Pulmonary Fungal Pathogens Research Articles

Analytical and clinical validation of multiplex droplet digital PCR assay for detecting pathogenic fungal infection in lungs

ABSTRACT Pulmonary invasive fungal infection in immunocompromised hosts is difficult to diagnose, and current tools for diagnosis or monitoring of response to antifungal treatments have inherent limitations. Droplet digital PCR (ddPCR) has emerged as a promising tool for pulmonary pathogen detection with high sensitivity. This study presents a novel ddPCR panel for rapid and sensitive identification of pulmonary fungal pathogens. First, a ddPCR method for detecting three fungal genera, including Pneumocystis, Aspergillus, and Cryptococcus, was established and evaluated. Then, the clinical validation performance of ddPCR was compared with that of qPCR using 170 specimens, and the 6 specimens with inconsistent results were further verified by metagenomics next-generation sequencing, which yielded results consistent with the ddPCR findings. Finally, the area under the ROC curve (AUC) was used to evaluate the efficiency of ddPCR. While the qPCR identified 16 (9.41%) cases of Aspergillus and 6 (3.53%) cases of Pneumocystis, ddPCR detected 20 (11.76%) Aspergillus cases and 8 (4.71%) Pneumocystis cases. The AUC for Aspergillus, Cryptococcus, and Pneumocystis was 0.974, 0.998, and 0.975, respectively. These findings demonstrated that the ddPCR assay is a highly sensitive method for identifying pathogens responsible for invasive fungal pulmonary infections, and is a promising tool for early diagnosis.

Comparison between HRM and Culture to Detect Most Common Pathogenic Fungi in Patients with Respiratory Diseases

Back Ground: The respiratory fungal infection has increased globally, becoming an important cause of morbidity and mortality, especially in immunocompromised patients, such as patients with Diabetic Mellitus (DM), cancer patients. The most common fungal related result from species that belong genera include: Candida spp., Aspergillus spp., Cryptococcus spp., and Mucor spp. Clinically respiratory fungal infection was nonspecific and indistinguishable from other infection, making early diagnosis and correct treatment essential and urgent. Laboratory diagnosis involves traditional diagnostic methods, such as direct and culture, which are still considered the gold standards but have low sensitivity, time consuming and is sometimes only confirmed in late stages. Molecular method as High Resolution Melting (HRM PCR) for Broncho alveolar lavage (BAL) to detect and identify of most clinically important fungal pathogens with high sensitivity and specificity are showing the potential assay to replace traditional diagnostic assay. Material and method: One hundred seventeen (BAL) lavage sample from patients with respiratory disease were submitted to conventional methods (culture) and molecular method (HRM PCR) for detection of most common infection of fungal respiratory tract. Results: Out of the 117 BAL samples collected in the study, in the age group (61–70) years recorded the highest pulmonary diseases, 34 (29.0%), whereas the age group (31–40) recorded the lowest prevalence of pulmonary diseases was 3 (2.5%). There was significant association between age and prevalence of pulmonary diseases (P = 0.055). Males had relatively higher prevalence of fungal isolates, 18 (60%) than females' counterpart, 12(40%) it was no significant association was seen between sex and the prevalence of fungal pathogens (P = 0.55). Based on the risk factors considered in the study, participants with smoking, cancer and diabetic mellitus had a significantly higher risk of pulmonary fungal pathogens. By culture method, the following Fungi were identified: Candida spp. Twenty (66.6%), five (16.6%) samples were Aspergillus spp., Cryptococcus spp. 4 (13.3%), and only one (3.3%) sample as Mucor spp. while by molecular method (Multiplex HRM PCR) the result of 29 (24.7%) samples which were culture and conventional PCR positive detected, 15 (51.7%) were positive including: 8 (53.3%) Candida spp., 4(26.6%) Aspergillus spp., 2(13.3%) Cryptococcus neoformans, and only one (4.3%) Mucor spp. Conclusion: Referring to fungal species which was detected by culture method and HRM using specificspecies primers include: Candida pp. Aspergillus spp., Cryptococcus spp. and Mucor spp. It was seen that, Candida spp. and Apergillus spp. Had the highest positive percentages among other species. Multiplex HRM PCR is a faster analysis with high sensitive 100% to detect the most common fungal pathogens. Despite a cost-effective, make it an ideal tool for fast screening in patients at risk of fungal respiratory infection.

