title: Genotype analysis of Acanthamoeba isolated from human nasal swabs in the Philippines.
abstract: OBJECTIVE
  To analyze the genotypes of Acanthamoeba species isolated from human nasal swabs in the Philippines.
  
  
  METHODS
  Human nasal swabs were collected from two groups: a low exposure group composed of students of the University of the Philippines-Diliman and a high exposure group composed of laborers frequently exposed to garbage, soil and dust. After isolation using non-nutrient agar plate lawned with Escherichia coli and DNA extraction using Chelex-100 resin, the ASA.S1 region of the gene (Rns) coding for nuclear, small subunit ribosomal RNA of Acanthamoeba was amplified through polymerase chain reaction. Purified polymerase chain reaction products were then sequenced. Neighbor-joining, maximum parsimony, and maximum likelihood phylogenetic trees were then constructed.
  
  
  RESULTS
  In the low exposure group, 1 out of 70 (1.43%) students and 7 out of 110 (6.36%) in the high exposure group were culture-positive. Four soil samples were also obtained for comparison, all of which were tested culture-positive. Of the 12 Acanthamoeba isolates, only 9 were successfully sequenced. The basic local alignment search tool of the US National Center for Biotechnology Information was used to identify most similar sequences. Five isolates were identified as genotype T5, and 3 isolateds were genotype T4. Genotype T11 was also isolated from soil, the first to be reported in the Philippines.
  
  
  CONCLUSIONS
  Genotype T11 is a possible pathogenic strain and both T4 and T5 can be pathogenic to human, hence, healthy provisions, especially for high exposure groups, should be given more attention and reevaluated.
authors.affiliation: Institute of Biology, College of Science, University of the Philippines, Diliman, Quezon City 1101, the Philippines.
authors.forename: Angelo Rafael S
authors.initials: AR
authors.lastname: Cruz
authors.affiliation: Institute of Biology, College of Science, University of the Philippines, Diliman, Quezon City 1101, the Philippines; Molecular Protozoology Laboratory, Natural Sciences Research Institute, University of the Philippines, Diliman, Quezon City 1101, the Philippines. Electronic address: wlrivera@science.upd.edu.ph.
authors.forename: Windell L
authors.initials: WL
authors.lastname: Rivera
keywords: Acanthamoeba; Genotype; Nasal epithelium; The Philippines