Otomycosis in the north of Iran: common pathogens and resistance to antifungal agents

Epidemiology and antifungal susceptibilities of clinically isolated Aspergillus species in South China

Aspergillosis is a rising concern worldwide; however, its prevalence is not well documented in China. This retrospective study determined Aspergillus's epidemiology and antifungal susceptibilities at Meizhou People's Hospital, South China. From 2017 to 2022, the demographic, clinical, and laboratory data about aspergillosis were collected from the hospital's records and analysed using descriptive statistics, chi-square test, and ANOVA. Of 474 aspergillosis cases, A. fumigatus (75.32%) was the most common, followed by A. niger (9.92%), A. flavus (8.86%), and A. terreus (5.91%). A 5.94-fold increase in aspergillosis occurred during the study duration, with the highest cases reported from the intensive care unit (52.74%) - chronic pulmonary aspergillosis (79.1%) and isolated from sputum (62.93%). Only 38 (8.02%) patients used immunosuppressant drugs, while gastroenteritis (5.7%), haematologic malignancy (4.22%), and cardiovascular disease (4.22%) were the most prevalent underlying illnesses. In A. fumigatus, the wild-type (WT) isolates against amphotericin B (99.1%) were higher than triazoles (97-98%), whereas, in non-fumigatus Aspergillus species, the triazole (95-100%) WT proportion was greater than amphotericin B (91-95%). Additionally, there were significantly fewer WT A. fumigatus isolates for itraconazole and posaconazole in outpatients than inpatients. These findings may aid in better understanding and management of aspergillosis in the region.

Aspergillus welwitschiae; a predominant otomycosis agent, new epidemiological and antifungal susceptibility data from Iran

BACKGROUND

Black aspergilli (section Nigri) are predominate etiologic agents of otomycosis, however, there is controversy in the exact differentiation of species. For several decades Aspergillus niger is considered the main otomycosis etiologic agent. Recently calmodulin gene has been accepted as a more suitable gene for the accurate assignment of Aspergillus species. Therefore, it is found that A. welwitschiae and A. tubingensis are the main otomycosis agents based on calmodulin gene sequencing.

AIMS

The objective of the study was to isolate and identify black aspergilli from otomycosis using the calmodulin gene and their susceptibility was evaluated against several antifungals.

METHODS

134 clinically confirmed patients with otomycosis were sampled and specimens were cultured on Sabouraud dextrose agar (SDA) at ambient temperature. Black aspergilli were screened based on colony morphology on SDA and microscopy features and then subjected to sequencing using calmodulin primers. Moreover, antifungal susceptibility for isolates was applied based on CLSI M38 3rd edition.

RESULTS

132 (98.5%) of patients had positive cultures for different species of molds or yeasts. Most of the patients (30.3%) ranged from 31 to 40 years, and 56.1% of them were female. Aspergillus section Nigri was the most prevalent fungal pathogen and of 86 isolates, 60.5% isolates were identified as A. welwitschiae, A. tubingensis, 31 (36.0%), A. niger (sensu stricto), 2 (2.3%), and A. neoniger 1 (1.2%). According to the maximum likelihood method, all isolates of A. tubingensis and one isolate of A. neoniger were included in the A. tubingensis clade. On the other hand, the clade of A. niger/A. welwitschiae contains, all isolates of A. welwitschiae, two A. niger (sensu stricto) isolates, and 36 isolates from other countries. Aspergillus welwitschiae was more sensitive to luliconazole, voriconazole, and amphotericin B compared to A. tubingensis. 78.8% of A. welwitschiae strains were classified as non-wild type to nystatin compared to 35.5% of A. tubingensis. Moreover, 3.2% of A. tubingensis strains were non-wild type against amphotericin B. The isolates of A. tubingensis were more sensitive to itraconazole than A. welwitschiae.

CONCLUSIONS

It is concluded that in contrast, to the previous study A. welwitschiae from section Nigri is the most causative agent of otomycosis followed by A. tubingensis. In addition, the isolates of A. welwitschiae were more sensitive to luliconazole, voriconazole, and amphotericin B compared to A. tubingensis. Whereas, the isolates of A. tubingensis were more sensitive to itraconazole than A. welwitschiae. On the other hand, 78.8% and 35.5% of A. welwitschiae and A. tubingensis strains were classified as a non-wild type against nystatin. Also, 3.2% of A. tubingensis strains were non-wild type against amphotericin B. All A. welwitschiae were included in the A. niger/A. welwitschiae clade, associated with different clinical and environmental species from different countries.

