Fungal infections in the immunocompromised host

Portal Dissemination of Fusarium graminearum in a Patient with Acute Lymphoblastic Leukemia and Febrile Neutropenia

We present the case of a man with acute lymphoblastic leukemia and prolonged profound neutropenia, who developed an invasive infection by Fusarium graminearum, acquired via non-cutaneous entry, with gastrointestinal symptoms, sigmoid perforation and liver abscesses due to portal dissemination. The etiologic agent was identified using the 18S-ITS1-5.8S-ITS2-28S rRNA sequence gene, from a liver biopsy. The infection was resolved with surgical drainage and antifungal treatment based on voriconazole. As far as we know, there are no previous reports in the literature of cases of human infection due to Fusarium graminearum.

Gelatin nanoparticles loaded methylene blue as a candidate for photodynamic antimicrobial chemotherapy applications in Candida albicans growth

Gelatin nanoparticles (GN) with an intrinsic antimicrobial activity maybe a good choice to improve the effectiveness of photodynamic antimicrobial chemotherapy (PACT). The aim of this study was to development gelatin nanoparticles loaded methylene blue (GN-MB) and investigate the effect of GN-MB in the Candida albicans growth by PACT protocols. The GN and GN-MB were prepared by two-step desolvation. The nanoparticulate systems were studied by scanning electron microscopy and steady-state techniques, the in vitro drug release was investigated, and we studied the effect of PACT on C. albicans growth. Satisfactory yields and encapsulation efficiency of GN-MB were obtained (yield = 76.0% ± 2.1 and EE = 84.0% ± 1.3). All the spectroscopic results presented here showed excellent photophysical parameters of the studied drug. Entrapment of MB in GN significantly prolongs it's in vitro release. The results of PACT experiments clearly demonstrated that the photosensitivity of C. albicans was higher when GN-MB was used. Gelatin nanoparticles loaded methylene blue-mediated photodynamic antimicrobial chemotherapy may be used against Candida albicans growth.

Composition, in vitro Anti-mildew Fungal Activities of the Heartwood Essential Oil of Chamaecyparis formosensis from Taiwan

In this study, anti-mildew fungal activities of the heartwood essential oil, and its constituents from Chamaecyparis formosensis were evaluated in vitro against 7 mildew fungi. The main compounds responsible for the anti-mildew fungal activities were isolated and identified. The heartwood essential oil of C. formosensis was isolated using hydrodistillation in a Clevenger-type apparatus, and characterized by GC-FID and GC-MS. The heartwood oil consisted primarily of myrtenol (18.4%), cis-myrtanol (14.0%), α-muurolol (13.8%), α-cadinol (12.7%), and chamaecynone (9.8%). The heartwood oil was shown to have excellent anti-mildew fungal activities. Further fractionation of the heartwood oil produced α-cadinol, chamaecynone, α-muurolol, τ-cadinol, and τ-muurolol. The 5 compounds exhibited very strong anti-mildew fungal activities. For the anti-mildew fungal activities of the heartwood oil, the active source compounds were determined to be α-cadinol, chamaecynone, α-muurolol, τ-cadinol, and τ-muurolol.

The Plant Defensin NaD1 Enters the Cytoplasm of Candida Albicans via Endocytosis

Antimicrobial peptides are widespread in nature and are produced by many organisms as a first line of defence against pathogens. These peptides have a broad range of biological activities, such as antibacterial or antifungal activities and act with varied mechanisms of action. A large number of the peptides are amphipathic α-helices which act by disrupting plasma membranes and allowing leakage of intracellular contents. However, some peptides have more complex mechanisms of action that require internalisation into the target organisms’ cytoplasm. The method by which these peptides enter the cytoplasm varies, with some requiring the energy dependent processes of endocytosis or polyamine transport and others entering via passive transport. Here we describe the mechanism that the antimicrobial peptide, the plant defensin NaD1, uses to transverse the fungal membrane and gain access to the fungal cytoplasm. By inhibiting ATP synthesis and using an inhibitor of actin polymerisation, we show that NaD1 is internalised into C. albicans yeast cells by the energy-dependent process of endocytosis.

