Pneumocystis Jirovecii Colonization Research Articles

Clinical Characteristics and Prognosis of Patients With Severe Pneumonia With Pneumocystis jirovecii Colonization: A Multicenter, Retrospective Study

BackgroundFor decades, the incidence and clinical characteristics of Pneumocystis jirovecii (P. jirovecii) colonization in patients with severe pneumonia was remained unclear. Research questionWhat are the clinical features and outcomes associated with P. jirovecii colonization in individuals diagnosed with severe pneumonia? Study design and methodsIn this multicenter, retrospective, matched study, severe pneumonia patients who underwent bronchoalveolar lavage clinical metagenomics from 2019 to 2023 in the ICUs of 17 medical centers were enrolled. Patients were diagnosed based on clinical metagenomics, pulmonary CT scans, and clinical presentations. Clinical data were collected retrospectively, and according to propensity score matching and Cox multivariate regression analysis, the prognosis of patients with P. jirovecii colonization was compared to that of P. jirovecii-negative patients. Results40% of P. jirovecii positive patients are considered to have P. jirovecii colonization. P. jirovecii colonization group had a higher proportion of patients with immunosuppression and a lower lymphocyte count compared to P. jirovecii-negative group. More frequent detection of cytomegalovirus, Epstein–Barr virus, human herpesvirus-6B, human herpesvirus-7, and torque teno virus in the lungs was associated with P. jirovecii colonization than with P. jirovecii negativity. By constructing two cohorts through propensity score matching, we incorporated codetected microorganisms and clinical features into a Cox proportional hazards model and revealed that P. jirovecii colonization was an independent risk factor for mortality in severe pneumonia patients. According to sensitivity analyses, which included or excluded codetected microorganisms, as well as patients not receiving TMP-SMX treatment, similar conclusions were reached. InterpretationImmunosuppression and a reduced lymphocyte count were identified as risk factors for P. jirovecii colonization in non-PCP patients. More frequent detection of various viruses was observed in P. jirovecii colonization patients, and P. jirovecii colonization was associated with an increased 28-day mortality in patients with severe pneumonia.

Rapid Diagnosis of Pneumocystis jirovecii Pneumonia and Respiratory Tract Colonization by Next-Generation Sequencing

ObjectivesTo describe the epidemiology of Pneumocystis jirovecii pneumonia and colonization diagnosed by next-generation sequencing (NGS) and explore the usefulness of the number of P. jirovecii sequence reads for the diagnosis of P. jirovecii pneumonia.MethodsWe examined the NGS results for P. jirovecii in respiratory samples collected from patients and analysed their clinical, radiological and microbiological characteristics.ResultsAmong 285 respiratory samples collected over a 12-month period (January to December 2022), P. jirovecii sequences were detected in 56 samples from 53 patients. Fifty (94.3%) of the 53 patients were HIV-negative. Following our case definitions, 37 (69.8%) and 16 (30.2%) of the 53 patients had P. jirovecii infection and colonization respectively. P. jirovecii infection was associated with presence of underlying disease with immunosuppression (94.6% vs 18.8%, P < 0.05), positive serum 1,3-β-D-glucan (41.2% vs 0%, P < 0.01) and higher number of P. jirovecii sequence reads (P < 0.005). In contrast, P. jirovecii colonization was associated with the male sex (93.8% vs 54.1%, P < 0.01), another definitive infectious disease diagnosis of the respiratory tract (43.8% vs 2.7%, P < 0.001) and higher survival (100% vs 67.6%, P < 0.01). Although P. jirovecii pneumonia was associated with higher number of P. jirovecii reads in respiratory samples, only a sensitivity of 82.14% and a specificity of 68.75% could be achieved.ConclusionDetection of P. jirovecii sequences in respiratory samples has to be interpreted discreetly. A combination of clinical, radiological and laboratory findings is still the most crucial in determining whether a particular case is genuine P. jirovecii pneumonia.

