Pneumocystis, an important opportunistic fungal pathogen that parasitizes in multiple mammalian lungs, may cause life-threatening Pneumocystis pneumonia (PCP) and even death among immunocompromised individuals. With the rapid development of high-throughput sequencing and multi-omics technologies, systematic comparative analyses of genome, transcriptome, and whole-genome sequencing results demonstrate that Pneumocystis is a type of obligate biotrophic fungi, and requires obtaining nutrition from hosts. In addition, sexual reproduction is an essential process for Pneumocystis survival, production and transmission, and asexual reproduction facilitates Pneumocystis survival, which provides new insights into understanding of the whole developmental process of Pneumocystis in the host lung and inter-host transmission of Pneumocystis. This review summarizes the advances in the reproduction mode of Pneumocystis and underlying mechanisms, which provides insights into prevention and treatment of PCP, notably for the prophylaxis against nosocomial transmission of PCP.
Humans ; Lung/microbiology* ; Pneumocystis/genetics* ; Pneumonia, Pneumocystis/microbiology*

Molecular karyotyping was applied to Pneumocystis carinii(Pc) from two strains of experimental rats, Sprague Dawley(SD) and Fisher(F), in Korea. Field inversion gel electrophoresis and contour clamped homogeneous electric field electrophoresis resolved 15 chromosomal bands from the Pc. The size of the bands was estimated 270kb to 684kb from SD rats, and 273kb to 713 kb from F rats. The bands of 283 kb from SD rats and of 273 kb from F rats stained more brightly suggesting duplicated bands. Total number of chromosomes was at least 16, and total genomic size was estimated 7 x 10(6) bp. All of the bands from F rats hybridized to the probe of repeated DNA sequences of Pc and the band of 448 kb size was proved to contain rDNA sequences, but Pc. chromosome bands from SD rats showed no reactions to the probes. The 2 different karyotypes of P. carinii from 2 strains of rats were maintained consistently for 2 years.
Electrophoresis- ; ; Korea- ; ; Nucleic-Acid-Hybridization ; Pneumocystis-carinii-isolation-and-purification ; Rats- ; *Karyotyping- ; ; *Pneumocystis-carinii-genetics ; *Rats,-Inbred-F344-microbiology ; *Rats,-Sprague-Dawley-microbiology

BACKGROUNDThe diagnosis of Pneumocystis pneumonia (PCP) in immunocompromised patients is still challenging today due to the absence of an in vitro culture system and the low diagnostic accuracy of microscopic examinations. Herein, we performed a meta-analysis to evaluate the accuracy of real-time polymerase chain reaction (PCR) in the diagnosis of PCP.

METHODSWe searched Web of Knowledge and Medline from 1990 to May 2010 for studies reporting diagnostic accuracy data regarding the use of real-time PCR in the diagnosis of PCP in immunocompromised patients.

RESULTSTen individual studies were included. Overall, the sensitivity of real-time PCR was 97% (95%CI: 93% - 99%); the specificity was 94% (95%CI: 90% - 96%). The area under the HSROC curve (95%CI) for real-time PCR was 0.99 (0.97 - 0.99). In a subgroup analysis regarding studies involving HIV patients among the study population, the sensitivity and specificity were 97% (95%CI: 93% - 99%) and 93% (95%CI: 89% - 96%), respectively. Regarding studies using Bronchoalveolar lavage (BAL) samples only: sensitivity = 98% (95%CI: 94% - 99%); specificity = 93% (95%CI: 89% - 96%), respectively. Regarding studies using microscopy as a reference standard: sensitivity = 97% (95%CI: 92% - 99%); specificity = 93% (95%CI: 88% - 96%). However, high between-study statistical heterogeneity was observed in all analyses.

CONCLUSIONSReal-time PCR has a good diagnostic accuracy and may provide a useful adjunctive tool for the diagnosis of PCP in immunocompromised patients. Further studies are needed in order to identify any differences in the diagnostic performance of real-time PCR in HIV and non-HIV immunocompromised patients.

Humans ; Immunocompromised Host ; Pneumonia, Pneumocystis ; diagnosis ; genetics ; Real-Time Polymerase Chain Reaction ; methods

BACKGROUNDPneumocystis jirovecii pneumonia (PCP) is one of the most common and fatal infections in non-AIDS immunocompromised patients, which is difficult to diagnose by traditional morphologic methods. This study evaluated polymerase chain reaction (PCR) assays of Pneumocystis jirovecii mitochondrial large subunits ribosomal RNA in sputum and bronchioalveolar lavage fluid (BALF) for diagnosing PCP.

METHODSSputum and BALF specimens from two groups were collected: one group (PCP group) included 20 patients definitely diagnosed of PCP by Gomori methenamine silver (GMS) stains of BALF; the other group (non-PCP group) included 40 patients. Each specimen was examined by GMS stains and PCR assays.

