Antibiotic-resistant genes and antibiotic-resistant bacteria in the effluent of urban residential areas, hospitals, and a municipal wastewater treatment plant system

Abstract

In this study, we determined the abundance of 8 antibiotics (3 tetracyclines, 4 sulfonamides, and 1 trimethoprim), 12 antibiotic-resistant genes (10 tet, 2 sul), 4 antibiotic-resistant bacteria (tetracycline, sulfamethoxazole, and combined resistance), and class 1 integron integrase gene (intI1) in the effluent of residential areas, hospitals, and municipal wastewater treatment plant (WWTP) systems. The concentrations of total/individual targets (antibiotics, genes, and bacteria) varied remarkably among different samples, but the hospital samples generally had a lower abundance than the residential area samples. The WWTP demonstrated removal efficiencies of 50.8% tetracyclines, 66.8% sulfonamides, 0.5 logs to 2.5 logs tet genes, and less than 1 log of sul and intI1 genes, as well as 0.5 log to 1 log removal for target bacteria. Except for the total tetracycline concentration and the proportion of tetracycline-resistant bacteria (R (2) = 0.330, P < 0.05), there was no significant correlation between antibiotics and the corresponding resistant bacteria (P > 0.05). In contrast, various relationships were identified between antibiotics and antibiotic resistance genes (P < 0.05). Tet (A) and tet (B) displayed noticeable relationships with both tetracycline and combined antibiotic-resistant bacteria (P < 0.01).

Occurrences and Characterization of Antibiotic-Resistant Bacteria and Genetic Determinants of Hospital Wastewater in a Tropical Country

“…Wastewater discharge from clinical isolation wards housing patients recovering from severe infections tends to harbor higher levels of ARB detection. In this study, the average level of intI1 genes detected was at least 2 orders of magnitude lower than that detected in hospital wastewaters in China, with tet and sul genes detected in a lower range as well (37). Class 1 integrons are responsible for the spread and carriage of antibiotic resistance gene cassettes in Gram-negative pathogens (38,39).…”

Occurrence, Distribution, and Risk Assessment of Antibiotics in a Subtropical River-Reservoir System

“…In addition, it has been reported that antibiotics could only be partially metabolized by humans or animals [3]. Then, active substances associated with the antibiotics pass through artificial environments, and may end up in different environmental compartments including water, sediment, and soil, attributed to the fact that most of these chemicals are water soluble and not susceptible to degradation and transformation [6][7][8]. Consequently, it is inevitable that environmental organisms are more or less exposed to these compounds, which are still active with ecotoxic effects even in a very low concentration.…”

The Antibiotic Resistance by Bacteria Forming Biofilm into Water Pipes

“…On the other hand, water distribution systems are places where bacteria remain viable for a long time; there bacteria can to exchange genetic material and it provides resistance to antibiotics (Armstrong et al, 1981;Li et al, 2015). In this context it has been common to find reports regarding the presence of antibiotics in wastewater, water from treatment plants or river water (Li et al, 2015;Martínez et al, 2010).…”

“…In this context it has been common to find reports regarding the presence of antibiotics in wastewater, water from treatment plants or river water (Li et al, 2015;Martínez et al, 2010). However, in recent years it has been of interest to notice the presence of bacteria in drinking water pipes, especially bacteria that are resistant to different antibiotics.…”