Clinical Performance of BALF Droplet Digital PCR for Differential Diagnosis of Pneumocystis jirovecii Pneumonia and Pneumocystis jirovecii Colonization

BackgroundAccurate differentiation between Pneumocystis jirovecii (Pj) infection and colonization is crucial for effective treatment. MethodsFrom September 2016 to June 2022, 89 immunocompromised patients with unexplained lung infiltrates and clinical suspicion of Pj pneumonia were enrolled at Peking University People's Hospital. Bronchoalveolar lavage fluid (BALF) of these patients were detected by quantitative PCR (qPCR) and droplet digital PCR (ddPCR). ResultsThe performance of ddPCR was superior to qPCR in detecting Pj infection. Area under the curve was 0.97 (95%CI: 0.94–1) for ddPCR of the BALF in all patients. The optimal threshold value for discriminating Pj infection from colonization was 13.98 copies/test, with a sensitivity of 97.96%, specificity of 85.71%. No obvious correlation between ddPCR copy number and disease severity was observed. ConclusionBALF ddPCR exhibits robust potential in detecting Pj and effectively discriminating colonization and infection.

Prevalence of Pneumocystis jirovecii Colonization in Non-Critical Immunocompetent COVID-19 Patients: A Single-Center Prospective Study (JiroCOVID Study).

Pneumocystis jirovecii pneumonia (PJP) is an invasive fungal infection (IFI) that occurs mainly in immunocompromised hosts. After observing a high prevalence of PJP as a complication of COVID-19 in immunocompetent patients, we conducted a study to evaluate the prevalence of P. jirovecii colonization with PCR on oral washing samples (OWS) among non-immunocompromised and non-critical patients admitted with COVID-19 pneumonia at our university hospital. All patients over 18 years of age admitted to the Infectious Diseases Unit for SARS-CoV-2 pneumonia between July 2021 and December 2022 were included. Patients undergoing invasive mechanical ventilation or ECMO, those with risk factors for developing PJP, and those receiving prophylaxis for P. jirovecii were excluded. Samples were collected by gargling with 10 mL of 0.9% NaCl on day 14 of the hospital stay or at discharge. Of 290 screened patients, 59 (20%) met the inclusion criteria and were enrolled. Only 1 of 59 patients (1.7%) tested positive for P. jirovecii detection with PCR, and the same patient was the only one to develop PJP in the follow-up period. Our results are in line with the previous findings of other studies that confirmed a very low prevalence of P. jirovecii colonization on OWS in the immunocompetent population. Despite the limitations of the study, the fact that the only patient who tested positive for P. jirovecii was the only one in our cohort to develop PJP leads us to reflect on the role of this non-invasive sample in predicting the risk of PJP in patients with COVID-19.

Pneumocystis jirovecii Colonization in Mexican Patients with Chronic Obstructive Pulmonary Disease.

The prevalence of colonization by Pneumocystis jirovecii (P. jirovecii) has not been studied in Mexico. We aimed to determine the prevalence of colonization by P. jirovecii using molecular detection in a population of Mexican patients with chronic obstructive pulmonary disease (COPD) and describe their clinical and sociodemographic profiles. We enrolled patients discharged from our hospital diagnosed with COPD and without pneumonia (n = 15). The primary outcome of this study was P. jirovecii colonization at the time of discharge, as detected by nested polymerase chain reaction (PCR) of oropharyngeal wash samples. The calculated prevalence of colonization for our study group was 26.66%. There were no statistically significant differences between COPD patients with and without colonization in our groups. Colonization of P. jirovecii in patients with COPD is frequent in the Mexican population; the clinical significance, if any, remains to be determined. Oropharyngeal wash and nested PCR are excellent cost-effective options to simplify sample collection and detection in developing countries and can be used for further studies.

Pneumocystis jirovecii colonization in bronchoalveolar lavage among naïve non-small cell lung cancer from tertiary respiratory hospital in Jakarta, Indonesia.

