Chlamydia Flashcards

1
Q

What are the bacteriological features of Chlamydia?

A
•	Gram negative bacteria
•	Obligate intracellular pathogens
-needs the host’s ATP as an energy source for their own cellular activity
–	Are very small (0.5 in diameter 
–	I.E. NEED LIVING CELLS TO SURVIVE 
–	IF YOU WANT TO CULTURE THEM NEED LIVING CELLS TOO!
–	Spreads person to person
–	Cell wall but not peptidoglycan
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2
Q

What is the unique characters of Chlamydia cell wall?

A

Chlamydia - The unique cell wall of Chlamydia trachomatis is thought to be one of its virulence factors, as it inhibits phagolysosome fusion in phagocytes. The cell wall contains an outer lipopolysaccharide membrane but lacks peptidoglycan. It instead contains cysteine-rich proteins that are likely the functional equivalent of peptidoglycan. This unique cell wall structure, allows for intracellular division and extracellular survival.

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3
Q

What are the two forms of Chlamydia ?

A
  1. Elementary body

2. Reticulate body

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4
Q

What is elementary body of Chlamydia ?

A

– The infectious particle – is metabolically inactive
– Tough membrane allows it to survive outside host cells
– Taken into the host cell by phagocytosis; a vacuole (the phagosome), derived from the host cell membrane forms around the particle

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5
Q

What is reticulate body of Chlamydia ?

A
Resemble bacteria in that they:
•	Possess RNA and DNA
•	multiply by binary fission
•	have a rigid cell wall
•	possess a number of enzymes
•	are susceptible to some anti-bacterials
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6
Q

Which Chlamydia species are in respiratory tract?

A

Chlamydia pneumoniae

Chlamydia psittaci

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7
Q

How can Chlamydia pneumoniae spread?

A

Person to person spread – Inhalation

Outbreaks in nursing homes

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8
Q

What is the clinical presentation of Chlamydia pneumoniae?

A
–	Pneumonia -preceded by pharyngitis
–	Extra pulmonary manifestations 
•	Meningoencephalitis
•	Guillain-Barre syndrome
•	Reactive arthritis
•	Myocarditis
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9
Q

How can C. psittaci be spread?

A

(ZOONOSIS) Inhalation of dried infected droppings and/or secretions
– Hx contact with infected birds usually (live or dead!)
– Outbreaks: pet shops, aviaries, veterinary hospital, poultry flocks, turkey and duck processing

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10
Q

What is the clinical presentation of C. psittaci?

A
  • Acute onset of malaise, fever, anorexia, sore throat, photophobia and severe headache
  • Atypical pneumonia – lobar changes on CXR
  • Complications rare but severe

– Respiratory failure, hepatitis, endocarditis, and encephalitis.
– Infection in pregnancy may be life threatening

Atypical pneumonia due to psittacosis: The family had recently purchased several parrots

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11
Q

What is the diagnosis of C. Pneumoniae and C. Psittaci?

A
  • Nucleic acid amplification testing
  • Serology to detect specific IgG
  • 4 fold rise in titre
  • [cell culture] Obligate intracellular pathogens, i.e. need living cells to survive
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12
Q

What is the treatment of Pneumoniae and C. Psittaci?

A

• Tetracycline or macrolides
(Doesn’t have peptidoglycan in cell wall – penicillin no use!)
• Mortality as high as 20% in untreated infection, especially in elderly.

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13
Q

Which Chlamydia species are in eyes, respiratory tract, genitals?

A

Chlamydia trachomatis

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14
Q

What is the clinical presentation of Chlamydia trachomatis in eye?

A

• Trachoma
– Serovar A, B1, B2, C
• Inclusion conjunctivitis (adults, neonatal conjunctivitis)
– Serovars D to K

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15
Q

What is the clinical presentation of Chlamydia trachomatis in respiratory tract?

A

• Neonatal pneumonia

– Serovars D to K

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16
Q

What is the clinical presentation of Chlamydia trachomatis in genitals?

A

• Sexually transmitted infection (urethritis / cervicitis)
– Serovars D to K
• Lymphogranuloma venereum
– Serovars L1, L2, L3

17
Q

What is trachoma?

A

C. Trachomatis Serovar A, B1, B2, C: trachoma
Trachoma is hyperendemic in many of the poorest and most rural areas of 41 countries of Africa, Central and South America, Asia, Australia and the Middle East.
It is responsible for the blindness or visual impairment of about 1.9 million people. It causes about 1.4% of all blindness worldwide.

18
Q

What is epidemiology of trachoma?

