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Monitoring effluents from wastewater treatment plants is important to preventing both environmental contamination and the spread of disease. We evaluated the occurrence of human enteric bacteria (faecal coliforms and Escherichia coli) and viruses (rotavirus and enterovirus) in the final effluents of five wastewater treatment plants (WWTPs) in the Eastern Cape of South Africa. Human viruses were recovered from the effluent samples with the adsorption-elution method and detected with singleplex real-time RT-PCR assays. Rotavirus was detected in several effluents samples, but no enterovirus was detected. At WWTP-C, rotavirus titre up to 10 5 genome copies/L was observed and present in 41.7% of the samples. At WWTP-B, the virus was detected in 41.7% of samples, with viral titres up to 10 3 genome copies/L. The virus was detected once at WWTP-E, in 9% of the samples analysed. The viral titres at WWTP-A were below the detection limit in all 25% of the 1.25L samples in which the virus was detected. Rotavirus was not observed at WWTP-D. Faecal coliform bacteria and E. coli were detected in all the WWTPs, but no correlation was established between the enteric bacteria and viruses studied. The occurrence of rotavirus in effluent samples discharged into surface waters highlights the importance of assessing viral contamination in the water sources used for domestic water use., (Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.)

The final effluents of two wastewater treatment plants (WWTPs) in the Eastern Cape Province of South Africa were evaluated for their physicochemical and microbiological qualities over a period of 12 months. The physicochemical parameters assessed ranged as follows both plants. The ranges of values for the physicochemical are: pH (3.9-8.6), total dissolved solids (86.50-336.3 mg/L), electrical conductivity (13.57-52.50 mS/m), temperature (13-28 °C), nitrate (0-21.73 mg/L), nitrite (0.01-0.60 mg/L), orthophosphate (1.29-20.57 mg/L), turbidity (4.02-43.20 NTU), free chlorine (0.05-7.18 mg/L), dissolve oxygen (3.91-9.60 mg/L), biochemical oxygen demand (0.1-9.0 mg/L) and chemical oxygen demand (4.67-211 mg/L). The microbiological assessment for both WWTPs revealed the presence of E. coli in counts ranging between 0 and 1.86 × 10⁴ CFU/100 mL and Vibrio counts ranging between 0 and 9.93 × 10³ CFU/100 mL. We conclude that these WWTPs are important point sources of pollution in surface water with potential public health and ecological risks.

Background: Municipal effluent constitutes a large reservoir of human enteric viruses and bacteria. Contemporary monitoring practices rely on indicator bacteria, and do not test for viruses. Different viruses, including Norwalk-like viruses, Hepatitis A virus (HAV), adenoviruses, and rotaviruses, are important agents of illnesses in humans. The burden of disease caused by adenoviruses manifests as pneumonia, bronchiolitis, otitis media, conjunctivitis, and tonsillitis, whereas HAV infection can manifest as acute inflammatory diseases of the liver, fever, anorexia, malaise, nausea, and abdominal discomfort, followed by jaundice and dark urine. The public health implications of these viruses depend upon the physiological status of the wastewater microbial community., Methods: The occurrence of human adenovirus (HAdV) and HAV was determined in the final effluents of five wastewater treatment plants (WWTPs) in the Eastern Cape, South Africa, over 12 months (September 2012-August 2013). The viruses were detected with real-time PCR, and conventional PCR was used for serotyping., Results: Adenovirus was detected in effluent samples from all five WWTPs and in 64 % of the total samples, whereas HAV was not detected in any effluent sample. At WWPT-A, samples were collected from the final effluent tank (adenoviral concentrations ranged from 1.05 × 10(1) to 1.10 × 10(4) genome/L, with a 41.7 % detection rate) and the discharge point (adenoviral concentrations ranged between 1.2 × 10(1) and 2.8 × 10(4) genome/L, with a 54.5 % detection rate). At WWPT-B, HAdV was detected in 91.7 % of samples, with viral concentrations of 7.92 × 10(1)-2.37 × 10(5) genome/L. The HAdV concentrations at WWPT-C were 5.32 × 10(1)-2.20 × 10(5) genome/L, and the detection rate was 75 %. The adenoviral concentrations at WWPT-D were 1.23 × 10(3)-1.05 × 10(4) genome/L, and the detection rate was 66.7 %. At WWPT-E, the viral concentrations were 1.08 × 10(1)-5.16 × 10(4) genome/L, and the detection rate was 54.5 %. Characterization of the adenoviruses revealed HAdV serotypes 2 (1.4 %) and 41 (7.1 %), in species C and F, respectively., Conclusions: This study is the first to report the prevalence of HAdV in the final effluents of WWTPs in the Eastern Cape, South Africa. The adenoviral detection rates indicate the potential contamination of the environment, with adverse effects on public health.

