Neisseria, Haemophilus and Bordetella Flashcards
(53 cards)
1
Q
What is Neisseria (NOIR SERIES) morphology?
Gram_____
kid____ _____plo
c_____ and p______
A
- G NEGATIVE
- “kidney bean” diplococci (red handcuffs)
- capsules (important virulence factor) and pili (antigenic variation–gold, silver chains)
2
Q
What are the cultural characteristics of Neisseria?
- What enhances its growth?
- what kind of grower is it/on what media?
- how are they classified?
A
- growth enhanced in CO2
- FASTIDIOUS species, required enriched media (harder to cultivate); CHOCOLATE BAR agar
- OXIDASE POSITIVE
- classification based on measuring acid production with sugar oxidation reactions
3
Q
N. gonorrhoeae classification (based on oxidation)?
A
Oxidase Positive…GLUCOSE
4
Q
N. meningitidis classification (based on oxidation)
A
Blood agar..Oxidase Positive..GLUCOSE and MALTOSE
5
Q
Why is complement deficiency a problem with Neisseria disease? (Thayer Martin as “MAC” Private Eye; showing 5-9)
A
Bactericidal activity vs. Neisseria requires intact complement.
-6000x increase risk if C5-9 missing (important terminal components for MAC)
6
Q
N. meningitidis
A
capsule and LPS
7
Q
N. gonorrhoeae
A
Pili and OMPs
8
Q
What are the three components of N. mening antigenic structure?
A
- polysaccharide capsule
- 13 serogorups (A.B.C.Y.W-135)
- all immunogenic except Group B (no vaccine for Type B) - outer membrane proteins
- LPS
9
Q
N. mening pili (1/3) cause pathogenicity by?
A
- attachment
- multiply at site
- post translational modification of Type 4 pilus
- disperse and invade
10
Q
N. mening Polysaccharide capsule (2/3) cause pathogenicity by?
A
- bloodstream invasion and survival
- capsule inhibits phagocytosis
- CNS penetration
11
Q
N. mening LPS (3/3) cause pathogenicity by?
A
- LARGE amounts cause cell damage and systematic inflammation
- leads to intense septic shock-like state
12
Q
What is the epidemiology of Meningococcal disease?
- developed world-which are most common
- developING-which are most common
Where does it occur and how is it transmitted?
A
developed (B, rarely A)
- sporadic cases or outbreaks in closed populations
- usually Group B, rare community Group A outbreak
devolopING (A or W135)
- large outbreaks of A or W135
- sub-Saharan meningitis belt (*among infants), Mecca pilgrimage
Transmitted by respiratory droplets
-1000x INCREASE attack rates in household contacts (give prophylactic AB to contacts)
13
Q
In the US who gets Meningococcal?
3 main groups
A
Children under 5, teens and young adults (college aged). MSM
14
Q
Meningitis Step-by-step
- adhere to who and who and where
- _______cytoses the cells, into _______, ultimately________
- how does it survive in the bloodstream
- Who turns on intense inflamm and HOW?
- what do the organisms cross and where do they go?
- What do they do at their final destination?
**what is the endotoxin? envelopes on fuego
A
- adheres to ciliated and non-ciliated cells in the respiratory mucosa
- transcytoses the cells, gets into the sub mucosal surface, ultimately gets into the BLOODSTREAM, spreads hemotogenously
- polysaccharide capsule
- endotoxin that is released at that location can cause intense inflammation by turning on inflamm cytokines and activating complement
- some of the organism may then cross the BBB and get into the subarachnoid space
- It will then multiply and cause meningitis
**endotoxin=lipooligosaccharides (LOS proteins-ENVELOPES proteins=Neiserria version of LPS). LOS proteins outgrow bacteria surface, bleb off, cause massive inflamm resp=stack of ENVELOPES on fire.
15
Q
What are the clinical manifestations of Neisseria mening Infection?
- _______ colonization followed by a. or b.
