Chapter 11: Haemophilus, Bordetella, and LEgionella

Question 1

why are these 3 grouped togeteher

Answer 1

becasue of common acquisition via the human respiratory tract

Question 2

haemophilus influenzae what does name mean

Answer 2

haemophilus means blood loving, needs hematin in blood for bacteriums cytochrome system and needs bloods NAD+ for metabolic activity

Question 3

what does haemophilus influenzae attach

Answer 3

lungs of persons debilitated by viral influenza infection

Question 4

virulence of haemophilus influenzae

Answer 4

polysaccharide capsule (b subtype most common with invasive disease)
-meningitis, epiglottitis, septic arthritis

nonencapsulated (nontypeable) strains can colonize upper resp tract but only cause local infection

otitis media in children and resp disease in adults weakened by preexisting lung disease

Question 5

pts with COPD get frequent infections with what type of H influenzae

Answer 5

nontypeable which makes symptoms worse

Question 6

what age are children most susceptible to h influenzae

Answer 6

6 months and 3 years old

Question 7

what is the most serous infection caused by haemophilus influenza type b

Answer 7

meningitis: in children from 6 months to 3 years old
inhalation to get in then goes to LNs and blood stream where it penetrates meninges

symptoms are non specific: fever, vomiting, altered mental status

-treat with antibiotics lipid A gets released and can cause neurological effects

Question 8

3 bacteria respnsible for most meningitis acquired by baby coming out of the birth canal

Answer 8

LESB

listeria monocytogenes
E coli
Streptococcus Group B

Question 9

2 bacteria responsible for meningitis later on in life after maternal Abs worn off

Answer 9

new hampshire

Neisseria meningitides
Haemophilius influenzae

Question 10

haemophilus infulenzae type b diseases causdd

Answer 10

meningitis
acute epiglottitis
septic arthritis
sepsis

Haemos are influenced to go to MASS

Question 11

actue epiglottitis and haem influenaze b

Answer 11

large red epiglottis looks like a red cherry at base of tongue
excessive saliva will drool out of child’s mouth as they will not be able to swallow

Question 12

sepsis and haem influenzae b

Answer 12

children btwn 6 months and 3 years present with
fever, lethargy, loss of appetite, and no evidence of localized disease

-bacteria invade blood stream via upper respiratory tract

Question 13

septic arthritis and haem influenzae b

Answer 13

most common cause of septic arthritis in infants

Question 14

role of vaccine for haem influenzae b

Answer 14

first vaccine hase purified b capsule can only be effective to children over 18 months

current vaccines have h influenzae capsule PRP conjugated with mutant diphtheria toxin protein, neisseria meningitides outer membrane protein, or tetanus toxoid
-activates T lymphocytes and Abs against b capsule antigens

vaccination with the Hib capsule

Question 15

haemophilus ducreyi is responsible for

Answer 15

STD: chancroid

• painful genital ulcer
• unilateral painful swollen inguinal LNs rapidly develop in 1/2 of infected persons

haemos do cry when they get chancroid

Question 16

differential diagnosis with haemophilius ducreyi

Answer 16

syphilis: ulcer is painless, bilateral, non-suppurative
herpes: lesions start as blisters but when break they are painful, usually have systemic symptoms like myalgias and fever (unlike chancroid)

lymphogranuloma venereum (chlamydia trachomatis)

• painless matted suppurative inguinal LNs that develop slower than chancroid
• primary ulcer disappears before nodes enlarge (coexist in chancroid)

Question 17

gardnerella vaginalis

• causes what
• symptoms

Answer 17

causes bacterial vaginitis
burning or itching of labia
buring o on urination
copious foul smelling vaginal discharge that has fishy odor

Question 18

how can gardnerella vaginalis be differentiated from other causes of vaginitis

Answer 18

(candida or trichomonas)

• examine slide of vaginal discharge for presence of clue cells
• tiny pleomorphic bacilli within cytoplasm

Question 19

bordetella pertussis causes

-what kind of bacteria is it

Answer 19

whooping caugh

-gram neg rod

Question 20

4 virulence factors of bordetella pertussis

Answer 20

pertussis toxin:
extra cytoplasmic adenylate cyclase
FHA
tracheal cytotoxin

Question 21

bordetella pertussis: pertussis toxin

Answer 21

• B subunit binds target cell, A subunit activates cell membrane bound G reg proetins which in turn activate adenylate cyclase = increased cAMP
• causes: histamine sensitization, increased insulin syn, promotion of lymphocyte production and inhibition of phagocytosis

Question 22

b pertussis: extra cytoplasmic adenylate cyclase

Answer 22

these are swallowed by host neutrophils, lymphocytes, and monocytes

-increases cAMP inside these cells, and causes impaired chemotaxis and impaired generation of h202 and superoxide

Question 23

b pertussis: FHA

Answer 23

pili rod involved in binding to ciliated epithelial cells of bronchi

Question 24

b pertussis: tracheal cytotoxin

Answer 24

destorys ciliated epithelial cells = impaired clearance of bacteria, mucus

-responsible for violent cough

Question 25

most cases of whooping cough are seen in what population

Answer 25

adolescents and adults

-booster vaccination in adults ages 19-64

Question 26

whooping cough is highly contagious with transmission occuring via respiratory secretions on the hands or in aerosolized form. week long incubation followed by 3 stages of disease:

Answer 26

1) catarrhal stage: 1-2 weeks, similar to URI, most contagious period

2) paroxysmal stage: fever gone, nonprodcutive cough develops
- very forceful attacks, with inspiratory gasp though narrowed glottis after (whoop)
- pt can become hypoxemic during this burst of cough
- vomiting can often follow attack
- last a month or longer
- most severe in the young

3) vonvalescent stage: attacks less frequent over a month, patient no longer contagious

Question 27

b pertussis and lympocytes and neutrophils

Answer 27

increase in lymphocyte count with just a modest increase in neutrophils (looks more like viral picture)

Question 28

specimens for B pertussis colloceted how

Answer 28

collected from posterior pharynx with a calcium alginate swab, then put on bordet gengou medium

Question 29

vaccine for b pertussis

Answer 29

DTaP vaccine

Question 30

legionella pneumophila what kind of bacteria

• loves what
• like mycobacterium tuberculosis it is a what parasite

Answer 30

aerobic G- rod, small and difficult to visualize on a gram stain

• water lover
• facultative intracellular parasite that settles in lower respiratory tract and eaten by macrohpges

Question 31

2 interesting and unusual things about legionella

Answer 31

facultative intracellular parasite for free living amoebas
-multiplies a thousand fold within these, and when amoebas face hardship it is protected

can enter low metabolic state and survive in biofilm
-disruption of biofilm can cause massive release of it into water

Question 32

legionella is responsible for what diseases

Answer 32

pontiac fever: headache, muscle aches, fatigue, fever and chills (can be in air conditioning)

legionnaires disease: pts develop very high fevers and severe pneumonia

Question 33

legionnaires disease unusual clinical elements

Answer 33

high fever, low heart rate
severe headache
confusion
myalgia (sometimes with increased serum CPK and myoglobinuria)
cough
hyponatremia
hypophosphatemia
elevated AST and ALT
diarrhea
abdominal pain