Acanthamoeba mauritaniensis genotype T4D: An environmental isolate displays pathogenic behavior

Area of Science:

• Microbiology
• Cell Biology
• Parasitology

Background:

• Acanthamoeba species are ubiquitous free-living amoebae.
• Pathogenic Acanthamoeba strains cause severe human infections like keratitis and encephalitis.
• Proteases are key virulence factors in pathogenic Acanthamoeba.

Purpose of the Study:

• To investigate the pathogenic potential and protease activity of Acanthamoeba mauritaniensis.
• To compare the cytopathic effects of A. mauritaniensis with Acanthamoeba castellanii.
• To analyze the impact of A. mauritaniensis proteases on host cell tight junctions.

Main Methods:

• Cell culture assays to assess cytopathic effects on RCE1(5T5) and MDCK cells.
• Biochemical characterization of proteases in total crude extracts and conditioned medium.
• Zymography and Azocoll assays to identify protease activities.
• Analysis of tight junction protein integrity and transepithelial electrical resistance.
• Genotyping of the Acanthamoeba isolate.

Main Results:

• A. mauritaniensis induced significant cytopathic effects on RCE1(5T5) and MDCK cells.
• Serine proteases were identified as the most active proteases in both total crude extracts and conditioned medium.
• A. mauritaniensis proteases, particularly serine proteases, degraded tight junction proteins and altered cell barrier function.
• The isolate was identified as Acanthamoeba genotype T4D.

Conclusions:

• Acanthamoeba mauritaniensis genotype T4D exhibits pathogenic-like behaviors, including cell damage and tight junction disruption.
• The findings suggest that nonpathogenic Acanthamoeba isolates may possess virulence factors similar to pathogenic strains.
• Further research is warranted to fully understand the clinical implications of Acanthamoeba genotype T4D.