- The crux: Meningococcemia (profound ____)
- SHAP - Skin
- Head
A
- RESPIRATORY (nasopharynx) colonization followed by a. overt disease or b. transient carrier state (immunizing event…some ppl it starts to disseminate before antibody develops)
- Meningococcemia (profound SEPSIS)
- Shock
- Hemorrhage aka Thrombocytopenea (due to disseminated intravascular coagulation, most pts have skin manifestations-red boxers, petecheae)
- Purpura (rash of purple spots on the skin caused by internal bleeding from small blood vessels)
- Adrenal hemorrhage-may make shock worse - Skin-petecheae (due to thrombocytopenea aka hemorrhage)–>purpura
- Meningitis-headache, mental status changes, neuro signs (b/c meninges)
16
Q
Where did the leaky capillaries come from?What is the consequence of leaky capillaries?
A
LOS proteins–> inflamm response–>increased capillary permeability–>hypovolemia–>petechial rash (sign of thrombocytopenia)–>purpura or ecchymosis=sign illness is progressing to DIC
**capillary leakage can lead to hypovolemia and SHOCK (electrical socket)
17
Q
As person becomes hypovolemic _______ ______ increases in an attempt to maintain ___. _________ become poorly perfused and ________. The resulting ___________ further contributes to the _______ and is very often fatal. The destruction of the ________ is known as ______________
A
- peripheral vasoconstriction
- bp
- Adrenals
- infarct
- adrenal insufficiency
- shock
- adrenals
- Waterhouse-Friderichsen syndrome (water tower outside the house)
18
Q
Besides the top 4 1. 2. 3. 4. What are the other clinical manisfestations of N. mening infection?
A
- Respiratory colonization
- Meningococcemia (SHAP)
- Skin
- Meningitis (Head)
Other: pneumonia, arthritis, pericarditis, **urethritis (due to the mechanism of acquisition for MSM)
19
Q
What two tests are used for a laboratory diagnosis?
A
- gram smear-CSF
2. Cultures: CSF, blood, skin (lower likelihood of recovering this sample)
20
Q
What is special to note about the gram stain of Neiserria?
A
Due to the magnitude of bacteremia and number of organisms in the bloodstream, there will also be some organisms on a blood smear.
21
Q
What would you use to treat N. mening?
A
- Penicillin-resistance is uncommon
- Ceftriaxone (firefighter with 3 axes), penetrates BBB better than Pen G
- use Pen G if sensitive - Other cephalosporins (**3rd generation)
22
Q
What are the two main modes of prevention of N. mening and who re they given to?
A
- Chemoprophylaxis given to household contacts
a. Rifampin-couple days dose
b. Ciprofloxacin
c. Ceftriaxone (1 dose-iv) - Vaccine-polysacch with A, C, Y, W-135 conjugated to diphtheria toxoid (B IS NOT INCLUDED BECAUSE IT ISNT IMMUNOGENIC)
- given to adolescents 11-12 (boost at 16/17) nd at risk adults.
* *New Serogroup B vaccines (MenB-FHbp, MenB-4C)
- recombinant protein vaccines
- recommended for very high risk only
23
Q
For person at ________ risk for MeninDZ ______ is recommended. What are these 7 groups of ______ person?
A
- increased
- vaccine
- at risk
- ALL children at age 11
- college frosh living in dorms
- microbiologist routinely exposed
- pops in which an outbreak occurs (MSM and travelers)
- military recruits
- ppl with increased susceptibility
- asplenia (no spleen)
- terminal complement deficiency - travelers to hyperendemic regions
- sub-Saharan Africa
- Saudi Arabia
24
Q
What are the four main antigenic structures of N. gonorrhoeae? (POPeR)
- repeating protein
- outer membrane protein
- WHERE are the greek bars
- best blocker in the league
* *BONUS: name of the space occupied by peptidoglycan
A
- Pili-stacked units of repeating protein (mz 19kd)
- PorB-outer membrane protein I-PORIN
- pores (channels) on the surface of the organism
- facilitate epithelial cell invasion on other cells - Opa-adherence proteins confer opaque appearance to colony
- opaque=localized dz
- transparent=disseminated dz - Rmp Proteins-stimulate blocking antibodies
* *periplasmic space
25
Antigenic variation in Greeks and repeating protein stacks
Pili (RECOMBINATION)**
- via transformation event, occurs in the person to evade the immune system
- DNA recombination involving transfer of variable sequences from unexpressed (silent) loci, pilS to expression locus, pilE
Opa (ON/OFF)**
- up to 11 different Opa genes in genome
- switch on and off Opa genes by varying length of 5 nucleotide (CTCTT)^n repeats in the leader sequence encoding the Opa gene
- alteration in number of repeats turns on or off expression (depends on whether or not its in/out of phase)
26
What is the epidemiology of Gonorrhea?
