Opportunistic filamentous mycoses: aspergillosis, mucormycosis, phaeohyphomycosis and hyalohyphomycosis

Opportunistic filamentous mycoses are widely distributed all over the world. They are rarely observed in Europe but are common in developing countries. The most common are the aspergilloses (due to Aspergillus spp.) mostly in neutropenia and immunosuppression; the mucormycoses characterized by rapid progression in patients with diabetic ketoacidosis; the phaeohyphomycoses due to pigmented fungi causing either a mild superficial or a very serious deep disease and the hyalohyphomycoses due to hyaline filamentous fungi (Fusarium spp., Pseudallescheria spp., Scopulariopsis spp.). Cutaneous manifestations are usually secondary to dissemination from pulmonary or visceral disease; primary cases are less frequent and due to direct inoculation into the skin. We review epidemiological, clinical, diagnostic, and therapeutic data on the four most important opportunistic filamentous mycoses: aspergillosis, mucormycosis, phaeohyphomycosis and hyalohyphomycosis.     

Etiological agents of superficial mycoses in Kayseri,Turkey

Objective In this study, we aimed to determine the prevalence of agents that cause superficial mycoses and clinical types of superficial mycoses in terms of age and gender in our region were aimed. Methods Five hundred samples of nails, skin and skin with hair taken from 476 children and adult patients pre‐diagnosed with superficial mycoses were examined by direct microscopy and cultural methods between October 2009 and October 2010. Results Fungal elements were determined in 212 (42.4%) of the samples by using direct microscopy. Fungal growth was detected in 111 (22.2%) cultures of the same samples. It was found that the most common agents in superficial mycoses were Trichophyton rubrum (43.7%), Candida spp. (28%) and less often, Aspergillus spp., Malassezia spp., Saccharomyces spp., Rhodotorula spp., Trichosporon spp. and Trichophyton verrucosum. Conclusion The significance of diagnosis by using direct microscopy and culturing together was again shown for the diagnosis of superficial fungal infections that follow a chronic course and affect the quality of life of patients. The most common agents in the superficial mycoses were T. rubrum. With this study, defining the aetiological agents of superficial mycoses in the Kayseri region is expected to contribute to the literature in terms of epidemiological data.     

Superficial mycoses in immunodepressed patients (AIDS)

HIV infection has the capacity to distort the epidemiology and clinical course of infectious diseases, producing atypical manifestations and changing diagnoses. Superficial fungal infections are frequent in HIV-positive/AIDS patients and are no exception. These infections are frequently different in immunodepressed patients (AIDS), with a modified course or exacerbations. This chapter discusses the diagnosis and treatment of superficial mycoses in HIV patients, including cutaneous alterations caused by Candida, dematiaceous fungi agents of phaeohyphomycosis, Malassezia spp, dermatophyte, and filamentous nondermatophyte fungi.     

Antifungal susceptibility patterns of yeasts and filamentous fungi isolated from nail infection

Background Onychomycosis is the nail infection caused by a wide spectrum of fungi species, including yeasts, dermatophytes and filamentous fungi non‐dermatophytes (FFND). This fungal infection represents an important medical problem because it involves the patient′s life quality. Objective The aim was to isolate and identify the fungal agents of onychomycosis, and to determine the in vitro susceptibility to antifungal agents. Methods During the period of March 2008 to March 2009, 114 patients clinically suspected of having onychomycosis were examined. Demographic data, mainly age and gender were obtained from each patient. The nail samples collected (136) were submitted to direct examination with potassium hydroxide 20% and grown on Sabouraud dextrose agar. The in vitro antifungal susceptibility testing was performed according to the method of broth microdilution, recommended by the Clinical Laboratory Standards Institute (CLSI). Results Onychomycosis was observed in 95 (83.3%) patients, including 16 men (16.8%) and 79 women (83.2%), with mean age of 48.1 years. Candida parapsilosis, Trichophyton rubrum and Fusarium spp were the fungi most frequently isolated. The most of the isolated yeasts showed susceptibility to antifungal agents studied. Among filamentous fungi, high MIC values to itraconazole were found for T. rubrum and T. mentagrophytes, while Fusarium spp showed decreased susceptibility to itraconazole and voriconazole. Conclusion C. parapsilosis was the most common fungal species isolated from patients with onychomycosis. The different response obtained by in vitro susceptibility testing to drugs shows the importance of these methods to assist clinicians in choosing the best therapeutic option.     

