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PloS One 2022Free-living amoebae (FLA) are gaining attention due to the increasing number of related grave central nervous system (CNS) and sight-threatening eye infections and their...
Isolation and morphological and molecular characterization of waterborne free-living amoebae: Evidence of potentially pathogenic Acanthamoeba and Vahlkampfiidae in Assiut, Upper Egypt.
Free-living amoebae (FLA) are gaining attention due to the increasing number of related grave central nervous system (CNS) and sight-threatening eye infections and their role as Trojan horses for many bacteria and viruses. This study was conducted in Assiut City, Egypt to detect the presence of FLA in different water sources using morphological and molecular approaches and determine their potential pathogenicity. A total of 188 water samples (100 tap, 80 tank, and 8 swimming pool samples) were collected, cultivated on non-nutrient agar seeded with Escherichia coli, and inspected for FLA. Thermo- and osmo-tolerance assays were performed to determine their pathogenicity. Polymerase chain reaction and sequence analysis were performed to confirm the identification and analyze the genotype. Overall, 52 samples (27.7%) were positive for FLA. Of these, 20.7% were identified as Acanthamoeba, 1.6% as Vahlkampfiidae, and 5.3% as mixed Acanthamoeba and Vahlkampfiidae. Seven species of Acanthamoeba were recognized, of which A. triangularis, A. polyphaga, A. lenticulata, and A. culbertsoni are thermo- and osmo-tolerant, and A. astronyxis, A. comandoni, and A. echinulata are non-thermo- and non-osmo-tolerant. The phylogeny analysis revealed T4 and T7 genotypes. Among Vahlkampfiids, 61.5% were identified as thermo- and osmo-tolerant Vahlkampfia, and 30.8% were identified as non-pathogenic Naegleria. One isolate (7.7%) was identified as potentially pathogenic Allovahlkampfia, as confirmed by sequencing. This is the first report documenting the occurrence and phylogeny of waterborne FLA (Acanthamoeba/Vahlkampfiidae) in Assiut, Egypt. The presence of potentially pathogenic FLA highlights the possible health hazards and the need for preventive measures.
Topics: Acanthamoeba; Amoeba; Egypt; Naegleria; Water
PubMed: 35802617
DOI: 10.1371/journal.pone.0267591 -
Journal of Parasitic Diseases :... Sep 2019keratitis (AK) is a severe corneal disease that was reported by WHO as the second most common infectious cause of blindness after trachoma; contact lens wear is...
keratitis (AK) is a severe corneal disease that was reported by WHO as the second most common infectious cause of blindness after trachoma; contact lens wear is considered one of the main risk factors in its transmission. Thus, the treatment of AK is crucial but, the inability of medical agents to completely eradicate the resistant cyst, together with their toxic effects, suggest that new agents are needed. Vinegar has been known long ago as a simple and available disinfectant with antimicrobial effects, so the present study aimed to test the effect of different concentrations of vinegar solution on isolate, along the period of 1 h in comparison to parasite and chlorhexidine controls. Post hoc test analysis revealed a highly significant difference between the vinegar-treated parasites and both controls, as regards the viable and non-viable mean cysts count. Vinegar concentration of 5% exhibited the highest mean of non-viable cysts along the time intervals, while the lowest was shown with 0.04% where also, no viable cysts were detected at 60 min. All tested concentrations behaved in a time-dependent manner. There was a positive correlation with a significant outcome between the different concentrations and the mean of the non-viable parasites along time. Transmission electron microscopy of treated cysts revealed corrugated altered cell wall with loss of ridges and detachment and shrinkage of content. Treated trophozoites showed flattening of the acanthopodia with thinned out plasma membrane and degenerated cytoplasmic content. The study highlighted the potential use of vinegar as an adjuvant in the prevention and treatment of AK.
PubMed: 31406399
DOI: 10.1007/s12639-019-01098-3 -
Folia Parasitologica Dec 2022Species of Acanthamoeba Volkonsky, 1931 are the commonest among free-living amoebae that are widespread in different water resources but with lacking phylogenetic data....
Species of Acanthamoeba Volkonsky, 1931 are the commonest among free-living amoebae that are widespread in different water resources but with lacking phylogenetic data. This study aims at detecting molecular prevalence and genetic diversity of Acanthamoeba isolates in Kafrelsheikh Governorate, Egypt. Forty-eight water samples were collected from 12 swimming pools; four samples during each season over one year. Samples were filtered, cultivated on non-nutrient agar plates and examined microscopically. Polymerase chain reaction (PCR) and sequence analysis of positive samples targeting diagnostic fragment 3 (DF3) of the small subunit rRNA gene were done. Cultivation succeeded to detect 14 (29%) positive samples while PCR missed three positive samples. The obtained sequences were phylogenetically analysed. The phylogenetic tree was constructed for them with sequences of reference species from the NCBI database. The identified species were Acanthamoeba castellanii Douglas, 1930 (T4), A. astronyxis (Ray et Hayes, 1954) (T9) and A. hatchetti Sawyer, Visvesvara et Harke, 1977 (T11). The prevalence of species of Acanthamoeba was higher during summer and fall. Therefore, the control of the presence of Acanthmoeba spp. in swimming pools needs immediate, effective and practical measures to prevent and control infection with species of Acanthamoeba.
Topics: Acanthamoeba; Phylogeny; Egypt; Swimming Pools; Genotype
PubMed: 36534004
DOI: 10.14411/fp.2022.029