Gram Negative Pathogens - Robison

Question 1

What constitutes the larges group of human pathogens?

Answer 1

Gram negative bacteria; usually cause disease and death in humans

Question 2

Describe Neisseria

Answer 2

The only genus of Gram negative diplococci that regularly cause disease in humans

aerobic, catalase positive, oxidase positive

Cause gonorrhoeae and mengingitis

Question 3

What are the virulent factors in neisseria gonorrhoeae?

Answer 3

pili because that is how it holds on to the cell

Question 4

What was the past therapy for gonorrhea and why does it not work now?

Answer 4

Penicillin, but not it is resistant

Question 5

Describe Neisseria meningitidis

Answer 5

Humans are the only carriers
Can be normal in microbiota
Transmitted through respiratory droplets and being in close contact

Dangerous!!!! Can die within 6 hours after intial symptoms

Question 6

What are symptoms of meningitidis and meningococcal septiciemia? What are treatments?

Answer 6

Stiff Neck
Fever, headache, bright lights,
Blood coagulation

treatments are vaccines, penicillin, or cephalosporins

Question 7

What are virulent factors of N. meningitidis?

Answer 7

capsule and endotoxin

Question 8

Describe Enterobacteriaeae

Answer 8

gram negative, faculatively aerobic rods, ferment, catalase positive, oxidase negative
Usually killed by disinfectants

Question 9

What are the three types of enterobacteriaceae surface antigens?

Answer 9

O- parts of lipopolysaccharides
K- capsule (Kapsule - german)
H- flagella

Question 10

What are the three groups of enterobacteriaceae?

Answer 10

Coliforms- ferments lactose, part of the normal microbiota and may be opportunistic
Non coliforms opportunists- do not ferment lactose
Frank pathogens- do not ferment lactose

Question 11

What is the most common and important coliforms? And what are characteristics

Answer 11

E. coli
UTIs and gastroenteritis are the most common E.coli diseases
Many different varieties

Question 12

What is a type 3 secretion?

Answer 12

Protein complex that acts like a syringe
Usually in a strain of pathogenic E. coli

Causes diarrhea, hemorrhagic colitis, and HUS

Question 13

Describe shigella

Answer 13

gram negative and non motile
parasite of GI tract
produces diarrhea inducing enterotoxin
causes shigellosis (dysentery)

Question 14

How is shigella spread?

Answer 14

flies, fingers, fomites, food, feces

Question 15

What is the mech of shiga toxin?

Answer 15

AB toxin

inactivates ribosomes- aka no more protein synthesis

Question 16

Which two organisms can invade a host cell?

Answer 16

Listeria and Shigella

Question 17

Describe salmonella

Answer 17

Gram negative, motile, bacilli
Enterobacteria
Found in intestines and feces of most birds, reptiles and mammals
People usually infected by consumption of contaminated foods

Question 18

What does samonella enterica serovar Typhi cause?

Answer 18

Typhoid fever
Humans are the only hosts
Usually infected through food and affects the gallbladder and liver
“Typhoid Mary” - most infamous carrier; cook
Treated with vaccines and antimicrobial drugs

Question 19

What does Klebsiella cause?

Answer 19

pneumoniae
Enterobacteria
produces a capsule that protects from phagocytosis

Question 20

What is Yersinia?

Answer 20

normal pathogen of animals with 3 important species
Enterobacteria
Y. enterocolitica causes symptoms of appendicitis
Y. pseudotuberculosis causes less severe intestinal inflammation
Y. pestis causes bubonic plague!

Question 21

Describing bordetella

Answer 21

small aerobic gram negative non motile coccobacillus
causes whooping cough
inhaled in aerosols and grow on epithelial cells

Question 22

Describe pseudomondads

Answer 22

Gram negative aerobic bacilli
Usually in plants and wter
opportunistic bacteria
Problematic in hospitals

Question 23

What is a common infector of severe burns?

Answer 23

Pseudomonas aeruginosa

difficult to treat with antibiotics

Question 24

Describe francisella tularensis

Answer 24

non motile, strictly aerobic, gram negative
TINY ORGANISM
causes tularemia
Spread to humans through bite of tick or deerfly
usually misdiagnosed because it is similar to other diseases