Applied Biology and Biochemistry Publications
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- ItemMolecular characterization and antibiotic resistance patterns of avian fecal Escherichia coli from turkeys, geese, and ducks(Veterinary world, 2018-06) Dube, Nokukhanya; Mbanga, JoshuaBackground and Aim: Avian fecal Escherichia coli (AFEC) are considered to be the natural reservoir of pathogenic strains in extraintestinal infections as such characterization of AFEC gives insight into the spread of the potential pathogenic lineage. The aim of the study was to investigate the reservoirs of avian pathogenic E. coli (APEC) from fecal samples of healthy ducks, geese, and turkeys by determining the antibiotic resistance patterns of AFEC isolates from turkeys, geese and ducks and characterization of the isolates using virulence genes, plasmid profiles, and phylogenetic grouping. Materials and Methods: The disc diffusion method was used to determine antibiotic resistance of 100 AFEC isolates from turkeys (9), geese (29), and ducks (62) to 8 antibiotics. Molecular characterization of the isolates was done by multiplex polymerase chain reaction to investigate the presence of 12 virulence genes, plasmid profiling, and phylogenetic grouping based on the 16S rRNA sequences. Results: Antibiogram profiles indicated maximum resistance to cloxacillin (100%) and bacitracin (100%) for all AFEC isolates and high sensitivity to ciprofloxacin; however, all isolates exhibited multi-drug resistance. The AFEC isolates from turkeys (6) and geese (12) did not contain virulence genes. The frz (3.7%), sitD (29.6%), and fimH (92.5%) were detected in the duck isolates. None of the isolates had the KpsM, iutA, vat, sitA, hlyF, pstB, ompT, uvrY, and sopB genes. Plasmid profiling gave four plasmid profiles with the plasmids ranging from 1.5 to 55 kb. Phylogenetic analysis of 16S rRNA sequences revealed similarities between AFEC isolates from the different poultry species, as the isolates did not cluster according to avian species. Conclusion: AFEC isolates are potential reservoirs of APEC as they contain some of the virulence genes associated with APEC. Multidrug resistance is high in AFEC isolated from healthy birds. This is a public health concern.
- ItemCurrent Status of Mycotoxin Contamination of Food Commodities in Zimbabwe(MDPI, 2018-05-03) Nleya, N.; Adetunji, Modupeade.C; Mwanza, M.Agricultural products, especially cereal grains, serve as staple foods in sub-Saharan Africa. However, climatic conditions in this region can lead to contamination of these commodities by moulds, with subsequent production of mycotoxins posing health risks to both humans and animals. There is limited documentation on the occurrence of mycotoxins in sub-Saharan African countries, leading to the exposure of their populations to a wide variety of mycotoxins through consumption of contaminated foods. This review aims at highlighting the current status of mycotoxin contamination of food products in Zimbabwe and recommended strategies of reducing this problem. Zimbabwe is one of the African countries with very little information with regards to mycotoxin contamination of its food commodities, both on the market and at household levels. Even though evidence of multitoxin occurrence in some food commodities such as maize and other staple foods exist, available published research focuses only on Aspergillus and Fusarium mycotoxins, namely aflatoxins, deoxynivalenol (DON), trichothecenes, fumonisins, and zearalenone (ZEA). Occurrence of mycotoxins in the food chain has been mainly associated with poor agricultural practices. Analysis of mycotoxins has been done mainly using chromatographic and immunological methods. Zimbabwe has adopted European standards, but the legislation is quite flexible, with testing for mycotoxin contamination in food commodities being done voluntarily or upon request. Therefore, the country needs to tighten its legislation as well as adopt stricter standards that will improve the food safety and security of the masses.