Status of pulmonary fungal pathogens among individuals with clinical features of pulmonary tuberculosis at Mbarara University Teaching Hospital in Southwestern Uganda.

Background:Pulmonary mycoses are important diseases of the respiratory tract caused by pulmonary fungal pathogens. These pathogens are responsible for significant morbidity and mortality rates worldwide; however, less attention has been paid to them. In this study we determined the prevalence of pulmonary fungal pathogens among individuals with clinical features of pulmonary tuberculosis at Mbarara Regional Referral Hospital.Method:This was a hospital based cross sectional survey. Sputum samples were collected from each study participant. For each sample, the following tests were performed: Sabouraud dextrose agar for fungal culture, GeneXpert for Mycobacteria tuberculosis (MTB) and potassium hydroxide for fungal screening. Filamentous fungal growth and yeasts were further examined with lactophenol cotton blue staining and germ tube respectively.Results:Out of 113 study participants, 80 (70.7%) had pulmonary fungal pathogens whilst those with pulmonary tuberculosis numbered five (4.4%). Candida albicans [21 (22.58%)] and Aspergillus species [16 (17.20%)] were the pathogens most identified among others. Two (1.7%) TB GeneXpert positive participants had fungal pathogens isolated from their sputum samples. We established a prevalence of 57 (71.3%) for pulmonary fungal pathogen (PFP) isolates, three (60.0%) for MTB in HIV positive patients and 18 (22.5%) for PFP, and zero (0.0%) for MTB in HIV negative patients. On the other hand, two (100%) HIV positive patients had both PFP isolates and MTB.Conclusion:Our findings highlight the diversity of neglected pulmonary fungal pathogens whose known medical importance in causing pulmonary mycoses cannot be overemphasised. Therefore this presents a need for routine diagnosis for pulmonary mycoses among TB suspects and set-up of antimicrobial profile for pulmonary fungal isolates to support clinical management of these cases.

Profiling of potential pulmonary fungal pathogens and the prevalence of the association between pulmonary tuberculosis and potential fungal pathogens in presumptive tuberculosis patients referred to Saint Peter's Specialized Tuberculosis Referral Hospital, Addis Ababa, Ethiopia.

Objective:The burden of pulmonary fungal infection is increasing and often misdiagnosed as pulmonary tuberculosis in developing countries where the prevalence of pulmonary tuberculosis is high. |Therefore, the purpose of this study is to determine the spectrum of potential pulmonary fungal pathogens and the prevalence of the association between pulmonary tuberculosis and potential fungal pathogens.Materials and methods:A cross-sectional study was conducted between October 2018 and May 2019. Sputum was collected from 636 study participants. Part of the sputum was inoculated onto Brain Heart Infusion agar, and fungi were identified following standard microbiological procedures. The remaining part of the sample was used for the investigation of pulmonary tuberculosis.Results:Among 636 sputum samples, 75.9% (483) and 25.6% (163) were positive for potential fungal pathogens and pulmonary tuberculosis, respectively. The prevalence of the association between pulmonary tuberculosis and potential fungal pathogens was 20.0%. Of fungal isolates, 81.4% were yeasts. The remaining 128 (18.6%) isolates were molds. The isolation rate of fungi was higher in males (51.6%) than in females (48.4%). There was no statistically significant association between the prevalence of potential pulmonary fungal pathogens and sex (p = 0.239). Patients in the age group of 35 to 44 and above were slightly more affected than younger age groups. The association between potential fungal pathogens and age was not statistically significant (p = 0.50).Conclusion:High prevalence of potential pulmonary fungal pathogens and the association of tuberculosis and potential fungal pathogens recorded in this study will enforce health personnel to pay due attention to these conditions and arise the interest of researchers to conduct further work on the burden of the association between tuberculosis and potential fungal pathogens. Our study also revealed the need to employ conventional microbiology tests along with clinical and radiological evidence since clinical manifestations and radiological pictures of tuberculosis mimic that of pulmonary fungal infection.

Prevalence and Risk Factors of Pulmonary Fungal Pathogens among Symptomatic Patients with or without Tuberculosis at Gombe, Nigeria

Prevalence and Risk Factors of Pulmonary Fungal Pathogens among Symptomatic Patients with or without Tuberculosis at Gombe, Nigeria

Spectrum of pulmonary fungal pathogens, associated risk factors, and anti-fungal susceptibility pattern among persons with presumptive tuberculosis at Gombe, Nigeria.