Endemic systemic mycoses: coccidioidomycosis,histoplasmosis, paracoccidioidomycosis and blastomycosis

Endemic deep or systemic mycoses are common in specific geographical areas of the world. Coccidioidomycosis is present in semi‐desert areas, histoplasmosis and paracoccidioidomycosis in tropical regions and blastomycosis belongs to temperate climates. The two former are widely distributed in the American continent and some tropical regions of the world; the third is limited to Central and South America, and the last to North America and Central and East Africa. These mycoses all have a similar pathogenesis, as the inoculum enters the host through the respiratory tract. Cutaneous manifestations are secondary to lymphatic and hematogenous dissemination. These deep mycoses are exceptional in Europe. Most cases are observed in returning travelers from endemic areas, aid workers, archaeologists, speleologist and immigrants. However, there have been some autochthonous cases of histoplasmosis due to Histoplasma capsulatum var. capsulatum reported in European countries such as Italy and Germany. In this article, we provide up‐to‐date epidemiological, clinical, diagnostic and therapeutic data on the four most important imported systemic mycoses in Europe.     

Prevalence and risk factors for superficial fungal infections among Italian Navy Cadets

BACKGROUND: Limited studies on the prevalence and risk factors for superficial mycoses are available. OBJECTIVE: The aim of this paper was to evaluate the prevalence and risk factors for superficial mycoses (dermatophytes and Candida spp.) in a sample of young Italian people resident at a military school. METHODS: A total of 1,024 young cadets from the Italian Navy Petty Officers School in Taranto, including 975 (95.21%) males and 49 (4.79%) females, mean age 22.5 +/- 3.0 years (range 18-30), were consecutively examined by the same observer. A complete dermatological examination was performed on all the subjects, and skin scrapings for microscopy and fungal culture were obtained from suspected lesions. All the subjects completed a questionnaire providing information on sports practice, swimming-pool attendance, marching, wearing shower sandals, frequent use of 'gummed' shoes, history of severe traumas to the nails, presence of hyperhidrosis and history of superficial mycoses. The affected subjects were also asked if they were aware of their condition. Data were analysed by the Statistical Analysis System, version 8.0. The Fisher exact test and odds ratios were calculated. RESULTS: A total of 33 subjects (3.2%) were found to suffer from a mycologically confirmed fungal infection (3% by dermatophytes and 0.2% by Candida albicans): tinea pedis/Candida intertrigo of the feet was suspected in 126 (12.1%) subjects and confirmed in 30 (2.9%), including 28 cases of tinea pedis and 2 cases of Candida intertrigo; tinea cruris/Candida intertrigo of the groin was suspected in 28 (2.7%) subjects, but confirmed in only 1 case (0.1%); onychomycosis was suspected in 64 (6.1%) subjects and confirmed in 2 cases (0.2%). The organism most frequently responsible in tinea pedis was Trichophyton mentagrophytes var. interdigitale (82.1%). The same species (50%) and T. mentagrophytes var. mentagrophytes (50%) were associated with tinea unguium, Epidermophyton floccosum was the only species detected in tinea cruris. Non-dermatophytic filamentous fungi (Penicillium spp., Fusarium spp., Aspergillus spp. and Paecilomyces spp.), not considered pathogenic, were isolated in 48 samples. None of the risk factors analysed were significantly associated with fungal infection. Only 2 subjects out of the 33 people affected were aware of their condition. They both had tinea pedis. CONCLUSION: The prevalence of mycoses in sailors living in an Italian military school was lower than rates detected in other military populations. This may be due to the cadets' lifestyle and environmental conditions. The most frequent infection was tinea pedis, mainly caused by T. interdigitale. None of the investigated risk factors were significantly associated with the disease, and most of the affected individuals were not aware of their condition.     

