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In the province of KwaZulu-Natal, South Africa the incidence of resistant tuberculosis, upper respiratory tract diseases as well as diarrhoeal and parasitic infections is high. Treatment of these diseases with antibiotics is partly reflected by the excretion of the respective antibiotics and their subsequent occurrence in wastewater. Their quantitative reduction in wastewater treatment reflects their potential environmental as well as human impact, the latter due to the use of the recipient water for domestic purposes and for irrigation. Information of the occurrence and reduction of different classes of antibiotics in wastewater treatment is sparse, especially the particle bound fraction of these. Due to this, analyses of aqueous and particle bound antibiotics in untreated wastewater of four selected wastewater treatment plants (WWTPs) and their receiving water bodies was carried out in Durban, South Africa. The treatment step especially considered was the biological one, represented by activated sludge and trickling filters. The treatment further included secondary clarifiers and final chlorine disinfection. Composite samples were collected during the period February 2017 to May 2017 and analysed with online solid phase extraction - high performance liquid chromatography mass spectrometry (SPE-HPLC-MS). For the 13 assessed antibiotics, the limit of detection (LOD) and the limit of quantification (LOQ) ranged from 0.07 to 0.33 ng L -1 and 0.23 to 1.09 ng L -1 respectively, while the total percentage recovery was in the range of 51 to 111%. The percentage of individual antibiotics bound to the particulate fraction normally lost by sample (influent) filtration, if not analysed in parallel, was in the range of 2.6%-97.3% (n = 32). In this fraction (sludge from centrifuge sample), the concentration of bound antibiotics of all the target antibiotics were detected in the influent of all WWTP in concentration ranges between 1.3 ng L -1 (Azithromycin; AZI) to 81,748 ng L -1 (Ciprofloxacin; CIP). The antibiotics with the highest median concentrations in receiving water bodies of the respective WWTP were; Sulfamethoxazole; SUL (239 ng L -1 ) WWTP "K", Ciprofloxacin; CIP (708 ng L -1 ) WWTP "S" and Albendazole; ALB (325 ng L -1 and 683 ng L -1 ) WWTP "P" and "I" respectively. The overall percentage removal efficiency for the four WWTPs ranged from 21% to 100%. The biological treatment steps, activated sludge and trickling filters, were effective in removing antibiotics especially with the trickling filter and the impact of the sedimentation stage after activated sludge treatment., (Copyright © 2019. Published by Elsevier B.V.)

The release and occurrence of antibiotics in the aquatic environment has generated increased attention in the past few decades. The residual antibiotic in wastewater is important in the selection for antimicrobial resistance among microorganisms and the possibility of forming toxic derivatives. This review presents an assessment of the advancement in methods for extraction of antibiotics with solid phase extraction and liquid-liquid extraction methods applied in different aquatic environmental media. These advanced methods do enhance specificity, and also exhibit high accuracy and recovery. The aim of this review is to assess the pros and cons of the methods of extraction towards identification of quinolones and sulphonamides as examples of relevant antibiotics in wastewater. The challenges associated with the improvements are also examined with a view of providing potential perspectives for better extraction and identification protocols in the near future. From the context of this review, magnetic molecular imprinted polymer is superior over the remaining extraction methods (with the availability of commercial templates and monomers), is based on less cumbersome extraction procedures, uses less solvent and has the advantage of its reusable magnetic phase.

The increasing threat to global health posed by antibiotic resistance remains of serious concern. Human health remains at higher risk due to several reported therapeutic failures to many life threatening drug resistant microbial infections. The resultant effects have been prolonged hospital stay, higher cost of alternative therapy, increased mortality, etc. This opinionated review considers the two main concerns in integrated human health risk assessment (i.e., residual antibiotics and antibiotic resistant genes) in various compartments of human environment, as well as clinical dynamics associated with the development and transfer of antibiotic resistance (AR). Contributions of quorum sensing, biofilms, enzyme production, and small colony variants in bacteria, among other factors in soil, water, animal farm and clinical settings were also considered. Every potential factor in environmental and clinical settings that brings about AR needs to be identified for the summative effects in overall resistance. There is a need to embrace coordinated multi-locational approaches and interrelationships to track the emergence of resistance in different niches in soil and water versus the hospital environment. The further integration with advocacy, legislation, enforcement, technological innovations and further research input and recourse to WHO guidelines on antibiotic policy would be advantageous towards addressing the emergence of antibiotic resistant superbugs.