title: FRNA Bacteriophages as Viral Indicators of Faecal Contamination in Mexican Tropical Aquatic Systems.
abstract: A particular challenge to water safety in populous intertropical regions is the lack of reliable faecal indicators to detect microbiological contamination of water, while the numerical relationships of specific viral indicators remain largely unexplored. The aim of this study was to investigate the numerical relationships of FRNA-bacteriophage genotypes, adenovirus 41, and human adenoviruses (HADV) in Mexican surface water systems to assess sewage contamination. We studied the presence of HADV, HADV41 and FRNA bacteriophage genotypes in water samples and quantified by qPCR and RT-qPCR. Virus and water quality indicator variances, as analyzed by principal component analysis and partial least squared regression, followed along the major percentiles of water faecal enterococci. FRNA bacteriophages adequately deciphered viral and point source water contamination. The strongest correlation for HADV was with FRNA bacteriophage type II, in water samples higher than the 50th percentiles of faecal enterococci, thus indicating urban pollution. FRNA bacteriophage genotypes I and III virus indicator performances were assisted by their associations with electrical conductivity and faecal enterococci. In combination, our methods are useful for inferring water quality degradation caused by sewage contamination. The methods used have potential for determining source contamination in water and, specifically, the presence of enteric viruses where clean and contaminated water have mixed.
authors.affiliation: Laboratorio Nacional de Ciencias de la Sostenibilidad, Instituto de Ecología, Universidad Nacional Autónoma de México, Mexico City, Mexico.
authors.forename: Luis Jose Rene
authors.identifier: http://orcid.org/0000-0002-1631-8713
authors.initials: LJ
authors.lastname: Arredondo-Hernandez
authors.affiliation: Departamento de Probabilidad y Estadística, Instituto de Investigaciones en Matemáticas Aplicadas y en Sistemas, Universidad Nacional Autónoma de México, Mexico City, Mexico.
authors.forename: Carlos
authors.initials: C
authors.lastname: Diaz-Avalos
authors.affiliation: Programa de Inmunología Molecular Microbiana, Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico.
authors.forename: Yolanda
authors.initials: Y
authors.lastname: Lopez-Vidal
authors.affiliation: Programa de Inmunología Molecular Microbiana, Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad Nacional Autónoma de México, Mexico City, Mexico.
authors.forename: Gonzalo
authors.initials: G
authors.lastname: Castillo-Rojas
authors.affiliation: Laboratorio Nacional de Ciencias de la Sostenibilidad, Instituto de Ecología, Universidad Nacional Autónoma de México, Mexico City, Mexico.
authors.forename: Marisa
authors.initials: M
authors.lastname: Mazari-Hiriart
mesh_terms: D001435:Bacteriophages / Q000235:genetics / Q000302:isolation & purification*; D005243:Feces / Q000821:virology*; D006801:Humans; D008800:Mexico; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014871:Water Microbiology