Riverbed Sediments as Reservoirs of Multiple Vibrio cholerae

Africa remains the most cholera stricken continent in the world as many people lacking access to safe drinking water rely mostly on polluted rivers as their main water sources. However, studies in these countries investigating the presence of Vibrio cholerae in aquatic environments have paid little attention to bed sediments. Also, information on the presence of virulence-associated genes (VAGs) in environmental ctx-negative V. cholerae strains in this region is lacking. Thus, we investigated the presence of V. cholerae VAGs in water and riverbed sediment of the Apies River, South Africa. Altogether, 120 samples (60 water and 60 sediment samples) collected from ten sites on the river (January and February 2014) were analysed using PCR. Of the 120 samples, 37 sediment and 31 water samples were positive for at least one of the genes investigated. The haemolysin gene (hlyA) was the most isolated gene. The cholera toxin (ctxAB) and non-O1 heat-stable (stn/sto) genes were not detected. Genes were frequently detected at sites influenced by human activities. Thus, identification of V. cholerae VAGs in sediments suggests the possible presence of V. cholerae and identifies sediments of the Apies River as a reservoir for potentially pathogenic V. cholerae with possible public health implications

Removal of pharmaceutical' estrogenic activity of sequencing batch reactor effluents assessed in the T47D-KBluc report

Various water treatment processes may be ineffective to remove pharmaceutical compounds (PhCs) and their by-products, leading to endocrine-disruptive activity that might be detrimental to wildlife and human health. This study investigated the degradation of carbamazepine (CBZ), diclofenac (DCF), ibuprofen (IBP), and their intermediates, as well as estrogenic activity that is not effectively removed by conventional methods. A consortium of isolated South African indigenous fungi A. niger, M. circinelloides, T. polyzona, T. longibrachiatum and R. microsporus, was used in a sequencing batch reactor (SBR) to remove PhCs, their intermediates and strongly reduce their estrogenic activity. The fungal ligninolytic enzymatic activity was determined for laccase (Lac), manganese peroxidase (MnP) and lignin peroxidase (LiP) using a spectrophotometric method. The biodegradation of PhCs and their intermediates was monitored by SPE-UPLC/MS. The in vitro estrogenic activity was assessed in the T47D-KBluc reporter gene assay. Lac, MnP and LiP production appeared to be biomass growth dependent. During a lag phase of growth, a constant biomass of about 122.04 mg/100 mL was recorded with average enzymatic activity around 63.62 U/L for Lac, 151.91 U/L for MnP and 42.12 U/L for LiP. The exponential growth phase from day 7 to day 17, was characterised by a biomass increase of 124.46 units, and an increase in enzymatic activity of 9.91 units for Lac, 99.03 units for MnP and 44.24 units for LiP. These enzymes played an important synergistic role in PhCs degradation in the cytochrome P450 system. A decrease of 13.89%, 29.7% and 16.15% in PhC concentrations was observed for CBZ, DCF and IBP, respectively, and their intermediates were identified within 4 h of incubation. The removal efficiency achieved after 24 h in the SBR was about 89.77%, 95.8% and 91.41% for CBZ, DCF and IBP, respectively. The estradiol equivalent (EEq) values of 1.71 ± 0.30 ng/L and 2.69 ± 0.17 ng/L were recorded at the start-up time and after 4 h, respectively. The presence of intermediates was found to induce estrogenic activity. The EEq values after 24 h incubation was found to be below the LoQ and below the LoD of the assay. None of the samples exhibited any anti-estrogenic activity. The fungal consortium inoculum was found to induce toxicity at a 0.4× concentration, as observed under a microscope. This study revealed that the use of the fungal consortium can remove the estrogenic activity of pharmaceutical metabolites, which appeared to be the most significant contributors to the endocrine-disrupting activity of the wastewater treatment plant effluents.The Department of Environment, Water and Earth Sciences of the Tshwane University of Technology and grants from the South African National Research Foundation (NRF) through the South African Research Chairs Initiative in Water Quality and Wastewater Management (SARChI, grant number 87310) at the Faculty of Science, Tshwane University of Technology.http://www.elsevier.com/locate/jenvmanhj2020Urolog

Biomass

Due to demands placed on natural resources globally and subsequent deterioration of the environment, there is a need to source and develop appropriate technology to satisfy this requirement. For decades mankind has largely depended on natural resources such as fossil fuels to meet the ever increasing energy demands. Realizing the finite nature of these resources, emphasis is now shifting to investigating alternate energy source governed by environmentally friendly principles. The abundance of biomass and associated favorable techno-economics has recently changed global perceptions of harnessing biomass as a valuable resource rather than a waste. To this end this book aims to make a contribution to exploring further this area of biomass research and development in the form of a compilation of chapters and covering areas of ecological status of different types of biomass and the roles they play in ecosystems, current status of biomass utilization and deriving energy and other value added products from biomass. In this context biomass can be defined as large plants and trees and different groups of microorganisms. This book will serve as an invaluable resource for scientists and environmental managers in planning solutions for sustainable development

