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The effect of supplementation of plant and animal-derived dietary oils in pre- and post-parturition Döhne merino ewes on the growth performance of the lambs
(Central University of technology, 2024-06) Sedupane, Tebogo
The objective of this study was to investigate the effect of dietary supplementation of sunflower oil, olive oil, fish oil, and palm oil to pre- and post-parturition Döhne Merino ewes on lamb growth performance. Birth weight, post-natal growth rate, and weaning weight of lambs suckling on supplemented ewes were compared. Fifty South African Döhne Merino ewes, 2–4 years old (second parity), weighing 46–55 kg, with a mean body condition score (BCS) of 3.5 ± 0.4, were randomly divided into groups of 10 animals each. Each group (n = 10 per group) received a daily dose of 30 ml of either sunflower, olive, fish, or palm oil, while the control group received no oil. The study was conducted over a period of 210 days (i.e., 7 months). Oestrus was synchronised through the use of controlled internal drug release (CIDR) devices inserted intravaginally for a period of 15 days. Oestrus synchronisation and oil supplementation commenced simultaneously. At CIDR withdrawal, ewes were injected intramuscularly with 200 IU Pregnant Mare Serum Gonadotrophin (PMSG). Fixed-time laparoscopic artificial insemination (LAI) was performed with diluted Döhne Merino semen 48 hours following CIDR removal. Two weeks after LAI, follow-up Döhne Merino rams were introduced to all 50 ewes for 2 weeks to mate ewes that exhibited any signs of oestrus, as this is standard procedure of the experimental farm, and it was also importatnt that all selected ewes for the experiment conceive, although not part of the objectives of the present research. The production parameters were expressed as an average per group. The mean conception rate and lambing rate of ewes across all groups were 88%. The olive oil treatment recorded the highest conception rate and lambing rate (100% for both), but did not differ significantly (P> 0.05) from other groups. followed by sunflower oil (90%), fish oil (90%), palm oil (70%); the control group had rates of 90%. post-hoc test using Tukey’s HSD to identify significant differences between treatment groups at specific time points at a 95% confidence interval. The IBM Statistical Package for the Social Sciences (SPSS) 27 software programme was utilised. The shortest gestation length of 150 days was recorded for the control group. The gestation lengths of the sunflower oil, olive oil, fish oil, and palm oil groups were 153, 156, 155, and 156 days, respectively, with no significant differences (P > 0.05) between any groups. The birth weights of female lambs from the control, sunflower oil, olive oil, fish oil, and palm oil groups were 5.41 ± 0.87 kg, 5.70 ± 0.61 kg, 5.8 ± 0.70 kg, 5.8 ± 0.74 kg, and 4.9 ± 0.50 kg, respectively. The birth weights of male lambs from the control, sunflower oil, olive oil, fish oil, and palm oil groups were 5.6 ± 1.19 kg, 4.85 ± 0.70 kg, 5.6 ± 0.84 kg, 5.5 ± 0.49 kg, and 5.4 ± 0.33 kg, respectively. The results indicate no significant difference (P > 0.05) between different treatment groups for birth weights for both male and female lambs. There was improvement or significance (P>0.05) on percentage increment in weight over time in weeks 5,9 and 11. There was significant difference experienced in ADG of lambs among groups in weeks 5,6,10,11 and 13. There was no significant difference (P > 0.05) observed in the final body weight at weaning for both males from the control, sunflower oil, olive oil, fish oil, and palm oil groups (28.8 ± 4.93 kg, 25.5 ± 8.13 kg, 29.0 ± 4.88 kg, 30.2 ± 4.59 kg, and 28.8 ± 5.03, respectively) and females from the control, sunflower oil, olive oil, fish oil, and palm oil groups (28.5 ± 4.58 kg, 28.3 ± 3.81 kg, 25.8 ± 6.93 kg, 28.9 ± 4.51 kg, and 27.6 ± 2.46 kg, respectively) for the lambs of ewes supplemented with different experimental dietary oils. There was difference in the effect of plant and animal-derived dietary oils – namely sunflower oil, olive oil, fish oil, and palm oil – on the percentage increment in weight over time and ADG of lambs among groups. The growth performance of the lambs was similar to the control group. It can thus be concluded that, in this study, diets enriched with plant and animal-derived dietary oils pre- and post-mating had an effect on growth performance in Döhne Merino sheep.