RESULTSGMS stains of BALF in PCP group were 100% positive (20/20), GMS stains of sputum in PCP group were 35% positive (7/20); GMS stains of BALF in non-PCP group were 100% negative (40/40), GMS stains of sputum in non-PCP group were 100% negative (40/40). PCR assays of BALF in PCP group were 100% positive (20/20), PCR assays of sputum in PCP group were 100% positive (20/20); PCR assays of BALF in non-PCP group were 100% negative (40/40), PCR assays of sputum in non-PCP group were 100% negative (40/40). Sensitivity and specificity of PCR assays of sputum and BALF were both 100%; positive and negative predictive values were also both 100%.

CONCLUSIONThe diagnostic value of PCR assays of Pneumocystis jirovecii mitochondrial large subunits ribosomal RNA on sputum and BALF for pneumocystis pneumonia are both high and equivalent.

Acquired Immunodeficiency Syndrome ; diagnosis ; genetics ; Bronchoalveolar Lavage Fluid ; chemistry ; Humans ; Pneumonia, Pneumocystis ; diagnosis ; genetics ; metabolism ; Polymerase Chain Reaction ; methods ; Sputum ; chemistry

A 50-year-old male visited the outpatient clinic and complained of fever, poor oral intake, and weight loss. A chest X-ray demonstrated streaky and fibrotic lesions in both lungs, and chest CT revealed multifocal peribronchial patchy ground-glass opacities with septated cystic lesions in both lungs. Cell counts in the bronchoalveolar lavage fluid revealed lymphocyte-dominant leukocytosis, and further analysis of lymphocyte subsets showed a predominance of cytotoxic T cells and few T helper cells. Video-assisted wedge resection of the left upper lobe was performed, and the histologic examination was indicative of a Pneumocystis jirovecii infection. Trimethoprim-sulfamethoxazole (TMP-SMX) was orally administered for 3 weeks; however, the patient complained of cough, and the pneumonia was aggravated in the follow-up chest X-ray and chest CT. Molecular studies demonstrated mutations at codons 55 and 57 of the dihydropteroate synthase (DHPS) gene, which is associated with the resistance to TMP-SMX. Clindamycin-primaquine was subsequently administered for 3 weeks replacing the TMP-SMX. A follow-up chest X-ray showed that the pneumonia was resolving, and the cough was also alleviated. A positive result of HIV immunoassay and elevated titer of HCV RNA indicated HIV infection as an underlying condition. This case highlights the importance of careful monitoring of patients with P. jirovecii pneumonia (PCP) during the course of treatment, and the molecular study of DHPS mutations. Additionally, altering the anti-PCP drug utilized as treatment must be considered when infection with drug-resistant P. jirovecii is suspected. To the best of our knowledge, this is the first case of TMP-SMX-resistant PCP described in Korea.
Anti-Bacterial Agents/*administration & dosage ; Drug Resistance, Bacterial ; Humans ; Lung/microbiology/radiography ; Male ; Middle Aged ; Pneumocystis jirovecii/*drug effects/genetics/isolation & purification/physiology ; Pneumonia/*drug therapy/immunology/microbiology/radiography ; Sulfamethoxazole/*administration & dosage ; Trimethoprim/*administration & dosage

Penicillium marneffei may cause life-threatening systemic fungal infection in immune-compromised patients and it is endemic in Southeast Asia. A 39-yr-old HIV-infected male, living in Laos, presented with fever, cough, and facial vesiculopapular lesions, which had been apparent for two weeks. CT scans showed bilateral micronodules on both lungs; Pneumocystis jirovecii was identified by bronchoscopic biopsy. Despite trimethoprim-sulfamethoxazole and anti-tuberculosis medications, the lung lesions progressed and the facial lesions revealed central umbilications. Biopsy of the skin lesions confirmed disseminated penicilliosis, with the culture showing P. marneffei hyphae and spores. The P. marneffei was identified by rRNA PCR. A review of the bronchoscopic biopsy indicated penicilliosis. The patient completely recovered after being prescribed amphotericin-B and receiving antiretroviral therapy. This is the first case of penicilliosis in a Korean HIV-infected patient. It is necessary to consider P. marneffei when immunocompromised patients, with a history of visits to endemic areas, reveal respiratory disease.
Adult ; Amphotericin B/therapeutic use ; Anti-HIV Agents/therapeutic use ; Antifungal Agents/therapeutic use ; Bronchoscopy ; Dermatomycoses/drug therapy/microbiology/pathology ; HIV Infections/*diagnosis/drug therapy ; Humans ; Immunocompromised Host ; Laos ; Lung Diseases/drug therapy/*microbiology ; Male ; Penicillium/genetics/*isolation & purification ; Pneumocystis jirovecii/isolation & purification ; Tomography, X-Ray Computed