Module 11 Flashcards
***** which of these are bacterial infections for which there are NO vaccines?
a - mycobacterium tuberculosis
b - corneybacterium diptheria
c - staphylococcus aureua
d - streptococcus pneumoniae
e - streptococcus pyogenes
f - C & E
f - C & E
what is the genus Neisseria a pathogen of
respiratory & genital tracts
members of the genus neisseria are __
Gram - diplococci
T/F humans are the only known reservoir for Neisseria pathogens
true
are neisseria pathogens catalase positive or negative
positive –> obligate aerobes
what are the main species of the Neisseria genus
- N. meningitidis (meningitis)
- N. gonorrhoeae (gonorrhea)
what is closely related to Neisseria and is the normal flora of the upper respiratory tract
Moraxella catarrhalis
which neisseria pathogen can go septic increasing the inflammation throughout the body
meningitidis
which neisseria pathogen is only able to inhabit mucosal surfaces
gonorrhoeae
what is important in the transmission of neisseria pathogens
the carrier state
what is the susceptible age group for N. meningitidis
15 - 24
how is N. meningitidis transmitted
large respiratory droplets in close range
what is the significant morality rate of N. meningitidis
10-15% even w/ antibiotics
after _ days in the carrier phase the disease state either stops as a _ or transitions to _ or _
- 10
- minor carrier
- sepsis / meningo-sepsis
- meningitis residing in the spinal cord
how is gonorrhea transmitted
spread ONLY by direct genital contact attaching to epithelial cells in the urethra and cervix and remains localized
what are the symptoms of N. gonorrhea
inflammation, yellow discharge, pelvic inflammatory disease (PID)
what does N. gonorrhea have drug resistance to
beta-lactams & tetracyclines
how is N. gonorrhea diagnosed
Gram stain –> Gram - diplococcus
what is the spread of large numbers of N. meningitidis in the bloodstream via lymphatic system causing sepsis and LPS/LOS endotxoin shock
meningococcemia
how does meningococcemia proceed to meningitis
inflammation spreads to the meninges via choroid plexus
what are the neurological defects that meningitis can cause
- neuromotor disabilities
- seizure disorders
- learning difficulties
what are the virulence factors of N. meningitidis
- variant LPS in cell envelope (no O-antigen)
- endotoxins that are cytotoxic
- pili (fimbriae)
- exo-enzymes (IgA1 protease)
what virulence factor is used for the N. meningitidis vaccine
the polysaccharide capsule
what is the function of IgA1
protect against IgA1 on mucosal surfaces and aids in colonization
what are the treatment options for N. meningitidis infections
- antibiotics (Penicllin G, but typically not enough on is own)
- steroids (reduces inflammation)
___ has the largest problem with bacterial A strains of N. meningitidis
africa
what do all Gram - bacteria release
‘blebs’ or outer membrane vesicles
how do you prevent N. menigitidis
vaccines
what are the vaccines for N. meningitidis
- A/C/Y/W-135 (Menomune)
- ‘B’ strain
- ACY/W conjugate vaccine (Menactra)
- 4CMenB
Menomunes use was restricted to to
military
Menomune works well in __ but has no response in ___
adults, children < 2 years old
how does ACY/W vaccine Menomune work
purified capsule polysaccharide
how does ACY/W Conjugate vaccine Menactra work
purified capsule polysaccharide conjugated to protein (diptheria toxoid)
the US now sees mostly type __ strains of N. meningitidis
B
what is the appearance of the haemophilus genus
small Gram - coccobacilli
Haemophilus are a a major part of the normal flora of the __
URT
how does H. influenzae spread
via inhalation of airborne droplets, shared secretions, etc.
non-invasive infections usually originate from __
existing normal flora strains of H. influenzae that do NOT have a capsule
what are infections that H. influenzae can cause
- sinusitis
- pink eye
- pneumonia
what are invasive infections that H. influenzae can cause
- septicemia
- meningitis
what are the symptoms and syndromes of septicemia
- disseminated intravascular coagulation (DIC)
- septic shock
- death
what are H. influenzaes virulence factors
- cellular envelope w/ LPS (LOS) no O-antigen
- endotoxin
- cytotoxic
- inflammatory
- capsule
- exoenzymes (IgA protease)
what is the first conjugate vaccine for H. influenzae
type b capsule covalently linked to a protein (diphtheria toxoid & tetanus toxoid)
why are these pathogens considered “triplets”
respiratory, encapsulated –> bloodstream –> meningitis
