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Published on: June 23, 2019
Pneumocystis jirovecii Colonization in Non-HIV-Infected Patients Based on Nested-PCR Detection in Bronchoalveolar
Hossein Khodadadi1, Hossein Mirhendi, Mehdi Mohebali
1Dept. of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.
Background:
Pneumocystis jirovecii causes Pneumocystis pneumonia (PCP) in immunocompromised patients with a high rate of morbidity and mortality. Colonization with this fungus may stimulate pulmonary inflammation or lead to PCP in susceptible patients. The epidemiology of this infection and routs of its transmission has poorly studied in Iran. We examined Pneumosystis colonization in patients with various lung underlying diseases.
Methods:
Bronchoalveolar lavage (BAL) fluids of 458 patients with different underlying diseases or pulmonary signs were collected between August 2010 and January 2012. Patients were divided into four groups: transplant recipients, malignant patients, immunosuppressive drug recipients and patients with other different lung diseases. A sensitive nested-PCR method targeted 18S ribosomal RNA gene was used for investigating P. jirovecii in the specimens.
Results:
P. jirovecii DNA was detected in 57 out of 458 (12.5%) BAL samples by nested-PCR. Colonization rate in malignant patients, transplant recipients, immunosuppressive therapy recipients and patients with other various lung diseases was 21.7%, 20.3%, 12.7% and 7.3%, respectively. The enzyme BanI cuts all PCR products producing fragments with the size of 228 and 104 base pair. This finding as well as sequencing of four random positive samples validated and reconfirmed the PCR results. P. jirovecii cysts were found in 5 out of 57 PCR positive samples.
Conclusion:
A significant number of patients with pulmonary diseases were colonized by P. jirovecii that can develop to PCP in these patients or they may transmit the fungus to other susceptible patients.
Insights
Pneumocystis jirovecii colonization is common in Iranian patients with lung diseases, detected via PCR in 12.5% of samples. This highlights potential risks for developing Pneumocystis pneumonia (PCP) or transmitting the fungus.
Area of Science:
- Medical Mycology
- Infectious Diseases
- Pulmonology
Background:
- Pneumocystis jirovecii causes severe Pneumocystis pneumonia (PCP) in immunocompromised individuals.
- Fungal colonization may precede PCP development or facilitate transmission.
- Epidemiology and transmission routes of P. jirovecii in Iran remain understudied.
Purpose of the Study:
- To investigate the prevalence of P. jirovecii colonization in patients with various underlying lung diseases in Iran.
- To assess colonization rates across different patient risk groups.
Main Methods:
- Bronchoalveolar lavage (BAL) samples were collected from 458 patients between August 2010 and January 2012.
- Patients were categorized into four groups: transplant recipients, malignancy patients, immunosuppressive drug recipients, and those with other lung diseases.
- A nested-PCR assay targeting the 18S ribosomal RNA gene was employed to detect P. jirovecii DNA.
Main Results:
- P. jirovecii DNA was identified in 12.5% (57/458) of BAL samples.
- Colonization rates varied by group: malignancy (21.7%), transplant recipients (20.3%), immunosuppressive therapy (12.7%), and other lung diseases (7.3%).
- PCR results were confirmed by restriction fragment length polymorphism (BanI enzyme) and sequencing; cysts were observed in 5 positive samples.
Conclusions:
- A significant proportion of patients with pulmonary diseases are colonized by P. jirovecii.
- Colonization represents a potential risk factor for PCP development and transmission to susceptible individuals.
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