Airborne fungi in an intensive care unit

The presence of airborne fungi in Intensive Care Unit (ICUs) is associated with increased nosocomial infections. The aim of this study was the isolation and identification of airborne fungi presented in an ICU from the University Hospital of Pelotas - RS, with the attempt to know the place's environmental microbiota. 40 Petri plates with Sabouraud Dextrose Agar were exposed to an environment of an ICU, where samples were collected in strategic places during morning and afternoon periods for ten days. Seven fungi genera were identified: Penicillium spp. (15.18%), genus with the higher frequency, followed by Aspergillus spp., Cladosporium spp., Fusarium spp., Paecelomyces spp., Curvularia spp., Alternaria spp., Zygomycetes and sterile mycelium. The most predominant fungi genus were Aspergillus spp. (13.92%) in the morning and Cladosporium spp. (13.92%) in the afternoon. Due to their involvement in different diseases, the identified fungi genera can be classified as potential pathogens of inpatients. These results reinforce the need of monitoring the environmental microorganisms with high frequency and efficiently in health institutions.

Antifungal Resistance, Metabolic Routes as Drug Targets, and New Antifungal Agents: An Overview about Endemic Dimorphic Fungi

Diseases caused by fungi can occur in healthy people, but immunocompromised patients are the major risk group for invasive fungal infections. Cases of fungal resistance and the difficulty of treatment make fungal infections a public health problem. This review explores mechanisms used by fungi to promote fungal resistance, such as the mutation or overexpression of drug targets, efflux and degradation systems, and pleiotropic drug responses. Alternative novel drug targets have been investigated; these include metabolic routes used by fungi during infection, such as trehalose and amino acid metabolism and mitochondrial proteins. An overview of new antifungal agents, including nanostructured antifungals, as well as of repositioning approaches is discussed. Studies focusing on the development of vaccines against antifungal diseases have increased in recent years, as these strategies can be applied in combination with antifungal therapy to prevent posttreatment sequelae. Studies focused on the development of a pan-fungal vaccine and antifungal drugs can improve the treatment of immunocompromised patients and reduce treatment costs.

Invasive fungal infection in patients with hematologic disorders in a Brazilian tertiary care hospital

INTRODUCTION:

Invasive fungal infections (IFIs) are an important complication in immunocompromised individuals, particularly neutropenic patients with hematological malignancies. In this study, we aimed to verify the epidemiology and diagnosis of IFIs in patients with hematologic problems at a tertiary hospital in Goiânia-GO, Brazil.

METHODS:

Data from 117 patients, involving 19 cases of IFIs, were collected. The collected data included diagnosis methods, demographics, clinical characteristics, and in vitro susceptibility to different antifungal agents. Among the 19 cases, 12 were classified as proven IFI and 7 as probable invasive aspergillosis with detection of galactomannan in blood and presence of lung infiltrates in radiographic images. Logistic regression analysis showed that the proven and probable IFIs were associated with increased risk of death. Statistical analysis demonstrated that age, sex, and underlying disease were not independently associated with risk of death in IFI patients.

RESULTS:

Most bloodstream isolates of Candida spp. exhibited low minimum inhibitory concentrations (MICs) to all antifungal agents tested. Voriconazole and amphotericin had the lowest MICs for Aspergillus spp. and Fusarium spp., but Fusarium spp. showed the least susceptibility to all antifungals tested. Amphotericin B, fluconazole, and itraconazole were found to be inactive in vitro against Acremonium kiliense; but this fungus was sensitive to voriconazole.

CONCLUSIONS:

Considering the high number of IFI cases, with crude mortality rate of 6%, we could conclude that IFIs remain a common infection in patients with hematological malignancies and underdiagnosed ante mortem. Thus, IFIs should be monitored closely.

Fungal Opportunistic Pneumonias in HIV/AIDS Patients: An Indian Tertiary Care Experience

INTRODUCTION

Opportunistic pneumonias are a major cause of mortality and morbidity in Human Immunodeficiency Virus (HIV) reactive patients. Despite the significant role that fungi play in causation of this opportunistic mycoses, very few Indian studies have attempted to investigate the burden and aetiological spectrum of HIV/AIDS-associated fungal pneumonias.

AIM

To document the prevalence of fungal aetiology in HIV/AIDS-related opportunistic pneumonias in an Indian setting; and to elucidate the various fungal opportunists responsible for the same.

