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H5 avian flu virus. About 17 million birds were slaughtered in the Fraser Valley in February 2004 following an outbreak of the H7N3 strain of the disease, but it was a different strain from the deadly H5N1 version linked to nearly 250 deaths and other illnesses in Southeast Asia, China, Russia and Europe. Animal Cell Complex Many specialized organelles Nucleus surrounded by membrane Bacteria Tiny single celled organisms Differ from plant and animal cells in that they have no nuclear membrane Some organelles Viruses Much smaller than bacterium Protein coat and genetic material (DNA or RNA) Bacterial Shapes Cocci spheres Monococcus Single sphere Diplococcus Live in pairs Streptococcus Chains of spheres Staphlococcus Grape-like clusters Streptococcus Staphlococcus Bacterial Shapes Bacilli Rod shaped Streptobacillus ? Staphlobacillus ? Bacterial Shapes Spirillium Spiral or cork-screw shaped Bacterial Reproduction Bacteria contain the genetic blueprint (DNA) and all the tools (ribosomes, proteins, etc.) they need to reproduce themselves Reproduce through binary fission May exchange genetic material Bacterial Reproduction E. coli bacteria, found in the gut can divide every 20 minutes - this could yield 72 generations per day -that's 40 with 21 zeros after it bacteria. Bacteria Named by Shape Pathogenic Bacteria Clostridium botulinum Botulism is the result of an exotoxin produced by this anaerobe Staphlococcus - Grape-like clusters ―Boils‖ Pathogenic Bacteria Staphylococci Part of normal fauna of face and nose skin infections, boils and pimples but a virulent strain may cause death Streptococcus - Chains of spheres ―Strep Throat‖ Pathogenic Bacteria Streptococci strep throat, scarlet fever (caused by the bodies immune reaction) rheumatic heart disease Necrotizing fasciitis Pathogenic Bacteria Treponema pallidum syphilis spirochaete Pathogenic Bacteria Nesseria gonorrhoeae diplococcus gonorrhoea, very resistant strains to antibiotics have recently evolved Pathogenic Bacteria E. coli Normal inhabitant of the gut of many animals and birds Indicator of fecal contamination of water and food Escherichia coli O157:H7 (more than 70,000 a year infected in USA) http://www.sciencenews.org/20010804/bob12.asp Plaque Tooth decay is the destruction of the outer surface, or enamel, of a tooth. It is caused by acid buildup from plaque bacteria, which dissolve the minerals in the enamel and create cavities. Antibiotics Bacterial infection can be directly treated through the use of antibiotics. The action of these drugs is varied but many interfere with bacterial reproduction. Remember E. coli with 72 generations per day Penicillin – the first antibiotic 1928 Alexander Fleming was growing staphylococci bacteria that he had isolated from wounds on agar plates. Became contaminated Penicillin identified the fungus as Penicillium notatum Was unable to stabilize penicillin 1940 Ernst Chain isolated and purified penicillin and human trials began Penicillin kills bacteria by interfering with the ability to synthesize cell wall. Penicillin Before the introduction of penicillin many people died from bacterial infections How many times have you taken an antibiotic? It probably saved your life. Antibiotics produced by Bacteria they are produced by some bacteria to prevent other bacteria from growing near them and using up their food Tetracycline Streptomycin Erythromycin How do antibiotics interfere with bacterial reproduction? Biofilms Biofilms — snotty sheets of goo made by bacterial colonies — may be the secret superpower of the microbial world. When bacteria are deeply encased in a biofilm, they don't grow or reproduce. Since antibiotics work by disrupting those same activities, such bacteria are nearly invincible. Biofilms might be behind the tenacity of chronic ear infections and even tuberculosis. Ancient Life The cyanobacteria or "blue-green algae," have left a fossil record that extends far back into the Precambrian - the oldest cyanobacteria-like fossils known are nearly 3.5 billion years old, among the oldest fossils currently known. short chain of cyanobacterial cells, from the Bitter Springs Chert of northern Australia (about 1 billion years old). living cyanobacterium Cyanobacteria Many oil deposits are attributed to the activity of cyanobacteria The oxygen atmosphere that we depend on was generated by numerous cyanobacteria The chloroplast with which plants make food for themselves is actually a cyanobacterium living within the plant's cells Women have a greater range of different types of bacteria on the palms of their hands than men, US research from the University of Colorado at Boulder suggests. http://news.bbc.co.uk/2/hi/health/7705608.stm