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ChlamydiaChlamydia

Filename: Chlamydia.ppt

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ChlamydiaChlamydia

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ChlamydiaChlamydia

Obligate intracellular coccoid Obligate intracellular coccoid parasitesparasites

contain DNA and RNA, and contain DNA and RNA, and ribosomesribosomes

lack ATP, biosynthetic pathwayslack ATP, biosynthetic pathways cell wall but peptidoglycan absent -cell wall but peptidoglycan absent -

– use disulfide bondsuse disulfide bonds non motilenon motile

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Obligate Parasites Obligate Parasites

Obligate intracellular parasites of Obligate intracellular parasites of mammals and birdsmammals and birds– not transmitted by arthropods. not transmitted by arthropods. – incorrectly called the PLT viruses or Bedsonia incorrectly called the PLT viruses or Bedsonia

or basophilic viruses, or basophilic viruses, Multiply in the cytoplasm of the host cell. Multiply in the cytoplasm of the host cell.

– generally epithelial cellsgenerally epithelial cells– Basophilic inclusionsBasophilic inclusions

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Similar to Viral InfectionsSimilar to Viral Infections

The methods used to study The methods used to study Chlamydia are those of the Chlamydia are those of the virologist rather than the virologist rather than the bacteriologist. bacteriologist.

The clinical features, pathogenesis, The clinical features, pathogenesis, pathology and epidemiology of pathology and epidemiology of chlamydial infections are similar to chlamydial infections are similar to those of viral infections. those of viral infections.

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Energy Parasites Energy Parasites The cells can synthesize DNA, RNA and The cells can synthesize DNA, RNA and

protein. protein. No flavoproteins or cytochromes. No flavoproteins or cytochromes. lack of ATP-generating ability lack of ATP-generating ability need to obtain ATP from the host cell. need to obtain ATP from the host cell.

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Three species: Three species:

C. trachomatisC. trachomatis

C. psittaciC. psittaci

C. pneumoniaeC. pneumoniae

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Ecology Ecology

Chlamydia form two main ecological groups. Chlamydia form two main ecological groups. Infect only humans Infect only humans

– Subgroup ASubgroup A– trachoma, inclusion conjunctivitis, and trachoma, inclusion conjunctivitis, and

lymphogranuloma venereumlymphogranuloma venereum Zoonotic InfectionsZoonotic Infections

– Subgroup BSubgroup B– Respiratory tract infectionsRespiratory tract infections

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Zoonotic InfectionsZoonotic Infections

transmitted to mantransmitted to man About 100 species of birds are About 100 species of birds are

naturally infected with chlamydia.naturally infected with chlamydia.– 71 species of parrots71 species of parrots– finches, pigeons, chickens, ducks, finches, pigeons, chickens, ducks,

turkeys and seabirds. turkeys and seabirds.

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C trachomatisC trachomatisTrachoma

conjunctivitis

proctitis

urethritis

salpingitis

Lymphogranuloma venereum

C psittaci & C pneumoniae

Upper respiratory infection

Bronchitis

Pneumonia

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Chlamydial MorphologiesChlamydial Morphologies Elementary bodyElementary body

– 0.25 - 0.3 um diameter0.25 - 0.3 um diameter– electron-dense nucleoidelectron-dense nucleoid– Released from ruptured infected cells. Human Released from ruptured infected cells. Human

to humanto human– & bird to human.& bird to human.

Reticulate BodyReticulate Body – Intracytoplasmic form 0.5 - 1.0 umIntracytoplasmic form 0.5 - 1.0 um– Replication and growth. ( Inclusion body )Replication and growth. ( Inclusion body )– without a dense center. without a dense center.

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Developmental Cycle of Developmental Cycle of ChlamydiaChlamydia

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C trachomatisC trachomatis elementary elementary bodiesbodies

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C trachomatis inclusionsC trachomatis inclusions

Glycogen Inclusions

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SubgroupsSubgroups Subgroup ASubgroup A Mammalian parasitesMammalian parasites Compact inclusionsCompact inclusions Glycogen synthesizedGlycogen synthesized Folates synthesizedFolates synthesized

– Sensitive to D-cycloserineSensitive to D-cycloserine Restricted host range Restricted host range

Chlamydia trachomatisChlamydia trachomatis

Subgroup BSubgroup B Primarily bird parasitesPrimarily bird parasites Diffuse inclusions Diffuse inclusions Glycogen not Glycogen not

synthesizedsynthesized Folates not synthesizedFolates not synthesized

– Resistant to D-cycloserineResistant to D-cycloserine Broadening of host rangeBroadening of host range Chlamydia psittaciChlamydia psittaci

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Evolution of Chlamydia Evolution of Chlamydia Gram-negative cocci Gram-negative cocci Facultative intracellular parasites of mammals Facultative intracellular parasites of mammals

