Applied Biology and Biochemistry Conference Papers

Permanent URI for this collection

http://196.220.97.103:4000/handle/123456789/74

Browse

Recent Submissions

Now showing 1 - 5 of 34
  • No Thumbnail Available
    Item
    Evaluation of test-kits for the detection of Escherichia coli O157 in raw meats and cattle faeces
    (2012) Nyati, H.; Heuvelink, A.; Van Heerwaarden, C.; Zwartkruis, A.
    Escherichia coli O157 detection limits in artificially contaminated beef and cattle faeces samples were determined using Dynabeads anti E. coli O157 immunomagnetic beads, VIDAS-UP, VIDAS-ICE, and real-time PCR (GeneDisc and LightCycler) systems. Dynabeads anti-E. coli O157 immunomagnetic separation (IMS) and the GeneDisc cycler were the most sensitive methods, and could detect an initial 1 CFU in 25g beef samples after 6h of incubation in modified tryptone soya broth with novobiocin (mTSB+n) or buffered peptone water (BPW). The VIDAS-UP method could detect an initial 10 CFU, while VIDAS-ICE and the LightCycler methods could only detect an initial 100 CFU. Higher detection rates were achieved with 18 hour incubations, where an initial 1 CFU in a 25g sample could be detected with all five methods. For cattle faeces enrichments, Dynabeads anti-E. coli O157 IMS could detect an initial 1 CFU after a 6 h incubation in mTSB+n, while the VIDAS-UP and VIDAS-ICE methods could detect an initial 10 CFU and both PCR methods could only detect an initial 100 CFU. Detection rates were lower in BPW, compared to mTSB+n, with thresholds of 100 CFU for VIDAS-ICE, VIDAS-UP and GeneDisc methods, and >100 CFU for the LightCycler method.
  • No Thumbnail Available
    Item
    Integrated Municipal Solid Waste Management System (IMSWMS)
    (2016) Nleya, M.; Gunda, L.; Chisadza, Z.; Manyuchi, M.
    Rapid population growth, industrialization, urbanization and technology trends have led to a sharp increase in solid waste generation. Some municipalities are still using the conventional approach to solid waste management leading to solid waste becoming a sight everywhere. It is important to monitor solid waste collection and record the information pertaining to collection time, area and other related data from a central location. For this purpose, an Integrated Municipal Solid Waste Management System (IMSWMS) is presented and discussed in this paper. The system ensures solid waste reduction through proper collection monitoring, waste intelligence initiatives and environmental education. It is an embedded system incorporating global positioning system (GPS), radio frequency identification (RFID) technology, which is interfaced with a microcontroller and a web based graphical user interface (GUI) that can be accessed from anywhere. The web based GUI allows real time interaction of the central office with waste collection processes and residents.
  • No Thumbnail Available
    Item
    Aflatoxin carryover during large scale peanut butter production.
    (Scientific Research Publishing, 2011) Andrew H, S.; Kudzayishe J, M.; Nozipo, N.
    Peanut butter was monitored for aflatoxin contamination at different stages during its large-scale production starting from raw shelled peanuts up to the final product. Twenty five samples, weighing 2 kg each, were taken from each of the following stages: roasting at 160?C, blanching/de-skinning and grinding. The sub-samples were ground, thoroughly mixed and further reduced by the quartering technique until a 1 kg sub-sample was obtained. This was then analyzed for aflatoxins using reverse phase HPLC incorporating pre-column trifluoroacetic acid derivatization. The results showed a total aflatoxin percentage reduction of 51% after roasting, 27% after blanching/de-skinning followed by a further 11% after grinding to make peanut butter. This meant that there was a cumulative total reduction of 89% of aflatoxin concentration during the production process of peanut butter. These results show that there is a significant reduction of aflatoxin levels at the roasting and blanching stages in the process of producing peanut butter.
  • No Thumbnail Available
    Item
    A study of scavenging poultry gastrointestinal and ecto-parasites in rural areas of Matebeleland Province, Zimbabwe.
    (Asian Network for Scientific Information, 2010) Dube, S.; Zindi, P.; Mbanga, J.; Dube, C.
    A study was carried out to determine endo and ecto-parasites in Matebeleland North and South from free range chickens (Gallus domesticus). Only adult chickens were selected for determination of parasite. For intestinal parasites microscopic studies of eggs and faecal egg counts were done using the salt floatation technique. The endo parasites encountered in the study were Tetrameres americana, Acuaria hamulosa, Ascaridia galli, Heterakis gallinarum, H. dispar, Allodapa suctoria, Capillaria annulate, Raillietina echinobothrida and R. tetragona. A commercially prepared insecticide constituted as follows (0.02% Tetamethrin, 0.03% pramethrin and 0.034% Imiprothrin) was applied for 2 seconds and feathers were then gentle unruffled so that ectoparasites could be counted and identified. Ecto parasites recorded in this study were Menopon gallinae, Menacanthus stramineus, Dermanyssus gallinae, Argas persicus, Ornithonyssus bursa, Cnemidocoptes mutans, Echidnophaga gallinacean, Gonocoites gallinae and Gonocoites hologester.
  • No Thumbnail Available
    Item
    Effects of chronic exposures of selected heavy metals on the glutathione S-transferase activity of freshwater snails Lymnaea natalensis in Zimbabwe
    (Taylor & Francis, 2019) Mnkandla, S.M.; Siwela, A.H.; Basopo, N.
    The effect of the heavy metals (cadmium, copper, mercury and lead) on snail glutathione S-transferase (GST) was investigated in 2015. Groups of Lymnaea natalensis snails were exposed to heavy metals for 28 days at concentrations reportedly found in the Mguza Dam. Water and food were changed daily. Samples were collected at days 1, 7, 14, 21 and 28 post exposure. Inhibition of GST activity, following cadmium exposures, ranged between 58 and 60%, with a decrease of 30% on day 28. When snails were exposed to copper, inhibition significantly decreased by 16%, 29%, 49% and 72% inhibition when tested on days 1, 7, 14 and 21, respectively. Inhibition on day 28 was 44%. Mercury exposures resulted in significant increases in GST inhibition, namely, 47%, 62% and 79% inhibition on days 1, 7 and 14, respectively. Inhibition on day 21 was 82%, whereas on day 28 it was significantly lower, at 29%. Concerning lead exposures, inhibition levels on day 1, 7 and 21 had mean inhibition of 60%. Inhibition on days 14 and 28 was significantly lower, with a mean inhibition of 30%. These results suggest that chronic exposures could inhibit GST activity for a certain period, after which inhibition is reduced, possibly as a result of adaptation.