In vitro activities of fluconazole, itraconazole and voriconazole against otomycotic fungal pathogens

In Vitro Antifungal Activity of Luliconazole, Efinaconazole, and Nine Comparators Against Aspergillus and Candida Strains Isolated from Otomycosis

Background: Aspergillus and Candida species are the most commonly identified fungal pathogens in otomycosis. However, we usually encounter some difficulties in its treatment because many patients show resistance to antifungal agents and present a high recurrence rate. Objectives: The current research was conducted to compare the in vitro activities of luliconazole (LUL), and efinaconazole (EFN) and the nine comparators on Aspergillus and Candida strains isolated from otomycosis. Methods: The in vitro activities of nine common antifungal drugs (amphotericin B (AMB), voriconazole (VRC), fluconazole (FLU), itraconazole (ITC), ketoconazole (KTO), clotrimazole (CLO), nystatin (NYS), terbinafine (TRB), and caspofungin (CAS)) and two novel new azoles (LUL and EFN) against 108 clinical isolates of Aspergillus and Candida species obtained from otomycosis were assessed according to the CLSI broth microdilution document. Results: The LUL and EFN had the geometric mean minimum inhibitory concentrations (GM MICs) of 0.098 and 0.109 μg/mL against all Aspergillus strains, respectively. Furthermore, the GM MICs of all Candida isolates for LUL, EFN, CAS, CLO, VRC, AMB, ITC, KTO, FLU, NYS, and TRB were calculated to be 0.133, 0.144, 0.194, 0.219, 0.475, 0.537, 0.655, 1.277, 4.905, 9.372, and 13.592 μg/mL, respectively. Additionally, 6 (35.29%), 2 (11.7%), and 1 (5.88%) Candida isolates were resistant to FLU, CAS, and VRC, respectively. Conclusions: As the findings indicated, LUL and EFN showed the lowest GM MIC values against the examined species. Accordingly, these novel imidazole and triazole antifungal agents can be regarded as proper candidates for the treatment of otomycosis caused by Aspergillus and Candida strains.

Species identification and antifungal susceptibility testing of Aspergillus strains isolated from patients with otomycosis in northern China

BACKGROUND/PURPOSE

There are limited studies on species distribution and susceptibility profiles of Aspergillus strains isolated from patients with otomycosis in China.

METHODS

A total of 69 confirmed Aspergillus species isolates were obtained from ear swabs of patients diagnosed with otomycosis from 2017 to 2018 in northern China. Identification of these Aspergillus isolates at the species level was performed using conventional morphological methods and MALDI-TOF MS in combination with molecular sequencing, and in vitro susceptibility to nine antifungal agents was evaluated using the Sensititre YeastOne system.

RESULTS

The Aspergillus section Nigri had the greatest distribution of Aspergillus isolates. A. welwitschiae (n = 25) was the most predominant isolate in section Nigri, followed by A. tubingensis (n = 12) and A. niger (n = 11). Other Aspergillus species were also isolated, including A. terreus (n = 11), A. flavus/A. oryzae (n = 8), and A. fumigatus (n = 2). Amphotericin B, posaconazole, and echinocandins were highly in vitro active against all the isolates tested. 2.9% (2/69) of the isolates were resistant to azoles in our study, including one A. niger isolate with a high MIC value for itraconazole (ITR) (16 mg/L) and one A. tubingensis isolate cross-resistant to both voriconazole (VOR) (MIC >8 mg/L) and ITR (MIC >16 mg/L). One A. welwitschiae and one A. niger isolate both had increased MIC values of 4 mg/L against VOR.

CONCLUSIONS

A. welwitschiae was the most prevalent Aspergillus species isolated from patients with otomycosis. Our findings also indicated that the azole-resistant Aspergillus section Nigri should be utilized to guide clinical medication for Otomycosis.

Aspergillus flavus endocarditis and meningitis in a child with marfan syndrome

Background and Purpose:

Aspergillus species are implicated as the etiology of approximately 26% of endocarditis cases. Central nervous system aspergillosis is a life-threatening condition that has a mortality rate of 80%.

Case report:

Herein, we report a four– year- old female who was admitted to the pediatric infectious ward due to a fever of unknown origin in January 2020. She was a known case of Marfan syndrome with a family history of this syndrome in her mother. The species was identified using (PCR) and the antifungal susceptibility test was performed using four antifungal agents based on the Clinical and Laboratory Standards Institute M38 3rd edition. Fluconazole-resistant Aspergillus flavus was identified to be responsible for endocarditis and meningitis as well as fever of unknown origin.