Enumeration of phyllo-epiphytic and endophytic pathogens on leafy greens from farms and retails as affected by production parameters in the Free State, South Africa.
(Central University of technology, 2025-06) Mohapi, Dineo Attela
Leafy vegetables are a highly variable group of perishable foods that broadly can be defined as vegetables grown for their edible leaves. This study was conducted to investigate the production parameters at the farms and how they influences the end product. The study characterises opportunistic pathogens from various farms and retails and identify the aetiology and how these organisms affect human health and also emphasise the significance of sources that are regarded as microbial hazards or act as resevoirs for pathogenic organisms. Considering one health perspective it is also imperative to pay more attention to the presence of zoonotic pathogens that are resistance to certain antbiotics as it is a public health threat and a challenge that need to be highlighted due to high level of infectious illness caused by zoonotic and opportunistic pathogens. Since various agronomic activities leads to contamination of leafy greens in various stages of minimal processing including distribution, it is thus crucial to address such concerns at small-scale farms to mitigate cross-contaminate to the retails and provide an insight on hygiene and sanitation in both spheres. Minimal process includes many stages which introduces the disruption of tissue including cell integrity resulting in product harbouring of opportunistic pathogens. Spinach (Spinacia oleracea L.) and cabbage (Brassica oleracea var. capitata L.) are considered staple food in South Africa and are consumed daily, they were chosen due to their minimal processing in production, demand, purchase and their difference compared to intact vegetables regarding their physiology, processing, handling including storage. The study profiles and characterise opportunistic and zoonotic pathogens from both regimens due to processing parameters, hygiene practises and possible succession of pathogens form one niche to the other. The first survey was on the enumeration of microbiota on spinach and cabbage isolates from various farms including their storage crates. Secondly, the objective was to enumerate microbiota from spinach and cabbage from retails and further investigate the extent of these pathogens, the succession at the retail level, observe the proliferation of pathogens introduced along the way due to amplification. Fresh leafy spinach, crates and cabbage samples were analysed for each of the following microorganisms: total aerobic mesophilic bacteria, total coliforms, coagulase-positive Staphylococci, Listeria and Bacillus and further identification of isolates was done by utilisng Analytic Profile Index. Lastly, conduct antimicrobial susceptibility profile of identified opportunistics bacteria from farms and retails, the isolates were evaluated utilising Kirby-Bauer disk diffusion method against nine antibiotics from nine categories: penicillin (P; 10_μg), ampicillin (AMP; 10_μg), gentamicin (CN; 10_μg), ceftazidime (CAZ; 30_μg), chloramphenicol (C; 30_ μg), tetracycline (TE; 30_μg), vancomycin (VA; 30_μg), erythromycin (E; 15_ μg) and ciprofloxacin (CIP; 5_ μg). In this study, three farms had the highest number of opportunistic pathogens identified for cabbage with the least number of pathogens observed in the other two farms. With regards to spinach, two farms had the highest number of identified pathogens including Proteus mirabilis, Escherichia coli, Staphylococcus aureus, Serratia species and Listeria species and the lowest number was observed in the other two farms. Concerning spinach crates, two farms had the highest number of pathogens identified and the least numbers were observed in the other two farms. This indicate contamination mostly from livestock manure utilised on the crops including insufficient hygiene from workplace. Secondly, three retails had the highest number of pathogens identified for cabbage compared to the other two retails. With regard to spinach, three retails had the highest number of identified pathogens including Bacillus spp., Enterobacter cloacae, Listeria ivanovii and Listeria monocytogenes species compared to the other two retails. The study also highlights additional bacterial species enumerated from both commodities in two different environments. The additional species characterized are a result of proliferation introduced due to agronomic parameters, cold chain supply, and retail activities. The combined result of total coliforms and opportunistic pathogens found on the end-products indicates poor minimal processing, poor hygiene and sanitation standards. Lastly, Enterobacter cloacae, Staphylococcus aureus, Micrococcus luteus, Staphylococcus sciuri, Acinetobacter haemolyticus, Burkholderia cepacia, Psuedomona luteola, Escherichia coli, Citrobacter freundii and Serratia marcescens were tested again nine antibiotics. Multidrug resistance was observed with 79% resistance, this is a public health threat that points out challenegs regarding treatment of infections caused by these opportunistic and zoonotic pathogens. Rapid identification of antibiotics is essential and crucial for the development of effective antimicrobial compounds as well as prevention of antibiotic resistance. Necessary measures should be taken to reduce the level of contamination from small-scale farms to reduce antibiotic consumption in humans.
