Chapter 20 (Microbiology)

Practice Questions

Do Gram-negative bacilli form spores?

No, Gram-negative bacilli do not typically form spores, as they are primarily non-spore forming bacteria.

Where can Gram-negative bacilli be found?

Water, soil, animals, and humans

What is lipopolysaccharide (LPS)?

A surface molecule in Gram-negative bacilli that acts as an endotoxin and can make people sick

What kind of pathogens are Pseudomonas? (Think of; Aerobic Gram-Negative Bacilli)

Opportunistic pathogens; attack those already sick

What kind of pathogens are Francisella? (Think of; Aerobic Gram-Negative Bacilli)

Zoonotic pathogens; transmitted between animals and humansW

What kind of pathogens are Bordetella and Legionella? (Think of; Aerobic Gram-Negative Bacilli)

Human Pathogens; primarily infects humans

Where does P. aeruginosa live and survive?

In water, soil, and harsh conditions like soaps and hospital equipment

Who does P. aeruginosa commonly infect?

Burn patients, cancer patients, and people with cystic fibrosis

What does P. aeruginosa smell like and produce?

Smells like grapes; produces greenish-blue pus

What is genera are included here? (Think of; Gram-Negative Aerobic Rods)

Acinetobacter, Francisella, Stenotrophomonas, Bordetella

Common Traits of these rods? (Think of; Gram-Negative Aerobic Rods)

Motile, Oxidase postive, Obligate aerobes, do not ferment sugars

Where is A. baumanii often found?

Hospitals

Why is A. baumanii dangerous?

Its very drug-resistant and infects wounds, lungs, and blood

Where does Stenotrophomonas Maltophilia form and where does it live?

Forms biofilms; found in soaps and machines in hospitals

What can Stenotrophomonas Maltophilia infect?

Lungs, blood, and brain

What disease does it cause? (Francisella Tularensis)

Tularemia (rabbit fever)

How is Francisella Tularensis spread?

Through rabbits, soil, water, or insect bites

Can Francisella Tularensis be used as a bioweapon?

Yes, its dangerous but rare

What disease does it cause? (Bordetella Pertussis)

Whooping cough (pertussis)

How is Bordetella Pertussis transmitted?

Through respiratory droplets (coughing/sneezing)

What does the DTaP vaccine protect against?

Pertussis (among others)N

Name two virulence factors of B. pertussis

Toxins that destroy ciliated cells, and receptors for epithelial cells

Where is Legionella found? (Legionella Pneumophila)

Water sources; hot tubes, plumbing, and cooling towers

Who is most at risk? (Legionella Pneumophila)

Elderly males over 50

What are two disease caused by Legionella Pneumophila?

Legionnaires' disease and Pontiac fever.

What are the common characteristics for the Enterobacteriaceae Family?

Non-spore forming, ferment glucose, facultative anaerobes, catalase postive, oxidase negative

What are coliforms? (Enterobacteriaceae Family)

Bacteria that ferment lactose

What are non-coliforms? (Enterobacteriaceae Family)

Bacteria that do not ferment lactose

Where is E.coli found?

Human gut

What does E. coli cause?

UTIs, diarrhea, baby diarrhea, travelers diarrhea

What does the coliform count tell us? (E. coli)

Indicates fecal contamination in water

Which strain causes travelers diarrhea? (Dangerous E. coli Strains)

Enterotoxigenic E. coli

Which strain causes intestinal inflammation? (Dangerous E. coli Strains)

Enteroinvasive E. coli is a pathogenic strain that invades the intestinal cells, leading to inflammation and diarrhea.

Which strain causes infantile diarrhea? (Dangerous E. coli Strains)

Enteropathogenic E. coli

Which strain causes hemorrhagic syndrome and kidney damage? (Dangerous E. coli Strains)

Enterohemorrhagic E. coli (e.g., 0157:H7)

Klebsiella pneumoniae is known for?

Nosocomial pneumonia and large capsule

What pigment does Serratia marcescens produce?

Redpigment called prodigiosin.

How is Salmonella Typhi (Typhoid Fever) transmitted?

Contaminated food, water, or personal contact

Where does Salmonella Typhi (Typhoid Fever) multiply?

In the small intestine

Are carriers possible? (Salmonella Typhi; Typhoid Fever)

Yes; chronic carriers shed from gallbladder

What do they cause? (Other Salmonella; Salmonelloses)

Gastroenteritis, food poisoning

Where are Salmonelloses found?

Poultry, dairy, reptiles, rodents

What illness does Shigella cause?

Dysentery and severe diarrhea, often with blood.

What is its virulence factor for Shigella

Shiga toxin

How is Yersinia Pestis (Plague) be transmitted?

Fleas and rats

What are the three forms?

Bubonic, septicemic, and pneumonic

Can Yersinia Pestis (Plague) be a weapon?

Yes; deadly and potentially antibiotic-resistant

What does H. influenza cause? (Haemophilus)

Meningitis, pneumonia, otitis media, and sinusitis

What vaccine protect against H. influenzae? (Haemophilus

Hibvaccine protects against invasive diseases caused by H. influenzae type b.

What does H. aegyptius cause?

Conjunctivitis (pink eye)

Prevention Tips

Wash hands, cook food, wash produce, pasteurize milk, get vaccinated

Bubonic

Bacillus multiplies in flea bite, enters lymph, causes necrosis and swelling called a bubo in groin or axilla

Septicemia

Progression to massive bacterial growth; virulence factors causes intravascular coagulation subcutaneous hemorrhage and purport; black plague

Pneumonic

Infection localized to lungs; highly contagious, fatal without treatment

E. coli Pathogens

1. Ingested of pathogenic E.coli

2. Colonization of intestinal respiratory or other mucosal surfaces

3. Passage through the mucosa

4. Resistant to complement and phagocytosis

5. System persistence and multiplication

6. Production of toxins

7. Shock and death

8. Localized infection

   E.coli = fimbrae; toxins