Spirochetes and STDs Flashcards
Trench Mouth
Due to Non-pathogenic species of Treponema and Borrelia, present with anaerobes in Normal Flora.
Necrotizing, Ulcerative infection of Gums,
Oral cavity, or Pharynx.
Spirochetes
Morophology:
- -Spiral
- -Ranges from **Loose Coils to a
- *Right Cockscrew Shape
- -**Peptidoglycan Cell Wall (*Similar to the outer membrane of Gram Negatives)
- -**Motile: **Rotation and **Flexion
- *Darkfield Microscopy
- -**Not isolated in Culture
- -**Aerobic or Anaerobic
Important ones:
- -Leptospira interrogans (Leptospirosis)
- -Borrelia recurrentis (Relapsing Fever)
- -Borrelia burgdoferi (Lyme Disease)
- -Treponema pallidum (Syphilis)
Leptospira interrogans
Spirochete
Leptospirosis
Manifestations:
1st) **Influenza-like Fever (*After 7-13 days)
(Fever subsides after a week, due to disappearance of the microbes from blood)
2nd) **Aseptic Meningitis
(*Lasts 3+ weeks)
(Or may be more generalized muscle aches, rash, biochemical evidence of hepatic and renal involvement, etc.)
3) Weil’s Disease:
- -Most severe case
- -Extensive Vasculitis
- -Hemorrhagic Rash
- -Jaundice
- -Renal damage
Epidemiology:
- -Contaminated water with Animal urine
- -Entry via small skin breaks, conjunctiva, or ingestion.
- -Human-to-Human is *Rare
Diagnosis:
–Serology
–Do Not culture or darkfield.
(culture takes weeks)
Treatment:
–**Penicillin
–*Vaccines for cattle and pets.
(Doxycycline, Ceftriaxone alternatives)
Pathogenesis:
–Spread widely via *Bloodstream to everywhere, including CNS and Kidney (Tubular infection and Interstitial Nephritis)
Borrelia recurrentis
Spirochete
Relapsing Fever
Manifestations: (*After 7 day incubation) --**Fever --**Headache --**Muscle pain (Myalgias) (all last 2-4 days)
Louse-Borne Relapsing Fever: More **Severe
(40% fatal)
Epidemiology:
1) **Epidemic: **Louse-Borne (body lice)
Human-to-Human only b/c Humans are its only host. B. recurrentis is only species of louse-borne relapsing fever.
2) **Endemic: **Tick-Borne
Diagnosis:
–**Giemsa or Wright Stains of blood smears.
During Febrile period
–Don’t do serology.
Treatment:
–**Doxycycline
(Erythromycin, Ceftriaxone alternatives)
Pathogenesis:
- -**Thousands of spirochetes per mL of blood is when manifestations develop.
- -Unknown mechanisms.
Borrelia burgdoferi
Spirochete
Lyme Disease
Manifestations:
1ST STAGE
–**Skin Lesion @ Tick Bite Site: Annular lesion with a **Raised, Red Border + *Central Clearing, forming a *Bull’s Eye Pattern.
As this **Expands, the lesion called **Erythema Migrans forms.
**Skin lesion disappears over Period of Weeks.
- -**Fever
- -**Fatigue
- -**Myalgia
- -**Headache
- -**Joint pain
- -**Mild Neck Stiffness
2ND STAGE
(Days, Weeks, Months after Onset)
–Neurologic: Cranial Nerve Palsies
–Cardiac: AV Block
–Relapsing Arthritis: Chronic, @ Large Joints
(2nd stage resolve completely in weeks. Relapsing Arthritis is most persistent and most likely to become Chronic. Develops in 2/3 untreated patients.)
Epidemiology:
–Tick –> *Mouse –> *Deer Cycle
–Rodents are primary reservoir.
–Infection is transmitted by *lxodes Ticks in wooded habitat.
–**Disease does not occur in areas where Deer are not abundant.
(B/c Deer are essential for mating and survival of tick)
Diagnosis:
- -**Clinical findings
- -**Epidemiological history
- -*PCR detect their DNA, but is *Not Specific enough.
- -*Don’t do Serology.
Treatment:
–**Doxycycline and **Amoxicillin
for 30-60 days
–IV Ceftriaxone or Pencillin G for **Neurologic or Cardiovascular.
–**Response to treatment is typically slow.
–**Vaccine is no longer available.
Pathogenesis:
- -**Down-regulates immune response
- -**Surface proteins of Burgdoferi bind to *Fibronectin and Factor H to interfere with *Complement Deposition.
Treponema pallidum
Spirochete
Syphilis
Manifestations:
1) Primary Syphilis: Infectious!!
- **Painless Ulcer (Chancre) @ infection site: external genitalia, cervix, oral area.
- -Appears @ 3 weeks.
- -Spontaneously heals after 4-6 weeks.
- -*Enlarged Regional Lymph Nodes within 1 week; may persist for months.
–**Endarteritis: –> leads to **Necrotic Ulceration of Primary Lesion with *Dense Granulomatous Cuffs of Lymphocytes, Monocytes, and Plasma cells surrounding vessels.