Inhibitory effects of South African plants against mycotoxigenic phytopathogens
(Central University of technology, 2024-09) Mariri, Ntagi Gerald
Mycotoxigenic fungal strains pose a significant threat to food crops consumed by humans and animals, leading to reduced yields and compromised food quality as reported in almost 25% of maize products worldwide. The harmful effects following the ingestion of mycotoxin-contaminated food include inducing cancers, mutagenicity, immune suppression, and toxicities to target organs of the digestive, cardiovascular, and central nervous systems. Synthetic fungicides are associated with a high potential for toxic residues in food and the development of fungal resistance. Genetically modified crops can also reduce crop contamination. However, these strategies are inaccessible and expensive resources for most subsistence farmers. To address these issues, the use of plants as potential biopesticides to counter fungal infections on crops emerges as a possible solution to enhance food safety and security. This study aimed to determine the antifungal activities of Bauhinia galpinii N. E. Br., Combretum caffrum (Eckl. & Zeyh.) Kuntze, Markhamia obtusifolia (Baker) Sprague, and Maytenus undata (Thumb.) Blakelock, against mycotoxigenic fungi and potentially develop plant-based bio-fungicides. The leaves of the ethnobotanically selected plants were extracted using methanol and tested for antifungal activity against phytopathogenic strains of Aspergillus parasiticus, Aspergillus nomius, Fusarium verticilloides, Fusarium graminearum, Fusarium oxysporum, Penicillium haloterans and Cladosporium cladospoides. The antioxidant activities of the extracts were tested using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azinobis (3-ethylbenzthiazoline-6-suphonic acid) (ABTS) assays. The MTT (3-(4,5-dimethylthiazol-2-yl)-2,5- diphenyltetrazolium bromide) cytotoxicity assay was used to investigate the effects of the extracts on the viability of the African green monkey kidney (Vero) cells and the human colorectal adenocarcinoma (Caco-2) cells. Additionally, the micronucleus test was used to examine the potential of these plants to induce genotoxicity in Vero cells. The identity and quantity of phytocompounds in the plant extracts were analysed using gas chromatography (GC-ToF-MS) mass spectrometry and liquid chromatography time-of-flight mass spectrometry (LC-TOF-MS) analysis. The highest percentage extract yield was recorded from Combretum caffrum (23%), while Markhamia obtusifolia yielded 10.7%. Bauhinia galpinii methanol extracts had the lowest MIC value of 0.16 mg/ml against Furasium graminearum, Furasium oxysporum, Penicillium haloterans, and Cladosporum cladospoides at 24-hour incubation period. C. caffrum had a MIC value of 0.31 mg/ml against F. vercitilloides and F. graminearum. C.caffrum had the highest total activity (TA) of 1437.5 ml/g against the fungal pathogen, Aspergillus nomius. In the antioxidant studies, C. caffrum had good antioxidant activity against DPPH with 50% inhibitory concentration (IC50) value of 10 μg/ml, while B. galpinii had IC50 value of 50 μg/ml against free radicals of ABTS. Based on the ABTS/DPPH correlations (ADC), M. undata exhibited a notable ADC correlation of 2.33, which is over three-fold that of the ADC of ascorbic acid (control drug). Furthermore, all extracts were assayed for cytotoxicity and genotoxicity using the MTT and micronucleus assays, respectively. In the cytotoxicity studies, B. galpinii, C. caffrum, and M. undata extracts were cytotoxic to Vero cells at 500 μg/ml. C. caffrum and M. undata extracts demonstrated cytotoxic effects on human colorectal adenocarcinoma cells in a dose-dependent manner. C. caffrum extract significantly reduced cell viability by up to 89.61% at the highest concentration of 500 μg/ml. M. undata extract was also cytotoxic at the highest tested concentration of 500 μg/ml. B. galpinii extracts increased the viability of the cancer cells, indicating a potential stimulation of cell proliferation. The extract from M. obtusifolia had no effect on the cells at the tested concentrations of 250 and 500 μg/ml. These findings suggest that C. caffrum and M. undata extracts have potential as cytotoxic agents against colorectal adenocarcinoma cells, while B. galpinii extracts may not be suitable for cancer treatment. All tested plant extracts were genotoxic at the highest tested concentration of 500 μg/ml. C. caffrum showed genotoxicity at 250 μg/ml and reduced cell numbers to less than 50% of the control at 500 μg/ml, indicating its significant cytotoxic potential. Three of the four medicinal plants reported a higher phenolic content (TPC) compared to their total flavonoid compounds. These higher TPC contents may well explain the antimycotoxigenic and antioxidative ability of the medicinal plants selected for the current study. The GC-ToFMS analysis of the selected medicinal plants revealed that all the extracts contained Hexadecanoic acid (HA) and methyl ester. B. galpinii and C. caffrum exhibited the presence of lupeol, while M. obtusifolia and M. undata contained phytol. Kaempferitrin was identified following the LC-TOF-MS analysis of both B. galpinii and M. obtusifolia. Quercitrin was identified from C. caffrum, while rutin and pisumionoside were identified from M. undata. Overall, the study concluded that the strong inhibitory effects against various fungal pathogens shown by some of the tested plants indicate that investigating plants as potential solutions for fungal infections in crops offers a promising avenue to enhance food safety and security in developing and underdeveloped countries. Therefore, it is important to intensify efforts to explore the use of plants as potential biopesticides. To further advance the findings of the current study, continued research and safety assessments of the tested South African plant extracts are essential to fully exploit their potential benefits in agriculture and healthcare while mitigating any risks to human health and the environment.
