HLTB16H3 Lecture Notes - Lecture 9: Typhoid Fever, Susceptible Individual, Microbiological Culture
Document Summary
Major infectious diseases of the 19th and 20th centuries; smallpox, cholera, tb, typhoid. Major scientific discoveries; infectious diseases are caused by specific microorganisms. Major public health achievements; purification of drinking water, proper disposal of sewage and garbage, milk pasteurization and immunization. Bacteria; fatty membrane containing ring of dna and cellular machinery, obtain energy from sugars, proteins, fats; can live and multiple outside host. Viruses; smallest infectious disease agents; thin protein coating around small piece of genetic material; require energy from host cells; cannot replicate outside host cell. Parasites; similar to human cells; can have a single cell or many cells; may or may not need host to replicate. Koch s postulates- rules to prove that specific organisms cause specific diseases. Organism must be present in every case of disease. Organism must be able to be isolated and grown in pure culture. Organism must, when inoculated into a susceptible individual, cause that specific disease.
