Fungal infections in cancer patients: an international autopsy survey

Guidelines for Antibiotics Prescription in Critically Ill Patients

How to cite this article: Khilnani GC, Tiwari P, Mittal S, Kulkarni AP, Chaudhry D, Zirpe KG, et al. Guidelines for Antibiotics Prescription in Critically Ill Patients. Indian J Crit Care Med 2024;28(S2):S104-S216.

Primary Pituitary Abscess: Two Case Reports

Introduction  Pituitary abscess is a rare disorder that represents a small fraction of all pituitary lesions. In this report, we present two additional cases with unique features to promote awareness and prompt surgical intervention. Case Presentations  A 42-year-old male presented with headache, photophobia, subjective fever, dizziness, imbalance, nausea, and vomiting. A pituitary hormone panel confirmed hypothyroidism and suggested central hypogonadism and secondary adrenal insufficiency. Magnetic resonance imaging (MRI) showed a large sellar mass measuring 2.5 cm × 1.8 cm × 1.6 cm (CC × XT × AP). A 76-year-old woman presented with several months of headaches and unsteady gait in the setting of a known previously asymptomatic sellar lesion, measuring 1.8 cm × 1.2 cm × 1.5 cm (XT × CC × AP). Repeat MRI demonstrated possible hemorrhage within the lesion. In both cases, a preliminary diagnosis of pituitary macroadenoma was made, but transsphenoidal surgery revealed an encapsulated abscess; cultures obtained from the abscesses stained for gram-positive bacteria. Conclusion  Pituitary abscess is a rare, potentially life-threatening disorder that may be easily mistaken for other sellar lesions. In this review, we contribute two additional cases of pituitary abscesses to increase awareness and emphasize the importance of proper diagnosis and management.

Fungi of the order Mucorales express a "sealing-only" tRNA ligase

Some eukaryotic pre-tRNAs contain an intron that is removed by a dedicated set of enzymes. Intron-containing pre-tRNAs are cleaved by tRNA splicing endonuclease, followed by ligation of the two exons and release of the intron. Fungi use a "heal and seal" pathway that requires three distinct catalytic domains of the tRNA ligase enzyme, Trl1. In contrast, humans use a "direct ligation" pathway carried out by RTCB, an enzyme completely unrelated to Trl1. Because of these mechanistic differences, Trl1 has been proposed as a promising drug target for fungal infections. To validate Trl1 as a broad-spectrum drug target, we show that fungi from three different phyla contain Trl1 orthologs with all three domains. This includes the major invasive human fungal pathogens, and these proteins can each functionally replace yeast Trl1. In contrast, species from the order Mucorales, including the pathogens Rhizopus arrhizus and Mucor circinelloides, have an atypical Trl1 that contains the sealing domain but lacks both healing domains. Although these species contain fewer tRNA introns than other pathogenic fungi, they still require splicing to decode three of the 61 sense codons. These sealing-only Trl1 orthologs can functionally complement defects in the corresponding domain of yeast Trl1 and use a conserved catalytic lysine residue. We conclude that Mucorales use a sealing-only enzyme together with unidentified nonorthologous healing enzymes for their heal and seal pathway. This implies that drugs that target the sealing activity are more likely to be broader-spectrum antifungals than drugs that target the healing domains.

Fungi of the order Mucorales express a "sealing-only" tRNA ligase

Some eukaryotic pre-tRNAs contain an intron that is removed by a dedicated set of enzymes. Intron-containing pre-tRNAs are cleaved by tRNA splicing endonuclease (TSEN), followed by ligation of the two exons and release of the intron. Fungi use a "heal and seal" pathway that requires three distinct catalytic domains of the tRNA ligase enzyme, Trl1. In contrast, humans use a "direct ligation" pathway carried out by RTCB, an enzyme completely unrelated to Trl1. Because of these mechanistic differences, Trl1 has been proposed as a promising drug target for fungal infections. To validate Trl1 as a broad-spectrum drug target, we show that fungi from three different phyla contain Trl1 orthologs with all three domains. This includes the major invasive human fungal pathogens, and these proteins each can functionally replace yeast Trl1. In contrast, species from the order Mucorales, including the pathogens Rhizopus arrhizus and Mucor circinelloides, contain an atypical Trl1 that contains the sealing domain, but lack both healing domains. Although these species contain fewer tRNA introns than other pathogenic fungi, they still require splicing to decode three of the 61 sense codons. These sealing-only Trl1 orthologs can functionally complement defects in the corresponding domain of yeast Trl1 and use a conserved catalytic lysine residue. We conclude that Mucorales use a sealing-only enzyme together with unidentified non-orthologous healing enzymes for their heal and seal pathway. This implies that drugs that target the sealing activity are more likely to be broader-spectrum antifungals than drugs that target the healing domains.

Microbiological Non-Culture-Based Methods for Diagnosing Invasive Pulmonary Aspergillosis in ICU Patients

The diagnosis of invasive pulmonary aspergillosis (IPA) in intensive care unit (ICU) patients is crucial since most clinical signs are not specific to invasive fungal infections. To detect an IPA, different criteria should be considered. Next to host factors and radiological signs, microbiological criteria should be fulfilled. For microbiological diagnostics, different methods are available. Next to the conventional culture-based approaches like staining and culture, non-culture-based methods can increase sensitivity and improve time-to-result. Besides fungal biomarkers, like galactomannan and (1→3)-β-D-glucan as nonspecific tools, molecular-based methods can also offer detection of resistance determinants. The detection of novel biomarkers or targets is promising. In this review, we evaluate and discuss the value of non-culture-based microbiological methods (galactomannan, (1→3)-β-D-glucan, Aspergillus PCR, new biomarker/targets) for diagnosing IPA in ICU patients.

Should patients with acute myeloid leukemia treated with venetoclax-based regimens receive antifungal prophylaxis?

Invasive fungal disease (IFD) is a major complication in patients with acute myeloid leukemia (AML) receiving intensive induction chemotherapy, and the use of anti-mold prophylaxis is considered standard of care. On the other hand, the use of anti-mold prophylaxis in AML patients receiving less-intensive venetoclax-based regimens is not well established, basically because the incidence of IFD may not be high enough to justify primary antifungal prophylaxis. Furthermore, dose adjustments in venetoclax are needed because of drug interactions with azoles. Finally, the use of azoles is associated with toxicity, including liver, gastrointestinal and cardiac (QT prolongation) toxicity. In a setting of low incidence of invasive fungal disease, the number needed to harm would be higher than the number needed to treat. In this paper we review the risk factors for IFD in AML patients receiving intensive chemotherapeutic regimens, the incidence and risk factors for IFD in patients receiving hypomethylating agents alone, and in patients receiving less-intensive venetoclax-based regimens. We also discuss potential problems with the concomitant use of azoles, and present our perspective on how to manage AML patients receiving venetoclax-based regimens without primary antifungal prophylaxis.