Otomycosis: The foremost aetiological agent causing otitis externa and the antifungal susceptibility pattern in North-Western Iran

BACKGROUND

Otomycosis is considered a recurring fungal ear infection. The external auditory canal provides an appropriate and optimal situation for fungal growth.

OBJECTIVES

The study aimed to identify the causative agents of otomycosis and determine corresponding antifungal drug susceptibility patterns in north-western Iran.

METHODS

From October 2020 until November 2021, 200 patients attended an otolaryngology referral centre with otitis externa, and their ear discharge and debris were examined and cultured. The identification of the fungal agents was implemented by polymerase chain reaction-restriction fragment length polymorphism and sequencing. In vitro antifungal susceptibility testing of the isolates was conducted in accordance with the CLSI broth microdilution protocols.

RESULTS

The prevalence of otomycosis was measured 50.5% (n = 101/200). The majority of patients were in their forties (n = 35, 34.6%) and female (n = 57, 56.4%), and the most prevalent symptom was otalgia (56.4%). The most underlying factor was remarked manipulation employing a cotton swab (65.3%). Regarding fungus, Aspergillus section Nigri (58.57%) was the foremost isolate, followed by Aspergillus section Flavi (19.23%) and Candida parapsilosis (14.96%). The predominance of Aspergillus isolates had minimal in vitro sensitivity to tioconazole and nystatin. Candida species represented higher geometric mean minimum inhibitory concentrations (MIC) against nystatin. The MIC of three Aspergillus species isolates shown above the epidemiologic cut-off values (ECV) against itraconazole.

CONCLUSIONS

Otomycosis incidence surpassed in comparison with the previous study as the most common cause of otitis externa. The MIC distribution of Aspergillus species isolates against triazole antifungals is close to the defined ECVs and likely outrun it over time.

Single Topical Application of 1% Clotrimazole Cream in Otomycosis

Aim: To assess the clinical improvement after single dose topical application of 1% clotrimazole cream in otomycosis and follow up for recurrence at the end of first and the third month. Materials and Methods: A prospective observational study was carried out at Government Medical college hospital. Patients with KOH diagnosed fungal infection of external auditory canal were included in the study. After obtaining informed written consent from the participating patients, a detail clinical history was taken. Single topical application of 1% clotrimazole cream in otomycosis. The fungal debris was removed with the help of suction aspiration and dry mopping. A single topical application of 1% clotrimazole cream was applied under all aseptic precautions. On the 3rd day the applied cream was cleaned with help of suction under ear microscope. Patients were advised to follow up after one month and three months. During each follow up patients were assessed clinically and examined for residual fungal debris. Result: Otomycosis was seen predominantly in middle aged females, housewives and laborers by occupation. Earache was most common symptom seen in 65.2%. Unilateral involvement was seen in 89.3% cases. The most common organism isolated in otomycosis was Aspergillus niger. At the end of one month of treatment with a single dose of 1% clotrimazole cream, 102 (91.0%) patients were recovered and 10 (9.0%) patients were with persistence or recurrence of the symptoms. At the end of third month, the recovery rate was 84.8% and recurrence rate was 6.3%. Conclusion: Single topical application of 1% clotrimazole cream is effective in treating otomycosis.

In Vitro Combination of Terbinafine with Ketoconazole Against Aspergillus Species with Terbinafine High MIC Values Isolated From Otomycosis

Otomycosis is a common mycotic infection of the external auditory canal, and Aspergillus species are one of the most frequent causative agents worldwide. The limited antifungal arsenal, the high toxicity and side effects of antifungal agents, and the growing resistance to the currently available antifungals underscore the need for new therapeutic strategies. The present study aimed to evaluate the combined in vitro efficacy of terbinafine and ketoconazole against Aspergillus species with terbinafine high MIC values isolated from patients with otomycosis.84 Aspergillus species with high MIC values to terbinafine (≥ 4 µg/ml), consisting of A. flavus, A. tubingensis, A. niger, and A. terreus, were included in this study. The checkerboard microdilution method evaluated the in vitro interactions using the CLSI reference technique. Synergistic effects were observed for 66.67% (56/84) of all isolates (FICI ranging from 0.19 to 0.5). However, the interactions of terbinafine and ketoconazole exhibited indifference in 33.33% (28/84) of the isolates, and no antagonism was observed for any combination. The interaction of terbinafine and ketoconazole showed synergistic activity against Aspergillus species with high MIC values, suggesting that this is an alternative and promising approach for treating otomycosis.