Pneumocystis jirovecii pneumonia (PJP) is a lung mycosis commonly found in immunocompromised patients (e.g., HIV patients); however, its role in solid cancer remains unclear. This study aims to identify Pneumocystis jirovecii colonization among naïve non-small-cell lung cancer (NSCLC) through bronchoalveolar lavage (BAL) and explore its correlation with clinical parameters. This cross-sectional study recruited newly diagnosed naïve NSCLC patients who had not been given systemic treatments. We tested BAL from patients for P. jirovecii colonization with nested PCR targeting the mtLSU rRNA gene. Demographic and clinical characteristics were obtained from medical records, and the correlation between P. jirovecii colonization and clinicopathological data were analyzed. Kaplan-Meier analyses were done to evaluate survival. Among 56 newly diagnosed, naïve NSCLC patients enrolled, the prevalence of P. jirovecii colonization was 17.9% (10 subjects). There was no statistically significant difference in demographic and clinical characteristics between the P. jirovecii colonization group versus no colonization (p value &gt; 0.05). The overall survival duration for both groups demonstrated no significant difference. This study demonstrated a relatively high prevalence of P. jirovecii colonization among BAL samples of naïve Indonesian NSCLC patients. Further study is needed to delineate its implications for the potential transmission source, lung cancer pathogenesis, and prognosis.

Is It Possible to Differentiate Pneumocystis jirovecii Pneumonia and Colonization in the Immunocompromised Patients with Pneumonia?

Respiratory sample staining is a standard tool used to diagnose Pneumocystis jirovecii pneumonia (PjP). Although molecular tests are more sensitive, their interpretation can be difficult due to the potential of colonization. We aimed to validate a Pneumocystis jirovecii (Pj) real-time PCR (qPCR) assay in bronchoscopic bronchoalveolar lavage (BAL) and oropharyngeal washes (OW). We included 158 immunosuppressed patients with pneumonia, 35 lung cancer patients who underwent BAL, and 20 healthy individuals. We used a SYBR green qPCR assay to look for a 103 bp fragment of the Pj mtLSU rRNA gene in BAL and OW. We calculated the qPCR cut-off as well as the analytical and diagnostic characteristics. The qPCR was positive in 67.8% of BAL samples from the immunocompromised patients. The established cut-off for discriminating between disease and colonization was Ct 24.53 for BAL samples. In the immunosuppressed group, qPCR detected all 25 microscopy-positive PjP cases, plus three additional cases. Pj colonization in the immunocompromised group was 66.2%, while in the cancer group, colonization rates were 48%. qPCR was ineffective at diagnosing PjP in the OW samples. This new qPCR allowed for reliable diagnosis of PjP, and differentiation between PjP disease and colonization in BAL of immunocompromised patients with pneumonia.

Quantitative PCR to Discriminate Between Pneumocystis Pneumonia and Colonization in HIV and Non-HIV Immunocompromised Patients.

Pneumocystis pneumonia (PCP) is an opportunistic infection that commonly occurs in immunocompromised individuals. A definite diagnosis of PCP can be made only when the organism is identified in a respiratory specimen. It remains unclear whether qPCR can differentiate patients with PCP from those with Pneumocystis jirovecii colonization. In this study, we retrospectively collected data from HIV and non-HIV patients during 2013–2019. A diagnosis of definite, probable PCP, or PCP excluded was made based on clinical criteria, radiological reports, and three standard laboratory staining methods with blinding to qPCR data. Data from qPCR that was performed to determine the fungal burden (DNA copies/μl) in the BAL specimens of 69 HIV and 286 non-HIV patients were then obtained and reviewed. Receiver Operating Characteristic (ROC) curve analysis was performed to determine the upper and lower cut-off values for PCP diagnosis in HIV and non-HIV groups. In the non-HIV group, the lower cut-off value of 1,480 DNA copies/μl yielded a sensitivity of 100% (95% confidence interval [CI], 91.0–100), specificity of 72.9% (95% CI, 64.0–80.7), a positive predictive value (PPV) of 54.9% (95% CI, 47.6–62.1), and a negative predictive value (NPV) of 100% with Youden index of 0.73 for PCP diagnosis. In this group, the upper cut-off value of 9,655 DNA copies/μl showed the sensitivity of 100% (95% CI, 91.0–100) and specificity of 95.8% (95% CI, 90.4–98.6) with PPV of 88.6% (95% CI, 76.8–94.8) and a NPV of 100% with Youden index of 0.96 for PCP diagnosis. Regarding the HIV group, the lower cut-off value of 1,480 DNA copies/μl showed the sensitivity of 100% (95% CI, 92.5–100%) and specificity of 91.7% (95% CI, 61.5–99.8) with PPV of 97.9% (95% CI, 87.8–99.7) and a NPV of 100% with Youden index of 0.92 for PCP diagnosis. The sensitivity and specificity of the upper cut-off value of 12,718 DNA copies/μl in this group were 97.9% (95%CI, 88.7–100) and 100% (95%CI, 73.5–100), respectively. The values above the upper cut-off point had a PPV of 100% (95% CI, N/A) and a NPV of 92.3% (95% CI, 63.3–98.8) with Youden index of 0.98 for PCP diagnosis in the HIV group.