LCN2-Fungal siderophore-iron binding and uptake leads to oxidative stress and cell death in hepatocellular carcinoma cell line HepG2

Microorganisms produce non-ribosomal peptides called siderophores for the purpose of iron acquisition. Mammalian immune system is well-known for producing small secretory proteins called lipocalins upon bacterial infection. These proteins sequester siderophores produced by invading bacterial pathogens rendering them unable to acquire iron from the host. However, this is not their sole function. In addition to transferrin and lactoferrin, lipocalins are also known to transport siderophore-bound iron to the host cells. While binding of bacterial siderophores with human lipocalin is well studied, binding of the fungal counterpart is still not confirmed and fully understood. Apart from pathogen-affected cells, developing cancerous cells also show varying expression level of different proteins including those involved in iron transport. The possibility of exogenous fungal siderophore-mediated iron transport via lipocalin and its receptor in mammalian cells has not yet been explored much. In present investigation we have checked differential expression of human lipocalin, LCN2 in hepatocellular carcinoma cell lines HepG2 as well as its normal counterpart WRL-68 and computationally determined the feasibility of LCN2 binding with fungal siderophore. Further in case of a stable complex being formed, whether this complex has the ability to transport iron through its specific receptor was assessed. Also, we have tried to explore possible mechanism of fungal-siderophore mediated oxidative stress leading to significant cell death in cancerous cells. This study will thus be useful towards finding a new way of treating hepatocellular carcinoma via inducing siderophore-mediated cell death in cancerous cells.Communicated by Ramaswamy H. Sarma.

Radiometal chelators for infection diagnostics

Infection of native tissues or implanted devices is common, but clinical diagnosis is frequently difficult and currently available noninvasive tests perform poorly. Immunocompromised individuals (for example transplant recipients, or those with cancer) are at increased risk. No imaging test in clinical use can specifically identify infection, or accurately differentiate bacterial from fungal infections. Commonly used [18F]fluorodeoxyglucose (18FDG) positron emission computed tomography (PET/CT) is sensitive for infection, but limited by poor specificity because increased glucose uptake may also indicate inflammation or malignancy. Furthermore, this tracer provides no indication of the type of infective agent (bacterial, fungal, or parasitic). Imaging tools that directly and specifically target microbial pathogens are highly desirable to improve noninvasive infection diagnosis and localization. A growing field of research is exploring the utility of radiometals and their chelators (siderophores), which are small molecules that bind radiometals and form a stable complex allowing sequestration by microbes. This radiometal-chelator complex can be directed to a specific microbial target in vivo, facilitating anatomical localization by PET or single photon emission computed tomography. Additionally, bifunctional chelators can further conjugate therapeutic molecules (e.g., peptides, antibiotics, antibodies) while still bound to desired radiometals, combining specific imaging with highly targeted antimicrobial therapy. These novel therapeutics may prove a useful complement to the armamentarium in the global fight against antimicrobial resistance. This review will highlight current state of infection imaging diagnostics and their limitations, strategies to develop infection-specific diagnostics, recent advances in radiometal-based chelators for microbial infection imaging, challenges, and future directions to improve targeted diagnostics and/or therapeutics.

Infections in Hospitalized Cancer Patients

Cancer patients are at an increased risk of developing infections that are primarily treatment-driven but may also be malignancy-driven. While cancer treatments such as chemotherapy, radiotherapy, and surgery have been known to improve malignancy morbidity and mortality, they also have the potential to weaken immune defenses and induce periods of severe cytopenia. These adverse effects pave the way for opportunistic infections to complicate a hospitalized cancer patient's clinical course. Understanding the risk each patient inherently has for developing a bacterial, fungal, or viral infection is critical to choosing the correct prophylactic treatment in conjunction with their scheduled cancer therapy. This review discusses the most common types of infections found in hospitalized cancer patients as well as the current guidelines for prophylactic and antimicrobial treatment in cancer patients. In addition, it describes the interaction between antibiotics and cancer therapies for consideration when treating infection in a cancer patient.

Clinical manifestations, associated risk factors and treatment outcomes of Chronic Pulmonary Aspergillosis (CPA): Experiences from a tertiary care hospital in Lahore, Pakistan

Background

Chronic pulmonary aspergillosis (CPA) has a wide spectrum of illnesses depending on the progression of the disease and comorbid conditions. However, there is an inadequacy of investigations regarding clinical, laboratory, risk factor and prognostic data on CPA. The current study is aimed to consider the clinical manifestations, risk factors and outcomes of CPA.

Methodology

Retrospective records of all patients with a confirmed diagnosis of CPA who sought treatment at Gulab Devi Chest Hospital Lahore, Pakistan from January 2017 to December 2019 were evaluated. Data regarding demographics, clinical manifestations, comorbidities, radiographic and microbiological findings, length of hospital stay (LOS) and intensive care unit (ICU) admission was collected and analyzed to identify the factors associated with mortality. The independent factors associated with mortality were also identified by appropriate analyses.

Results

A total of 218 CPA patients were included in this study. The mean age was 45.75 ± 6.26 years. Of these, 160 (73.4%) were male, and 65 (29.8%) had diabetes. The mean LOS was 18.5 ± 10.9 days. The most common type of CPA was simple aspergilloma (56%) followed by chronic cavitary pulmonary aspergillosis (CCPA) (31.2%). About one half of the patients had a history of pulmonary tuberculosis (TB) and treatment response rates were low in patients with active TB. The overall mortality rate was 27.1%. ICU admission was required for 78 (35.8%) patients. Diabetes mellitus (DM), hematological malignancies and chronic kidney disease (CKD) were the common underlying conditions predicting a poor outcome. Mean LOS, hematological malignancies, consolidation and ICU admission were identified as the independent factors leading to mortality.

Conclusions

CPA had a significant association with TB in the majority of cases. Treatment response rates in cases with active TB were comparatively low. Cases with high mean LOS, hematological malignancies, consolidation, ICU admission, CKD and DM experienced poor outcomes. High mean LOS, hematological malignancies, consolidation and ICU stay were identified as independent risk factors for mortality. Future large prospective studies, involving aspergillus specific immunoglobulin G (IgG) antibody testing, are required for a better understanding of CPA in Pakistan.

