Chlamydia Filename Chlamydia ppt 1 1252020 Chlamydia 2

Chlamydia Filename: Chlamydia. ppt 1 12/5/2020

Chlamydia 2 12/5/2020

Chlamydia Obligate intracellular coccoid parasites n contain DNA and RNA, and ribosomes n lack ATP, biosynthetic pathways n cell wall but peptidoglycan absent n – use disulfide bonds n 3 non motile 12/5/2020

Obligate Parasites n Obligate intracellular parasites of mammals and birds – not transmitted by arthropods. – incorrectly called the PLT viruses or Bedsonia or basophilic viruses, n Multiply in the cytoplasm of the host cell. – generally epithelial cells – Basophilic inclusions 4 12/5/2020

Similar to Viral Infections The methods used to study Chlamydia are those of the virologist rather than the bacteriologist. n The clinical features, pathogenesis, pathology and epidemiology of chlamydial infections are similar to those of viral infections. n 5 12/5/2020

Energy Parasites The cells can synthesize DNA, RNA and protein. n No flavoproteins or cytochromes. n lack of ATP-generating ability n need to obtain ATP from the host cell. n 6 12/5/2020

Three species: C. trachomatis C. psittaci C. pneumoniae 7 12/5/2020

Ecology Chlamydia form two main ecological groups. n Infect only humans n – Subgroup A – trachoma, inclusion conjunctivitis, and lymphogranuloma venereum n Zoonotic Infections – Subgroup B – Respiratory tract infections 8 12/5/2020

Zoonotic Infections transmitted to man n About 100 species of birds are naturally infected with chlamydia. n – 71 species of parrots – finches, pigeons, chickens, ducks, turkeys and seabirds. 9 12/5/2020

C trachomatis Trachoma conjunctivitis proctitis urethritis salpingitis Lymphogranuloma venereum C psittaci & C pneumoniae Upper respiratory infection Bronchitis Pneumonia 10 12/5/2020

Chlamydial Morphologies n Elementary body – 0. 25 - 0. 3 um diameter – electron-dense nucleoid – Released from ruptured infected cells. Human to human – & bird to human. n Reticulate Body – Intracytoplasmic form 0. 5 - 1. 0 um – Replication and growth. ( Inclusion body ) – without a dense center. 11 12/5/2020

Developmental Cycle of Chlamydia 12 12/5/2020

13 C trachomatis elementary bodies 12/5/2020

C trachomatis inclusions Glycogen Inclusions 14 12/5/2020

Subgroups n n n Subgroup A Mammalian parasites Compact inclusions Glycogen synthesized Folates synthesized n n n – Sensitive to D-cycloserine n n 15 Restricted host range Chlamydia trachomatis Subgroup B Primarily bird parasites Diffuse inclusions Glycogen not synthesized Folates not synthesized – Resistant to D-cycloserine n n Broadening of host range Chlamydia psittaci 12/5/2020

Evolution of Chlamydia Gram-negative cocci n Facultative intracellular parasites of mammals n Obligate intracellular parasites n Host range restricted to rodents n Restricted virulence (compact inclusions) n Folates synthesized (sulfonamide susceptible) n Glycogen synthesized and deposited in inclusions n 16 12/5/2020

Conjunctivitis n Inclusion conjunctivitis: – Transmitted by infectious secretions of the genitourinary tract – autoinoculation n Infantile conjunctivitis: – Acquired in the birth canal -- 5 -12 days after birth – most common type of conjunctivitis n 17 Antibiotic prophylaxis: erythromycin, tetracycline. 12/5/2020

Chlamydial Infection of Ocular Conjunctiva 18 12/5/2020

Trachoma n infection of conjunctival epithelial cells. – subepithelial infiltration of lymphocytes. – Infected epithelial cells contain cytoplasmic inclusion bodies – Cell infiltrations to cornea cause clouding n 19 Trichiasis: abnormal inward growth of eyelashes. 12/5/2020

Predisposing factors: climate - hot , dry n shortage of water n standards of hygiene low Transmitted by flies, dirty towels, fingers, cosmetic eye pencils. Initial infection in childhood mostly by 1015 years of age. n 20 12/5/2020

Trachoma n 21 Almost six million people have become blind another 540 million almost 10% of the world’s population are at risk 12/5/2020