Pneumocystis jirovecii Colonization in Preterm Newborns With Respiratory Distress Syndrome.

We describe the prevalence of Pneumocystis jirovecii in mother-infant pairs of very low birth weight newborns <32 weeks gestation. Molecular and microscopic methods were used for detection of P. jirovecii in patients’ specimens. Pneumocystis DNA was detected in 8 nasopharyngeal aspirates (14%) of 56 newborns and in 7 oral washes (21%) of 34 mothers. Pneumocystis detection immediately after birth suggests the possibility of its transplacental transmission. Compared to noncolonized infants, more frequent occurrence of bronchopulmonary dysplasia was seen in colonized infants (P = .02), suggesting a potential clinical importance of this pathogen in abnormal lung development.

Investigation of Pneumocystis jirovecii Infection and Colonization in Immunocompromised Patients with Pneumonia

Pneumocystis jirovecii is an atypical fungus that causes P.jirovecii pneumonia (PCP) in immunocompromised patients. Currently, while the incidence of AIDS-related PCP is decreasing, PCP has become more common in HIV-negative immunosuppressive patients as a result of increased diseases requiring immunosuppressive therapy. In this study, it was aimed to investigate PCP and colonizations by microscopy, polymerase chain reaction (PCR) and Krebs von den Lungen-6 (KL-6) tests in symptomatic immunosuppressive inpatients with the sign of radiologically atypical pneumonia in Mersin University Hospital. A total of 96 patients, between August 2016 and February 2018 were included in the study. Seventy two (75%) of the 96 patients were under immunosuppressive therapy. P.jirovecii was investigated in the respiratory tract samples [sputum (n= 88), tracheal aspirate (n= 6) and bronchoalveolar lavage (n= 2)] by mtLSUrRNA nested PCR and microscopic staining methods [immunofluorescence assay (IFA), Toluidine Blue O (TBO)], and KL-6 levels were tested in serum samples. P.jirovecii was detected in 16 (16.7%) samples by PCR, in five (5.2%) samples by IFA, in three (3.1%) samples by TBO stain method. When IFA was taken as a reference test, sensitivity and specificity of TBO and PCR were calculated as 60% and 100%; 100% and 87.9%, respectively. In P.jirovecii PCR positive patients, the distribution of underlying diseases; cancer (n= 6), hematological malignancy (n= 3), HIV/AIDS (n= 3), COPD (n= 2), and interstitial lung disease (n= 2) were found as 11 (68.75%) of the 16 positive patients, received immunosuppressive therapy (HIV positive non-Hodgkin lymphoma); of the 3 (18.75%) patients of were immunocompetent, and only 2 (12.5%) were HIV/AIDS. Five of the 16 PCR positive the patients that have positive microscopic examination were definited PCP [HIV/AIDS (n= 3), lung cancer (n= 1), interstitial lung disease (n= 1)]; three patients were PCR positive and microscopy negative probable PCP [multiple myeloma (n= 1), interstitial lung disease (n= 1), cholangiocellular carcinoma (n= 1)] and eight other patients were identified as colonized. In the study, when the frequency of the detection of P.jirovecii was evaluated according to the underlying diseases, it was found statistically significantly higher only in HIV/AIDS patients (p= 0.012). When KL-6 was evaluated among the patients defined as PCP/possible PCP and colonization, sensitivity and specificity were determined as 62.5% and 75%, respectively. As a result, nested PCR method was found as sensitive and successful for the detection of P.jirovecii from sputum samples. KL-6 test was not found sufficient for the differentiation of colonization and the infection in PCR positive patients. The results obtained in the study showed that PCP should be on the differential diagnosis list according to the immune status and the clinical features of the inpatients. More researchs are required with more patients to achieve for detailed reliable results in these groups. In addition, molecular epidemiological studies related to genotyping and resistance against anti-PCP drugs are needed to understand P.jirovecii infections in our region and country.