Pulmonary mycosis (PM) poses a great diagnostic challenge due to the lack of pathognomonic and radiological features, especially in the absence of mycology laboratory tests. This study was aimed to isolate, phenotypically identify, determine the prevalence of pulmonary fungal pathogens and antifungal susceptibility pattern of isolates of presumptive tuberculosis (PTB) patients attending Federal Teaching Hospital (FTH) Gombe, Nigeria. After ethical approval, three consecutive early morning sputa were collected from 216 participants with presumptive of PTB attending FTH Gombe, between May 2, 2017 and May 30, 2018. Samples were processed using standard mycological staining, microscopy, sugar biochemistry, and antifungal susceptibility test protocols. Sociodemographic variables and risk factors of pulmonary fungal infection were assessed through structured questionnaires. Pulmonary fungal infection was defined by the positive culture in at least two sputa. PTB was defined by Genexpert® nested polymerase chain reaction. Of the 216 participants, 19.9% had PTB and 73.6% had pulmonary fungal pathogens. Among the isolated pulmonary fungal pathogens, Aspergillus fumigatus made the highest occurrence, while 6.5% had PTB-fungal co-infection. No significant association existed between the prevalence of PM with age and sex of participants (P < 0.05). Cigarette smoking (adjusted odds ratio [aOR] = 15.9 [95% confidence interval (CI): 0.9-268.8]), prolong antibiotic use (aOR = 77.9 [95% CI: 4.7-1283]) and possession of domestic pet (aOR = 77.9 [95% CI: 4.7-1283]) were significant risk factors of PM (P < 0.05). Penicillium citrinum, Mucor spp. and Aspergillus flavus are more susceptible to voriconazole, and Candida albicans was found to be more susceptible to Nystatin. Of the 159 fungal isolates, 92.5% were resistant to fluconazole. Findings from this study revealed high level pulmonary fungal pathogens, especially among PTB patients. A majority of fungal isolates were resistant to fluconazole. It's recommended that persons should do away with or minimize risk factors for pulmonary fungal pathogens identified in this study.

Pathogenic Fungal Infection in the Lung.

Respiratory fungal infection is a severe clinical problem, especially in patients with compromised immune functions. Aspergillus, Cryptococcus, Pneumocystis, and endemic fungi are major pulmonary fungal pathogens that are able to result in life-threatening invasive diseases. Growing data being reported have indicated that multiple cells and molecules orchestrate the host's response to a fungal infection in the lung. Upon fungal challenge, innate myeloid cells including macrophages, dendritic cells (DC), and recruited neutrophils establish the first line of defense through the phagocytosis and secretion of cytokines. Natural killer cells control the fungal expansion in the lung via the direct and indirect killing of invading organisms. Adaptive immune cells including Th1 and Th17 cells confer anti-fungal activity by producing their signature cytokines, interferon-γ, and IL-17. In addition, lung epithelial cells (LEC) also participate in the resistance against fungal infection by internalization, inflammatory cytokine production, or antimicrobial peptide secretion. In the host cells mentioned above, various molecules with distinct functions modulate the immune defense signaling: Pattern recognition receptors (PRRs) such as dectin-1 expressed on the cell surface are involved in fungal recognition; adaptor proteins such as MyD88 and TRAF6 are required for transduction of signals to the nucleus for transcriptional regulation; inflammasomes also play crucial roles in the host's defense against a fungal infection in the lung. Furthermore, transcriptional factors modulate the transcriptions of a series of genes, especially those encoding cytokines and chemokines, which are predominant regulators in the infectious microenvironment, mediating the cellular and molecular immune responses against a fungal infection in the lung.

