BACTERIA AS AN ART

Biophysicists are growing Petri dishes of different species of bacteria in order to develop new antibiotics. The bacteria are subjected to different temperatures and have limited food sources inside the dish. Despite these conditions, most colonies tend to communicate and reproduce. Their growth results in unique patterns of varying colors--a sort of "bacteria painting." Researchers are hoping to learn more about the strategies the bacteria use to thrive, in order to find weaknesses that new drugs could exploit.

There was a time when doctors thought antibiotics could cure all. It's a different story today as drug-resistant bacteria emerge in places like hospitals and schools. To keep up with changes in bacterial behavior, scientists are fighting bacteria using an artistic approach. Biophysicist Herbert Levine's Petri dishes look like an exhibit at a modern art museum. His beautiful images are actually made from bacteria similar to the ones that cause deadly diseases. Dr. Levine uses bacteria in Petri dishes in his quest to discover the next super drug. He's fighting a new generation of bacterial infections that includes MRSA, a flesh-eating disease resistant to antibiotics. Dr. Levine and his team have gone back to the basics of biology. They have created bacteria patterns by changing the temperature and limiting the food sources inside Petri dishes. Despite harsh conditions, the colonies find ways to communicate and reproduce. Through Dr. Levine's work, scientists have learned bacteria are very resourceful. They enclose themselves in areas antibiotics can't find. They also soak up antibiotics to keep the rest of their colony safe and transform themselves into new strains that are less sensitive to the drugs. Along the way, scientists turned the study of bacteria into an art form. Dr. Levine and his colleague, Eshel Ben-Jacob, use the patterns to create computer models. One day those models could be the basis for new medicines that fight all types of bacteria.

WHAT IS MRSA: MRSA is a common cause of skin infections; it can also cause pneumonia, ear infections and sinusitis. MRSA bacteria are sometimes dubbed 'superbugs' because they are highly resistant to common antibiotics like penicillin, making infections difficult to treat effectively. Bacteria are highly adaptive, and over time they naturally develop resistance, protecting them from incoming germs (and antibiotics) and making them harder to kill. If MRSA enters the body through the skin, it can cause irritating skin infections, but if it enters the lungs or bloodstream, it can cause serious blood infections, pneumonia, even death. MRSA infection rates in the US have been increasing since 1970, largely because surveillance programs to monitor its spread are not effective. Other countries, such as the Netherlands, Sweden and Denmark have all but eliminated MRSA from their hospitals through such surveillance programs, which focus on screening patients for MRSA at admission and isolating any carriers.

DRUG RESISTANCE: Bacteria are highly adaptive, and over time they naturally develop resistance, protecting them from incoming germs (and antibiotics), which makes them more difficult to kill. If someone has strep throat, for example, repeated exposure to penicillin and amoxicillin can result in a throat full of bacteria that can shield strep germs from the older drugs. The surviving bacteria then reproduce more and become more dominant. Sometimes parents discontinue antibiotic medication prematurely when they or their children begin to feel better, so the strep germ isn't entirely killed off, leading to much more severe infections requiring the use of even stronger drugs later on. This can also happen with many other infections inside the body and on the skin.

For Downloading Some more interesting Bacterial Patterns and Information Please visit:

http://star.tau.ac.il/~eshel/gallery.html

E. coli - Why is it a Master and Model of GENETIC EFFICIENCY
The bacterium Escherichia coli, one of the best-studied single-celled organisms around, is a master of industrial efficiency. This bacterium can be thought of as a factory with just one product: itself. It exists to make copies of itself, and its business plan is to make them at the lowest possible cost, with the greatest possible efficiency.

A bacterium like E. coli can be thought of as a self replicating factory, where inventory synthesis, degradation, and management is concerted according to a well-defined set of rules encoded in the organism’s genome. Since the organism’s survival depends on this set of rules, these rules were most likely optimized by evolution. Therefore, by writing down these rules, what could one learn about Escherichia coli? Scientists examined E. coli growing in the simplest imaginable environment, one constant in space and time and rich in resources, and attempted to identify the rules that relate the genome to the cell composition and self-replication time. With more than 4,400 genes, a full-scale model would be prohibitively complicated, and therefore they "coarse-grained" E. coli by lumping together genes and proteins of similar function. They used this model to examine measurements of strains with reduced copy number of ribosomal-RNA genes, and also to show that increasing this copy number overcrowds the cell with ribosomes and proteins. As a result, there appears to be an optimum copy number with respect to the wild-type genome, in agreement with observation. They hope that this model will improve and further challenge our understanding of bacterial physiology, also in more complicated environments.