Otomycosis caused by the cryptic and emerging species Aspergillus sydowii: two case reports

Two cases of otomycosis have been reported in patients undergoing tympanomastoidectomy. The first one had chronic otitis media, hypertrophic concha and nasal septum deviation, tympanic perforation and otorrhea. The second had otalgia, pruritus, chronic otitis media and cholesteatoma. Direct examination showed mycelial septate filaments with a branch at an angle close to 45°, later identified as Aspergillus sydowii by sequencing the BenA and CaM genes. Susceptibility testing showed low MIC of amphotericin B, itraconazole, ketoconazole and ciclopirox olamine. In both cases, ketoconazole was instituted for 10 days. Otomycosis is a challenge as it is primarily recurrent in patients undergoing surgery. The clinical implication, the identification of the emerging pathogen and the determination of MIC were necessary for the knowledge of the epidemiological profile and establishment of the treatment.

Antifungal Effect of Nanoparticles against COVID-19 Linked Black Fungus: A Perspective on Biomedical Applications

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a highly transmissible and pathogenic coronavirus that has caused a 'coronavirus disease 2019' (COVID-19) pandemic in multiple waves, which threatens human health and public safety. During this pandemic, some patients with COVID-19 acquired secondary infections, such as mucormycosis, also known as black fungus disease. Mucormycosis is a serious, acute, and deadly fungal infection caused by Mucorales-related fungal species, and it spreads rapidly. Hence, prompt diagnosis and treatment are necessary to avoid high mortality and morbidity rates. Major risk factors for this disease include uncontrolled diabetes mellitus and immunosuppression that can also facilitate increases in mucormycosis infections. The extensive use of steroids to prevent the worsening of COVID-19 can lead to black fungus infection. Generally, antifungal agents dedicated to medical applications must be biocompatible, non-toxic, easily soluble, efficient, and hypoallergenic. They should also provide long-term protection against fungal growth. COVID-19-related black fungus infection causes a severe increase in fatalities. Therefore, there is a strong need for the development of novel and efficient antimicrobial agents. Recently, nanoparticle-containing products available in the market have been used as antimicrobial agents to prevent bacterial growth, but little is known about their efficacy with respect to preventing fungal growth, especially black fungus. The present review focuses on the effect of various types of metal nanoparticles, specifically those containing silver, zinc oxide, gold, copper, titanium, magnetic, iron, and carbon, on the growth of various types of fungi. We particularly focused on how these nanoparticles can impact the growth of black fungus. We also discussed black fungus co-infection in the context of the global COVID-19 outbreak, and management and guidelines to help control COVID-19-associated black fungus infection. Finally, this review aimed to elucidate the relationship between COVID-19 and mucormycosis.

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.

Treatment of otomycosis with clotrimazole: results accordingly with the fungus isolated

BACKGROUND

Otomycosis is usually caused by Candida spp or Aspergillus spp. While Candida is usually multissensitive to available antifungals, Aspergillus is not. Topical antifungals for otomycosis that are available in Portugal are scarce, and systemic treatments have too many interactions and contraindications.

OBJECTIVES

Determine otomycosis epidemiology, microbiology and treatment results.

METHODS

Observational study that included patients followed in Professor Doutor Fernando Fonseca Hospital, between 2011 and 2020. Otomycosis diagnosis was obtained through ear drainage culture, and every case was treated with 1% clotrimazole ear drops plus ear cleaning once per week.

RESULTS

Aspergillus was found in ear drainage culture in 43.9% of patients and Candida in the remaining. There was a significant statistical difference between patients with otomycosis caused by Aspergillus versus Candida in treatment duration from 25.0 days (16.5-43.0) versus 14.0 days (7.0-18.5) (p < .001), respectively.

CONCLUSIONS

Otomycosis was more frequently caused by Candida, and this type of otomycosis is treated faster with clotrimazole 10 mg/dL plus ear cleaning, when compared with otomycosis by Aspergillus.

SIGNIFICANCE

If otomycosis causative agent is identified or suspected, a prediction of the time needed till the resolution of otomycosis can be made, when clotrimazole ear drops are used.

