"Microbiology in a nutshell"
Microbiology in a Nutshell Yes, you will need to know this Microbes Ever wonder why Robin Williams is hirsute, while Patrick Stewart is follecularly challenged? Well, the answer is in their DNA- Viruses • • • • Microscopic (can’t see with the naked eye) nonliving particle Invades and reproduces inside a host. Contains DNA or RNA The red spots are the AIDS virus, they are surrounding other body cells. Virus Multiplication • Active – Become sick within hours or days • Hidden – Illness can be delayed for weeks, months, or years – Triggered by environment? Bacteria • Microscopic • Prokaryotes (means they don’t have a nucleus) • Living • Contains DNA Shapes of bacteria • • • • Spherical Rodlike Spiralshaped They can also be in chains – Spherical chain Bacteria Multiplication • Sexual reproduction – Two parents – Conjugation (transfer of genetic material through bridge) • Asexual reproduction – Binary Fission-Simply splitting in two Growth in Action More on Growth • Rapid, as fast as once every 20 minutes • Continues until they run out of the basics – Food – Air – Space Parasites • Organisms that live on or in a host and cause harm. • Examples: Viruses, Bacteria, and tapeworms. • Can a bacteria be a host? How many can there be? • These bubble-headed creatures are called bacteriophages, viruses that target bacteria. The head holds DNA and the tail acts as a needle attaching to a specific site on the bacterial cell wall, the virus squirts DNA through the tail into the bacterium. Ouch! They are among the smallest of organisms. You could fit about 680,000 of these creatures on the head of a pin. What can you do? • • • • Get Vaccines Personal Hygiene Use Disinfectants Lines of Defense – Skin – Mucus barriers – Immune System Defenses cont. . This is a human macrophage, found in your blood that wards off infection. It is homing in on a chain of nasty Streptococcus bacteria. Hitching a ride aboard the macrophage is a sphere-shaped lymphocyte. Both macrophage and lymphocyte can be found near the site of an infection, and the two act in concert to help eliminate it. The deadliest pandemic in history was the 1918 influenza epidemic, the Spanish Flu. By the time the "Spanish lady" departed, 22 million people had died of the mysterious killer. Positively identifying the 1918 flu strain is made more difficult by the fact that the flu virus is capable of very rapid mutations Personal example • A doctor stationed at Camp Devens, a military base just west of Boston, writes to a friend, and fellow physician, of the conditions to be found there as influenza was making its presence felt. Vaccines Existing flu shots are 70 percent to 90 percent effective at preventing flu in healthy young people • 50 percent effective in the elderly, (And even if the vaccines don't prevent the flu, they do tend to reduce symptoms and serious complications). High Risk Groups • aged 65 and older • with chronic diseases affecting the heart, lung or kidneys • with diabetes, immunosuppression, or severe anemia • people in contact with doctors, nurses and nursing-home staff Prevention • "The current U.S. plan in the event of a pandemic is to vaccinate virtually the entire population," says epidemiologist Nancy Arden. • Despite its advantages, less than 60 percent of the high-risk population gets the flu shot each year.