How I Treat Febrile Neutropenia

The management of febrile neutropenia is a backbone of treating patients with hematologic malignancies and has evolved over the past decades. This article reviews my approach to the evaluation and treatment of febrile neutropenic patients. Key topics discussed include antibacterial and antifungal prophylaxis, the initial workup for fever, the choice of the empiric antibiotic regimen and its modifications, and criteria for discontinuation. For each of these questions, I review the literature and present my perspective.

Evaluation of Three Commercial PCR Assays for the Detection of Azole-Resistant Aspergillus fumigatus from Respiratory Samples of Immunocompromised Patients

This is the first study comparing three commercially available PCR assays for the detection of Aspergillus DNA from respiratory specimen of immunocompromised patients and the presence of cyp51A gene mutations. Bronchoalveolar lavages (BALs, N = 103) from patients with haematological/oncological underlying diseases were retrospectively investigated. The performance of three PCR assays, namely MycoGENIE^®Aspergillus fumigatus Real-Time PCR Kit (Adamtech), Fungiplex^®Aspergillus Azole-R IVD Real-Time PCR Kit (Bruker Daltonik GmbH) and AsperGenius^® (PathoNostics B.V.), were evaluated. All patients were categorised following current EORTC/MSG criteria, with exclusion of the PCR-results. From the 11 invasive pulmonary aspergillosis (IPA) probable samples, eight were detected with MycoGENIE^®, resulting in a sensitivity of 80% and a specificity of 73%. Furthermore, Fungiplex^® resulted in six positive BALs with a sensitivity of 60% and a specificity of 91% and AsperGenius^® in seven positive BAL samples, with a sensitivity of 64% and a specificity of 97%. No proven IPA was detected. One isolate showed phenotypically an azole-resistance, which was also detected in each of the tested PCR assays with the mutation in TR34. The here tested PCR assays were capable of reliably detecting A. fumigatus DNA, as well as differentiation of the common cyp51A gene mutations. However, evaluation on the AsperGenius^® assay revealed a low risk of false positive results.

Fungal brain infection-no longer a death sentence

The aim of this case series was to provide a modern cohort of patients with cerebral aspergillosis and show the effectiveness of modern treatment concepts. In a 10-year period from January 2009 to January 2019, we identified 10 patients (6 male, 4 female) who received surgery or frameless stereotactic drainage of a cerebral aspergilloma at our center. Patients’ and disease characteristics were recorded. The median age was 65 (range 45 to 83). We conducted 133 cranial surgeries in 100 patients due to cerebral brain abscess (BA) during that time, which leads to a percentage of 10% of aspergilloma within BAs in our patient sample. We performed 3.1 surgeries per patient followed by antifungal treatment for 6 months (= median) according to the microbiological findings. Regarding comorbidities, the mean Charlson comorbidity index (CCI) at the time of admission was 5, representing an estimated 10-year survival of 21%. Six (60%) of 10 patients showed conditions of immunosuppression, one suffered endocarditis after replacement of aortic valves. Four patients showed associated frontobasal bone destruction, mycotic aneurysms, or thromboses. The mean duration of hospital stay was 37 days. Mortality was much lower than in literature. Sixty percent of the patients died during the follow-up period. The outcome of the two immunocompetent patients was more favorable. Cerebral aspergillosis is a rare, but still life-threatening, condition, which predominantly occurs in immunosuppressive conditions. Due to radical surgical and antifungal therapy for several months, mortality can be reduced dramatically.

Free circulating mircoRNAs support the diagnosis of invasive aspergillosis in patients with hematologic malignancies and neutropenia

Fungal infections represent a worrisome complication in hematologic cancer patients and in the absence of disease specific symptoms, it is important to establish new biological indicators, which can be used during mould-active prophylaxis. Recently, miRNAs have appeared as candidate diagnostic and prognostic markers of several diseases. A pilot clinical study was performed to evaluate the diagnostic utility of 14 microRNAs which can be related to invasive fungal infections. Based on our data miR-142-3p, miR-142-5p, miR-26b-5p and miR-21-5p showed significant overexpression (p < 0.005) due to invasive aspergillosis in hemato-oncology patients with profound neutropenia. A tetramiR assay was designed to monitor peripheral blood specimens. Optimal cut-off was estimated by using the median value (fold change 1.1) of the log10 transformed gene expressions. The biomarker panel was evaluated on two independent sample cohorts implementing different antimicrobial prophylactic strategies. The receiver operating characteristic analysis with area under the curve proved to be 0.97. Three miRNAs (miR-142-5p, miR-142-3p, miR-16-5p) showed significant expression alterations in episodes with sepsis. In summary, the tetramiR assay proved to be a promising diagnostic adjunct with sufficient accuracy and sensitivity to trace invasive aspergillosis in hemato-oncology patients.

Evaluation of two lateral flow assays in BAL fluids for the detection of invasive pulmonary aspergillosis: A retrospective two-centre study

BACKGROUND

Commonly, the application of radiological and clinical criteria and the determination of galactomannan (GM) in respiratory samples are used as a diagnostic tool for the detection of invasive pulmonary aspergillosis (IPA).

MATERIALS/METHODS

In this study, two lateral flow assays, OLM Aspergillus lateral flow device (LFD) and IMMY sōna Aspergillus Galactomannan lateral flow assay (LFA), were evaluated at two tertiary hospitals in Germany. A total of 200 bronchoalveolar lavage (BAL) samples from patients with suspicion of IPA were analysed retrospectively. LFD and LFA were evaluated against four different criteria: Blot, EORTC/MSG, Schauwvlieghe and extended Blot criteria and additionally against GM.

RESULTS

The evaluation of four algorithms for the diagnosis of IPA showed that there exist good diagnostic tools to rule out an IPA even before results of Aspergillus culture are available. Sensitivities and negative predictive values are generally higher for the LFA than for the LFD in all four criteria. Specificity and positive predictive values varied depending on the classification criteria. The total agreement between the GM and the LFA cube reader (cut-off = 1) was 84%. The correlation between the GM and LFA was calculated with r = 0.8.

CONCLUSION

The here presented data indicate that a negative LFA result in BAL fluid can reliable rule out an IPA in a heterogeneous group of ICU patients based on the original Blot criteria. LFA seems to be a promising immunochromatographic test exhibiting a good agreement with positive GM values.

