Treating Pythiosis with Antibacterial Drugs Targeting Protein Synthesis: An Overview

Abstract

This review article explores the effectiveness of antibacterial drugs that inhibit protein synthesis in treating pythiosis, a difficult-to-treat infection caused by Pythium insidiosum. The article highlights the susceptibility of P. insidiosum to antibacterial drugs, such as macrolides, oxazolidinones, and tetracyclines. We examine various studies, including in vitro tests, experimental infection models, and clinical case reports. Based on our synthesis of these findings, we highlight the potential of these drugs in managing pythiosis, primarily when combined with surgical interventions. The review emphasizes the need for personalized treatment strategies and further research to establish standardized testing protocols and optimize therapeutic approaches.

Keywords: Pythiosis treatment; Pythium insidiosum; azithromycin; linezolid; protein-inhibiting antibacterials.

Figure 1

Microscopic morphology of Pythium insidiosum. (A). Hyphae of P. insidiosum (black arrow) and a cluster of encysted zoospores (black arrowhead) (light microscopy, 400× magnification). (B). Image from a scanning electron microscope depicting the three-dimensional structure of P. insidiosum mycelium (white arrow).

Figure 2

Pythium insidiosum growth observed on a single plate after 48 h incubation at 35 °C on Muller–Hinton agar, demonstrating the effect of a minocycline (30 µg) disk. A marked growth inhibition is noticeable in the area surrounding the minocycline disk, illustrating its antibacterial activity against P. insidiosum.

Figure 3

Mean diameters of Pythium insidiosum growth inhibition zones around disks containing antibacterial drugs, with black bars representing results from Loreto et al. [7] and white bars indicating findings from Bagga et al. [8].

Figure 4

Etest assay (top left, right, and bottom left) demonstrating the elliptical inhibition zones (MIC, indicated by yellow arrows) of Pythium insidiosum induced by azithromycin (AZ), linezolid (LZ), and minocycline (MC), respectively. Disk diffusion (bottom right) exhibits the halo of linezolid (LNZ) (yellow arrows). Note the absence of inhibition with the antifungal agents amphotericin B (AP) and fluconazole (FL) in the top left and the right plates.