Vibrios and other enteric pathogens can be found in wastewater effluents of a healthy population. We assessed the prevalence of three non-cholerae vibrios in wastewater effluents of 14 wastewater treatment plants (WWTP) in Chris Hani and Amathole district municipalities in the Eastern Cape Province of South Africa for a period of 12 months. With the exception of WWTP10 where presumptive vibrios were not detected in summer and spring, presumptive vibrios were detected in all seasons in other WWTP effluents. When a sample of 1,000 presumptive Vibrio isolates taken from across all sampling sites were subjected to molecular confirmation for Vibrio, 668 were confirmed to belong to the genus Vibrio, giving a prevalence rate of 66.8 %. Further, molecular characterisation of 300 confirmed Vibrio isolates revealed that 11.6 % (35) were Vibrio parahaemolyticus, 28.6 % (86) were Vibrio fluvialis and 28 % (84) were Vibrio vulnificus while 31.8 % (95) belonged to other Vibrio spp. not assayed for in this study. Antibiogram profiling of the three Vibrio species showed that V. parahaemolyticus was ≥50 % susceptible to 8 of the test antibiotics and ≥50 % resistant to only 5 of the 13 test antibiotics, while V. vulnificus showed a susceptibility profile of ≥50 % to 7 of the test antibiotics and a resistance profile of ≥50 % to 6 of the 13 test antibiotics. V. fluvialis showed ≥50 % resistance to 8 of the 13 antibiotics used while showing ≥50 % susceptibility to only 4 antibiotics used. All three Vibrio species were susceptible to gentamycin, cefuroxime, meropenem and imipenem. Multiple antibiotic resistance patterns were also evident especially against such antibiotics as tetracyclin, polymixin B, penicillin G, sulfamethazole and erythromycin against which all Vibrio species were resistant. These results indicate a significant threat to public health, more so in the Eastern Cape Province of South Africa which is characterised by widespread poverty, with more than a third of the population directly relying on surface water sources for drinking and daily use.

The final effluents of two wastewater plants located in the Eastern Cape of South Africa were tested for the presence of enterohaemorrhagic Escherichia coli O157:H7 isolates, and characteristics of the isolates obtained were determined. A total of 23 wastewater samples were collected from the treatment plants at the final effluent point after the disinfectant stages of wastewater processing. Altogether, 540 presumptive E. coli isolates were obtained by colony counting on the E. coli O157:H7 chromogenic agar base supplemented with cefixime tellurite and were subcultured onto sorbitol-MacConkey agar and tested for agglutination using the Prolex E. coli O157 latex test reagent kit. The results showed that the 149 suspected colonies from SMAC agar were all negative for the antisera. None of the isolates agglutinated with antisera against E. coli O157 and thus no presence of the bacteria can be confirmed from the treated effluents. The likelihood of the receiving water body and the environment being contaminated with E. coli O157:H7 is therefore minimal. Future monitoring is however recommended. [ABSTRACT FROM AUTHOR]