery is almost always a necessity and amputation may be necessary in serious cases.

In the case of the little boy, it was lucky that the infection was able to be halted through amputation of the leg. It scares me to think what would have happened had the infection occurred in an area that was not able to be removed.


Image is courtesy of the Centers for Disease Control and Prevention image library.

Thursday, October 18, 2007

The end for superbugs

With our improved healthcare system and increased development of antibiotics, it’s not hard to think for a split second that we are safe from infectious bacteria! However, recent outbreaks of “superbugs” have proved otherwise.

There have been outbreaks of MRSA in the hospitals; this superbug has been found to be resistant to 15 to 30 different antibiotics. That means when it's detected, a doctor has only a very small number of compounds at hand that are able to kill it. Another superbug that is causing a stir is a strain of highly drug-resistant Streptococcus pneumoniae which causes acute ear infections in children. As these superbugs are discovered, other bacteria are continually becoming more and more antibiotic resistant.

When people are infected by bacteria, most people will turn to doctor prescribed antibiotics for help; however, antibiotics will manage to kill most of the bacteria cultures, but not all of them! The bacteria that survive the antibiotic treatments most likely would have had some resistance from the start, or that they would have acquired it through mutation or gene exchange with other bacteria. Those cells that survived now face reduced competition from antibiotic susceptible bacteria, and they will go on to proliferate, therefore becoming increasingly resistant to the drugs that we use. So here’s the question: if bacteria adapt and evolve so fast, is there a way to prevent these bugs from mutating into an even more drug resistant bacteria? Floyd E. Romesberg seems to have found the key (at least a start) to preventing bacteria from developing resistance.

To understand his research, first, you will have to know how bacteria mutation occurs. Durring the 1970s scientists discovered the “SOS response” that occurs in bacteria that take advantage of mutation as a form of self defense (chromosomal mutations). “When bacteria are under extreme stress, they try various means of fixing the damage as an initial step. Then they switch genes whose protein products precipitate a spate of mutations that occur 10,000 times as fast as those arising during normal cell replication. In essence, the cells undergo a quick identity change.” (Stix 82) Romesberg used E. coli in his experiment. He found that by using ciprofloxacin (an antibiotic), it triggers the clipping of a protein called LexA in E. coli, resulting in fast development in resistance. When he and the researchers created a strain of E. coli in which LexA could not be cleaved off, the SOS response didn’t materialize. The group of researchers has also gotten similar results for another antibiotic, rifampicin. As a result of his discoveries, Romesberg has been trying to generate a small molecule that could be administered orally along with antibiotics which would switch off the process of LexA cleavage. His work is only focused on fluoroquinolones (bacterialcidal drug that inhibit DNA replication and transcription of the targeted bacteria) because resistance to them only develops through the chromosomal mutations of bacteria. However, this is not enough, as mentioned before, resistance can also be acquired in bacteria though gene exchange from other species or within the same species.

Nevertheless, Romesberg and his teams’ discoveries and researches will provide us a better option to fight off drug resistant bacteria instead of constantly coming up with new antibiotics. It’s all about tackling the source of the problem. But just as a note, people should stop being so depended on drugs. Don’t always go to the doctor for antibiotics and let your own body produce immunity against the foreign invaders because although antibiotics can be a quick fix to the sickness, and can be used to help those with a weakened immune system to save many lives, drugs can also cause complications between the patient and the bacteria. Also keep in mind that the dose of antibiotic intake during a bacterial infection is not always the more the better!


This is the site where Romesbergs article can be purchased online, sorry I couldn’t find a PDF copy of the article:

However, here’s the magazine reference:

Stix, Gary. “An Antibiotic Resistance Fighter.” Scientific American April 2006: 81-83


Wednesday, October 17, 2007

MRSA, When Should Disclosure Be Required?!

Should hospital staff that test positive as carriers for MRSA be allowed to continue to work with seriously ill patients? I say NO! Why? Given all the guidelines for prevention, there are still outbreaks in the hospitals.

A hospital staff member that is a carrier of MRSA just needs to sneeze into their hand and turn a door knob to get the spreading started. Prevention, it is easy, but, it will take a few minutes of your time., click at this site for correct hand washing guidelines.

The BC Health Files states " do not need treatment and you should continue with your normal activities" and "You do not need to disclose to your workplace, school or daycare setting the fact that you carry MRSA. " What! If I had children, I would not place them in a daycare where any individual is a carrier of MRSA.

The BC Health Files states for hospital visits, "Important: If you may be a carrier of MRSA and are going to be admitted into hospital, it is very important for you to let hospital admitting staff know. Steps will be taken to protect other patients and hospital staff from MRSA infection." This should be the case in all institutions. At the hospital you need to protect those that are seriously ill-Yes.

