Neisseria gonorrhoeae Flashcards
transmission route of neissaeria gonorrhoeae
sexual contant via secretions of the genital tract
structural advantages of Neisseria gonorrhoeae
type IV pili - attachment to epithelial cells
polysaccharide capsules - preventing the recognition and phagocytosis by macrophages and neutrophils
+ facilitating colonisation on surfaces
lipooligosaccharide (LOS) (Lipid A + oligosaccharide chain) – stimulates the release of pro-inflammatory cytokines
+ structural variations evade recognition from immune cells
type IV pili
attachment to epithelial cells
polysaccharide capsules
protective barrier against the host immune system, preventing the recognition and phagocytosis by macrophages and neutrophils
+ facilitating colonization on surfaces
lipooligosaccharide (LOS)
(Lipid A + oligosaccharide chain) – activator of the host immune response – stimulates the release of pro-inflammatory cytokines
+ structural variations evade recognition from immune cells
Lipid A is an endotoxin that exacerbates tissue damage by stimulating pro-inflam cytokines
+ adhesion to host cell
Lipid A endotoxin -
potent stimulator of the immune system and inflammatory response
triggers release of pro-inflam cytokines such as IL-1, IL-6 and TNFa
chronic inflammation can proliferate the infection, exacerbating tissue damage
may lead to fever, septic shock, and organ failure
what Proteases and Enzymes does N. gonorrhoeae produce?
IgA1 Protease
endonuclease NucA
Endonucleases
superoxide dismutase (SOD) and catalase.
Beta-lactamases
IgA1 Protease
cleaves IgA1 antibodies found in mucosal secretions
evades immune response at mucosal surfaces of the genital tract
endonuclease NucA
encoded by the nucA
cleaves both strands in DNA
allowing it to degrade NETs
NETs = web-like structures composed of DNA, histones, and antimicrobial proteins released by neutrophils to trap and kill pathogens
what are the infection rates of gonorrhoea between men and women if had contact with infected individual
men 20%
women 50%
what is the difference in symptoms between men and women?
women - often asymptomatic
may develop Pelvic inflammatory disease (leads to scarring, ectopic pregnancy, infertility)
men - Acute inflammation
- Dysuria (painful urination)
- Purulent (pus-filed) discharge from urethra/rectum
- Pharyngeal infection
- Ascending infection
describe the ability of N. gonorrhoea to Immunomodulate the macrophage
after a macrophage endulfs the bacteria cell, it can:
&Escapes the phagosome&
– creates a membrane rupture by releasing degadation enzymes from the Type IV Secretion System (T4SS) on the membrane surface
– avoiding lysosomal degradation
&Inhibits apoptosis/autophagy&
&Modulates production of cytokines&
– such as interleukin-12 (IL-12) and tumor necrosis factor-alpha (TNF-alpha)
&Modulates iron production from the macrophages&
&Reduces capability of T cell proliferation&
describe the damaged caused by N. gonorrhoea
Infects mucus-secreting epithelial cells in men and women
Disrupts epithelial integrity
Loss of ciliated cells
Fallopian tube scarring
Occlusion of the oviduct
Adhesions = chronic pelvic pain
Urethritis
Systemic dissemination
what are the complications of neonatal gonorrhoea?
severe cornea or conjunctiva infections leading to potential blindness
respiratory infections such as pneumonia and sepsis.
describe antibiotic resistance in Neisseria gonorrhoeae ——-
innate resistance factors from being gram Neg
What is the Gonococcal resistance to antimicrobial surveillance programme (GRASP)?
national sentinel surveillance programme established in 2000 to monitor trends and drifts in susceptibility to antimicrobial agents used for the treatment of gonorrhoea in England and Wales
Explain how GC VCAT (Gonococcal Culture with Vancomycin, Colistin, Anisomycin, and Trimethoprim) is used to diagnose gonorrhea
selective culture medium for Neisseria gonorrhoeae
Base medium - provides nutrients for growth
Vancomyacin - inhibits growth of gram pos by preventing cell wall synthesis
Colistin - is a polypeptide antibiotic that disrupts the integrity of the outer membrane of Gram-negative bacteria, making them more susceptible to other antibiotic
Anisomycin - protein synthesis inhibitor - inhibits the growth of many Gram-positive and Gram-negative bacteria
Trimethoprim - dihydrofolate reductase inhibitor that interferes with folate metabolism in bacteria – suppress growth of contaminating bacteria
Neisseria gonorrhoeae colonies appear small, grey/white, translucent