Obligate intracellular parasites Obligate intracellular parasites Host range restricted to rodents Host range restricted to rodents Restricted virulence (compact inclusions) Restricted virulence (compact inclusions) Folates synthesized (sulfonamide susceptible) Folates synthesized (sulfonamide susceptible) Glycogen synthesized and deposited in Glycogen synthesized and deposited in

inclusionsinclusions

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ConjunctivitisConjunctivitis Inclusion conjunctivitisInclusion conjunctivitis::

– Transmitted by infectious secretions of the Transmitted by infectious secretions of the genitourinary tractgenitourinary tract

– autoinoculationautoinoculation Infantile conjunctivitisInfantile conjunctivitis::

– Acquired in the birth canal -- 5-12 days after Acquired in the birth canal -- 5-12 days after birthbirth

– most common type of conjunctivitismost common type of conjunctivitis Antibiotic prophylaxis: erythromycin, Antibiotic prophylaxis: erythromycin,

tetracycline.tetracycline.

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Chlamydial Infection of Chlamydial Infection of Ocular Conjunctiva Ocular Conjunctiva

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TrachomaTrachoma infection of conjunctival epithelial infection of conjunctival epithelial

cells. cells. – subepithelial infiltration of lymphocytes.subepithelial infiltration of lymphocytes.– Infected epithelial cells contain Infected epithelial cells contain

cytoplasmic inclusion bodies cytoplasmic inclusion bodies – Cell infiltrations to cornea cause cloudingCell infiltrations to cornea cause clouding

Trichiasis:Trichiasis: abnormal inward growth of abnormal inward growth of eyelashes.eyelashes.

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Predisposing factors:Predisposing factors:

climate - hot , dryclimate - hot , dry shortage of watershortage of water standards of hygiene lowstandards of hygiene low

Transmitted by flies, dirty towels, Transmitted by flies, dirty towels, fingers, cosmetic eye pencils.fingers, cosmetic eye pencils.

Initial infection in childhood mostly Initial infection in childhood mostly by 10-15 years of age.by 10-15 years of age.

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TrachomaTrachoma

Almost six million people have become Almost six million people have become blind and another 540 million almost 10% blind and another 540 million almost 10% of the world’s population are at riskof the world’s population are at risk

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Trachoma IncidenceTrachoma Incidence

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Chlamydia trachomatisChlamydia trachomatisClinical diseaseClinical disease

lymphogranuloma venereum lymphogranuloma venereum nongonoccal urethritis (NGU) nongonoccal urethritis (NGU) epididymitisepididymitis salpingitissalpingitis mucopurulent cervicitismucopurulent cervicitis pelvic inflammatory disease (PID)pelvic inflammatory disease (PID) Reiter's syndromeReiter's syndrome neonatal chlamydianeonatal chlamydia

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Chlamydia: Rates by Chlamydia: Rates by GenderGender

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Chlamydia Symptoms In Chlamydia Symptoms In MenMen

Symptoms usually appear Symptoms usually appear between 7 and 28 days after between 7 and 28 days after infection, usually with mild infection, usually with mild burning when urinating, a burning when urinating, a more frequent need to more frequent need to urinate, and a white urinate, and a white discharge from the penis. discharge from the penis. Occasionally, blood may Occasionally, blood may appear in the urine. The appear in the urine. The symptoms occur most symptoms occur most frequently in the morning. frequently in the morning.

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Erythematous meatus and Erythematous meatus and urethra with balanitis urethra with balanitis

Hyperlink to original

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Chlamydial Urethritis in Chlamydial Urethritis in MalesMales

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Nongonococcal urethritis Nongonococcal urethritis (NGU) - Reiter's syndrome(NGU) - Reiter's syndrome

Swollen, painful right knee in which Swollen, painful right knee in which needle aspiration for synovial fluid was needle aspiration for synovial fluid was performed (yellow discoloration from the performed (yellow discoloration from the betadine prep) betadine prep)

Hyperlink to original site

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Lymphogranuloma venereum Lymphogranuloma venereum LGVLGV

200 reported cases per year. 200 reported cases per year. Incubation period is 5 to 20 days. Incubation period is 5 to 20 days. Lesion:Lesion: Transient vesicles on penis Transient vesicles on penis

or vagina that are often unnoticed or vagina that are often unnoticed and patients do not usually seek and patients do not usually seek medical advice. medical advice.

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Bilateral inguinal adenopathy Bilateral inguinal adenopathy with overlying erythema with overlying erythema

R Roberts MD

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LGY: "Groove sign" LGY: "Groove sign"

Pompart's Pompart's ligament is ligament is preserved preserved despite the despite the involvement of involvement of multiple multiple inguinal nodesinguinal nodes

R Roberts MD

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LGV: MicroscopyLGV: Microscopy lymph node lymph node

shows both shows both necrosis and necrosis and granulomatous granulomatous reaction reaction (dimorphic (dimorphic necrotizing necrotizing granulomatous granulomatous reaction) reaction)

R Roberts MD

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Chlamydia pneumoniaeChlamydia pneumoniae

This bacterium was first recognized This bacterium was first recognized in 1983 as a respiratory pathogen, in 1983 as a respiratory pathogen, after isolation from a college student after isolation from a college student with pharyngitis.with pharyngitis.

