Chlamydia: STD, Symptoms & Diagnosis - PDF

HIND ABDULMAJED, PHD D E PA RT M E N T O F M E D I C A L M I C RO B I O L O GY & PA R A S I TO LO GY FAC U LT Y O F M E D I C I N E H A B D U L M A J E D @ K AU. E D U. SA https://youtu.be/tyBPshaQcSU?si=ctVF- dp-3t1QQaa- Chlamydia Transmission STD Asymptomatic...

HIND ABDULMAJED, PHD D E PA RT M E N T O F M E D I C A L M I C RO B I O L O GY & PA R A S I TO LO GY FAC U LT Y O F M E D I C I N E H A B D U L M A J E D @ K AU. E D U. SA https://youtu.be/tyBPshaQcSU?si=ctVF- dp-3t1QQaa- Chlamydia Transmission STD Asymptomatic Specimen in females r collection Curable by PID antibiotics Chlamydia trachomatis Structurally is Gram negative Have LPS No peptidoglycan Pelvic Inflammatory Disease (PID) 2 organisms known to cause PID: Neisseria gonorrhoeae Chlamydia trachomatis  Case Study 21 year old female, complaint of ongoing abdominal pain for days and vaginal bleeding. No nausea or vomiting. Denied UTI symptoms. Upon examination, tenderness in the upper right & lower left quadrants of the abdomen. Had a fever of 38.3°C. Cervical motion tenderness present upon pelvic examination + right & left ovary tenderness. LABORATORY EXAMINATION Endocervical swab obtained from patient to inoculate McCoy cells. After incubation, cells were stained and showed the presence of inclusions. Obligate intracellular bacteria The Diagnosis Case Study After results from the physical and the laboratory examination showing the presence of elementary and reticulate bodies in inoculated cells. It was found that Chlamydia trachomatis was the causative agent.  Gram-negative cell wall with Cannot produce their own LPS (weak endotoxic activity) ATP (require but lack peptidoglycan layer host) Chlamydia Two morphological forms (Dimorphic): Characteristics & 1. Elementary body (EB): 300-350 nm Morphology 2. Reticulate body (RB): 800-1000 nm So…. What makes Chlamydia Unique?  Chlamydiae are microorganisms exhibiting characteristics intermediate between bacteria and viruses Character Chlamydia Bacteria Viruses Cell Wall Like Gram -ve cell wall Rigid No cell wall NO PG Have PG No PG Size Small ≤ 0.45µm Larger ≥ 0.45µm Small ≤ 0.45µm Nucleic acid RNA & DNA RNA & DNA RNA or DNA Cell Division Binary fission Binary fission None Ribosomes Present Present None Antibiotics Sensitive to many Sensitive to many Resistant Sensitivity Plasmids Present Present Absent DR. RAZINA GAMARZAMAN Character Chlamydia Bacteria Viruses Cell Wall Like Gram -ve cell wall Rigid No cell wall NO PG Have PG No PG Size Small ≤ 0.45µm Larger ≥ 0.45µm Small ≤ 0.45µm Nucleic acid RNA & DNA RNA & DNA RNA or DNA Cell Division Binary fission Binary fission None Ribosomes Present Present None Antibiotics Sensitive to many Sensitive to many Resistant Sensitivity Plasmids Present Present Absent DR. RAZINA GAMARZAMAN Chlamydia Dimorphic Life Cycle 4. RB divides repeatedly by binary fission forming inclusion bodies  Dimorphic Life Cycle 1. Elementary body (Eb) 2. Initial / Reticulate body (Rb) Small (300 nm), spherical (or pear shaped). Larger (800 - 1000 nm) Resistant form (tough, rigid spore like). Reproductive form. Replicate by binary fission. Metabolically inactive, Infectious form. Metabolically active, non-infectious form so cytoplasm rich in Extracellular ribosomes. Intracellular Contain “nucleoid” with compacted DNA Nucleic acid unlike EB is diffuse. (among smallest genomes in prokaryotes). RB synthesise their own DNA, RNA & protein but cannot make their own energy so known as “energy” parasites. Bind to receptors on host cells (affinity for Nature of inclusion bodies (presence of glycogen) varies epithelial cells in mucous membranes of with species. genital tract & respiratory tract). Taken up by phagocytosis. After replication are re-organised into EB and released from the cell by lysis of the host cell. Remain in cytoplasmic phagosomes and Phagosomes that contain the RB are known as inclusion bodies are detected by special stains. Antigens / Virulence Factors Shared group antigens Species specific antigens Heat stable Outer membrane proteins. Lipopolysaacharides. Virulence due to Damage in ability to survive trachoma due intracellularly. to repeated infections. Classification of Chlamydia Character C. trachomatis C. psittaci C. pneumoniae Host Humans Bird Humans Transmission Person to person From Birds Person to person Diseases Ocular/ Genital/ Respiratory Respiratory Respiratory Sulphonamide Sensitive Resistant Resistant Glycogen Present None None Inclusions Round Variable,dense Round,dense Elementary body Spherical Spherical Pear/ Spherical Serotypes 15 1 1 Plasmids Present Present Absent DR. RAZINA GAMAR ZAMAN  Chlamydia trachomatis: Ocular Infections Trachoma Inclusion conjunctivitis Neonatal Inclusion Conjunctivitis (Paratrachoma) “Chlamydial Ophthamia neonatarum Serotypes A, B, and C D-K -- Symptoms Lacrimation, muco-purulent discharge & Follicular conjunctivitis with Muco-purulent discharge, presence of lymphoid follicles in conjunctiva. muco-purulent discharge. swelling of the eye lids and Mechanical abrasion with in-turned eye lids orbit. Untreated leads to leads to scarring of conjunctiva, corneal conjunctival scarring & ulceration, pannus formation (invasion of corneal vascularisation. vessels into the cornea). Infections Repeated infections often lead