- How is is transmitted?
- What groups have the highest rate?
- Who are reservoirs?
- What are the different risks for M&W?
1. across mucosal surfaces by direct contact
2. adolescents and young adults
* *3. reservoir-asymptomatic (50% women, 5+% men), no symptoms but can transmit
4. Risk: M=20% per contact with infected women, W=50% per contact with infected man
27
_________ of Gonorrhea - _______ and _______
1. _________ with _______ and _______
2. __________ cell _______ (best shown in ______ cell models)
3. _____Feliz + _______ fragments ---> fuego
4. Spread to _____ _____
a. M
b. F
c. Odell Beckham Jr
d. _____ resistant strains
Pathogenesis, Invasion, Damage
1. Attachement
a. pili-urethral, vaginal, fallopian tube, sperm, neutrophils
b. opa-cervial, urethral and other gonococcal cells
2. Epithelial cell invasion involves Por B + others
- best shown in fallopian cell models, similar to mening
3. LOS (envelopes) and peptidoglycan fragments--> inflamm resp and damage
4. Spread to deeper structures
a. M: direct to prostate, epididymus
b. F: paracervical glands by direct extension
c. carried by sperm to fallopian tubes (pelvic inflammatory dz)
d. serum resistant strains invade bloodstream and disseminate
28
What are the main modes of immune evasion in N. gonorr? (A-BR[greek+stacks]iE[feliz+league blocker])
1. Antigenic and phase Variation
2. Resist phagocytosis (Opa + pili)
3. Bind host transferrin, lactoferrin--> iron (important GF)
4. IgA 1 protease
5. Evade serum antibody and complement mediated killing
- LOS sialylation
- Rmp stimulates "blocking antibodies
29
Primary (localized dz) of Gonorrhea
* *1. Urethritis-(M) burning upon urination and purulent prolific urethral discharge, no systemic signs
* *2. Cervicitis-(F)
- endocervix=site of infection
- squamous epithelium of vagina is resistant, doesnt attach N. gonorrhea, causes endocervititis inflammation, mostly nothing but others will get serious inflamm then discharge
3. Proctitis-pain on defecation, purulent discharge from anal area
4. Pharyngitis-if pharynx after oral sex, most asymptomatic, though some have sore throats
5. Conjuctivitis (eyes)-in two settings
a. woman delivering has active gonorrhea and baby passing through can get it will now give tropical AB
b. STI-purulent, lots of redness and inflammation
30
Secondary (local invasion or disseminated)
A. 1:m + 2:f
B. A&D
1. Endometritis/Salpingitis (PID-pelvic inflammatory dz)
- F: ascend in women, there is pain, fever, damage to fallopian tubes. Symptoms: lower abdo pain, can lead to infertility after more than one episode
2. Epididymitis/Prostatitis
- M: associated with pain, fever, marked testicular swelling
* *-skin lesions and arthritis if it gets into the blood system and disseminates.
4. Arthritis
- joints tender and inflamed
- mostly dorsal tendon of the wrist
- in some pts: single joint, septic arthritis--> decreased range of motion, full of puss, often knee, needle would reveal purulent fluid
- Tenosynovitis
1. Dermatitis
- distal extremities; hands, arm, feet, lower legs.
