Clinical and microbial epidemiology of otomycosis in the city of Yasuj, southwest Iran, revealing Aspergillus tubingensis as the dominant causative agent

Sabz, Gholamabbas; Gharaghani, Maral; Mirhendi, Hossein; Ahmadi, Bahram; Gatee, Mohamad Amin; Sisakht, Marzie Taheripour; Hemati, Alireza; Mohammadi, Réza; Taghavi, Jabar; Nouripour‐Sisakht, Sadegh

doi:10.1099/jmm.0.000948

Cited by 27 publications

(25 citation statements)

References 34 publications

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“…Consistent with our results, Aspergillus is the most common pathogen in otomycosis ( van Diepeningen et al, 2015 ; Hagiwara et al, 2019 ; Sabz et al, 2019 ), while Malassezia is the dominant genus in the healthy individual ( Liu et al, 2020 ) in the literature. Very high abundance of Aspergillus (>80%) was detected in majority of samples in the pre-treatment group in the present study.…”

Section: Discussionsupporting

confidence: 91%

“…However, fungal communities in otomycosis may vary in different areas and in patients with or without underlying conditions. For example, according to studies in Iran ( Sabz et al, 2019 ; Kiakojuri et al, 2021 ), Aspergillus tubingensis (18/45 cases), not A. niger (6/45), is dominant in otomycosis in western China ( Zhang et al, 2020 ), while Aspergillus terreus is a dominant fungus in Hangzhou, a city in southeast China ( Zhang et al, 2021 ). In a coastal city in India, both A. niger and Aspergillus fumigatus are dominant ( Prasad et al, 2014 ).…”

Section: Introductionmentioning

confidence: 99%

“…The traditional methods could only identify the main pathogens in most cases ( Campbell et al, 2013 ). All of these limitations make it difficult to accurately identify fungal species by these methods ( Sabz et al, 2019 ). Compared to ITS sequencing, only 28.57% consistent results were obtained by culture ( Ren et al, 2020 ).…”

Section: Introductionmentioning

confidence: 99%

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Identification of the Fungal Community in Otomycosis by Internal Transcribed Spacer Sequencing

Cheng

Zhang

et al. 2022

Front. Microbiol.

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We used internal transcribed spacer (ITS) sequencing to identify the fungal community in otomycosis patients and to evaluate the treatment effects of bifonazole. Ten patients who visited the Department of Otolaryngology of Jiangsu Provincial Hospital on Integration of Chinese and Western Medicine from May 2020 to April 2021 were recruited. Otomycosis patients were treated with bifonazole solution once a day for 14 days. Samples collected from the external auditory canal before and after treatment (Pre-treatment, n = 14 ears; Post-treatment, n = 14 ears) were used for microscopic examination, fungal culture, and ITS sequencing. Samples collected from 10 volunteers (Control, n = 20 ears) were used as controls. The symptoms, including ear itching, aural fullness, otalgia, hearing loss, and physical signs were recorded before treatment as well as on the 7th and 14th days after treatment. Aspergillus was identified as a main pathogenic fungus by microscopic examination, fungal culture, and ITS sequencing. At the genus level, Aspergillus was more abundant in the pre-treatment group than the control and post-treatment groups, and Malassezia was more abundant in the control and post-treatment groups than the pre-treatment group. The fungal species richness and diversity reduced significantly in the pre-treatment group compared with the control and post-treatment groups. The effective rate of bifonazole was 64.29% and 100% on the 7th and 14th days after treatment, respectively. In conclusion, the results obtained from morphologic studies and ITS sequencing indicate that Aspergillus is the main pathogenic fungus of otomycosis patients in Nanjing, Jiangsu Province, China. Malassezia is the dominant resident fungi in healthy individuals. ITS sequencing provides comprehensive information about fungal community in otomycosis and is helpful in evaluating the efficacy of antifungal agents.

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Section: Discussionsupporting

confidence: 91%

Section: Introductionmentioning

confidence: 99%

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Identification of the Fungal Community in Otomycosis by Internal Transcribed Spacer Sequencing

Cheng

Zhang

et al. 2022

Front. Microbiol.

