Onychomycosis byChaetomiumspp

Identification of Dermatophyte and Nondermatophyte Molds Isolated from Animal Lesions Suspected to Dermatomycoses

Background:

Dermatomycoses contain superficial fungal infections of keratinized layers of the body such as skin, hair, and nail that affect more than 20%–25% of people and animals worldwide. Some fungi can cause superficial infections in animals after accidental penetration and colonization on injured skin and can be transmitted to humans by exposure. The infection caused mainly by dermatophyte species and may also be caused rarely by yeasts and nondermatophytic molds.

Materials and Methods:

Eighty-two skin scrapings and hair samples were collected from animals (sheep, cow, cat, camel, calf, goat, horse, and dog) in three specialized pet clinics and three livestock and slaughterhouses. The isolates were identified using direct microscopy, culture, and polymerase chain reaction-sequencing of ITS1-5.8SrDNA-ITS2 region.

Results:

Thirteen mold strains out of 82 clinical samples (15.8%) were isolated from animal lesions. Acremonium exuviarum (n = 4; 30.7%), Sarocladium implicatum (n = 2; 15.4%), Arthroderma otae (n = 2; 15.4%), Chaetomium iranianum (n = 1; 7.7%), Trichothecium roseum (n = 1; 7.7%), Lichtheimia ramosa (n = 1; 7.7%), Penicillium chrysogenum (n = 1; 7.7%), and Microsporum equinum (n = 1; 7.7%) were isolated from clinical specimens.

Conclusion:

Since opportunistic fungi are increasing as etiological agents of dermatomycoses, isolation of these molds from wounds can be a warning to veterinarians, and daily cleaning of wounds with a proper disinfectant is recommended for the prevention of fungal colonization.

Onychomycosis due to Achaetomium strumarium

Onychomycosis is the most common infection of the toe-nails or finger-nails and it may be caused by a large variety of fungal species. Achaetomium species which belong to the phylum Ascomycota (Family Chaetomiaceae), are usually soil saprophytes or endophytic fungi which have been rarely reported as human or animal pathogens. Here, we report a case of onychomycosis caused by Achaetomium strumarium in a healthy person who showed involvement of all fingers of both hands with yellowish brown discoloration. The causative agent isolated was identified as Achaetomium species by morphology, colony morphometry and growth at high temperature and as A. strumarium from DNA sequence of ITS region. Onychomycosis from this case responded satisfactorily with per os (P. O.; oral) and topical application of Terbinafine.

Chaetomium atrobrunneum and Aspergillus fumigatus in multiple tracheal aspirates: Copathogens or symbiosis

Chaetomium atrobrunneum has never been reported to be associated with pneumonia. We report the isolation of C. atrobrunneum and Aspergillus fumigatus from a Chinese elderly patient with fatal pneumonia. Branched, long, and septate hyphae were observed in potassium hydroxide preparations and Gram-stained smears, and confluent C. atrobrunneum growth and a few A. fumigatus colonies were found in tracheal aspirates (nine separate occasions). These isolates were identified by conventional morphological methods and by sequencing the internal transcribed spacer and the D1/D2 domain of the 26S rRNA gene. The patient responded poorly to the combination therapy of amphotericin B and caspofungin. This report adds C. atrobrunneum to the list of fungal pneumonia in immunocompromised hosts. This case report also illustrated the presence of a growth symbiosis between Chaetomium species and A. fumigatus.

Invasive pulmonary mycosis due to Chaetomium globosum with false-positive galactomannan test: a case report and literature review

In this case, the authors report Chaetomium globosum as a cause of invasive pulmonary infection in a patient with Wegener's granulomatosis. Fungal hyphae (KOH and Calcofluor) were seen on direct microscopy of lung biopsy sample and bronchoalveolar lavage (BAL) sample. C. globosum isolated on culture clinched the diagnosis of invasive pulmonary infection by Chaetomium spp. A positive galactomannan of serum and BAL was repeatedly seen and was utilised for follow-up and as prognostic marker in patient management. The patient was successfully treated with liposomal amphotericin B followed by voriconazole. All the Chaetomium infections reported till date since 1980 are reviewed. Chaetomium spp. with its unique ecology has a hidden clinical potential to cause invasive mould infections.

Onychomycosis Caused by Chaetomium globosum

Onychomycosis is usually caused by dermatophytes, but some nondermatophytic molds and yeasts are also associated with invasion of nails. The genus Chaetomium is a dematiaceous nondermatophytic mold found in soil and plant debris as a saprophytic fungus. We report the first Korean case of onychomycosis caused by Chaetomium globosum in a 35-year-old male. The patient showed brownish-yellow discoloration and subungual hyperkeratosis on the right toenails (1st and 5th) and left toenails (1st and 4th). Direct microscopic examination of scraping on the potassium hydroxide preparation revealed septate hyphae and repeated cultures on Sabouraud's dextrose agar (SDA) without cycloheximide slants showed the same fast-growing colonies, which were initially velvety white then turned to dark gray to brown. However, there was no growth of colony on SDA with cycloheximide slants. Brown-colored septated hyphae, perithecia and ascospores were shown in the slide culture. The DNA sequence of internal transcribed spacer region of the clinical sample was a 100% match to that of C. globosum strain ATCC 6205 (GenBank accession number EF524036.1). We confirmed C. globosum by KOH mount, colony, and light microscopic morphology and DNA sequence analysis. The patient was treated with 250 mg oral terbinafine daily and topical amorolfine 5% nail lacquer for 3 months.