Otomycosis in the South of Iran with a High Prevalence of Tympanic Membrane Perforation: A Hospital-Based Study

INTRODUCTION

Otomycosis is a superficial infection of the external ear caused by fungal pathogens. The genera Aspergillus and Candida are considered the main fungal causative agents, with the predominance of Aspergillus section Nigri. The present study aimed to evaluate the clinical symptoms of patients with otomycosis and predisposing factors and to identify fungal etiological agents using molecular approaches. We also present an overview of published papers on tympanic membrane perforation (TMP) secondary to otomycosis.

MATERIALS AND METHODS

An otorhinolaryngologist collected specimens from external ear canals of patients with suspected otomycosis based on the patient's history and clinical examinations. The specimens were collected using sterile swabs. Fungal isolates were confirmed in clinical specimens by direct microscopy and culture methods. Fungal isolates were identified based on molecular approaches.

RESULTS

In total, specimens from 211 patients with suspected otomycosis were examined. The presence of fungi was confirmed in about 51% of patients based on fungal elements in direct microscopy and culture-positive fungi. Aspergillus tubingensis was the most commonly isolated species (52.77%), followed by Aspergillus niger (25.92%). Otomycosis due to infection with Candida species was observed in 16% of cases. Of note, in 36.11% of cases, otomycosis was associated with TMP.

CONCLUSION

A mycological examination is indispensable for a correct diagnosis in patients with otitis extern. TMP should be considered in patients with otomycosis, as it appears to be relatively common in this population.

A Comparison of Antifungal Drugs and Traditional Antiseptic Medication for Otomycosis Treatment: A Systematic Review and Meta-Analysis

Objectives/Hypothesis: To perform a systematic review and meta-analysis to compare the efficacy of and complications associated with antifungal drugs and traditional antiseptic medication for the treatment of otomycosis.

Data Sources: The PubMed, EMBASE, GeenMedical, Cochrane Library, CBM, CNKI, VIP and other databases were searched from January 1991 to January 2021.

Methods: The systematic literature review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Randomized controlled trials (RCTs) and non-randomized studies (case-control, cohort, and case series) were included to assess the topical use of antifungal drugs and traditional antiseptic medication in patients with otomycosis. The research subjects were patients who were clinically diagnosed with otomycosis and whose external auditory canal secretions were positive for fungi. Funnel plots were used to detect bias, and the Q test was used to assess heterogeneity. The random-effects model was used for meta-analysis. The t-test was used to assess significance.

Results: Of the 324 non-duplicate studies screened, 16 studies met the criteria for full-text review, and 7 were included in the meta-analysis. Four studies reported recovery conditions (P = 0.01). Six common complications after medication use were compared, and there were no significant differences. The authors further conducted subgroup analysis according to complications. The differences in the rates of ear distension (P = 0.007), earache (P = 0.03) and tinnitus (P = 0.003) were statistically significant.

Conclusion: The results of this meta-analysis and literature review showed that antifungal drugs and traditional antiseptic medication were effective in relieving symptoms in patients with otomycosis, and the two treatments were associated with different complications. Otolaryngologists have the option to use one medication or a combination of two drugs on the basis of the condition. Future research in this area should include RCTs with long-term follow-up to guide the development of otomycosis guidelines to overcome some of the weaknesses found in the literature.

Systematic Review Registration:https://www.crd.york.ac.uk/PROSPERO/#myprospero.

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.

Tympanic membrane perforation secondary to Aspergillus niger otomycosis

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Aspergillus is a fungal mold, which is ubiquitous in nature.

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Aspergillosis results in significant morbidity and mortality worldwide.

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A rare case of tympanic membrane perforation secondary to Aspergillus niger otomycosis was reported.

Aspergillus niger is one of more than 340 different species belonging to the filamentous fungal genus Aspergillus. Aspergillosis can present with a wide range of clinical syndromes, and it results in significant morbidity and mortality worldwide. Here we described a rare case of the left central tympanic membrane perforation secondary to Aspergillus niger otomycosis. The patient underwent tympanoplasty with good improvement.

Antifungal susceptibility profiles of otomycosis etiological agents in Ahvaz, Iran

Background and Purpose

Otomycosis is a secondary ear fungal infection among predisposed individuals in humid conditions. Aspergillus species are the most common etiologic agents of this infection. Several ototopical antifungals are currently used for the treatment of this disease; however, recurrence and treatment failure are usually observed in some cases. Regarding this, the present study was conducted to investigate the antifungal activity of caspofungin, azoles, and terbinafine against the isolated agents of otomycosis.