Emerging systemic fungal infections

Systemic mycoses are a heterogeneous group of infections caused by different species of fungi that mainly affect individuals with primary or secondary alterations of immunity. In recent years, there has been an increase in the incidence of infections related to migration, AIDS, and other causes of immunosuppression, such as solid organ and bone marrow transplantation; oncological, hematological, and autoimmune diseases; and the use of new drugs. In this paper, we outline the microbiological and epidemiological characteristics of 3 fungi: Aspergillus spp, Fusarium spp, and Penicillium spp. We describe the clinical manifestations of disease with emphasis on those that should alert the dermatologist to make an early diagnosis. We detail the various tools for early diagnosis, prevention, and the epidemiology of different antifungals available for treatment and their mechanism of action and therapeutic efficacy.     

Occurrence of dermatophytoses in patients from the Sistema Único de Saúde

Background: Dermatophytosis is a cutaneous disease caused by filamentous keratinophilic fungi belonging to the genera Trichophyton, Microsporum and Epidermophyton, which present a high prevalence in the general population, being among the most common mycoses affecting about 20% of the world’s population.Objective: To carry out the epidemiological survey of cases of dermatophytosis in patients from the Sistema Único de Saúde in a regional Laboratory in the period of 5 years (2009 to 2013).Methods: A retrospective study (January 2009 to December 2013) was carried out with a qualitative and quantitative design, through the registry book of the laboratory, Mycology Sector, where cases of patients with suspected dermatomycosis were analyzed.Results: In a 5-year period, a total of 4467 cases were suspected of having a fungal infection. Of these, 68.74% (3071) cases were of dermatomycosis. In relation to cultures with fungal growth, 12.54% (385 cases) were dermatophyte fungi and 7.97% (245 cases) non-dermatophyte fungi were isolated. Among the species identified, there was a higher prevalence of T. rubrum complex (75%), T. mentagrophytes complex (11.68%) and M. canis (7.01%). Regarding the sites analyzed, nail involvement was the most frequent in 75% of the cases.Study limitations: This work is representative in the studied region.Conclusions: Dermatomycosis samples are the most frequent among all samples of fungal infections from these patients, with the nail being the most affected area and the fungi T. rubrum complex and T. mentagrophytes complex the most frequent.     

Molecular determination of dermatophyte fungi using the arbitrarily primed polymerase chain reaction

Dermatophytes are keratinophilic fungi capable of causing dermatophytosis (commonly known as tinea or ringworm) in humans and animals. Previously, we reported the differentiation of the common dermatophytes Trichophyton rubrum, T. mentagrophytes and T. tonsurans using a random primer 5′-ACCCGACCTG-3′(OPAA11) in the arbitrarily primed polymerase chain reaction (APPCR). In the present study, by examining additional dermatophytes including eight Microsporum spp., 16 Trichophyton species/subspecies and Epidermophyton floccosum using both OPAA11 and a second random decamer 5′-GAGAGCCAAC-3′(OPD18) in AP-PCR, we show that except for T. rubrum and T. gourvilli, and three T. mentagrophytes varieties, most of the dermatophyte fungi investigated formed distinct DNA band patterns on gel electrophoresis. The amplification of specific DNA bands in APPCR appeared to be independent of culture variations shown by dermatophyte isolates. These results provide the basis for the rapid identification of dermatophytes at the genetic level, supplementing existing laboratory methods and improving the diagnosis of human dermatophytosis.     

Malassezia yeasts activate the NLRP3 inflammasome in antigen‐presenting cells via Syk‐kinase signalling

Although being a normal part of the skin flora, yeasts of the genus Malassezia are associated with several common dermatologic conditions including pityriasis versicolour, seborrhoeic dermatitis (SD), folliculitis, atopic eczema/dermatitis (AE/AD) and dandruff. While Malassezia spp. are aetiological agents of pityriasis versicolour, a causal role of Malassezia spp. in AE/AD and SD remains to be established. Previous reports have shown that fungi such as Candida albicans and Aspergillus fumigatus are able to efficiently activate the NLRP3 inflammasome leading to robust secretion of the pro‐inflammatory cytokine IL‐1β. To date, innate immune responses to Malassezia spp. are not well characterized. Here, we show that different Malassezia species could induce NLRP3 inflammasome activation and subsequent IL‐1β secretion in human antigen‐presenting cells. In contrast, keratinocytes were not able to secrete IL‐1β when exposed to Malassezia spp. Moreover, we demonstrate that IL‐1β secretion in antigen‐presenting cells was dependent on Syk‐kinase signalling. Our results identify Malassezia spp. as potential strong inducers of pro‐inflammatory responses when taken up by antigen‐presenting cells and identify C‐type lectin receptors and the NLRP3 inflammasome as crucial actors in this process.     