Lung Epithelial Cells Coordinate Innate Lymphocytes and Immunity against Pulmonary Fungal Infection

Lung epithelial cells (LECs) are strategically positioned in the airway mucosa to provide barrier defense. LECs also express pattern recognition receptors and a myriad of immune genes, but their role in immunity is often concealed by the activities of "professional" immune cells, particularly in the context of fungal infection. Here, we demonstrate that NF-κB signaling in LECs is essential for immunity against the pulmonary fungal pathogen Blastomyces dermatitidis. LECs orchestrate innate antifungal immunity by augmenting the numbers of interleukin-17A (IL-17A)- and granulocyte-macrophage colony-stimulating factor (GM-CSF)-producing innate lymphocytes, specifically "natural" Th17 (nTh17) cells. Innate lymphocyte-derived IL-17A and GM-CSF in turn enable phagocyte-driven fungal killing. LECs regulate the numbers of nTh17 cells via the production of chemokines such as CCL20, a process dependent on IL-1α-IL-1 receptor (IL-1R) signaling on LECs. Therefore, LECs orchestrate IL-17A- and GM-CSF-mediated immunity in an IL-1R-dependent manner and represent an essential component of innate immunity to pulmonary fungal pathogens.

Lung Epithelial Cells Coordinate Innate Lymphocytes and Immunity against Pulmonary Fungal Infection

Lung epithelial cells (LECs) are strategically positioned in the airway mucosa to provide barrier defense. LECs also express pattern recognition receptors and a myriad of immune genes, but their role in immunity is often concealed by the activities of "professional" immune cells, particularly in the context of fungal infection. Here, we demonstrate that NF-κB signaling in LECs is essential for immunity against the pulmonary fungal pathogen Blastomyces dermatitidis. LECs orchestrate innate antifungal immunity by augmenting the numbers of interleukin-17A (IL-17A)- and granulocyte-macrophage colony-stimulating factor (GM-CSF)-producing innate lymphocytes, specifically "natural" Th17 (nTh17) cells. Innate lymphocyte-derived IL-17A and GM-CSF in turn enable phagocyte-driven fungal killing. LECs regulate the numbers of nTh17 cells via the production of chemokines such as CCL20, a process dependent on IL-1α-IL-1 receptor (IL-1R) signaling on LECs. Therefore, LECs orchestrate IL-17A- and GM-CSF-mediated immunity in an IL-1R-dependent manner and represent an essential component of innate immunity to pulmonary fungal pathogens.

Acute Penicillium marneffei infection stimulates host M1/M2a macrophages polarization in BALB/C mice

BackgroundPenicillium marneffei (P. marneffei) is a thermally dimorphic fungus pathogen that causes fatal infection. Alveolar macrophages are innate immune cells that have critical roles in protection against pulmonary fungal pathogens and the macrophage polarization state has the potential to be a deciding factor in disease progression or resolution. The aim of this study was to investigate mouse alveolar macrophage polarization states during P. marneffei infection.ResultsWe used enzyme-linked immunosorbent (ELISA) assays, quantitative real-time PCR (qRT-PCR), and Griess, arginase activity to evaluate the phenotypic markers of alveolar macrophages from BALB/C mice infected with P. marneffei. We then treated alveolar macrophages from infected mice with P. marneffei cytoplasmic yeast antigen (CYA) and investigated alveolar macrophage phenotypic markers in order to identify macrophage polarization in response to P. marneffei antigens. Our results showed: i) P. marneffei infection significantly enhanced the expression of classically activated macrophage (M1)-phenotypic markers (inducible nitric oxide synthase [iNOS] mRNA, nitric oxide [NO], interleukin-12 [IL-12], tumor necrosis factor-alpha [TNF-α]) and alternatively activated macrophage (M2a)-phenotypic markers (arginase1 [Arg1] mRNA, urea) during the second week post-infection. This significantly decreased during the fourth week post-infection. ii) During P. marneffei infection, CYA stimulation also significantly enhanced the expression of M1 and M2a-phenotypic markers, consistent with the results for P. marneffei infection and CYA stimulation preferentially induced M1 subtype.ConclusionsThe data from the current study demonstrated that alveolar macrophage M1/M2a subtypes were present in host defense against acute P. marneffei infection and that CYA could mimic P. marneffei to induce a host immune response with enhanced M1 subtype. This could be useful for investigating the enhancement of host anti-P. marneffei immune responses and to provide novel ideas for prevention of P. marneffei-infection.

