High prevalence of multidrug-resistant Escherichia coli and Enterococcus spp. in river water, upstream and downstream of a wastewater treatment plant

Abstract

In this study, microbial quality and antimicrobial resistance of faecal bacteria from a Portuguese river were assessed. River water samples collected upstream and downstream of a wastewater treatment plant, throughout a 3-month period, were used for the enumeration of Escherichia coli and Enterococcus spp. The highest numbers found for E. coli and enterococci were 1.1 × 10⁴ and 1.2 × 10⁴ colony forming units (CFU)/100 ml, respectively. In total, 144 isolates of E. coli and 144 of enterococci were recovered and tested for antimicrobial susceptibility; 104 E. coli and 78 Enterococcus spp. showed resistance to one or more antimicrobial drugs. Overall, 70 and 32 different resistance patterns were found for E. coli and enterococci, respectively. One E. coli showed resistance to imipenem and 29 isolates were extended spectrum β-lactamase-producers. Multidrug-resistant E. coli belonged mostly to groups A, B1 and group D. Enterococcus spp. were mostly resistant to rifampicin, tetracycline, azithromycin and erythromycin; six isolates showed resistance to vancomycin, presenting the VanA phenotype. The high levels of E. coli and enterococci and the remarkable variety of antimicrobial resistance profiles, reinforces the theory that these river waters can be a pool of antimicrobial resistance determinants, which can be easily spread among different bacteria and reach other environments and hosts.

A New Dihydrochromone Dimer and Other Secondary Metabolites from Cultures of the Marine Sponge-Associated Fungi Neosartorya fennelliae KUFA 0811 and Neosartorya tsunodae KUFC 9213

“…For reference, a clinical isolate sensitive to the most commonly used antibiotic families, and four multidrug-resistant bacterial strains were used in this study. The Gram-positive bacteria comprised Staphylococcus aureus ATCC 29213, Enterococcus faecalis ATCC 29212, a clinical isolate S. aureus 40/61/24, MRSA S. aureus 66/1 isolated from public buses [ 35 ], and VRE E. faecalis A5/102 and VRE E. faecalis B3/101 isolated from river water [ 36 ]. The Gram-negative bacteria used were Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853, and a clinical isolate ESBL E. coli SA/2.…”

Chromone Derivatives and Other Constituents from Cultures of the Marine Sponge-Associated Fungus Penicillium erubescens KUFA0220 and Their Antibacterial Activity

“…Gram-positive bacteria included Staphylococcus aureus ATCC 29213, Enterococcus faecium ATCC 19434, Enterococcus faecalis ATCC 29212, methicillin-resistant Staphylococcus aureus (MRSA) 66/1 isolated from public buses [28], and vancomycin-resistant enterococci (VRE) Enterococcus faecium 1/6/63 and Enterococcus faecalis B3/101 isolated from river water [29]. Gram-negative strains comprised Escherichia coli ATCC 25922, Pseudomonas aeruginosa ATCC 27853 and the clinical isolate SA/2, an extended-spectrum β-lactamase producer (ESBL).…”

Water research in Germany: from the reconstruction of the Roman Rhine to a risk assessment for aquatic neophytes

“…This is problematic when water bodies are used as a source for drinking or irrigation water, or when water bodies are used for water sports. Moreover, rivers are relevant as pathways for the transport of pathogenic microorganisms Reder et al 2015), including antibiotic-resistant bacteria which originate from wastewater inputs which contain antibiotics and their metabolites (Bessa et al 2014;Schreiber and Kistemann 2013). In aquatic ecosystems, there can even be interactions between different pollutants.…”