Trachoma Incidence 22 12/5/2020

Chlamydia trachomatis Clinical disease lymphogranuloma venereum n nongonoccal urethritis (NGU) n epididymitis n salpingitis n mucopurulent cervicitis n pelvic inflammatory disease (PID) n Reiter's syndrome n neonatal chlamydia 23 n 12/5/2020

Chlamydia: Rates by Gender 24 12/5/2020

Chlamydia Symptoms In Men n 25 Symptoms usually appear between 7 and 28 days after infection, usually with mild burning when urinating, a more frequent need to urinate, and a white discharge from the penis. Occasionally, blood may appear in the urine. The symptoms occur most frequently in the morning. 12/5/2020

Erythematous meatus and urethra with balanitis Hyperlink to original 26 12/5/2020

Chlamydial Urethritis in Males 27 12/5/2020

Nongonococcal urethritis (NGU) Reiter's syndrome n 28 Swollen, painful right knee in which needle aspiration for synovial fluid was performed (yellow discoloration from the betadine prep) Hyperlink to original site 12/5/2020

Lymphogranuloma venereum LGV 200 reported cases per year. n Incubation period is 5 to 20 days. n Lesion: Transient vesicles on penis or vagina that are often unnoticed and patients do not usually seek medical advice. n 29 12/5/2020

Bilateral inguinal adenopathy with overlying erythema R 30 Roberts MD 12/5/2020

LGY: "Groove sign" n Pompart's ligament is preserved despite the involvement of multiple inguinal nodes R Roberts MD 31 12/5/2020

LGV: Microscopy n lymph node shows both necrosis and granulomatous reaction (dimorphic necrotizing granulomatous reaction) R Roberts MD 32 12/5/2020

Chlamydia pneumoniae This bacterium was first recognized in 1983 as a respiratory pathogen, after isolation from a college student with pharyngitis. n Pneumonia or bronchitis, gradual onset of cough with little or no fever. Less common presentations are pharyngitis, laryngitis, and sinusitis. n 33 12/5/2020

Incidence n 34 Each year an estimated 50, 000 adults are hospitalized with pneumonia in the United States. The overall incidence is unknown. 12/5/2020

35 12/5/2020

Transmission Person-to-person transmission by respiratory secretions. n Risk Groups n All ages at risk but most common in schoolage children. By age 20 years, 50% of population have evidence of past infection. Reinfection throughout life appears to be common. n 36 12/5/2020

C. pneumoniae Associations Associated with Heart Disease n infection may be associated with n – atherosclerotic vascular disease n Proposed Associations – Alzheimer's diseases, asthma, and reactive arthritis 37 12/5/2020

Treatment Chlamydia n 38 Adults Conjunctival, urethral, cervical, rectal: n Children < 45 kg, urogenital & rectal: – erythromycin 50 – Azithromycin 1 gm x 1 mg/kg/day in 4 doses for dose 10 -14 days – Doxycycline 100 mg BID n Neonates (ophthalmia, for 7 days infants born to infected – Ofloxacin 300 mg po BID for 7 days mothers): – Erythromycin 500 mg QID – erthromycin 50 mg/kg/day for 7 days in 4 doses for 10 -14 days – Amoxacillin 500 mg TID 710 days 12/5/2020

Chlamydia Antigens: group specific & species specific n Major outer membrane protein (cysteine -rich) n Eucaryotic cell binding protein Host response: damage to specific tissues 39 12/5/2020

Laboratory Diagnosis n Isolate the organism from infected tissue. – Inoculate the yolk sac of seven-day chick embryos – Inoculate Mc. Coy human cells. n 40 Characteristic cytoplasmic inclusion bodies in infected cells. 12/5/2020

Immunofluorecent tests n Microimmunofluorescent tests – patients with eye infections – Check tears for the presence of anti-chlamydia antibody. n 41 Direct immunofluorescence – of conjunctive cells with fluorescein conjugated monoclonal antibody is sensitive and specific. – In neonatal conjunctivitis and early trachoma 12/5/2020

Serological diagnosis: Immunofluorecent tests n Delayed Type Skin Reaction n Antibodies to Family antigen n 42 12/5/2020

FREI Test n 43 Delayed-type skin reaction to killed organisms in genitourinary infections 12/5/2020

Antibodies to Family antigen n Rising titer of antibody against the chlamydial family antigen in lung infections. – Complement fixation test – Fluorescent antibody test. 44 12/5/2020

DONE!!! 45 12/5/2020