Superficial mycoses at the Hospital do Servidor Público Municipal de S?o Paulo between 2005 and 2011

BACKGROUND

Superficial mycoses are fungal infections limited to the outermost layers of the skin. Dermatophytic filamentous fungi and yeasts are the major causative agents of these mycoses. Dermatophytosis is one of the clinical conditions caused by fungal infections most commonly found in dermatological practice. Thus, knowledge of the ecology of dermatophytes provides a better understanding of the natural history of dermatophytosis.

OBJECTIVE

This study aimed to investigate epidemiological and mycological features of superficial mycoses diagnosed from 2005 to 2011 in the Dermatology Clinic of the Hospital do Servidor Público Municipal de São Paulo, Brazil.

METHOD

This retrospective study was conducted in the Laboratory of Medical Mycology at the Dermatology Clinic of the Hospital do Servidor Público Municipal de São Paulo. Mycological examinations of 9042 patients with clinical suspicion of superficial mycoses performed between 2005 and 2011 were reviewed.

RESULTS

Of 9042 direct microscopic examinations, 2626 (29%) were positive for dermatophytes, 205 (2.3%) were positive for Malassezia, 191 (2.1%) were positive for other types of yeast, 48 (0.5%) were positive for bacteria, and 5972 (66%) were negative. Mean age of patients was 48 years, 6920 (77%) patients were female and 2112 (23%) were male.

CONCLUSION

The biota consisted of six dermatophyte species: T. rubrum, T. mentagrophytes, M. gypseum, T. tonsurans, E. floccosum, and M. canis. The most common site of involvement was the nail and foot in adults and scalp in children, with a female predominance. Both Candida and Malassezia were more prevalent in adult women, the former most commonly affecting the interdigital region and nails and the latter the chest and neck.     

Clinical,epidemiological, and therapeutic profile of dermatophytosis

BACKGROUND

The cutaneous mycoses, mainly caused by dermatophyte fungi, are among the most common fungal infections worldwide. It is estimated that 10% to 15% of the population will be infected by a dermatophyte at some point in their lives, thus making this a group of diseases with great public health importance.

OBJECTIVE

To analyze the clinical, epidemiological, and therapeutic profile of dermatophytosis in patients enrolled at the Dermatology service of Universidade do Estado do Pará, Brazil, from July 2010 to September 2012.

METHOD

A total of 145 medical records of patients diagnosed with dermatophytosis were surveyed. Data were collected and subsequently recorded according to a protocol developed by the researchers. This protocol consisted of information regarding epidemiological and clinical aspects of the disease and the therapy employed.

RESULTS

The main clinical form of dermatophyte infection was onychomycosis, followed by tinea corporis, tinea pedis, and tinea capitis. Furthermore, the female population and the age group of 51 to 60 years were the most affected. Regarding therapy, there was a preference for treatments that combine topical and systemic drugs, and the most widely used drugs were fluconazole (systemic) and ciclopirox olamine (topical).

CONCLUSION

This study showed the importance of recurrent analysis of the epidemiological profile of dermatophytosis to enable correct therapeutic and preventive management of these conditions, which have significant clinical consequences, with chronic, difficult-totreat lesions that can decrease patient quality of life and cause disfigurement.     

Evaluation of a polymerase chain reaction-restriction fragment length polymorphism assay for dermatophyte and nondermatophyte identification in onychomycosis

