Gonorrhea and Chlamydia

Question 1

N honorrhoeae bacteriology

Answer 1

-like n meningitidis:
-diplococci
-human restricted
-oxidase positive
-cleared from bloodstream by immune complement- complement deficiencies are predisposing for complications
-growth in vitro inhibited by trace metals and fatty acids- chocolate agar not blood agar
-gram negative LOS- just a few sugars instead of many (LPS)
unlike n meningitidis:
-not encapsulated
-hundreds of serotypes
-even more sensitive to dehydration, cold
-plasmid borne antibiotic resistance more common
-new and improved cephalosporin resistance

Question 2

n gonorrhoear pathogenesis

Answer 2

• transmitted sexually or at birth
• neonate- purulent conjunctivitis
• male-usually symptomatic- anterior urethritis
• female- often asymptomatic, cervicitis
• genital tract infections most common, anorectal and pharyngeal also occur
• infection in children is reportable marker for sexual abuse

Question 3

gonorrhea pathogenesis 2

Answer 3

• in US- 700 k new infections per year
• most common in african americans, rural southeast, inner cities, young unmarried, low education
• infection rates crashed in 1970s and have been creeping up more recently

Question 4

virulence factors for gonorrhea

Answer 4

-IgA protease clears IgA from mucosal surfaces to facilitate colonization
-pili attach to columnar and transitional epithelium of mucosal surfaces, antiphagocytic
-opa-opacity associated proteins enhance cell adherence and entry
-porin A and B channels in outer membrane confer serum resistance, enhance cell entry
LOS- less immunogenic than LPS, but does induce local IF response (the drip, the clap)

Question 5

gonorrhea pathogenesis 3

Answer 5

• most infections are vaginal or urethra
• antibodies, complement, neutrophils restrict to local site
• PID follows from mixing bacteria with refluxed menstrual blood or attachment to sperm
• can be some twitching mobility by pili
• dissemination can occur
• certain strains more likely to disseminate
• virulence factor is serum resistance, including protein porin A in cell wall (anti complement)
• more common in women
• asymptomatic infection, menses, pregnancy, and complement C6-C9 deficiency also predispose

Question 6

diagnosis of gonorrhea on exam

Answer 6

• extremely contagious- single exposure contraction common
• symptoms develop quickly, within 10 days of infection
  men: urethritis, dysuria, purulent discharge, sometimes unilateral epidiymitis
  women: purulent vaginal discharge, cervicitis, PID, sterility, ectopic pregnancy
  both: coinfection of pharynx, rectum, eye
• all appear irritated/destroyed tissue with discharge

Question 7

PID diagnosis

Answer 7

• lower abd pain
• vaginal discharge
• dysuria
• tenderness
• intermenstrual bleeding
• fitz-hugh-curtis syndrome- bacteria jump from fallopian tube to liver capsule- acute perihepatitis
• sonogram may show thick fallopian tubes or abscess

Question 8

disseminated infection diagnosis

Answer 8

• DGI
• often lack urogenital symptoms
• arthritis, dermatitis syndrome with joint pain and skin pustules
• asymmetric tenosynovitis with pain in wrists and ankles
• moderate fever
• progression to septic asymmetric arthritis (knee common)

Question 9

rare for gonorrhea

Answer 9

• gonococcal meningitis- admit, spinal tap
• endocarditis- echocardiogram, cardio consult
• more common in men
• aortic valve most common site
• subacute onset of fever, chills, sweats, malaise
• chest pain, cough

Question 10

diagnosis in neonates

Answer 10

• bilateral conjunctivitis
• generally infected at birth, can happen postpartum of in utero
• eye pain, redness, discharge
• infection may also be pharyngeal, respiratory, rectal, or disseminated
• untreated, permanent blindness follows quickly

Question 11

lab diagnosis G in males

Answer 11

• try first- urine and exudate testing
• obtain and centrifuge- morning void, swab exudate
• gram stain- PMN indicate urethritis, gram neg intracellular diplococci indicate gonorrhea
• nucleic acid amplification tests are available
• if negative- urethral swab
• gram stain again
• culture on thayer martin-chocolate agar with drugs to inhibit normal flora
• colonies tested for gram neg, oxidase pose, diplococci
• this is required if case has legal implications
• most sensitive and specific (urethral swab)

Question 12

female Lab diagnosis for gonorrhea

Answer 12

• obtain endocervical smear (urethral sample if hysterectomy)
• wipe off exudate first
• culture on thayer martin

Question 13

DGI lab diagnosis

Answer 13

• swab, gram stain, and culture al available mucosal surfaces and fluid draws
• samples from normally sterile sites may be cultured on non-selective chocolate agar (blood, joint fluid)
• immunofluorescence may give better results than gram stain on pustule samples
• *only meningococci ferment maltose

Question 14

gonorrhea treatment

Answer 14

• begin promptly, in advance of lab work if necessary
• check local policy on antimicrobial resistance testing
• ceftriaxone, cefixime
• if allergic to penicillin, cephalosporin, but watch for resistance
• add azithromycin or doxy because chlamydia often co-infects
• aspirate septic joints
• if living in area with known Ab resistance, test cure 1 week after treatment, otherwise follow up in 3 months
• admit if pregnant, PID, DGI, endocarditis, meningitis, purulent joint infection

