Antibiotic resistance in environmental Escherichia coli – a simple screening method for simultaneous typing and resistance determination

Abstract

We describe a simple and standardised screening system (AREB) for surveillance of antibiotic resistant bacteria in the environment. The system consists of 96 well microplates containing eight sets of breakpoint amounts of 10 different antibiotics. The incubated microplates are read by a desktop scanner and the plate images are analysed by special software that automatically presents the resistance data. The AREB method is combined with a rapid typing method, the PhenePlate system, which yields information on the diversity of the bacteria in the studied samples, and on the possible prevalence of resistant clones. In order to demonstrate the usage of AREB, a comparative study on the resistance situation among 970 Escherichia coli isolates from sewage and recipient water in Sweden, Norway and Chile, was performed. Resistance rates to all antibiotics were markedly higher in hospital sewage than in other samples. Our data indicate that the AREB system is useful for comparing resistance rates among E. coli and other environmental indicator bacteria in different countries/regions. Simple handling and automatic data evaluation, combined with low cost, facilitate large studies involving several thousands of isolates.

Population-level surveillance of antibiotic resistance in Escherichia coli through sewage analysis

“…Biochemical fingerprinting of sewage isolates strongly supported this hypothesis by revealing a reduced diversity of the E. coli isolated from hospital sewage samples showing extreme resistance patterns. A similar range of E. coli diversity in hospital wastewater has been shown in studies by Kwak et al and Colque Navarro et al [15,30]. Analogous to the current study, low diversity found in a hospital wastewater sample could be attributed to the presence of highly abundant biochemical phenotypes with the same resistance pattern [30].…”

“…A similar range of E. coli diversity in hospital wastewater has been shown in studies by Kwak et al and Colque Navarro et al [15,30]. Analogous to the current study, low diversity found in a hospital wastewater sample could be attributed to the presence of highly abundant biochemical phenotypes with the same resistance pattern [30]. Limited diversity due to clonality emphasises the necessity for repeated sampling of sewage in order to obtain representative data, especially when hospital sewage is collected.…”

Repeated Isolation of Extended-Spectrum-β-Lactamase-Positive Escherichia coli Sequence Types 648 and 131 from Community Wastewater Indicates that Sewage Systems Are Important Sources of Emerging Clones of Antibiotic-Resistant Bacteria

“…Up to 80 E. coli-like colonies were collected from each daily sample and subjected to PhenePlate (PhP) typing (PhPlate AB) (5, 35). The PhP system quantifies fermentation patterns for each isolate by assigning numerical values to each carbohydrate source (in 96-plate wells) as a discrete value on a scale from completely negative (25) to completely positive (0), respectively.…”

“…The colonies were simultaneously analyzed for resistance to nine antibiotics with the AREB microplates (5, 35). In total, 3,123 isolates of E.…”

“…Therefore, WWSs might represent a suitable interface for the surveillance of infectious bacteria and the presence of bacteria carrying ARGs. In addition, if properly collected, WWS samples provide a reliable representation of the large variability of bacteria circulating in large populations connected to the wastewater treatment plant or in individual sewage (4–6). Several studies have suggested an association between the presence of enteric pathogens in WWSs and active disease in the community (2, 7).…”