Pneumocystis jirovecii Pneumonia and Human Immunodeficiency Virus Co-Infection in Western Iran

The human immunodeficiency virus (HIV) is one of the greatest health challenges facing worldwide. The virus suppresses the immune system of the patient. The purpose of this study was to describe the epidemiology of Pneumocystis jirovecii colonization, rarely found in normal people, in patients with stage 4 HIV infection in Kermanshah, Iran, from Mar 1995 to Feb 2016. In this retrospective study, we surveyed medical records of stage 4 HIV-positive patients with Pneumocystis admitted to Behavioral Counseling Center of Kermanshah. Several parameters were analyzed including demographic characteristics, body mass index (BMI), treatment regimen, diagnostic methods, presenting signs and symptoms, presence of co-pathogens (bacteria, viruses, or fungi), and nadir of CD4 T-cell count before and after treatment. During the study period, 114 HIV-positive patients were analyzed, of whom 93 were male and 21 were female, respectively. Of 114 cases, 26 (22.8%) patients had Pneumocystis. All 26 colonized patients had CD4 cell counts below 200 cells/mm3 (range 9-186). The median CD4 count increased from 91 cells/mm3 pre-trimethoprim/sulfamethoxazole (TMP/SMX) to an estimated 263 cells/mm3 after starting (TMP/SMX). BMI was normal in the majority of the patients (85%) and coughs, sputum, and chest pain (19; 73%) followed by dyspnea, weakness, and lethargy (7; 27%) were the most common presentations of fungal pneumonia. HIV/AIDS-infected patients are an environmental reservoir of P. jirovecii infection that might transmit the infection from one person to another via the airborne route. In addition, rapid identification of such individuals may reduce the morbidity and mortality rate of this disease.

Pneumocystis jirovecii colonization and its association with pulmonary diseases: a multicenter study based on a modified loop-mediated isothermal amplification assay

BackgroundPneumocystis jirovecii (P. jirovecii) is an opportunistic fungal pathogen and the role of its colonization in pulmonary diseases has become a popular focus in recent years. The aim of this study was to develop a modified loop-mediated isothermal amplification (LAMP) assay for detection of Pneumocystis jirovecii (P. jirovecii) DNA amongst non-HIV patients with various pulmonary diseases and use it to examine the prevalence and assess the association of P. jirovecii colonization with clinical characteristics of these diseases.MethodsWe modified the previously reported LAMP assay for P. jirovecii by adding real-time detection. This method was used to detect P. jirovecii colonization in pulmonary samples collected from 403 non-HIV patients with various pulmonary diseases enrolled from 5 hospitals in China. We determined the prevalence of P. jirovecii colonization in 7 types of pulmonary diseases and assessed the association of P. jirovecii colonization with clinical characteristics of these diseases.ResultsThe modified LAMP assay showed no cross-reactivity with other common pulmonary microbes and was 1000 times more sensitive than that of conventional PCR. Using the modified LAMP assay, we detected P. jirovecii colonization in 281 (69.7%) of the 403 patients enrolled. P. jirovecii colonization was more common in interstitial lung diseases than in chronic obstructive pulmonary disease (COPD) (84.6% vs 64.5%, P < 0.05). Patients with acute exacerbation of COPD had a higher prevalence of P. jirovecii colonization compared to patients with stabilized COPD (67.4% vs 43.3%, P < 0.05). P. jirovecii colonization was associated with decreased pulmonary function, increased levels of 1,3-β-D-glucan and C-reactive protein, and decreased levels of CD4+ T-cell counts (P < 0.05 for each). Approximately 70% of P. jirovecii colonized patients had confections with other fungi or bacteria.ConclusionsWe developed a modified LAMP assay for detecting P. jirovecii. Our multi-center study of 403 patients supports that P. jirovecii colonization is a risk factor for the development of pulmonary diseases and highlights the need to further study the pathogenesis and transmission of P. jirovecii colonization in pulmonary diseases.

