Abundance and Antimicrobial Resistance of Three Bacterial Species along a Complete Wastewater Pathway

Abstract

After consumption, antibiotic residues and exposed bacteria end up via the feces in wastewater, and therefore wastewater is believed to play an important role in the spread of antimicrobial resistance (AMR). We investigated the abundance and AMR profiles of three different species over a complete wastewater pathway during a one-year sampling campaign, as well as including antimicrobial consumption and antimicrobial concentrations analysis. A total of 2886 isolates (997 Escherichia coli, 863 Klebsiella spp., and 1026 Aeromonas spp.) were cultured from the 211 samples collected. The bacterial AMR profiles mirrored the antimicrobial consumption in the respective locations, which were highest in the hospital. However, the contribution of hospital wastewater to AMR found in the wastewater treatment plant (WWTP) was below 10% for all antimicrobials tested. We found high concentrations (7–8 logs CFU/L) of the three bacterial species in all wastewaters, and they survived the wastewater treatment (effluent concentrations were around 5 log CFU/L), showing an increase of E. coli in the receiving river after the WWTP discharge. Although the WWTP had no effect on the proportion of AMR, bacterial species and antimicrobial residues were still measured in the effluent, showing the role of wastewater contamination in the environmental surface water.

Effects of tourist flows on antibiotic resistance in wastewater of a Greek island

“…2013; Verburg et al . 2019). Accordingly, resistance profiles of all four species showed no difference before and after treatment, in most of the cases, with the exception of tetracycline‐resistant enterococci.…”

“…2013; Verburg et al . 2019). Particular concern is caused by extended‐spectrum beta‐lactamase‐producing organisms (ESBL), methicillin‐resistant Staphylococcus aureus species (MRSA) and vancomycin‐resistant Enterococcus sp.…”

Effects of Clinical Wastewater on the Bacterial Community Structure from Sewage to the Environment

“…Further investigation is necessary to determine whether such variations may be caused by the influence of other wastewater sources and rain events, which fluctuate throughout the year. use of antibiotics and other drugs in the clinical settings [12]. Only one other study reported a direct comparison between hospital wastewater, domestic wastewater and influent [40], and showed that these three waters were contained in the same cluster, with domestic wastewater more similar to hospital wastewater than to influent.…”

“…Such, and other, pathogenic bacteria are expected to be more abundant in clinical settings, where the consumption of antibiotics is higher than in the general community [ 11 ]. Previous research showed that clinical wastewaters contain a higher level of AMR bacteria, antimicrobial resistance genes and antimicrobial residues than non-clinical wastewaters [ 12 , 13 , 14 , 15 ]. Nonetheless, clinical wastewater constitutes a minor proportion of all wastewater and the magnitude of the impact that clinical wastewater has on AMR bacterial load in downstream wastewaters is not yet fully understood.…”

Treatment Processes for Microbial Resistance Mitigation: The Technological Contribution to Tackle the Problem of Antibiotic Resistance

“…As both water and land can be directly affected by industrial, municipal, or agricultural activities, other factors promote selective pressure and enable the amplification, maintenance, and spread of ARB. Moreover, in the wastewater treatment plants (WWTPs), the place where the elimination of chemical and biological pollutants should be eliminated, the environmental conditions such as the presence of metals, pesticides, and abundance of microorganisms promote antimicrobial resistance in a larger number of bacteria or microorganisms by selective pressure [39][40][41]. Table 1 shows a shortlist of several antibiotic-resistant microorganisms that have been found in wastewater treatment plants.…”