0

Effect of povidone iodine, chlorhexidine digluconate and toyocamycin on amphizoic amoebic strains, infectious agents of Acanthamoeba keratitis - a growing threat to human health worldwide

Marcin Padzik, Wanda Baltaza, David Bruce Conn, Jacek P Szaflik, Lidia Chomicz

Ann Agric Environ Med. 2018 Dec 20;25(4):725-731.

PMID: 30586959

Abstract:

Introduction:
Free-living amoebae, ubiquitous in outer environments, in predisposing circumstances may exist as parasites, infectious agents of Acanthamoeba keratitis. In recent decades, the vision-threatening corneal infection is a growing human health threat worldwide, including Poland. The applied therapy is often ineffective due to diagnostic mistakes, various pathogenicity of Acanthamoeba strains and high resistance of cysts to drugs; many agents with possible anti-amoebic activity are still being tested. In the presented study, selected chemicals are investigated in terms of their in vitro effect on corneal and environmental Acanthamoeba strains.
Material and methods:
Samples of a corneal isolate from a patient with severe Acanthamoeba keratitis,of assessed on the basis of genotype associations of 18S rRNA and the type strain, Acanthamoeba castellanii Neff cultivated in bacteria-free condition, were exposed to povidone iodine, chlorhexidine digluconate or toyocamycin. In vitro population dynamics of the strains were monitored and compared to those of control cultures.
Results:
All chemicals showed anti-amoebic effects with different degrees of effectiveness. Significant differences were observed in the in vitro population dynamics, and the morpho-physiological status of A. castellanii Neff T4 and corneal strains determined as A. polyphaga T4 genotype, exposed to povidone iodine or toyocamycin, in comparison with chlorhexidine taken as reference.
Conclusions:
Time-dependent amoebstatic in vitro effects were demonstrated for all agents, in particular, the results of assays with povidone iodine are promising. No significant stimulation of encystation appeared; however, as cysticidal efficacy of chemicals is expected, complementary research is needed on different Acanthamoeba strains with modified agent concentrations and method application.

Chemicals Related in the Paper:

Catalog Number Product Name Structure CAS Number Price
AP606586 Toyocamycin Toyocamycin 606-58-6 Price
qrcode