Microbial profiling of food contact surfaces in hospitals at Maseru Lesotho
(Central University of technology, 2025-07) Maliehe, Salmina Mankomane
Food handlers play a key role in ensuring food safety throughout the food production, processing, storage, and preparation chain. In food service establishments, the common sources of microbial contamination reportedly originate from dirty food contact surfaces, poor personal hygiene practices, and inappropriate storage temperatures. Contamination primarily arises from food contact surfaces such as utensils, equipment, and food handler hands or clothing. The overall purpose of this study was to investigate microbial contamination of food contact surfaces in hospital kitchens in the city of Maseru, Lesotho. The objectives were to assess food handlers’ knowledge, attitudes, and hygiene practices and to characterize prevalent hospital foodborne pathogens associated with food contact surfaces. The study also evaluated the efficacy of common disinfectants against microorganisms and investigated the production of extended-spectrum beta-lactamase (ESBL) against Gram-negative bacteria. The study was conducted in five hospitals involving food handlers ranging between 2-7 per hospital. A total of 26 food handlers participated in the study. A structured questionnaire that had been derived from previous studies was used to assess the food handlers’ knowledge, attitudes, and practices (KAPs). The microbial isolates were identified to specie level by use of biochemical test kits (Staph API, RAPID ONE and RAPID NF Plus). The identified Gram-negative bacteria were subjected to a series of antimicrobials in order to determine the susceptibility profile using the Kirby-Baur disc diffusion method. The phenotypic tests for ESBL detection were used to test for ESBL production with subsequent double disc synergy test used as a confirmation method. Isolates were further subjected to the Kirby-Baur disc diffusion method to establish susceptibility to common disinfectants. Subsequently, the minimum inhibitory concentrations and the minimum bactericidal concentrations were determined by using the in-vitro susceptibility test employing 96-well microtiter plates. More female (n=23; 88%) than male (n=3; 12%) food handlers participated in the study. The majority of these food handlers (n=25; 96%) were aware that proper cleaning and sanitization of utensils decreases the risk of contamination. Although 54% (n=14) of the food handlers reported that they had received training, none of the food handlers were could provide formal documentation to verify their training. However, there was general consensus (n=26; 100%) that food safety training is important. Despite the evident lack of knowledge regarding refrigeration and holding temperatures for hot ready-to-eat foods, the food handlers agreed that refrigerators/freezers should be checked regularly to reduce the risk of contamination. The microbial analysis study revealed that food contact surfaces, including food handlers’ hands, yielded high counts of all detected microorganisms (TVC, total coliforms, Escherichia coli, Staphylococcus sp., Salmonella sp., and Pseudomonas sp). This indicated a discrepancy between knowledge of food processing and of environmental and personal hygiene. In natural settings, microorganisms can be introduced in various ways by means of people, food, water bioaerosols, and domestic animals. The acquisition of microorganisms such as Stenetrophomonas maltophilia, Sphingomonas paucimobilis, and Myroides odorantum that are predominantly associated with clinical infections was evidence of possible cross-contamination from the hospital wards to the kitchen. The investigation of the extended-spectrum beta-lactamase (ESBL) production of Gram-negative bacteria revealed positive ESBL production in 43% of the microorganisms. This is an important finding given that the ESBL-producing genes can be transferred within niches and the production of these enzymes confers resistance to most commonly used antibiotics. Additionally, there was a 71% multidrug resistance among isolates and none of the microorganisms tested showed susceptibility to current antibiotics. However, a 100% resistance to penicillin was noted which affirms the growing resistance of microorganisms to common antibiotics and the need for new treatment options. The high resistance profile demonstrated by microorganisms in this study can be attributed to personal prescription of antibiotics as these antibiotics are available at pharmacies without a doctor’s prescription. The investigation of the efficacy of the disinfectants against the Gram-negative and Gram-positive bacteria revealed that both disinfectants 1 and 2 exhibited antimicrobial properties against the tested microorganisms. However, disinfectant 2 was found to have bactericidal effect against only the Gram-positive bacteria. The results therefore indicated that although there was an antimicrobial effect of disinfectant 2 against Gram-negative bacteria, disinfecting surfaces with such a disinfectant will not render the surface free from Gram-negative bacteria.
