m olecular Pathogenic m icrobiology r esearch g roup

Prof Sehaam Khan

The main focus area of this research group is waterborne pathogens, specifically bacteria and viruses in wastewater, river water and roof-harvested rain water. Projects are carried out in collaboration with the Water Research Group within the Department of Microbiology, Stellenbosch University.

Highlights for 2014

Project 1

Numerous research groups have demonstrated that many wastewater treatment (WWT) processes are ineffective in their ability to remove antibiotic compounds from the wastewater effluent. This implies that antibiotics and antimicrobial resistant strains may be present and persist in treated wastewater effluent that is usually released into a neighbouring surface water source.

- PhD study – (1) Comparison of remediation techniques (incorporating absorbing filtration, such as activated carbon; constructed floating bed systems which evaluate grass varieties such as ryegrass and vetiver grass; and solar pasteurisation, etc.) to decrease the level of antibiotics and antibiotic resistant strains in irrigation water; (2) Identification of novel biosurfactants from microorganisms isolated from wastewater

- MTech study – The level and persistence of antibiotic resistant strains of bacteria in wastewater before, during and after treatment at a municipal WWT plant in Stellenbosch

Project 2

Access to clean water is essential for maintaining human health, as water-related diseases lead to millions of deaths and many cases of illness annually. Rainwater harvesting has thus been earmarked as an additional water source which could provide clean and potable water directly to the consumer.

- PhD study – Research on Legionella pneumophila (L. pneumophila) has increased in recent years; it is evident that this pathogen has evolved sophisticated mechanisms that enable it to adapt to environmental conditions through its ability to enter, survive and replicate in protozoan species. However, the precise understanding of how L. pneumophila survives in adverse environmental conditions and manipulates host cell functions on the mechanistic level is still largely unknown. The aim of the proposed research is thus to implement an innovative in vitro system to study interactions between L. pneumophila and amoebae (indigenous to harvested rainwater). Another goal of this research is to investigate the survival and proliferation of Legionella species in point-of-use treated harvested rainwater.

- MSc (Micro) study – A study was done on the application of viability assays to monitor the efficiency of solar pasteurisation for the treatment of rainwater.

- MSc (Micro) study – Research was done on microbial and chemical source tracking markers for the detection of human contamination in rainwater.

Further Projects

- Characterisation of an indigenous Trichoplusia ni baculovirus (TniSNPV), for use as a biological pest control agent

- Molecular biology techniques to screen for the development of multidrug resistance in Klebsiella pneumoniae found to cause nosocomial infections

- Colonisation rate of and characterisation of the antibiotic resistance and sero-type profile of group B Streptococcus (GBS) among pregnant Namibian women

- Molecular characterisation of Mycobacterium tuberculosis clinical isolates obtained in the Khomas region, Windhoek