3rd Lecture: Gonorrhea and Chlamydia Flashcards
1
Q
What are the 6 learning objectives of this lecture?
A
- Describe gonococcus and Chlamydia transmission and disease
- Compare/contrast LPS and LOS
- Discuss appropriate agar media for Neisseria in vitro.
- Differentiate intracellular from extracellular bacterial infection.
- Describe Chlamydia’s unique life cycle (elementary & reticulate).
- Cite the common effective measures for treatment and prevention of both these STIs.
2
Q
What are the 8 characteristics of N. gonorrhoeae (gonococcus)?
A
- Gram negative diplococci
- Human-restricted
- Oxidase positive
- Won’t grow on blood agar, use chocolate agar or Thayer-Martin as appropriate
- NOT encapsulated
- Hundreds of serotypes
- Very sensitive to dehydration, cold
- Plasmid-borne Ab resistance more common than in meningococcus, cephalosporin resistance emerging right now
3
Q
What are the 2 modes of transmission of
N. gonorrhoeae?
A
It can be transmitted either sexually or via birth
4
Q
What are the three ways that N. gonorrhoeae use to accomplish it’s pathogenesis?
A
- Pili
- IgA protease
- Opa virulence factors
5
Q
(Kaplan) What are the roles of Pili?
A
- Attachment to mucosal surface
- Inhibit phagocytic uptake
- Antigenic (immunogenic) variation: over 1 million variant
6
Q
(K) What is the role of IgA protease?
A
Aids in colonization and cellular uptake
7
Q
(K) What is the role of Opa proteins?
A
Antigenic variation, adherence
8
Q
What is the role of porin A and B?
A
Confer serum resistance in strains that are more likely to disseminate (Disseminated Gonococcal Infection)
9
Q
In case of male, is N. gonorrhoeae usually symptomatic?
A
Yes, anterior urethritis
10
Q
In case of female, is N. gonorrhoeae usually symptomatic?
A
No, it’s often asymptomatic (However, it can cause cervicitis, Type IV pili confer “twitching motlity” –> progression to PID)
11
Q
In case of neonate, what does N. gonorrhoeae cause?
A
Purulent conjunctivitis
12
Q
True or False
Unlike syphilis, the symptoms develop quickly (no latency)
A
True
13
Q
During the exam, what can be observed from a male pt who has N. gonorrhoeae?
A
- Urethritis
- Dysuria
- Purulent discharge
14
Q
During the exam, what can be observed from a female pt who has N. gonorrhoeae?
A
- Purulent vaginal discharge
2. PID: pain, bleeding, perihepatitis, thick Fallopian tubes or abscess on sonogram
15
Q
What symptoms are seen from both sex?
A
Coinfection of pharynxy, rectum, eye may occur
16
Q
What can disseminated infection cause?
A
- Lack of urogenital symptoms
- Arthritis/dermatitis
- Septic arthritis
- Rarely meningitis, endocarditis
17
Q
What can N. gonorrhoeae cause in neonate?
A
bilateral conjunctivitis, if untreated permanent blindness
18
Q
What are the labs you need to do for male pt?
A
- First, test urine and exudate for PMNs and intracellular diplococci
- If needed, obtain urethral swab for Gram stain, culture on Thayer-Martin agar
19
Q
What are the labs you need to do for female pt?
A
Obtain endocervical smear, culture on Thayer-Marin
20
Q
What are the labs you need to do for disseminated gonococcal infection?
A
- Gram-stain, culture sample from all affected areas
2. Blood, joint fluid may be cultured on nonselective chocolate agar
21
Q
When should the treatment for gonococcal infection begin?
A
Begin antibiotics before labs come back
22
Q
What are the drugs needed to treat gonococcal infection?
A
- Ceftriazone, alternate cefixime, cephalosporin
23
Q
When treating gonococcal infection what other drugs do you need to add?
A
Add azithromycin or doxycycline for coinfection with Chlamydia
24
Q
What is a prevention for neonatal dz due to gonococcal infection?
A
erythromycin ointment on eyes at birth
25
What is unique about C. trachomatis?
