Publication:
Probing for clinical integrons and integron-encoded antibiotic resistance genes as molecular Indicators of wastewater-related degradation of subtropical coastal environments

dc.contributor.advisor Rodríguez-Minguela, Carlos M.
dc.contributor.author Alvarez-Pérez, Odalys S.
dc.contributor.college College of Arts and Sciences - Sciences en_US
dc.contributor.committee Montalvo Rodríguez, Rafael
dc.contributor.committee Maldonado Ramírez, Sandra L.
dc.contributor.department Department of Biology en_US
dc.contributor.representative Navarro, Ana
dc.date.accessioned 2018-05-16T13:47:57Z
dc.date.available 2018-05-16T13:47:57Z
dc.date.issued 2011
dc.description.abstract Wastewater discharges comprise the main source of fecal contamination across coastal environments in Puerto Rico. Enteric bacteria from hospital settings are frequently key hosts of integrons, a genetic system encoding multiple antibiotic resistance (ABR) genes. Nevertheless, it is unknown if bacterial hosts of integrons loaded with antibiotic resistance genes could become established across local coastal habitats. Using PCR and DNA sequencing analyses, prevalence patterns of integron integrases (classes 1, 2 and 3) and class 1-encoded ABR genes were detected in DNA samples recovered from wastewater-contaminated mangrove, beach and estuarine environments. Bacteriological analyses of mangrove ecosystems revealed that sediments and the rhizosphere are significant reservoirs of fecal bacteria (enterococci and fecal coliforms). Six different integron-encoded ABR genes were detected across impacted sites. These were related to determinants conferring resistance against four antimicrobial agents (aminoglycosides, trimethoprim, chloramphenicol and third generation cephalosporins) used for the treatment of infections of the urinary, respiratory and digestive tract in humans. Genes encoding resistance against disinfectants widely used in hospitals (quaternary ammonium compounds) were also detected. Genes encoding resistance against cephalosporins were specifically detected in wastewater-impacted mangrove and esturarine ecosystems. This study revealed that wastewatercontaminated coastal habitats are reservoirs of bacteria carrying ABR genes and that integrons may serve as indicators of fecal contamination and potential health risks at impacted sites.
dc.description.abstract Las descargas de aguas residuales constituyen la principal fuente de contaminación de origen fecal en los ambientes costeros de Puerto Rico. Las bacterias fecales aisladas en ambientes de hospitales frecuentemente son portadoras de integrones, un sistema genético que codifica múltiples mecanismos de resistencia a antibióticos (RAB). Sin embargo, se desconoce si bacterias con integrones cargados con genes de resistencia, pudieran establecerse en ambientes costeros expuestos a contaminación fecal. Utilizando la reacción en cadena de la polimerasa (PCR) y análisis de secuenciación de ADN, se detectaron patrones de prevalencia de integrasas de integrones (clases 1, 2 y 3) y genes de RAB codificados por integrones clase 1, en ADN de muestras ambientales tomadas en manglares, playas y estuarios contaminados por aguas residuales. Los análisis bacteriológicos de ecosistemas de mangle revelaron que los sedimentos y la rizósfera constituyen reservorios importantes de bacterias fecales tales como enterococos y coliformes fecales. Seis genes diferentes de RAB codificados por integrones clase 1 fueron detectados en ambientes impactados. Estos estaban relacionados a mecanismos que confieren resistencia contra cuatro agentes antimicrobianos (aminoglucósidos, trimetoprima, cloramfenicol, y cefalosporinas de tercera generación) usados para el tratamiento de infecciones del tracto respiratorio, urinario y digestivo en humanos. También se detectaron genes codificantes para resistencia a desinfectantes utilizados en hospitales (compuestos de amonio cuaternario). Los genes codificantes para resistencia en contra de cefalosporinas se detectaron en asociación con un manglar y un estuario impactado por aguas usadas. Este estudio reveló que hábitats costeros degradados por aguas usadas son reservorios de bacterias con genes de resistencia a antibióticos y que los integrones podrían servir como indicadores de contaminación fecal y riesgos a la salud en ambientes costeros.
dc.description.graduationSemester Fall en_US
dc.description.graduationYear 2011 en_US
dc.description.sponsorship The Sea Grant Program (Project R-92-3-08) en_US
dc.identifier.uri https://hdl.handle.net/20.500.11801/473
dc.language.iso en en_US
dc.rights.holder (c) 2011 Odalys S. Alvarez Pérez en_US
dc.rights.license All rights reserved en_US
dc.subject Integrons en_US
dc.subject Antibiotic resistance traits en_US
dc.subject Coastal habitats impacted by sewage-related pollution en_US
dc.subject.lcsh Sewage--Microbiology--Puerto Rico--Coasts en_US
dc.subject.lcsh Sewage--Environmental aspects--Puerto Rico--Coasts en_US
dc.subject.lcsh Enterobacteriaceae--Puerto Rico--Coasts en_US
dc.subject.lcsh Microbial contamination--Puerto Rico--Coasts en_US
dc.title Probing for clinical integrons and integron-encoded antibiotic resistance genes as molecular Indicators of wastewater-related degradation of subtropical coastal environments en_US
dc.type Thesis en_US
dspace.entity.type Publication
thesis.degree.discipline Biology en_US
thesis.degree.level M.S. en_US
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