Corneal and conjunctival infections

Colin, J; Hasle, Daniel

doi:10.1097/00055735-199308000-00009

Cited by 1 publication

(1 citation statement)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Activity assays. The activity of two drugs was tested on selected strains of Acanthamoeba from this study: chlorhexidine (chlorhexidine digluconate; Alfa Aesar), a standard antiseptic belonging to the biguanide family of compounds which are commonly used in contact lens maintenance solutions; and ciprofloxacin (ciprofloxacin lactate; Dr. Ehrenstorfer), an antibiotic that has been previously used for the treatment of AK (Colin & Hasle, 1993;Wynter-Allison et al, 2005). For the sensitivity and activity assays, a type strain from the American Type Culture Collection, Acanthamoeba castellanii (Neff strain) ATCC 30010, genotype T4, was used as a control.…”

Section: Methodsmentioning

confidence: 99%

The potential pathogenicity of chlorhexidine-sensitive Acanthamoeba strains isolated from contact lens cases from asymptomatic individuals in Tenerife, Canary Islands, Spain

Martín-Navarro

Lorenzo‐Morales

Cabrera-Serra

et al. 2008

Journal of Medical Microbiology

View full text Add to dashboard Cite

Pathogenic strains of the genus Acanthamoeba are causative agents of a serious sightthreatening infection of the eye known as Acanthamoeba keratitis. The prevalence of this infection has risen in the past 20 years, mainly due to the increase in number of contact lens wearers. In this study, the prevalence of Acanthamoeba in a risk group constituted by asymptomatic contact lens wearers from Tenerife, Canary Islands, Spain, was evaluated. Contact lenses and contact lens cases were analysed for the presence of Acanthamoeba isolates. The isolates' genotypes were also determined after rDNA sequencing. The pathogenic potential of the isolated strains was subsequently established using previously described molecular and biochemical assays, which allowed the selection of three strains with high pathogenic potential. Furthermore, the sensitivity of these isolates against two standard drugs, ciprofloxacin and chlorhexidine, was analysed. As the three selected strains were sensitive to chlorhexidine, its activity and IC 50 were evaluated. Chlorhexidine was found to be active against these strains and the obtained IC 50 values were compared to the concentrations of this drug present in contact lens maintenance solutions. It was observed that the measured IC 50 was higher than the concentration found in these maintenance solutions. Therefore, the ineffectiveness of chlorhexidine-containing contact lens maintenance solutions against potentially pathogenic strains of Acanthamoeba is demonstrated in this study. INTRODUCTIONFree-living amoebae of the genus Acanthamoeba are ubiquitous protozoans that pervade the entire environment and include amphizoic strains that are pathogenic to humans and animals (Schuster & Visvesvara, 2004a). These protozoans are opportunistic causal agents of a sightthreatening ulceration of the cornea called Acanthamoeba keratitis (AK), disseminated infections (mostly cutaneous and nasopharyngeal) and a usually fatal granulomatous amoebic encephalitis (Khan, 2003(Khan, , 2006Marciano-Cabral & Cabral, 2003;Schuster & Visvesvara, 2004a).AK in developed countries is often associated with inadequate care of the contact lenses and also as a consequence of corneal trauma whereas in developing nations most cases occur as a result of ocular trauma (Seal et al., 1999;Ibrahim et al., 2007;Ozkoc et al., 2008). AK symptoms are nonspecific and can be misdiagnosed as a viral, bacterial or fungal keratitis. Thus an early diagnosis is required to achieve a successful therapeutic outcome (Martínez & Visvesvara, 1991;Lorenzo-Morales et al., 2007). Currently, the recommended treatment regimen includes a biguanide [0.02 % polyhexamethylene biguanide (PHMB) or 0.02 % chlorhexidine digluconate] together with a diamidine (0.1 % propamidine isethionate, also known as Brolene, or 0.1 % hexamidine, also known as Desomedine) (Khan, 2006). Biguanides are most often used due to their excellence in the treatment of AK and are frequently combined with a diamidine due to their presumed additive anti-amoebic effect (Hay et al., 1994;Sch...

show abstract

Section: Methodsmentioning

confidence: 99%