Chlamydia Flashcards
The Gram reaction of chlamydiae
negative or variable and is not useful in identification of the agents.
It has a relatively high lipid content. including lipopolysaccharide of low endotoxic activity. It is rigid but does not contain a typical bacterial peptidoglycan
Chlamydia
Infectious particle (transmissible form) of chlamydia
elementary body (EB)
Ddvelopmental cycle of chlamydia
48-78 hrs
Commonly are used to isolate chlamydiae
McCoy cells treated with cycloheximide
Grows better in HL or HEp-2 cells
C pneumoniae grows
All types of chlamydia proliferate in
embryonated eggs, particularly in the yolk sac
Major diseases of C trachomatis
Trachoma, STDs, infant pneumonia, LGV
Serovars of Chlamydia psittaci
> _ 4
Serovars of C trachomatis and C pneumonia
15 and 1 respectively
Natural host of C pneumoniae
Human, animals
Causes chronic keratoconjunctivitis (Trachoma)
C trachomatis
Serovars associated with Trachoma
Serovars A, B, Ba, C
Incubation period of C trachomatis
3-10 days
Earliest symptoms of trachoma
- Lacrimation,
- mucopurelent discharge,
- conjunctival hyperemia, and
- follicular hypertrophy
Microscopic examination of the cornea reveals
- epithelial keratitis,
- subepithelial infiltrates,
- extension of limbal vessels into the cornea (pannus)
Diagnostic culture of C trachomatis
- Inoculation of conjunctival scrapings into cycloheximide treated McCoy cell after 2–3 days of incubation.
- Typical cytoplasmic inclusions are found in epithelial cells of conjunctival scrapings stained with fluorescent antibody or by the Giemsa method
The most sensitive method for their detection in serology
Immunofluorescence
Treatment for C trachoma
Azithromycin
Prevention of C trachoma
S-A-F-E program:
• surgery for deformed eyelids,
• periodic azithromycin therapy,
• face washing and hygiene
• environmental improvement such as building latrines and
decreasing the number of flies that feed on conjunctival exudates
Cause sexually transmitted diseases
C trachomatis serovars D–K
C trachomatis serovars D–K causes in men….
Causes nongonococcal urethritis and, occasionally, epididymitis
C trachomatis serovars D–K causes in women….
Causes urethritis, cervicitis, and pelvic inflammatory disease, which can lead to sterility and predispose to ectopic pregnancy.
May occur in men and women in CHLAMYDIA TRACHOMATIS GENITAL INFECTIONS
Proctitis and proctocolitis
30–50% of infants of infected mothers acquire the infection, with 15–20% of infected infants manifesting eye symptoms and 10–40% manifesting respiratory tract involvement
Inclusion conjunctivitis of the newborn
Used to scrape epithelial cells from 1–2 cm deep into the endocervix of C trachomatis infection
swab or cytology brush
Swab specimens should be placed in a chlamydiae transport medium,
such as ______________ that inhibit normal microbiota, and kept at refrigerator temperature.5
2-sucrose phosphate supplemented with bovine serum and antibiotics
Can be tested for the presence of chlamydial nucleic acid.
Urine
Are the tests of choice for the diagnosis of genital C trachomatis infections.
Nucleic acid amplification tests-
Treatment for non-gonococcal urethritis
Tetracyclines (eg, doxycycline)
Treatment for pregnant women CHLAMYDIA TRACHOMATIS GENITAL INFECTIONS
Azithromycin
Treatment for Inclusion Conjunctivitis
Systemic therapy because topical therapy may not cure the eye infections or prevent respiratory disease.
Prevention: CHLAMYDIA TRACHOMATIS GENITAL INFECTIONS
Depends on safe sex practices and on early diagnosis and treatment of infected persons.
newborns infected by the mother, 10–20% may develop respiratory tract
involvement 2–12 weeks after birth.
NEONATAL PNEUMONIA (caused by C trichomatis)
Signs: NEONATAL PNEUMONIA
- nasal obstruction or discharge,
- striking tachypnea,
- a characteristic paroxysmal staccato cough,
- absence of fever, and
- eosinophilia.