Materials and Methods

This study was conducted on the specimens collected from 90 patients with otomycosis. The samples were cultured on Sabouraud dextrose agar and identified based on morphological characteristics, physiological tests, and microscopic features. Furthermore, the microdilution method was used for antifungal susceptibility testing according to the Clinical and Laboratory Standards Institute (CLSI) guidelines. Finally, the minimum inhibitory concentration (MIC) and minimum effective concentration (MEC) ranges, MIC/MEC₅₀, MIC/MEC₉₀, and geometric mean (GM) MIC/MEC were calculated for the isolates.

Results

According to the results, 77 patients with otomycosis were positive for different Aspergillus (88.3%) and Candida (11.7%) species. Aspergillus niger complex (n=36) was found to be the most common agent, followed by A. flavus, A. terreus, and A. nidulans complexes. Furthermore, epidemiological cutoff values (ECVs) were lower than those presented by the CLSI for itraconazole and caspofungin in 98.5% and 42.6% of Aspergillus species, respectively. Terbinafine exhibited a great activity against Aspergillus species, while fluconazole revealed a low activity against both Aspergillus species. Based on the results, 77.8% of Candida species were resistant to caspofungin; however, miconazole and econazole had low MIC ranges.

Conclusion

Aspergillus niger and A. flavus complexes were identified as the most common agents accounting for 85.7% of the isolates. In addition, terbinafine was identified as the best antifungal for both Aspergillus and Candida species. Moreover, tested azoles had relatively low MICs, whereas most of the isolates had the MIC values beyond the caspofungin ECVs.

Otomycosis Due to the Rare Fungi Talaromyces purpurogenus, Naganishia albida and Filobasidium magnum

Otomycosis is a common finding in otorhinolaryngology clinics and is usually caused by species of Candida and Aspergillus, particularly black aspergilli. Meanwhile, other fungi can give rise to this infection, and the identification of these requires accurate methods. Here, we report three cases of otomycosis due to rare fungal pathogens. All the patients were young females, and manipulation of the ear canal was identified as a common potentially predisposing factor. In direct examination, filamentous fungal elements (in one case) and yeast cells (in two other cases) were seen. Culture was positive in all cases. Based on PCR-sequencing of internal transcribed spacers and β-tubulin (for mold isolate), the isolated fungi were identified as Talaromyces purpurogenus, Naganishia albida and Filobasidium magnum. By susceptibility testing of the isolates to fluconazole, itraconazole, voriconazole and amphotericin B, the lowest minimum inhibitory concentration values were observed for amphotericin B followed by voriconazole. Patients were successfully treated by a combination of antifungals and corticosteroids with no relapse over the next year, except for the case due to F. magnum, in which, despite partial recovery, a course of relapse was reported in the 1-year follow-up call.

Role of Clotrimazole in Prevention of Recurrent Otomycosis

Otomycosis is one of the relatively common diseases in the world which is caused by different fungi especially saprophytes. Concerning the relapse of this disease in a number of individuals, the present study was performed to evaluate the inhibitory effect of clotrimazole drop in the relapse of otomycosis. Clinical samples were taken by an ENT specialist from patients suspicious of having otomycosis. A part of these samples were stained, and others were cultured. The diagnosis of otomycosis was made on the basis of the recognizable and characteristic appearance of fungal hyphae or mycelium and fruiting bodies and/or conidiophores under microscopic examination. Patients with suspected otomycosis are not at risk of recurrence after treatment with clotrimazole drops. Out of the 161 individuals in whom definite diagnosis of otomycosis was made, the most affected individuals were, in the age range of 40–49 years, women, urban citizens, and housewives. Pruritus and diminished hearing were the main complaints of the patients. Aspergillus niger and A. flavus as well as Candida albicans were the main causes of the disease. The relapse of disease was observed in only five patients (3.1%), where A. niger was the main fungus. Most relapses were observed in women and in those with diminished hearing, manipulating the ears, ulcers in the canal, and tympanum. Our results suggested that usage of clotrimazole can be effective in reducing the relapse of otomycosis, and concerning the high cost of treating otomycosis while the low cost of using clotrimazole, usage of this drop is recommended to reduce the relapse of otomycosis.

Molecular epidemiology of otomycosis in Isfahan revealed a large diversity in causative agents

PURPOSE

To elucidate the clinical and microbial epidemiology of otomycosis in Isfahan, Iran.