Pneumocystis jirovecii in Spanish Patients With Heart Failure.

Objective: Pneumocystis colonization is frequent in patients with chronic obstructive pulmonary disease (COPD) producing local and systemic inflammation. Heart failure is also a common comorbidity among patients with COPD. Heart failure is a chronic, frequent, and disabling condition with high morbidity and mortality, but with a modifiable course where endothelial dysfunction and pulmonary arterial hypertension have great importance. Animal models have shown that Pneumocystis infection can cause relevant functionally changes in vascular responses in the lung, promoting the development of pulmonary hypertension. Pneumocystis colonization could be a hidden cause of worsening heart failure through it capacity to induce inflammatory response with subsequent endothelial dysfunction and pulmonary hypertension. The aim of the present study was to investigate the prevalence of Pneumocystis jirovecii colonization in heart failure patients and its possible association with reduced or preserved ejection fraction.Methods: A cross-sectional study was carried out including 36 heart failure patients and 36 control cases. Identification of P. jirovecii colonization was performed by means of molecular techniques in oropharyngeal washing.Results: Pneumocystis-DNA was identified in oropharyngeal washing in 1 (2.7%) of 36 heart failure patients and in 3 (8.3%) of 36 controls.Conclusions: Pneumocystis colonization does not seem to have a role in the pathophysiology of heart failure.

A multi-centered study of Pneumocystis jirovecii colonization in patients with respiratory disorders: Is there a colonization trend in the elderly?

Background and Purpose: Pneumocystis jirovecii colonization plays a key role in the progression of pulmonary infection. However, there are limited data regarding the colonization of these fungi in the patients residing in different regions of Iran. Regarding this, the present study was conducted to evaluate the prevalence of P. jirovecii colonization in non-HIV-infected patients with respiratory failure introduced by physicians using nested polymerase chain reaction (PCR).Materials and Methods:This study was conducted on 136 samples obtained from 136 patients with respiratory disorders referring to different hospitals in the capital and north of Iran during 2013-2015. The samples were collected using bronchoalveolar lavage (BAL; n=121) and sputum induction (n=15). Nested PCR method targeting mtLSU rRNA gene was used for the detection of P. jirovecii DNA in the specimens.Results:The nested PCR analysis resulted in the detection of P. jirovecii DNA in 32 (23.5%) patients. The mean age of the participants was 49.04±11.94 years (age range: 14-90 years). The results revealed no correlation between Pneumocystis colonization and gender. The studied patients were divided into two groups of immunocompromised and immunocompetent patients. In the regard, 25.4% of the patients with detectable P. jirovecii DNA were immunocompromised and had cancer, organ transplantation, asthma, sarcoidosis, dermatomyositis, chronic obstructive pulmonary disease, bronchiectasis, and pulmonary vasculitis. On the other hand, Pneumocystis DNA was detected in 21.8% of the immunocompetent patients. Frequencies of P. jirovecii DNA detection in the patients with tuberculosis, hydatid cyst, and unknown underlying diseases were obtained as 20.8%, 25%, and 22%, respectively. The prevalence of Pneumocystis colonization varied based on age. In this regard, P. jirovecii colonization was more prevalent in patients aged above 70 years.Conclusion:As the findings indicated, non-HIV-infected patients, especially the elderly, had a high prevalence of P. jirovecii colonization. Therefore, these patients are probably a potential source of infection for others. Regarding this, it is of paramount importance to adopt monitoring and prophylactic measures to reduce this infection.

