The environmental source of emerging Apophysomyces variabilis infection in India.
The rare mucoraceous fungus, Apophysomyces species complex ranks second after Rhizopus arrhizus causing mucormycosis in India. The source of this agent in the environment is not clearly known. We conducted an environmental study to find its presence in Indian soil. The soil samples from different geographical locations were analyzed for isolation of Mucorales. Rhizopus arrhizus (24.6%) was most commonly isolated from soil, followed by Lichtheimia spp. (23.2%), Cunninghamella spp. (21.7%), Rhizopus microsporus (14%) and Apophysomyces spp. (4.5%). The isolation of Apophysomyces species complex was significantly associated with low nitrogen content of the soil. Based on sequencing of internal transcribed spacer (ITS) and 28S (D1/D2) regions of ribosomal DNA, the Apophysomyces isolates were identified as Apophysomyces variabilis with 98 to 100% similarity to type strain A. variabilis (CBS658.93). The analysis of amplified fragment length polymorphism (AFLP) fingerprinting data demonstrated genomic diversity of A. variabilis isolates with multiple clades (similarity 40-90%). The minimum inhibitory concentrations (MIC), MIC50 and MIC90 for A. variabilis isolates were 1 and 4 μg/ml for amphotericin B, 0.25 and 0.5 μg/ml for itraconazole, 0.125 and 0.25 μg/ml for posaconazole, 0.06 and 0.12 μg/ml for terbinafine, respectively. The present study revealed abundant presence of A. variabilis in Indian soil with low nitrogen content, its genetic heterogeneity and relatively high MICs for amphotericin B.
Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
Hariprasath
H
Prakash
Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
Anup Kumar
AK
Ghosh
Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
Shivaprakash Mandya
SM
Rudramurthy
Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
Raees Ahmad
RA
Paul
Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
Sunita
S
Gupta
Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research, Chandigarh, India.
Vishwanand
V
Negi
Department of Medical Microbiology, Postgraduate Institute of Medical Education and Research, Chandigarh, India arunaloke@hotmail.com.
Arunaloke
A
Chakrabarti
D054458:Amplified Fragment Length Polymorphism Analysis; D000935:Antifungal Agents / Q000494:pharmacology; D016000:Cluster Analysis; D004271:DNA, Fungal / Q000737:chemistry / Q000235:genetics; D004275:DNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D021903:DNA, Ribosomal Spacer / Q000737:chemistry / Q000235:genetics; D014644:Genetic Variation; D005838:Genotype; D007194:India; D008826:Microbial Sensitivity Tests; D009090:Mucorales / Q000145:classification* / Q000187:drug effects / Q000235:genetics / Q000302:isolation & purification*; D009091:Mucormycosis / Q000209:etiology*; D009584:Nitrogen / Q000032:analysis; D010802:Phylogeny; D012339:RNA, Ribosomal, 28S / Q000235:genetics; D017422:Sequence Analysis, DNA; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology
D000935:Antifungal Agents; D004271:DNA, Fungal; D004275:DNA, Ribosomal; D021903:DNA, Ribosomal Spacer; D012339:RNA, Ribosomal, 28S; D012987:Soil; D009584:Nitrogen
AFLP; Apophysomyces variabilis; Mucorales; amphotericin B; antifungal susceptibility testing; ecology; molecular typing