METHODOLOGY

From January 2016 to January 2017 all patients clinically suspected of otomycosis at Al-Zahra Hospital, Isfahan, Iran were recruited. Specimens were taken using sterile swabs by an otorhinolaryngologist and subjected to culture and microscopy using potassium hydroxide and Giemsa stain. Isolated fungi were identified based on morphological and molecular characteristics.

RESULTS

Otomycosis was confirmed in 97/120 patients (80.8 %). Females (72.2 %) and patients aged 30-39 years (33 %) were more commonly affected than others. Manipulation of ear canal (62.9 %) was the most common predisposing factor. Pruritus was observed in 84.54  % of the patients followed by hearing impairment (81.4 %), and most episodes were detected over the summer (50.5 %). Culture was positive for 81 (83.5  %) of confirmed cases and molds were the most prevalent causative agents (n=51, 63 %) followed by yeasts (n=19, 23.4 %) and yeast/mold mixes (n=11, 13.6 %). For the 16 remaining patients, no growth was seen in culture despite a positive result on direct examination. In total, 92 isolates (63 molds and 29 yeasts) were recovered in culture. Application of molecular methods showed 18 fungal species and the vast majority of them belonged to Aspergillus (n=53, 57.6 %) and Candida genus. Among the species involved, Candida parapsilosis (n=22, 22.7 %) and Aspergillus tubingensis (n=15, 15.5 %) were the most encountered species.

CONCLUSION

Outcomes from this study showed a different picture of prevalence, where C. parapsilosis and A. tubingensis but not Aspergillus niger were the most species encountered from patients suffering from otomycosis.

Outer Ear Infections in Iran: A Review

BACKGROUND:

Otitis externa is the fungal and bacterial infection of the outer ear.

AIM:

We aimed to investigate the published papers about the outer ear infections in Iran and suggest standardised investigations and treatments.

METHODS:

We used different electronic databases like PubMed, Scopus, Web of Science, Iranmedex, Google Scholar, and Magiran with specific keywords.

RESULTS:

We obtained forty published full-text articles for review of data. Our results indicated the women were more infected than men. The ages of patients were < 1-81 years. As clinically symptoms, itching and Feel the ear fairy were the most common presenting complaints in most cases. Most infections were the pure bacterial and fungal origin, respectively. However, some of the studies were mixed fungal-bacterial infections — Pseudomonas spp. And Aspergillus niger were the most common bacteria and fungi isolates respectively in Iranian patents.

CONCLUSION:

Fungal and bacterial specific cultures may be recommended, and anti-fungal drugs may be added, to treatment regimens in patients with otitis externa to reduce the clinical symptoms.

Effect of combination therapy with ceftizoxime and clotrimazole in the treatment of otomycosis

Background and Purpose:

There are controversial findings regarding the efficacy of antifungal drugs in the treatment of a ruptured eardrum following fungal infections. Regarding this, the aim of the present study was to evaluate the therapeutic effect of the co-administration of antifungal and antibacterial agents in the treatment of otomycosis with tympanic membrane perforation.

Materials and Methods:

This analytical, clinical trial was conducted on 87 patients with otomycosis showing no bacterial elements in the direct observation and culture. The study population was assigned into two groups of intervention (n=45) and control (n=42). The demographic and clinical data, as well as the data related to the direct observation and culture of the ear samples were recorded in a checklist. All statistical analysis was performed in SPSS (version 24).

Results:

The most prevalent symptoms in both groups were hearing loss and itching, and the most common finding was secretion. Aspergillus and Candida were the most frequent fungi isolated from the samples. After the implementation of combination therapy, the intervention group demonstrated a significant decrease in symptoms and signs, compared to the control group (P=0.005).

Conclusion:

The findings of the present study indicated that the use combination therapy with ceftizoxime powder and clotrimazole ointment was effective the in treatment of the patients with tympanic membrane rupture showing no bacterial effects in direct examination and culture.

Species identification and in vitro antifungal susceptibility testing of Aspergillus section Nigri strains isolated from otomycosis patients

INTRODUCTION

Aspergillus niger is the most commonly reported etiology of otomycosis based on morphological characteristics. This fungus is a member of Aspergillus section Nigri, a set of morphologically indistinguishable species that can harbor various antifungal susceptibility patterns. The aim of this study was to accurately identify and determine the susceptibility pattern of a set of black aspergilli isolated from otomycosis patients.

