Lecture 11

Question 1

Klebsielle Pneumoniae 225

Answer 1

-Example given at start of class of bacteria that is resistant to EVERYTHING except imipenem and fluoroquinolones

Question 2

Bacteria

Answer 2

• Bacteriology
• Prokaryotic
• Single cell organisms
• Most antimicrobials target bacteria
• Ex: strep, staph, pneumonia

Question 3

Fungi

Answer 3

• Mycology
• Eukaryotic Cells
• Single or multi-cell organisms
• Chemotherapy is more limits
• Ex: Candida, athlete’s foot, aspergillus

Question 4

Virus

Answer 4

-Virology
-Non-cellular
-Obligate, intracellular pathogen
-Infectious
-Anti-viral development challenging
Ex: Chicken pox, measles, mumps, shingles

Question 5

Parasites

Answer 5

• Parasitology
• Tape worms
• Trichomoras
• Dracunules medinensis

Question 6

Prions

Answer 6

-Non-cellular
-Pathogen protein
-Driven by amount of glycosylation, possibly
Animals: Mad Cow Disease, Chronic Wasting Disease
Humans: Kuru, Fatal Familial Insomnia

Question 7

Infectious Disease

Answer 7

• Noncommunicable Disease

- Nosocomial Infections

Question 8

Noncommunicable Diseases

Answer 8

• Caused by microbiota
• E. Coli or microbiota in improper places (deep tissues, mouth biota in heart, etc.)
• Food poisoning due to pre-formed toxins or botulism in adults are examples
• Transmitted by common source - Legionnarie’s disease from HVAC or Pseudomonas in water
• Diseases from pathogens in environment can also be a source (fungal spores, tetanus, etc.)

Question 9

Spread Methods (2)

Answer 9

• Vertical

- Horizontal

Question 10

Vertical Spread of Infectious Disease

Answer 10

• Mother-to-child
• Transplacental (child birth)
• Breast milk
• Rubella, AIDS, Herpes

Question 11

Horizontal Spread of Infectious Disease

Answer 11

• Other routes

- Saliva, skin to skin, fecal-oral, vector transmitted, zoonoses

Question 12

Direct Spread

Answer 12

-Moves without help from one person to another, close contact is required, travels within a meter of distance
-Saliva/respiratory droplets are means or transport
Ex: common cold or influenza

Question 13

Skin-to-Skin Contact Spread Example

Answer 13

MRSA (occurs in athletes commonly)

Question 14

Blood-borne Spread Examples

Answer 14

Hepatitis A & B, AIDS

-Requires inoculation of blood/blood products

Question 15

Fecal-Oral Spread

Answer 15

• Intestinal pathogens spread via this method
• Increased risk with children in daycare, holding children, and even shaking hands
• E. Coli, Shigella, Campylobacter, Salmonella

Question 16

Indirect - Respiratory Infection

Answer 16

-Air particle over distance greater than a meter
-Fomites - inanimate objects that spread disease
Ex: Flu or cold

Question 17

Indirect - Intestinal Infection Paths

Answer 17

-Contaminated water, food, and fomites

Question 18

Indirect - Blood-borne Infection Paths

Answer 18

-Needle sticks and scalpel cuts tend to allow for pathogens to infect

Question 19

Biological Vectors

Answer 19

• Indirect infection via anthropods
• Ex: Malaria, Lyme Disease, Rocky Mountain Spotted Fever, Plague
• Passed via mosquitos, ticks, lice, etc.

Question 20

Animal Infections

Answer 20

• Zoonoses
• Diseases transmitted from animals to humans
• Direct contact - rabies, anthrax, etc.
• Indirect contact - Lyme Disease, plague
• Travel: Vertebrate»_space; Vector»_space; Human

Question 21

Patterns of Incidence (4)

Answer 21

1. Sporadic
2. Endemic
3. Epidemic
4. Pandemic

Question 22

Sporadic

Answer 22

Observed only occasionally and without geographic concentration

Question 23

Endemic

Answer 23

Low, constant levels (smoldering infection)

Question 24

Epidemic

Answer 24

Higher levels of infection in a short time in a geographic location

Question 25

Pandemic

Answer 25

Widespread (possibly worldwide) infection with high attack rates

Question 26

Nosocomial Infections

Answer 26

- Health-care associated - NOT present at time of admission - Develops during hospitalization (5-15% patients) - Can occur from contact with health care professionals, contaminated equipment, ventilators, IV, catheters, spread of normal flora, or surgery - High mortality rate - people infected are already sick and have weakened immune defenses. Most of these infections are resistant to drugs though they rarely infect health individuals

Question 27

Primary Pathogen

Answer 27

Disease causing pathogen in health, strong individuals

Question 28

Opportunistic Pathogen

Answer 28

Disease causing pathogen in compromised host

Question 29

Pseudomonas Aerginosa

Answer 29

- Can be part of normal microbiota - Serious and life-threatening infections in burn patients, those on respirators, eye infections with contacts, and outer ear infections

Question 30

Are opportunistic pathogens avirulent?

Answer 30

Far from it, usually contain a multitude of virulence factors.

Question 31

Infectious Dose

Answer 31

Amount of pathogen needed to infect 50% of patients. Usually measured for diarrheal pathogens

Question 32

Newly Discovered Infections

Answer 32

Hantavirus, HIV, Ebola, West Nile Virus, SARS, and MERS

Question 33

Evolving/Re-emerging Threats

Answer 33

Community-acquired MRSA, Pan-resistant bacteria, E. Cola O157H7

Question 34

Superbugs Problems

Answer 34

- Pan-resistant bacteria is on the rise - Pipeline of new antibiotic development is dwindling - Resistance to new drugs is rapid

Question 35

How to Avoid Antibiotic Resistant Pathogens?

Answer 35

- Slow evolution of resistance - Appropriate use of antibodies - Drug combinations - Attack virulence factors - Hospital Infection Control

Question 36

Miama Superbug Outbreak

Answer 36

- Admission file: XDR bacteria - Only sensitive to colistin and gentamicin - Overlooked and ignored - 9 more patients came in over 3 months with identical cases - Overall impact: 5 died, 2 survived with kidney failure, 3 survived without kidney failure