The First Case of Total Dystrophic Onychomycosis Caused by Aspergillus clavatus Resistant to Antifungal Drugs

Septic Obturation of a Knee Endoprosthesis Caused by Aspergillus clavatus

Aspergillus clavatus is a rare opportunistic fungal pathogen that can be isolated from various environmental sources, including soil and animal feces. Although infrequent, infections caused by A. clavatus can be severe in immunocompromised patients. Here, we present a case of a prosthetic joint infection (PJI) in a 74-year-old female patient caused by A. clavatus. The patient presented with left knee pain, and septic loosening of the left knee endoprosthesis was diagnosed. She underwent surgical revision with the implantation of an antibiotic spacer and microbiologic testing. The results came back positive for both Staphylococcus lugdunensis and A. clavatus (which is found in only a fraction of a percent of PJIs). She was treated with oral antimicrobials for 3 months postoperatively. This case report vividly illustrates a clinical scenario that underscores the significance of rigorous microbiologic testing procedures, accurate pathogen identification, unwavering vigilance in testing protocols, and a cautious approach that avoids succumbing to the seductive simplicity of Occam's razor.

Isolation, Characterization, and Antifungal Sensitivity Pattern of Fungal Species with Potential Resistance to Antifungal Drugs in Patients with Otomycosis

Background: Otomycosis is defined as a superficial fungal infection, accounting for about 10% of infectious otitis externa cases. Objectives: This study investigated patients with suspicious symptoms through the examination of their demographic information, isolate etiological agents, and in vitro antifungal susceptibility patterns. Methods: The samples of 170 patients with otitis externa symptoms were collected and confirmed for otomycosis by mycological examination (e.g., potassium hydroxide, methylene blue staining, and fungal culture) and molecular sequencing. In vitro antifungal susceptibility tests against miconazole, fluconazole, itraconazole, voriconazole, posaconazole, amphotericin B, and caspofungin were performed according to the Clinical and Laboratory Standards Institute (M27-A3/S4 and M38-A2). Results: Out of 170 patients, 145 subjects (85.29%) showed positive mycological findings. In this study, 55.8% of the patients were male, and the most common age group affected was 50 - 59 years (26.2%). Hearing loss and pruritus were the most common clinical manifestations. The most common occupation was being a housewife (47.5%), and most cases occurred during the winter (40%). Aspergillus niger was the most common species, followed by Aspergillus fumigatus, Candida albicans, and Candida glabrata. Caspofungin showed the highest activity against Aspergillus and Candida isolates; nevertheless, itraconazole demonstrated the lowest activity against Aspergillus isolates. Fluconazole showed the weakest power against Candida species. Conclusions: Due to climatic conditions, humidity, and dust, otomycosis has a high occurrence in Iran. Although otomycosis needs long-term antifungal therapy and recurrence is high in some cases, it is rarely life-threatening, and eardrop antifungals are usually enough to eradicate the infection. Local information about the antifungal pattern is useful for the control, prevention, and treatment of otomycosis.

Molecular characterization and antifungal activity against non-dermatophyte molds causing onychomycosis

Onychomycosis is a fungal disease that caused by different types of fungi. Non-dermatophyte molds are a large saprophytic fungi group that live in nature and could affect traumatic nails. The aim of this study was to identify non-dermatophyte molds causing onychomycosis and evaluation of several antifungal activities against the isolates. The samples consisted of 50 non-dermatophyte molds isolated from patients with onychomycosis confirmed by direct and culture examination fungal. DNA was extracted, amplified, and sequenced. Disk diffusion method was used to evaluate itraconazole, fluconazole, ketoconazole, terbinafine, posaconazole, and econazole activity against the isolates. The species identified as: Aspergillus flavus 22 (44%), A. niger 12 (24%), A. fumigates, 3 (6%), A. sydowii 3 (6%), A. terreus 1 (2%), Penicillium commune 2 (4%), P. glabrum 2 (4%), P. chrysogenum, 1 (2%), Fusarium solani 3 (6%) and F. thapsinum 1 (2%). Most of the samples were sensitive to terbinafine, itraconazole, and econazole and 94% of the isolates were resistant to fluconazole. This study showed that Aspergillus species were the most common cause of non-dermatophyte mold onychomycosis and fluconazole was the most resistant antifungals. Care must be taken to choose the appropriate antifungal drug for a better cure.

Nondermatophyte mould onychomycosis

Nondermatophyte moulds (NDMs) onychomycosis is often difficult to diagnose as NDMs have been considered contaminants of nails. There are several diagnostic methods used to identify NDMs, however, repeated laboratory isolation is recommended to validate pathogenicity. With NDM and mixed infection (dermatophytes plus NDM) onychomycosis on the rise, accurate clinical diagnosis along with mycological tests is recommended. Systemic antifungal agents such as itraconazole and terbinafine (e.g. pulse regimen: 1 pulse = every day for one week, followed by no treatment for three weeks) have shown efficacy in treating onychomycosis caused by various NDMs such as Aspergillus spp., Fusarium spp., Scopulariopsis brevicaulis, and Onychocola canadensis. Studies investigating topical therapy and devices for NDM onychomycosis are limited. The emergence of antifungal resistance necessitates the incorporation of antifungal susceptibility testing into diagnosis when possible, for the management of recalcitrant infections. Case studies documented in the literature show newer azoles such as posaconazole and voriconazole as sometimes effective in treating resistant NDM onychomycosis. Treatment with broad-spectrum antifungal agents (e.g. itraconazole and efinaconazole) and other combination therapy (oral + oral and/or oral + topical) may be considerations in the management of NDM onychomycosis.

