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Chlamydophila pneumoniae; Chlamydia pneumoniae (TWAR agent)

Epidemiology: 1) found primarily in human respiratory tract - > cardiovascular tissues, peripheral blood mononuclear cells - > brain, liver, spleen, lymph nodes, & bone marrow. [5,6] - retina [6] 2) no known reservoirs 3) person to person spread 4) cycles of disease every few years 5) re-infection is common 6) 10% of community-acquired pneumonia Pathogenesis: 1) causes a spectrum of disease: -> mild upper respiratory tract symptoms to pneumonia 2) considered an etiologic agent of coronary artery disease 3) may be etiologic agent of Alzheimer's disease (AD) [6] - associated with retinal includions in patients with AD [6] Clinical manifestations: 1) incubation period 10-65 days 2) 15% of patients are symptomatic a) pharyngitis (90%) b) pneumonia (10%) c) bronchitis (5%) d) sinusitis (5%) e) pharyngeal erythema (common) f) wheezing (common) Laboratory: - obligate intracellular bacteria - Chlamydophila pneumoniae serology - complement fixation: insensitive & non-specific - Chlamydophila pneumoniae antigen - Chlamydophila pneumoniae DNA, Chlamydophila pneumoniae rRNA - Chlamydophila pneumoniae+Chlamydophila psittaci DNA - culture for Chlamydophila pneumoniae - see ARUP consult [4] Pharmacology: - antimicrobial susceptibility - macrolides, tetracyclines, & fluoroquinolones (primary) [7,8] - beta-lactams are not effective [9] Radiology: -> chest X-ray: unilateral, segmental, patchy opacity Management: (antimicrobial therapy) 1) tetracycline 500 mg PO QID 2) doxycycline 100 mg IV/PO BID 3) macrolide a) erythromycin b) clarithromycin c) azithromycin

General

Chlamydophila

Properties

KINGDOM: monera DIVISION: SCHIZOMYCETES

References

  1. Manual of Medical Therapeutics, 28th edition, Ewald & McKenzie (eds) Little, Brown & Co, 1995, pg 301-302
  2. Mayo Internal Medicine Board Review, 1998-99, Prakash UBS (ed) Lippincott-Raven, Philadelphia, 1998, pg 798
  3. Journal Watch 20(14):111, 2000 Ericson et al Circulation 101:2568 2000
  4. ARUP Consult: Chlamydophila Species - Chlamydia pneumoniae Infection The Physician's Guide to Laboratory Test Selection & Interpretation https://www.arupconsult.com/content/chlamydophila-species
  5. Roulis E, Bachmann NL, Myers GS et al Comparative genomic analysis of human Chlamydia pneumoniae isolates from respiratory, brain and cardiac tissues. Genomics. 2015 Dec;106(6):373-83. PMID: 26420648 Free article. https://www.sciencedirect.com/science/article/pii/S0888754315300343?
  6. Gaire BP, Koronyo Y, Vit JP et al Identification of Chlamydia pneumoniae and NLRP3 inflammasome activation in Alzheimer's disease retina. Nat Commun. 2026 Jan 22;17(1):771. PMID: 41571675 PMCID: PMC12827417 Free PMC article. https://pmc.ncbi.nlm.nih.gov/articles/PMC12827417/
  7. Burillo A, Bouza E. Chlamydophila pneumoniae. Infect Dis Clin North Am. 2010 Mar;24(1):61-71. PMID: 20171546 Review.
  8. Blasi F, Tarsia P, Aliberti S. Chlamydophila pneumoniae. Clin Microbiol Infect. 2009 Jan;15(1):29-35. PMID: 19220337 Free article. Review.
  9. Taavitsainen-Wahlroos E, Reigada I, Sulmona I, Hanski L. Impact of azithromycin, doxycycline and redox-active small molecules on amoxicillin-induced Chlamydia pneumoniae persistence. Biomed Pharmacother. 2023 Nov;167:115451. PMID: 37690390 Free article. https://www.sciencedirect.com/science/article/pii/S0753332223012490