News » Chapter 17 Treatment and Prevention of Disease

A measleslike virus is responsible for the recent Dolphin die-off

Contributed by paustian on Sep 06, 2013 - 09:21 AM

Over 300 dolphins have washed up along the eastern coast of the U.S. since July 1st of this year. Scientists at the NOAA declared a Unusual Mortality Event, allowing them to use fund and perform an extensive investigation of the cause. A combination of classic of tissue investigation along with molecular techniques  that assayed for the presence of the virus, revealed the cause to be a Morbillivirus. The Morbillivirus family includes viruses such as measles, that infects humans, and distemper, that infects dogs. The dolphin virus poses no threat to humans.



A similar outbreak in 1987 killed more 700 dolphins. This recent outbreak was probably caused by a large enough population of young, susceptible dolphins being being to now sustain another epidemic of the disease. The virus is likely to continue to cause illness until the population of susceptible individuals declines, either by them gaining immunity to the virus or dying.



MRSA: Farming up trouble

Contributed by rsingh26 on Aug 09, 2013 - 05:22 PM

MRSA (methicillin-resistant Staphylococcus aureus) has distressed hospitals for more than forty years and also has been infecting individuals outside of healthcare settings since 1995. MRSA is responsible for 94,000 infections and 18,000 deaths every year in the United States. Because MRSA initially appeared on a US farm, many scientists, such as epidemiologist Tara Smith, have dedicated their research in determining whether farms’ use of antibiotics is contributing to the increased drug-resistant bacterial infections in humans. 



Predatory Bacteria and Human Health

Contributed by sciencesmith on Aug 08, 2013 - 07:16 PM

There are many example strains of pathogenic bacteria that have developed resistant to drugs. The reduced effectiveness of antibiotic drugs for treating infections is increasingly a concern for doctors and patients alike. Pneumonia is caused by a microbial infection of the lungs, and if untreated it can be painful and fatal. Traditionally pneumonia is treated by using antibiotic drugs to combat the infecting microbes. However, Klebsiella pneumoniae is one example of a drug resistant bacteria that causes pneumonia when it infects the lungs. Treating such an infection is very difficult if antibiotics are not effective. Researchers are looking for alternatives to antibiotic drugs to combat pathogenic infections.



 



New Antibiotic Found That Attacks MRSA Found in Ocean Microbe

Contributed by lucas_suyang_pinoli on Aug 08, 2013 - 12:10 PM

Methicillin-resistance Staphylococcus aureus (MRSA) is a bacterium that generally causes difficult to treat infections in humans.  Beta-lactam antibiotics attack agents that contain the Beta-lactam ring, successfully inhibiting bacterial wall synthesis and eventually killing the bacterium. Bacteria then develop a resistance to the drug by synthesizing Beta-lactamase, an enzyme which attacks the Beta-lactam ring. Beta-lactam antibiotics include penicillins and cephalosporins. Patients that have open wounds or lower immune systems are especially prone to contracting MRSA infections.



Plant-based compound may prevent HIV infection

Contributed by eduardojpina on Aug 06, 2013 - 05:32 PM

HIV research have come a long way since the beginning of the epidemic with newer and newer treatments being discovered and administered. However, a classic drawback on novel medications is the virus's ability to develop newer drug resistance strains against the treatment. This is largely due to the virus's high genetic variability, fast replication cycle, and high rate of mutation.

New hope arises from an unlikely source, the soybean. New evidence from the George Mason University researchers suggests that a compound found in soybean may become an effective treatment in inhibiting HIV infection without creating resistance strains so commonly found in classic HIV treatments. Genistein, a compound found in soybeans and other plants, is a tyrosine kinase inhibitor. This compound works by blocking the communication system between the cell's exterior surface with the interior. On the cell's exterior surface are sensors that gather information of the cell's environment. These sensors will then communicate with the cell's interior portion. The cell will then use this information to create proteins or stop creating proteins, depending on the needs of the cell given the state of its environment.


Antibiotics Take Toll on Beneficial Microbes in Gut

Contributed by hmcarlson on Aug 06, 2013 - 02:28 PM

In the late 1800s a search for antibiotics began in accordance with the growing acceptance that bacteria and microbes have a causal effect on the human body leading to a variety of ailments. From this point in time onward there has been a pursuit for drugs to deter or kill this disease causing bacteria.  Antibiotics can be seen in use for serious life-threatening illness, such as pneumonia, kidney and heart infections, or after major operations to reduce the chances of infection, but also for non-serious ailments such as sore throat or ear infections.  With the wide range that such antibiotics can be utilized for there must be wonder of what exactly the effects, to the human body especially the microbiota in the intestinal tract, are due to the over prescription of antibiotics.  


Bacteria Communicate to Help Each Other Resist Antibiotics

Contributed by thewho521 on Aug 06, 2013 - 12:23 PM

As many know, antibiotics are at the front line of medical treatment when it comes to many deadly bacterial infections such as pneumonia, dysentery, and others.  Dr. Miguel Valvan and Omar Halfawy have showed that antibiotic resistance can come from more than just an acquired trait within the cell. They observed that large populations of antibiotic resistant strains share small molecule metabolites with other non-resistant cells.