It has unique life cycle:
1. dense, rugged elementary bodies (EBs) attach to cell, endocytosed, survive, "upack" into reticulate bodies
2. larger, delicare, RBs replicat, metabolise, pack into EBs, escape host cell
26
What form of C. trachomatis is only infectious?
elementary bodies (reticulate bodies only divide)
27
How are symptoms of genital Chlamydia trachomatis determined?
by serovar (serotype)
28
What are the serotypes of C. trachomatis that causes blind?
A, B, Ba, C
29
serotypes A, B, Ba, C of C. trachomatis cause
1. a leading preventable blindness
2. spread by secretions, fomites
c. endemic to Africa, southern Asia
30
What serotypes cause lymphogranuloma venereum?
1. L1-L3
31
What are some characteristics of lymphogranuloma venereum?
1. small ulcer proceeds to painfully swollen lymph node near genitals
2. sexually transmitted
3. endemic to South and Central America
32
What serotypes cause genital chlamydia?
D - K
33
What are some important characteristics of genital chlamydia?
1. The most common STD in US
2. Often asymptomatic
3. May spread sexually or infect newborns at birth
34
How do you diagnose blinding trachoma?
eyelashes turned inward, travel to endemic area
35
During the exam of trachoma what do you find from a female pt.
mucopurulent endocervical discharge, bleeding, dysuria, abdominal pain, progression to pelvie inflammatory dz (PID)
36
During the exam of trachoma what do you find from a male pt.
Urethral discharge, dysuria, scrotal pain
37
Both female and male pts with trachoma have high risk for
Reiter syndrome = reactive arthritis
38
infants with trachoma are risk for
1. ocular trachoma
| 2. pneumonia
39
What is the lab to diagnose infant ocular trachoma?
stain eye swab with Giemsa or IF for chlamydial inclusions
40
C. trachomatis can be cultured?
yes
1. C. trachomatis grows well in many common cell lines
2. Culture required if case has legal implicaitons
41
What are the molecular methods to diagnose C. trachomatis?
1. fluorescent hybridiation, ELISA, PCR
| 2. more likely to give a false positive
42
What is required to treat C. trachomatis?
Antibiotics, must be able to penetrate infected cell membranes
43
What are the antibiotics to treat C. trachomatis?
Doxycycline or azithromycin
44
For peds, pregnant, and pts who are allergic to doxycylcline or azithromycin, what antibiotics are used?
Erythromycin + amoxicillin
45
Is reinfection of C. trachomatis common?
yes
46
What risk needs to be counseld with C. trachomatis infection?
Reactive Arthritis as sequel
47
(FA) Dicuss Neisseria gonococci and meningococci
1. gram - diplococci
| 2. both ferment glucose and produce IgA proteases
48
(FA) What is characteristics of Neisseria gonococci?
1. No polysaccharide capsule
2. No maltose fermentation
3. No vaccine (due to rapid antigenic variation of pilus protein)
49
(FA) What does neisseria gonococci cause?
1. gonorrhea
2. septic arthritis
3. neonatal conjunctivitis
4. PID
5. Fitz-Hugh-Curtis syndrome
50
(FA) what is the treatment for Neisseria gonococci?
ceftriaxone
51
(FA) what is ceftriaxone?
3rd generation cephalosporins
52
(FA) What is a characteristics of Chlamydiae?
1. Chlamydiae cannot make their own ATP
| 2. they are obligate intracellular organisms that cause mucosal infection
53
What are the 2 forms of chlamydiae?
1. Elementary body (small, dense)
| 2. Reticulate body
54
Elementary body of chlamydiae is
Enfectious and Enters cell via endocytosis
55
Reticulate body
Replicates by fission; form seen on tissue culture
56
(Goljan) a little kid was born and a week later he was wheezing (big time), pneumonia, increased AP diameter, tympanic percussion sounds, no fever, eyes are crusty (both sides), weird cough - staccato cough (short coughs)
What is the diagnosis?
Chlamydia trachoomatis
57
(Goljan) What is the most common conjunctivitis in 2nd week newborn?
Chlamydia trachomatis
58
(Goljan) How does a baby get Chlamydia trachomatis?
through mom's infected cervix
59
(G) Does normal urine culture pick up Chlamydia?