- prominent papules with center
31
What are the three laboratory diagnosis for N. gonorrhoeae? (GCN)
1. Gram Stain-urethra, cervix, joint fluid
- 95% sensitive from male urethra
- 50-70% sensitive from uterine cervix (competing vaginal flora can make it difficult to make ids)
2. Culture
- require chocolate agar and CO2
- Martin Lewis-antibiotics select for N. gonorrh
- Ox+, Oxidize GLUCOSE (not M)
3. Nucleic Acid Amplification (PCR)
- direct detection from clinical specimens
- genital, oral, anal, urine* (easier to collect ample when dealing with urethral or cervical gonorrhea)
- cannot test antibiotic susceptibility
32
Treatment of Gonorrhea
* *1. Ceftriaxone (injectable, NO ORAL TX)+Azithromycin (for C. trachomatis; co-infection)
- all single dose
2. OR + Doxycycline (for C. trachomatis)
- 7 days course
3. Penicillin resistance-two types
- decreased affinity for peni of PBP (low level resistance)
- plasmid-mediated TEM-type beta-lactamase (PPNG)
- high level, pen resistance
33
Morphology and Staining Haemophilus influenzae
- gram-NEGATIVE coccobacilli
| - short: 0.5-1.5 um
34
What are the three classifications of H. influenzae?
1. Serotypes: a-f by polysaccharide capsule
2. Biotypes: using 3 biochem rxns
- only for epidemiological studies
3. Biogroups
- H. influenzae biogroup aegyptius causes Brazilian purpuric fever
35
Three main antigenic structures of H. influenzae? (PEP-Poly had Endo with Phil)
1. Polysaccharide capsule
- 6 types: a-f
* *Type b-polyribitol phosphate (anti-phagocytic)
- antibody protective
2. Pili
3. Endotoxin
36
What is the epidemiology of Type __ H. influenzae?
Who gets it? What age? Where?
Type B Epidemiology
1. invasive childhood infections until 1986
2. 94% decline-vaccine ('87-'93)
- 23 cases 2010
- mjr childhood pathogen in underdeveloped countries
3. Peak incidence: 6 mo. to 2 yo
- meningitis, septicemia, cellulitis:
37
What are the clinical manifestations of H. influenzae Type b? ...CAME
1. Cellulitis: children 2-4
- purple erythema; cheek, periorbital
- fever, toxicity
2. Arthritis
3. Meningitis: children
4. Epiglottis-children 2-4
- acute supraglottic cellulitis
- fever, sore throat, stridor, cherry red
38
What are the clinical manifestations of NONTYPABLE H. influenzae?...SOB...unencapsulated
1. Sinusitis-acute and chronic
2. Otitis media-middle ear infection
3. Bronchitis-esp. COPD (exacerbation of COPD, lower tract infection)
39
What allows a diagnosis of h. influenzae?
1. Gram stain-CSF, joint fluid
2. Culture-CHOCOLATE agar
3. Nonmotile, NON-sporeforming
4. Requires GF from blood
**-Factor 10 (Hematin)
**-Factor 5 (NAD)
[X and V strips alone are INSUFFICIENT, need BOTH]
-both supplied by LYSED but not whole blood
40
Tx for H. influenzae
1. Antibiotic therapy-severe disease
- broad spectrum cephalosporins (2nd and 3rd)
2. less severe-sinusitis, otitis (use oral AB)
- amoxicillin/clavulanate
- trimethoprim-sulfamethoxazole
- fluoroquinolones
3. 25-50% produce beta-lactamase
- ampicillin resistant
41
Prevention of H. influenzae via V(C)P?
1. Vaccine
- PRP-protein conjugate vaccines
- -T-cell dependent antigens (present in very young babies, the INDEPENDENT ones dont stim immune resp till 6-8mo)
- Universal vaccination of children
- age 2 mo
2. Chemoprophylaxis household contacts
- Rifampin
42
Other H Species
Respiratory: H. parainfluenzae
Conjunctivitis: H. aegyptius
Endocarditis: H. (aggregatibacter) aphrophilus, H. parainfluenzae
Chancroid (STD): H. ducreyi
43
Morphology and Staining of Bordetella pertussis?
