Competitive Survival of Escherichia coli, Vibrio cholerae, Salmonella typhimurium and Shigella dysenteriae in Riverbed Sediments

Abstract

Studies on the survival of bacterial enteric pathogens in riverbed sediments have mostly focused on individual organisms. Reports on the competitive survival of these pathogens in riverbed sediments under the same experimental setup are limited. We investigated the survival of Escherichia coli, Salmonella enterica ser. Typhimurium, Vibrio cholerae and Shigella dysenteriae in riverbed sediments of the Apies River. Experiments were performed in flow chambers containing three sediment types and connected to aquarium pumps immersed in river water to maintain continuous water circulation. Each chamber was inoculated with ~10 CFU/mL (final concentration) of each microorganism and kept at 4, 20 and 30 °C. Chambers were sampled on days 0, 1, 2, 7, 14 and 28. At 4 °C, only E. coli and S. typhimurium survived throughout the 28 experimental days. V. cholerae had the shortest survival time at this temperature and was not detected in any of the sediment chambers 24 h after inoculation. S. dysenteriae only survived until day 7. At an increased temperature of 20 °C, only S. dysenteriae was not detected on day 28 of the experiment. At 30 °C, V. cholerae and Salmonella survived longer (28 days) than E. coli (14 days) and S. dysenteriae (4 days). Vibrio cholerae was shown to have the highest T values (32 days) in all sediment types at 20 and 30 °C. We conclude that the sediments of the Apies River present a favourable environment for the survival of indicator and pathogenic bacteria depending on the prevailing temperature.

Microbial Remobilisation on Riverbed Sediment Disturbance in Experimental Flumes and a Human-Impacted River: Implication for Water Resource Management and Public Health in Developing Sub-Saharan African Countries

“…Schematic representation of sediment chambers used for the laboratory resuspension experiments (Figure modified from Abia et al [38]).…”

“…and Vibrio cholerae have also been detected in riverbed sediments in South Africa, indicating the possible presence of these pathogenic organisms [37]. In a study conducted by Abia et al [38], the authors demonstrated through laboratory experiments that these pathogens could survive in the sediments of the Apies River for up to 30 days. Despite this finding, current monitoring of the country’s water resources (as with many developing countries) for microbial quality does not take into consideration sediment quality [39].…”

Spatial Modelling of Bacterial Diversity over the Selected Regions in Bangladesh by Next-Generation Sequencing: Role of Water Temperature

“…However, they vary spatially, depending on different aspects like environmental factors, community adaptation and human activities [2][3][4]. The dynamics of bacterial communities in developing countries are poorly understood [5,6] including the present study area: selected regions of the Bay of Bengal, Bangladesh.…”

Impact of Climate Forecasts on the Microbial Quality of a Drinking Water Source in Norway Using Hydrodynamic Modeling

“…Apart from rainfall, water temperature variations have been shown to affect the growth and survival dynamics of microbial organisms in raw water sources [26][27][28][29]. Variations in water temperature, which is controlled by factors such as air temperature, cloud cover, solar radiation and other geomorphometric factors [30,31], affect the hydrodynamic distribution of microorganisms through increased stratification [30][31][32][33].…”