No
60
(G) Pt with dysuria, increased frequency, neutrophils in the urine, few RBC's, no bacteria, + leukocyte esterase (indicates UTI), urine culture is negative, and sexually active person. What is the diagnosis?
Chlamydia – normal urine cultures do not pick up Chlamydia trachomatis
61
N. gonorrhoeae like N. meningitidis
1. diplococci
2. human restricted
3. oxidase positive
4. growth in vitro inhibited by trace metals and fatty acids: chocolate agar not blood agar
5. complement def is predisposing factor for infection
6. has LOS (lipooligosaccharide) lower molecular weight than LPS
62
N. gonorrhoeae unlike N. meningitidis
1. not encapsulated
2. hundreds of serotype
3. even more sensitive to dehydration, cold
4. plamid borne antibiotic resistance more common (cephalosporin resistance)
63
Pathogenesis of N. gonorrhoeae
1. transmitted sexually or at birth
2. neonate: pururlent conjunctivitis
3. male usually symptomatics
4. female: usually asymptomatic, cervicitis
64
Infection in children is
a reportable marker for sexual abuse
65
incidence in US of N. gonorrhoeae?
700 k new infections
66
Virulence factors of N. gonorrhoeae?
1. IgA protease clears IgA from mucosal surfaces to facilitate colonization
2. Pili
3. Opa (opacity assocaited proteins enchances cell adhesion)
4. Porin A and B (channels in outer membrane confer serum resistance, enhance cell entry)
67
What is PID?
spread of cervical infection to fallopian tubes creates pain, risks of infertility and ectopic preg
68
N. gonorrhoeae can lead to dissemination (bacteremia)
1. virulence factor is serum resistance including protein proin A
2. more common in women
69
N. gonorrhoeae can cause
co-infection of pharynx
70
PID
1. lower abdominal pain
| 2. Fitz-Hugh-Curtis syndrome --> acute perihepatitis
71
Disseminated infection (DGI)
1. often lack urogenital symptoms
2. arthritis/dermatitis syndrome with joint pain and skin pustules
3. asymmetric tenosynovitis with pain in wrists and ankles
4. progression to septic asymmetric arthritis (knee common)
72
N. gonorrhoeae rarely lead to
1. Gonococcal meningitis
| 2. Endocarditis (more common in me, heart valve involved)
73
N. gonorrhoeae in neonates
1. bilateral conjunctitivits --> can lead to blindness
| 2. infection may also be pharyngeal, resp, rectal, or disseminated
74
Intracellular N gonorrheae diplococci
is definitive for N. gonorrhoeae diagnsos
75
If negative with a pt who is suspicious of N. gonorrhoeae infection
obtain urethral swab, culture on Thayer Martin (chocolate agar with drugs to inhibit normal flora)
76
Treatment for N. gonorrhoeae?
1. begin promptly, in advance of labwork
2. Ceftriazone (alt cefixime), also give azithromycin for Chlamydia
3. admitted if the pt shows some symptoms of disseminated dz
77
Reticulate bodies
1. non infections
2. metaboliclly active
3. synthesize its own DNA but needs ATP from host
78
Urogenital chlamyida is specifically due to
C. trachomatis
79
Serotypes A, B, Ba and C cause
blinding trachoma
80
Blinding trachoma is spread by
secretions - direct and fomites
81
Lymphogranuloma venereum
1. aspiration of buboes and fistulas may speed healing
| 2. serotype D-K
82
Genital Chlamydia
1. 4 million infections per yr
2. often asymptomatic
3. most commonly local mucosal inflammation and discharge
4. lead to PID (a leading cause of PID and infertility in women)
5. PID creates risk of chronic pain and ectopic preg
83
Reiter syndrome = reactive arthritis is secondary to
an immune mediated response (Chlamydia is one of several infections known to trigger it
84
80% of Reiter syndrome = reactive arthritis pt are
human leucocyte antigen-B27 (HLA-B27)–positive.
85
For urogenital chlamydia
co-incident Chlamydia in all STD patients
86
Doxycycline is contraindicated
in pregnant or <9yr old patients
87
Reinfection if urogenital chlamydia is
very common
88
What are the virulence factors for N. gonorrhoeae?