* *-gram NEGATIVE coccobacilli
| 0. 5-1.0 um
44
What is the structure of B. pertussis?
| What are its virulent determinants?
- no capsule
1. **adhesins
2. ***Pertussin Toxin (PT)-exotoxin that is a MAJOR virulence factor for this organism
3. adenylate cyclase toxin
4. **tracheal cytotoxin-peptidoglycan fragment
- causes extrusion of ciliated tracheal epithelial cells
- stimulates IL-1 release (fever)
5. dermonecrotic toxin
- causes ischemic necrosis
6. endotoxin-LPS
45
What are the FOUR main B. pertussis adhesins?
**1. Pertactin-surface protein (Pn)
**2. filamentous hemagglutinin (Fha)
[1 & 2 both a. contain arg-gly-asp sequence promoting binding to integrins on ciliated, respiratory cells b. bind to CR3-glycoprotein on macrophages that promotes phagocytosis without respiratory burst-->promotes intracellular survival]
3. Pertussin toxin
-S2 (binding) subunit binds to glycolipid on ciliated cells
-S3 binds to receptors on phagocytic cells--> expression of CR3 on surface
4. Pili
46
the 411 on Pertussis Toxin (PT)
| alpha and beta subunits, S1-5=MAJOR VIRULENCE FACTOR
AB subunit: A-S1 enzymatic, B-S2-S5 binding
A: ADP-ribosylation of regulatory G protein
-prevents inactivation of adenylate cyclase
-*biologic effects: increased respiratory secretions and mucus production; lymphocytosis
B: S3 binds to receptors on phagocytic cells--> expression of CR3 on surface
47
B. pertussis: adenylate cyclase toxin
* *-increase cAMP levels in cells
- affects leukocyte functions in vitro
- --chemotaxis
- --superoxide production
- mucus production
48
What is the epidemiology of B. pertussis: who/why/where?
- HIGHLY infectious airborne droplets
- unrecognized in a dults (dont get severe classic symptoms that a child would get)=RESERVOIR
- decreased immunization-->increased incidence (age 5-14 has show the largest mark of increase)
49
Pathogenesis of B. pertussis
1. A
2. TED
3. **PT: system, mucus, cough, lymph
1. attach to ciliated cells by adhesins
2. tracheal cytotoxin (TCT, cell wall fragments) and others destroy ciliated cells
3. PT-systematic manifestations, mucus production, cough, lymphocytosis
* *4. B. pertussis does NOT invade respiratory tract cells
50
FOUR phases of the 100-day cough (I-CPC)
1. Incubation (7-10days), no symptoms
2. Catarrhal (1-2wks); peak of bacterial culture.
symptoms: rhinorrhea (lots of mucus in sinus cavity), malaise, fever, sneezing, anorexia
3. Paroxysmal (2-4wks)
symptoms: repetitive cough with whoops, vomiting, leukocytosis
4. Convalescent (3-4wks/longer)
symptoms: diminished paroxysmal cough, development of secondary complications (pneumonia, seizures, encephalopathy)
BONUS: overall progression
flu-like--> COUGH --> (complications) pneumonia, CNS
51
What is the lab diagnosis of B. pertussis?
1. Lymphocytosis
2. Sample-nasopharyngeal aspirate
3. Charcoal blood agar
- strict aerove, non-motile
- difficult and slow to grow
- early-higher yield
4. Antigen detection-direct immunofluorescence
* *5. PCR (now standard)
52
How do you treat B. pertussin?
A. **Azithro (other macrolides)-may be effective in early dz
-alternate: Tremethoprim/sulfamethoxazole
-effective in catarrhal stage only
**eliminates nasopharyngeal organisms and prevents spread
B. Supportive care.
53
How do you prevent B. pertussis?
1. DTap Vaccines
- purified, detoxified PT, Fha, Pn and Fim types 2 and 3
- recommended for all infants/children
2. Replace killed whole cell vaccines
3. Tdap recommended for all adolescents/adults
- takes place of one routine Td (every 10 yrs)
