Micro presentation

Chlamydiophilia pneumoniae

Jordan Frandsen

Case Study:

A 7 year old female reports to her physician complaining of an ear ache, cough, and a sore throat. Upon physical examination the doctor noted a crackling, wheezing cough.

A throat culture was taken and revealed nothing.

A chest x-ray showed a left lower lobe pneumoniae

Blood was drawn for serologic testing while the patient received broad spectrum antibiotics

Serologic testing

The Microparticle Agglutination Assay revealed a titer of antibodies of 1:310

The serum immunoblot assay showed positive IgM and IgG against Chlamydiophilia pneumoniae.

Chlamydiophilia pneumoniae

Gram-negative coccoid

Non-motile, non-spore forming

Obligate Intracellular bacterium

Incubation period is about 21 days

Two forms in nature:Elementary Body- infectious particle

Reticulate Body- engages replication and growth

Clinical Presentation

Symptoms can range from asymptomatic to severe

Mild to severe pneumonia, bronchitis, pharyngitis, sinusitis, rarely death in healthy patients

Chronic infections have been associated with Atherosclerosis, Alzheimer’s, and asthma.

Can be a 1-4 week interval between initial symptoms and pulmonary involvement

Life Cycle

6-8 hours after the EB enters the cell it develops into a noninfectious RB within the cytoplasmic vacuole

There is about a 20 hour eclipse phase after entry when the EB develops into the RB.

The genome is transcribed into RNA, proteins are synthesized and the DNA is replicated.

18-24 hours after infection the RB divides by binary fission.

After the outer cell wall is made the RB develops into a new infectious EB.

Life Cycle

Epidemiology

2-5 million cases of pneumonia and 500,000 pneumonia-related hospitalizations occur in the US.

Transmission is person-to-person by respiratory secretions.

All ages are at risk, but school-age children are most common.

Infection doesn’t produce immunity.

Diagnosis

Difficult to grow

Diagnosis is made using assays that show an increase in IgG or IgM

Cultures are only positive about 50% of the time

The Complement Fixation (CF) test can be used to detect genus specific LPS

Microimmunofluorescence (MIF) uses an EB antigen

Treatment

Macrolides are the first-line treatment

Tetracyclines and Fluoroquinolones are also usedProlonged treatment is recommened (2-3 weeks)

In severe case, intravenous antibiotics are used

Prevention

There is no vaccine currently available

The best way to avoid this organism isGood Hygiene

Hand Washing

Avoid contact with infected people

Sources

http://www.cdc.gov/pneumonia/atypical/chlamydophila.html

Kauppinen M, Pekka S, Pneumonia due to Chlamydia pneumoniae: prevalence, clinical features, diagnosis, and treatment, Clinical Infectious Diseases, 1995;21:S244-52.

Guerra LG, Ho H, Verghese A, New pathogens in pneumonia, Medical Clinics of North America, 1994; 78:967-985.

Questions?