Chemical composition of material extractives influences microbial growth and dynamics on wetted wood materials

The impact of material chemical composition on microbial growth on building materials remains relatively poorly understood. We investigate the influence of the chemical composition of material extractives on microbial growth and community dynamics on 30 different wood species that were naturally inoculated, wetted, and held at high humidity for several weeks. Microbial growth was assessed by visual assessment and molecular sequencing. Unwetted material powders and microbial swab samples were analyzed using reverse phase liquid chromatography with tandem mass spectrometry. Different wood species demonstrated varying susceptibility to microbial growth after 3 weeks and visible coverage and fungal qPCR concentrations were correlated (R2 = 0.55). Aspergillaceae was most abundant across all samples; Meruliaceae was more prevalent on 8 materials with the highest visible microbial growth. A larger and more diverse set of compounds was detected from the wood shavings compared to the microbial swabs, indicating a complex and heterogeneous chemical composition within wood types. Several individual compounds putatively identified in wood samples showed statistically significant, near-monotonic associations with microbial growth, including C11H16O4, C18H34O4, and C6H15NO. A pilot experiment confirmed the inhibitory effects of dosing a sample of wood materials with varying concentrations of liquid C6H15NO (assuming it presented as Diethylethanolamine).

Different MDSC Activity of G-CSF/Dexamethasone Mobilized Neutrophils: Benefits to the Patient?

Human neutrophils exert a well-known role as efficient effector cells to kill pathogenic micro-organisms. Apart from their role in innate immunity, neutrophils also have the capacity to suppress T cell-mediated immune responses as so-called granulocyte-myeloid-derived suppressor cells (g-MDSCs), impacting the clinical outcome of various disease settings such as cancer. Patients undergoing chemotherapy because of an underlying malignancy can develop prolonged bone marrow suppression and are prone to serious infections because of severe neutropenia. Concentrates of granulocytes for transfusion (GTX) constitute a therapeutic tool and rescue treatment to fight off these serious bacterial and fungal infections when antimicrobial therapy is ineffective. GTX neutrophils are mobilized by overnight G-CSF and/or Dexamethasone stimulation of healthy donors. Although the phenotype of these mobilized neutrophils differs from the circulating neutrophils under normal conditions, their anti-microbial function is still intact. In contrast to the unaltered antimicrobial effector functions, G-CSF/Dexamethasone-mobilized neutrophils were found to lack suppression of the T cell proliferation, whereas G-CSF-mobilized or Dexamethasone-mobilized neutrophils could still suppress the T cell proliferation upon cell activation equally well as control neutrophils. Although the mechanism of how G-CSF/Dex mobilization may silence the g-MDSC activity of neutrophils without downregulating the antimicrobial activity is presently unclear, their combined use in patients in the treatment of underlying malignancies may be beneficial-irrespective of the number of circulating neutrophils. These findings also indicate that MDSC activity does not fully overlap with the antimicrobial activity of human neutrophils and offers the opportunity to elucidate the feature(s) unique to their T-cell suppressive activity.

Evaluation of bioactivities of zinc oxide, cadmium sulfide and cadmium sulfide loaded zinc oxide nanostructured materials prepared by nanosecond pulsed laser

The present study reports the preparation of cadmium sulfide (CdS) loaded zinc oxide (ZnO) nanostructured semiconductor material and its anti-bioactivity studies against cancerous and fungus cells. For composite preparation, two different mass ratios of CdS (10 and 20%) were loaded on ZnO (10%CdS/ZnO, 20%CdS/ZnO) using a 532 nm pulsed laser ablation in water media. The structural and morphological analyses confirmed the successful loading of nanoscaled CdS on the surface of ZnO particles, ZnO particles were largely spherical with average size ~50 nm, while CdS about 12 nm in size. The elemental and electron diffraction analyses reveal that the prepared composite, CdS/ZnO contained both CdS and ZnO, thus reaffirming the production of CdS loaded ZnO. The microscopic examination and MTT assay showed the significant impact of ZnO, CdS, and CdS loaded ZnO on human colorectal carcinoma cells (HCT-116 cells). Our results show that the prepared ZnO had better anticancer activities than individual CdS, and CdS loaded ZnO against cancerous cells. For antifungal efficacy, as-prepared nanomaterials were investigated against Candida albicans by examining minimum inhibitory/fungicidal concentration (MIC/MFC) and morphogenesis. The lowest MIC (0.5 mg/mL), and MFC values (1 mg/mL) were found for 10 and 20%CdS/ZnO. Furthermore, the morphological analyses reveal the severe damage of the cell membrane upon exposure of Candida strains to nanomaterials. The present study suggests that ZnO, CdS, and CdS loaded ZnO nanostructured materials possess potential anti-cancer and anti-fungal activities.

Indian Antimicrobial Prescription Guidelines in Critically Ill Immunocompromised Patients

How to cite this article: Kulkarni AP, Sengar M, Chinnaswamy G, Hegde A, Rodrigues C, Soman R, Khilnani GC, Ramasubban S, Desai M, Pandit R, Khasne R, Shetty A, Gilada T, Bhosale S, Kothekar A, Dixit S, Zirpe K, Mehta Y, Pulinilkunnathil JG, Bhagat V, Khan MS, Narkhede AM, Baliga N, Ammapalli S, Bamne S, Turkar S, Bhat KV, Choudhary J, Kumar R, Divatia JV. Indian Journal of Critical Care Medicine 2019;23(Suppl 1): S64-S96.

Evaluation of a genus-specific ELISA and a commercial Aspergillus Western blot IgG® immunoblot kit for the diagnosis of aspergillosis in common bottlenose dolphins (Tursiops truncatus)

Aspergillosis is a fungal infection with high mortality and morbidity rates. As in humans, its definitive diagnosis is difficult in animals, and thus new laboratory tools are required to overcome the diagnostic limitations due to low specificity and lack of standardization. In this study of common bottlenose dolphins (Tursiops truncatus), we evaluated the diagnostic performance of a new commercial immunoblot kit that had been initially developed for the serologic diagnosis of chronic aspergillosis in humans. Using this in a quantitative approach, we first established its positive cutoff within an observation cohort of 32 serum samples from dolphins with "proven" or "probable" diagnosis of aspergillosis and 55 negative controls. A novel enzyme-linked immunosorbent assay (ELISA) test was also developed for detecting anti-Aspergillus antibodies, and results were compared between the two assays. Overall, the diagnostic performance of immunoblot and ELISA were strongly correlated (P < .0001). The former showed lower sensitivity (65.6% versus 90.6%), but higher specificity (92.7% vs. 69.1%), with no cross-reaction with other fungal infections caused by miscellaneous non-Aspergillus genera. When assessing their use in a validation cohort, the immunoblot kit and the ELISA enabled positive diagnosis before mycological cultures in 42.9% and 33.3% subjects addressed for suspicion of aspergillosis, respectively. There was also significant impact of antifungal treatment on the results of the two tests (P < .05). In all, these new serological methods show promise in aiding in the diagnosis of aspergillosis in dolphins, and illustrate the opportunity to adapt commercial reagents directed for human diagnostics to detect similar changes in other animals.