MATERIALS AND METHODS

The present study was a prospective, cross-sectional analysis conducted at Maulana Azad Medical College and associated Lok Nayak Hospital, New Delhi from October 2008 to September 2011. Expectorated sputa were collected from 71 HIV reactive patients with a clinical diagnosis of pneumonia and subjected to direct microscopic examination employing Gram stain, 10% KOH wet mount and India ink preparation. In addition, direct immunofluorescence of sputum samples was performed for detection of cysts and trophozoites of Pneumocystis carinii. Also, each sputum sample was inoculated in duplicate onto Sabouraud Dextrose Agar (SDA) for culture. A blood sample was drawn from each patient and a battery of serological tests was performed, including Cryptococcal Antigen Latex Agglutination System (CALAS^TM) for detection of cryptococcal capsular polysaccharide antigen; Platelia™ Aspergillus EIA for detection of Aspergillus galactomannan antigen; SERION ELISA antigenCandida for detection of Candida antigen and Histoplasma DxSelect™ for detecting antibodies to Histoplasma species. Descriptive statistics were employed to depict results as proportions and figures. Further, arithmetic mean and standard deviation were calculated for central tendencies and median for non-normal/skewed distributions.

RESULTS

A definite fungal aetiology was established in 25 (35.2%) of 71 HIV reactive patients with pneumonic involvement. Of these, sputa of 21 patients yielded single fungal isolates, while mixed fungal isolates were reported in four patients. Pneumocystis carinii was the predominant fungal pathogen isolated in our study and was reported in 14 (19.7%) patients. Pulmonary aspergillosis was reported in 7 (9.9%) patients, with Aspergillus flavus (4), Aspergillus fumigatus (2) and Aspergillus niger (1) being the commonly recovered Aspergillus species. Candida pneumonia was documented in 6 (8.5%) patients and the Candida species isolated included Candida albicans in four, Candida glabrata in one and Candida tropicalis in one of these six patients respectively. Pulmonary cryptococcosis was diagnosed in 2 (2.8%) patients; a coexisting cryptococcal meningitis was documented in one of them. Furthermore, antibodies against Histoplasma species were detected in 21 (29.6%) cases suggesting its possible aetiological role.

CONCLUSION

Fungal opportunistic pneumonias are common in HIV reactive patients in Indian setting and warrant a prompt and accurate diagnostic evaluation in the form of a combination of microbiological, serological and histopathological techniques, for an effective prophylactic and therapeutic management.

Cinnamaldehyde and its derivatives, a novel class of antifungal agents

The last few decades have seen an alarming rise in fungal infections, which currently represent a global health threat. Despite extensive research towards the development of new antifungal agents, only a limited number of antifungal drugs are available in the market. The routinely used polyene agents and many azole antifungals are associated with some common side effects such as severe hepatotoxicity and nephrotoxicity. Also, antifungal resistance continues to grow and evolve and complicate patient management, despite the introduction of new antifungal agents. This suitation requires continuous attention. Cinnamaldehyde has been reported to inhibit bacteria, yeasts, and filamentous molds via the inhibition of ATPases, cell wall biosynthesis, and alteration of membrane structure and integrity. In this regard, several novel cinnamaldehyde derivatives were synthesized with the claim of potential antifungal activities. The present article describes antifungal properties of cinnamaldehyde and its derivatives against diverse classes of pathogenic fungi. This review will provide an overview of what is currently known about the primary mode of action of cinnamaldehyde. Synergistic approaches for boosting the effectiveness of cinnamaldehyde and its derivatives have been highlighted. Also, a keen analysis of the pharmacologically active systems derived from cinnamaldehyde has been discussed. Finally, efforts were made to outline the future perspectives of cinnamaldehyde-based antifungal agents. The purpose of this review is to provide an overview of current knowledge about the antifungal properties and antifungal mode of action of cinnamaldehyde and its derivatives and to identify research avenues that can facilitate implementation of cinnamaldehyde as a natural antifungal.

In Vitro Susceptibility and Trailing Growth Effect of Clinical Isolates of Candida Species to Azole Drugs

Background:

Emergence of resistance to respective antifungal drugs is a primary concern for the treatment of candidiasis. Hence, determining antifungal susceptibility of the isolated yeasts is of special importance for effective therapy. For this purpose, the clinical laboratory standard institute (CLSI) has introduced a broth microdilution method to determine minimum inhibitory concentration (MIC). However, the so-called “Trailing effect” phenomenon might sometimes pose ambiguity in the interpretation of the results.

Objectives:

The present study aimed to determine the in vitro susceptibility of clinical isolates of Candida against azoles and the frequency of the Trailing effect.

Materials and Methods:

A total of 193 Candida isolates were prospectively collected and identified through the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Using a broth microdilution test, according to the guidelines of CLSI M27-A3, antifungal susceptibilities of the isolated yeasts against Fluconazole (FLU), Itraconazole (ITR), Ketoconazole (KET) and Voriconazole (VOR) were assessed. Moreover, trailing growth was determined when a susceptible MIC was incubated for 24 hours, and turned into a resistant one after 48 hours of incubation.

