The fear was that contact lens wearers who used their solution were at higher risk of acanthamoebic keratitis than contact lens wearers who used other solutions. The manufacturer recalled the product after the Centers for Disease Control in the United States found that 21 people had possibly received an Acanthamoeba infection after using Complete Moisture Plus in the month prior to diagnosis. As a bacterial reservoir
Several species of bacteria that can cause human disease are also able to infect and replicate within Acanthamoeba species. These include Legionella pneumophila, Pseudomonas aeruginosa, and some strains of Escherichia coli and Staphylococcus aureus. For some of these bacteria, replication inside Acanthamoeba has been associated with enhanced growth in macrophages, and increased resistance to some antibiotics. Furthermore, due to the high prevalence of Acanthamoeba in the environment, these amoebae have been proposed to serve as an environmental reservoir for some human pathogens. Ecology
A. castellanii can be found at high densities in various soil ecosystems. It preys on bacteria, but also fungi and other protozoa. This species is able to lyse bacteria and produce a wide range of enzymes, such as cellulases or chitinases, and probably contributes to the breakdown of organic matter in soil, contributing to the microbial loop.
XP repair proteins
The XPA protein acts during NER as a scaffold for assembly of other DNA repair proteins at sites of DNA damage to ensure appropriate excision of the damage.The XPB (ERCC3) protein is employed in unwinding the DNA double helix after DNA damage is initially recognized. Mutations in the XPB(ERCC3) gene can lead to XP or XP combined with Cockayne syndrome.The XPC protein forms a complex with RAD23B protein to form the initial damage recognition factor in global genomic nucleotide excision repair (GG-NER). This complex recognizes a wide variety of damages that thermodynamically destabilize DNA duplexes.The XPD (ERCC2) protein, in combination with the XPB helicase-containing transcription/repair complex TFIIH, is employed in unwinding the DNA duplex after damage is initially recognized. Mutations in the XPD(ERCC2) gene cause a variety of syndromes; XP, trichothiodystrophy (TTD), or a combination of XP and Cockayne syndrome (XPCS). Both trichothiodystrophy and Cockayne syndrome display features of premature aging, suggesting an association between deficient DNA repair and premature aging (see DNA damage theory of aging). XPE is a heterodimeric protein composed of two subunits. The larger subunit DDB1 primarily functions as a core component of CUL4A- and CUL4B-based E3 ubiquitin ligase complexes. Substrates that are ubiquitinnated by these complexes include proteins employed in DNA repair.The XPF (ERCC4) protein together with the ERCC1 protein forms a complex usually designated ERCC1-XPF. This complex separates the DNA helix for a short distance on either side of the site of damage.