Correlation of fungal cultures from non-sterile sites and Galactomannan assay with the diagnosis of aspergillosis and mucormycosis based on sterile culture results and histopathologic findings

Abstract

Background: Data on whether positive non-sterile fungal culture has the same clinical value as a positive galactomannan (GM) result are limited.

Methods: Patients with biopsy-proven invasive aspergillosis or mucormycosis (over an 8-year period) in whom the results of GM and fungal culture of sputum and/or sinus aspirates were available were enrolled. Biopsy-proven cases were defined if fungal culture from a sterile biopsy specimen gave a positive result and/or hyphae were demonstrated by immunohistochemical staining for aspergillosis and mucormycosis.

Results: A total of 71 patients comprising 30 biopsy-proven cases of aspergillosis including 13 cases with positive sterile cultures and 41 biopsy-proven cases of mucormycosis including eight cases with positive sterile cultures were enrolled. Of 30 patients with aspergillosis, 15 (50%) revealed Aspergillus spp. growth from non-sterile site and none exhibited the agents of mucormycosis growth from non-sterile site. However, of 41 patients with mucormycosis, eight (20%) revealed the agents of mucormycosis growth from non-sterile site and three (7%) exhibited Aspergillus spp. growth from non-sterile site. In terms of GM assays, 23 (77%) of 30 patients with aspergillosis revealed positive GM results, and 17 (41%) of 41 patients with mucormycosis revealed positive GM assays. So, positive fungal culture from non-sterile site (88% [23/26]) were better correlated with the diagnosis than positive GM assay (57% [23/40]) (p value = .01).

Conclusions: Positive fungal cultures from non-sterile sites better correlate with the diagnosis of aspergillosis and mucormycosis based on sterile culture results and histopathological findings than positive GM results.

Keywords:

• Mucormycosis
• aspergillosis
• non-sterile culture
• galactomannan
• diagnosis

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This study was supported by a grant from the Korea Health Technology R&D Project through the Korea Health Industry Development Institute (KHIDI), funded by the Ministry of Health & Welfare, Republic of Korea [grant no. HI16C0272].