Efficiency, in the case of a bacterium, can be defined by the energy and resources it uses to maintain its plant and produce new cells, versus the time it expends on the task. Dr. Tsvi Tlusty and research student Arbel Tadmor of the Physics of Complex Systems Department developed a mathematical model for evaluating the efficiency of these microscopic production plants. Their model, which recently appeared in the online journal PLoS Computational Biology, uses only five remarkably simple equations to check the efficiency of these complex factory systems.
The equations look at two components of the protein production process: ribosomes – the machinery in which proteins are produced – and RNA polymerase – an enzyme that copies the genetic code for protein production onto strands of messenger RNA for further translation into proteins. RNA polymerase is thus a sort of work ‘supervisor’ that keeps protein production running smoothly, checks the specs and sets the pace.

The first equation assesses the production rate of the ribosomes themselves; the second the protein output of the ribosomes; the third the production of RNA polymerase.
The last two equations deal with how the cell assigns the available ribosomes and polymerases to the various tasks of creating other proteins, more ribosomes or more polymerases. The theoretical model was tested in real bacteria. Do bacteria ‘weigh’ the costs of constructing and maintaining their protein production machinery against the gains to be had from being able to produce more proteins in less time? What happens when a critical piece of equipment is in short supply, say a main ribosome protein? Tlusty and Tadmor found that their model was able to accurately predict how an E. coli would change its production strategy to maximize efficiency following disruptions in the work flow caused by experimental changes to genes with important cellular functions. What’s the optimum? The model predicts that a bacterium, for instance, should have seven genes for ribosome production. It turns out that that’s exactly the number an average E. coli cell has. Bacteria having five or nine get a much lower efficiency rating. Evolution, in other words, is a master efficiency expert for living factories, meeting any challenges that arise as production conditions change.

For a detailed account download the following original research paper:
http://www.weizmann.ac.il/complex/tlusty/papers/PLoSCompBio2008.pdf

Fungi and Bacteria in Ventilation Systems
Fungi growing in ventilation systems may contaminate indoor environments and cause a variety of problems. Some fungi can cause lung infections. Many fungi can cause allergic reactions in susceptible people and respiratory irritation in non-allergic people.Inhalation of fungal spores by highly susceptible people can have fatal consequences. Some environmental bacteria can grow in ventilation systems, but these are raely a threat to healthy people. They can, however, be a nosocomial problem. Low levels of airborne fungi can be a primary or contributing cause of Sick Building Syndrome (SBS) and poor Indoor Air Quality (IAQ). The photomicrograph at the right shows lung tissue infected with a growing mycelium of aspergillus. Fungi differ significantly, in certain respects, from most other airborne pathogens, such as bacteria, viruses, and protozoa. Fungi do not cause secondary contagious infections; only the person inhaling the fungi is at risk. Fungi can exist outdoors and enter the building through the air intakes. No other respiratory pathogens can exist outdoors - viruses and bacteria are carried and transmitted indoors by human or animal hosts, with anthrax being the one exception. Fungi are normally harmless and non-parasitic. Fungal infections inevitably result from fungi being in the wrong place, often as the result of poor cleanliness or improper design of ventilation system components.
Fungi are actually plants that contain no chlorophyll -- see this chart.

The true fungi are the Eumycetes. Some of the fungi, the mushrooms, yeasts and some of the molds are extremely beneficial to us. They assist the production of cheese, antibiotics, yogurt, wine and beer. Some fungi, like the blights, can cause extensive crop damage. Dutch Elm disease is, in fact, a fungus. In buildings, the ones that cause problems when they get into the wrong place are usually certain of the ascomycetes.
Airborne Pathogenic Fungi
Only certain fungi can produce infections, and only a few of these have been noted to travel via the airborne route, or become entrained in the airflow of intake ducts. The following chart list those fungi which are of primary concern:

