Thesis (M. Tech. (Biomedical Technology)) -- Central University of technology, Free State, 2013 / The objective of this study was to determine the prevalence of Listeria monocytogenes and also to assess the general hygiene of fresh milk in the Maseru area, Lesotho. A total of 200 milk samples (40 pasteurised and 160 raw milk samples) were used for the research. Raw milk samples were collected from the local farmers at the Dairy reception as they bring it for selling. Pasteurised milk samples were bought from different milk selling points in the Maseru area. The total aerobic plate count, total coliform count and total E. coli count for 160 raw milk samples and 40 pasteurised samples were performed to determine the quality of milk. Milk was enriched in selective broths to increase detection sensitivity and was directly plated on selective agars for direct bacterial enumeration. About 54.4% of the of the raw milk samples had total aerobic plate counts greater that 200 000 cfu/ml while 55.6% (89/160) of the raw samples had high counts of greater than 20 cfu/ml for total coliforms, and 21.9% (35/160) of the samples had higher than expected total E. coli counts. High total coliform count was detected in 17.5% (7/40) of the pasteurised milk samples and about 67.5% (27/40) of these samples exceeded the limit for total aerobic plate counts. The counts exceeded the milk standards for pasteurised milk. Phosphatase activity was detected in seven pasteurised milk samples, whereas 33 tested negative for phosphatase activity. Some pasteurised milk samples tested positive for coliform counts which exceeded the maximum limits according to national standards for pasteurised milk. However, most of the pasteurised samples (82.5%) had acceptable counts of less than 20 cfu/ml. API and PCR were used for confirmation and amplification of the isolated Listeria strains. The prevalence of Listeria was found to be (3.75%). Listeria species were found in 6 out of 200 samples tested (160 raw milk samples and 40 pasteurised milk), and were only detected in the raw milk samples. Five species belonged to Listeria monocytogenes and one was Listeria innocua. None of the Listeria was detected in the pasteurised milk samples. Serotyping was done through multiplex PCR with D1, D2, FlaA and GLT primers to determine the serovar groups of L. monocytogenes. All six isolates revealed 214 bp gene which identifies the serotypes in Lineages I or III. The genetic fingerprinting of the isolated Listeria was also determined. Enterobacterial Repetitive Intergenic Consensus (ERIC) sequence-based PCR was used to generate DNA fingerprints with ERIC specific primers. On the basis of ERIC-PCR fingerprints, three different DNA patterns could be discriminated among the analysed isolates. Three L. monocytogenes isolates showed similar DNA banding patterns, while two isolates both had different profiles. A questionnaire was used to determine consumption of raw (unpasteurised) milk or pasteurised milk and its products and it was completed by 300 households from the community. Although there was no indicated prevalence of raw (unpasteurised) milk consumption from the community, participants indicated symptoms alleged to consumption of pasteurised milk and/or milk products. According to community perception some of the dairy products consumed were allegedly implicated in food poisoning illnesses experienced. Participants indicated more symptoms with both fresh and sour milk consumption than in cheese and yogurt consumption.

Thesis (M. Tech. (Biomedical Technology)) -- Central University of technology, Free State, 2013 / Electromagnetic fields are present wherever electricity is created. The frequency range of these electromagnetic fields is from extremely low to extremely high. The fields present in domestic areas fall within the extremely low frequency range. These fields are created by domestic electrical appliances and telecommunication. There has been much debate on the effect of exposure to these fields on human health. Research has not yet been able to prove adverse effect of these fields on human health. In fact, the benefits of magneto therapy has been recognized and used for several decades. Recently a specific electromagnetic signal has been under investigation for its ability to stimulate the immune response. This signal is produced by a patented generator, called Immunent Activator. Studies performed with the Immunent Activator signal on farm animals revealed increased feed conversion and decreased intestinal lesions of animals with intestinal infections. Most of the research was performed on fish and fowls and evidence of similar findings in mammals is lacking. In the current study, mice were exposed to the Immunent BV signal for seven days, after which immune cell counts were performed and compared to the immune cell counts of a control group of mice which received no electromagnetic exposure. It was found that the T-lymphocyte population of immune cells in the exposed group of mice was statistically significantly higher than that of the control group. The neutrophil count was statistically significantly lower in the exposed group compared to the control group. These findings revealed evidence of immune stimulation in the mice which were exposed to the Immunent Activator signal. Suggestions for further research could be made with regard to specific mechanisms of immune stimulation. The findings of this and other related studies hold benefits for the farming and health industry.

