(Section C: Bacteriology) Lecture 23 Flashcards
Obligate human pathogens
Must be incontact with host to:
* Survive
* Replicate
For bacterial STDs, what is required for transmission?
Human-human contact
Treponema pallidum
* Disease
* Gram stain
* Shape
- Syphilis
- Gram negative
- Spriochetes
Is Treponema pallidum culturable?
Not on normal agar
* Requires host-like conditions to culture
What does Treponema pallidum not tolerate?
- Desiccation (dryness)
- High temperature
- Atmospheric oxygen level
How is Treponema pallidum transmitted?
- Sexual transmission
- Mother/child transmission
What are the 3 stages of syphilus?
- 3-90 days after exposure: Genital, tongue sores
- 4-10 weeks after exposure: Body rash (not itchy)
- 3-15 years after exposure: Affects internal organs
What is the prevalence of syphilus (T. pallidum)?
(2020 data)
25 cases/100,000
Treponema pallidum
* Infective ability
As few as 10 cells needed to transmit disease
Does T. pallidum have LPS?
No
What is the function of internal flagella of T. pallidum?
The help move (in a spiral-like shape)
How does T. pallidum evade immune response?
Antigenic variations of TrpK
* Many variations, causing insufficient immune response
What are the functions of outer membrane proteins in T. pallidum?
Attachment to epithelial cells and extracellular matrix
What are the 3 virulence factors of T. pallidum?
- No LPS, has internal flagella
- Antigenic variation of TrpK
- Outer membrane proteins
Treponema pallidum
* Diagnosis
* Vaccine
* Treatment
- PCR and Serologic tests
- No vaccine available
- Antibiotics treatment (penicillin or doxycycline/ceftriaxone)
Neisseria gonorrhoeae
* Disease
* Gram stain
* Shape
- Gonorrhea
- Gram negative
- Diplococci
Neisseria gonorrhoeae
* Mobility
* Type of pathogen
* Transmission
- Non motile
- Obligate human pathogen
- Sexual transmission and Mother/child
Can Neisseria gonorrhoeae undergo non-physiological changes?
No
Neisseria gonorrhoeae
* Signs/symptoms (female)
* Signs/symptoms (male)
(Don’t memorize all)
Female
* Abdominal pain
* Increased vaginal discharge
* Painful urination
* Painful intercourse
* Vaginal bleeding between periods
Male
* Discharge from the penis
* Swollen testicles
* Painful urination
* Urinary tract infection (UTI)
* Inflammation fo the penile
Prevalence of gonorrhea
(2020 statistics)
81 cases/100,000
What is a condition of the eye caused by N. gonorrhoeae?
Gonococcal conjunctivitis
What is the basic life cycle of N. gonorrhoeae?
- Attachedment to epithelium
- Microcolony formation
- Release of peptidoglycan, LOSA, and OMVs
- Invasion, intake by macrophage (cytokine, chemokine and inflammatory transcription factor activation)
- Activates macrophages and neutrophils
- Influx of neutrophils phagocytosis of N. gonorrhoeae
- Neutrophils transmit disease
What are virulence factors in N. gonorrhoeae?
- Type IV pili
- Opa (opacity protein)
- Cell wall antigen (LOS)
- PorB (OM porin)
Explain virulence factors:
Type IV Pili
Highly antigenic, meaning difficult for immune system to respond to variants
Explain virulence factors:
Opa (Opacity protein)
Prevents opsonization, highly antigenic also
Explain virulence factors:
Cell wall antigen (LOS)
Causes disease
Explain virulence factors:
PorB (OM porin)
Punches pores in membrane to causes disease
Neisseria gonorrhoeae
* Diagnosis
* Vaccine
* Treatment
- PCR and Culture
- No vaccine available
- Last resort antibiotic (cephalosporin), urgent need for new therapeutics
How does N. gonorrhoeae gain antibiotics resistance?
Mtr efflux pump
* Pumps antibiotics out of the cell
Chlamydia trachomatis
* Disease
* Gram stain
- Chlamydia
- Gram negative
What is the peptidoglycan structure of C. trachomatis?
Thin or no peptidoglycan layer
Chlamydia trachomatis
* Type of pathogen
* Transmission
- Obligatory intracellular pathogen
- Sexual or Mother/Child
What percentage of males and females are asymptomatic in Chlamydia?
Female: 80-90%
Male: Up to 90%
Chlamydia trachomatis
* Signs/symptoms (female)
* Signs/symptoms (male)
Female
* Cervicitis
* Prolonged menses
* Spotting and vaginal discharge
* Tubing infertility or extopic pregnancy
Male
* Urethritis evolving to epididymitis
* Dysuria and penile discharge
Prevalence of Chlamydia
(2020 statistics)
279 cases/100,000
Chlamydia trachomatis
* Life cycle
Stage 1
* Elementary body attaches and enters
* Differentiates to reticulate body and forms endospore
Stage 2
* Reticulate body fusion and inclusion growth
* Splits into persistent form and activated form
* RB to EB differentiation
* Exocytosis and release of EBs
Chlamydia trachomatis
* Virulence factors
- LPS
- Major outer membrane protein (MOMP)
- Secretion system (T3SS, T2SS, T5SS)
In C. trachomatis:
What is LPS presumably binding to?
CFTR
* Cystic fibrosis receptor
What are MOMPs?
Polysaccharide receptors (for mannose)
What secretion is unique to Gram negative bacteria?
T3
(E.x. T3SS)
Chlamydia trachomatis
* Diagnosis
* Vaccine
* Treatment
- PCR and Culture
- No vaccine available
- Antibiotics (azithromycin or doxycycline)
Syphilis
* Time span of disease
Long time of growth/development of disease
In gonorrhea, which sex is more likely to show symptoms?
Males
What is the most common STI?
Chlamydia
What is the association between STIs and HIV?
HIV patients have higher risks getting STIs
* Especially syphilis and gonorrhea
Why is there association between STIs and HIV?
Both are sexually transmitted pathogens
How do we prevent STIs?
Avoid behaviors that put you at risk:
* Not using condoms
* Multiple partners
* Anonymous partners
* Consumption of drugs and/or alcohol
Get tested when sexually active
STD
Sexually Transmitted Disease
* Refers to a recognizable disease state that has developed from an infection
STI
Sexually Transmitted Infection (STI)
* Refers to a pathogen that causes infection through sexual contact
