Cunninghamella arunalokei a New Species of Cunninghamella from India Causing Disease in an Immunocompetent Individual.

Vinaykumar Hallur,Shivaprakash Mandya Rudramurthy,Shamanth Adekhandi Shankarnarayan,Mukund Sable,Chappity Preetam,Prashanth Purushotham,Hariprasath Prakash,Nerbadyswari Deep Bag,Rabindra Senapati

doi:10.3390/jof7080670

Abstract

Mucormycosis due to Cunninghamella spp. is a rare disease, especially in immunocompetent individuals. Here, we describe the isolation and characterization of a new species of Cunninghamella, causing chronic rhino-orbital-cerebral disease, and review cases of mucormycosis due to Cunninghamella spp. in immunocompetent individuals. The Basic Local Alignment Search Tool (BLAST) analysis of the internal transcribed spacer region (ITS) sequence of isolate NCCPF 890012 showed 90% similarity with Cunninghamella bigelovii, while the large ribosomal subunit (28S) and translation elongation factor-1 alpha (EF-1 alpha) gene sequences showed 98% identity. Further, the phylogenetic analysis with concatenated sequences clustered isolate (NCCPF 890012) closely with C. bigelovii. The ITS sequence showed the maximum variation among three genes analyzed and helped in the new species’ delineation. Comparison of the assembled whole genome of NCCPF 890012 with other Mucorales using 123 single-copy orthologous genes showed clustering within the genus Cunninghamella. Based on these findings, the isolate is considered to be a new species of Cunninghamella and designated as Cunninghamella arunalokei sp. nov. Despite repeated debridement and antifungal treatment, the patient had multiple recurrences with intracranial extension and succumbed to the illness.

Highlights

We report a case of chronic invasive rhino-orbital-cerebral mucormycosis (ROCM) due to novel Cunninghamella species in India
Physical examination details, and biopsy for histopathology and microbiology workup were collected at the time of admission at All India Institute of Medical Sciences (AIIMS), Bhubaneswar, India
Histopathological examination report of the biopsied lesion and radiological imaging had confirmed the diagnosis of invasive mucormycosis with involvement of the facial skin, subcutaneous tissue, and the maxillary sinuses

Summary

Introduction

Mucormycosis is an angioinvasive disease often associated with high morbidity and mortality [1]. Infections due to Cunninghamella species are relatively rare in India in comparison to other countries [2]. Patients with hematological malignancy and hematopoietic stem cell transplant have an increased risk of acquiring mucormycosis due to Cunninghamella species which predominantly presents as pulmonary and disseminated infections [3]. Previous data show that Cunninghamella species are associated with high mortality compared to Rhizopus species [3,4]. A high mortality rate is possibly due to the pathogen’s virulence compared to other Mucorales [5]

Methods

Results

Discussion

Conclusion