Apophysomyces elegans: an emerging zygomycete in India

Abstract

Apophysomyces elegans was considered a rare but medically important zygomycete. We analyzed the clinical records of eight patients from a single center in whom zygomycosis due to A. elegans was diagnosed over a span of 25 months. We also attempted a DNA-based method for rapid identification of the fungi and looked for interstrain polymorphism using microsattelite primers. Three patients had cutaneous and subcutaneous infections, three had isolated renal involvement, one had rhino-orbital tissue infection, and the final patient had a disseminated infection involving the spleen and kidney. Underlying illnesses were found in two patients, one with diabetes mellitus and the other with chronic alcoholism. A history of traumatic implantation was available for three patients. All except two of the patients responded to surgical and/or medical therapy; the diagnosis for the two exceptions was made at the terminal stage of infection. Restriction enzyme (MboI, MspI, HinfI) digestion of the PCR-amplified internal transcribed spacer region helped with the rapid and specific identification of A. elegans. The strains could be divided into two groups according to their patterns, with clustering into one pattern obtained by using microsatellite [(GTG)(5) and (GAC)(5)] PCR fingerprinting. The study highlights the epidemiology, clinical spectrum, and diagnosis of emerging A. elegans infections.

FIG. 1.

(a) PCR amplification of ITS regions of different zygomycetes. (b) Restriction digestion patterns of products amplified from the ITS region after digestion with MboI. (c) Restriction digestion patterns of products amplified from the ITS region after digestion with MspI. (d) Restriction digestion patterns of products amplified from the ITS region after digestion with HinfI. (a to d) Lanes: M, marker; 1, A. elegans (CDC B5656); 2 to 10, A. elegans isolated from clinical samples (strains MCCL 102001, MCCL 102002, MCCL 102005, MCCL 102008, MCCL 102009, MCCL 102014, MCCL 102015, MCCL 102017, and MCCL 102012, respectively); 11, A. corymbifera (CDC 5792); 12, A. corymbifera (MCCL 700003); 13, S. vasiformis (MCCL 1110004); 14, R. arrhizus (MCCL 710010); 15, R. pusillus (MCCL 720006); 16, B. ranarum (MCCL W6); and 17, M. circinelloides (MCCL 690001).

FIG. 2.

PCR fingerprinting with microsatellite oligonucleotide primer (GTG)₅ of different zygomycetes. Lanes: M, marker; 1, A. elegans (CDC B5656); 2 to 10, A. elegans isolated from clinical samples (strains MCCL 102001, MCCL 102002, MCCL 102005, MCCL 102008, MCCL 102009, MCCL 102014, MCCL 102015, MCCL 102017, and MCCL 102012, respectively); 11, A. corymbifera (CDC 5792); 12, A. corymbifera (MCCL 700003); 13, S. vasiformis (MCCL 1110004); 14, R. arrhizus (MCCL 710010); 15, R. pusillus (MCCL 720006); and 16, B. ranarum (MCCL W6).

FIG. 3.

PCR fingerprinting with microsatellite oligonucleotide primer (GAC)₅ of different zygomycetes. Lanes: M, marker; 1, A. elegans (CDC B5656); 2 to 10, A. elegans isolated from clinical samples (strains MCCL 102001, MCCL 102002, MCCL 102005, MCCL 102008, MCCL 102009, MCCL 102014, MCCL 102015, MCCL 102017, and MCCL 102012, respectively); 11, A. corymbifera (CDC 5792); 12, A. corymbifera (MCCL 700003); 13, S. vasiformis (MCCL 1110004); 14, R. arrhizus (MCCL 710010); 15, R. pusillus (MCCL 720006); and 16, B. ranarum (MCCL W6).