A quantitative method to evaluate neutralizer toxicity against Acanthamoeba castellanii

Area of Science:

• Microbiology
• Parasitology
• Toxicology

Background:

• Standardized methods for quantifying neutralizer toxicity against Acanthamoeba castellanii are lacking.
• Accurate toxicity assessment is crucial for antimicrobial agent development and safety.

Purpose of the Study:

• To establish a quantitative methodology for evaluating neutralizer toxicity against A. castellanii.
• To compare the reliability of microtiter and hemacytometer cell counting methods.
• To assess the toxicity of Dey-Engley neutralizing broth to A. castellanii.

Main Methods:

• A quantitative microtiter assay was employed to enumerate A. castellanii viability.
• The 50% lethal dose (LD50) endpoint was used for toxicity evaluation.
• Microtiter counts were compared against hemacytometer counts; Dey-Engley neutralizing broth was tested against Page's saline.

Main Results:

• Microtiter viable cell counts were lower than hemacytometer counts, but demonstrated greater reliability.
• Dey-Engley neutralizing broth exhibited no significant toxicity to A. castellanii.
• The developed microtiter method provides consistent and simple toxicity evaluations.

Conclusions:

• The presented microtiter method offers a reliable and quantitative approach for assessing neutralizer toxicity against A. castellanii.
• Dey-Engley neutralizing broth is confirmed as non-toxic to A. castellanii under the tested conditions.
• This methodology provides a much-needed standard for evaluating the safety of antimicrobial neutralizers.