Diagnosis: NEONATAL PNEUMONIA
➢Interstitial infiltrates and hyperinflation can be seen on radiographs
➢immunoglobulin M (IgM) antibody titer to C trachomatis of 1:32 or more is
considered diagnostic
Treatment: NEONATAL PNEUMONIA
- Oral erythromycin for 14 days is recommended
* systemic erythromycin is effective treatment in severe cases
is a sexually transmitted disease caused by C trachomatis and is characterized by suppurative inguinal adenitis.
LYMPHOGRANULOMA VENEREUM
LYMPHOGRANULOMA VENEREUM is caused by
three serovar antigens (L1–L3)
Contain CF heat-stable chlamydial group antigens t
LYMPHOGRANULOMA VENEREUM
Clinical features caused by LGV in men
- inguinal nodes are most commonly involved both above and below Poupart’s ligament
- the overlying skin often turns purplish as the nodes suppurate (bubo formation)
- eventually discharge pus through multiple sinus tracts.
Clinical features caused by LGV in women and homosexual men
- perirectal nodes are prominently involved, with proctitis
* a bloody mucopurulent anal discharge
Clinical Course of the disease:
• Days to several weeks after exposure, a small, evanescent papule or vesicle develops
on any part of the external genitalia, anus, rectum, or elsewhere.
• The lesion may ulcerate, but usually it remains unnoticed and heals in a few days.
• The regional lymph nodes enlarge and tend to become matted and painful
Detect all of the LGV serovars but cannot differentiate them from other C trachomatis serovars.
Nucleic Acid Amplification Tests
Suspected material of LGV is inoculated into
McCoy cell cultures
➢The inoculum can be treated with an __________ to lessen bacterial contamination. The agent is identified by morphology and serologic tests.
aminoglycoside (but not with penicillin)
The test becomes positive 2–4 weeks after onset of illness of LGV
Serology test
A rising antibody level or a single titer of more than ______ is good evidence of active infection.
1:64
Treatment: LGV
sulfonamides and tetracyclines
Pharyngitis is common. Sinusitis and otitis media may occur and be accompanied by
lower airway disease is caused by
CHLAMYDIA PNEUMONIAE
Is similar to that caused by Mycoplasma pneumoniae
Atypical pneumonia
Treatment: CHLAMYDIA PNEUMONIAE
- Macrolides ( Azithromycin, clarithromycin)
- Tetracyclines,
- some fluoroquinolones (Levofloxacin, moxifloxacin)
Little value due to insensitivity in diagnosing CHLAMYDIA PNEUMONIAE
Smears
Swab specimens of the pharynx of infected with C. pneumoniae should be put into ________ and grows better in _________ in _______ °
- chlamydiae transport medium and placed at 4°C
- HL and HEp-2 cells
- 35°C than 37°C. After 3 days incubation
The most sensitive method for diagnosis of C pneumoniae infection. The test is species specific and can detect IgG or IgM antibodies
Serology using the MIF test
Acquired from contact with birds and also the infection of psittacine
birds (eg, parrots, parakeets, cockatoos)
Psittacosis (C. psittaci)
Infection with similar agents in all types of domestic birds (eg, pigeons, chickens,
ducks, geese, turkeys) and free-living birds (eg, gulls, egrets, petrels)
Ornithosis
Causes a patchy inflammation of the lungs in which consolidated areas are
sharply demarcated. The exudates are predominantly mononuclear.
Psittacosis
Clinical findings
- Exposure to birds/bird droppings→ The incubation period averages 10 days→ sudden onset of illness taking the form of influenza or nonbacterial pneumonia
- malaise,
- fever,
- anorexia,
- sore throat,
- photophobia,
- severe
- headache
Not recommended because of the biohazard risk ( Should be done in a
Biosafety level III) in Psittacosis.
Culture
Is one with a positive culture result or associated with a compatible clinical illness
plus a fourfold or greater change in antibody titer to at least 1:32 or a single MIF IgM titer of at least 1:16
confirmed case
Treatment: Psittacosis.
- Doxycycline and tetracycline
* macrolides and fluoroquinolones- may be alternatives
