Fate and persistence of antibiotic-resistant bacteria and genes through a multi-barrier treatment facility for direct potable reuse

Abstract

Given the availability of technological solutions and guidelines for safe drinking water, direct potable reuse of reclaimed water has become a promising option to overcome severe lack of potable water in arid regions. However, the growing awareness of the presence of antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARG) in corresponding raw wastes has led to new safety concerns. This study investigated the fate of ARB and intracellular and extracellular ARG after each treatment step of an advanced water treatment facility in Windhoek, Namibia. The New Goreangab Water Reclamation Plant (NGWRP) produces drinking water from domestic secondary wastewater treatment plant effluent and directly provides for roughly a quarter of Windhoek's potable water demand. Procedures to study resistance determinants were based on both, molecular biology and culture-based microbiological methods. TaqMan real-time PCR was employed to detect and quantify intracellular resistance genes sul1, ermB, vanA, nptII and nptIII as well as extracellular resistance gene sul1. The NGWRP reduced the amount of both culturable bacterial indicators as well as the resistance genes to levels below the limit of detection in the final product. The main ozonation and the ultrafiltration had the highest removal efficiencies on both resistance determinants.

Tracing Antibiotic Resistance Genes along the Irrigation Water Chain to Chive: Does Tap or Surface Water Make a Difference?

“…Other sterilization methods, such as UV-treatment, have been reported to increase total relative abundance of ARGs in wastewater [ 30 ]. On the other hand, ultrafiltration has been shown to have very high ARB and ARG removal efficiencies [ 31 , 32 ], which is, however, more efficient than the filters used in our study.…”

Inactivation of antibiotic-resistant bacteria and antibiotic-resistance genes in wastewater streams: Current challenges and future perspectives

“…The RNA methyltransferase, ermB , which is located on the transposon ( Pazda et al, 2019 ; Wallmann et al, 2021 ), is prevalent in Gram-positive enterococci and it confers resistance to critically important macrolide-lincosamine-streptogramin (MLS) antibiotics like erythromycin, azithromycin and clarithromycin ( Wallmann et al, 2021 ). The ermB genes are present in China (WWTP1, WWWP2), Namibia (NGWRP), United States (WRPF) and Germany (WWTP5; Table 1 ).…”

“…Sulfonamides are widely used in veterinary medicine as feed additives and the treatment of bacteria but in humans they are usually used in combination with trimethoprim for chlamydia, respiratory and urinary tract infections ( Hendricks and Pool, 2012 ; Pazda et al, 2019 ). Sul1 is a resistant dihydropteroate synthase which mediates tolerance to a broad group of sulfonamide antibiotics ( Wallmann et al, 2021 ). This gene is frequently found in both transposons and plasmids of Gram-negative enterobacteria but also in environmental pathogens like Pseudomonas aeruginosa ( Pazda et al, 2019 ; Wallmann et al, 2021 ).…”

Photodegradation of biobased polymer blends in seawater: A major source of microplastics in the marine environment

“…Although MPs derived from PLA/PBAT/TPS do biodegrade, they are relatively less biodegradable in the marine environment because their biodegradation is triggered in composting conditions with high temperatures or abundant microorganisms (Narancic et al, 2018). Moreover, photodegradation causes changes in the physicochemical properties of MPs derived from biobased polymer blends and affects their fate in the ocean (Wallmann et al, 2021;Luo et al, 2022b). For example, photodegradation can decrease the hydrophilicity of PP/TPS and increase its negative surface charge.…”