Things people do that increase the rate at which antibiotic resistant bacteria become more common Agricultural Use Over-use; misuse Patient non-compliance

About 5 percent of patients who enter acute-care hospitals acquire infections from their hospitalization, and the incidence of drug-resistant strains of the most common of these so-called nosocomial infections (e.g., Staphylococcus aureus) is on the rise.

Resistance genes can be transferred from one species to another. Plasmids can accumulate genes for resistance to many antibiotics.

1854: John Snow

In one particular neighborhood, the intersection of Cambridge Street and Broad Street, the concentration of cholera cases was so great that the number of deaths reached over 500 in 10 days

Snow investigated the situation and concluded that the cause was centered around the Broad Street pump. His solution? Have the pump handle removed

Cholera Transmission: water-borne The bacterium that causes cholera is Vibrio cholerae The disease can spread in situations of massive overcrowding without adequate safe drinking water and sanitation. Cholera can almost always be treated with oral rehydration therapy

In 1991, inadequate sanitation brought on an epidemic of cholera in South America for the first time in almost a century.

Examples of Viruses that Cause Diseases DNA viruses examples: the Herpes viruses Poxviruses Parvovirus RNA viruses examples: Rhinoviruses Retroviruses Flu viruses

Arbovirus Exantheme Enterovirus Respiratory viruses How are Viruses Classified?

This is an Alphavirus, one of the best known model systems among enveloped viruses. The RNA genome (red) is packaged into a nucleocapsid (orange for the capsid proteins), which is surrounded by a lipid bilayer (green) with transmembrane spike proteins (blue).

Measles. Worldwide, almost 1 million children die of measles each year. In the United States, after a long decline, the number of measles cases started to rise in the late 1980s when there was a drop in the number of children being vaccinated against the disease.

Measles Pathogen: An exantheme virus Same as distemper in dogs High fever, runny nose, red eyes, spots, sensitivity to light

Herpes Viruses

Herpes Simplex--Type 1 causes fever blisters and red eye no cure; usually not life threatening but, can lead to blindness; rarely causes brain inflammation; stress causes reoccurrence

Herpes Simplex--Type 2 Herpes Zoster Epstein-Barr Viruses (associated with mononucleosis) (associated with mononucleosis)

Pathogen Herpes-zoster Transmission Person-to-person Symptoms Chicken Pox and Shingles Prevention VaccineChickenPox