STERIS SA R&D, Fontenay-aux-Roses, France.
J Clin Microbiol. 2010 Aug;48(8):2689-97. doi: 10.1128/JCM.00309-10. Epub 2010 Jun 2.
Free-living amoebae that belong to the genus Acanthamoeba are widespread in the environment, including water. They are responsible for human infections and can host pathogenic microorganisms. Under unfavorable conditions, they form cysts with high levels of resistance to disinfection methods, thus potentially representing a threat to public health. In the present study we evaluated the efficacies of various biocides against trophozoites and cysts of several Acanthamoeba strains. We demonstrated that disinfectant efficacy varied depending on the strains tested, with environmental strains demonstrating greater resistance than collection strains. Trophozoites were inactivated by all treatments except those using glutaraldehyde as an active compound: for these treatments, we observed resistance even after 30 min exposure. Cysts resisted many treatments, including certain conditions with glutaraldehyde and other biocides. Moist heat at 55 degrees C was not efficient against cysts, whereas exposure at 65 degrees C was. Several chemical formulations containing peracetic acid, hydrogen peroxide, or ortho-phthalaldehyde presented greater efficacy than glutaraldehyde, as did ethanol and sodium hypochlorite; however, some of these treatments required relatively long incubation times to achieve cyst inactivation. Amoebal cysts can be highly resistant to some high-level disinfectants, which has implications for clinical practice. These results highlight the need to consider the effective disinfection of protozoa in their vegetative and resistant forms due to their intrinsic resistance. This is important not only to prevent the transmission of protozoa themselves but also due to the risks associated with a range of microbial pathogens that are found to be associated intracellularly with these microorganisms.
自由生活的阿米巴原虫属于棘阿米巴属，广泛存在于环境中，包括水中。它们是人类感染的原因，并可以携带病原微生物。在不利条件下，它们形成具有高抗消毒方法能力的囊，因此可能对公共卫生构成威胁。在本研究中，我们评估了各种消毒剂对几种棘阿米巴菌株的滋养体和囊的功效。我们证明，消毒功效因测试的菌株而异，环境菌株比收集菌株具有更大的抗性。除了使用戊二醛作为活性化合物的处理方法外，所有处理方法都能使滋养体失活：对于这些处理方法，即使暴露 30 分钟后，我们也观察到了抗性。囊对许多处理方法具有抗性，包括戊二醛和其他消毒剂的某些条件。55°C 的湿热对囊无效，而 65°C 的暴露则有效。几种含有过氧乙酸、过氧化氢或邻苯二醛的化学配方比戊二醛更有效，乙醇和次氯酸钠也是如此；然而，其中一些处理方法需要相对较长的孵育时间才能达到囊失活。阿米巴原虫的囊可以对一些高水平消毒剂具有高度抗性，这对临床实践有影响。这些结果强调了由于其内在抗性，需要考虑有效消毒原生动物的营养体和抗性形式。这不仅对于防止原生动物本身的传播很重要，而且对于与这些微生物相关的一系列微生物病原体的风险也很重要。