What about in the community with the weak elderly, young children, or immunocompramised individuals. Do they not have the right to be protected like the Hospital Staff?

It IS important to let your employer, school, daycare...etc know if you are a carrier of MRSA.

BC HealthFile #73, September 2005.

Tuesday, October 16, 2007

Robert Koch's ironic discovery

Robert Koch's Original photos!

The reason I say IRONIC is because we all know about Robert Koch (or should) and his discovery of Koch's Postulates, but what we don’t know is that he was using some of the most virulent bacteria that live still today. You may remember Anthrax from the "Amerithrax" phase in September 2001, following the terrorist attack on the twin towers. Robert Koch was the first to isolate this capsule-forming and spore-forming gram-positive bacteria named Bacillus anthracis. If you remember the formation of Koch's postulates, you will recognize the process by witch he discovered the relationship between a causative bacteria and a disease. The first causative bacteria to prove this association therefore, was Bacillus anthracis! Also interesting is that Robert Koch discovered Bacillus anthracis's ability to form endospores in 1877, however, the severe toxic properties of the bacteria were not recognized until 1954. Do you think Koch knew the phenomenon of the bacteria he selected at the time? The part that I find fascinating is that they believed that, because of the potency of anthrax bacilli observed in the deceased animals, the cause of death was actually the effect of a suggested "log-jam" theory (referring to a block in the capillaries). The fascinating part is not the theory (although intriguing), the fascinating part is that Koch survived, because the dead body of a bacillus anthracis infected mammal is considered a very dangerous source of anthrax spores. At this point, Lister’s idea of Phenol was evident, however, we know that this period of experimentation had not allowed for the safety procedures of today’s standards to mature in light of sanitation. It seems amazing that Koch, or anyone working with him, did not develop any obvious symptoms of the deadly disease cause by the bacteria. This is why:

The "log-jam" theory failed upon proof that cells extracted from animals dying of anthrax infection were toxin-filled and that was the real cause of symptoms and death due to the anthrax disease. Upon observation of this consistently appearing toxin, it was confirmed that a diffusible exotoxin made the bacillus anthracis highly pathogenic! But that’s not it!!!! ..... Bacillus Anthracis also has the ability to form a clycocalyx made of poly-D-glutamate polypeptide. The capsule is a strong survival mechanism, protecting its self from phagocytosis as well as aiding in the initial stages of infection. The bacteria form a spore as well, making it resistant to heat (of up to 80 degrees), cold, and desiccation. The spore has been known to survive for decades, sprouting consequential growth at an opportune change of environment any ware across the globe. Bacillus anthracis is contacted in humans in three ways: Ingestion, by skin contact, or by inhalation. Skin contact infection gives rise to the Greek origin on the name “anthrax”, meaning coal, due to the distinctive black lesion an infection produces. Inhalation is the most fatal, often causing death if not treated promptly. Seeing as the most common way to contract the disease is by direct contact with infected animals or their carcasses, Koch must have been either very careful in his experiments or very lucky. In fact, Koch lived to be 66 years old, and died from a heart attack that seems to be unrelated to his study of disease.

Another notable fact that made Bacillus anthracis's "claim to fame" for previously oblivious microbiology students and people alike, was the anthrax panic in the United States in 2001. The strain of bacteria used in the letters was originally a warfare weapon for World War II (sick hey?) but is now being controlled within an estimated 15 labs throughout the United States. Two forms of anthrax were synthesized from the same bacterial Ames strain. The anthrax letters, addressed to different media stations in New York as well as to the senator, were contaminated with the cutaneous anthrax (the skin contact infection) and the more serious inhalation form of anthrax. Five people died of anthrax infections, 11 were in critical condition, and 22 people showed sever symptoms, but were treated efficiently.

Overall, I thought this was a pretty interesting bacteria. Let me know what you all think!
Sorry about my horrid spelling- I spell checked but I know Im not the best speller.

Saturday, October 13, 2007

Have you ever heard of natto?

Although there are some pathogenic one, some bacteria help our everyday life as we can see from this blog. We learned that bacteria is really important for the carbon, nitrogen and sulfur cycle in our life. For instance, without bacterias' help, we cannot use nitrogen since the nitrogen as a waste is too stable for us to use. And as everyone knows, bacteria are also used for various kinds of food which usually promote more health benefits for us.

