Describe
the endosymbiont theory of the evolution of eukaryotic organisms.
What is a pathogen?
A disease causing organism
Parasite- an organism that feeds on another living organism
Host - an organism that has a parasite.
Who invented the microscope? Leeuwenhoek
Who introduced the germ theory of disease? Pasteur
Who developed a plan to determine whether a particular “germ”
caused a specific disease? Koch
In a cell culture, a mound of bacteria is called a colony
In lab, we grow bacterial cultures in agar
Rod shaped bacteria are called _____bacilli___________
Sphere shaped bacteria are called _______cocci_________
Spiral shaped bacteria are called ______spirilla___________
Chains of cocci are called ____Streptococci____________
Clusters of cocci are called _____Staphylococci________________
Gram-positive bacteria stain _____purple__________ (color)
Gram-negative bacteria stain _____pink__________ (color)
Bacteria typically reproduce by ______binary fission
___________________
When two bacteria bind together and exchange transfer genetic material, it is called ____conjugation_______
A long structure that moves bacteria along is called a _______flagella_________
Why is a virus not considered to be alive?
It is not cellular. It cannot grow, reproduce, etc. without invading a
host cell.
Do antibiotics such as penicillin kill viruses?
No
Why does the
Sanitation,
flushing toilets, healthcare
Virus – infective particle, contains DNA or RNA
Covered with a capsid. May or may not have an envelope
Bacteriophage – virus that infects a bacteria
Bacteriphages
can make bacteria be more virulent
Propionibacterium acnes – acne
Impetigo -
caused by Staphyococcus areus or Streptococcus pyogenes
Cellulitis - caused by Staphyococcus areus or Streptococcus pyogenes or other infectious agents
Why does one Strep or Staph cause a mild case of impetigo and another organism of the same species can cause necrotizing fascilitis or “flesh eating disease”
Bacteriophages
encode for extreme virulence.
Patient
resistance to bacteria varies.
Why is an open or compound fracture
considered to be an immediate emergency? It can
become infected and get gangrene.
Chicken pox – caused by Human Herpes 3, varicella, a herpes virus, DNA
How do people get shingles?
The herpes that causes
shingles becomes dormant, but continues to live in the nerves of infected people. Stress causes the virus to become active.
Should children with chicken pox or other febrile disease be given
aspirin for fever? Why or why not? No,
aspirin in febrile children is associated with Reye’s Syndrome which can cause
encephalopathy and death.
Smallpox – caused by
the variola virus, an Orthopox virus
Prevention
– vaccine developed by Edward Jenner, from cowpox virus.
Measles – Paramyxovirus, can cause death
Rubella – causes severe birth defects in children infected in utero
Roseola – human herpes virus 6
Warts – papillomas
Ringworm - caused by a fungus
Pinkeye - conjunctivitis, may be viral, bacterial, or even protozoal, or animal
Common causes – Staphylococcus, Streptoccus, gonorrhea, Chlamydia, contact lenses
Rhinitis
What is it? Common cold
Why is there no vaccine? To many causes
Otitis Media
What is it? Middle ear infection
Why do children get it? Small Eustachian tubes
Pharyngitis: Sore throat
Scarlet fever – caused by bacteriophage infected strep, high fatality rate
Rheumatic fever - strep, immunological reaction with heart muscle
Diptheria – Corynebacterium diphtheria, forms membrane over throat that obstructs breathing
Pertussis – Bordetella pertussis, severe coughing than can cause death
Respiratory Syncytial Virus (RSV) –highly contagious respiratory virus, serious in newborns
Influenza – virus of respiratory system, can cause death, there is a vaccine
Swine flu – mutated from pig flu and killed people
Avian influenza (bird flu) – can infect and kill humans, must get it from bird, not contagious to from person to person
Tuberculosis –Mycobacterium tuberculosis, causes nodules in lungs, common in crowded conditions
Pneumonia – infection of lung
Things that lead to gum or tooth disease: poor nutrition, poor dental hygiene, high sugar diets, genetics
Mumps – Paramyxovirus, infection of salivary glands, especially parotids (parotitis)
Diarrhea:
Salmonella – (gram negative) chicken, eggs, reptiles, causes severe diarrhea
Typhoid fever- (gram negative) a severe species of salmonella, often in contaminated food or water
Shigella - (gram negative)causes severe bloody diarrhea (dysentery), produces a Shiga toxin, infects humans and apes, cruise ships
E. coli 0157:H7 (gram negative) severe diarrhea, kidney failure, seizures, stroke, death, comes from cow feces
Clostridium difficile – (gram positive) – normal flora in small amounts, overgrows and can cause severe disease when normal bacteria are killed off with antibiotics
Vibrio cholera – high mortality rate, often in epidemics in times of tragedy such as floods or war
Food poisoning- comes from toxins in ingested food
Giardia – protozoan, in animal and human carriers, often in contaminated water, streams
Hepatitis:
Hepatitis A-from contaminated foods, can be transmitted sexually
Hepatitis B- bloodborne, causes cirrhosis, can cause cancer, from blood, shared needles, needle sticks, sexual transmission. Vaccine is available.
Hepatitis C – bloodborne
Enterobius vermicularis – pinworms, live in large intestines, lay eggs on anus, kid scratches itchy anus, infects others from fingers
Trichinosis- causes muscle and joint damage, intestinal damage. Comes from eating rare bear, pork, dog, cat, or rats.
Urinary Tract Infections
–
Cystitis- sudden onset, pain, burning, urgency to urinate, can have blood
Pyelonephritis- infection of kidney
Urinary tract infections are usually caused by anything that transmits bacteria from the anus to the urethra. More common in females due to shorter urethra. Sexual activity, improper wiping techniques, or anything else that can transfer bacteria can lead to cystitis. Young girls should be told to always wipe from front to back and to urinate after sexual activity.