New DNA Extraction Method for the Detection of Pneumocystis in Lung Tissue Samples of Colonized Individuals

Background: Pneumocystis jirovecii colonization in patients is associated with a low organism burden, which supports the need to use highly sensitive molecular techniques, such as nested-PCR to determine the presence of the organism. However, few studies have considered the effect of nucleic acid extraction methods on the detection of P. jirovecii. Here, we evaluate how pre-treatment affects microbial detection. Methods: Lung tissue samples from fifteen autopsied infants were processed using two different DNA extraction protocols: 1) the QIAamp DNA Mini kit (Qiagen) (method A) and the QIAamp DNA Mini kit (Qiagen) with additional steps including a pre-treatment, bead-beating and phenol-chloroform steps (method B). Detection of P. jirovecii was performed using the conventional nested-PCR in lung tissue samples. In addition, we estimated the bacterial, fungal and human DNA using qPCR method. Results: Higher DNA yields was obtained with DNA extraction method B compared to method A. P. jirovecii was detected in 10 out of 15 lung tissue samples for both methods at the first or second round of PCR. However, P. jirovecii was detected in 9 out of 10 at the first round with the DNA extraction method B, rather than those processed with DNA extraction method A that were detected in 5 out of 10. Moreover, the faint PCR band intensity observed in 2 out of 6 samples processed with DNA extraction method A was increased with method B. We also observed that DNA extraction method B increased significantly the bacterial and fungal DNA, but not the human DNA, compared to method A. Conclusions: Our findings show that the additional steps (i.e. pre-treatment, bead-beating and Phenol: Chloroform: Isoamyl alcohol steps) supplemented to the QIAamp DNA Mini kit (Qiagen) improves the detection of P. jirovecii in lung tissue samples.

Differentiation between pneumocystis jirovecii pneumonia and colonization in immunocompromised patients

BackgroundThe diagnosis of Pneumocystis jirovecii pneumonia (PJP) is mainly based on microscopic detection of P. jirovecii in the respiratory samples. Quantitative PCR (qPCR) can detect low levels of P. jirovecii DNA but cannot differentiate between infection and colonization. Therefore a new and more accurate assay have to be used. 1,3 BD-glucan (BD-glucan) with a threshold value of 100 pg/ml can differentiate P. jirovecii infection from colonization.AimThe aim of this study is to evaluate the diagnostic accuracy of qPCR and BD-glucan assays in differentiating pneumocystis infection from colonization in immunocompromised patients with help of radiological pulmonary infiltrates.Patients and methodsThis study consisted of 75 immunocompromised patients (37 renal transplanted patients and 38 HIV patients) who were admitted for radiological pulmonary infiltrates and who presented a clinical picture suspecting PJP. They were investigated using microscopic staining of their respiratory samples (induced sputum or bronchoalveolar lavage).By applying both qPCR and serum BD-glucan assays we can differentiate between P. jirovecii infection from colonization.ResultsIn this study, the first group of 25 patients were diagnosed as definite PJP, the second group of 20 patients were diagnosed as having pneumonia with P. jirovecii colonization, and a third group of 30 patients were diagnosed as having pneumonia without colonization. The number of copies of fungal DNA detected by qPCR were significantly higher in a definite PJP than in those with pneumonia accompanied with P. jirovecii colonization. Also BD-glucan assays were significantly higher in definite PJP by applying a threshold value of 100 pg/ml. The sensitivity and specificity of qPCR for differentiation of PJP infection from colonization were 100 and 64%, respectively, whereas the sensitivity and specificity of BD-glucan were 100 and 96%, respectively.ConclusionBoth BD-glucan and qPCR assays had high diagnostic values in differentiating definite PJP from P. jirovecii colonization, and by applying qPCR with two cutoff values combined with serum BD-glucan using a threshold value of 100 pg/ml.

