Exam 3 bacteria

Question 1

Shigella

Answer 1

Has 4 groups: A (S. dysenteriae), B( S. flexneri), C (S. boydii), and D (S. sonnei) Group a is the most virulent
Causes headache, bloody diarrhea, emesis, stiff neck convulsions, joint pain.
Non motile Gram negative rod NLF

Question 2

Salmonella

Answer 2

*Salmonella enterica a gram negative rod w/ over 2000 serotypes
*Found in eggs, chickens, tomatoes, lizards, and turtles
* Causes diarrhea, emesis, cramps, and fever
*High infectious dose

Question 3

What are the different strains of E.Coli?

Answer 3

STEC- Foodborne
ETEC- Diarrhea in developing countries and infants
EIEC-Diarrhea in developing countries and young kids
EPEC- Seen in infants. Antibodies found in breastmilk
EAEC- Children, travelers, aids patients

Question 4

E. Coli

Answer 4

*Escherichia coli a g-r LF MOTILE rod related to shigella
*Causes diarrhea, dysentery, hemolytic uremic syndrome depending on the strain
*Has 5 different strains and some are even native to the gut
* Three main methods of pathogenesis: toxin production, alterations in the host cell, cell invasion
*infectious dose depends on strain

Question 5

Listeria Monocytogenes

Answer 5

• Causes listeriosis
  *Motile, non-spore-forming, facultatively anaerobic, Gram-positive rod
  *Foodborne pathogen found in vegetation, water, and various other areas
  *can induce phagocytosis and reproduce w/in host cell
  *healthy= asymptomatic immunocompromised= fever, muscle aches, nausea, diarrhea

Question 6

Helicobacter pylori

Answer 6

• Causes gastritis (proven by Barry Marshall)
  *Short, curved, Gram-negative microaerophilic with multiple sheathed polar flagella
  *Destroy the mucous producing cells in the stomach causing ulcers that allow stomach acid to come in contact w/ connective tissue
  *Nausea vomiting, belching, peptic ulcers

Question 7

Leigonella pneumophilia

Answer 7

• Legionnaires’ disease
  *Gram-negative rod; fastidious facultative intracellular parasite that lives in freshwater protozoans
• Infection occurs when aerosol containing protozoan is inhaled
  *Headache, muscle aches, fevers, confusion, tremors/chills w/ sputum
• Prevent Phagosome-lysosome fusion and they multiply in macrophages

Question 8

Flu Virus

Answer 8

• Caused by Influenza A: Orthomyxoviridae
  *virulence is caused by HA and NA spikes on the outer portion of the virus.
  *Has 8 RNA segments inside. HA attaches to the receptors on host cell, NA destroys surface receptors. Kills cells and destroys mucociliary escalator
  *Headache, muscle aches, fever, sore throat, fatigue

Question 9

Giardia Lamblia

Answer 9

*AKA G. intestinalis a Protist that lives in the gut,
* Obtained through contaminated food , water, fecal/oral
*Exocystation in the small in–> 2 trophozoites that multiply via binary fission.
*Stay in the body or move to colon and return to cyst form. Is excreted from the body.

Question 10

Strep. pneumoniae

Answer 10

*Gram-positive diplococcus known as pneumococcus; lancet-shaped
*Thick polysaccharide capsule responsible for virulence
*90 different serotypes each with different capsular antigens
*cough, fever, chest pain, sputum production

Question 11

M. tuberculosis

Answer 11

*Mycobacterium tuberculosis
*Gram-negative rod with large capsule; produces big mucoid colonies
*Normal microbiota of gastrointestinal tract; may be found in mouth and throat
*Capsule is virulence factor: likely interferes with C3b
*affects very old or very young, or those with compromised immune system

Question 12

Histoplasma capsulatum

Answer 12

*A dimorphic fungi that grows within host macrophages as tiny oval yeast
*Inhaled microconidia taken up by macrophages
*Granulomas develop; resemble those of TB
*Grows in soils enriched with bird droppings
*Fever, cough, CP, SOB, headaches, chills, fatigue, body aches

Question 13

N. gonorrhoeae

Answer 13

*Causes gonorrhoeae an STI
*Gonococcus (GC), a fastidious, Gram-negative diplococcus
Pili (fimbriae) for attachment
*Attachment by pili to receptors on non-ciliated columnar mucosal cells
*Symptoms due to intense inflammatory response
*Produces protein that “steals” iron from host as one of many ways to avoid the immune system

Question 14

Neisseria meningitidis

Answer 14

*Causes meningococcal meningitis.
* A gram negative encapsulated diplococci
*Capsule allows passage into bloodstream an immune avoidance
* Spread via respiratory droplets will cause petechiae and inflammation
*younger pop. has highest risk and treated with pen or ceftriaxone

Question 15

Treponema Pallidum

Answer 15

*Causes syphilis
*Very slender, highly motile spirochete; outer membrane lacks LPS
*Viewed with dark-field microscopy, silver stain
* Have endoflagella
*Human only transmission
*penetrates mucous membrane, damaged skin; infectious dose less than 100 cells

Question 16

Papilloma Virus

Answer 16

*Causes HPV
* Human papillomaviruses, non-enveloped, double-stranded DNA viruses of Papillomaviridae
*Warts and papillomas form
* 100+ types and can be cancer causing depending on the strain
*An STI that has a vaccine (Gardacil9)

Question 17

Trichomonas vaginalis

Answer 17

• Caused by a protozoan w/ four posterior flagella
  *Jerky motility w/ poor outside survival
  *Rates highest in men, women with multiple sex partners
  *Causes tissue damage; increases risk of infection by HIV
  *