Antimicrobial Nanoparticles and MRSA

   by  EMSL "Zinc Oxide Particles"

A study done last year shows that certain nanoparticles can kill bacteria, even MRSA and other resistant strains. The nanoparticles are made with zinc oxide (ZnO) and titanium dioxide (TiO2). The researchers believe one of the ways these resistant species are so hard to control is their ability to form biofilms. Biofilms are large aggregates of bacteria that produce a matrix. The matrix protects some of the bacteria by not allowing antibiotics to come in to contact with the bacterial cells. The study focuses on the effectiveness of nanoparticles on the bacterial biofilms of MRSA.

Several isolates of MRSA that were shown to produce biofilms were cultured and allowed to aggregate. Commercially produced TiO2 and ZnO nanoparticles were introduced and the effects were measured. The particles had much greater inhibitory effects than all the antibiotics tested with it. Even low doses were better than most antibiotics, and some doses even prevented biofilms from forming. The results show that nanoparticles can be valuable tools to combat resistant bacterial strains. Using the particles to coat medical devices where biofilms readily form, like catheters, may prevent the formation of biofilms. Other possibilities for drugs or use with antibiotics should be researched further.

Antimicrobial Activity of Zinc and Titanium Nanoparticles against Biofilm Producing MRSA

Ants and Disease Transmission

   by  tarotastic 

Entomology and Biology professor David Hughes from Penn State was given the lead to find out if ants can teach us about the spread of disease in certain environments, such as large communal groups and offices. The National Science Foundation and the National Institutes of Health granted Dr. Hughes and his team a $1.8 million grant under the Ecology and Evolution of Infectious Diseases research initiative. The initiative "supports efforts to understand the underlying ecological and biological mechanisms that govern relationships between human-induced environmental changes and the emergence and transmission of infectious diseases."

The researchers will introduce various agents to ants and track the transmission. By varying the colony size and complexity, they hope to produce a mathematical model to expain the spread of diseases in populations that can eventually be used to predict transmission routes of human pathogens and help manage outbreaks. The team believes that ants can provide a reliable interactive community which to base the model on. Ants can be manipulated and colony size and structure can easily be changed to fit the goals of the researchers, and they're behavior is similar to other social groups.

A positive side effect of the study is an in-depth look at ant colony interactions. The social structures and methods of carrying out tasks could lead to a better understanding of how colonies react to insecticides that could be used to create more effective means of controlling pest ant species. The mathematical model of transmission could also be applied to livestock and agricultural diseases, leading to better prevention strategies and healthier animals and crops.

Penn State Study
Ecology and Evolution of Infectious Diseases Initiative

Infections From Cats

This weekend some friends finally got me to watch the BBC show "Sherlock". I know it's in its 3rd season, but I'm usually behind on things like this. Anyways, I've made my way through the 1st season, and its pretty good, even if some of the lab tests he performs are wrong or impossible, but that's another topic. In the 3rd (or last) episode, a woman dies from what seems to be an infection, but they are unable to figure out how she was infected. Watson visits her home and believes it was cat scratch. I'm not going to give away any more, but this got me thinking about cats. My family has had our share of cats, and along with that cat scratches. So what are some things you can get from your overly playful cat?

Cat scratch fever (Bartonellosis) is a bacterial infection caused by Bartonella henselae. It is the most common bacterial disease acquired from cats. The bacteria are commonly found in cats and don't usually cause a disease until it enters into the bloodstream. Fleas can also transmit the bacteria. Kittens are the most prone to harboring the bacteria and causing an infection in people or spreading it to other cats. Cats can also carry Salmonella and can infect through a scratch.

Cats may also have dirt in the claws, which can have a lot of bacteria found in soil that are pathogenic. The genus Clostridium lives in the soil and can cause tetanus and botulism. Bacillus can cause serious infections, including anthrax. Listeria and Camplybactor may be found and can also be transmitted via cat scratches.

This is not a comprehensive list, but just some common infections that can be passed from cats to humans.

Cornell Veterinary College
Soil-Related Bacterial Infections

UPDATE: Chikungunya Virus

Over the last week four more cases of Chikungunya virus have been reported in Alabama, along with the Huntsville case last week. One of those cases was in Birmingham. So far, all the people infected were travelers to parts of the Caribbean and no cases of infection from Alabama mosquitoes have been reported. However, the disease can cause relatively mild symptoms that may seem like allergies and a bad week of arthritis, which may prompt some people to stay at home instead of going to the doctor, so the exact number of actual cases is unknown.

There is still worry that the virus will spread to mosquitoes in the Southeast and an outbreak will occur. The CDC recommends following mosquito bite prevention guidelines, which can be found on their website and in the previous post. The CDC also urges anyone who has a fever and joint pain to see a doctor. There is no treatment and symptoms go away in about a week, but it is important that clinicians correctly identify cases of the virus so the infection patterns and numbers can be used to gather information and monitor its spread.

Certain Caribbean regions have been assigned Precaution Level 1 because of Chikungunya virus outbreaks. Anyone traveling to the Caribbean or South America should look up the region on the CDC Traveler's Page, which has information on current outbreaks and how to best prepare for travel to those regions.

CDC Mosquito Bite Prevention Guidelines

• Use air conditioning or window/door screens to keep mosquitoes outside. If you are not able to protect yourself from mosquitoes inside your home or hotel, sleep under a mosquito bed net.
• Help reduce the number of mosquitoes outside your home or hotel room by emptying standing water from containers such as flowerpots or buckets.
• When weather permits, wear long-sleeved shirts and long pants.
• Use insect repellents.
• Repellents containing DEET, picaridin, IR3535, and oil of lemon eucalyptus and para-menthane-diol products provide long lasting protection.
• If you use both sunscreen and insect repellent, apply the sunscreen first and then the repellent. 
• Do not spray repellent on the skin under your clothing.
• Treat clothing with permethrin or purchase permethrin-treated clothing.
• Always follow the label instructions when using insect repellent or sunscreen.

AL.com 4 More Virus Cases
CDC Chikungunya Virus
CDC Traveler's Page