Otomycosis due to Filamentous Fungi

Abstract

Otomycosis is common throughout the world but barely studied in Spain. Our objective was to determine the microbiological and epidemiological characteristics of this pathology in Cadiz (Spain) between 2005 and 2010. Samples from patients with suspicion of otomycosis underwent a direct microscopic examination and culture on different media for fungi and bacteria. Mycological cultures were incubated at 30°C for at least seven days. Identification of fungi was based on colonial morphology and microscopic examination of fungal structure. From a total of 2,633 samples, microbial growth was present in 1,375 (52.2%) and fungal isolation in 390 (28.4%). We identified 228 yeasts and 184 filamentous fungi (13.4% of positive cultures and 47.2% of otomycosis), associated with yeasts in 22 cases (5.6%). The most frequent species were Aspergillus flavus (42.4%), A. niger (35.9%), A. fumigatus (12.5%), A. candidus (7.1%), A. terreus (1.6%), and Paecilomyces variotii (0.5%). Infection was predominant in men (54.9%) and patients beyond 55 years old (46.8%). The most common clinical symptoms were itching (98.9%), otalgia (59.3%), and hypoacusis (56.0%). Fall season reported the lowest number of cases (20.1%). Incidence of otomycosis and fungi producing otomycosis vary within the distinct geographical areas. In Cadiz, this infection is endemic due to warm temperatures, high humidity, sea bathing, and wind, which contributes to disseminate the conidia. Despite Aspergillus niger has been reported as the main causative agent, A. flavus is predominant in Cadiz. Although infection is usually detected in warm months, we observed a homogeneous occurrence of otomycosis in almost all the seasons.

Distribution of <i>Candida</i> Species and Molecular Typing of <i>C. albicans</i> Isolates in a Mexico City Tertiary Care Hospital from 2011 to 2013

“…Antifungal susceptibility analysis confirmed that resistance to AMB, FLU and ITR is an important characteristic of the HJM C. albicans isolates. Many studies have reported that resistant C. albicans and C. parapsilosis strains are rarely isolated [30] [31]; however, the rise in resistance against these important antifungal drugs has been increasingly associated with the use of these antifungal agents, resulting in the selection of specific resistant isolates. The widespread use of FLU as a prophylactic treatment and the preference for using AMB because of its relatively low cost, may promote the increase in the number of resistant isolates among these pathogens.…”

Filamentous Fungi

“…Other Aspergillus species, such as A. flavus, A. niger, A. nidulans, and A. terreus can also cause disease in humans (49)(50)(51)(52). These organisms can be readily identified in the laboratory based on the appearance of their asexual conidiophores, color of the colony front, which is a by-product of conidial pigmentation, and in combination with other features, such as arrangement of conidia around the vesicle and presence or absence of metulae (7).…”

A fungus in the haystack

“…otomycosis Otomycosis, or a fungal infection of the ear, can be caused by many different fungal varieties, most commonly of the Aspergillus or Candida genera. 3,4 Almost all patients with otomycosis present with pruritus of the ear; 4 otalgia, otorrhea, and hearing loss are also common symptoms. 3,4 In healthy patients, such fungal infections are generally superficial in nature, presenting with chronic otitis externa.…”

“…3,4 Almost all patients with otomycosis present with pruritus of the ear; 4 otalgia, otorrhea, and hearing loss are also common symptoms. 3,4 In healthy patients, such fungal infections are generally superficial in nature, presenting with chronic otitis externa. 4 In immunocompromised patients otomycosis can progress beyond the outer ear, causing perforation of the eardrum and in rare cases spread of infection to the middle ear or even to the meninges or mastoid process.…”