Lecture 9

Question 1

Chemotherapy

Answer 1

The use of drugs to treat disease

Question 2

Antimicrobial drugs

Answer 2

Interfere with the growth of microbes within a host

Question 3

Antibiotic

Answer 3

Substance produced by a microbe that in small amounts inhibits another microbe

Question 4

Selective toxicity

Answer 4

A drug that kills harmful microbes without damaging a host

Question 5

Sulfa drugs

Answer 5

Competitive inhibitors
Early antimicrobial drugs,
Sulfonamides = interfere with microbial folic acid synthesis

Question 6

Bacitracin

Answer 6

Topical application against gram +

Question 7

Vancomycin

Answer 7

Glycopeptide , important “last line” against antibiotic resistant S. Aureus (causes hallucinations)

Question 8

Antibiotic Resistance

Answer 8

1. Enzymatic destruction of drug
2. Prevention of penetration of drug, cell receptor is blocked
3. Alteration of drug’s target site
4. Rapid ejection of the drug, bacteria pumps out waste AND the antibiotic
   Resistance genes are often on plasmids or transposons

Question 9

Human effects of antibiotic resistance

Answer 9

Misuse of antibiotics leads to mutations. Misuse includes using antibiotics for common cold or other inappropriate condition.
Use of antibiotics in animal feed (BIG CAUSE)

Question 10

Synergism

Answer 10

When the effect of two drugs together is greater than the effect of either alone

Question 11

Antagonism

Answer 11

When the effect of two drugs together is less than the effect of either alone

Question 12

Antimicrobial Peptides

Answer 12

Broad spectrum antibiotics from plants and animals include Squalamine (Shark), Protegrin (pig), Magainin (frog)

Question 13

Antisense Agents

Answer 13

Complementary DNA or peptide nucleic acids that bind to a pathogen’s virulence genes and prevent transcription

Question 14

Laryngitis

Answer 14

Inflammation of the larynx
Caused by S. Pneumoniae, S. Pyogenes

Question 15

Pharyngitis

Answer 15

Inflammation of the pharynx , throat

Question 16

Tonsillitis

Answer 16

Inflammation of the tonsils
Caused by S. pneumoniae, S. Pyogenes

Question 17

Sinusitis

Answer 17

Inflammation of the sinuses

Question 18

Epiglotitis

Answer 18

Inflammation of the epiglottis
Caused by H. Influenzae

Question 19

Rhinitis

Answer 19

Inflammation of the nasal passages

Question 20

Otitis media

Answer 20

Inflammation of the middle ear (Part of upper respiratory because of eustaChian/ auditory tubes connection to the mouth

Question 21

Upper respiratory microbiota

Answer 21

Many of the normal upper respiratory microbiota may include pathogens

Question 22

Streptococcal pharyngitis (strep throat)

Answer 22

Caused by streptococcus pyogenes
Resistant to phagocytosis
Streptokinases Lyse clots
Streptolysins are cytotoxic
Diagnosis by indirect agglutination

Question 23

Scarlet fever

Answer 23

Caused by Streptococcus pyogenes
Pharyngitis
Erythrogenic toxin produced by lysogenized S. Pyogenes

Question 24

Diphtheria

Answer 24

Caused by Corynebacterium diphtheriae (gram-positive rod)
Diphtheria membrane of fibrin, dead tissue, and bacteria
Diphtheria toxin produced by lysogenized C. Diphtheriae
Prevented by DTaP and Td vaccine (diphtheria toxoid)
Cutaneous diphtheria = infected skin wound leads to slow healing ulcer

Question 25

Otitis media

Answer 25

Most cases caused by S. Pneumoniae or H. influenzae Treated with broad-spectrum antibiotics Incidence of S. Pneumoniae infection reduced by vaccine

Question 26

Common Cold

Answer 26

Viral infection of the upper respiratory system Rhinoviruses (50%) 2 to 3 days Coronaviruses (15-20%) 5 to 10 days , attached to ACE receptors Rhinoviruses attached to ICAN-1 on nasal mucosa

