Primary Cutaneous Mucormycosis Produced by the New Species Apophysomyces mexicanus

Abstract

A case of fungal necrotizing fasciitis that appeared in an immunocompetent Mexican woman after a car accident is described. The patient did not respond to antifungal treatment and died 4 days later. The fungus was molecularly identified as a new species of Apophysomyces, namely, Apophysomyces mexicanus. CASE REPORTA 46-year-old woman was admitted to an emergency department 6 days after she suffered a rollover car accident, which occurred on a highway in a semiarid region with 75% relative humidity; the patient was ejected 10 meters from the car during the rollover, with consequent T12 vertebral fracture, Frankel grade B spinal cord injury, and superficial abrasions and lacerations over the neck. The patient was immobilized with a Philadelphia collar immediately after the accident, and her medical history showed type 2 diabetes mellitus, controlled with metformin-glibenclamide, and an allergy to nonsteroidal anti-inflammatory drugs. She received initial treatment in a regional hospital and was transferred to the emergency department of the Lic. Adolfo López Mateos Hospital 6 days later. After the collar was removed, a 3-cm-diameter fixed, irregular, red, swollen area was observed with a central necrosis of about 1 cm in length over the right posterior cervical triangle (Fig. 1A), along with multiple abrasions of the neck. Initial laboratory test results showed leukocytosis of 17 ϫ 10 9 /liter, glucose at 10.77 mmol/liter, hemoglobin at 121 g/liter, hematocrit at 0.352 liter/liter, urea nitrogen at 3.92 mmol/ liter, urea at 3.92 mmol/liter, and creatinine at 53.04 mmol/liter. A computed tomography (CT) scan of the neck after administration of contrast material revealed isodense homogeneous soft tissue bulking posterior to the sternocleidomastoid muscle, with no evidence of foreign bodies. An escharectomy was carried out, and ceftriaxone (2 g/day) and clindamycin (1.2 g/day) were administered. On the second day, the cellulitis and necrosis areas expanded to 10 cm in length (Fig. 1B), affecting the posterior, muscular, and submandibular cervical triangles. The patient underwent surgical exploration of the neck and debridement, which showed necrotic tissue that extended as far as the muscle. Material was collected and sent to the laboratory for histopathological examination and microbial culture. Direct mountings on KOH (10% [wt/vol]) showed dichotomously branched, broad coenocytic hyphae (Fig. 1C), similar to those observed on hematoxylin-eosin histopathology preparations (Fig. 1D). Culturing on Sabouraud dextrose agar (Difco/Becton Dickinson, Mexico) produced white, cottony fungal colonies made of pauciseptated hyphae evocative of a fungus belonging to Mucorales. Consequently, primary cutaneous mucormycosis (PCM) was diagnosed; therefore, amphotericin B deoxycholate (0.5 mg/kg of body weight/ day) and fluconazole (400 mg/day) were administered. A second debridement removed all necrotic tissue, reaching the free edges of the lesion and leaving a surgical mark (10 by 15 cm) (Fig. 1E). Despite antifungal treatment, th...

Mucormycosis: Battle with the Deadly Enemy over a Five-Year Period in India

“…A. elegans was first isolated by Misra et al in 1979 from soil samples collected from a mango orchard in northern India and was the only species in the genus till recently [ 13 ]. Now, five species of Apophysomyces are known, i.e., A. elegans , A. variabilis , A. ossiformis , A. trapeziformis , and a newly recognized species A. mexicanus [ 14 ]. Although infections like ROC or renal have been reported previously, the species of this genus are mainly associated to necrotizing fasciitis.…”

Mucormycosis

“…Cutaneous mucormycosis can occur in immunocompromised hosts either as localized or disseminated disease. 194 Cutaneous mucormycosis in immunocompetent hosts typically occurs due to traumatic injury, 13,20,27,[195][196][197] surgery, 30 burns, 7,198 natural disasters, 199-201 combat, 96 insect or animal bites, 202,203 or inoculation of contaminated soil, plants, grasses, thorns, or water. 7,13,197 Mucormycosis can spread rapidly in skin, subcutaneous tissues, fascia, and bone.…”

Emerging infections caused by non- Aspergillus filamentous fungi

“…Notably, outbreaks of infection have followed natural disasters, well illustrated by the cluster of Apophysomyces trapeziformis softtissue infections following a tornado in Joplin, USA (see Outbreaks section). Infection caused by more uncommon Apophysomyces species include eight case reports of Apophysomyces variabilis infections, all of necrotizing soft-tissue infection [19,20], and one case of a novel species Apophysomyces mexicanus with soft-tissue infection following traumatic inoculation [21].…”