Gram (-) cocci Flashcards
Neisseria
Neisseria species overview
lab tests
Noir Series
gram (-) Diplococci
Oxidase (+)
Grows on Chocolate agar
Inhibited on Blood agar
Thayer martin (AKA VPN) is selective agar enriched with vancomycin, polymixin, and nystatin
*Carbohydrate fermentation (+) ddx with Moraxella catarrhalis which is also gram (-) diplococci but is carb ferm (-)
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Neisseria species overview
MOA
Noir Series
MAC defiency
Unable to form the MAC complex due to complex c5-c9 being inhibited, leads to increased Neisseria infections.
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Neisseria species overview
VF
Noir Series
Pilli allow the attachment to surfaces and display antigenic variation
IgA protease will cleave IgA at its hinge point, facilitating survival along mucosal surfaces.
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Neisseria meningitides
lab tests
A Shocking Death on Campus
gram (-) Diplococci
Oxidase (+)
Ferments maltose (Only meningitdes!)
Grows on Chocolate agar
Inhibited on Blood agar
Thayer martin (AKA VPN) is selective agar enriched with vancomycin, polymixin, and nystatin
![](https://s3.amazonaws.com/brainscape-prod/system/cm/243/455/127/a_image_thumb.jpg?1510022995)
Neisseria meningitides
MOA
A Shocking Death on Campus
found in nasal cavity
spreads in crowded areas via r_espiratory droplets_ (military, college dorms, etc)
N. Meningitides invades hemotogenously, leading to massive immune response generated by LOS proteins (lipooligiosaccharides)
-LOS outgrows surface area of bacteria and blebs off, leading to the massive inflammatory response
* think“LOS envelopes caught fire”
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Neisseria meningitides
VF
A Shocking Death on Campus
Polysaccharide Capsule is the major VF
We have vaccine for A,C,D capsules but not B
* Sickle Cell disease more susecptible due to N. meningitides being encapsulated
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Neisseria meningitides
Signs and symptoms
A Shocking Death on Campus
Inflammatory response
hypovolemia
Characteristic petechial rash → thrombocytopenia → DIC (Disseminated Intravascular coagulation)
Capillary leakage → shock
* Waterhouse fritter syndrome; when vasoconstriction goes to max to attempt to maintain BP, and adrenals can infarct contributing to shock
![](https://s3.amazonaws.com/brainscape-prod/system/cm/243/455/133/a_image_thumb.jpg?1510023098)
Neisseria meningitides
Waterhouse fritter syndrome
A Shocking Death on Campus
vasoconstriction goes to max to attempt to maintain BP, and adrenals can infarct contributing to shock
![](https://s3.amazonaws.com/brainscape-prod/system/cm/243/455/134/a_image_thumb.jpg?1510023117)
Neisseria meningitides
Treatment
A Shocking Death on Campus
3rd generation cephalosporin
-ceftriaxone
Close contacts (>8 hrs over 7 days prior) will need:
-rifampin
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Neisseria gonorrhea
MOA
The Violinists last Clap
STI
NOT encapsulated
Facultative intracellular
Invade PMN’s
(Polymorphonuclear leukocytes; Neutrophils, eosinophils, and basophils)
![](https://s3.amazonaws.com/brainscape-prod/system/cm/243/455/136/a_image_thumb.jpg?1510023147)
Neisseria gonorrhea
Signs and symptoms
The Violinists last Clap
Effects genitalia first
May cause Polyarthritis, often in knee and is asymmetric
Males:
causes urethritis, prostatis, and orchiditis
Females:
PID (Pelvic Inflammatory DIsease) → purulent white discharge
Fitz Hugh Curtiss syndrome → Violin string like lesions in liver from spread into peritoneum
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Neisseria gonorrhea
Treatment
The Violinists last Clap
3rd generation cephalosporin
-ceftriaxone
Treat for chlamydia coinfection
-macrolide Zpack
![](https://s3.amazonaws.com/brainscape-prod/system/cm/243/455/138/a_image_thumb.jpg?1510023169)
Neisseria gonorrhea
Delivery / Birth
The Violinists last Clap
Can be passed on to the baby during delivery
N. gonorrhea causes conjunctivitis within 5 days of birth
* vs chlamydia which is usually > 7 days after birth
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