Molecular Identification and Antifungal Susceptibility of Yeasts and Molds Isolated from Patients with Otomycosis

Fungal otitis externa, an infection of the external auditory canal caused by molds and yeasts, accounts for approximately 10-20% of ear canal infections accompanying high recurrence. The purpose of the current study was to assess the pattern of etiological agents of otomycosis and resistance profile as well as the rate of tympanic membrane perforation. A total of 1040 patients with symptoms of fungal otitis externa, in a period of two years, were investigated. The mycological tests revealed the presence of different fungi in 237 ears (22.8%). Fungal otitis was more related to filamentous fungi of the species Aspergillus flavus (54.43%), A. tubingensis (10.97%), and A. niger (8.86%), followed by yeasts, Candida orthopsilosis (7.59%), C. albicans (6.75%), and C. parapsilosis (5.06%). Tympanic membrane perforation rate was found to be 6.75% and was more common with otomycosis caused by A. flavus, A. tubingensis and C. albicans. In antifungal susceptibility tests, all tested drugs showed generally good activity against most isolates of molds and yeasts, while tolnaftate, clotrimazole, nystatin, and terbinafine had lowest effects. We found that among Aspergillus isolates, one A. niger isolate was resistant to voriconazole, and one A. flavus isolate was resistant to amphotericin B. Furthermore, among Candida species, three isolates of C. orthopsilosis showed high MIC values to fluconazole, two C. albicans isolates were considered fluconazole resistant and one isolate of C. parapsilosis was resistant to caspofungin and 3 isolates were resistant to fluconazole. Regarding the existence of the cases with perforated tympanic membrane and emerging species causing fungal otitis in the current report, the importance of the early physical examination, precise molecular identification, and the antifungal susceptibility evaluation is highlighted.

DNA sequencing, genomes and genetic markers of microbes on fruits and vegetables

The development of DNA sequencing technology has provided an effective method for studying foodborne and phytopathogenic microorganisms on fruits and vegetables (F & V). DNA sequencing has successfully proceeded through three generations, including the tens of operating platforms. These advances have significantly promoted microbial whole‐genome sequencing (WGS) and DNA polymorphism research. Based on genomic and regional polymorphisms, genetic markers have been widely obtained. These molecular markers are used as targets for PCR or chip analyses to detect microbes at the genetic level. Furthermore, metagenomic analyses conducted by sequencing the hypervariable regions of ribosomal DNA (rDNA) have revealed comprehensive microbial communities in various studies on F & V. This review highlights the basic principles of three generations of DNA sequencing, and summarizes the WGS studies of and available DNA markers for major bacterial foodborne pathogens and phytopathogenic fungi found on F & V. In addition, rDNA sequencing‐based bacterial and fungal metagenomics are summarized under three topics. These findings deepen the understanding of DNA sequencing and its application in studies of foodborne and phytopathogenic microbes and shed light on strategies for the monitoring of F & V microbes and quality control.

The Curious Case of "Case Report" of Infections Caused by Human and Animal Fungal Pathogens: An Educational Tool, an Online Archive, or a Format in Need of Retooling

Case reports describe the unusual occurrence and complications of diseases, diagnostic challenges, and notable therapeutic successes. Some journals have discontinued the case reports, while new case report journals have appeared in recent years. During the eightieth anniversary of Mycopathologia, it is fitting to examine the relevance of the case report since the journal continues to traverse the boundaries of basic and clinical sciences. A random sample of recent case reports and other articles were selected from Mycopathologia. Springer Nature individual article download statistics, and Google Scholar and Scopus citations numbers were compared to assess the reader access and bibliometric impact of case reports. Our analysis indicated that the case report format continues to be a vital element of publication in a cross-disciplinary journal such as Mycopathologia. Medical and veterinary case reports covering fungal pathogens are widely read as evident from their download numbers. The download numbers have a positive correlation with the completeness of the report, the topics and geographic origin of reports have a neutral influence, and the recency leads to lower downloads. There is no discernible trend between the download numbers and the citations of case reports as measured by Google Scholar and Scopus. A specially designed checklist for Mycopathologia case reports and new format MycopathologiaIMAGES are being introduced to improve the quality and relevance of case reports further.

