Pneumocystis cariniiPresented by: Samantha Todd & Sandra Thorbus

Pneumocystis carinii vs. jirovecii

Both Pneumocystis carinii and Pneumocystis jirovecii (yee row vet zee) currently refer to the same organism. P. jirovecii is the organism isolated from humans, while P. carinii is found in rats.

Not a protozoan, but a fungus.

Hosts

Definitive Host: Humans, other mammals.

Intermediate Host: None

Prevalence

AIDS/HIV patients

Immunosuppressed individuals

Organ transplant recipients

Chemotherapy patients

Premature, malnourished infants

Most healthy children have been exposed by age 5

Geography

Worldwide

Three Morphological Forms

All three forms are found in the lungs

1. Precyst Oval shaped

Few filopodia

Cell wall thickening

Increase in number of nuclei from one to four

Three Morphological Forms

1. Cyst

-Mature cysts are spherical, have a thick chitinous membrane and eight intracystic bodies (young trophozoites)

Three Morphological Forms

3. TrophozoiteFilopodia form pockets in interstitial cells

Most abundant during infection (9:1)

Life Cycle

Life Cycle

Inhalation of infective respiratory droplets

Makes its way inside the respiratory tract, settles into alveolar spaces and replicates:

Asexual Reproduction1. Trophozoite reproduction

Sexual Reproduction1. Conjugation

2. Formation of Precyst

3. Formation of early cyst

4. Maturation and Excystment

Life cycle repeats

Transmission

Found in environment, lungs & upper respiratory tract of humans and animals

Spread by inhalation of infected respiratory droplets

Symptoms Causes Pneumocystis Pneumonia (PCP)

Fever

Cough

Shortness of breath

Cyanosis

Non-productive cough

Chest pain

MalaiseSymptoms develop more slowly in those with AIDS and tend to be less severe

DiagnosisSputum examination

Lung biopsy

Bronchial lavage

Blood gas test

Chest X-ray

Mortality rate is 100% in untreated patients.

Cysts of Pneumocystis carinii in smear from bronchoalveolar lavage.

Treatment

Trimethoprin-sulfamethoxazole (TMP/SMX, Bactrim)

Intravenous or oral administration

Alternative Treatments include:Pentamidine

Atovaquone

Combination of Trimethoprin and Dapsone

Prevention

Primary PCP prophylaxis (preventative antibiotic treatment before the onset of disease)

Reduces occurrence of PCP by 90%

Review

http://www.youtube.com/watch?v=cuZb539SaaY

Bibliographyhttp://www.pathologyimagesinc.com/emhandbook/opport-infections-section/inf-agents-pages/pneumocystis-carnii.html

http://microbewiki.kenyon.edu/index.php/Pneumocystis_carinii

http://www.nlm.nih.gov/medlineplus/ency/images/ency/fullsize/17278.jpg

http://health.nytimes.com/health/guides/disease/pneumocystis-carinii-pneumonia/overview.html

http://pathmicro.med.sc.edu/mycology/opportunistic.htm

http://www.healthscout.com/ency/68/558/main.html#PreventionofPneumocystisCariniiPneumonia(PCP)

http://dpd.cdc.gov/dpdx/html/Pneumocystis.htm

http://summaries.cochrane.org/CD005590/antibiotic-treatment-for-the-prevention-of-pneumocystis-pneumonia-pcp-in-non-hiv-immunocompromised-patients