Modern Age of Microbiology PDF

Modern Age of Microbiology Some Understanding of Immunity 1880- Pasteur conducted study on Fowl cholera. - Fowl cholera is a contagious bacterial disease of birds, caused by Pasteurella multocida.  He started with a very virulent strain of the disease. Each time he would inject a new bird wit...

Modern Age of Microbiology Some Understanding of Immunity 1880- Pasteur conducted study on Fowl cholera. - Fowl cholera is a contagious bacterial disease of birds, caused by Pasteurella multocida.  He started with a very virulent strain of the disease. Each time he would inject a new bird with the organism it would die.  Over time he noticed that the birds began to live in spite of the injections with the disease.  Then he noticed that when he injected them again with a fresh new strain, they still didn’t get sick.  Pasteur concluded that the strain that had been grown in the lab for a long period of time was still able to cause an immune response. Thus the animals became immune to the disease.  Pasteur creates the first laboratory-produced vaccine: The vaccine for fowl cholera in chickens.  Definitions: ❑ Virulent: able to cause disease ❑ Avirulent: unable to cause disease  Modern Microbiology Microbiology is now divided into several separate fields of study. ❑ Bacteriology: study of bacteria. ▪ 1997- new bacterium discovered by Heide Schulz Thiomargarita namibiensis- consumes H2S ▪ All organisms going through reclassification due to genomic studies. ▪ Classified according to: ▪ visual characteristics (features) ▪ metabolic characteristics  Modern Microbiology ❑ Mycology: study of fungi. ▪ Increase in fungal infections in California by Valley fever (Coccidioides immitis) ▪ Agostino Bassi - silkworm disease was caused by a fungus. ❑ Parasitology: study of parasites. ▪ protozoa and parasitic worms continually found. ❑ Immunology: study of the immune system ▪ Dates back to Edward Jenner (1796) ▪ Some vaccines developed since, but new vaccine research is rapidly growing due to ability to manipulate DNA. ▪ Eradication of Smallpox ▪ 1960 Interferons were discovered - are proteins that are part of your natural defenses. ▪ Biggest challenge is AIDS, still no known cure and no vaccine possibilities yet. ▪ Destroys immune system ❑ Virology: study of the viruses. ▪ Dmitri Ivanoski – reported that certain organism cause mosaic disease of Tobacco. ▪ Wendell Meredeth Stanley – (TMV) Tobacco mosaic virus - the first virus to be crystallized. ❖ OswaldAvery, Colin Mcleod, and Maclyn McCarty o Streptococcus pneumoniae o they determined that genes are contained in molecule of DNA. “transforming principle" ❖ George Beadle and Edward Tatum o Working on Bread mold (Neurospora crassa) o They stablish that a gene’s activity is related to the function of specific protein coded by that gene. Chemotherapy - It is a drug treatment that uses powerful chemicals to kill fast-growing cells in your body.  Sulfa drugs were the first type of medicine prescribed for infections.  Bacteriostatic  Antibiotics were discovered first in 1928 - Penicillin  Alexander Fleming (Penicillium notatum).  “mold must be killing the bacteria”  Many antibiotics that we use today are made by other organisms.  discovered lysozyme, an enzyme with weak antibacterial properties that inhibited bacterial growth Molecular Biology Combination of biochemistry, cell biology, and genetics to explain cell function at the molecular level. Genome sequencing  Laureate Linus Pauling Propose that gene sequences could provide a means of: ✓ understanding possible evolutionary relationships and processes, ✓ establishing taxonomic categories that more closely reflect these relationships, and ✓ identifying the existence of mi- crobes that have never been cultured in a laboratory. Recombinant DNA technology commonly called Genetic Engineering  Genome- is the total genetic information of an organism.  Recombinant DNA – is the DNA composed of genes from more that one organism. Geneticists manipulate genes in microbes, plant, and animals for practical use Ex: Gene Therapy A process that involves inserting a missing gene or repairing defective one in human cells. 3 main goals of gene manipulation  To manipulate undesirable phenotypic traits in humans, animals, plants, and microbes. ▪ Inserted genes from microbes to plant (resistant to pest and freezing). ▪ In humans, cured some children born with fatal & previously untreatable genetic disorder called Severe Combined Immunodeficiency Disease (SCID) 3 main goals of gene manipulation  Tocombine beneficial traits of two or more organism to create valuable new organisms. ▪ Ex. Lab animal that mimic human susceptibility to HIV.  To create organisms that synthesize products that humans need. ▪ Ex: vaccines, antibiotics, hormones etc. The Tools of Recombinant DNA technology ❖ Mutagens ❖ Reverse transcriptase ❖ Synthetic nucleic acids ❖ Restriction enzymes ❖ Vectors  World health Infectious Diseases Affecting health Science ▪ Increase number of drugs resistant strains including Nosocomial and Community Acquired microorganism ▪ MRSA – Methicillin Resistant Staphylococcus aureus ▪ VRE – Vancomycin Resistant Enterococcus ▪ VRSA – Vancomycin Resistant Staphylococcus aureus ▪ MDR-TB – Multidrug Resistant Tuberculosis END