A

• Chronic follicular keratoconjunctivitis
• Leading infectious cause of blindness worldwide
– Worldwide, over 80 million people have active trachoma, over 7 million have trichiasis (ingrown eyelashes), and over 1 million have blindness due to corneal scarring
• Young children: Active infection
• Adults: scarring and blindness (cicatricial disease)

19
Q

How can trachoma spread?

A

Contact
– Direct (eye, nose, throat secretions).
– Indirect (fomites contaminated with secretions - handkerchiefs, towels, flies)

20
Q

What is Pannus?

A

Pannus is the growth of fibrovascular tissue over the cornea as a result of oedema and ulceration due to eyelash abrasion on the cornea.

21
Q

What is the diagnosis of trachoma ?

A

Clinical

22
Q

What is the treatment of trachoma ?

A

SAFE
– Surgical correction of trichiasis (ingrown eyelashes) prevents development of corneal opacification,
– Antibiotics (azithromycin / tetracycline)
– Facial cleanliness
– Environmental improvements may disrupt the cycle of reinfection.

23
Q

What is inclusion conjunctivitis?

A

The eye discharge in Inclusion Conjunctivitis, whether in an infant or at any other age, is typically serosanginous or mucopurulent, and not purulent and/or yellow. If it is purulent and/or yellow this means that there is also infection, or superinfection with a pyogenic organism e.g., the gonococcus or the staphylococcus.

24
Q

How can inclusion conjunctivitis spread?

A

Contracted in birth canal during labour

25
Q

What is the clinical presentation of inclusion conjunctivitis?

A
  • Conjunctival inflammation – serosanginous or mucopurulent discharge + swelling of eyelids 5-14 days post partum
  • Pneumonia may also be present
26
Q

What is the diagnosis of inclusion conjunctivitis?

A

Conjunctival scraping – antigen detection / nucleic acid amplification testing (NAAT)

27
Q

What is the treatment of inclusion conjunctivitis?

A

– Macrolide (azithromycin) or doxycycline (not child)

– Treat mum + partner also

28
Q

What are the clinical presentations of genital tract infections of Chlamydia trachomatis in females?

A

Cervicitis
Majority asymptomatic.
• Non specific symptoms (discharge / inter-menstrual or post coital bleeding)

  • 25% urethritis (often misdiagnosed as UTI – dysuria, frequency)
  • If ascends = Pelvic inflammatory disease (abdominal/pelvic pain)
  • Complications of pregnancy (PROM / preterm delivery / transmission to new-born baby)
29
Q

What are the clinical presentations of genital tract infections of Chlamydia trachomatis in males?

A

Urethritis
• Approx. half have symptoms – urethral discharge + dysuria

Acute epididymitis
• Unilateral testicular pain and tenderness, hydrocele, and palpable swelling of the epididymis.

• Proctitis

30
Q

What is the diagnosis of genital tract infections of Chlamydia trachomatis?

A

nucleic acid amplification testing (NAAT) vulvo-vaginal swabs / endo-cervical swabs/ first-catch urine/ urethral swabs/ rectal swabs

31
Q

What is the treatment of genital tract infections of Chlamydia trachomatis?

A
  • Macrolide or doxycycline
  • Treat the partners too
  • Check for other causes of STI
32
Q

What is Lymphogranuloma venereum (LGV)?

A

• C. trachomatis serovars L1-L3
• Commonest in the tropics
Clinical presentation – genital ulcer followed by lymphadenopathy of the regional lymph nodes (buboes)

33
Q

What is the diagnosis of Lymphogranuloma venereum (LGV)?

A
  • NAAT of aspirated fluid

* Serology

34
Q

What is the treatment of Lymphogranuloma venereum (LGV)?

A
  • Aspirate buboes
  • Doxycycline (3 weeks)
  • Treat the partners too
  • Check for other causes of STI
35
Q

What’s you diagnosis? 52 year old vet: Acute onset malaise, fever, anorexia, sore throat, photophobia and severe headache
Few days later respiratory symptoms

A

Psittacosis

36
Q

What’s you diagnosis? 20 year old female: New partner – unprotected sex in last 12 weeks
Abdominal pain / nausea / fever
Laparotomy: tubo-ovarian abscess / salpingitis/ perihepatitis

A

Fitz hugh curtis

37
Q

What’s you diagnosis? 72 year old nursing home resident: Headache and myalgia 10 days ago – persistent dry cough since

A

C pneumoniae but could be lots of things!

38
Q

What’s you diagnosis? 7 day old neonate: Purulent yellow eye discharge
Rapid breathing + cough

A

C trachomatis pneumonia / conjunctivits