National Outbreak of Acanthamoeba Keratitis Associated with Use of a Contact Lens Solution, United States

Premarket standardized testing for Acanthamoeba spp. is warranted

History and symptom taking in contact lens fitting and aftercare.

AIM: To appraise history and symptom taking for contact lens consultations, to determine current practice and to make recommendations for best practice. METHOD: The peer reviewed academic literature was reviewed and the results informed a survey completed by 256 eye care practitioners (ECPs) on their current practice and influences. RESULTS: The last eye-test date, last contact lens aftercare (for existing wearers) and reason for visit are key questions for most ECPs. Detailed use of contact lens questions are more commonly applied in aftercares than when refitting patients who have previously discontinued wear (87% vs 56% use), whereas questions on ocular and general history, medication and lifestyle were generally more commonly utilised for new patients than in aftercares (72% vs 50%). 75% of ECPs requested patients bring a list of their medication to appointments. Differential diagnosis questioning was thorough in most ECPs (87% of relevant questions asked). Attempts to optimise compliance included oral instruction (95% always) and written patient instructions (95% at least sometimes). Abbreviations were used by 39% of respondents (26% used ones provided by a professional body). CONCLUSION: There is scope for more consistency in history and symptom taking for contact lens consultations and recommendations are made

Do allelopathic compounds in invasive Solidago canadensis s.l. restrain the native European flora?

1. One mechanism explaining the success of invasive weeds may be the production and release of allelopathic compounds by the invader that, due to a lack of co-evolutionary history, have harmful effects on plant neighbours in the introduced range. 2. We partially tested this hypothesis by growing seven competing native European plant species either with the introduced Solidago canadensis s.l., one of the most successful invasive plants in Europe or on soil pre-cultivated with S. canadensis. We added activated carbon to the soil to neutralize organic chemical compounds with putative allelopathic effects. Furthermore, we added unsterilized soil inocula from the introduced (Switzerland) or native (USA) range to the soil to test potential confounding effects of soil microbes on invasion success. Untreated sterilized soil served as control. 3. Five out of the seven native species were more competitive against the invasive species in soils with activated carbon than without, supporting the allelopathy hypothesis. However, competitive outcomes were also influenced by the two sources of soil inoculum and by interactive effects of soil inoculum and Solidago origin suggesting that soil microbes alter allelopathic effects. 4. Achillea millefolium, the species least affected by the presence of S. canadensis and with no response to the activated carbon treatment is the only species used in this experiment reported to grow within Solidago stands in Europe, whereas the other European species tested tend to grow at the periphery of invasive Solidago stands. 5. Chemical analysis by LC-MS of Solidago root extracts revealed four main secondary chemical compounds with potential allelopathic effects. Root exudates of Solidago showed a significant inhibitory effect on growth of the model plant species Arabidopsis thaliana. The magnitude of inhibition increased with increasing concentration of the extract. 6. Synthesis. Levels of the four compounds were lower in Solidago populations from the invasive range than in populations of the same ploidy level from the native range. This suggests lower investment of invasive plants into these secondary compounds, possibly because of a higher susceptibility of plant competitors in the invasive range to these substances