Academic Support
Permanent URI for this communityhttp://ir-dev.dut.ac.za/handle/10321/210
Browse
3 results
Search Results
Item Exploring the potential reservoirs of non specific TEM beta lactamase (blaTEM) gene in the Indo-Gangetic region : a risk assessment approach to predict health hazards(Elsevier, 2016) Singh, Gulshan; Vajpayee, Poornima; Rani, Neetika; Amoah, Isaac Dennis; Stenström, Thor-Axel; Shanker, RishiThe emergence of antimicrobial resistant bacteria is an important public health and environ-mental contamination issue. Antimicrobials of -lactam group accounts for approximately two thirds, by weight, of all antimicrobials administered to humans due to high clinical efficacy and low toxicity. This study explores -lactam resistance determinant gene (blaTEM) as emerging con-taminant in Indo-Gangetic region using qPCR in molecular beacon format. Quantitative Microbial Risk Assessment (QMRA) approach was adopted to predict risk to human health associated with consumption/exposure of surface water, potable water and street foods contaminated with bac-teria having blaTEM gene. It was observed that surface water and sediments of the river Ganga and Gomti showed high numbers of blaTEM gene copies and varied significantly (p < 0.05) among the sampling locations. The potable water collected from drinking water facility and clinical set-tings exhibit significant number of blaTEM gene copies (13 ± 0.44–10200 ± 316 gene copies/100 mL).Item Quantification of pathogen inactivation efficacy by free chlorine disinfection of drinking water for QMRA(IWA Publishing, 2015-09-13) Petterson, S.R.; Stenström, Thor-AxelTo support the implementation of quantitative microbial risk assessment (QMRA) for managing infectious risks associated with drinking water systems, a simple modeling approach for quantifying Log10 reduction across a free chlorine disinfection contactor was developed. The study was undertaken in three stages: firstly, review of the laboratory studies published in the literature; secondly, development of a conceptual approach to apply the laboratory studies to full-scale conditions; and finally implementation of the calculations for a hypothetical case study system. The developed model explicitly accounted for variability in residence time and pathogen specific chlorine sensitivity. Survival functions were constructed for a range of pathogens relying on the upper bound of the reported data transformed to a common metric. The application of the model within a hypothetical case study demonstrated the importance of accounting for variable residence time in QMRA. While the overall Log10 reduction may appear high, small parcels of water with short residence time can compromise the overall performance of the barrier. While theoretically simple, the approach presented is of great value for undertaking an initial assessment of a full-scale disinfection contactor based on limited site-specific information.Item Schools as potential risk sites for Vector-Borne disease transmission: mosquito vectors in rural schools in two municipalities in Colombia(The American Mosquito Control Association, Inc., 2015) Olano, Victor Alberto; Matiz, María Inés; Lenhart, Audrey; Cabezas, Laura; Vargas, Sandra Lucía; Jaramillo, Juan Felipe; Sarmiento, Diana; Alexander, Neil; Stenström, Thor-Axel; Overgaard, Hans J.Dengue and other vector-borne diseases are of great public health importance in Colombia. Vector surveillance and control activities are often focused at the household level. Little is known about the importance of nonhousehold sites, including schools, in maintaining vector-borne disease transmission. The objectives of this paper were to determine the mosquito species composition in rural schools in 2 municipalities in Colombia and to assess the potential risk of vector-borne disease transmission in school settings. Entomological surveys were carried out in rural schools during the dry and rainy seasons of 2011. A total of 12 mosquito species were found: Aedes aegypti, Anopheles pseudopunctipennis, Culex coronator, Cx. quinquefasciatus, and Limatus durhamii in both immature and adult forms; Ae. fluviatilis, Cx. nigripalpus, Cx. corniger, and Psorophora ferox in immature forms only; and Ae. angustivittatus, Haemagogus equinus, and Trichoprosopon lampropus in adult forms only. The most common mosquito species was Cx. quinquefasciatus. Classrooms contained the greatest abundance of adult female Ae. aegypti and Cx. quinquefasciatus. The most common Ae. aegypti breeding sites were containers classified as “others” (e.g., cans), followed by containers used for water storage. A high level of Ae. aegypti infestation was found during the wet season. Our results suggest that rural schools are potentially important foci for the transmission of dengue and other mosquito-borne diseases. We propose that public health programs should be implemented in rural schools to prevent vector-borne diseases.