Systemic antifungals to treat onychomycosis in children: a systematic review

Because of the low prevalence of onychomycosis in children, little is known about the efficacy and safety of systemic antifungals in this population. PubMed and Embase databases and the references of related publications were searched in March 2012 for clinical trials (CTs), retrospective analyses (RAs), and case reports (CRs) on the use of systemic antifungals for onychomycosis in children (<18 years). Twenty-six studies (5 CTs, 3 RAs, and 18 CRs) were published between 1976 and 2011. Most of these studies reported the use of systemic terbinafine and itraconazole for the treatment of onychomycosis in children. Therapy with systemic antifungals alone in children ages 1 to 17 years resulted in a complete cure rate of 70.8% (n = 151), whereas combined systemic and topical antifungal therapy in one infant and 19 children age 8 and older resulted in a complete cure rate of 80.0% (n = 20). The efficacy and safety profiles of terbinafine, itraconazole, griseofulvin, and fluconazole in children were similar to those previously reported for adults. In conclusion, based on the little information available on onychomycosis in children, systemic antifungal therapies in children are safe and cure rates are similar to the rates achieved in adults.

A case report of a mixed Chaetomium globosum/Trichophyton mentagrophytes onychomycosis

Recently, an increasing prevalence of nondermatophyte mold onychomycosis was observed, in which Chaetomium globosum was rarely involved as primary pathogenic agent. Besides this, reports of mixed infection associating a dermatophyte and a nondermatophyte mold have become more frequent. Here, we present a clinical case of a mixed onychomycosis infection of a toenail caused by Chaetomium globosum and Trichophyton mentagrophytes. To our knowledge, this specific association is reported for the first time in Canada.

Phaeohyphomycosis and onychomycosis due to Chaetomium spp., including the first report of Chaetomium brasiliense infection

Chaetomium species have been rarely described as aetiological agents of invasive and dermatomycotic infections in humans. The majority of cases have been reported within the last two decades. Treatment failed in most of these cases. In this paper we present two cases in which Chaetomium spp. can be clearly identified as an aetiological agent in pathological conditions. In the first report, we describe a new aetiological agent, Chaetomium brasiliense, which was implicated in a case of otitis externa in a patient with spinocellular carcinoma basis cranii. The patient had been repeatedly treated for relapsing otitis externa and had previously undergone surgery several times for otitis media. The fungal aetiology was confirmed by repeated positive culture and histologic studies. The second case involved onychomycosis with strikingly brown nail discoloration due to Chaetomium globosum in an otherwise healthy patient. The nail lesion was successfully cured by oral terbinafine. The determination of both species was supported by sequencing of rDNA regions. The morphological aspect of Chaetomium spp. identification is also discussed. In vitro antifungal susceptibility tests demonstrated that both isolates were susceptible to terbinafine and azole derivates except fluconazole. Amphotericin B was effective only against the C. brasiliense strain. We review the literature to summarize clinical presentations, histologic findings, and treatment strategies.

Clavispora lusitaniae and Chaetomium atrobrunneum as rare agents of cutaneous infection

We describe the first case of cutaneous infection caused by Chaetomium atrobrunneum and Clavispora lusitaniae in a one-and-a-half-year-old boy with acute and severe inflammation around his left eyelid. He presented to our outpatient center with a 6-day history and previously ineffective antibacterial therapy. Scanning electron microscopy (SEM) revealed hyphae and spores were on the surface of the crusty exudates and also penetrated into it, and the microbiology study further showed their characteristic cultural features. Fungal isolates were identified by the amplification and sequencing of the 26S RNA gene and of the ITS region, as C. lusitaniae and C. atrobrunneum. Up until now, most known clinical records of these rare species have shown them as agents of deep mycosis. Due to the emergency situation, medications were administered promptly and confirmed by subsequent fungal identification and successful therapeutic outcome. This article illustrates the importance of recognizing fungal infections, especially those caused by uncommon pathogens. Limitations in the routine identification procedures and therapeutic options of this emerging opportunistic agent are also discussed in this report.

NB-002, a novel nanoemulsion with broad antifungal activity against dermatophytes, other filamentous fungi, and Candida albicans

NB-002 is an oil-in-water emulsion designed for use for the treatment of skin, hair, and nail infections. The activity of NB-002 was compared to the activities of the available antifungal drugs against the major dermatophytes responsible for cutaneous infections, Trichophyton rubrum, Trichophyton mentagrophytes, Epidermophyton floccosum, and Microsporum spp., as well as 12 other genera of filamentous fungi. NB-002 consistently displayed fungicidal activity against all dermatophytes. The comparator compounds were either fungistatic or fungicidal, and for some strain-drug combinations, tolerance was observed. Assessment of the development of spontaneous resistance to NB-002 in different dermatophyte species yielded few stably resistant mutants. For filamentous nondermatophyte fungi, the MIC range varied from 0.06 to 0.5 microg/ml for Alternaria spp. to 2 to 8 microg/ml for Paecilomyes spp. NB-002 had activity against both azole-susceptible and -resistant Candida albicans yeast isolates, with MIC(90)s of 2 microg/ml, respectively, and minimum fungicidal concentrations at which 90% of isolates are inhibited of 4 and 8 microg/ml, respectively. The kinetics of the fungicidal activity of NB-002 against T. rubrum isolates were compared to those of the other antifungal drugs. NB-002 killed both mycelia and microconidia even when the fungal forms were dormant or not actively growing. Electron micrographs of mycelia and spores treated with NB-002 showed the significant disruption of the fungal structure. The in vitro broad coverage of NB-002 against filamentous fungi, dermatophytes, and C. albicans, as well as its rapid fungicidal activity, warrants further investigations to ascertain if NB-002 would be useful for the treatment of cutaneous mycoses.