Prevalence and profile of pulmonary fungal pathogens among HIV-infected patients attending University of Maiduguri Teaching Hospital, Nigeria

BackgroundFungal infections in lungs are being diagnosed with increasing frequency. This is related to the increased immunocompromised status and hygienic factors among patients. In view of this, the present study sought to isolate, identify, and determine the prevalence of pathogenic fungi in HIV-infected patients attending the University of Maiduguri Teaching Hospital, Nigeria.Materials and methodsBetween 5 April 2016 and 27 August 2016, three consecutive sputum samples in the early morning were collected from individual participants. The samples were inoculated onto Petri dishes containing sabouraud dextrose agar in triplicates for isolation. The fungal isolates were identified using standard mycological stains and reagents. Self-administered questionnaires and participants’ hospital cards were used to assess demographic and clinical variables, respectively.ResultsThe prevalence of pulmonary fungal infection among the patients was at 68%. Of the infected patients, male patients accounted for 59.8%, whereas female patients accounted for 40.1%. However, there was no significant association between the prevalence of pulmonary fungal infection and sex of subjects (P=0.630). Candida albicans [24 (23.5%)] accounted for the highest proportion of the fungal isolates, followed by Aspergillus spp. [19 (18.6%)], with the least being Torulopsis dattila [one (0.9%)], Torulopsis glabrata, [one (0.9%)], and Microsporum canis [one (0.9%)]. Subjects with ages between 31 and 35 years that the highest prevalence of pulmonary fungal infections, 28 (27.5%), whereas those between 56 and 60 years, had the least prevalence, 1 (20.0%). Among the 102 participants coinfected with HIV/tuberculosis (TB), 92 (90.2%) had fungal coinfections, representing a relatively higher prevalence compared with those without TB, 10 (20.8%). There was statistical association between the prevalence of pulmonary fungal infections and TB status and age of patients (P<0.05).ConclusionFindings from this study revealed a high prevalence of pulmonary fungi in HIV/TB coinfected patients, with C. albicans being the leading causal fungi responsible for symptoms of pulmonary diseases.

Classical versus alternative macrophage activation: the Ying and the Yang in host defense against pulmonary fungal infections.

Macrophages are innate immune cells that possess unique abilities to polarize toward different phenotypes. Classically activated macrophages are known to have major roles in host defense against various microbial pathogens, including fungi, while alternatively activated macrophages are instrumental in immune-regulation and wound healing. Macrophages in the lungs are often the first responders to pulmonary fungal pathogens, and the macrophage polarization state has the potential to be a deciding factor in disease progression or resolution. This review discusses the distinct macrophage polarization states and their roles during pulmonary fungal infection. We focus primarily on Cryptococcus neoformans and Pneumocystis model systems as disease resolution of these two opportunistic fungal pathogens is linked to classically or alternatively activated macrophages, respectively. Further research considering macrophage polarization states that result in anti-fungal activity has the potential to provide a novel approach for the treatment of fungal infections.

Mycological Findings of Sputum Samples from Pulmonary Tuberculosis Patients Attending TB Clinic in Nairobi, Kenya

Objective: To determine the prevalence of fungal pathogens in patients with pulmonary tuberculosis at Mbagathi District Hospital TB clinic. Design: One hundred and seventy two sputum samples were collected from patients who were confirmed to have pulmonary tuberculosis at Mbagathi District Hospital TB clinic. These samples were subjected to mycological investigation using microscopy and culture. Results: Pulmonary fungal pathogens were isolated as co-pathogens with Mycobacterium tuberculosis in 76 (44.18%). Yeasts accounted for 46/172 (26.7%), with 33/172 (19%) being Candida albicans, 3/172 (1.7%) were identified as Candida dubliniensis, 1/172 (0.6%) was Candida guilliermondii, while 3/172(1.7%) were Candida tropicalis. Cryptococcus laurentii was isolated in 2/172 (1.2%). Colonization of Mycobacterium tuberculosis with moulds was as follows: 2/172 (1.2%) Aspergillus flavus, 3/172 (1.7%) Aspergillus fumigatus 4/172 (2.3%) Aspergillus niger, 2/172 (1.2%) Scytalidium hyalinum and 4/172 (2.3%) Trichosporon asahii. Pneumocystis jirovencii oocysts were positive in 19/172 (11.0%) on Toluidine O blue. Gram stain of the sputum samples yielded: 4/172 (2.3%) Gram negative rods, 10/172 (5.8%) Gram positive cocci and 6/172(3.5%) Gram positive rods. Conclusion: Pathogenic fungi and other bacterial pathogens may be significant co-infecting pathogens complicating the management of TB. Clinicians in Kenya should be aware of co-infection of Mycobacterium tuberculosis with opportunistic pulmonary fungal and bacterial pathogens. HIV infection is a significant pre-disposition to pulmonary tuberculosis. The two conditions present severe immunosuppression. Confounded by prolonged TB treatment, this group represents a high risk for acquiring opportunistic fungal pathogens.