METHODS

Forty-three black Aspergillus isolates from otomycosis patients were identified by using the PCR-sequencing of the β-tubulin gene. Furthermore, the susceptibility of isolates to three antifungal drugs, including fluconazole (FLU), clotrimazole (CLT) and nystatin (NS), were tested according to CLSI M38-A2. The data were analyzed using the SPSS software (version 15).

RESULTS

The majority of isolates were identified as A. tubingensis (32/43, 74.42%) followed by A. niger (11/43, 25.58%). The lowest minimum inhibitory concentration (MIC) values were observed for NS with geometric means (GM) of 4.65μg/mL and 4.83μg/mL against A. tubingensis and A. niger isolates, respectively. CLT showed wide MIC ranges and a statistically significant inter-species difference was observed between A. tubingensis and A. niger isolates (P<0.05). FLU was inactive against both species with GMs>64μg/mL.

CONCLUSION

Species other than A. niger can be more frequent as observed in our study. In addition, considering the low and variable activity of tested antifungal drugs, empirical treatment can result in treatment failure. Accurate identification and antifungal susceptibility testing of isolates is, however, recommended.

Epidemiology of dermatomycoses in Kerman province, southeast of Iran: A 10-years retrospective study (2004-2014)

OBJECTIVES

Superficial and cutaneous fungal infections (SCFIs) are an important public health problem and are common in tropical and subtropical countries. Pityriasis versicolor, dermatophytosis, erythrasma, onychomycosis, and otomycosis are the major diseases associated with SCFIs. The aim of this study was to evaluate the prevalence and causative agents of dermatomycoses over a period of 10 years in Kerman province, southeast of Iran.

METHODS

A number of 1782 subjects, including 1096 females and 686 males, with cutaneous disorders in their skin, nail, and hair suspected to have SCFIs participated in this study. The collected specimens were examined using direct microscopy examination, staining, culture on specific media and PCR-RFLP technique.

RESULTS

In total, 617 (34.62%) subjects had SCFIs, of whom 290 (47%) were female and 327 (53%) were male. Identified SCFIs included yeast infections, dermatophytosis, saprophyte onychomycosis, erythrasma, and otomycosis due to non-dermatophytic molds (NDMs). The highest prevalence of dermatomycoses was found among the 41-50-year and 31-40-year age groups. Tinea unguium was the most common clinical pattern of dermatomycoses, and T. mentagrophytes was the predominant agent. Also, Aspergillus spp. were the most common NDMs agents of onychomycosis and otomycosis.

CONCLUSIONS

This study summarized the epidemiological trends and etiologic agents of SCFIs in a 10-year period in Kerman, southeast of Iran. Consideration of the current epidemiologic trends in the prevalence and knowledge of the exact causative agents of SCFIs may play an important key role towards further investigations, diagnosis, and modification of current treatments.

Biochemical and biophysical combined study of bicarinalin, an ant venom antimicrobial peptide

We have recently characterized bicarinalin as the most abundant peptide from the venom of the ant Tetramorium bicarinatum. This antimicrobial peptide is active against Staphylococcus and Enterobacteriaceae. To further investigate the antimicrobial properties of this cationic and cysteine-free peptide, we have studied its antibacterial, antifungal and antiparasitic activities on a large array of microorganisms. Bicarinalin was active against fifteen microorganisms with minimal inhibitory concentrations ranging from 2 and 25μmolL(-1). Cronobacter sakazakii, Salmonella enterica, Candida albicans, Aspergilus niger and Saccharomyces cerevisiae were particularly susceptible to this novel antimicrobial peptide. Resistant strains of Staphylococcus aureus, Pseudomonas aeruginosa and C. albicans were as susceptible as the canonical strains. Interestingly, bicarinalin was also active against the parasite Leishmania infantum with a minimal inhibitory concentrations of 2μmolL(-1). The bicarinalin pre-propeptide cDNA sequence has been determined using a combination of degenerated primers with RACE PCR strategy. Interestingly, the N-terminal domain of bicarinalin pre-propeptide exhibited sequence similarity with the pilosulin antimicrobial peptide family previously described in the Myrmecia venoms. Moreover, using SYTOX green uptake assay, we showed that, for all the tested microorganisms, bicarinalin acted through a membrane permeabilization mechanism. Two dimensional-NMR experiments showed that bicarinalin displayed a 10 residue-long α-helical structure flanked by two N- and C-terminal disordered regions. This partially amphipathic helix may explain the membrane permeabilization mechanism of bicarinalin observed in this study. Finally, therapeutic value of bicarinalin was highlighted by its low cytotoxicity against human lymphocytes at bactericidal concentrations and its long half-life in human serum which was around 15h.