Tuesday, 4 November 2008 Using powerful gene sequencing techniques, researchers found a typical hand had roughly 150 different species of bacteria living on it. The study detected and identified more than 4,700 different bacteria species across 102 human hands in the study. However, only five species were shared among all 51 participants. • Even the right and left palms of the same individual shared an average of only 17% of the same bacteria types. • On average, women had 50% more bacterial species on their hands than men. • The higher bacterial diversity on women's hands may be due to the fact that men tend to have more acidic skin, which provides a more harsh living environment for the microscopic bugs. • Dr Fierer said the study also found hand washing had little impact on the diversity of bacteria found on an individual's hands. • While some groups of bacteria were less abundant following hand washing, others were more abundant. • However, the researchers said that washing with anti-bacterial cleansers was still an effective way to minimise the risk of disease, as it seemed particularly to target harmful bugs. Most are likely to be neutral, just living there without doing any harm or good. It is thought that having such flora on our hands is probably beneficial, because the bacteria occupy niches which are then unavailable to pathogens. Prions Prions are rather ill-defined infectious agents believed to consist of a single type of protein molecule with no nucleic acid component. These agents are associated with Kuru and Creutzfeldt-Jakob disease in humans scrapie in sheep bovine spongiform encephalopathy (BSE) in cattle. The diseases are not caused by a bacterium—or a virus—or anything containing nucleic acid. They appear to be caused by nothing more than a misfolded protein, called a prion (proteinaceous infectious only; 2). In addition, prions can apparently cross species barriers. BSE is unlike many other food-borne pathogens in that it cannot be killed simply by cooking the infected meat. Milk and milk products from cows are not believed to pose any risk for transmitting the BSE agent. BSE In 1986, BSE (bovine spongiform encephalopathy or ―mad cow disease‖), a prion disease of cattle was described in England. The symptoms in affected cattle rapidly changed behavior inability to stand reduced sensation. When the epidemic peaked in 1993, an estimated 1.2 million animals were possibly infected, and the meat of about 730,000 BSE- infected cows had entered the human food chain Exports of beef from the United Kingdom were halted, and entire herds of cattle were destroyed to prevent the spread of the disease. The economic cost was huge. Bovine Spongiform Encephalopathy It was on September 10, 2001, that mad cow disease began a crisis in the North American beef industry. Japan reported its first case of bovine spongiform encephalopathy. People in Japan stopped eating beef! Impact on Canada Canada has close to 13.5 million cows and calves. About 5.7 million (or 42 per cent) are in Alberta. Canada's total beef exports amount to $2.2 billion annually, and have risen sharply in recent years. Since 1991, beef exports have risen from 100,000 tonnes to about 500,000 tonnes. Growth in exports has been greatest to Japan, South Korea and Mexico. Alberta's share of total beef exports is 39 per cent (worth about $860 million a year). Kuru The disease was the result of the practice of ritualistic cannibalism among the Fore,people of New Guinea in which relatives prepared and consumed the tissues (including brain) of deceased family members. Creutzfeldt-Jakob Disease First, the disease can occur sporadically, i.e. without apparent cause. Second, the disease can be inherited. 10 – 15 % of cases Third, the disease can be transmitted through infection Symptoms of CJD The initial stage of the disease can be subtle with ambiguous symptoms of insomnia, depression, confusion, personality and behavioral changes, problems with memory, coordination and sight. Symptoms of CJD As the disease advances, the patient experiences a rapidly, progressive dementia involuntary and irregular jerking movements Problems with language, and sight, muscular weakness, and coordination Symptoms of CJD In the final stage of the disease, the patient loses all mental and physical functions. The patient may lapse into a coma and usually dies from an infection like pneumonia precipitated by the bedridden, unconscious state. Treatment of CJS At the present time, there is no known effective treatment to arrest or cure CJD. The disease is inevitably fatal. The only treatments available for CJD patients focus on easing their symptoms and discomfort.
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