Natto (fermented soy beans) is the Japanese traditional food which we Japanese people especially eat for a breakfast. There are differences about the origin of natto among some sources, but people started to eat long time ago. Originally, people stored soybeans in straws for preservation since Japanese people grew rice as a staple diet, and they got natto from them. How did the soybeans become natto? That is the job bacillus natto do! Bacillus natto live in straws, and they ferment soybeans, which leads to more healthy soybean food. By fermenting soybeans, it is also said that proteins are more easy to assimilate to our body compare to the non-fermented soybeans. Moreover, the well-known job bacillus natto does is the production of the enzyme called nattokinase. Natto contains a lot of nattokinase which lyses clotting in blood stream, and we can prevent incidence of thrombosis such as myocardial and cerebral infarction.

Natto is rich in source of vitamin K since it is made from soybeans. Vitamin K is pro-coagulants which is converted from vitamin K in a liver as a clotting factors. Therefore you have to pay attention since vitamin K is associated with some blood clotting activity, and especially people taking certain medicine (such as warfrin) have to attention the excess intake of natto. So don't take natto too much although it is highly nutritional. I believe moderate intake works best no matter how nutritious the food is.

It is hard to get natto here, but you can get it at some Japanese grocery stores. As a microbiology student, why don't you try one:)?


Monday, October 8, 2007

They are talking about us!!!

The Bayblab dudes are a very nice bunch. Interesting guys and interested in science and everything in between....and they are talking about us!!! Visit them here:

Tuesday, October 2, 2007

"Cleaning-Up": Pollution eating bacteria give new hope to future.

Bacteria are given a bad reputation for causing disease, infections, etc... Although this isn't entirely untrue, without bacteria many of the processes/cycles that occur in nature, and with in our bodies, would not take place without the aid of bacteria. Not only this, bacteria proves its efficiency by being able to "clean-up" our polluted planet. Although this is not an entirely new concept, it is now being researched and taken advantage more as our planet is becoming overwhelmingly polluted. There are many different bacteria that have the ability to break down toxic chemicals/pollutants, inflicted on the environment by its most ignorant inhabitants. Humans of course! Bacteria can be used to clean-up contamination of groundwater, soil, and ozone due to: the disposal/use of industrial solvents, gasoline, and other toxic chemicals, as well as oil spills and mining.
TCA1, Dehalococcoides Ethenogenes, Pseudomonas, Rhodococcus...These are just a few of the bacteria used individually, or in a consortium (mix of bacteria), to help rid the environment of some of the deadly toxins, and/or help degrade these toxins to less toxic compounds.
TCA1 breaks down trichloroethane (TCA) to a less toxic substance. TCA is a widely used industrial solvent found in products like degreaser and cleaner for metals, drycleaner and spot remover,propellant in aerosol cans, etc...It contaminates soil, ground water, and when airborne can erode the ozone layer.
Dehalococcoides Ethenogenes detoxifies carcinogenic chemicals such as perchloroethylene (PCE), and trichloroethylene (TCE), to a less toxic compound by dechloronation. PCE and TCE are found in industrial cleaners, and due to their disposal methods, are one of the worst organic groundwater pollutants.
Pseudomonas can work individually or in a consortium with Rhodococcus. Individually pseudomonoas degrade pre-dissolved benzene, toluene, and p-xylene (BTX). BTX is used for industrial purposes as well as for components in gasoline. In a consortium (mix of both along with other bacteria), the two bacteria help to degrade oil pollution due to oil spills. As much as 29 million gallons of petroleum enter the North American ocean waters each year alone; 85% of this is from land-based run-off, polluted rivers, airplanes, small boats and jet skis...all from human activities, while only 8% is actually from oil spills. Approximately another 47 million gallons comes naturally from the sea floor. The effects of oil pollution range from damage to marine life and the ocean environment, all the way to crippling a society based on profiting off of the ocean (tourism, fishing, etc...).
Along side oil pollution, pollution from mining also poses a serious threat to the environment (mainly by contamintating water from run-off); the most hazardous type in BC being Acid Mining. Acid mine drainage produces sulphuric acid, which leads to acid rain as well as acidic water unable to support life. Mining of all types can also lead to heavy metal contamination of water due to leaching (leaching is accelerated in the presence of acidity), contamination by chemicals (cyanide and sulphuric acid) used to separate minerals from ore, and contamination from sediment due to erosion of exposed earth. The problem may be partially solved. Newly discovered extremophile, "mineral-loving", bacteria can be used not only to help mine the metals, but also to clean up corrosive acid pollution byproducts of mining.
These are just a few examples of how bacteria can benefit our environment when it comes to ridding the planet of pollution. Although there are clear advantages to using bacteria in the case of pollution, whether it be pollution from the present or past, should we really continue to pollute the way we do and rely on other microorganisms to clean up after us? Or should we get to the root of the problem by trying to find more efficient, "environmentally friendly" ways to go about living? That way we can all enjoy a happier, healthier planet...and not just for the present, perhaps for the future too!


Picture is taken by me.