to Disease is milder often self Often nasopharyngeal blindness. limiting and rarely infections. Secondary bacterial infections play role in loss of vision. causes blindness. Pneumonia may occur in Disease mainly in patients of low economic Repeated infection is less some babies. status. common. Remarks - Ancient disease. Mainly in hot climates. - Often sexually active adults - Babies born to mothers Trachoma belt (Middle East, North Africa and (18-30 years). Often with genital infection. India). - Most prevalent in children. Incidence following genital infection. - 7-14 days after birth. decreases in older children incidence of - Spread from genitalia to blindness continues to increase in older age eye (fingers) groups. Gift of Sight: Finding cures for blinding eye diseases www.giftofsight.org.uk/ OneSight https://onesight.org/ Give the Gift of Sight www.givethegiftofsight.com/ OneSight | LensCrafters www.lenscrafters.com/onesight Gift of Sight | Sightsavers www.sightsavers.org/gift-of-sight/ OneSight: Giving the Gift of Sight for 25 Years | Luxottica www.luxottica.com/en/onesight-giving-gift-sight-25-years-0  Chlamydia trachomatis Respiratory Infections: (Infant) Pneumonia o Variable incubation period often 2-3 weeks after birth. o Mostly acquired from mother during birth conjunctival infection leads to pneumonia. o Common also in hospitalized babies, can be acquired in nursery. o Infants develop rhinitis and cough but remain afebrile. DR. RAZINA GAMAR ZAMAN  Chlamydia trachomatis: Genital Infections Infections in males Infections in females Lymphogranuloma venereum Serotypes D-K D-K L1-L3 Symptomatic Asymptomatic Symptomatic (about 75- 80%) Characteristics Produce dual infections 1ry lesion at site of infection usually with N. gonorrhea. 50% small, painless often heals rapidly. non-gonococcal urethritis (NGU) is caused by C. trachomatis. Symptoms Urethral discharge Mucopurulent - Fever, headache, myalgia, chills & discharge anorexia. - Spreads to lymph nodes, with inflammation & swelling. - Produce painful buboes which may rupture & produce draining fistulas.  Chlamydia trachomatis Genital Infections Infections in males Infections in females Lymphogranuloma venereum Manifestation May progress to Cervicitis, endometritis, Untreated may develop epididymitis. Chronic urethritis & into chronic ulcerative infections may lead to salpingitis. disease & may lead to infertility. May be associated with PID genital elephantiasis  Chlamydia trachomatis Laboratory Diagnosis 1. Clinical diagnosis. 2. Specimens: Urethral or cervical scrapings. Conjunctival discharge. 3. Microscopy: Immunofluorescence or Giemsa staining. 4. Culture: Cell culture lines (McCoy), is difficult and time consuming. 5. Antigen Detection: DIF (fluorescein labelled antibodies) or ELISA. 6. Nucleic acid detection: by PCR, best results but expensive. 7. Serology: Presence of Ab does NOT always coincide with current infection. Important to check rising titre. 8. Frei skin test: Intra-dermal skin test. Delayed type hypersensitivity reaction. DR. RAZINA GAMAR ZAMAN  Chlamydia trachomatis Treatment o Tetracycline or Doxycycline in adults. o Erythromycin or Azithromycin in babies or children. o In females with chronic or ascending infections treatment for 3 weeks recommended. o In babies with ophthalmia neonatarum, the organism is also in the nasopharynx and require oral erythromycin with topical eye drops. DR. RAZINA GAMAR ZAMAN Chlamydia psittaci Transmission Zoonotic, from birds (parrots) to humans through the inhalation of dried bird excrement, urine, or respiratory secretions. Person-to-person transmission is rare Symptoms - Mild flu like illness (fever, rigors, malaise, headache & sore throat) to severe disease with pneumonia - CNS involvement is common, usually consisting of: Headache Encephalitis: convulsions & coma may occur in severe cases - Other signs are: Hepatomegaly & Splenomegaly Manifestation Psittacosis or Ornithosis= Parrot fever Laboratory Specimen: Sputum, Microscopy: Fluorescent staining Diagnosis Culture: Tissue culture Show 4 fold rise in Ab titre by complement fixation test or indirect immunofluorescence Treatment Erythromycin or Tetracycline (doxycycline) Chlamydia psittaci Note: Other animals, such as sheep, cows, and goats, as well as humans can become infected.  Chlamydia pneumonia known as TWAR agent (Taiwan acute respiratory agent) Transmission person to person Symptoms Respiratory tract disease. Pharyngitis, laryngitis, bronchitis or pneumonia “atypical” pneumonia similar to Mycoplasma pneumoniae. Re-activation & re-infection common Laboratory Staining & culture difficult, serology more sensitive diagnosis Treatment Tetracycline or erythromycin or Quinolones (Levofloxacin). Summary of Clinical Infections of Chlamydial species Species Serotypes Diseases C. trachomatis A, B, C Trachoma (The leading cause D-K Inclusion conjunctivitis of preventable Male- Epididymitis, Urethritis, blindness in the Proctitis. world) Females- Cervicitis, Salphingitis, Infertility, Abortion, Stillbirth. Babies- Pneumonia & Conjunctivitis. L1, L2, L3 Lymphogranuloma venereum C. pneumoniae TWAR Pneumonia C. psittaci 1 only Psittacosis DR. RAZINA GAMAR ZAMAN  Useful Links http://www.ncbi.nlm.nih.gov/books/NBK8091/?report=printable Chlamydiae: Chapter 17, p177-184 UNIQUE.. YOU