Assessing the Sustainability and Acceptance Rate of Cost-Effective Household Water Treatment Systems in Rural Communities of Makwane Village, South Africa

The current study investigated the acceptance rate and long-term effectiveness of cost-effective household water treatment systems deployed in Makwane Village. A structured questionnaire was used prior to implementation to collect information such as level of education, level of employment, and knowledge about point-of-use water treatment systems in the target area. The long-term effectiveness was determined by factors such as the Escherichia coli removal efficiency, turbidity reduction, silver leached, and flow rate of the household water treatment devices. The results of the survey prior to deployment revealed that only 4.3% of the community had a tertiary qualification. Moreover, 54.3% of the community were unemployed. The results further revealed that 65.9% of the community were knowledgeable about other point-of-use water treatment methods. The acceptance rate, which was found to be initially higher (100%), reduced after three months of implantation (biosand filter with zeolite-silver clay granular—82.9%; silver-impregnated porous pot filters—97.1%). Moreover, the long-term effectiveness was determined, taking into consideration the adoption rate, and it was found that silver-impregnated porous pot filters have a long life compared to biosand filter with zeolite-silver clay granular. Although household water treatment systems can effectively reduce the burden of waterborne diseases in impoverished communities, the success of adoption is dependent on the targeted group. This study highlights the significance of involving community members when making the decision to scale up household water treatment devices in rural areas for successful adoption

The Fascinating Cross-Paths of Pathogenic Bacteria, Human and Animal Faecal Sources in Water-Stressed Communities of Vhembe District, South Africa

Access to clean and safe drinking water still remains a major challenge in the developing world, causing public health risks in terms of waterborne infections, especially in rural areas of sub-Saharan Africa. This study aimed to track and detect enteric pathogens (Salmonella enterica subsp. enterica serovar Typhimurium str. LT2, Shigella flexneri, and Campylobacter jejuni subsp. jejuni) in rural water sources. It also sought to establish a correlation between these pathogens and the sources of faecal pollution. Multiplex qPCR and specific primers and probes were used for detection and tracking. The study successfully correlated the occurrence of target pathogens with sources of human and animal faecal contamination using host-specific genetic markers (BacHum and HF183 for humans, BacCow for cows, Pig-2-Bac for pigs, Cytb for chickens, and BacCan for dogs). The study revealed that enteric pathogens were found in 47.69% and 32.80% of samples during the wet and dry seasons, respectively. These pathogens were associated with human or animal faecal contamination. Correlations between pathogens and contamination sources were significant (p ≤ 0.05), with varying strengths during the wet and dry seasons. The findings emphasize the importance of identifying faecal contamination sources to protect rural communities from waterborne infections

An Integrated Approach to Hygiene, Sanitation, and Storage Practices for Improving Microbial Quality of Drinking Water Treated at Point of Use: A Case Study in Makwane Village, South Africa

This study assessed the impact of sanitation practices, hygienic and storage conditions on the quality of drinking water treated at point-of-use in Makwane Village. Subsequent to implementation of low-cost Household Water Treatment Devices which are the biosand filter with zeolite-silver (BSZ-SICG) and silver-impregnated porous pot (SIPP) filters in Makwane village, a structured questionnaire was designed to collect the following information: age of caretakers, number of children under the age of five, water storage conditions, sanitation amenities, and hygiene practices. Water quality from the sources to household level was assessed using culture-based and molecular techniques. The results revealed a significant association between the presence of Escherichia coli in treated drinking water with the age group of caregivers and the number of children ofless than the age of five [OR (95% CI) = 8.4737 (0.147–3.3497), p = 0.0141923 and OR (95% CI) = 9.1667 (0.1848–3.0159); p = 0.0165830, respectively]. Moreover, significant association was noted between hygiene practices (washing of hands with/without soap) and water quality in storage containers [OR (95% CI) = 16.000 (0.6763–3.9495), p = 0.0000125]. These findings further prove that there is still a dire need for reconsidering hygiene education in rural areas as the health benefits of water treated at point of use (POU) coupled with safe-storage condition interventions might not be guaranteed without proper hygiene. The results further highlighted the importance of washing hands in improving microbial quality of drinking water, which is the key factor for fighting against infectious diseases

Prevalence and Molecular Characterisation of Extended-Spectrum Beta-Lactamase-Producing Shiga Toxin-Producing <i>Escherichia coli</i>, from Cattle Farm to Aquatic Environments