- ItemConsumer's views and use of labels on food items sold in Bulawayo urban province, Zimbabwe(African scholarly science communication trust., 2017-11) Ncube, T.; Makurunje, S; Dube, S.Food labels are a medium by which consumers acquire knowledge about packaged foods they are considering to purchase. The label makes the first impression about a product and has a great effect on the purchasing decision for consumers. In recent years, literate consumers have become interested in nutritional issues. Lifestyle, age, dietary and safety concerns have been the contributing factors to nutritional awareness by consumers. Nutritional labels can generally have a positive impact on food consumption and may save health-care costs for those consumers with health concerns. On the other hand, for those consumers who are illiterate, price may be more important in making purchase decisions. This study intended to investigate how consumers in Bulawayo Urban Province (Zimbabwe) view and use labels on packaged food items. Seventy-five randomly selected consumers were questioned about their perceptions, attitudes and use of label information using open ended structured questionnaires. The consumers were selected on the basis of being present at the supermarkets at the time of sampling. The respondents were interviewed at different times of the day to cater for employed and unemployed people. The results obtained indicate that the extent to which food labels are used depends on factors such as price of food products, individual health needs and gender. For consumers who use food labels to make their purchase decisions, not all the information on the label is considered. Items on the labels to which the consumers responded were brand, nutritional profile and mass of product in relation to the price. The label elements which were extensively used by consumers in this study are date mark (81.3%), weight of food (89.3%) and price (77.3%). The least used element is the nutritional panel (50.7%). About 44% of the consumers were not sure about the trustworthiness of the information given on food labels. Food labels are important to a greater extent for people with special dietary requirements, while the remainder of the studied population are influenced by price in their purchase decisions. Consumers seem not to understand some of the information on the food labels because of the difficulties in interpreting what is written.
- ItemTowards improved utilization of macimbi Imbrasia belina Linnaeus, 1758 as food and financial resource for people in the Gwanda district of Zimbabwe(Zimbabwe Journal of Science & Technology, 2010) Dube, S.; Dube, C.Macimbi have two generations per annum one in November and the other in April. The November generation has a higher population per tree 206.9±56.7 than the April generation 100±25. The growth rate is the same for both generations. Each moth oviposits on one tree and the average distance between oviposited trees is 45.7±15 m. The protein and fat content of the larvae are 59% and 14% respectively. The mass of fresh full-grown ‘worms’ is 12g and they are 8-9cm long. The growth rate is increased when the relative humidity is above 75% and the temperature is 30±2oC. Worms harvested before maturity need evisceration whereas those gathered when fully grown need no evisceration. Spines begin to be effective as defense mechanism against predators after the fourth week. The pupa stage lasts 38±2 days for the November generation and 180±12 days for the April generation because of winter. It is suggested that persons be allocated woodlots as this could lead to responsible and sustainable harvesting and protection of the environment.
- ItemThe Effects of Sub Lethal Levels of Lead on Acetylcholinesterase Activity in the Rock Pigeon, (Columba Livia)(Zimbabwe Journal of Science & Technology, 2017) Muusha, Yeukai; Mnkandla, Sanele; Basopo, N.Lead is one of the most abundant heavy metals that has become widely distributed and mobilised in the environment. It exists in various forms which are bioavailable to many organisms including birds, causing physiological changes upon exposure. The aim of this study was to investigate the effects of sub lethal levels of lead on acetylcholinesterase activity in the Rock pigeon (Columba livia). Twelve free range and two pen reared (control) pigeons were collected from breeders around the city of Bulawayo and placed in separate cages. Six free range and one pen reared birds were exposed to 1.25 ppm lead acetate spiked feed and water for 72 hrs, whilst the remaining birds served as the unexposed control. Spiked feed and water were changed daily. Both the exposed and unexposed birds were sacrificed and the muscle, heart and liver tissues isolated and assayed for acetylcholinesterase activity. There was significant inhibition of enzyme activity in all tissue samples obtained from lead exposed free range birds when compared to their unexposed counterparts. In the lead exposed free range birds, muscle and liver acetylcholinesterase activity was below 0.005 μg/min/mg protein while that of the heart was in the 0.02-0.07 μg/min/mg protein range. Enzyme activity was greater than 0.1 μg/min/mg protein in the unexposed free range birds. Comparing the acetylcholinesterase activity of the lead exposed pen reared control, with that of the lead exposed free range birds, the latter demonstrated significant inhibition (p<0.05). The results therefore highlight the inhibitory effect of sub lethal levels of lead on acetylcholinesterase activity which could also be possibly enhanced by prior exposure to other environmental contaminants.