Gram (-) Cocci Flashcards Preview

Microbiology Rapid Review > Gram (-) Cocci > Flashcards

Flashcards in Gram (-) Cocci Deck (12):
1

Oxidase positive encapsulated diplococci, growth on Chocolate agar, ferments glucose and maltose, transmitted by respiratory droplets

Neisseria meningitidis

2

Strain of N. meningitidis that is most common

B strain (NOTE: vaccine contains strains Y, W-135, C, and A. B strain is not immunogenic so no protection would be induced anyway)

3

Virulence factors of N. meningitidis?

Polysaccharide capsule (detect with latex particle agglutination)

IgA protease (allows colonization in pharynx)

Endotoxin (fever, septic shock)

Pili

Deficiency in late complement components (C5-C8) predisposes to bacteremia

4

What indicates that N. meningitidis infection has spread to blood? What are dangerous complications of fulminant cases of meningitis caused by N. meninigitidis?

- bacteremia indicated by rash

- Waterhouse-Friderichsen syndrome, DIC, shock, coma, death

5

What are the best ways to diagnose N. meningitidis?

Gram stain of CSF (look for G- diplococci), PCR, latex agglutination to detect capsule

6

Why are all infants born in the US given erythromycin ointment on their eyes?

Prevention of ophthalmia (N. gonorrhea infection that leads to blindness if untreated)

7

Oxidase positive diplococci, ferments flucose, growth on chocolate agar, sensitive to drying and cold, sexually transmitted disease

Neisseria gonorrhoeae

8

Which occurs more commonly, gonorrhea or chlamydia?

Chlamydia

9

What are the pathogenic factors of N. gonorrhoeae?

Pili (attachment), Opa (adherence), IgA protease, invasion of mucosal surfaces to cause inflammation

- all can undergo antigenic variation, which causes antibiotic resistance

10

Symptoms of a gonorrhea infection

Males: more likely to present, purulent urethral exudate

Females: more likely to be asymptomatic, endocervitis, PID, arthritis

11

Diplococcus, causes otitis media or sinusitis, normal flora of upper respiratory tract

Moraxella catarrhalis

12

Top 3 most common causes of otitis media

1) Streptococcus pneumoniae

2) Haemophilus influenzae

3) Moraxella catarrhalis