Diagnosis of invasive fungal diseases in haematology and oncology: 2018 update of the recommendations of the infectious diseases working party of the German society for hematology and medical oncology (AGIHO)

Invasive fungal diseases (IFD) are a primary cause of morbidity and mortality in patients with haematological malignancies. These infections are mostly life-threatening and an early diagnosis and initiation of appropriate antifungal therapy are essential for the clinical outcome. Most commonly, Aspergillus and Candida species are involved. However, other Non-Aspergillus moulds are increasingly identified in case of documented IFD. For definite diagnosis of IFD, a combination of diagnostic tools have to be applied, including conventional mycological culture and non-conventional microbiological tests such as antibody/antigen and molecular tests, as well as histopathology and radiology. Although varying widely in cancer patients, the risk of invasive fungal infection is highest in those with allogeneic stem cell transplantation and those with acute leukaemia and markedly lower in patients with solid cancer. Since the last edition of Diagnosis of Invasive Fungal Diseases recommendations of the German Society for Hematology and Oncology in 2012, integrated care pathways have been proposed for the management and therapy of IFDs with either a diagnostic driven strategy as opposed to a clinical or empirical driven strategy. This update discusses the impact of this additional evidence and effective revisions.

Pulmonary papillary adenocarcinoma with Aspergillus versicolor infection in a dog

Papillary adenocarcinoma of the lungs is the most common primary lung adenocarcinoma, with the feature of papillary-like structure formation by cells. A dog was presented with the primary complaint of vomiting, hyporexia and increased respiratory effort. Thoracic radiography revealed increased soft tissue radiopacity of the right cranial lung lobe suggestive of possible consolidation or collapsed lung lobe, with generalised miliary nodular pattern throughout the other lung fields. The dog was euthanized humanely and necropsy was performed. Histopathology confirmed the diagnosis of primary pulmonary lung neoplasm (papillary adenocarcinoma) with Aspergillus versicolor infection identified through fungal culture and PCR. There have been several reports on humans and dogs with fungal infections that often mimic or coexist with pulmonary neoplasm. This is the first documented report of A. versicolor isolated from a lung neoplasm in a dog in Malaysia.

Purine Acquisition and Synthesis by Human Fungal Pathogens

While members of the Kingdom Fungi are found across many of the world's most hostile environments, only a limited number of species can thrive within the human host. The causative agents of the most common invasive fungal infections are Candida albicans, Aspergillus fumigatus, and Cryptococcus neoformans. During the infection process, these fungi must not only combat the host immune system while adapting to dramatic changes in temperature and pH, but also acquire sufficient nutrients to enable growth and dissemination in the host. One class of nutrients required by fungi, which is found in varying concentrations in their environmental niches and the human host, is the purines. These nitrogen-containing heterocycles are one of the most abundant organic molecules in nature and are required for roles as diverse as signal transduction, energy metabolism and DNA synthesis. The most common life-threatening fungal pathogens can degrade, salvage and synthesize de novo purines through a number of enzymatic steps that are conserved. While these enable them to adapt to the changing purine availability in the environment, only de novo purine biosynthesis is essential during infection and therefore an attractive antimycotic target.

Febrile neutropenia in children with acute lymphoblastic leukemia: single center experience

AIM

An important life-threatening complication of intensive chemotherapy administered in children with leukemia is febrile neutropenia. The objective of this study was to evaluate the clinical features and consequences of febrile neutropenia attacks in children who were treated for acute lymphoblastic leukemia.

MATERIAL AND METHODS

Nighty-six children who received chemotherapy for acute lymphoblastic leukemia in our center between January 1995 and December 2010 were included in the study. The data related to demographic characteristics, treatment features, relapse and febrile neutropenia incidences, risk factors, culture results and prognosis were retrospectively evaluated from the patients' files.

RESULTS

A total of two hundred-ninety nine febrile neutropenia attacks observed in the patients during initial treatment and relapse treatment were evaluated. When the incidence of febrile neutropenia was evaluated by years, it was observed that the patients treated after year 2000 had statistically significantly more febrile neutopenia attacks compared to the patients treated before year 2000. When the incidences of febrile neutropenia during initial treatment and during relapse treatment were compared, it was observed that more febrile neutropenia attacks occured during relapse treatment. Fifty-nine percent of all febrile neutropenia attacks were fever of unknown origin. Eighty microorganisms grew in cultures during febrile neutropenia throughout treatment in 75 patients; 86% were bacterial infections (50% gram positive and 50% gram negative), 8% were viral infections and 6% were fungal infections. Coagulase negative staphylococcus (n=17) was the most frequent gram positive pathogen; E. Coli (n=17) was the most commonly grown gram negative pathogen.

CONCLUSIONS

In this study, it was found that an increase in the incidence of febrile neutropenia occured in years. Increments in treatment intensities increase the incidence of febrile neutropenia while improving survival. Evaluation of febrile neutropenia results by hematology-oncology units in years will be directive in early and successful treatment.

First Line of Defense: Innate Cell-Mediated Control of Pulmonary Aspergillosis

Mycotic infections and their effect on the human condition have been widely overlooked and poorly surveilled by many health organizations even though mortality rates have increased in recent years. The increased usage of immunosuppressive and myeloablative therapies for the treatment of malignant as well as non-malignant diseases has contributed significantly to the increased incidence of fungal infections. Invasive fungal infections have been found to be responsible for at least 1.5 million deaths worldwide. About 90% of these deaths can be attributed to Cryptococcus, Candida, Aspergillus, and Pneumocystis. A better understanding of how the host immune system contains fungal infection is likely to facilitate the development of much needed novel antifungal therapies. Innate cells are responsible for the rapid recognition and containment of fungal infections and have been found to play essential roles in defense against multiple fungal pathogens. In this review we summarize our current understanding of host-fungi interactions with a focus on mechanisms of innate cell-mediated recognition and control of pulmonary aspergillosis.

