"[Our philosopher] asserted that he knew the whole secret...[H]e surveyed the two celestial strangers from top to toe, and mantained to their faces that their persons, their worlds, their suns and their stars, were created solely for the use of man. At this assertion our two travelers let themselves fall against each other, seized with a fit of...inextinguishable laughter"
-- Voltaire (1752)
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Hello all. My name is Luu. This is a science blog, on a microscopic and astronomical scale (and a combination of both--extraterrestrials!). I'm biology student, pretty much in love with the universe.
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This is an electron microscope image that shows hairlike fibres of epoxy resin assembling around a polystyrene sphere about 2 microns in diameter.
The egg is surrounded by a glycoprotein coat called the zona pellucida which aids in trapping and binding the sperm. Two residual coronal cells from the ovarian follicle are attached to the zona pellucida. The egg is sitting on the point of a pin.
Bacteria, protozoa, and algae from a wild stream
Under a moderately-high magnification of 2500X, this digitally-colorized scanning electron micrograph (SEM) of an untreated water specimen extracted from a wild stream mainly used to control flooding during inclement weather, revealed the presence of unidentified organisms, which included bacteria, protozoa, and algae. In this particular view, a microorganism is featured, the exterior of which is covered by numerous projections imparting an appearance of a sea urchin. This microscopic “pin cushion” was teathered to its surroundings by a biofilm within which many bacteria, and amoeboid protozoa could be seen enmeshed as well.
Though many organisms found in untreated waters are harmless, there are many that are pathogenic to both humans and animals, including Giardia spp., free-living amebae, and E. coli just to name a few. During power outages, the functionality of treated water systems can be negatively affected, thereby, violating the patency of these closed systems. In these instances, advisories may be posted, encouraging inhabitants of these regions to boil their water tap water in order to kill off any pathogenic organisms that may have entered the system due to an intrasystemic drop in positive pressure.
Not only do water treatment plants remove such pathogenic organisms, but chemical that can be injurious to humans and animals are filtered from the water making it potable. Again, during power outages, or in the case of broken pipes, chemicals can contaminate tap water rendering it unsuitable to drink as well.
Photo Credit: Janice Haney Carr, CDC
Pseudomonas aeruginosa is a gram-negative, rod-shaped, asporogenous, and monoflagellated bacterium that has an incredible nutritional versatility. It is about 1-5 µm in length and about 0.5-1.0 µm in breadth and is an obligate aerobe, which means it requires oxygen and uses aerobic respiration as its choice of metabolism. Due to its capability to synthesize arginine, P. aeruginosa can also proliferate in anaerobic conditions. This, then, makes P. aeruginosa a very ubiquitous microorganism, for it has been found in environments such as soil, water, humans, animals, plants, sewage, and hospitals. In all oligotropic aquatic ecosystems, which contain high-dissolved oxygen content but low plant nutrients throughout, P.aeruginosa is the predominant inhabitant and this clearly makes it the most abundant organism on earth.
P.aeruginosa is an opportunistic human pathogen. It is “opportunistic” because it seldom infects healthy individuals. Instead, it often colonizes immunocompromised patients, like those with cystic fibrosis, cancer, or AIDS. It is such a potent pathogen that firstly, it attacks up two thirds of the critically-ill hospitalized patients, and this usually portends more invasive diseases. Secondly, P.aeruginosa is the leading etiology for Gram-negative bacteria at most medical centers, carrying a 40-60% mortality rate. Thirdly, it complicates 90% of cystic fibrosis deaths; and lastly, it is always listed as one of the top three most frequent Gram-negative pathogens and is linked to the worst visual diseases. Furthermore, P.aeruginosa is a very important soil bacterium that is capable of breaking down polycyclic aromatic hydrocarbons and making rhamnolipids, quinolones, hydrogen cyanide, phenazines, and lectins. It also exhibits intrinsic resistance to a lot of different types of chemotherapeutic agents and antibiotics, making it a very hard pathogen to eliminate.
www.microbeworld.org
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