2) Secondary Syphilis:
* Infectious!!
- -@ 2-8 weeks After Appearance of Chancre
- -Symmetric Mucocutaneous Rash @ Trunk and Extremities
* Lymphadenopathy
- -Resolve Spontaneously after few days or many weeks.
- -1/3 Patients may develop Painless Mucosal Warty Erosions (Condylomata Latum) @ Genitals
3) Latent Syphilis
* *Infectious!! via relapsing secondary lesions or by blood or transfusion.
- -Asymptomatic
- -Positive Serology
4) Tertiary Syphilis:
* *Non-infectious!!
- -**15-20 years After infection
- -Localized *Granulomatous Reaction: **Gumma @ Skin, bones, joints, other organs.
NeuroSyphilis (Tertiary):
–Chronic Meningitis: Degenerative Parenchymal Changes (Demyelination, etc.)
Peripheral Neuropathies due to demyelination in Spinal Cord (Tabes dorsalis)
–Psychosis
–Pareses:
Personality
Affect
Reflexes
Eyes
Sensorium
Intellect
Speech
- *Cardiovascular Syphilis (Tertiary):
- -*Aneurysms
- -and/or **Aortic Valve Incompetence
Expanding aneurysm can cause *Pressure Necrosis of adjacent structures or *Rupture
Congenital Syphilis:
- -**Rhinitis
- -**Maculopapular Rash
- -**Bone Changes: *Saddle Nose, *Saber Shins)
- -Terminal:
- Anemia, *Thrombocytopenia,
- Liver Failure
- -Untreated maternal infection can cause this or Miscarriage.
Epidemiology:
- -**Direct Sexual Contact from *Primary or *Secondary Syphilitic Lesions.
- -**Needle sharing
- -**Transplacental to Fetus
- -**Tertiary Syphilis is NON-Infectious.
Diagnosis: --**Darkfield Microscopy --Direct Fluorescent Antibody --Serology: Antibody remains in body, even after treatment, so will always have positive antibody test
(1) **Nontreponemal Test: Reagin Antibody against *Cardiolipin, a lipid complex, is used.
*Nonspecific, but good for screening and monitoring treatment b/c is *Sensitive and *Low cost.
*Lipid material is released from damaged host cells early in infection.
Most common tests for this are
Rapid Plasma Reagin (RPR) and
Venereal Disease Research Lab (VDRL).
(2)**Treponemal Test:
Antibody against T. pallidum, such as
Fluorescent Treponemal Antibody (*FTA-ABS).
**Specific!
Treatment:
- -**Penicillin
- -Doxycycline as alternative (but toxic to fetus)
Pathogenesis:
–**Spreads to Bloodstream Within Minutes from primary site.
Immunity:
- -Immunity to reinfection (1/3 patients). Doesn’t appear **Until Early Latency.
- -Antibodies to *Treponemal Outer Membrane Proteins (OMPs) are seen with immunity (resistance to reinfection)
Neisseria gonorrhoeae
Gonorrhea
Manifestations: 1) *Urethritis (Men) (*2-7 days after infection) --Purulent Urethral Discharge --Dysuria --Local spread can lead to *Epididymitis or *Prostatitis.
MSM: Rectal infection
2) *Endocervicitis (Women) (50% asymptomatic) --Vaginal Discharge --Urinary Frequency --Dysuria --Abdominal pain --Menstrual abnormalities
3) Transmission @ Birth:
* *Blindness (Ophthalmia neonatorum)
4) Pelvic Inflammatory Disease (PID):
- -Salpingitis
- -Pelvic Peritonitis
- -Abscesses
- -Scarring Fallopian tubes+ *Infertility
5) Disseminated Gonococcal Infection (DGI):
- -Skin Rash
- -Arthralgia
- -*Arthritis (purulent, large joints)
Epidemiology:
- -Sexual Transmission
- -50% Women Asymptomatic
Diagnosis: --**Direct Gram Stain (95% positive) Specific in symptomatic men. Other bacteria in female genital flora have similar morphology. --Culture Urethra (men), Cervix (women): **Chocolate Agar + Oxidase Testing --**DNA Amplification Sensitive. Widely used.
Treatment:
- -**Ceftriaxone + **Doxycycline
- -or **Azithromycin
Morphology: --**Gram Negative Coffee bean-shape Diplococci --Motile
Pathogenesis:
- -Opa proteins and Pili mediate Attachment
- -Anti-phagocytic by up-regulation of catalase production after being phagocytosed.
- -LPS and Peptidoglycan shedding cause local injury.
- -Antigenic Variation
Haemophilus ducreyi
Manifestations: --**Chancroid: Painful genital ulcer (tender papule first) --Satellite lesions may be develop --Regional Lymphadenitis
Diagnosis:
–Specific is *Difficult by culture
Treatment:
- -Azithromycin
- -Erythromycin
- -Ceftriaxone
- -Ciprofloxacin
Morphology:
–Gram Negative Rods