IgA protease, pili, LOS, Porins, Opa
89
N. gonorrhoeae is
gram(-) diplococci, aerobic/facultative, human-restricted, oxidase-positive, catalase-positive
90
N. gonorrhoeae Growth is
inhibited on blood agar and overgrown by normal flora on nonselective media: use Thayer-Martin if normal flora (genital, nasopharyngeal), chocolate if normally-sterile (CSF, blood)
91
How does host defends againts N. gonorrhoeae?
1. IgG-enhanced complement and PMNs (which usually contains gonococcus)
92
Complement deficiency
predisposes to complications.
93
Asymptomatic/Untreated gonococcus in women
leads to PID
94
Other serious complications follow bacteremia (N. gonorrhoeae:
DGI, septic arthritis, meningitis, endocarditis
95
(N. gonorrhoeae) Neonates must be protected
by prophylactic eye ointment
96
What is the treatment for N. gonorrhoeae?
ceftriaxone, cefotaxime
97
Chlamydia is
a small, obligate intracellular bacterium (so must use drugs that penetrate the human cell membrane).
98
Chlamydia replicate
in a unique manner beginning with tiny, infectious, rugged, elementary bodies which “unpack” into reticulate bodies after infection.
99
Reticulate bodies form intracellular inclusions that are visible on microscopy; within the inclusions
they multiply by binary fission, forming new reticulate bodies and later new elementary bodies.
100
Unusual life cycle complicates research; one known virulence factor is
T3SS used for entry & establishing inclusion body.
101
C. trachomatis causes
LV, blinding trachoma, and pneumonia (Unit 4) in addition to urogenital “chlamydia”
102
Treatment can often be initiated
based on physical findings, additional diagnostics are available and may be desired in various situations (tissue culture for C. trachomatis in rape victims).
103
Treat C. trachomatis with tetracyclines (doxycycline) EXCEPT for pregnant/pediatric/allergic patients,
who get erythromycin or other alternatives. Patients who get alternatives may need follow-up testing and retreatment.
104
(FA) What are the 3 diseases caused by Chlamydia trachomatis?
1. Reactive arthritis
2. Conjunctivitis
3. Nongonococcal urethritis
4. PID
105
(FA) Chlamydia pneumoniae and Chlamydia psittaci cause
atypical pneumonia transmitted by aerosol
106
(FA) What is the treatment for Chlamydia infection?
Azithrozycin (favored b/c one time treatment) or doxyclcline
107
(FA) What is notable for Chlamydia psittaci?
notable for an avian reservoir
108
(FA) In what aspect is the chlamydial cell was unusual?
lacks muramic acid
109
What is the lab diagnosis for chlamydia?
1. ctyoplasmic inclusion seen on Giemsa or fluorescent antibody- stained smear
110
(FA) What serotypes of C. trachomatis cause chronic infection, blindness due to follicular conjunctivits in Afirca?
ABC = Africa/Blindness/Chronic infection
111
(FA) What serotypes of C. trachomatis cause urethritis/PID, ectopic pregnancy, neonatal pneumonia (staccato cough), or neonatal conjunctivitis?
D-K (neonatal dz can be acquired during passage through infected birth canal.)
112
(FA) What serotypes of C. trachomatis cause lymphogranuloma venereum?
L1, L2, L3
113
(Goljan) Chlamydia cause in man what?
nonspecific urethritis
114
(Goljan) In woman Chlamydia cause
urethral syndrome
115
(Goljan) What is unique about Chlamydia infecation?
1. Normal urine cultures (do not pick up C. trachomatis)
| 2. We don't have bacteria, but do have neutrophil present
116
What are the two causative agent for sterile pyrusia?
Chlamyida infection and TB
117
20 yr old, dysuria, increased freq, urinalysis= leucocyte esterase positive, sterile pyuria--sexually active, had non-specific
urethritis, conjunctivitis, was treated. It was Chlamydia trachomatis conjunctivitis, but one week later, got sterile conjunctivitis and
tendonitis in Achilles tendon. What is the diagnosis?
Patient with non-infectious conjunctivitis, previously had Chlamydia trachomatis infection and then developed conjunctivitis and arthritis (HLA B27 positive): Reiter's syndrome
118
What is another environmental trigger in HLAB27 positive pt?
Ulcerative Colitis