Background  Dermatophytes are the main cause of onychomycoses, but various nondermatophyte filamentous fungi are often isolated from abnormal nails. The correct identification of the aetiological agent of nail infections is necessary in order to recommend appropriate treatment.
Objective  To evaluate a rapid polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay based on 28S rDNA for fungal identification in nails on a large number of samples in comparison with cultures.
Methods  Infectious fungi were analysed using PCR-RFLP in 410 nail samples in which fungal elements were observed in situ by direct mycological examination (positive samples). The results were compared with those previously obtained by culture of fungi on Sabouraud agar from the same nail samples.
Results  PCR-RFLP identification of fungi in nails allowed validation of the results obtained in culture when Trichophyton spp . grew from infected samples. In addition, nondermatophyte filamentous fungi could be identified with certainty as the infectious agents in onychomycosis, and discriminated from dermatophytes as well as from transient contaminants. The specificity of the culture results relative to PCR-RFLP appeared to be 81%, 71%, 52% and 63% when Fusarium spp., Scopulariopsis brevicaulis , Aspergillus spp. and Candida spp., respectively, grew on Sabouraud agar. It was also possible to identify the infectious agent when direct nail mycological examination showed fungal elements, but negative results were obtained from fungal culture.
Conclusions  Improved sensitivity for the detection of fungi in nails was obtained using the PCR-RFLP assay. Rapid and reliable molecular identification of the infectious fungus can be used routinely and presents several important advantages compared with culture in expediting the choice of appropriate antifungal therapy.     

透明丝孢霉病

透明丝孢霉病是指由曲霉以外的无色(透明)真菌所致的皮肤、皮下和深部组织感染。随着近年免疫缺陷人群的增加,该病引起的播散性及侵袭性感染正日益增多,对透明丝孢霉病的做生物学、流行病学、致病机制、临床表现、诊断、治疗与预后等方面进行了综述。     

上海地区青少年浅部真菌病临床及病原菌分析

目的了解上海地区青少年浅部真菌病的发病特点和致病菌种分布情况。方法分析2009年1月-2011年12月本院门诊978例年龄≤18岁浅部真菌病患儿的临床资料,采集标本进行真菌学培养和鉴定。结果皮肤念珠菌病例居首位,共230例(23.52%),白念珠菌为主要致病菌占73.91%;红色毛癣菌在致病菌中分离率最高,占34.15%。结论上海地区青少年浅部真菌病中,应重视以白念珠菌引起的皮肤念珠菌病的防治;同时红色毛癣菌引起的体股癣和手足癣仍是高发病例;头癣致病菌主要为犬小孢子菌。     

Mycetoma: reviewing a neglected disease

Mycetoma caused by either filamentous fungi (eumycotic) or bacteria (actinomycotic) has recently been recognized by the World Health Organization as a neglected tropical disease. Although mycetoma is preventable and treatable, especially in the early stages, it carries high morbidity and a huge socioeconomic burden. Skin and subcutaneous tissue is affected, with a classic presentation of hard woody swellings, discharging sinuses and presence of grains (containing the causative organism). Variants with swelling without sinuses have also been described. Left untreated it may involve underlying bone and muscle, leading to permanent disability. Common actinomycotic species include Streptomyces somaliensis, Actinomadura madurae, Actinomadura pelletieri, Nocardia brasiliensis and Nocardia asteroides, while Madurella mycetomatis, Madurella grisea, Pseudoallescheria boydii and Leptosphaeria senegalensis are common eumycotic agents. Men are more commonly affected than women, and the leg is the most frequently affected site. Diagnosis in suspected lesions is made with the help of grain examination, microscopy, imaging (radiography, ultrasonography, magnetic resonance imaging) and culture, and more recently by molecular methods such as PCR and molecular sequencing. Molecular sequencing for both fungi and bacteria is important for rapid and correct diagnosis, especially in culture‐negative cases. Treatment is long, more successful in actinomycetoma than eumycetoma, and may require a holistic approach comprising antimicrobials, surgery and rehabilitation. Mycetoma can be prevented by simple measures such as wearing protective garments and shoes, especially in rural areas and during outdoor activities.     