Pneumonia or bronchitis, gradual Pneumonia or bronchitis, gradual onset of cough with little or no fever. onset of cough with little or no fever. Less common presentations are Less common presentations are pharyngitis, laryngitis, and sinusitis. pharyngitis, laryngitis, and sinusitis.

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IncidenceIncidence

Each year an estimated 50,000 Each year an estimated 50,000 adults are hospitalized with adults are hospitalized with pneumonia in the United States. pneumonia in the United States. The overall incidence is unknown. The overall incidence is unknown.

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TransmissionTransmission

Person-to-person transmission by Person-to-person transmission by respiratory secretions. respiratory secretions.

Risk GroupsRisk Groups All ages at risk but most common in All ages at risk but most common in

school-age children. By age 20 years, school-age children. By age 20 years, 50% of population have evidence of 50% of population have evidence of past infection. Reinfection throughout past infection. Reinfection throughout life appears to be common.life appears to be common.

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C. pneumoniae C. pneumoniae AssociationsAssociations

Associated with Heart DiseaseAssociated with Heart Disease infection may be associated with infection may be associated with

– atherosclerotic vascular diseaseatherosclerotic vascular disease Proposed AssociationsProposed Associations

– Alzheimer's diseases, asthma, and Alzheimer's diseases, asthma, and reactive arthritisreactive arthritis

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Treatment ChlamydiaTreatment Chlamydia AdultsAdults Conjunctival, Conjunctival,

urethral, cervical, rectal: urethral, cervical, rectal: – AzithromycinAzithromycin 1 gm x 1 dose 1 gm x 1 dose– DoxycyclineDoxycycline 100 mg BID for 100 mg BID for

7 days7 days– OfloxacinOfloxacin 300 mg po BID for 300 mg po BID for

7 days7 days– ErythromycinErythromycin 500 mg QID 500 mg QID

for 7 daysfor 7 days– AmoxacillinAmoxacillin 500 mg TID 7- 500 mg TID 7-

10 days10 days

ChildrenChildren < 45 kg, < 45 kg, urogenital & rectal: urogenital & rectal: – erythromycin 50 erythromycin 50

mg/kg/day in 4 doses mg/kg/day in 4 doses for 10-14 daysfor 10-14 days

NeonatesNeonates (ophthalmia, (ophthalmia, infants born to infants born to infected mothers): infected mothers): – erthromycin 50 erthromycin 50

mg/kg/day in 4 doses mg/kg/day in 4 doses for 10-14 daysfor 10-14 days

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Chlamydia AntigensChlamydia AntigensChlamydia AntigensChlamydia Antigens

Antigens: group specific & species Antigens: group specific & species specificspecific

Major outer membrane protein Major outer membrane protein (cysteine-rich)(cysteine-rich)

Eucaryotic cell binding proteinEucaryotic cell binding protein

Host response: damage to specific Host response: damage to specific tissuestissues

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Laboratory Diagnosis Laboratory Diagnosis

Isolate the organism from infected tissue. Isolate the organism from infected tissue. – Inoculate the yolk sac of seven-day chick Inoculate the yolk sac of seven-day chick

embryos embryos – Inoculate McCoy human cells. Inoculate McCoy human cells.

Characteristic cytoplasmic inclusion Characteristic cytoplasmic inclusion bodies in infected cells. bodies in infected cells.

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Immunofluorecent testsImmunofluorecent tests

Microimmunofluorescent testsMicroimmunofluorescent tests – patients with eye infections patients with eye infections – Check tears for the presence of anti-Check tears for the presence of anti-

chlamydia antibody. chlamydia antibody. Direct immunofluorescence Direct immunofluorescence

– of conjunctive cells with fluorescein - of conjunctive cells with fluorescein - conjugated monoclonal antibody is sensitive conjugated monoclonal antibody is sensitive and specific. and specific.

– In neonatal conjunctivitis and early trachomaIn neonatal conjunctivitis and early trachoma

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Serological diagnosis:Serological diagnosis:

Immunofluorecent testsImmunofluorecent tests Delayed Type Skin ReactionDelayed Type Skin Reaction Antibodies to Family antigen Antibodies to Family antigen

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FREI TestFREI Test

Delayed-type skin reaction to Delayed-type skin reaction to killed organisms in genitourinary killed organisms in genitourinary infectionsinfections

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Antibodies to Family Antibodies to Family antigenantigen

Rising titer of antibody against the Rising titer of antibody against the chlamydial family antigen in lung chlamydial family antigen in lung infections. infections. – Complement fixation testComplement fixation test– Fluorescent antibody test. Fluorescent antibody test.

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