Bacteria

Question 1

Facultative bacteria

Answer 1

can divide independently and on agar plates but enter host cells as part of their pathogenesis

Neisseria, Enterics, Mycobacter, Bacilli, Legionella

Question 2

Obligate Intracellular Parasites

Answer 2

require host cell resources to multiply

Rickettsial, Chlamydia

Question 3

Intracellular pathogens

Answer 3

uses infected macrophages for transport around body and evade humoral and surface-innate immunity (actin-based cell-cell spread)

Question 4

Type 3 secretion systems

Answer 4

establishes intracellular lifestyle. enchances phagocytosis by target cell type or alter the endosome so that lysosomes fail to fuse to it.

Question 5

Tetracycline

Answer 5

antibiotic that crosses the human cell membrane and remains active. contraindicated in pregnancy

Question 6

Listeria monocytogenes

Answer 6

facultative intracellular bacterium, causes gastroenteritis. after endocytosis, escapes endosome and uses actin based motility to spread between cells. can cause meningitis in immunosuppressed patients and will complicate pregnancy.

Question 7

Rickettsia rickettsiae

Answer 7

obligate intracellular bacterium, transmitted by ticks. infects endothelium of blood vessels causing leakage and rocky mountain spotted fever. has virulence factors for adhesion, cell entry, endosomal escape and actin based cell-cell spread

Question 8

Chlamydia

Answer 8

obligate intracellular pathogen, rugged elementary bodies unpack into larger delicate reticulate bodies after cell penetration. carries T3SS for entry and can convert back into elemetnary bodies. infection can lead to reactive arthritis

Question 9

Vibrio

Answer 9

curved, Gram (-) rods, ocean dwelling pathogens, results in fecal-oral gastroenteritis

Question 10

V. cholerae

Answer 10

Vibrio, transmitted to humans by fecal-oral route, secretes choleragen, causes watery diarrhea

Question 11

H. pylori

Answer 11

Vibrio, causes most stomach ulcers, associated with stomach cancer, produces urease (converts urea to ammonia) which neutralizes stomach acid

urea breath test: patients exhale radiolabeled carbon dioxide

treated with antibiotics, pepto bismol, proton pump inhibitors

Question 12

Spirochetes

Answer 12

wide variety of transmission (sexual, vector borne, environmental), crosses easily into blood stream, can cross blood-brain barrier leading to meningitis. virulence factors include immune evasion, not very antigenic

no vaccines but easily treated with antibiotics, diagnosed using Argyll-Robertson pupil

Question 13

Jarisch-Herxheimer reaction

Answer 13

reaction to treatment for Sphyilis and Lyme disease

Question 14

Sphyilis

Answer 14

Spirochete, 3 stages: painless chancre, rash with flulike symptoms, cardiac or CNS involvement.

Question 15

Lyme Disease

Answer 15

Spirochete, transmission by ticks, 3 phases: skin infection (rash), immune/neurological issues, fibromyalgia. Treated with doxycycline

Question 16

Obligate (non-facultative) anaerobic bacteria

Answer 16

derives all their ATP from fermentation, can be either normal flora or soil organisms.

virulence determined by exotoxin expression

Question 17

Major pathogenic anaerobes

Answer 17

Clostridium (gram positive), actinomyces (gram positive), GNAB (normal flora), actinomyces (normal flora), C. difficile (normal flora)

Question 18

Enterobacteriaceae

Answer 18

Shigella, E. coli, Salmonella, Yersinia

gram negative, non-sporulating, straight rods, facultative aerobes, catalase positive, oxidase negative, glucose fermenters

fecal oral transmission

Question 19

M. tuberculosis

Answer 19

acid fast positive, transmission by inhalation, results in granulomas

Question 20

Atypical mycobacteria

Answer 20

environmentally acquired infection, does not cause TB or leprosy, usually cutaneous infection

Question 21

M. leprae

Answer 21

slowest growing human pathogen

Hansen’s disease (leprosy) presents on a range from tuberculoid to lepromatous

treated with dapsone and rifampin

Question 22

Reactive Arthritis

Answer 22

triggered by infection with Shigella, Salmonella, Yersinia, Campylobacter, Chlamydia

Question 23

Hemolytic uremic syndrome

Answer 23

Infection by shigella or enterohemmorhagic strain of e. coli

Patients positive for Human Leukocyte Antigen (HLA)-B27

Question 24

“ICU Bugs;” major opportunistic nosocomial pathogens

Answer 24

Klebsiella, Enterobacter, Serratia, Proteus, Providencia, and Morganella