Thesis (M. Tech. (Agriculture)) -- Central University of Technology, Free State, 2013 / ntroduction: Good quality Eucalyptus is of importance to South Africa’s pulp and paper industry. Limited land is available for forestry, therefore Eucalyptus with genotypes for good pulp and paper qualities, particularly hybrids, are bred and cloned via cuttings. Although these Eucalyptus clones keep the favourable genotypes in the population, many have difficulty with rooting. Research has shown that rhizobacteria can improve rooting. Thus, one strategy to enhance the rooting of cuttings is to use rhizobacterial preparations. The aim of this study was to characterise rhizobacterial communities of Eucalyptus hybrid and species and identify possible plant-growth promoting rhizobacteria (PGPR). Materials and methods: Rhizospheric samples were collected from Eucalyptus hybrids and species. The rhizobacterial communities were characterised using fatty acid methyl esters (FAME) analysis and denaturing gradient gel electrophoresis (DGGE). DGGE fragments were further sequenced to identify rhizobacteria. Results and discussion: FAME analysis successfully achieved a broad characterisation of the Eucalyptus hybrid and species rhizobacterial communities based on their fatty acid composition. Myristic acid (C14:0) was the most abundant fatty acid. DGGE profiles gave a molecular profile of the Eucalyptus hybrid and species rhizobacterial communities based on their DNA composition. Nitrosomona eutropha was present in all samples which illustrates a nitrogen-rich environment. Adhaenbacter aquaticus was unique to the better rooting Eucalyptus hybrid GU111. Conclusion: This study provided some insight into the diversity of rhizobacterial communities of Eucalyptus hybrids and species. Possible PGPR were identified and the observation made that the nature of the soil environment changes with the aging of the associated host. These findings allow further investigation into the formulation of potential rhizobacterial preparations for rooting enhancement of Eucalyptus cuttings.

Thesis (M. Tech. (Environmental Health)) - Central University of Technology, Free State, 2014 / In the battle to sustain and produce quality food that is safe and affordable, the limited legislative and regulatory environment continues to allow opportunities for food to become contaminated during processing. The degree of contamination distributed over the final food product (including meat products) depends upon several factors that include knowledge and behaviour of the food handlers, equipment, the hygiene habits of personnel, and the monitoring that takes place at food processing plants (including butcheries). The current study was conducted in five selected butcheries (forming 15% of the registered butcheries at the time the study was conducted) in the Mangaung Metropolitan municipal area, purposely targeting the ones registered with the municipality. The hygiene practices of meat handlers were assessed (through self-administered questionnaires) because meat is a perishable product that requires labour intensive processing for production of quality products. Thus, mishandling by food handlers may create and maintain conditions favourable to microbial contamination. Furthermore, the study assessed and characterised microbial contamination on working surfaces and utensils through swabs as well as bioluminescence instrument [Adenosine Tri-phosphate (ATP) Hygiena] for cleanness of the working environment. Concomitant to the above, meat handlers’ hands and aprons were also assessed for possible microbial contamination as well as their characterisation. Lastly, aerosolised microbes [through an air sampler (Surface Air System) SAS Super 90] were also collected for iv quantification and identification during working hours as airborne microbes can settle on working surfaces and/or utensils as a result of movement of workers and other related working processes. Statistical points such as correlations, standard deviations, group standard deviations as well as significant differences were captured per respective chapter where necessary. Data reported in this study is over 3 month period with two weeks intervals during sampling and thus reported as either weekly or rounds between sampling periods. The results of the current study indicate that the food safety objectives are negligibly achieved, indicating a need for proper food safety training which is audit based. On administration of a questionnaire, food handlers showed poor knowledge of food safety awareness coupled with poor attitude and behaviour in terms of food safety. The five butchery premises were further examined regarding the airborne and surface microbial loads, as well as that of the food handlers’ hands, during processing. The microbial loads in the air appeared to comply with the suggested limits at all the sampled butcheries. Microbial loads on meat contact surfaces showed levels conforming to the South African standard or guideline of 1 × 102 cfu.m-2. Total Coliforms on hands and on aprons were compared to the general microbial target value of <2.5 cfu.m-2 as suggested by literature. In this study, Matrix Laser Desorption Time of Flight Mass Spectrophotometer (MALDI-TOF MS) was found to be an accurate, rapid and cost effective method towards v identifying of foodborne pathogens and spoilage bacteria including yeast. Moreover, in recent years South Africa’s meat scandals have increased consumer awareness and the demand for food safety. Section 11 of the Meat Safety Act (Act no. 40 of 2000) stipulates that every abattoir must utilize an independent inspection service appointed by the department of agriculture to ensure that meat of high quality and wholesomeness is produced. However, once the meat and meat products leave the abattoir, they are under the jurisdiction of the local authorities who rely only on visual assessment as opposed to microbiological inspection in the maintenance of their hygiene and quality. Despite the high incidence of foodborne illnesses in both developed and developing countries; South African data on foodborne illness incidents is still insufficient. This could be attributed to the fact that in South Africa, legislation governing the acceptable standards of the levels of microbiota in the air and on food handlers’ hands is still inadequate. Additionally, lack of obligatory usage of Hazard Analysis Critical Control Point (HACCP) procedures in the meat premises poses a risk for economic productivity. In conclusion, the identification of airborne bacteria in the butcheries strongly suggests that in the planning of the existing establishments, the building layout, control of the traffic flow of personnel, the durability and imperviousness of floors, the ventilation system and the placement of the equipment were not carefully considered. This may play a role in the prevalence and proliferation of airborne microbes as the resulting establishments provide an environment conducive to the breeding of microbes. vi In regard to swabs, it was concluded that floors may present a high point of contamination possibly through aerosolization of microbial communities. Moreover, cleaning materials and hygiene practices need to be reviewed. The results of the administered questionnaire showed that food handlers should be sufficiently trained with regard to food quality management tools such as Good Manufacturing Practices (GMP), Hazard Analysis and Critical Control Point (HACCP) systems and food safety. The evaluation of meat contact surfaces for organic soils to determine their cleanliness using the rapid ATP bioluminescence testing can be convenient for everyone involved in the food chain since visual and touch inspection cannot be conclusive enough to meet regulatory requirements in terms of microbial counts.