Fungal empyema thoracis in cancer patients

OBJECTIVES

Fungal empyema thoracis (FET) is a rare life-threatening infection. We sought to describe the clinical characteristics of FET in a large academic cancer center.

METHODS

We conducted a retrospective chart review of all cancer patients who had a fungal isolate from the pleural fluid culture between 1/2005 and 8/2013.

RESULTS

A total of 106 fungal isolates were identified in 97 patients. Yeasts accounted for 62% of the isolates whereas 38% were identified as molds. The most frequent pathogens were Candida spp. (58%) and Aspergillus spp. (12%). All patients with Aspergillus and 83% with Candida met criteria for proven fungal disease. Compared to the Aspergillus group, Candida FET was associated with recent abdominal or thoracic surgical procedures (44% vs. 0%, p = 0.01). Overall, 6-week mortality was high, with no significant differences between Candida and Aspergillus (31% vs. 45%, respectively [p = 0.48]). Only 1 out of 11 patients with uncommon molds died at 6 weeks, despite only 2 of them received appropriate antifungal therapy.

CONCLUSIONS

Development of FET carries a high mortality in cancer patients. A history of a recent surgical procedure is a risk factor for FET due to Candida. Isolation of uncommon molds is likely to represent a contamination of the pleural fluid.

Cryptococcus neoformans infection in malignancy

Cryptococcosis is an opportunistic invasive fungal infection that is well described and easily recognised when it occurs as meningitis in HIV-infected persons. Malignancy and its treatment may also confer a higher risk of infection with Cryptococcus neoformans, but this association has not been as well described. A case of cryptococcosis in a cancer patient is presented, and all cases of coincident C. neoformans infection and malignancy in adults published in the literature in English between 1970 and 2014 are reviewed. Data from these cases were aggregated in order to describe the demographics, type of malignancy, site of infection, clinical manifestations, treatment and outcomes of cryptococcosis in patients with cancer. Haematologic malignancies accounted for 82% of cases, with lymphomas over-represented compared to US population data (66% vs. 53% respectively). Cryptococcosis was reported rarely in patients with solid tumours. Haematologic malignancy patients were more likely to have central nervous system (P < 0.001) or disseminated disease (P < 0.001), receive Amphotericin B as part of initial therapy (P = 0.023), and had higher reported mortality rates than those with solid tumours (P = 0.222). Providers should have heightened awareness of the possibility of cryptococcosis in patients with haematologic malignancy presenting with infection.

Bacteria and genetically modified bacteria as cancer therapeutics: Current advances and challenges

Bacteria act as pro- or anti- tumorigenic agents. Whole bacteria or cytotoxic or immunogenic peptides carried by them exert potent anti-tumor effects in the experimental models of cancer. The use of attenuated microorganism(s) e.g., BCG to treat human urinary bladder cancer was found to be superior compared to standard chemotherapy. Although the phase-I clinical trials with Salmonella enterica serovar Typhimurium, has shown limited benefits in human subjects, a recent pre-clinical trial in pet dogs with tumors reported some subjects benefited from this treatment strain. In addition to the attenuated host strains derived by conventional mutagenesis, recombinant DNA technology has been applied to a few microorganisms that have been evaluated in the context of tumor colonization and eradication using mouse models. There is an enormous surge in publications describing bacterial anti-cancer therapies in the past 15years. Vectors for delivering shRNAs that target oncogenic products, express tumor suppressor genes and immunogenic proteins have been developed. These approaches have showed promising anti-tumor activity in mouse models against various tumors. These can be potential therapeutics for humans in the future. In this review, some conceptual and practical issues on how to improve these agents for human applications are discussed.

Opportunistic Strains of Saccharomyces cerevisiae: A Potential Risk Sold in Food Products

In recent decades, fungal infections have emerged as an important health problem associated with more people who present deficiencies in the immune system, such as HIV or transplanted patients. Saccharomyces cerevisiae is one of the emerging fungal pathogens with a unique characteristic: its presence in many food products. S. cerevisiae has an impeccably good food safety record compared to other microorganisms like virus, bacteria and some filamentous fungi. However, humans unknowingly and inadvertently ingest large viable populations of S. cerevisiae (home-brewed beer or dietary supplements that contain yeast). In the last few years, researchers have studied the nature of S. cerevisiae strains and the molecular mechanisms related to infections. Here we review the last advance made in this emerging pathogen and we discuss the implication of using this species in food products.

Identification and Sequencing of Candida krusei Aconitate Hydratase Gene Using Rapid Amplification of cDNA Ends Method and Phylogenetic Analysis

Background:

The production and development of an effective fungicidal drug requires the identification of an essential fungal protein as a drug target. Aconitase (ACO) is a mitochondrial protein that plays a vital role in tricarboxylic acid (TCA) cycle and thus production of energy within the cell.

Objectives:

The current study aimed to sequence Candida krusei ACO gene and determine any amino acid residue differences between human and fungal aconitases to obtain selective inhibition.

Materials and Methods:

Candida krusei (ATCC: 6258) aconitase gene was determined by 5’Rapid Amplification of cDNA Ends (RACE) method and degenerate Polymerase Chain Reaction (PCR) and analyzed using bioinformatics softwares.

Results:

One thousand-four hundred-nineteen nucleotide of C. krusei aconitase gene were clarified and submitted in Genbank as a partial sequence and then taxonomic location of C. krusei was determined by nucleotide and amino acid sequences of this gene. The comparison of nucleotide and amino acid sequences of Candida species ACO genes showed that C. krusei possessed characteristic sequences. No significant differences were observed between C. krusei and human aconitases within the active site amino acid residues.

Conclusions:

Results of the current study indicated that aconitase was not a suitable target to design new anti-fungal drugs that selectively block this enzyme.

