Exam 1a. Flashcards

(98 cards)

1
Q

Host defenses against encapsulated bacteria

A
  • Skin and Mucus membranes
  • White Blood Cells (Neutrophils and Lymphocytes)
  • Immunoglobulins
  • Complement
  • Cytokines and other acute phase reactants
  • The Spleen
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

How does the polysaccharide capsule protect the bacteria

A

inhibits phagocytosis of the organism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

how do pili protect the bacteria

A

Promotes attachment of the organism to mucosal surface

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Where is the polysaccharide capsule?

A

around all the outer cellular material

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Pathogensis: bacteria goes into the epithelium, then it can cross the blood-brain barrier, and can cause local infections like p. meningitis

A

Streptococcus pneumoniae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What part of the immune system is designed to recognize polysaccharide capsule antigens?

A

Marginal zone B cells

- children don’t have good B cell immunity until 2+y/o

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

does the innate immune system protect against encapsulated organisms

A

yes, we make antibodies during colonization or infection- basis for vaccines

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are the encapsulated organisms

A
  • Neisseria meningitidis
  • Neisseria gonorrhea
  • Streptococcus pneumoniae
  • Haemophilus influenzae
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What type of bacteria is Neisseria meningitidis

A

aerobic gram negative diplocccus**

encapsulated

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Diseases caused by Neisseria meningitidis

A
  • Meningococcemia (bacteremia) *more dangerous

- Meningococcal meningitis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Virulence factors of N. meningiditis

A

potent endotoxin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Neisseria meningitidis reservoir

A

young adults

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Sx of Neisseria meningitidis

A

purpura and petechiae rash that is non-blanching

-rash may become subcutaneous bleeding and necrotic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

when do we give the meningococcal vaccine

A

age 11-12, booser at 16 routinely or

>2 months if increased risk of disease (adolescents, immune disorder*, occupational exposure, travel exposure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

pathogensis: -Exposure to colonized adult
- Acquisition of organism in nasopharynx
- Asymptomatic carriage, then immunity and colonization for 2-4 months OR Colonization which can result in Bacteremia and/or Meningitis

A

Neisseria meningitidis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

HibMenCY, MCV4-D, MCV4-CRM, MPSV4, MenB-4C and MenB-FHbp are vaccines to protect against

A

Meningococcal

**choice of vaccine depends on age

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Gram negative kidney bean shaped diplococci

A

Neisseria gonorrhea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Not encapsulated but has lipopolysaccharide

A

Neisseria gonorrhea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What can Neisseria gonorrhea be grown on

A

Chocolate agar/ carbon dioxide

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Neisseria gonorrhea: oxidase +/-? and Catalse +/-?

A

+, +

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

When is it important speciate Neisseria gonorrhea

A

when found in children because it could indicate sexual abuse
**isolate using 2 methods in children

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What does Neisseria gonorrhea ferment?

A

glucose

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

How can you identify/speciating Neisseria gonorrhea in the lab?

A
  • sugar fermentation
  • enzymatic
  • fluorescent antibody
  • Nucleic amplication (NAAT)***
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Virulence characteristics of Neisseria gonorrhea