Novel Point Mutations in cyp51A and cyp51B Genes Associated with Itraconazole and Posaconazole Resistance in Aspergillus clavatus Isolates

Aspergillus clavatus is a common environmental species known to cause occupational allergic disease in grain handlers. We have recently observed azole-resistant isolates of this fungus as a cause of onychomycosis. To further characterize the cause of resistance, the genes encoding 14 α-sterol demethylase enzyme (cyp51A and cyp51B) were characterized and analyzed in 9 ITC-susceptible isolates and 6 isolates with high minimum inhibitory concentrations (MICs) of clinical (nail and sputum) and environmental A. clavatus strains. We found that six isolates with itraconazole MIC >16 mg/L demonstrated nonsynonymous mutations, including V51I, L378P, E483K, and E506G, and synonymous mutations, including F53F, A186A, Q276Q, and H359H. Moreover, P486S was detected in five strains with ITR MIC >16 mg/L. One mutation, F324S, was detected in an isolate with posaconazole MIC >16 mg/L. The effect of E483K and P486S mutations of CYP51A on azole resistance was further investigated using homology modeling and molecular dynamics. We found that E483K and P486S mutations were located near the ligand access channel of CYP51A that could partly lead to narrowing the entry of the ligand access channels. Therefore, we concluded that E483K and P486S mutations may potentially contribute to the limited access of inhibitors to the binding pocket and therefore confer resistance to azole agents.

Low In Vitro Antifungal Activity of Tavaborole against Yeasts and Molds from Onychomycosis

The in vitro activity of tavaborole, an FDA-approved antifungal drug, was compared to that of four antifungal agents against 170 clinical fungal isolates originating from patients with onychomycosis. Tavaborole had low activity against all isolates compared to itraconazole, terbinafine, and fluconazole, the principal choices for treatment of onychomycosis. Thus, it appears that tavaborole is not a candidate for the treatment of onychomycosis due to Candida species, Aspergillus species, and dermatophytes.

Epidemiological survey of onychomycosis pathogens in Japan by real-time PCR

In Japan, an epidemiological survey of onychomycosis pathogens was performed using culture methods; however, the positive culture rate was 40% or less. As part of an epidemiological survey of dermatomycoses in Japan, we overcame this low positive rate by employing a real-time polymerase chain reaction (PCR) assay that allowed rapid and accurate detection and identification. In 2011, nail specimens were collected from patients at nine institutes in various prefectures in Japan and diagnosed as onychomycosis. For the detection and identification of the main pathogens causing onychomycosis, we performed real-time PCR using specific TaqMan® MGB probes and primer sets. Of the 496 onychomycosis samples, real-time PCR detected 382 cases (77.0%) caused by Trichophyton rubrum; 74 cases (15.0%) caused by Trichophyton interdigitale; and eight cases (1.6%) caused by Candida albicans. The real-time PCR positive rate was 96.2%. The most frequent pathogen was T. rubrum throughout life, with the number of patients affected peaking in the range of 60 to 69 years of age and no significant differences in the composition of causative pathogens by sex. We were able to detect and identify pathogens from almost all specimens and succeeded in analyzing the pathogens involved in onychomycosis cases in Japan. These data confirmed that our real-time PCR method was effective for detecting and identifying the main fungal pathogens from onychomycosis specimens.

Incidence and biodiversity of yeasts, dermatophytes and non-dermatophytes in superficial skin infections in Assiut, Egypt

OBJECTIVE

The aim was to identify the incidence of the causal agents from dermatophytes, non-dermatophytes and yeasts in Assiut Governorate employing, beside the morphological and physiological techniques, the genotypic ones.

PATIENTS

Samples from infected nails, skin and hair were taken from 125 patients.

MATERIALS AND METHODS

Patients who presented with onychomycosis, tinea capitis, tinea corporis, tinea cruris and tinea pedis during the period from February 2012 to October 2015 were clinically examined and diagnosed by dermatologists and were guided to Assiut University Mycological Centre for direct microscopic examination, culturing and identification.

RESULTS

Onychomycosis was the most common infecting (64.8% of the cases) followed by tinea capitis (17.6%). Direct microscopic preparations showed only 45 positive cases, while 96 cases showed positive cultures. Infections were more frequent in females than males. Fifty-one fungal species and 1 variety were obtained. Yeasts were the main agents being cultured from 46.02% of total cases. Non-dermatophytes were the second etiologic agents. Aspergillus was responsible for infecting 19.47% of total cases and dermatophytes appeared in only 15.93% of the cases.

CONCLUSIONS

Yeasts were the main causal agents followed by non-dermatophytic fungi (mainly species of Aspergillus, then Alternaria, Scopulariopsis and Fusarium). Both direct microscopic preparations and culturing are recommended for mycological evaluation of clinical specimens. Sequence analysis of ITS region is recommended for yeast identification.

The first report of onychomycosis caused by Cryptococcus friedmannii (Naganishia friedmannii) a basidiomycetous yeast

Yeasts are common etiologic agents of onychomycosis. This study reported a case of onychomycosis due to Cryptococcus friedmannii (Naganishia friedmannii). This yeast was isolated of the right great toenail of 57-year-old man. Microscopic examination of nail scrapings showed budding cells with thin capsule. Sequence analyzes of the internal transcribed spacer regions was closely related to Cryptococcus friedmannii. The results of susceptibility testing showed the Cryptococcus friedmannii to be sensitive to fluconazole, itraconazole and amphotericin B.