Epidemiological characteristics of Pneumocystis jirovecii infection and colonization in non-AIDS patients

Objective: To analyze the epidemiological characteristics of Pneumocystis jirovecii infection and colonization in non-AIDS patients. Methods: From January 2010 to December 2017, bronchoalveolar lavage fluid (BALF) was detected by Grocott's methenamine silver (GMS) staining and real-time fluorescence quantitative PCR (qPCR) in non-AIDS patients with bronchoscopic alveolar lavage at Peking University First Hospital. At the same time, Pneumocystis jirovecii was detected in the environment of the hospital. Results: Within 8 years, Pneumocystis jirovecii were detected in BALF of a total of 1 407 non-AIDS patients. GMS staining was performed in all these 1 407 cases, of which 114 (8.10%) cases were with Pneumocystis jirovecii infection and 3 (0.21%) cases with colonization. There were totally 946 non-AIDS immunocompromised patients, of which 113 (11.95%) cases were infected and 2 (0.21%) cases with colonization; there were 461 non-AIDS immunocompetent patients, of which only 1 (0.22%) case was infected and 1 (0.22%) case with colonization. GMS staining and qPCR were both performed in 196 cases, of which 36 (18.37%) cases were infected and 33 (16.84%) cases with colonization. There were totally 175 non-AIDS immunocompromised patients, of which 36 (20.57%) cases were infected and 30 (17.14%) cases with colonization; there were 21 non-AIDS immunocompetent patients, of which no one was infected and 3 (14.29%) cases with colonization. By means of GMS staining and qPCR, no Pneumocystis jiroveci were detected in the environment of Peking University First Hospital. Conclusions:Pneumocystis pneumonia is rare in immunocompetent patients, but not in non-AIDS immunocompromised patients. And colonization is rare in both of them. There may be no Pneumocystis jiroveci in the environment.

The investigation of Pneumocystis jirovecii colonization in adult individuals of Turkish population

The investigation of Pneumocystis jirovecii colonization in adult individuals of Turkish population

A study on the colonization of Pneumocystis jirovecii among outpatients during cancer chemotherapy and among healthy smokers.

Pneumocystis Jirovecii (PJ) is regarded as an agent of fungal infection and in cases of pneumocystis pneumonia (PCP) in immune-compromised patients including cancer patients. It is not clear what kinds of cancer, treatments, and environment need prophylaxis for PCP. In this study, we have analyzed the detectability of PJ DNA from sputum, and discussed prophylaxis and risk factors regarding PCP. A total of forty-nine materials (twenty-four from outpatients during cancer chemotherapies and twenty-five from healthy control subjects) was collected. Their PJ DNAs were amplified using nested PCR with specific primers of the PJ gene (the mitochondrial small subunit rRNA gene). PJ DNA was detectable in 46% of specimens (sputum) from cancer patients during chemotherapies, and incidences of not significantly different among types of cancer and chemotherapy regimens. Prophylactic use of Sulfamethoxazole/Trimetoprim (ST) reduced the detection of PJ DNA. Detection of PJ DNA is not high among healthy non-smokers (20%) and high among healthy smokers (47%). Prophylactic use of ST may be necessary for cancer patients during chemotherapies. Also, smoking may be associated with PJ colonization in the airway and air vesicles, and may increase the mortality rate for PCP. All patients undergoing cancer chemotherapies should cease smoking.

Early Acquisition of Pneumocystis jirovecii Colonization and Potential Association With Respiratory Distress Syndrome in Preterm Newborn Infants.

Pneumocystis pneumonia is a well-recognized lung disease of premature and malnourished babies. Even though serologic studies have shown that children are exposed to Pneumocystis jirovecii early in life, the epidemiology of human P. jirovecii infection and the host-microorganism relationship in infancy remain poorly understood. The aim of the present study was to investigate the prevalence of P. jirovecii colonization in preterm infants and its possible association with medical complications. A prospective observational study of preterm infants (birth weight <1500 g and/or gestational age <32 weeks) was carried out. Identification of P. jirovecii colonization was performed by means of molecular techniques in nasal aspirated samples at birth. A total of 128 preterm infants were included during the study period. Pneumocystis DNA was identified in 25.7% (95% confidence interval [CI], 17.8%-33.7%) of newborns studied. A significant increase of respiratory distress syndrome in colonized group, even after adjusting for confounding factors (odds ratio, 2.7 [95% CI, 1.0-7.5]; P = .04), was observed. No differences were observed in other medical conditions between the 2 groups. Pneumocystis jirovecii colonization is frequent in preterm births and could be a risk factor to develop respiratory distress syndrome among preterm infants.