Results:

Among the tested antifungal drugs in this study, the highest rate of resistance was observed against ITR (28.5%) followed by VOR (26.4%), FLU (20.8%) and KET (1.5%). The trailing effect was induced in 27 isolates (14.0%) by VOR, in 26 isolates (13.5%) by ITR, in 24 isolates (12.4%) by FLU, and in 19 isolates (9.8%) by KET.

Conclusions:

The monitoring of antifungal susceptibilities of Candida species isolated from clinical sources is highly recommended for the efficient management of patients. Moreover, the trailing effect should be taken into consideration once the interpretation of the results is intended.

Epidemiology of endemic systemic fungal infections in Latin America

Although endemic mycoses are a frequent health problem in Latin American countries, clinical and epidemiological data remain scarce and fragmentary. These mycoses have a significant impact on public health, and early diagnosis and appropriate treatment remain important. The target population for endemic disease in Latin America is mostly represented by low-income rural workers with limited access to a public or private health system. Unfortunately, diagnostic tools are not widely available in medical centers in Latin America; consequently, by the time patients are diagnosed with fungal infection, many are already severely ill. Among immunocompromised patients, endemic mycoses usually behave as opportunistic infections causing disseminated rather than localized disease. This paper reviews the epidemiology of the most clinically significant endemic mycoses in Latin America: paracoccidioidomycosis, histoplasmosis, and coccidioidomycosis. The burdens of disease, typically affected populations, and clinical outcomes also are discussed.

Biofilms isolated from washing machines from three continents and their tolerance to a standard detergent

The goal of this comparative study was to investigate biofilm forming microorganisms living in washing machines (WMs). Biofilms were sampled from 11 washing machines from four countries and three continents. Among the 94 isolated strains, 30% were potential human pathogens. Representative strains were selected and biofilm formation was evaluated with the crystal violet (CV) assay. The majority of the WM isolates formed more biofilm than their reference strains. Biofilms of P. putida WM (the largest biofilm producer) were exposed to different concentrations (0.0007-7 g l(-1)) of the standard detergent IEC-A* at 30°C for 30 min and observed with confocal laser scanning microscopy. Using quantitative CVA, P. putida WM biofilm removal required higher detergent concentrations than the type strain. However, for both strains the recommended detergent concentration (7 g l(-1)) was insufficient to completely clean surfaces from cell debris and exopolymeric substances.

[Skin and mucous membrane manifestations of coccidioidomycosis: a study of thirty cases in the Brazilian states of Piauí and Maranhão]

BACKGROUND

Coccidioidomycosis is a systemic mycosis that usually presents as a benign infection. Patients generally recover spontaneously; however, a small proportion of infected individuals develop progressive complications that may affect the skin in the form of disseminated pleomorphic lesions and may become fatal.

OBJECTIVES

To identify and describe skin and mucous membrane manifestations of coccidioidomycosis, to identify occupational hazards associated with the disease and to determine its associated clinical presentation.

METHODS

A study conducted between 2003 and 2006 involving 30 patients from the Brazilian states of Piauí and Maranhão with coccidioidomycosis diagnosed by direct microscopy, sputum culture or screening serology using agar gel double immunodiffusion, in association with anamnesis and physical examination.

RESULTS

Extrapulmonary lesions were found in 13 cases (43.3%), consisting predominantly of dermatological manifestations of hypersensitivity: erythema nodosum (26.6%), exanthema with erythematosquamous lesions (26.6%) and erythema multiforme (23.3%), as well as ulcerations of the tongue (13.3%), lip ulcers (6.6%) and subcutaneous abscess (3.3%). These manifestations were seen during the acute phase of the disease.

CONCLUSIONS

Skin manifestations associated with an acute respiratory infection reinforce the hypothesis of a diagnosis of coccidioidomycosis, particularly in individuals who hunt armadillos or in those exposed to soil excavation.

Capítulo 1: diagnóstico laboratorial das micoses pulmonares

Nesta era de imunossupressão e transplantes, é imperativa a comunicação entre médicos e laboratoristas devido ao fato de que o diagnóstico de doenças fúngicas, para esses pacientes, deve ser rápido, o que é complicado e requer a cooperação e colaboração de vários profissionais com distintas especializações. Este artigo revisa as técnicas laboratoriais utilizadas para o diagnóstico de infecções fúngicas pulmonares. Os tópicos abordados incluem: fatores relacionados ao hospedeiro, como resposta imunológica e predisposições anatômicas; colheita, armazenamento, remessa e transporte das amostras; processamento laboratorial; exame microscópico direto; técnicas de coloração, cultivo e identificação fúngica; biossegurança em laboratórios; tropismo e reação teciduais; soromicologia; e detecção de antígenos.

