-
what are the common traits of neisseria
- aerobic
- g (-)
- diplococci
- oxidase (+)
- catalase (+)
- non motile
-
where do non-pathogenic species of neisseria colonize
oropharynx, nasopharynx, anogenital mucosal membrane
-
what are the pathogenic neisseria
- n. meningiditis (meningococci)
- n. gonorrheae (gonococci)
-
meningococci colonizes
commensal in nasopharynx of healthy people
-
can n. meningiditis grow on blood agar or chocolate agar
- grows on blood agar
- grows on chocolate agar
-
is N. gonorrhoeae part of the normal healthy microbiome?
no
-
can gonococci grow on blood agar or chocolate agar
- cannot grow on blood agar
- can grow on chocolate agar
-
gonococci has what type of growth
fastidious growth
-
-
gonococci does/does not have a capsule
no capsule, but has a surface charge
-
n. meningitidis does/does not have a polysaccharide capsule
- capsule present
- used for serotyping
- virulence factor
-
pathogenic and non pathogenic strains of neisseria both have what kind of virulence factor
pili
-
what is clinically significant about reinfection of n. gonorrheae
does not have a capsule, so it is non immunogenic. Therefore people can be infected with the same strain over and over again
-
what are the types of proteins on the neisseria outer membrane
- porin proteins: facilitates invasion, protects bacteria from immune response
- opa protens (opacity): cell to cell signaling
- rmp proteins (reduction modifiable): protect surface antigens on abcterial cells from recognition by bactericidal antibodies
-
what are the types of porin proteins and what bacteria expresses them
- PorA: expressed in N. meningiditis
- PorB: expressed in N. Gonorrheae and N. meningiditis
-
what type of lipid is found in neisseria bacterial surface
- lipooligosaccharide (LOS): distinct from LPS gram (-) bacteria
- endotoxin activity
- coats outer membrane that are released during rapid cell growth
-
both N. meningiditis and N. gonorrheae produce what type of enzyme
immunoglobin (Ig) A1 protease which cleaves antibodies, inactivating them
-
what are the virulence factors of neisseria
- pilin
- por proteins
- opa protein
- rmp protein
- transferrin binding protein, lactoferrin binding protein, hemoglobin binding protein
- lipooligosaccharide (LOS)
- IgA1 protease
- B-lactamase
-
what is the function of transferrin binding protein
facilitates collection of iron for bacterial metabolism
-
what is the functo=ion of B-lactamase
hydrolyzes b-lactam ring in antibiotics, inactivating it
-
what causes most symptoms of gonococcal disease
immune response when gonococcal LOS stimulates release of TNF-a from immune cells
-
what is the reservoir for n. gonorrheae and how is it transmitted
- found in only humans
- asymptomatic carriers
- sexual contact
-
where is the primary genital infection for men and women infected with gonorrhea
- men: in urethra, purulent discharge and dysuria
- women: in cervix, organism cannot infect vagina, dysuria,
-
what is gonococcemia
infection of skin and joints with septicemia
-
what are the clinical diseases of N.gonorrheae
- gonorrhea
- gonococcemia
- perihepatitis
- purulent conjunctivitis
- anorectal gonorrhea
- pharyngitis
-
what is the pathogenesis of neisseria meningitidis
- meningococci attach specifically to receptors on non ciliated cells
- meningococci are internalized in phagocytic vesicles
- LOS endotoxin causes vascular damage
-
what is the reservoir for n. meningitidis
only humans
-
how is n. meningitidis transmitted by respiratory droplets
- transmitted between people in prolonged close contact
- respiratory contact
- epidemic spread along meningitis belt of sub saharan africa
-
what are the diseases caused by n. meningitidis
- meningitis
- meningococcemia
- pneumonia
- arthritis
-
what are the meningeal signs of meningitis
- sensitivity to light
- brudzinski sign
- kernig's sign
-
what is the mortality rate of untreated and treated meningococcal induced menigitis
- untreated: 100%
- treated: 10%
-
describe meningococcemia
- septicemia with or without meningitis
- life threatening
- thrombosis
- DIC
- small skin lesions that may progress to large hemorrhagic lesions
-
how is meningococcemia and pneumonia induced n. meningitidis treated
antibiotic therapy
-
what is the laboratory significance of gonococci gram stain
- very sensitive to detect gonococcal infection in men and purulent urethritis
- can be found inside and outside neutrophils from urethral swab
- insensitive in detecting gonoccocalÂ
- useful for purulent arthritis
- insensitive for gonococcal skin lesions
-
what is the laboratory significance of meningococci
- readily detected in CSF
- can be seen in blood in patients with overwhelming meningococcal disease
-
what is PCR used to to detect what type of neisseria
n. gonorrhoeae
-
what are the complications from gonococci culture
- gonococci die rapidly if allowed to dry or exposed to cool temperatures
- blood culture media can be toxic to gonococci
- grows on chocolate agar
- grows on thayer martin
-
what are the complications from meningococci culture
- easily recovered than gonococci
- specimens responsible for disseminated disease virulent and must be handled with care
-
what is the treatment for n. gonorrhoeae
- dual antibiotic therapy
- no vaccine for it
- re-infection is common
-
n. meningiditis treatment
- antibiotic treatment
- two tetravalent vaccines in US
- vaccine against meningococcal serotype A
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