Neisseria & Moraxella Flashcards
(34 cards)
Neisseria Genus info
- N. Gonorrhoeae & Meningitidis = Obligate Pathogens
- Others are Apathogenic normal flora members in Nasopharynx or Urogenital tract (opportunistic)
Neisseria Genus Morphology
- Gram Negative
- Diplococci
- Pyogenic (pus forming)
Apathogenic Neisseria Examples
- N. Flava (np)
- N. Per/Subflava (np)
- N. Mucosa (np)
- N. Elongata (urogenital mucosa)
N. Meningitidis General info
- Facultative I.C Pathogen
- 1-5% of population carries it
- Colonizes Nasopharynx
- Spread by respiratory droplets (crowds)
N. Meningitidis Morphology
- Gram Negative
- Bean shaped Diplococci
- Encapsulated (polysaccharide)
N. Meningitidis Cultivation
- Can grow on Blood agar + 5-10% CO2
- Ferments Glucose & Maltose
- Cultivated on Chocolate agar
- Can be stained by Methylene Blue
N. Meningitidis Non-toxic Virulence factors
- Polysaccharide Capsule: 6 serogroups A, B, C, W-135, X, Y
- Pili & Fimbriae
- Opa OM proteins like Adhesins
- IgA Protease
N. Meningitidis Toxic Virulence factors
Lipooligosaccharide (LOS)
- Endotoxin effect
- Strong Inflammatory cascade
- Can lead to leaky capillaries, sepsis, & shock
N. Meningitidis Diseases
- Bacteremia = Miningococcemia
- Sepsis & Shock when LOS binds TLR4
- Waterhouse-Friderichsen syndrome
- Petechial Rash
- Purulent Meningitis
LOS on TLR4 causes what
TLR4 is on immune cells
- Vasodilation & Hypotension
- Fever
- Disseminated Intravascular Coagulation (DIC)
Meningitis Triad
- High Fever
- Headache
- Neck stiffness
(brudzinski’s neck sign)
N. Meningitidis Treatment
- Ceftriaxone (cross BBB) & Vancomycin
- Prophylaxis using Rifampicin or Ciprofloxacin
N. Meningitidis Vaccines
- Tetravalent Polysaccharide Vaccine = A, C, W-135, Y serotypes
- Meningococcal B Vaccine (recombinant proteins)
N. Meningitidis Microbiological Diagnosis
- CSF specimen through Lumbar puncture
- Cloudy, Purulent CSF
- Latex agglutination of Antigens of capsule (rapid)
N. Gonorrhoeae General info
- Colonizes genital tract
- Spreads directly with mucosal surfaces (sexual contact)
- Can Spread vertically from mother to child
- STD/STI
N. Gonorrhoeae Morphology
- Gram Negative
- Diplococci
- Non-encapsulated!
- Facultative I.C in PMN leukocytes
N. Gonorrhoeae Cultivation
- Fastidious bacteria
- Rich nutrients, temperature
- Thayer Martin agar
- Ferments Glucose only, not maltose
Thayer Martin Agar
Chocolate agar with anti-microbials to inhibit other growths:
- Vancomycin
- Colistin (polymixin)
- Nystatin (anti-fungal)
- Trimethoprim
N. Gonorrhoeae Non-toxic Virulence Factors
- Pilli & Fimbriae
- Opa OM proteins (adhesins)
- IgA Protease
N. Gonorrhoeae Toxic Virulence Factors
LOS endotoxin leads to strong inflammatory cascade
N. Gonorrhoeae Diseases
- Gonorrhea
- Opthalmoblenorrhoae Neonatorum (conjunctivitis after birth)
- Proctitis (anus/rectum)
Gonorrhea Men
- Urethritis (purulent)
- Bonjour droplets discharge
- Dysuria (pain)
- Epididymitis, Prostatitis, Orchitis
Gonorrhea Women
- Cervicitis
- Discharge, Dysuria, Abdominal pain
- Dyspareuria (pain during sex)
- PID (pelvic inf. disease)
- PID can cause Fitz Hugh Curtis Syndrome = infertility (liver violin adhesions)
- Oral Gonorrhea from oral sex
N. Gonorrhoeae Treatment
- Ceftriaxone
- Azithromycin (macrolide) / Spectinomycin given as Co-infection treatment for Chlamydia