Antifungal PK/PD Considerations in Fungal Pulmonary Infections

Pharmacokinetic/pharmacodynamic (PK/PD) studies examine the relationships of drug pharmacokinetic properties, in vitro drug potency, and treatment efficacy. Study results are integral to the design of optimal dosing strategies, prevention of toxicity, development and interpretation of susceptibility break points, and prevention and recognition of drug resistance. These principles are increasingly utilized to optimize therapy for pulmonary fungal pathogens such as ASPERGILLUS species, although they have been underutilized for other difficult-to-treat fungal pathogens. Understanding the design and implementation of PK/PD studies facilitates more effective utilization of the available antifungal agents to improve outcomes for many of these life-threatening infections.

Effect of serum IgG1 to Cryptococcus neoformans glucuronoxylomannan on murine pulmonary infection.

Little is known about the role of Ab in protection against pulmonary fungal pathogens. The ability of murine IgG1 mAb 2H1 to modify pulmonary Cryptococcus neoformans infection was investigated in intratracheal infection. mAb 2H1 binds C. neoformans glucuronoxylomannan. mAb 2H1 was given to A/JCr mice 24 h before infection. Two C. neoformans strains were studied: ATCC 24067 (serotype D) and 62070 (serotype A). Fungal burden was determined by CFU 14 days after infection for both strains, and at 2 h, 24 h, 48 h, 7 days, and 28 days after infection for strain 24067. On day 14, mAb 2H1 treatment reduced CFU in the lung, brain, and liver for strain 62070 infection. Minor reductions in lung CFU followed infection with strain 24067 in mAb 2H1-treated mice, despite prolonged survival. The limited ability of mAb 2H1 to reduce lung CFU may reflect rapid phagocytosis of yeast by alveolar macrophages, seen by electron microscopy 2 h after infection, regardless of whether mice had received mAb. Alveolar macrophages phagocytosed and reduced C. neoformans CFU in vitro only in the presence of mAb 2H1. Differences were apparent in phagocytosis and in vitro killing between strains 24067 and 62070. Serum IgG1 modified the course of pulmonary infection in mice by prolonging survival, reducing CFU, and reducing tissue glucuronoxylomannan Ag. mAb administration was associated with enhanced granulomatous inflammation, but did not prevent infection or dissemination. Despite incomplete protection by serum Ab against pulmonary infection, our results provide encouragement for continued vaccine development.

In vivo and in vitro activation of pulmonary macrophages by IFN-gamma for enhanced killing of Paracoccidioides brasiliensis or Blastomyces dermatitidis.

The fungicidal capacity of murine pulmonary macrophages (PuM) activated in vitro with IFN or lymphokines or in vivo with IFN was studied. PuM treated overnight with IFN (1000 U/ml), Con A-stimulated spleen cell culture supernatants, or lymph node cells plus Con A significantly killed yeast cells of the Gar w isolate of Paracoccidioides brasiliensis 45.5 +/- 2.1%, 72.0 +/- 4.2%, and 51.5 +/- 0.7% respectively. Two other isolates of P. brasiliensis (Ru and LA) were also killed (45 and 34%) by PuM activated by lymph node cells plus Con A. Control PuM had lesser but significant capacity for killing of P. brasiliensis isolates, ranging from 15 to 22%. Killing of P. brasiliensis by PuM activated by Con A-stimulated spleen cell culture supernatants could not be significantly inhibited by superoxide dismutase, catalase, or azide. When mice were treated in vivo with 4 X 10(5) IFN U i.p. and PuM isolated 24 h later, the PuM had significantly enhanced ability to kill P. brasiliensis (47.0 +/- 6.3%) compared with PuM from control mice (25.0 +/- 4.2%). PuM thus activated also showed enhanced killing (43%) of a second isolate compared with control PuM (22%). PuM from IFN-treated mice were able to significantly kill Blastomyces dermatitidis (37.5 +/- 0.7%) compared with control PuM (4.5 +/- 6.3%). These results show that PuM can be activated in vitro and in vivo by IFN for enhanced fungicidal activity against two pulmonary fungal pathogens and suggests that immunologic production of IFN could be an important factor in host defenses against these diseases.