Pneumocystis carinii
Presented 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. Trophozoite
Filopodia 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 Reproduction
1. Trophozoite reproduction
Sexual Reproduction
1. 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
Malaise
Symptoms develop more slowly in those with AIDS and tend to be less severe
Diagnosis
Sputum 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
Bibliography
http://www.pathologyimagesinc.com/emhandbook/opport-infections-section/inf-agentspages/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-cariniipneumonia/overview.html
http://pathmicro.med.sc.edu/mycology/opportunistic.htm
http://www.healthscout.com/ency/68/558/main.html#PreventionofPneumocystisCarin
iiPneumonia(PCP)
http://dpd.cdc.gov/dpdx/html/Pneumocystis.htm
http://summaries.cochrane.org/CD005590/antibiotic-treatment-for-the-prevention-ofpneumocystis-pneumonia-pcp-in-non-hiv-immunocompromised-patients