Gram Negative Bacteria: Neisseria gonorrhoeae — Transcript

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1. 0:01Assalam alaikum everyone and  welcome to a new ATP video
2. 0:06Today we will be talking about the gram-negative  bacteria that have diplococcus arrangement.
3. 0:11Probably the only pathogenic bacteria  that have this arrangement is Neisseria.
4. 0:16Neisseria has 2 main important species:  Neisseria meningitides and Neisseria Gonorrhea.
5. 0:23In this video we will talk  about Neisseria Gonorrhea.
6. 0:27But first, let’s start with the shared  features between the 2 species
7. 0:31First of all, both gram negative diplococci second of all they are both oxidase positive
8. 0:40For the lab stuff, Neisseria  species grow on chocolate agar
9. 0:44Now let’s talk about culturing Neisseria: But what is that? Do we actually use chocolate?
10. 0:48No, not really
11. 0:50Neisseria species can’t grow on blood  agar because it is inhibited by some
12. 0:55of the elements in the blood agar,  however, when we heat the blood agar,
13. 0:59these inhibitory elements become  inactive and thus Neisseria can grow.
14. 1:03This heated blood agar is in  fact the famous Chocolate Agar
15. 1:07The other agar that Neisseria  grows on is Thayer-Martin agar
16. 1:12which is a selective agar that only  allows Neisseria species to grow
17. 1:16while inhibiting other organisms from growing.
18. 1:19This is also known as VCN agar,  referring to the antibiotics
19. 1:23used to inhibit the other organisms which  are: vancomycin, colistin, and nystatin.
20. 1:29Now let’s move to the shared virulence factors:
21. 1:32• Pilli which allows attachment to  mucosal surfaces. These pili also
22. 1:38display antigenic variation (which makes it  difficult for our immune system to target)
23. 1:42• IgA protease will cleave IgA  antibodies at its hinge point,
24. 1:52this facilitates Neisseria survival  along mucosal surfaces (because
25. 1:57remember that IgA antibodies are found  predominantly at the mucosal surfaces)
26. 2:02• Since N. meningitides is a gram –ve bacteria,  he has the ability of producing endotoxin, but
27. 2:09be aware that Neisseria endotoxin is a little bit  different than the original one that you already
28. 2:14know about. It has a Lipooligosaccharide instead  of Lipopolysaccharide. You can think of it as an
29. 2:23alternative version of the Lipopolysaccharide  found in other gram –ve bacteria.
30. 2:27Lastly, you need to know that patients  with C5-C9 deficiency (also known as
31. 2:34terminal complement deficiency)  are more susceptible to Neisseria
32. 2:38infection because these particular  complement proteins are essential
33. 2:41to form the MAC or membrane attach complex,  that is usually used to cause bacteriolysis
34. 2:48So when these proteins are deficient, this  will make the patients unable to form the
35. 2:50MAC complex and that will lead them  to become more prone to infections.
36. 2:55Now let’s focus on N. gonorrhea
37. 2:59First remember that N. Gonorrhea does  not ferment maltose and does not have
38. 3:04polysaccharide capsule like N. meningitides.
39. 3:06Now let's discuss the pathogenesis  of N. gonorrhea infection
40. 3:11N. gonorrhea can affect both men  and women and result in gonorrhea.
41. 3:16Let’s first discuss the gonococcal disease in men: A man can acquire N. Gonorrhea by having
42. 3:21unprotected sexual intercourse with infected  individual. After acquiring the infection,
43. 3:26N. gonorrhea will first damage the  urethra and cause inflammation or
44. 3:30urethritis and they will present with  painful urination along with purulent
45. 3:35discharge. The infection can complicate  and cause prostatitis and epididymitis.
46. 3:40Although some men remain asymptomatic they can
47. 3:44still can pass the infection  to another sexual partner.
48. 3:47Now let’s move on to the ladies:
49. 3:49Like men, women can develop urethritis and present  with painful urination and purulent discharge,
50. 3:55however unlike men, a large percentage  of women will remain asymptomatic.
51. 3:59In addition to urethritis, N. gonorrhea can  also affect the cervix and cause inflammation
52. 4:05or cervicitis. Again, a large percentage  of these women will remain asymptomatic,
53. 4:11however some will present with lower  abdominal discomfort, pain with sexual
54. 4:18intercourse (dyspareunia), and  a purulent vaginal discharge.
55. 4:20What is important to remember here is that,  the infection of the cervix can ascend and
56. 4:25cause pelvic inflammatory disease, also  known as PID, which is the inflammation
57. 4:31of uterus, fallopian tube, and/or the  ovaries. PID patient presents with:
58. 4:36• fever • lower abdominal pain
59. 4:38• abnormal menstrual bleeding • and cervical motion tenderness
60. 4:42Cervical motion tenderness is the pain that is  elicited when the cervix is moved by the doctor's
61. 4:48examining finger. Cervical motion tenderness  is a very important clinical sign for PID.
62. 4:53Now it is important to note that  presence of intra uterine device,
63. 4:59which is used for contraception,  increases the risk of progression to PID.
64. 5:04Okay now let's focus on the  possible complications of PID:
65. 5:091- Infertility (and the way this  happens is that you form a scar
66. 5:13tissue in the fallopian tube which  can block it and that will prevent
67. 5:17the egg from meeting the sperm) 2- Scaring and ectopic pregnancy
68. 5:23Do you need where is the most common  site for ecotpic pregnancy to happen?
69. 5:27Take a moment A: The ampulla of the fallopian tube
70. 5:313- Peritonitis, this is when the infection spread  from the follapian tube into the peritoneal fluid
71. 5:374- Fitz-Hugh-Curtis syndrome, in which  the Infection spreads to the liver
72. 5:43capsule resulting in formation of adhesions  between the liver capsule and the peritoneum
73. 5:48and these adhesions are called  “Violin String” adhesions.
74. 5:52Also, in men and women, N. gonorrhea can cause  septic arthritis, this happen when N. gonorrhea
75. 5:59spread into the blood and causes inflammation  of the joints. Typically, septic arthritis
76. 6:03caused by N. gonorrhea affects more than one  joint which is why it's called polyarthritis,
77. 6:09and in addition to that, the condition is  associated with skin lesions and tenosynovitis
78. 6:15(or inflammation of the muscle tendon) Now for the last clinically relevant
79. 6:20information about N. gonorrhea, you should  know that it can affect neonates as well
80. 6:24The infection is transmitted form infected  pregnant woman to her baby during delivery,
81. 6:29through the birth canal, which would  then affect the eyes and result in
82. 6:33inflammation of the conjunctiva, also  known as purulent conjunctivitis. The
83. 6:39symptoms start to appear within 5 days  after delivery. In contrast purulent,
84. 6:44conjunctivitis caused by chlamydia  is usually delayed beyond that.
85. 6:47Now for the treatment, we usually  use ceftriaxone + azithromycin
86. 6:52Ceftriaxone is a 3rd generation cephalosporin and azithryomycin is a macrolide
87. 6:57For prevention, we sadly don't have a vaccine for
88. 7:01this species yet Do you know why?
89. 7:03It is because of the antigenic  variation that the pili display
90. 7:07And that is all what you need  to know about N. gonorrhea.
91. 7:10Please give us your feedback so  we improve in the next videos.
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93. 7:18And as always, thanks for watching!