Conclusion:

The clinicians should be aware and consider fungal endocarditis in blood culture-negative endocarditis even in patients with no significant risk factor when antibiotic therapy fails.

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.

Successful treatment of a recurrent Aspergillus niger otomycosis with local application of voriconazole

Fungal otitis (otomycosis) is a common infection encountered by otolaryngologists. Nevertheless, its management can be challenging because of its high recurrence rate and of the limited therapeutic options. A 45-year-old woman suffered from recurrent otomycosis. The ineffectiveness of successive antibiotic cures and repeated topical treatments with nystatin and then with econazole cream led to perform microbiological analyses. Culture of ear swab grew Aspergillus niger. The use of a 1% voriconazole sterile solution previously validated for treatment of eye infections was considered after ensuring the absence of known ototoxic effects of the antifungal and of the excipients. The patient was advised to apply locally this voriconazole solution daily for 14 days (3 drops, 3-4 times a day). Full recovery was obtained at the end of the treatment, and no relevant side effects were noticed. More than one year after completion of therapy, there was no recurrence. Our observation shows that voriconazole 1% solution is an interesting option for treating otomycosis which failed to respond to usual therapeutic options. Further prospective studies are now warranted to confirm these findings.

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.

Povidone iodine soaked gelfoam for the treatment of recalcitrant otomycosis - Our experiences at a tertiary care teaching hospital of eastern India

INTRODUCTION

Otomycosis is a common clinical condition seen in outpatient department of otorhinolaryngology. The treatment of the otomycosis is also very simple. However, sometime it is difficult to treat otomycosis along with mastoid cavity, chronic suppurative otitis media, immunocompromised patient, etc. with conventional treatment, called recalcitrant otomycosis. Here, we describe a technique of treatment for recalcitrant otomycosis.

MATERIALS AND METHODS

This is a prospective observational study/clinical trial carried out on 44 patients of recalcitrant otomycosis. They are divided into two groups, each of 22. One group treated with routine clotrimazole topical eardrops whereas other group treated with povidone iodine soaked gelfoam, placed in the external auditory canal.

RESULTS

There was no significance difference according to the age (P=0.134), gender (P=0.760) and causative agents (P=0.750) between treatment groups. The resolution of the symptoms showed statistically significant on itching (P=0.0001), otorrhoea (P=0.0033), fullness (P=0.0432) and earache (P=0.0259), whereas no statistical significant on hearing loss (P=0.0683), when treating with povidone iodine soaked gelfoam as compared to routine (clotrimazole) treatment. Resolution of signs like canal wall erythema (P=0.0045), tragal tenderness (P=0.0012) and congestion of tympanic membrane (P=0.0088) is statistically significant when comparing clotrimazole with povidone iodine. Apart from these, we did not reveal any adverse effects from the study populations treated with povidone iodine soaked gelfoam.

CONCLUSION

Use of the povidone iodine soaked gelfoam at the external auditory canal in recalcitrant otomycosis is an effective and well-tolerated treatment.

Assessment and management of chronic otitis externa

PURPOSE OF REVIEW

Chronic otitis externa (COE) remains a frustrating problem for both patient and physician. The end stage of disease, medial fibrosing otitis externa, is very challenging to repair. New and old therapies and promising approaches to the treatment of this often recalcitrant problem are presented in this review.

RECENT FINDINGS

Tacrolimus, a nonsteroidal immunosuppressant, and fluocinolone acetonide oil 0.01%, a medium-high potency steroid preparation, may offer additional therapeutic options in the struggle against this inflammatory ear canal/skin condition of often unknown cause. Relative potencies of many steroid preparations will be presented along with several treatment strategies for controlling COE. Underlying autoimmune problems such as Sjögren's disease, sarcoidosis, and amyloidosis must be searched and, if present, addressed and treated for resolution of symptoms. Cutting edge therapies, including use of bacteriophages and inflammatory proteases, will also be reviewed.

SUMMARY

No single therapy will be successful for every patient with COE. The search for an underlying cause, the removal of all possible irritants to the ear canal skin (e.g. Q-tips, water), debridement, and both topical and occasionally, systemic therapy will control (not cure …) the disease process in the vast majority of patients.