Extended-spectrum beta-lactamase (ESBL)-producing bacteria are a major problem for public health worldwide because of limited treatment options. Currently, only limited information is available on ESBL-producing Shiga toxin-producing Escherichia coli (STEC) in cattle farms and the surrounding aquatic environment. This study sought to track and characterise ESBL-producing STEC disseminating from a cattle farm into the water environment. Animal husbandry soil (HS), animal manure (AM), animal drinking water (ADW), and nearby river water (NRW) samples were collected from the cattle farm. Presumptive ESBL-producing STEC were isolated and identified using chromogenic media and mass spectrophotometry methods (MALDI-TOF-MS), respectively. The isolates were subjected to molecular analysis, and all confirmed ESBL-producing STEC isolates were serotyped for their O serogroups and assessed for antibiotic resistance genes (ARGs) and for the presence of selected virulence factors (VFs). A phylogenetic tree based on the multilocus sequences was constructed to determine the relatedness among isolates of ESBL-producing STEC. The highest prevalence of ESBL-producing STEC of 83.33% was observed in HS, followed by ADW with 75%, NRW with 68.75%, and the lowest was observed in AM with 64.58%. Out of 40 randomly selected isolates, 88% (n = 35) belonged to the serogroup O45 and 13% (n = 5) to the serogroup O145. The multilocus sequence typing (MLST) analysis revealed four different sequence types (STs), namely ST10, ST23, ST165, and ST117, and the predominant ST was found to be ST10. All 40 isolates carried sul1 (100%), while blaOXA, blaCTX-M, sul2, blaTEM, and qnrS genes were found in 98%, 93%, 90%, 83%, and 23% of the 40 isolates, respectively. For VFs, only stx2 was detected in ESBL-producing STEC isolates. The results of the present study indicated that a cattle environment is a potential reservoir of ESBL-producing STEC, which may disseminate into the aquatic environment through agricultural runoff, thus polluting water sources. Therefore, continual surveillance of ESBL-producing STEC non-O157 would be beneficial for controlling and preventing STEC-related illnesses originating from livestock environments

Shared Extended-Spectrum β-Lactamase-Producing Salmonella Serovars between Agricultural and Aquatic Environments Revealed through invA Amplicon Sequencing

The presence of antibiotic-resistant Salmonella spp. in the environment is of great public health interest, worldwide. Furthermore, its extended-spectrum &beta;-lactamase (ESBL)-producing strains constitute an emerging global health concern due to their limited treatment options in hospital. Therefore, this study aimed at characterising and tracking nonresistant and ESBL&ndash;producing Salmonella spp. from agricultural settings to nearby water sources highlighting their antibiotic resistance genes (ARG) and virulence factor (VF) distribution using a combination of both culture-dependent and independent methods. Furthermore, this study investigated the diversity and shared serovars among sampled matrices using amplicon sequencing of the invasion gene A (invA) of Salmonella spp. The results showed that soil had the highest prevalence of Salmonella spp. (62.5%, 65/104) and ESBL-producing Salmonella (34.6%, 36/104). For typed ARG, the most commonly detected gene was blaOXA with 75% (30/40), followed by blaCTX-M 67.5% (27/40),blaTEM 40% (16/40) and sul1 30% (12/40) gene; blaSHV gene was not detected in isolated ESBL-producing Salmonella spp. For VF, the most detected gene was invA (96.9%, 38/40), followed by spaM (17.5%, 7/40), spiC (40%, 16/40), orfL (32.5%, 13/40), misL 32.5% (13/40) and pipD 32.5 (13/40). For diversity analysis, soil, manure, irrigation water and nearby freshwater revealed 81, 68, 12 and 9 serovars, respectively. Soil, manure, irrigation water and freshwater stream samples shared five serovars, which indicated circulation of ESBL-producing Salmonella spp. within the agricultural environment and nearby water sources. Soil is therefore identified as one of the major reservoirs of ESBL-producing Salmonella spp. It is concluded that agricultural environment contamination may have a direct relationship with the presence of antibiotic-producing Salmonella in freshwater streams

Genetic characterization of Salmonella and Shigella spp. isolates recovered from water and riverbed sediment of the Apies River, South Africa

Riverbed sediment is a vital component of river ecosystems and plays an important role in many geomorphological and ecological processes. However, when re-suspension occurs, pathogenic bacteria associated with sediment particles may be released into the water column, thus creating a health risk to those who use such water for drinking, household and recreational purposes. The aim of this study was to investigate the presence of bacterial pathogens Salmonella spp. and Shigella spp. in the Apies River and to ascertain whether there was any level of genetic relatedness between river water and riverbed sediment isolates of these pathogenic bacteria. A total of 124 water and sediment samples were collected from a site located on the Apies Rivers upstream of the Daspoort Wastewater Treatment Works, Pretoria, Gauteng, South Africa, between August and November 2014. In order to detect and identify the target bacteria, samples were analysed by culture-dependent and culture-independent techniques (quantitative real-time PCR). Genetic relatedness was established using Sanger sequencing of the invA gene of Salmonella spp. and ipaH of Shigella spp. Results of this study displayed the presence of the target bacteria both in the water and sediment of the river. The phylogenetic tree of Salmonella spp. revealed a ≥ 99% and 99% genetic relatedness between river water and riverbed sediment isolates for Salmonella spp. and Shigella spp., respectively. The degree of genetic relatedness between sediment and water pathogen isolates suggests that these organisms could possibly have a common origin and that there could be possible movement of microorganisms between the water column and the sediments.Keywords: Salmonella spp., Shigella spp., river water, riverbed sediment, genetic relatednes