Causative agents of onychomycosis — a retrospective study

Background: Dermatophytes, yeasts and moulds all are potential causative agents of onychomycosis.The aim of this study was to determine the percentage of cases of onychomycoses caused by each group. In addition, the responsible genus and species was identified for each nail infection. Patients and Methods: In a retrospective study performed at the Department of Dermatology of the Leipzig University, 5 077 nail samples from 4 177 patients – 2 240 women and 1 937 men – with a variety of nail changes – not just onychomycosis – were investigated. 75% were toenails, 23% fingernails, and 2% from both sites. Results: Both microscopic and/or cultural detection of fungi (dermatophytes, yeasts and moulds) were successful in 54% of samples.Causative fungal agents were: 68% dermatophytes, 29% yeast, and 3% moulds. The most frequently detected dermatophyte species were T. rubrum (91%), and T. mentagrophytes (7.7%).Among yeasts, C. parapsilosis (42%) was most common,followed by C. guilliermondii (20.1%), C. albicans (14.2%), and Trichosporon spp. (10%).Scopulariopsis brevicaularis (43%) was the most frequent mould. The percentage of mixed fungal infections was 22%. Conclusions: Dermatophytes, in particular T.rubrum, but also T. mentagrophytes, are the most frequently isolated causative agents in onychomycosis. In addition, yeasts may be isolated relatively frequently, while moulds are uncommon.     

Characteristics of superficial mycoses in Malta

BACKGROUND: A study was conducted to determine the chief agents of superficial mycoses in Malta. Data were collected over a 5-year period from mycologic investigations carried out on all dermatologic specimens sent to the Mycology Laboratory at St. Luke's Hospital in Malta. METHODS: In the period between January 1995 and December 1999, a total of 1271 specimens from skin, nails, or hair were collected from 1200 clinically suspected cases of dermatomycoses. RESULTS: The fungi cultivated included dermatophytes (n = 371), yeasts (n = 33), and nondermatophyte filamentous fungi (n = 12). Trichophyton rubrum (n = 121) was the most prevalent, followed by Microsporum canis (n = 109), T. mentagrophytes (n = 80), M. gypseum (n = 27), Epidermophyton floccosum (n = 17), T. soudanense (n = 10), T. tonsurans (n = 2), T. verrucosum (n = 2), M. persicolor (n = 1), and T. violaceum (n = 1). Candida species were also cultivated, with C. parapsilosis (n = 14) being the most common, followed by C. albicans (n = 12) and C. tropicalis (n = 6). Nondermatophyte filamentous fungi were isolated from nail specimens only. CONCLUSIONS: In this study, superficial fungal infections were reported more commonly in female (n = 207) than in male (n = 182) patients. M. canis was the chief agent of tinea capitis and tinea corporis, whilst T. rubrum was the main causative agent of tinea pedis, tinea manuum, and tinea unguium. Onychomycosis due to Candida species was more common in female than in male patients.     

Disseminated Fusariosis in a Pediatric Population

Abstract: Members of the genus Fusarium are ubiquitous filamentous fungi that can cause disease in immunocompromised patients. We present a case in which the resistance to conventional antifungal therapies led to a fatal outcome.     

Fungal Skin Infections in Organ Transplant Recipients

Transplantation is now currently and increasingly performed for the treatment of various acute and chronic diseases. Today the kidney, heart, lung, heart-lung, liver, pancreas, kidney-pancreas, small bowel and bone marrow are being transplanted. The immunological status of patients receiving such transplants exposes them to the risk of developing bacterial, viral and fungal infections. The etiological agents of mycotic diseases involving the skin of transplant recipients range from the common dermatophytes through yeasts such as Candida spp., Malassezia spp. and dimorphic fungi to the emerging molds Fusarium spp. and Pseudallescheria boydii. The very wide spectrum of fungi causing cutaneous disease produces equally varied clinical aspects. Lesions may be typical, but are very often aspecific or ambiguous. Cutaneous lesions may be the sign of a trivial mycotic disease or the marker of a disseminated, potentially lethal fungal illness, so great attention should be given to their early recognition. Cutaneous manifestations due to Candida spp., Aspergillus spp., dematiaceous fungi and Pityrosporum folliculitis are usually observed early after transplant, cryptococcosis more than 6 months later, while the frequency of dermatophytoses increases as time goes by. Coccidioides immitis, Histoplasma capsulatum and Blastomyces dermatitidis may appear any time after transplantation. The management of the more severe forms of cutaneous mycosis in transplant recipients is difficult. Besides the fact that early recognition is not easy, there are also problems regarding the effectiveness and the toxicity of the therapy and drug-drug interactions. Prophylactic measures to avoid fungal contamination must be performed during hospitalization; patients should be taught how to avoid contamination, not only during the first period after transplantation, when high dosage immunosuppressive drugs are given, but also later when a normal lifestyle is resumed.