fastidious bacteria Flashcards
picky eaters
fastidious bacteria
what causes whooping cough
bordetella pertussis
leading cause of vaccine preventable illness in the US
bordetella pertussis
bordetella pertussis is a obligate aerobe or anaerobe
aerobe human pathogen that is highly contagious
bordetella pertussis grows in what media?
charcoal-cephalexin blood agar
with B. pertussis what do we need to do after a culture has been collected and isolated?
treat before culture grows up due to highly contagious and you want to limit the spread of the disease
treatment of B. pertussis
azitrhomycin (microlide)
3 phases of infection for B.pertussis
- catarrhal
- paroxysmal
- convalescent
People withpertussisare most infectious during the ________ periodand during the first two weeks after onset of the cough
catarrhal
diagnostic test for pertussis
PCR and culture (regan-lowe)
B. pertussis establishing infection: (2)
- attachment- ciliary cell in lungs
2. secretion of toxins- inhibits functions of cilia and intereferes with immune response
B. pertussis toxin
A-B toxin: Lymphocytosis-promoting factor: inhibits lymphocytes from entering tissues
B. pertussis secretes another toxin called adenylate cyclase toxin (ACT) which
produces cAMP
Disables innate immune cells; prevents leukocytosis
TCT toxin from pertussis
cell wall fragment kills ciliated cells
attachment of B. pertussis (3)
- FHA
- Fimbriae
- Pertactin
DTwP (DTP)
whole killed B. pertussis- long lasting immunity side effects associated
DTaP
acellular B. pertussis- immunity wanes after 5 years
** vaccinated individuals are asymptomatic carriers
TdaP
acellular B. pertussis low levels of diptheria and tetanus toxoid
patient population most affected
infants most at risk and then adolescents since immunity wanes
prevention of B. pertussis
prophylactic azithromycin for contacts
vaccines for meningitis targets ______ and thus antigenic variation is an issue
capsules
meningitis is transmitted by
respiratory droplets
N. meningitidis and H.influenzae are nl. constituents of upper resp, tract
yep, it is only when it get in the blood=sepsis and/or meninges=meningitis
N. meningitidis and H.influenzae grow in what agar?
chocolate agar (thayer-martin)
Penicillin can cross blood-brain barrier when compromised during meningitis
yep
only gram negative diplococci
N. meningitidis that is part of the normal flora that colonizes mucosal membrane
what type of rash do we see in meningococcal disease?
purple rash- petechial rash
with meningococcemia, entry into blood causes a
massive inflammatory response due to LOS (lipooligosaccharide) which is highly pro0inflammatory
adrenal hemorrhage caused by attempt to maintain blood pressure; septic shock
Waterhouse-Friderichsen syndrome
N. meningitidis has IgA Protease and a Polysaccharide Capsule –
inactivates secretory IgA, inhibits immune responses (like N. gonorrhoeae) and anti-phagocytic
recombinant vaccine (N. meningitidis )
against 4 proteins made by serotype B
Hard to develop high affinity antibodies against capsular antigens that are induced by memory responses
so true, so so true
treatment for N. meningitidis
- Ceftriaxone (IV – cephalosporin with excellent CSF penetration); penicillin also works. Prompt treatment if disseminated.
- Rifampin prohylaxis – close contacts.
H. influenzae has ____ serotypes but type ___ is the most common
***part of normal flora of nasopharynx
6 serotypes but type B is the most common
capsular vaccine
does not work in small children and low memory response for both H. influenzae and N. meningitidis
HiB
conjugate vaccine for H. influenzae
H. influenzae clinical features
- epiglottitis
- pneumonia
- otitis media- use penicillin to tx.
H. pyloric is a ____ rod which allows them to dive into the mucosa and it is also a microaerophilic ( microorganism that requires oxygen to survive, but requires environments containing lower levels of oxygen than that are present in the atmosphere)
flagellated
H. pyloric makes what
urease which raises pH and allows the H. pylori to penetrate into stomach epithelium
H. pyloric secretion of virulence factors:
- ______: vacuolating toxin –disrupts epithelial cells…PMNs…ulcers
- ______: assoc. with stomach cancer – disrupts cell signaling
- Proteases:
HtrA disrupts cell-cell junctions
_____________ - generates NH3 and causes cell death (ass. with cancer)
- VacA: vacuolating toxin –disrupts epithelial cells…PMNs…ulcers
- CagA: assoc. with stomach cancer – disrupts cell signaling
- Proteases:
HtrA disrupts cell-cell junctions
Glutamyl-transpeptidase - generates NH3 and causes cell death (ass. with cancer)
H. pylori increases risk for cancer… why?
chornic inflammation increases risk
treatment for H. pylori
triple threat threapy tx.:
- PPP- decrease acidity
- amoxicillin
- clarithromycin (macrolide)
Individuals infected withH. pylorihave a 10 to 20% lifetime risk of __________and a 1 to 2% risk of acquiringstomach cancer
Individuals infected withH. pylorihave a 10 to 20% lifetime risk of developingpeptic ulcersand a 1 to 2% risk of acquiringstomach cancer