Aspergillus flavus induces granulomatous cerebral aspergillosis in mice with display of distinct cytokine profile

Aspergillus flavus is one of the leading Aspergillus spp. resulting in invasive aspergillosis of central nervous system (CNS) in human beings. Immunological status in aspergillosis of central nervous system remains elusive in case of both immunocompetent and immunocompromised patients. Since cytokines are the major mediators of host response, evaluation of disease pathology along with cytokine profile in brain may provide snapshots of neuro-immunological response. An intravenous model of A. flavus infection was utilized to determine the pathogenicity of infection and cytokine profile in the brain of male BALB/c mice. Enumeration of colony forming units and histopathological analyses were performed on the brain tissue at distinct time periods. The kinetics of cytokines (TNF-α, IFN-γ, IL-12/IL-23p40, IL-6, IL-23, IL-17A and IL-4) was evaluated at 6, 12, 24, 48, 72 and 96h post infection (hPI) in brain homogenates using murine cytokine specific enzyme linked immunosorbent assay. Histological analysis exhibited the hyphae with leukocyte infiltrations leading to formation of granulomata along with ischemia and pyknosis of neurons in the brain of infected mice. Diseased mice displayed increased secretion of IFN-γ, IL-12p40 and IL-6 with a concomitant reduction in the secretion of Th2 cytokine IL-4, and Th17 promoting cytokine, IL-23 during the late phase of infection. A.flavus induced inflammatory granulomatous cerebral aspergillosis in mice, characterized by a marked increase in the Th1 cytokines and neurons undergoing necrosis. A marked increase in necrosis of neurons with concurrent inflammatory responses might have led to the host mortality during late phase of infection.

How we treat invasive fungal diseases in patients with acute leukemia: the importance of an individualized approach

Invasive fungal diseases (IFDs) represent an important cause of treatment failure in adults with acute leukemia. Because of leukemia’s heterogeneity, the risk for IFDs is highly variable. We therefore apply a risk-adapted antifungal strategy with strong emphasis on pretreatment and day-15 posttreatment to allow earlier and more individualized interventions. We determine pretreatment risks for IFDs based on 4 factors: (1) host fitness for standard therapy (ie, fit, unfit, or frail); (2) leukemia resistance (high vs low probability of achieving complete remission [CR]); (3) anticipated treatment-related toxicity such as neutropenia, mucositis, and steroid-induced immunosuppression; and (4) patient exposure to opportunistic fungi. Accordingly, we stratify patients as high, intermediate, or low risk for IFDs and apply risk-adapted antifungal strategies, including primary or secondary prophylaxis and diagnostic-based preemptive or empiric therapy. Prevention of IFDs also relies on optimizing organ function, decreasing exposure to opportunistic fungi, and improving net state of immunosuppression with use of better-tolerated and investigational agents for unfit patients and those with adverse leukemia biology. Novel targeted and safe therapies that can achieve higher rates of sustained CR among patients with adverse genetics offer the best promise for reducing the burden of IFDs in these patients.

The anti-dermatophyte activity of Allium hirtifolium Boiss aqueous extract

In an attempt at demonstrating the efficacy of Allium hirtifolium aqueous extract in control of skin fungal infections as traditional use, we evaluated the anti-dermatophyte activities of A. hirtifolium aqueous extract from bulbs and of ketoconazole against Trichophyton rubrum, Trichophyton mentagrophytes, Microsporum canis, M. gypseum, Trichophyton schoenleinii and Trichophyton verrucosum var. album by food poisoning technique, disc diffusion and micro broth dilution assays. The anti-fungal activity of A. hirtifolium was excellent when it was compared with ketoconazole. The anti-fungal evaluation by food poisoning method showed that A. hirtifolium extract inhibited the growth of dermatophytes dose-dependently. The inhibition zone diameter (IZ) of A. hirtifolium extract (15 μg/disc) was in the range of 28.8 ± 0.31 to 67.7 ± 1.5mm, while ketoconazole (15 μg/disc) had the IZ lower than 13mm. The MIC and MFC values of A. hirtifolium extract were in the range of 0.2-1.7 and 0.4-0.7 μg/mL; respectively. Therefore, A. hirtifolium extract showed a strong anti-fungal activity against human and animal dermatophytes.

Invasive aspergillosis caused by Aspergillus terreus: an emerging opportunistic infection with poor outcome independent of azole therapy

OBJECTIVES

Invasive aspergillosis (IA) caused by Aspergillus terreus is a significant cause of morbidity and mortality in patients with haematological malignancy (HM). Very few data are available in this patient population to differentiate IA patients with A. terreus from those with non-terreus species of Aspergillus to compare outcomes. We retrospectively investigated 513 HM patients who were treated for either definite or probable IA between June 1993 and August 2012 in a cancer centre.

METHODS

We compared baseline characteristics, antifungal therapies and outcomes between patients infected with A. terreus (n = 96, 18.7%) and those infected with non-terreus Aspergillus species (n = 335, 65.3%). Eighty-one patients with mixed or unspecified Aspergillus infections were excluded.

RESULTS

Breakthrough infections occurred more frequently in the A. terreus group (91% versus 77%, P = 0.009). A. terreus infection was associated with a lower rate of final response to antifungal therapy (21% versus 38%, P = 0.0015) and a higher rate of IA-associated mortality (51% versus 30%, P < 0.001). Multivariate analyses showed that these associations were independent of patients' clinical characteristics and the antifungal regimens they received. Factors independently associated with final response included treatment with azoles (OR 3.1, 95% CI 1.9-5.0, P < 0.0001) and Aspergillus species (A. terreus versus non-terreus Aspergillus species) (OR 0.5, 95% CI 0.3-0.98, P = 0.043). Additionally, Aspergillus species and treatment with azoles were independently associated with IA-associated mortality.

CONCLUSIONS

A. terreus IA in HM patients was associated with worse outcome than IA caused by non-terreus Aspergillus species. Poor prognosis in patients with invasive A. terreus infections is independent of anti-Aspergillus azole-based treatment.

Discovery and development of first in class antifungal caspofungin (CANCIDAS®)--a case study

Covering: 1985 to 2001.This paper describes a fifteen year journey from concept to clinical discovery and development of the first in class caspofungin acetate (CANCIDAS®) a parenteral antifungal agent. Caspofungin is a semisynthetic derivative of pneumocandin B0, a naturally occurring, lipophilic cyclic peptide isolated from the fungus, Glarea lozoyensis. While the echinocandins had been previously studied for antifungal activity by several organizations, the class was dropped for a variety of reasons. Merck subsequently initiated a research program leading to the discovery and development of caspofungin. The multitude of challenges that ensued during the discovery and development process and which were successfully resolved by multi-disciplinary teams constitute the content of this article. The article consists of five sections that describe the discovery and development of caspofungin in chronological order: (i) discovery of the natural product pneumocandin B0 from fungal fermentations, (ii) fermentation development to improve the titer of pneumocandin B0 to make it commercially viable, (iii) semisynthetic modification by medicinal chemistry to successfully improve the properties of pneumocandin B0 leading to the discovery of caspofungin, (iv) development of commercial semisynthesis and purification and formulation development to improve stability and (v) clinical development and approval of CANCIDAS® as an antifungal drug which subsequently saved thousands of lives.