Thesis (M. Tech.) - Central University of Technology, Free State, 2010 / The objective of this research study was to quantify the differences in average daily gain (ADG), back fat thickness (BFT), eye muscle area (EMA), fat thickness (FT) on different body parts, the feed conversion ratio (FCR) and body dimensions (by means of body measurements) of Dorper lambs exposed to supplemented light. For this study 120 Dorper lambs (115 ± 10 days old) weighing (29.76 ± 5.01kg) were used. The lambs were randomly divided into three homogeneous groups (20 castrated and 20 intact males). The three groups were then exposed to different levels of supplemented light at 145 lux (16h, 24h and normal photoperiod). The animals were fed ad libitum with pellets containing 9.5 MJ ME/kg DM and 12% CP in open pens. The animals were weighed every 7 days while ultrasound scanning of the EMA and the BFT was done at the beginning and the end of the 35 day trial. The ADG, FCR and feed intake (FI) were calculated at the end of the trial. Linear body measurements including shoulder height, body length and heart girth were taken at day 1 and day 35 respectively. All the animals were slaughtered at the end of the trail. The carcasses were then weighed, graded and the FT was measured with a caliper. The final results of the study showed that no significant differences between the three treatment groups (consisting of wethers and rams) in terms of body measurements, ultrasound scanning ADG and FCR could be detected. However, a significant difference was found between the wethers and the rams in the whole trial for ADG. The ADG of the rams exposed to 16 hours of supplemented light was significantly better than the normal photoperiod and the 24 hour light supplementation group.

Thesis (M. Tech.) - Central University of Technology, Free State, 2009

Thesis (M. Tech.) - Central University of Technology, Free State, 2010

Thesis (M. Tech.) -- Central University of Technology, Free State, 2009 / Contradictory results are reported regarding the value of external representations such as dynamic and static visuals in a learning environment (Lowe 1999; Hanzen, Narayanan & Hegarty 2002; Weiss, Knowlton and Morrison 2002; Bodemar, Ploetzner, Feuerlein & Spada 2004; Bodemar & Ploetzner 2004; Moreno & Valdez 2005; Höffler & Loetner 2007). Some of the recent findings indicate little or no significant differences between static and dynamic visuals. This study looks at studies that used a variety of external representations to facilitate different learning tasks. A ―two journal article‖ format was adopted for Chapter 2 and 3 respectively. The first article, i.e. Chapter 2, is a review of the literature and provides a theoretical background to the research topic. Chapter 2 reviews theories and empirical studies regarding learning with text, dynamic and static visuals, and examines the conditions under which external representations facilitate learning. Subjects‘ prior knowledge, the content of the instructional material and the testing method are but some of the variables that can determine if graphic medium can increase a subject‘s comprehension and if such comprehension can be accurately measured. Chapter 2 also presents a model that suggests how dynamic and static visuals can be used in a learning environment. The second article, i.e. Chapter 3, presents an animation for a specific learning task in order to test the hypothesis that this external representation may improve the comprehension of a linear scientific process. Tertiary students (N = 61) participated in a pre-test and post-test experimental study during which they were exposed to 4 treatment variables: text (T), video and text (VT), illustration and text (IT), and animation and text (AT). It was hypothesised that the group who received the animation and text treatment would comprehend the linear process better than the control group (text only) and the other two groups (text and illustration; text and video). The question that was asked to explore this comparison therefore was: Can animation be used to improve comprehension of instructional text? The results indicate that no significant differences in achievement existed among the treatment groups. The results of the study show that dynamic visuals with text can have essentially the same effect on students' understanding of a particular process as static visual with text. It is further acknowledged that the subjects‘ prior knowledge, the content of the instructional material and the testing method are but some of the variables that can determine if an external representation can increase a subject‘s comprehension and if such comprehension can be accurately measured.

Thesis (D. Tech.) - Central University of Technology, Free State, 2009

Thesis (M. Ed.) - Central University of Technology, Free State, 2007