Question 27

Bronchitis

Answer 27

Inflammation of the windpipe, trachea, and bronchi

Question 28

Bronchialitis

Answer 28

Inflammation of the bronchi

Question 29

Pneumonia

Answer 29

inflammation of the alveoli where fluid replaces airspace

Question 30

Pertussis (whooping cough)

Answer 30

Caused by Bordetella pertussis, gram - coccobaccilus , capsule Tracheal cytotoxin of cell wall damages ciliated cells Pertussis toxin Prevented by DTaP vaccine (acellular pertussis cell fragments)

Question 31

Tuberculosis

Answer 31

Mycobacterium tuberculosis, acid-fast rod. Transmitted from human to human M. Bovis accounts for < 1% of US cases, transmitted from cattle to humans M. Adium-intracellulare , complex infects people with late stage HIV infection Diagnosis = tuberculin skin test , + test is current or previous infection Followed by X-ray or CT

Question 32

Pneumococcal Pneumonia

Answer 32

Caused by Streptococcus Pneumoniae , gram + encapsulated diplococci Diagnosis by culturing bacteria Penicillin is drug of choice

Question 33

Haemophilus Influenzae pneumonia

Answer 33

Haemophilus = blood loving Caused by gram - coccobacillus Alcoholism , poor nutrition, cancer, or diabetes are predisposing factors If diagnosed early, 2nd gen cephalosporins are very effective

Question 34

Mycoplasma Pneumonia

Answer 34

Pleomorphic, wall-less bacteria Also called primary atypical pneumonia and walking pneumonia Common in children and young adults Diagnosed by PCR or by IgM antibodies

Question 35

Legionellosis

Answer 35

Legionella pneumophila: gram - rod Found in water Transmitted by inhaling aerosols Tx: erythromycin Incident was at a legionnaires meeting, they showered with this river water that was contaminated

Question 36

Psittacosis (ornithosis)

Answer 36

Chlamydia psittaci: gram - intracellular bacterium Transmitted by inhaling elementary bodies from bird dropping to humans Reorganizes into reticulate bodies after being phagocytized Tx: tetracycline Psittacots genus = parrots Ornithosis = comes from birds It is a chlamydia = obligate inteacellular parasite

Question 37

Q fever

Answer 37

Coxiella burnetti , gram - rod. Highly resistant to high temp, osmotic pressure, and UV. Makes a small cell variant that looks like a sport, has a large active cell and a small resistant cell

Question 38

Viral Pneumonia

Answer 38

Viral pneumonia is a complication of influenza, measles, or chickenpox Viral etiology suspected if no cause determined Respiratory Syncytial Virus (RSV) -common in infants, 4500 deaths annually -causes cell fusion (syncytium) in cell culture -symptom is coughing Tx: Ribavirin

Question 39

Influenza

Answer 39

Symptoms: Chills, fever, headache, muscle aches (NO INTESTINAL SYMPTOMS) 1% mortality due to secondary bacterial infections Tx: Amantadine , weakens immune system, interferes with healing processes Vaccine for high risk individuals Typical duration = 7-10 days Flu is more contagious than covid!!

Question 40

Hemagglutinin (H)

Answer 40

Spike proteins used for attachment to host cells for the influenza virus

Question 41

Neuraminidase (N)

Answer 41

Spike proteins used to release influenza virus from cell

Question 42

Antigenic shift

Answer 42

Changes in H and N spikes Probably due to genetic recombination between different strains infecting the same cell

Question 43

Antigenic drift

Answer 43

Mutations in genes encoding H or N spikes May involve only 1 amino acid Allows virus to avoid mucosal IgA antibodies

Question 44

Histoplasmosis

Answer 44

Histoplasma capsulatum, dimorphic fungus (grows like a yeast cell in body) Transient infection in a non immunocompromised individual Transmitted by airborne conidia from soil Tx: amphotericin B

Question 45

Pneumocystis Pneumonia

Answer 45

Pneumocystis jiroveci (P. Carinii) found in healthy human lungs Pneumonia occurs in newly infected infant and immunosuppressed individuals Tx: timethoprim-sulfamethoxazole Used to be very common killer in AIDS patients