Host impairments in patients with neoplastic diseases

Healthy individuals possess an immune system comprising physical barriers, innate and acquired immunity as well as the indigenous microflora that populate the body surfaces. The immune system maintains constant vigilance over the body at the cellular level as well as at the interface between the host integument and the resident microflora. However, neoplastic diseases and their treatment often lead to impaired immunity resulting in an increased risk of infections due to viruses, bacteria, fungi, and protozoa. This chapter explores the various aspects of host impairment focusing on the components of immunity and the interplay between them to explain why it is that these patients succumb to infections per se. In so doing, we hope that the reader will be better equipped to understand the risks patients face so as to anticipate potential infectious complications and implement appropriate measures to help attain successful remission of the neoplastic diseases and maintain the best quality of life for the patient.

Fungal infections of the central nervous system

The epidemiology of invasive fungal infections in immunocompromised patients is rapidly changing. Several of the fungi have worldwide distribution. However, some have specific geographical distribution. Sinocranial aspergillosis, mostly described from countries with temperate climates, occurs mostly in otherwise immunocompetent individuals Most of the systemic fungal pathogens have been associated with central nervous system (CNS) involvement. The major advances in CNS fungal infections are in the pathobiology, new diagnostic tools, and new therapies. In spite of these developments, there is still considerable delay in the diagnosis of CNS fungal infection. CNS fungal infections are associated with considerable morbidity and mortality. To achieve good outcomes early diagnosis and early institution of appropriate therapies are the key issues.

Epidemiology of infections in cancer patients

Although major advances in the care of cancer patients over the past several decades have resulted in improved survival, infectious complications remain a significant cause of morbidity and mortality. To successfully identify, treat, and prevent infections, a comprehensive understanding of risk factors that predispose to infection and of commonly encountered pathogens is necessary. In addition, clinicians must keep abreast of the changing epidemiology of infections in this population. As therapeutic modalities continue to evolve, as established pathogens become increasingly drug resistant, and as new pathogens are discovered, successful management of infections will continue to present challenges in the years to come.

An autopsy case of pulmonary fissure induced by zygomycosis

For immunodeficient patients, fungi are life-threatening pathogens. In this paper, we present an autopsy case of combined zygomycosis and aspergillosis. A female in her 70s on chronic hemodialysis was admitted to a hospital suffering bloody sputum, dyspnea, and fever, probably due to perinuclear anti-neutrophil cytoplasmic antibody-related vasculitis. Antibiotics were administered and immunosuppressive therapy was started, resulting in an improvement in her condition. Pneumonia later developed, followed by pulmonary bleeding and intractable pneumothorax from which she ultimately died. On autopsy, the upper lobe of the left lung was found to have hemorrhagic necrosis and showed a large longitudinal fissure. Microscopically, Zygomycota were observed in both the lungs and heart, while Aspergillus was found in the middle lobe of the right lung. Zygomycosis, which usually has a poor prognosis, is assumed to have induced hemorrhagic infarction of the lungs, inducing pulmonary bleeding and necrosis, despite the use of lipid formulations of amphotericin B, which are effective medicines against Zygomycota.

Assessment of phytochemicals, antimicrobial and cytotoxic activities of extract and fractions from Fagonia olivieri (Zygophyllaceae)

BACKGROUND

In Pakistan Fagonia olivieri (Zygophyllaceae) is commonly used in the indigenous system of medicine for treatment of conditions like diabetes, cancer, fever, asthma, toothache, stomach troubles and kidney disorders. This study evaluated the crude methanol extract of F. olivieri (FOM) and its derived fractions for their antimicrobial and cytotoxic activities as well as the classes of phytochemical.

METHODS

Dried powder of whole plant of F. olivieri was extracted with methanol (FOM) and the resultant was fractionated to give n-hexane fraction (FOH), chloroform fraction (FOC), ethyl acetate fraction (FOE), n-butanol fraction (FOB) and residual aqueous fraction (FOA). Methanol extract and its derived fractions were subjected to phytochemical screening using standard procedures. Also the extract and fractions were assayed for antibacterial, antifungal and cytotoxic activities using agar well diffusion technique, agar tube dilution method and brine shrimps lethality test, respectively.

RESULTS

The results obtained for phytochemical analysis indicate the presence of saponins and alkaloids in all the tested extract and fractions while anthraquinones were not detected. The results showed that all the bacterial strains tested in this study were susceptible to at least one of the fractions tested. However, FOE and FOB were the best antibacterial fractions and showed antibacterial activity against maximum number of bacterial strains. The results showed that Escherichia coli was the most sensitive bacterium while Bordetella bronchiseptica and Enterobacter aerogenes were less susceptible against various fractions. Maximum percent inhibition for growth was recorded for the fungus Aspergillus flavus with FOE whereas growth of Aspergillus fumigatus and Fusarium solani was inhibited by FOM and its all derived fractions. Minimum LC50 (24.07 mg/L) for brine shrimp assay was recorded for FOE followed by LC50 of FOC (26.1 mg/L) and FOB (30.05 mg/L) whereas maximum LC50 was exhibited by FOH (1533 mg/L).

CONCLUSION

These results indicated the use of F. olivieri to treat infections with emphasis to isolate and characterize the active principle responsible for antibacterial, antifungal and cytotoxic activities and its exploitation as therapeutic agent.

Silver nanoparticles as active ingredient used for alcohol-free mouthwash

We developed an effective and non-irritant mouthwash that is alcohol-free and has a low concentration of silver nanoparticles (SNP) in order to be used for preventing oral cavity infections in immunocompromised oncologic patients. We studied antimicrobial effects of silver nanoparticles (SNP) in the range of (50-0.024 µg/ml) and 3% of ethanol (30,000 µg/ml) in mouthwash. Antimicrobial effects of two treatments were studied by doing challenge test on microorganisms such as Streptococcus mutans, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Candida albicans and measuring MIC and MBC (MFC) values of SNP toward mentioned microorganisms. These values of SNP respectively were in the range of (0.78-3.12) and (1.56-12.5 µg/ml). Results showed that SNP in the MIC and the lower concentrations killed all of the used microorganisms. No difference was observed between the antimicrobial effect of ethanol-free mouthwash containing SNP and mouthwash containing SNP and ethanol (30,000 µg/ml). SNP has high antimicrobial effects at low concentrations and it can be a good alternative for ethanol (30,000 µg/ml) because ethanol is also irritating, especially to sensitive or inflamed mucosa.