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“…3,4 When isolated in medical laboratories from non-sterile sites, such as respiratory specimens, the black aspergilli are often disregarded as a contaminant. 5,6 One notable exception is the external ear fungal infection, where black aspergilli are frequently reported in different geographical areas, such as Germany 7 , Hungary 8 , Turkey 9 , Iran 10,11 , Egypt 12 , Nigeria 13 , India 14 , Japan 15 , or China. 16 In both respiratory and external ear canal (EEC) specimens, the black aspergilli are rarely identified at the species level since no association with a specific clinical entity has been reported, in contrast with agriculture where the identification to the cryptic species is essential for deciphering between the different plant diseases, considering species-specific mycotoxin production.…”

Section: Introductionmentioning

confidence: 99%

Different repartition of the cryptic species of black aspergilli according to the anatomical sites in human infections, in a French University hospital

et al. 2021

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Black aspergilli of the section Nigri are rarely differentiated at the species level when originating from human specimens. We wondered whether some cryptic species could be more frequently observed in some clinical entities. We analyzed the 198 black isolates consecutively collected from the external ear canal (EEC; n = 66), respiratory specimens (n = 99), and environment (n = 33). DNA was extracted and species identification was performed upon the partial calmodulin gene. We identified by decreasing frequency: Aspergillus welwitschiae (35.3%), Aspergillus tubingensis (34.3%), Aspergillus niger (17.2%), Aspergillus luchuensis (4%), Aspergillus aff. welwitschiae (3%), Aspergillus neoniger (2%), Aspergillus piperis (1.5%), Aspergillus japonicus (1.0%), Aspergillus vadensis (0.5%), and two Aspergillus tubingensis clade (1%). The distribution of the three main cryptic species was different between EEC and respiratory samples (P < 0.001) but not different between respiratory and environment samples (P = 0.264). Aspergillus welwitschiae was more often associated with EEC (54.5%), whereas A. tubingensis and A. niger were predominant in respiratory samples (39.4 and 26.3%, respectively). Among the 99 respiratory isolates, only 10 were deemed responsible for probable invasive aspergillosis, of which six were mixed with other pathogenic moulds. This study shows the interest to pursue the identification of clinical isolates in the Aspergillus section Nigri to unravel some specific associations with clinical entities. The association of A. welwitschiae with otomycosis suggests a better fitness to infect/colonize the ear canal. Also, members of the Aspergillus section Nigri alone are rarely responsible for invasive aspergillosis. Lay summary We analyzed 198 black aspergilli isolates collected from different samples type to determine their species identification. We observe a different distribution of species between ear canal and respiratory samples (P < 0.001), suggesting a better fitness of A. welwitschiae to infect the ear canal.

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“…20,21 In this study, bilateral involvement was found in 1.3% cases, which is consistent with the findings of Sabz et al (2019) who observed bilaterality in 9% of the patients. 22 Otomycosis is mostly unilateral or associated with slight cases of bilateral otomycosis. This indicates that it is not a very contagious pathology without predilection for one side of the ear.…”

Section: Resultsmentioning

confidence: 99%

To study the prevalence & clino-mycological profile of Otomycosis in Saurashtra & Kutch region of Gujarat

Mistry¹,

Pathak²

2021

IJMMTD

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Background: Otomycosis is a superficial, sub-acute or chronic infection of the external auditory canal. It is worldwide in distribution with a higher prevalence in the hot, humid, and dusty areas of the tropics and subtropics. A wide variety of fungi can cause Otomycosis. Objectives: To determine the demographic profile & spectrum of fungi involved in Otomycosis in saurashtra & Kutch region of Gujarat. Materials and Methods : A retrospective study of 101 clinically suspected cases of otomycosis were conducted. The sample are taken by two sterile cotton swabs comprised of secretions, pus and debris from the external auditory canal. Direct microscopic examination by 10% KOH, Gram stain & cuiture on Sabouraud Dextrose Agar medium was done. Identification of fungi done by lacto phenol cotton blue, GERM TUBE TEST & growth on CORNMEAL AGAR and Hichrome Media ysed for species identification. Result: Out of 101 cases, 76(75.24%) were Culture Positive and 74(73.26%) were KOH positive. Out of 74 KOH positive, 65(87.83%) cases were culture positive. Predominantly males (52.6%) were affected. The most affected age group is 31-40 yrs of age (23.68%). Aspergillus niger (52.63%) was the predominant species isolated followed by Aspergillus flavus (36.84%), Candida spp, Penicillium spp. & Rhizopus spp. The disease is predominantly unilateral. Conclusion: Otomycosis should be suspected clinically and should be confirmed by laboratory diagnosis to prevent unnecessary use of antibiotics & there by antibiotic resistance. Mycological diagnosis is important to differentiated from bacterial infection, since symptoms (pruritus, otalgia, otorrhea and hypacusis) are not specific.

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Clinical and microbial epidemiology of otomycosis in the city of Yasuj, southwest Iran, revealing Aspergillus tubingensis as the dominant causative agent

Cited by 27 publications

References 34 publications

Identification of the Fungal Community in Otomycosis by Internal Transcribed Spacer Sequencing

Identification of the Fungal Community in Otomycosis by Internal Transcribed Spacer Sequencing

Different repartition of the cryptic species of black aspergilli according to the anatomical sites in human infections, in a French University hospital

To study the prevalence & clino-mycological profile of Otomycosis in Saurashtra & Kutch region of Gujarat

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