Emerging newer species of Apophysomyces and Saksenaea from a tertiary care centre from north India

J Chander1, N Singla1, N Gulati1, RPS Punia2, A Attri3, A Alastruey-Izquierdo4, AM Stchigel5, JF Cano5, J Guarro5

Author address: 

1Microbiology, Government Medical College Hospital, Chandigarh, India 2Pathology, Government Medical College Hospital, Chandigarh, India 3General Surgery, Government Medical College Hospital, Chandigarh, India 4Mycology Reference Laboratory, Spanish National Center for Microbiology, Instituto de Salud Carlos III, Madrid, Spain 5Mycology Unit, Medical School and IISPV, Universitat Rovira I Virgili, Reus, Spain

Abstract: 

Purpose: Saksenaea and Apophysomyces are two Mucoralean fungi being isolated from soil, dust and vegetative matter. These were isolated from India for the first time in 1953 and 1979, respectively. Their type species were Apophysomyces elegans and Saksenaea vasiformis however during recent times newer species have been described. Alvarez et al in 2010 considered A. elegans as a complex that included three species, A.ossiformis, A.trapeziformis and A variabilis however A.mexicanus was added subsequently, based on their genetic, physiological and morphological differences. Similarly, S.vasiformis was considered a complex that included two species, S. oblongispora and S.erythrospora however S.loutrophoriformis was subsequently added. In India, now A.variabilis has almost replaced A.elegans and S.erythrospora and S.loutrophoriformis are being reported in addition to S.vasiformis. The newer species of Apophysomyces and Saksenea are being presented from the Government Medical College Hospital, Chandigarh over a period of one decade.

Methods: The debrided necrotic skin tissue was processed as per standard mycological protocol over a period of ten years from August 2007 to September 2017. The clinical entity was diagnosed by mounting biopsy material on potassium hydroxide (10%), histopathology study of tissue sections stained by hematoxylin and eosin (H&E), periodic acid-Schiff (PAS) and Gomori methenamine silver (GMS) stainings as well as by fungal culture on conventional media, with morphological identification of isolates with LCB mount. The final diagnosis of isolates was established on the basis of molecular identification done at Mycology Unit, Reus (Spain). ITS region of isolates was sequenced and compared with those of type strains for final identification. The antifungal susceptibility testing of all the isolates was done by EUCAST method at Mycology Reference Centre, Madrid (Spain) depicting susceptibility to amphotericin B, posaconazole and itraconazole. All patients were treated with amphotericin B along with extensive surgical debridement of necrotic tissue.

Results: Out of 26 species of Apophysomyces, 23 were A.variabiliis and 3 were A.elegans. Out of 9 Saksenaea, 6 were A.erythrospora, 2 were A.vasiformis and 1 was S.loutrophoriformis. Diabetes mellitus, intramuscular injections at gluteal region were the main predisposing factors, while upper limb involvement, following medicated adhesive tape application, was also seen. Almost fifty percent patients responded well to the surgical debridement and liposomal amphotericin B; however, rest of them were either died or left against medical advice (LAMA) from the hospital as they could not afford the cost of antifungal regimens.

Conclusions: In India, more than seventy percent of cases caused by these emerging fungi, Apophysomyces and Saksenaea, since their discoveries and most of them are now caused by A. variabilis and S.erythrospora. Moreover, S.loutrophoriformis is being reported in the literature for the first time from India. This is very significant change in the prevalence of the Mucoralean fungi and underlying factors in soil and other areas are to be explored in details. Moreover, index of suspicion of fungal etiology should be kept very high to avoid any time wastage in establishing diagnosis and empirical treatment on bacterial lines. Early diagnosis, prompt and extensive surgical debridement and appropriate antifungal therapy are the key to treat such type of patients and their lives can be saved from these newly emerging species of Apophysomyces and Saksenaea.

2018

Full conference title: 

The 8th Advances Against Aspergillus, Lisbon Conference Center, Lisbon, Portugal
    • AAA 8th (2018)