Question 15

prevention of gonorrhea

Answer 15

• neonatal conjunctivitis-prophylatic application of erythromycin ointment or silver nitrate to eyes shortly after birth
• STD- condoms, prompt treatment of patient and all sexual contacts
• report incidence to local health authority, enlist them if patient resists informing sexual partners
• expedited partner treatment is warranted in some cases

Question 16

chlamydia bacteriology

Answer 16

• doesn’t replicate by lysing or like a virus
• elementary bodies and reticulate bodies
• elementary bodies are tough and small, get into cell, turn into reticulate bodies to replicate, some turn back, the either lyse or reverse endocytosis to get back out

Question 17

elementary bodies

Answer 17

• small- 0.3-0.4 microm
• infectious
• rigid outer membrane
• rugged
• bind to receptors on epithelium of lung or mucous membrane and initiate infection

Question 18

reticulate bodies

Answer 18

• non infectious intracellular form
• metabolically active
• replicating
• synthesizes is own DNA, RNA, and proteins, but requires ATP from host
• fragile gram neg membrane
• inclusions- accumulate 100-500 progeny before release

Question 19

immune response to chlamydia

Answer 19

• inflammatory cascade causes some of the symptoms-swelling, discharge
• IF response usually fails to clear infection or prevent reinfection
• no useful immune memory

Question 20

urogenital chlamydia

Answer 20

• C trachomatis
• 18 serovars- A,B,Ba, C- blinding trachoma
• L1-L3- lymphogranuloma venereum
• D-K- genital tract infections

Question 21

blinding trachoma

Answer 21

• infectious eye disease, leading cause of preventable blindness
• 84 million people suffer, 8 million visually impaired
• spread by secretions- direct and fomites
• untreated eyelids turn inward, causing eyelashes to scratch the cornea
• WHO aims to eradicate by 2020

Question 22

lymphogranuloma venereum

Answer 22

• endemic in south and central america
• rare in US (obtain history of sex while traveling)
• a small, painless ulcer proceeds to swollen, painful lymph nodes
• symptoms are caused by bacterial replication in the mononuclear phagocytes of the local lymph nodes
• labwork and treatment are the same as for other genital chlamydia
• aspiration of buboes and fistulas may speed healing

Question 23

genital chlamydia

Answer 23

• 4 million infections per year
• prevalence rates over 10% in sexually active adolescent females
• often asymptomatic, esp in male reservoirs
• most commonly local mucosal inflammation and discharge, urethritis or urethritis/vaginitis/cervicitis
• infection increases risk of acquiring HIV
• pregnant women infected can pass infection to infants during delivery
• leading cause of PID-chronic pain and ectopic pregnancy

Question 24

risk factors for chlamydia

Answer 24

• non-barrier contraceptive use
• multiple sexual partners
• single marital status
• age <19
• socioeconomic disempowerment

Question 25

reiter syndrom

Answer 25

- reactive arthritis - secondary to immune mediated response - chlamydia is one of several infections known to trigger it - conjunctivitis + urethritis+ arthritis - 80% of affected patients are HLA-B27 positive - treated with NSAIDs, may take 2 years to resolve

Question 26

women chlamydia exam

Answer 26

- easily induced endocervical bleeding - mucopurulent endocervical discharge - intermenstrual bleeding - dysuria - abd pain

Question 27

men chlamydia exam

Answer 27

- urethral discharge - urinary frequency and/or urgency - dysuria - scrotal pain/tenderness - perineal fullness

Question 28

lab chlamydia

Answer 28

- test for coincident chlamydia in all STD patients - physical findings often sufficient - cytologic- infant ocular trachoma- cell sample stained with giemsa or IF - isolation in cell culture- grows well in a variety of cell lines- always do the culture if case has legal implications - detection of chlamydia rRNA by hybridization with a DNA probe and other nucleic acid amplification methods- simpler and less expensive, but more likely to give a false positive - ELISA or PCR from urine or exudate - serology not useful- past infection too likely

Question 29

chlamydia treatmetn

Answer 29

- intracellular - doxy or azithromycin - no doxy in pregnant or less than 9 years old - second choice- erythromycin and amoxicillin- test the cure - infection hidden behind gonococcal- test for full STD panel - reinfection very common - test partners/ treat simultaneously - use condoms

Question 30

summary for gonorrhea

Answer 30

- virulence factors- IgA protease, pili, LOS, porins, opa - gram neg diplococci, aerobic/facultative, human restricted, oxidase positive, catalse positive - growth inhibited on blood agar and overgrown by normal flora on non-selective media- use thayer martin if normal flora (genital, nasopharyngeal), chocolate if normally sterile (CSF, blood) - host defends with IgG enhanced complement and PMNs, usually contains gonococcus - complement deficiency predisposes to complications - asymptomatic/ untreated leads to PID in women - other serious complications follow bactermia-DGI, septic arthritis, meningitis, endocard - neonates must be protected by prophylactic eye ointment - test with culture and gram stain of appropriate samples, DNA testing available - condoms are effective protection when used correctly - treat with ceftriaxone, cefotaxime, admit if complications

Question 31

summary for chlamydia

Answer 31

- small, obligate intracellular bacterium - replicate with elementary bodies and reticulate bodies - 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 - unusual life cycle complicates research- one known virulence factor is T3SS used for entry and est inclusion body - causes LV, blinding trachoma, and pneumonia in addition to urogenital infection - treatment can often be started based on clinical findings, additional diagnostics are available and may be desired in various situations - treat with tetracyclines unless contraindicated- test after treatment - condoms are effective protection when used correctly