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 (-)
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.
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.
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
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”
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
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
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
Neisseria meningitides
Treatment
A Shocking Death on Campus
3rd generation cephalosporin
-ceftriaxone
Close contacts (>8 hrs over 7 days prior) will need:
-rifampin
Neisseria gonorrhea
MOA
The Violinists last Clap
STI
NOT encapsulated
Facultative intracellular
Invade PMN’s
(Polymorphonuclear leukocytes; Neutrophils, eosinophils, and basophils)
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
Neisseria gonorrhea
Treatment
The Violinists last Clap
3rd generation cephalosporin
-ceftriaxone
Treat for chlamydia coinfection
-macrolide Zpack
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
