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29 Cards in this Set
- Front
- Back
Neisseria is the only pathogenic bacteria that is? |
Gram-negative cocci, and more precise diplococci
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Neiseria meningitidis virulence factors include?
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Endotoxin (LPS) (petechiae and sepsis); IgA protease (cleaves IgA); pili (undergoes antigenic variation); leeches iron; capsule (antiphagocytic)
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What are the high risk groups for infection with N. meningitidis?
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Infants aged 6 months - 2 years (infants will not manufacture ABs for a few years); and army recruits.
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N. meningitidis usually spreads?
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Via respiratory secretions
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N. meningitidis can live asymptomatically in?
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Nasopharynx epithelium
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N. meningitids can cause?
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Waterhouse-Friderischsen syndrome; meningococcemia with petechial rash; and meningitis
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Most common form of N. meningitidis?
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Meningitis, usually striking infants less than one year of age.
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What is meningococcemia?
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Intravascular multiplication of N. meningitidis resulting in spiking fevers, chills, arthralgia, muscle pain, and petechial rash.
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How do you diagnosis N. meningitidis?
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Gram stain of culture from blood, CSF, or petechial scrapings.
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What blood agar does N. meningitidis grow on?
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Thayer-Martin VPN. Blood agar that is heated (turns brown, AKA chocolate agar). V (vancomycin--kills gram positive); P (polymyxin--kills all gram negative other than Neisseria; and N (nystatin--which eliminates fungi).
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How can you differentiate between the two Neisseria in culture?
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N. meningitidis produces acid from maltose metabolism while N. gonorrhoeae cannot
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How do you treat N. meningitids?
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Penicillin G or ceftriaxone. Close contacts with infected PT are treated with rifampin for prophylaxis.
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What are the virulence factors for Neisseria gonorrhoeae?
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Pili (hypervariable a.a. sequences "phase variation"; prevents phagocytosis); protein I (promote invasion into epithelial cells); opa proteins (adherence and invasion into epithelial cells); and gonococcal endotoxin (LPS) (destroys cilia on neighboring cells, allowing the gonoccus to be taken up by endocytosis); and IgA protease
Nath also has: Gonococcal OMPs (e.g., protein I) that protects against phagocytosis and protein I interferes with neutrophil degranulation. Cell-wall lipo-oligosaccharide (LOS) and OMP contribute to virulence. OMP = outer membrane proteins. |
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N. gonorrhoeae in men? And what are some possible complications?
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Urethritis, painful urination with purulent urethral discharge. Possible complications include: epididymitis, prostatitis, and urethral strictures. There can also be rectal gonococcal infection with anal pruritis, tenesmus, and/or rectal bleeding and purulent discharge.
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N. gonorrhoeae in women?
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Urethritis (most likely asymptomatic), painful burning minimal urethral discharge, cervicitis with purulent exudate, lower abdominal discomfort, painful intercourse (dyspareunia).
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What are some possible complications from N. gonorrhoeae in women?
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Infection to the cervix can produce pelvic inflammatory disease: infection in the uterus (endometritis), fallopian tubes (salpingitis), and/or ovaries (oophoritis). PTs may present with abnormal menstrual bleeding, cervical motion tenderness.
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What increases the risk of pelvic inflammatory disease?
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Menstruation (allows bacteria to spread to cervix, and often symptomatic within one week after menstruation) and presence of of an intrauterine device.
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What are complications of pelvic inflammatory disease?
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Sterility (scaring of fallopian tubes); ectopic pregnancy (scaring of fallopian tubes); abscesses; peritoniitis; and Fitz-Hugh-Curtis syndrome (infection of the liver capsule)
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Rarely, N. gonococcal will invade the blood stream. If so, what happens?
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May collect in the synovial fluid, and cause septic arthritis. This is the most common cause of septic arthritis in sexually active people.
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What does N. gonococcal grow on?
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Thayer-Martin media
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How do you treat N. gonorrhoeae?
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Ceftriaxone (+ doxycycline or azithromycin for probable concurrent Chlamydia infection)
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In neonates, what can N. gonorrhoeae cause?
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Opthalmia neonatorum, a risk for blindness.
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Moraxella catarrhalis can cause?
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Otitis media and upper respiratory infection in PTs with COPD or in the elderly.
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Kingella kingae can cause?
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Frequently colonizes the throat of the young and cause septic arthritis and osteomyelitis in children. In children and adults, can cause endocarditis of native and prosthetic valves.
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How do you diagnosis N. gonorrhoeae?
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Multiple pairs of bean-shaped, Gram-negative diplococci within a neutrophil in a Gram smear of urethral discharge.
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N. gonorrhoeae do not have?
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A polysaccharide capsule, but a pili. This prevents phagocytosis.
They have a capsule. |
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All Neisseria are?
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Oxidase positive
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How do you tell Neisseria gonorrhoeae from N. meningitidis?
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Gonorrhoeae is glucose oxidizer only.
Meningitids is maltose and glucose oxidizer. |
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N. gonorrhoeae is strictly a?
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Human pathogen, with asymptomatic carriers being the largest reservoir.
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