Fungi from Outdoors
Fungi produce spores, in much the same way as bacteria do, and this enables them to survive harsh conditions while they travel or lie dormant. Spores are usually what enter the building air intakes and what can travel through the ventilation airstream. Fungal spores are smaller than fungal cells and can vary in size from 1 micron to 100 microns. A well-maintained HEPA filter should be capable of intercepting the vast majority of fungal spores. At the right is an image of a colony of Candida albicans that has produced a number of large and small spores.
Fungi are ubiquitous in the outdoors, but occur in high concentrations only in hot Southern climates, especially during dry spells. Florida, Louisiana, Texas, New Mexico and southern California often experience high seasonal mold spore levels. Generally, when the ground dries after a period of moisture, the winds can overturn the top layers of soil and disperse large quantities of mold spores. These can be carried aloft into urban areas, where they are drawn into air intakes and building ventilation systems. The photo at left shows the long growing branches of mycelium that are characteristic of Nocardia asteroides, from a sputum sample of an infected patient. Nocardia are bacteria called actinomycetes, which greatly resemble fungi in characteristics, and they also produce spores.
Even though the problem is more common in southern states, it only takes the right conditions for microscopic quantities of fungi to gain a foothold in a ventilation system. This situation has occurred across the US, regardless of climate. Many, if not most, cases of poor IAQ and SBS can be tied directly to the occurrence of mold spores either in the ventilation ducts, or in the walls of buildings. Sometimes, fungi are merely a contributing factor when the ventilation is inadequate -- normal levels of airborne fungi are not removed from the building air.
Dealing with Fungi in Ventilation Systems
Filtration provides the primary defense against fungal spores entering a building ventilation system. Pre-filters can be effective against most fungi, even when in the spore form. If a higher degree of protection is required, HEPA filters can be very effective, provided they are tightly installed, and well maintained. Fungus can grow on HEPA filters as well as other ventilation components and, if unchecked, can actually contribute to the problem. The image at right shows a layer of actinomyces mycelium growing on a surface.
Fungus or fungal spores from the outdoors can be dealt with easily, as described above. If, however, the fungus is already growing inside the building or ventilation system, the problem becomes somewhat more difficult. Fungi require moisture for growth. The source of the moisture must be identified and then controlled.
Cooling coils, drains pans, and water pans for humidifiers are likely locations for fungal growth, especially when there is standing water. These must be treated as necessary with proper disinfectants. Some systems provide built-in UVGI lights for continuous disinfection. These components should be disassembled and cleaned with a strong disinfectant, such as chlorine, when fungal or bacterial growth is found. Clogged drains are often a cause for standing water.
Condensation on ductwork or other components is another likely source of moisture. The ductwork must be inspected for fungal growth and cleaned with a disinfectant. The cause of the condensation must be identified. Often, it results from inadequate insulation, or leakage into, or out of, the ductwork. Sometimes return air can leak into the supply air duct and result in localized condensation. Sometimes the insulation itself can absorb and hold moisture, resulting in fungus growth that may then directly or indirectly produce contamination of the building air. Smoke tests, or airflow measurements, and/or pressure tests can determine duct leakage.

In the absence of water they may reduce to spore form, which makes them even more subject to air entrainment. Therefore, a cycle of condensation and dehydration may exacerbate a fungal dispersion problem. In this case, the problem might be perplexing to isolate -- sometimes the duct and components will appear dry, while cases of respiratory irritation or infection may occur in irregular cycles that could ultimately depend on humidity variations. Every situation can be unique and must be studied carefully.
Air Sampling and Testing
Sampling of airborne microorganisms can be inconclusive. There are no absolute standards, and decisions on whether a building has a fungus problem or not are often made arbitrarily. Methods of collection can give divergent results and are therefore heavily subject to interpretation. Swabbing a sample from a duct or an exhaust grille will yield some concentration of fungal or bacterial cells, but doesn't exactly correlate with airborne concentrations.
Measuring airborne concentrations can likewise produce results that depend on interpretation. Often, the testing agencies will not identify the specific microorganisms, but will merely state that colonies were formed, or that there is a potential contamination problem. Most fungi are unique and have distinctive characteristics. The photomicrograph at right shows a colony of actinomyces, in which the radiating rays of the mycelium are clearly visible around the central granule.
Any studies contracted to be performed, such as on schools or office buildings, should be required both to state the types of microorganisms discovered, their probable airborne concentrations, and how these compare with standards or typical concentrations in normal, or "healthy," buildings.

For further information please follow the following Link:
http://www.cancerfungus.com/pdf/fungi-nexus.pdf
http://www.naima.org/pages/resources/library/pdf/RP032.PDF
http://www.library.ca.gov/crb/01/notes/v8n1.pdf