Ubiquitous and persistent Proteobacteria and other Gram-negative bacteria in drinking water

• Type: Article in International Scientific Journal
• Date: 2017

Authors

Ivone Vaz Moreira (Author) FEUP; Olga C. Nunes (Author) FEUP; Célia M. Manaia (Author) Other

Journal

Title: Science of the Total Environment

Vol. 586

Pages: 1141-1149

ISSN: 0048-9697

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 13 Citations

Scopus - 46 Citations

Associated Projects

LEPABE - Laboratório de Engenharia de Processos, Ambiente, Biotecnologia e Energia

Other information

Authenticus ID: P-00M-G2T

DOI: 10.1016/j.scitotenv.2017.02.104

Abstract (EN): Drinking water comprises a complex microbiota, in part shaped by the disinfection and distribution systems. Gram-negative bacteria, mainly members of the phylum Proteobacteria, represent the most frequent bacteria in drinking water, and their ubiquity and physiological versatility raises questions about possible implications in human health. The first step to address this concern is the identification and characterization of such bacteria that is the first objective of this study, aiming at identifying ubiquitous or persistent Gram-negative bacteria, Proteobacteria or members of other phyla, isolated from tap water or from its source. > 1000 bacterial isolates were characterized and identified, and a selected group (n = 68) was further analyzed for the minimum inhibitory concentrations (MIC) to antibiotics (amoxicillin and gentamicin) and metals (copper and arsenite). Total DNA extracts of tap water were examined for the presence of putatively acquired antibiotic resistance or related genes (intI1, blaTEM, qnrS and sul1). The ubiquitous tap water genera comprised Proteobacteria of the class Alpha- (Blastomonas, Brevundimonas, Methylobacterium, Sphingobium, Sphingomonas), Beta- (Acidovorax, Ralstonia) and Gamma- (Acinetobacter and Pseudomonas). Persistent species were members of genera such as Aeromonas, Enterobacter or Dechloromonas. Ralstonia spp. showed the highest MIC values to gentamicin and Acinetobacter spp. to arsenite. The genes intI1, blaTEM or sul1 were detected, at densities lower than 2.3 × 105 copies/L, 2.4 × 104 copies/L and 4.6 × 102 copies/L, respectively, in most tap water samples. The presence of some bacterial groups, in particular of Beta- or Gammaproteobacteria (e.g. Ralstonia, Acinetobacter, Pseudomonas) in drinking water may deserve attention given their potential as reservoirs or carriers of resistance or as opportunistic pathogens. © 2017 Elsevier B.V.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 9