A trifungal infection of the mandible: Case report and literature review

Orofacial fungal infections are occasionally seen in the immunocompromised patient. In this case, a patient with a relapse of an acute lymphoblastic leukemia (ALL) developed a fatal mandibular infection. This may be the first reported case of a trifungal infection with zygomycosis, aspergillosis, and candidiasis in the oral cavity and the fifth mandibular zygomycosis case. Epidemiology, diagnosis, treatment and prognosis of zygomycosis infection are reviewed, along with the 4 mandibular zygomycosis cases found in the English literature.

FUNGOS ANEMÓFILOS NA PRAIA DO LARANJAL, PELOTAS, RIO GRANDE DO SUL, BRASIL

RESUMO O crescente interesse por microrganismos alergênicos e a procura de novos indicadores ambientais vem despertando interesse no estudo de fungos anemófilos no Brasil, já que a freqüência e a diversidade dos mesmos podem estar associadas com a poluição ambiental. Para coleta de fungos anemófilos placas de Petri, contendo meio de cultura batata-dextrose-ágar (BDA), foram expostas em 6 pontos representativos na orla da praia do Laranjal, Pelotas, RS. As colônias de aspectos morfológicos diferentes foram repicadas para microcultura e identificadas conforme a micromorfologia, sendo identificados os seguintes gêneros fúngicos: Alternaria, Arthrinium, Aspergillus, Cladosporium, Curvularia, Epicoccum, Fusarium, Gliocladium, Helminthosporium, Nigrospora, Paecilomyces, Penicillium, Pestalotiopsis, Phialomyces, Rhizopus, Scytalidium, Streptomyces, Thysanophora, além de formas não esporuladas. Ocorre uma considerável diversidade de fungos anemófilos, totalizando 18 gêneros, muitos dos quais com potencial para causar micoses e alergias no homem, sendo maior durante o verão e com variações entre os gêneros para cada estação do ano.

Potato dextrose agar antifungal susceptibility testing for yeasts and molds: evaluation of phosphate effect on antifungal activity of CMT-3

The broth macrodilution method (BMM) for antifungal susceptibility testing, approved by the National Committee for Clinical Laboratory Standards (NCCLS), was found to have deficiencies in testing of the antifungal activity of a new type of antifungal agent, a nonantibacterial chemically modified tetracycline (CMT-3). The high content of phosphate in the medium was found to greatly increase the MICs of CMT-3. To avoid the interference of phosphate in the test, a new method using potato dextrose agar (PDA) as a culture medium was developed. Eight strains of fungi, including five American Type Culture Collection strains and three clinical isolates, were used to determine the MICs of amphotericin B and itraconazole with both the BMM and the PDA methods. The MICs of the two antifungal agents determined with the PDA method showed 99% agreement with those determined with the BMM method within 1 log(2) dilution. Similarly, the overall reproducibility of the MICs with the PDA method was above 97%. Three other antifungal agents, fluconazole, ketoconazole, and CMT-3, were also tested in parallel against yeasts and molds with both the BMM and the PDA methods. The MICs of fluconazole and ketoconazole determined with the PDA method showed 100% agreement within 1 log(2) dilution of those obtained with the BMM method. However, the MICs of CMT-3 determined with the BMM method were as high as 128 times those determined with the PDA method. The effect of phosphate on the antifungal activity of CMT-3 was evaluated by adding Na2HPO4 to PDA in the new method. It was found that the MIC of CMT-3 against a Penicillium sp. increased from 0.5 microg/ml (control) to 2.0 microg/ml when the added phosphate was used at a concentration of 0.8 mg/ml, indicating a strong interference of Na2HPO4 with the antifungal activity of CMT-3. Except for fluconazole, all the other antifungal agents demonstrated clear end points among the yeasts and molds tested. Nevertheless, with its high reproducibility, good agreement with NCCLS proposed MIC ranges, and lack of interference of phosphate, the PDA method shows promise as a useful assay for antifungal susceptibility testing and screening for new antifungal agents, especially for drugs that may be affected by high (supraphysiologic) phosphate concentrations.