Applied Biology and Biochemistry Conference Papers
Permanent URI for this collection
Browse
Recent Submissions
- ItemGenomic Analysis of Enterococcus spp. Isolated From a Wastewater Treatment Plant and Its Associated Waters in Umgungundlovu District, South Africa(Frontiers in Microbiology, 2021-06-14) Mbanga, J.; Amoako, D.G.; Abia, A.L.; Allam, M.; Ismail, A.; Essack, S.Y.We investigated the antibiotic resistome, mobilome, virulome, and phylogenomic lineages of Enterococcus spp. obtained from a wastewater treatment plant and its associated waters using whole-genome sequencing (WGS) and bioinformatics tools. The whole genomes of Enterococcus isolates including Enterococcus faecalis (n = 4), Enterococcus faecium (n = 5), Enterococcus hirae (n = 2), and Enterococcus durans (n = 1) with similar resistance patterns from different sampling sites and time points were sequenced on an Illumina MiSeq machine. Multilocus sequence typing (MLST) analysis revealed two E. faecalis isolates that had a common sequence type ST179; the rest had unique sequence types ST841, and ST300. The E. faecium genomes belonged to 3 sequence types, ST94 (n = 2), ST361 (n = 2), and ST1096 (n = 1). Detected resistance genes included those encoding tetracycline [tet(S), tet(M), and tet(L)], and macrolides [msr(C), msr(D), erm(B), and mef(A)] resistance. Antibiotic resistance genes were associated with insertion sequences (IS6, ISL3, and IS982), and transposons (Tn3 and Tn6000). The tet(M) resistance gene was consistently found associated with a conjugative transposon protein (TcpC). A total of 20 different virulence genes were identified in E. faecalis and E. faecium including those encoding for sex pheromones (cCF10, cOB1, cad, and came), adhesion (ace, SrtA, ebpA, ebpC, and efaAfs), and cell invasion (hylA and hylB). Several virulence genes were associated with the insertion sequence IS256. No virulence genes were detected in E. hirae and E. durans. Phylogenetic analysis revealed that all Enterococcus spp. isolates were more closely related to animal and environmental isolates than clinical isolates. Enterococcus spp. with a diverse range of resistance and virulence genes as well as associated mobile genetic elements (MGEs) exist in the wastewater environment in South Africa.
- ItemEvaluation 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.
- ItemIntegrated 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.
- ItemAflatoxin 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.
- ItemA 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.