medical micro - UT/STI Flashcards
what do lower UTI’s involve
bladder - cystitis
urethra - urethritis
what do upper UTI’s affect
kidneys - pyelonephritis
ureters - ureteritis
difference between symptomatic and asymptomatic infection
symptomatic - display symptoms of disease
asymptomatic - significant number of bacteria but no symptoms
give anatomical reasons why women are more susceptible to UTI
shorter urethra
closer to the bladder
how does birth control contribute to female UTI
spermicidal agents and diaphragms in the birth control can increase risk of infection
how does menopause increase risk of UTI
decline in circulating oestrogen, causes changes to urinary tract, more vulnerable to infection.
different between single or reccurant UTI
single - only happens ones
reccurant - relapse with same/ different organism
difference between un/complicated UTI
uncomplicated - no additional UT problems
complicated - other factors associated with the infection
outline how a lower UTI can progress to an upper UTI
1 - colonisation
2 - uroepithelium penetration
3 - ascension
4 - pyelonephritis
5 - acute kidney injury
what do UTI tests generally depend on
chemical tests - dipstick
bacterial culture
difference between polyuria/haematuria and dysuria
polyuria - excessive urine output
haematuria - blood in urine
dysuria - pain when pissing
what is the definition to area above the pubis
suprapubic
what is pyruia
presence of pus/WBC in urine
what do leukocytes in the urine indicate and how to detect it
body is fighting an infection
test detects leukocyte esterase
what is the primary cause of UTI’s
uropathogenic E. coli
what are the virulence factors of uropathogenic E. coli
adhesion - prevents removal in urine flow
survival - acquires iron and evades host defences
toxicity - leads to infalmmation
what are the primary adherance factors of UPEC and common adhesive organelles
adherence factors:
pili
fimbriae
adhesion organelles:
type 1
P
S
FIC pili
features of type 1
required for colonisation, invasion and persistence
occurs mainly in the bladder
possess FimH - adhesin
what does FimH target
Mannosylated uroplakins
Α1β3 integrins
what happens after UPEC attaches
invasion into umbrella cells
what happens once E. coli invades umbrella cells
activation of Rho GTPase
causes actin rearrangement and internalisation
E. coli gets engulfed by the cell
where is the P pili more active
upper UTI infections
once UPEC is engulfed, what does the host cell membrane cause
leads to exocytosis of UPEC inside of a vesicle into the plasma membrane
this leads to transient biofilm-like intracellular UPEC communities in the host membrane
vesicular UPEC also form quiescent intracellular reservoirs (QIR), what is that
in membrane bound compartments of 4-10 bacteria covered in F-actin
long term viability
what does PapG on P pili bind
globosides present on kidneys
TLR4 to reduce their expression - modulating the immune system
what antibody is effected by PapG binding to globosides
IgA through cells to the kidney lumen
what are other virulence factors of UPEC
siderophores
α-haemolysin (HylA)
cytotoxic necrotising factor 1 (CNF1)
why would siderophores be a useful virulence factor for lower UTI infections
the bladder is an iron-limited environment
function of α-haemolysin (HylA)
causes pore formation in umbrella cells
promotes lysis and release of nutrients and iron
trigger exfoliation - highly expressed in IBC’s
function of CNF1
affects actin modelling
causes membrane ruffling - aids in internalisation
when does initial attachment of proteus occur
after urease causes pH to increase
if proteus is in contact with host tissue, what toxins does it release
α-haemolysin
proteus toxin
function of proteus toxin
punctures host cell membrane
causes cytosol to leak - causing osmotic stress
causes actin depolymerisation
features of lactobicilli
adhere to vaginal cells - prevents colonisation
produce hydrogen peroxide to inhibit pathogenic growth
produces lactic acid to maintain low pH
releases bacteriocins - antimicrobials
can deactivate HIV-1
what does sperm contain for antimicrobial purposes
lysozyme
lactoferrin
phospholipase A2
secretory leukocyte inhibitor
semenogelin 1 derived peptides
what does uncomplicated gonorrhoeae affect
mucus membrane of:
urethra
endocervix
rectum
pharynx
conjuctiva
what can disseminated gonorrhoeae present as
septic arthritis
dermatitis
what are the complications associated with gonorrhoeae in men
acute epididymitis
penile lymphangitis
per-urethral abscess
acute prostatitis
seminal vesiculitis
what are the complications associated with gonorrhoeae in women
Bartholin’s abscess
spontaneous abortion
premature labour
rupture of fetal membrane
what are NAATS used to detect
gonorrhoeae and chlamydia
features of Neisseria gonorrhoeae
gram-negative diplococci
fastidious
facultative intracellular
what are the virulence factors of gonorrhoeae
capsule to resist phagocytosis
Opa proteins to aid in attachment
Pilus protein to attach to epithelium
LOS - liposaccharide with endotoxic activity
release IgA protease
Rmp proteins - inhibits cidal action of semen
Por - created pores in membrane
what is the difference in wo/men in contraction of chlamydia
men - infects urethra
women - infects urethra and/or endocervix
what is the difference between un/complicated chlamydia
uncomplicated - doesn’t ascend to upper genital tract
complicated - ascends to upper genital tract
what does complicated chlamydia cause in wo/men
men - epididymo-orchitis
women - pelvic inflammatory disease (PID)
what does epididymo-orhitis cause
pain/swelling/inflammation in the epididymous/testicles
what is adult conjuctivitis caused by
autoinoculation
what is LGV caused by
infection of lymphatic system
what does SARA cause
polyarthritis of weight-bearing joints
what are the virulence factors of chlamydia
binds to sialic acid on mucus membrane to give it access to immuno-privileged areas
LPS is cysteine-rich to prevent phagocytosis
Type III secretion system
antigenic variation
infested vacuole to divert lipids to itself
what is syphilis caused by
spirochete bacterium - Treponema palladium
how is syphilis transmitted
direct contact with the infectious lesions
what is primary syphilis
painless ulcer
affects genitals
localised lymphadenopathy
what is secondary syphilis
multisystem and one or many regions
what is the progression of syphilis
early latent
late syphilis
late latent stage
tertiary
what is tertiary syphilis divided into
neruosyphilis
gummatous syphilis
features of Treponema palladium
obligate intracellular parasite
fastidious - gram-negative
cork-screw shaped
how does T. palladium reproduce
transverse fission
what is the outer sheath of T. palladium composed of
glycosaminoglycan
what is the function of the axial filament (endoflagella) of T. palladium
provides osmotic stability
covers the protoplasmic cylinder
what are the virulence factors of T. pallidium
adherence proteins
hyaluronidase - allows perivascular infiltration
coats host cells with fibronectin to prevent phagocytosis