A
  • pili
  • outer membrane proteins
  • ability to use iron
  • IgA protease
  • LPS
  • cell wall peptidoglycan
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
When did the incidence of Neisseria gonorrhea increase drastically and where is it most prevalent and in who is it most prevalent in
1970s - in the south as it is related to income - 20-30s, - Blacks
26
Diseases caused by Neisseria gonorrhea
- vaginitis - urethritis - pharyngitis - PID and salpingitis - rectal infection - ophthalmia neonatorum - disseminated disease (joint inflammation)
27
many strains of N. gonorrhea are resistent to what
penicillin
28
What is N. gonorrhea treated with
Celfixime | but refer to CDC for guidelines of most recent treatment
29
How to protect against N. Gonorrhea
no vaccine
30
Bile sensitive, alpha hemolytic streptococci
Streptococcus pneumonaie
31
where is Streptococcus pneumonaie commonly found
Normal nasopharyngeal flora (in 15% of children and 50% of adults)
32
>90 different serotypes recognized | -Type based on capsular polysaccharide
Streptococus pneumonaie
33
What disease does Streptococcus pneumonaie cause
- otitis media, - pneumonia - meningitis - sinusitis
34
How do you identify Streptococcus pneumonaie in the lab?
- Alpha hemolysis on sheep blood agar - Autolyze easily in blood culture bottles - catalse negative - Can be typed by latex agglutination
35
What type of bacteria is Streptococcus pneumoniae
Gram positive diplococcci (may be gram variable)
36
Bile soluble and susceptible to optochin
Streptococcus pneumoniae
37
Who is most sucseptible to Streptococcus pneumonaie
~6 month y/o
38
How is Streptococcus pneumoniae treated
amoxillin
39
PCV12, PCV7, PCV10, PPSV23, PCV7, PCV13* vaccines protects against
Streptococcus pneumoniae
40
Pleomorphic gram negative coccobacilli
Haemophilus influenzae
41
- Six encapsulated types (A,B,C,D,E,F) - 95% of invasive disease caused by B - Also are non-encapsulated strains
Haemophilus influenzae
42
reservoir for Haemophilus influenzae
colonized infants
43
best growing environment for Haemophilus influenzae
- Grows on chocolate agar (contains hemin and NAD) - Grows best in 5-10% CO2 * Colonies on agar are transparent, with a “mousy” odor
44
identified by latex slide agglutination as type B
Hib
45
What diseases does Hib cause
Meningitis, Epiglottiti, Pneumoni, cellulitis
46
PRTP-T (ActHIB), PRP-T (Hiberix), and PRP-OMP (PedvaxHIB protect against
Hib
47
There has been a ____% decrease in invasive Hib disease since prevaccine era
99%
48
____ likes to localize and____ likes to spread
Staph-localize | Strep-spread
49
Gram + cocci, catalse +, pairs and groups
Staphylococcus
50
Gram + cocci, catalase -
Streptococcus
51
what medium can you grow gram + aerobic organisms on
- Blood - Chocolate * not MacConkey
52
What staphlococcus species is cogulase positive and what color does it turn
S. aureus | Hemolytic) (Golden
53
What test separates S. aureus from Coag. neg. Staph
Coagulase test
54
Staphylococcal virulence factors
1. Entertoxin A-E 2. Exfoliatin A-B 3. TSST-1 4. Enzymes 5. Cell wall
55
What Staphylococci are most commonly found in the nose and hwere else
S. aureus | -skin and throat
56
What Staphylococci are most commonly found on the skin and where else
Coagulase-negative Staph | -nose and throat
57
Diseases caused by Staphylocci
``` Sinusitis (uncommon cause of local respiratory spread) Osteomyelitis (local bone absecess) Scalded Skin Syndrome Scarlet fever Bullous impetigo TSS Furunculosis (boil) ```
58
Lymphadenitis is caused by
S. aureus
59
What is the most common form of food poisioning
Enterotoxins
60
Enterotoxins ___ and ___ are associated with TSS due to local infections
B and C
61
-Heat and acid stable proteins 8 serologically distinct: -A-E (C1,C2,C3) -G-I
Enterotoxins
62
What do Enterotoxins cause when ingested by contaminated foods
vomiting and diarrhea | -Mediated by Mast cells
63
What causes Scalded Skin Syndrome
S. aureus
64
Bollous impetigo is commonly seen in who
young infants
65
- Acute Fever - Erythroderma (Desquamation - usually late) - Hypotension - Multi-organ system involvement (at least 3)
TSS
66
What are these risk factors for? - Exposure to TSST-1 (+/- enterotoxin) S. aureus strain. - Growth of organism under conditions that promote toxin production. - No pre-existing antibody to toxin(s). - Genetically predisposed
TSS
67
S. aueus with mecA gene or PB2A positive
MRSA
68
S. aueus with mecA gene or PB2A negative
MSSA
69
Coagulase clumping factor causes
localization of staph
70
Scalded skin syndrome toxin(s)
Exfolliatin
71
scarlet fever toxin(s)
Exfolliatin or TSST-1
72
Most staph are resistent to what antibiotic
penicillin
73
antibotics contain focal infections but you still have to ____
drain
74
Hemolysis results of: | alpha, beta, and gamma
alpha-green beta-clear gamma- no hemolysis
75
Sub groups/Lancefield Groups of beta streptococcus
``` Group A (Strep. pyogenes) Group B (Strep. agalctiae) ```
76
Strep alphas:
Optochin
77
strep alpha: optochin test positive =
S. pneumoniae
78
Strep. gammas:
Enterococcal Others
79
Lancefield groups are based on
cell-wall carbohydrate antigens
80
M protein is a major virulence factor in
S. pyogenes | Lancefield Group A
81
S. pyogenes is normal flora where
mouth
82
Virulence factors of Group A Strep:
1. DNAase B 2. Streptokinase 3. Hyaluronidase 4. Proteinase
83
Common sites of S. pyogenes Disease
1. perineal/perianal cellulitis 2. Vaginitis 3. Tonsiliits/pharyngitis
84
what is the most common cause of bacterial pharyngitis
Strep. pyogenes
85
Virulence factor of Strep. pyogenes
M protien
86
``` Of these symptoms what suggest Strep and what suggest virus Tender lymph nodes Close contact Cough Runny Nose Age ```
``` Tender lymph nodes= Strep Close contact= strep Cough=virus Runny nose= virus Age ```
87
Where do you need to swab when testing for strep
tonsils, posterior wall, palate, and buccal mucosaa
88
Toxic complications of Strep pharyngitis
Scarlet fever | TSS
89
These can result from: - Acute Rheumatic Fever - Post-Streptococcal Reactive -Arthritis - Glomerulonephritis - PANDAS
Non-suppurative complications from Strep. pharyngitis
90
These can result from: - Otitis media - Sinusitis - Parapharyngeal abscess - Cervical adenitis - Pneumonia
Suppurative complications from Strep. pharyngitis
91
Skin manifestations from GAS infection
- impetigo - cellulitis - necrotizing fasciitis
92
sunburn rash that peals | -raspberry tongue is a cause of
Scarlet fever
93
cause of rheumatic fever
untreated strep
94
impetigo, post-streptococcal glomerulonephritis and pharyngitis, rheumatic fever are what type of strep. pyogene strains
non-invasive
95
scarlet fever, septicemia, necrotizing cellulitis/fasciitis/TSS are what type of strep. pyogene strains
invasive
96
Dx of Group A strep
Culture
97
rhemtaic fever virulence factor
auto-immune
98
Commonly found in male urethras and the birth canal
Group B Strep