Frequency of occurrence, seasonal variation and antifungal susceptibility of opportunistic Mucorales isolated from hospital soils in Iran

Abstract

Background Mucorales are opportunistic pathogens that can cause life‐threatening diseases predominantly in immunocompromised patients. Objectives This study aimed to investigate the frequency, seasonal variation and antifungal susceptibility of pathogenic Mucorales in the soil collected from seven hospitals in Urmia, Iran, between November 2017 and July 2018 in four different seasons. Methods Mucorales isolates obtained from soil were characterised based on conventional and molecular assays. In addition, in vitro antifungal susceptibility was performed using the CLSI M38Ed3 procedure. Results Out of 196 tested soil samples, 80 (40.8%) samples were positive for mucoralean fungi. Rhizopus arrhizus var. arrhizus (n = 47) was the most frequent species followed by Mucor circinelloides (n = 21) and Cunninghamella echinulata (n = 6). A seasonal variation in the frequency of Mucorales in soil was detected with a maximum of culture‐positive soil samples detected in wet autumn (43.2%) followed by winter (23.4%), summer (19.7%) and spring (13.6%). In vitro antifungal susceptibility testing for 80 environmental isolates exhibited MIC of ≤2 μg/ml for amphotericin B indicating the smallest range of MIC variation among the tested Mucorales (range: 0.125–2 μg/ml). Among the azoles, posaconazole was the most effective antifungals (GM MIC, 0.724 μg/ml). Conclusions We considered associations of species and seasonal frequencies between soil mucoralean fungi and mucormycosis. The effect of opportunistic Mucorales dominating in the soil and prevalent causative agents of mucormycosis in Iran reported in the literatures but more comprehensive studies are needed to confirm this conclusion.

Utility of Itraconazole and Terbinafine in Mucormycosis: A Proof-of-Concept Analysis

“…A study done in Iran in 2017–2018 isolated the maximum number of R. arrhizus from 196 soil samples and also found seasonal variation in isolation of Mucorales. In their study a seasonal variation in the frequency of Mucorales in soil was detected, with a maximum of culture-positive soil samples detected in wet autumn (43.2%), followed by winter (23.4%), summer (19.7%) and spring (13.6%) 12…”

“…In their study a seasonal variation in the frequency of Mucorales in soil was detected, with a maximum of culturepositive soil samples detected in wet autumn (43.2%), followed by winter (23.4%), summer (19.7%) and spring (13.6%). 12 Majority of these species have low MIC to AMB and PSC. Espinel-Ingroff et al 10 have also demonstrated similar findings in a multicentric study done in 13 centers worldwide.…”

New Insights on Mucormycosis and Its Association With the COVID-19 Pandemic

“…Moreover, Mucorales species are diverse across different countries. For example, Lichtheimia species are widespread in Europe and completely absent from the Americas [ 8 ]. Mucormycosis is also called zygomycosis or phycomycosis, and it is known misleadingly as ‘black fungus’, perhaps because of it may induce tissue necrosis, which eventually tends to be black in color [ 9 ].…”

COVID-19-Associated Mucormycosis, A New Incident in Recent Time: Is An Emerging Disease in The Near Future Impending?

“…Early detection of mucormycosis is important, as it can improve the prognosis. 30 31 32 According to studies, it improves survival, can minimize the need for or degree of surgical resection, and decrease disfigurement and suffering. 33 Since the illness is so uncommon, having a high index of suspicion is crucial.…”