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25 May 2020 | Story Prof Danie Brand | Photo iStock

We are indeed privileged to have this paper from Prof Toyin Falola to include in our celebrations of Africa Day. Toyin Falola is a world-renowned African. A scholar of African history and African studies, he holds the Jacob and Frances Sanger Mossiker Chair in the Humanities at the University of Texas, Austin. He has published, as author or editor, more than 100 scholarly books on topics ranging from diaspora, migration, empire and globalization to intellectual history, international relations, religion and culture. He has been awarded seven honorary doctorates and has received, among many other awards, the Distinguished Africanist Award from the African Studies Association, the Ibadan Foundation Award for Professional Excellence in Scholarship and the Cheikh Anta Diop Award for Excellence in African Studies. He served as Vice President of UNESCO’s International Scientific Committee, Slave Route Project from 2011 – 2015 and currently is a member of the Carnegie African Diaspora Fellows Programme and the International Committee of the Thabo Mbeki African Leadership Institute at UNISA.

In this wide-ranging paper, originally presented as keynote address at the Visions of African Unity (1930s – 2018) conference at the University of the Free State, Prof Falola begins with a tour of the intellectual history of ideas of African Continentalism (Pan-Africanism / African Unity), from Henry Sylvester Williams, through WEB du Bois, Marcus Garvey, George Padmore and Julius Nyerere, to Kwame Nkrumah. He then describes the current institutional landscape of African unity and present-day intellectual versions of African Continentalism. Asking, and answering the question ‘Why must Africa unite?’, he then proceeds, on the basis of a consideration of more contemporary intellectual versions of African continentalism such as Black Consciousness, Black Nationalism, Afropolitanism, and now Afrofuturism (which he depicts as ‘ideological dispensations of true African cultural recovery and re-orientation’), to propose a disaggregated approach to contemporary African unity that is not fixated on global-Northern models. This means that unity should (re)start small, working territorially from regional units toward a continental unit, on the one hand; and on the other, seeking unity and cooperation around discrete substantive themes, from the more obvious and traditional, such as economic policy, global politics and a reformed unified political and military system, to the less, such as common educational policy, synergizing science and technology with African culture(s) and language, culture and literary exchange.

We thank him for the gift.

News Archive

Research eradicates bacteria from avocado facility
2017-01-17

 Description: Listeria monocytogenes Tags: Listeria monocytogenes

Listeria monocytogenes as seen under an electron
microscope. The photo was taken with a transmission
electron microscope at the microscopy unit of the UFS.
Bacteriophages (lollipop-like structures) can be seen
next to the bacterial cells.
Photo: Supplied

“The aim of my project was to identify and characterise the contamination problem in an avocado-processing facility and then to find a solution,” said Dr Amy Strydom, postdoctoral fellow in the Department of Microbial Biochemical and Food Biotechnology at the University of the Free State (UFS).

Her PhD, “Control of Listeria monocytogenes in an Avocado-processing Facility”, aimed to identify and characterise the contamination problem in a facility where avocados were processed into guacamole. Dr Strydom completed her MSc in food science in 2009 at Stellenbosch University and this was the catalyst for her starting her PhD in microbiology in 2012 at the UFS. The research was conducted over a period of four years and she graduated in 2016. The research project was funded by the National Research Foundation.

The opportunity to work closely with the food industry further motivated Dr Strydom to conduct her research. The research has made a significant contribution to a food producer (avocado facility) that will sell products that are not contaminated with any pathogens. The public will then buy food that is safe for human consumption.


What is Listeria monocytogenes?

Listeria monocytogenes is a food-borne pathogenic bacterium. When a food product is contaminated with L. monocytogenes, it will not be altered in ways that are obvious to the consumer, such as taste and smell. When ingested, however, it can cause a wide range of illnesses in people with impaired immune systems. “Risk groups include newborn babies, the elderly, and people suffering from diseases that weaken their immune systems,” Dr Strydom said. The processing adjustments based on her findings resulted in decreased numbers of Listeria in the facility.

The bacteria can also survive and grow at refrigeration temperatures, making them dangerous food pathogens, organisms which can cause illnesses [in humans]. Dr Strydom worked closely with the facility and developed an in-house monitoring system by means of which the facility could test their products and the processing environment. She also evaluated bacteriophages as a biological control agent in the processing facility. Bacteriophages are viruses that can only infect specific strains of bacteria. Despite bacteriophage products specifically intended for the use of controlling L. monocytogenes being commercially available in the food industry, Dr Strydom found that only 26% of the L. monocytogenes population in the facility was destroyed by the ListexP100TM product. “I concluded that the genetic diversity of the bacteria in the facility was too high and that the bacteriophages could not be used as a control measure. However, there is much we do not understand about bacteriophages, and with a few adjustments, we might be able to use them in the food industry.”

Microbiological and molecular characterisation of L. monocytogenes

The bacteria were isolated and purified using basic microbiological culturing. Characterisation was done based on specific genes present in the bacterial genome. “I amplified these genes with polymerase chain reaction (PCR), using various primers targeting these specific genes,” Dr Strydom said. Some amplification results were analysed with a subsequent restriction digestion where the genes were cut in specific areas with enzymes to create fragments. The lengths of these fragments can be used to differentiate between strains. “I also compared the whole genomes of some of the bacterial strains.” The bacteriophages were then isolated from waste water samples at the facility using the isolated bacterial strains. “However, I was not able to isolate a bacteriophage that could infect the bacteria in the facility.

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