In this video we'll be talking about Neisseria gonorrhoeae. This is a high-yield video for USMLE step 1 and in this video we'll be talking about the salient features of Neisseria gonorrhoeae. This is a particular bacteria that belongs to a group of medically important gram-negative cocci. They form coffee bean-like structures known as diplococci and they are non-spore-forming, catalase-positive and oxidase-positive. Very importantly they are known in context of gonorrhea.
sexually transmitted disease. This is the causative organism. Now in this video we'll be talking about the features of N-gonorrhea, then the pathology and the immunology associated with N-gonorrhea infection, then diagnosis and treatment of gonorrhea. Features of N-gonorrhea.
Neisseria gonorrhea are gram-negative organism. They have thin cell wall that is why their cell wall cannot retain crystal violet and they counter stain with pinkish saffronene and this is how they look like in a microscopic slide here you can see some neutrophils which are heavily infested with this particular N-gonary you can see these dots they are the N-gonary. So N-gonary is fastidious and gram-negative they are facultatively intracellular they cannot live outside the cell they grow and multiply inside the cell Typically they appear in pairs so they are generally diplococci. Also they are capable of moving very fast with twitching kind of mobility.
They are obligate aerob that means they require oxygen in order for them to grow. So question is where does Nisseria gonorrhoea belong in the microbial world? If we classify the free-living bacteria with the help of gram staining classification then they are gram negative bacteria, they are gram negative cocci.
and under that we can find two important species of Neisseria, the Neisseria gonorrhoeae and Neisseria meningitis. The first one is responsible for the sexually transmitted disease gonorrhoea and the second one is important for meningitis infection. Now we'll be focusing on Neisseria gonorrhoeae, but how it is transmitted? It can be transmitted via unprotected sex, multiple partner, during pregnancy or even during blood transfusion.
Incidence of Neisseria gonorrhea infection is increasing day by day throughout the world which is pretty much concerning. When it comes to symptoms of gonorrhea there could be abdominal pain, discharge from penis and vagina, there could be painful urination etc. Now Neisseria gonorrhea can dock onto epithelial cells with the help of their pili and OMP2 protein and this facilitates the bacteria to dock into several epithelia like urethra, cervix, rectum or even conjunctivitis and it can modulate the immune system.
Let's see how immune escape happens in case of N gonorrhea. So N gonorrhea has pili which protects them from being phagocytes by macrophages or dendritic cells. They can also secrete a protein known as N gonorrhea. IgA protease that can cleave the IgA antibody and save them from the humoral immune response.
They can block the complement system, they can suppress the Th1 and Th2 subpopulation of T cells and they can induce the Th17 subpopulation of T cells which triggers inflammation and neutrophil mobilization. Neutrophils are themselves infested heavily by N-gonary and they can be used to control the immune response. and it ultimately lead to burst of the neutrophil and death of these neutrophil which alleviates the overall infection. N gonorrhea has several modification in their surface adhesion proteins which can prevent the alternative and the classical complement pathway and that is how one of the innate defense system is kind of disarmed for the cells.
Now it can modify the activity of different phagocytotic cells for example. The macrophage can basically uptake these N-gonorrhea, but the phagosome fail to destroy the N-gonorrhea. Same for neutrophil.
Neutrophils are also phagocytotic. They can uptake these bacteria, but they cannot destroy them. Generally, neutrophil and macrophage undergo a process known as oxidative burst. In this case, they destroy these pathogens with the help of reactive oxygen species.
Now, N-gonorrhea has developed mechanism by which they can counter the reactive oxygen species and protect themselves. Also it can be detected by specific TLRs and instead of secreting pro-inflammatory cytokines and sometimes they also secrete cytokines which are anti-inflammatory and they prevent the dendritic cells activity and they prevent or they suppress the dendritic cells such that they cannot activate other T cells. So N-gonorrhea has plethora of ways by which it can evade the immune response, which is pretty fascinating.
At the same time, it is pretty dangerous. Let's talk about the diagnosis of N-gonorrhea. So in this area, gonorrhea could be isolated using Thiermarten media. It is a modified chocolate agar media, which has an antibiotic cocktail.
So it has vancomycin, niacin, and colistin. Now more accurate diagnosis can be made via PCR based test from the urine. So basically it is more sensitive, quick and the problem is it is costly, cannot be used in every health setup but it is very accurate. Also there are ways by which one can understand N-gonorrhea infection. Let's say there are purulent discharge from the vagina or penis and they can put a smear of it and...
gram stain it so gram positive gram negative diplococcus should be visible in the slide but sometimes it could be misleading as well so always pcr based methods or eliza based methods are much more sensitive in terms of detecting the infection now let's talk about the treatment of gonorrhea so who prescribes safe triaxon injection for this kind of treatment you and it's an intramuscular cephalosporin antibiotic so these are bacteria obviously they would be treated with antibiotic cdc recommends a dose of 500 mg intramuscular injection for this particular drug and it will stop the infection but it would not repair what has damaged right so anything which was damaged due to this infection it would be still there but no new damages won't happen Because the bacteria would be dead. So overall the rapid diagnosis of this particular disease is important and Quick treatment would ensure better recovery Anyway, there could be reinfection. So a follow-up after three four months would be highly advisable The concerning factor about Neisseria gonorrhea or overall gonorrhea is it shows highly variable antibiotic response and the There are specific reports which shows that the overall response towards antibiotic differs within ethnicity and geographical area and Neisseria gonorrhoeae is actually gaining antibiotic resistance Which is very difficult before the clinicians because in future it would be very hard to treat with Anyway, scientists are trying to understand what is the basis of these antibiotic resistance and how to overcome this problem but I hope this was well informative and good enough for USMLE. In summary we looked at the common sexually transmitted disease gonorrhea which is caused by N gonorrhea.
We looked at the overall symptoms pain etcetera for in context of gonorrhea. So, gonorrhea can occur in both men and male and females we looked at how it is treated we looked at what are the diagnosis options etcetera. so get more notes and flashcards in my facebook page or my instagram page all the links are provided in the description you can support our channel using super thanks and see you in next video