Otomycosis in Adolescent Patients Referred to the Therapeutic Centers in Babol City, Iran

Background:

Otomycosis is an external ear canal infection caused by various fungi. This disease is prevalent in some tropical and subtropical regions or countries.

Objectives:

Given the crucial role of fungal agents in the treatment of the disease, the aim of the present study was to identify the fungi in ear canal of patients with otomycosis admitted to the hospitals in Babol City, Iran.

Patients and Methods:

This study included 56 patients with otomycosis. After removal of ear infectious samples, some of them were placed on the slides for direct examination and also a portion of them was plated on the Sabouraud dextrose agar with chloramphenicol for fungal growth. The slides were studied for the presence of fungal elements. Conventional methods were performed to determine fungal colonies.

Results:

Thirty-three patients (55.36%) were female and the rest were male. Fungal elements were observed in 11 cases (19.64%) in the direct examination, alone, and 45 specimens (80.36%) had fungi and bacteria combined. Septate mycelia, with 43 cases, had the most frequent fungal elements in direct examination. Aspergillus and Candida genera were the prevalent fungal colonies in culture media.

Conclusions:

According to the role of different genera of fungi in the process of otomycosis, much attention on the macroscopic and microscopic examination of the samples leads to special treatment decisions of a physician.

Otomycosis in iran: a review

Fungal infection of the external auditory canal (otitis externa and otomycosis) is a chronic, acute, or subacute superficial mycotic infection that rarely involves middle ear. Otomycosis (swimmer's ear) is usually unilateral infection and affects more females than males. The infection is usually symptomatic and main symptoms are pruritus, otalgia, aural fullness, hearing impairment, otorrhea, and tinnitus. Fungal species such as yeasts, molds, dermatophytes, and Malassezia species are agents for otitis externa. Among molds, Aspergillus niger was described as the most common agent in the literature. Candida albicans was more prevalent than other yeast species. Otomycosis has a worldwide distribution, but the prevalence of infection is related to the geographical location, areas with tropical and subtropical climate showing higher prevalence rates. Otomycosis is a secondary infection and is more prevalent among swimmers. As a result, a higher incidence is reported in summer season, when more people interested in swimming. Incidence of otomycosis in our review ranged from 5.7 to 81 %, with a mean value of 51.3 %. Our results showed that 78.59 % of otomycosis agents were Aspergillus, 16.76 % were Candida species, and the rest (4.65 %) were other saprophytic fungi. Among Iranian patients, incidence of infection was highest in summer, followed by autumn, winter, and spring. In Iran, otomycosis was most prevalent at the age of 20-40 years and the lowest prevalence was associated with being <10 years old. The sex ratio of otomycosis in our study was (M/F) 1:1.53.

Lamisil, a potent alternative antifungal drug for otomycosis

Background and Purpose:

Otomycosis is an acute, subacute or chronic fungal infection of the pinna, the external auditory meatus and the ear canal caused mainly by several species of saprophytic fungi. Lamisil (Terbinafine) is an allylamine antifungal agent, that is used both in the topical and oral administration for the treatment of dermatophytosis, cutaneous candidiasis, and the pityriasis versicolor. We investigated the in vitro activity of clotrimazole, miconazole, nystatin, and Lamisil against the agents of otomycosis.

Materials and Methods:

Fifteen clinically obtained isolates from otomycosis (Aspergillus species; n=13, and Candida species, n=2) and 8 environmental isolates of Aspergillus were tested. The disk diffusion method was employed to detect susceptibility. In the present study, the in vitro activity of the terbinafine with clotrimazole, miconazole, and nystatin against several isolates of Aspergillus and Candida with different sources were compared.

Results:

Out of 23 isolates of Aspergillus, Candida 4(17.4%) and 1(4.4%) were resistant to nystatin and miconazole, respectively. In addition, all tested organisms were sensitive to clotrimazole and terbinafine. Statistical analysis has shown that there are no significant differences on the effects of clotrimazole, miconazole and, terbinafine on saprophytic (environmental) and pathogenic isolates of A. niger, A. flavus, and A. terreus (P value= 0.85). In addition, all tested organisms were found to be highly susceptible to terbinafine (P< 0.04).

Conclusion:

This is a new approach for the possible use of Lamisil for the treatment of otomycosis.