Water quality of the Bloemspruit stream on the outskirts of Bloemfontein, Free State, South Africa.
(Central University of technology, 2024) Letsoela, Mahlape Patricia
Introduction: The streams in the Free State play a crucial role in providing water for agricultural, industrial and recreational activities as well as in domestic households for sanitation purposes. These streams also provide a healthy home for numerous aquatic animals and plants. However, in recent years, there has been an upsurge in stream water pollution by anthropogenic activities. These include domestic, agricultural and industrial activities, such as waste water treatment plant (WWTP) that dispose of effluent containing high concentrations of emerging contaminants into the streams. The polluted water may cause illness in and deaths of humans and animals as well as kill less tolerant aquatic organisms resulting in a declined biological diversity of the stream. Therefore, water quality of the Bloemspruit and its tributaries, the Fonteinspruit and the Renosterspruit was assessed to determine the health and deterioration of the stream. Methodology: For water quality assessment, water samples were collected from 11 sampling sites in Bloemspruit stream and its tributaries during four sampling rounds. These water samples were assessed for four physical, seven chemical and two microbiological properties as well as eight emerging contaminants. The impact of pollution on the macroinvertebrate population and the macroinvertebrate habitat was conducted. The calculations of the Water Quality Index (WQI), the South African Scoring System score (SASS), the Average Score per Taxon (ASPT) and the Index of Habitat Integrity (IHI) score were used to determine the health of the Bloemspruit and its tributaries. Results and discussion: The results revealed that of the twenty-one properties of water measured, only five properties, i.e. temperature, pH, sulphate, total hardness and estradiol, were compliant in all the sampling rounds. The measurements of dissolved oxygen were relatively low. However, turbidity, nitrates, phosphates, E. coli, total coliforms, atrazine, metolachlor, terbuthylazine, carbamazepine, estrone, 17a-ethinylestradiol and bisphenol A all demonstrated relatively high measurements when compared with the proposed water quality limits for the protection of aquatic ecosystems. The WQI revealed that none of the sampling sites were of good quality. However, 45% demonstrated a fair condition, 45% were marginal and 10% poor. The SASS and ASPT scores revealed that 44% of the sampling sites were severely impaired with only a few tolerant macroinvertebrate taxa present, while the remaining 56% of the sampling sites were critically impaired. The IHI score demonstrated that 89% of the macroinvertebrates sampling sites had a moderately modified habitat, however, the remaining sampling site, S9, revealed a largely modified macroinvertebrate habitat. Conclusion: This study revealed that the water quality of the Bloemspruit and its tributaries is poor. Several anthropogenic activities along the stream may have attributed to the poor status of the Bloemspruit water quality. These include the waste water treatment plant (WWTP), agricultural farming of animals and pastures as well as formal and informal settlements. Therefore, humans that use the water are at risk of being exposed to water-borne pathogens caused by high levels of E. coli and coliforms in the water. These pathogens can cause gastrointestinal diseases, such as diarrhoea, typhoid fever, cholera and other conditions including ear and eye infections. Additionally, the animals are also in danger of contracting diseases transmitted by this polluted water.