Simply reducing antibiotic use doesn't guarantee a decrease in resistance among bacteria

Contributed by lzarling on Aug 02, 2013 - 02:17 PM

Antibiotic resistant bacteria emerge from improper and over usage of antibiotics. However, antibiotic resistant bacteria have some disadvantages of their own.  When not exposed to antibiotics, non-resistant bacteria are often selected for due to the fact that there is an energetic cost associated with being immune to antibiotics. Because of this, it is now desired to reduce antibiotic use in proper situations with the hope of decreasing resistance among bacteria. This is often successful. However, due to the vast complexity of these studies, the results are not easily interpreted. Patients are often taking a cocktail of antibiotics to fight disease and it is possible for there to be contact between hospitals and the community, resulting in the exchange of resistant bacteria. This makes the process increasingly difficult. Additionally, depending on which antibiotics are reduced in usage, the results can vary. For instance, in the case of Staphylococcus aureus, otherwise known as MRSA, a reduction in the use of penicillins does not result in decreased resistance because many strains of S. aureus are already resistant to penicillin.  On the other hand, a reduction in the use of clindamycin and methicillin lead to lessened antibiotic resistance.



Study finds biochemical role of crucial TonB protein in bacterial iron transport and pathogenesis

Contributed by lucas_suyang_pinoli on Jul 24, 2013 - 08:59 PM

The biochemical role of the protein, TonB, was relatively unknown for decades, but recent research has helped clear that up. TonB was noted to be especially important, as it is a pivotal factor in the membrane protein of Gram-negative bacteria—specifically aiding in the uptake of iron into the microorganism. The key in this discovery is finding it within the parameters of Gram-negative bacteria. Gram-negative bacteria, as opposed to Gram-positive bacteria, are typically considered the more virulent of the two types of bacteria because of a cell wall found only in Gram-negative bacteria that act as a physical barrier against antibiotics. Gram-negative bacteria cause a significant number of serious diseases and clinical conditions. In the spectrum of the medicinal aspect of microorganisms, Gram-negative bacteria are perceived as posing a threat to the progression of anti-biotics.



Antibiotic resistant bacteria chemically communicate resistance to less-resistant bacteria

Contributed by epnfrn on Jul 20, 2013 - 07:10 PM

A new study conducted by El-Halfawy and Valvano has demonstrated how resistance to antibiotics can be communicated to other less resistant bacteria through secreted chemicals. They investigated the mechanism of resistance to a bactericide, polymyxin-B (PmB), in resistant strains of Burkholderia cenocepacia, a species that causes severe infections in patients with cystic fibrosis.   



Creating a vaccine for malaria using chemically attenuated parasites

Contributed by rmrogan2 on Jul 19, 2013 - 07:10 PM

Malaria is a parasitic disease spread by mosquitoes that causes an estimated 1 million deaths per year.  Four different types of Plasmodium parasites can cause malaria and in many regions of the world these parasites have developed resistance to a variety of the medicines used to treat malaria.  It is believed that the development of a vaccine will be the most effective way to decrease the amount of deaths caused by this disease.  In the past, vaccine development for malaria focused on inducing antibodies that are able to recognize antigens found on the surface of the parasites.  However, this type of vaccine has so far been unsuccessful due to the numerous polymorphisms found in the proteins that make up the surface of the parasites,  These polymorphisms enable the parasites to evade the host's immune system.  In the past ten years, different methods have been used to research the effects of infecting rodents with low-density blood-stage infections of the Plasmodium parasites to induce immunity.



Novel Strategies for Safer Long-Term Antibiotic Usage

Contributed by kfbeach on Jul 19, 2013 - 07:06 PM

            Scientists at the Wyss Institute for Biologically Inspired Engineering at Harvard University have gained new insight into the dangers associated with long-term antibiotic usage.  The scientists, led by Jim Collins, Ph.D., have discovered the cause behind hazardous side effects resulting from long-term usage of antibiotic drugs and have proposed two solutions to prevent and reduce these negative effects. 



            Doctors have been prescribing antibiotics under the general assumption that the drugs harm only bacterial and not human cells.  Contrary to this belief, adverse effects such as tendonitis, hearing loss, diarrhea, and kidney dysfunction have all been reported with long-term use of antibiotics.  The research team at the Wyss Institute found that these side effects occur as a result of human cells suffering oxidative stress, causing damage to DNA, proteins, and lipids.  Collins proposed that the oxidative stress arose from production of chemically reactive oxygen molecules, those oxygen molecules being responsible for the damage occurring in the cells.



Novel chemistry for a new class of antibiotic

Contributed by lalever on Jul 12, 2013 - 07:37 PM

novel class of antibiotic being explored at the University of Adelaide has shown potential in the fight against bacterial antibiotic resistance.  Professor Andrew Abell and his colleagues have engineered antibiotic compounds that target a key metabolic enzyme, biotin protein ligase, instead of the cell membrane, which is a common target of some existing antibiotics.  By changing the target of the antibiotic, it is hoped that a broad range of antibiotic resistant bacteria will again be susceptible.   



Getting the floc out of here

Contributed by paustian on May 22, 2013 - 07:28 PM

Floc is a real work, even if your spell-checker flags it. In fact, it's a scientific word that describes those little particles of fluff that float in aquatic systems. These little specs floating in the water column have a sinister secret, they harbor antibiotic resistance. Drudge et. al from McMaster University tested four different sites, Hamilton Harbour, impacted by sewer overflow; Sunnyside Beach in Toronto, impacted by wastewater; a rural stream by light agricultural activities; and a remote lake in a natural preserve area in Algonquin Park looking for 54 different known antibiotic resistance genes. As one would expect, the more pollution in the water system, the more antibiotic resistance genes were found. This is yet another reason to keep aquatic environments clean.

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