Browsing by Author "Gashe, B.A."
Now showing items 1-4 of 4
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Mpuchane, S.; Allotey, J.; Matsheka, I.; Simpanya, M.; Coetzee, S.; Jordaan, A.; Mrema, N.; Gashe, B.A. (ICIPE - African Insect Science for Food and Health, http://journals.cambridge.org/action/displayJournal?jid=JTI, NaN, 2006)[more][less]
Abstract: Domestic cockroaches Blattella germanica were trapped from various homes in Gaborone, Botswana using ‘Dyroach’ traps. Isolations of bacteria, yeasts and moulds were done on external body parts and on the faecal pellets using various selective media. Body parts of cockroaches were also fixed with OsO4 vapour for 24 h, sputter coated with gold under special conditions and examined in a Phillips (1) XL30 ESEM in low vacuum mode. Awide spectrum of bacteria including common food spoilage and pathogenic organisms, such as Bacillus spp., Staphylococcus spp., Escherichia coli, Pseudomonas spp., Enterobacter spp., Klebsiella spp., Erwinia spp. Salmonella sp., Shigella sp. and Serratia spp. were isolated. Yeasts commonly associated with food spoilage, such as Pichia sp., Candida sp. and Torulopsis spp. were found on many cockroaches. In addition, various groups of moulds, some associated with food spoilage and others known to produce mycotoxins, such as Aspergillus flavus, Aspergillus fumigatus and Aspergillus parasiticus were isolated. Antimicrobial sensitivities of bacterial isolates revealed resistance patterns to various agents. Since cockroaches are prevalent in homes, particularly in food preparation areas and since their body parts and faecal pellets have been found in food storage areas, concern about their impact on food quality and safety is raised and possible control measures including education of communities on proper sanitation are suggested. URI: http://hdl.handle.net/10311/1005 Files in this item: 1
Matsheka_IJTIS_2006.pdf (193.3Kb) -
Baloi, B.; Matsheka, M.I.; Gashe, B.A. (Global Science Books, http://www.globalsciencebooks.info/, NaN, 2011)[more][less]
Abstract: Halophilic bacteria from the Makgadikgadi salt pans in north central Botswana were isolated using culture-dependent methods. Polymerase chain reaction (PCR) amplification of the 16S rRNA gene and phylogenetic analysis were used to identify the strains. Culturing was done aerobically in six different complex salt media. Salt concentrations used were 1Halophilic bacteria from the Makgadikgadi salt pans in north central Botswana were isolated using culture-dependent methods. Polymerase chain reaction (PCR) amplification of the 16S rRNA gene and phylogenetic analysis were used to identify the strains. Culturing was done aerobically in six different complex salt media. Salt concentrations used were 15, 20, 25 and 30% (2.6, 3.4, 4.3 and 5.1 M, respectively) NaC1, at pH 7.2 to pH 8.0. Four colony morphology types were isolated in axenic cultures comprising Gram-positive cells. Universal bacterila primers were used to amplify 16S rDNA from chromosomal DNA isolated from three of the four distinct colony groups. Restriction enzyme digest analysis of the 16S rDNA revealed seven RFLP types. Five of the RFLP types were subjected to sequencing. Comparison of the 16S rDNA sequence alignment to reference sequence data bases showed samples S2012A3, S2012B2 and S2012B3 to have between 95 and 99% homology to Bacillus sp. BH 164 and Bacillus sp. HS 136T, a novel species recently described as Bacillus persepolensis. Isolate S4102D4 showed 95 to 99% homology to Thalassobacillus sp. JY0201 and Thalassobacillus sp. FIB228 and Halobacillus sp. MO56 species. All five isolates had at least 95% similarity to published sequences implying they could be species within the described genera. A sub-tree drawn to compare the isolates indicated two phyletic lines with S4102D4 being an outlying strain and S2012A3, S2012B and S2012B3 being a closely related clonal group all of which branch from Bacillus sp. BH 164. Pending conclusive culture, biochemical and polar lipid composition data these microorganisms are regarded as previously un-described and therefore novel species of halophilic bacteria. URI: http://hdl.handle.net/10311/920 Files in this item: 1
Matsheka_AJPSB_2011.pdf (525.8Kb) -
Moyo, S.; Gashe, B.A.; Collison, E.K.; Mpuchane, S. (Elsevier / www.elsevier.com/locate/ijfoodmicro, NaN, 2003)[more][less]
Abstract: This present study was undertaken to find optimum conditions of pH, temperature and, period of incubation for the pectinolytic activity of Kluyveromyces wickerhamii isolated from rotting fruits and to assess the effect of these factors by use of response surface methodology (RSM). A central composite rotatable design was used as an experimental design for the analysis of the allocation of treatment combinations. A second order polynomial regression model was fitted and was found adequate, with an R2 of 0.94469 ( P < 0.001). The effects of temperature and pH were the most significant factors in influencing enzyme production. Estimated optimum conditions were as follows: pH 5.0, temperature, 32 jC and an incubation period of 91 h. Pectinesterase (PE), pectin lyase (PL), and cellulase activities were not detected. Pectinase production was partially constitutive. Pectin was degraded by the isolated strain of K. wickerhamii in the current study, and the pectinolytic activity is referred to as polygalacturonase (PG) activity. Crude enzyme extract was thermostable at various temperatures and, stimulated by the presence of Ca2 + ions but inhibited by other ions like Mg2 +, Zn2 +, Co2 +, Mn2 + and Na+. URI: http://hdl.handle.net/10311/228 Files in this item: 2
license.txt (1.998Kb)Moyo_IJFM_2003.pdf (2.012Mb) -
Morobe, I.C.; Obi, C.L.; Nyila, M.A.; Gashe, B.A.; Matsheka, M.I. (Academic Journals, http://www.academicjournals.org/AJB, NaN, 2009)[more][less]
Abstract: Listeria monocytogenes is known to cause epidemic and sporadic cases of listeriosis. The present study investigated the occurrence, antibiograms and molecular serotypes of the organism in various retail outlets in Gaborone, Botswana. Food samples were obtained randomly from selected supermarkets and street vendors in 5 geographical areas of Gaborone from May, 2007 to September 2007. L. monocytogenes was isolated and positively identified by using morphological and biochemical tests. From a total of 1324 food samples tested 57(4.3 %) were positive for L. monocytogenes. Out of the 57 isolates of L. monocytogenes 7 (12.3%), 3 (5.3%), 0 (0%), 27 (47.4%) and 20 (35.1%) were isolated from cheese, raw milk, meat (biltong), frozen cabbage and salad (coleslaw), respectively. From the 5 geographical areas selected for sampling in this study, Gaborone South recorded the highest number 19 (33.3%) of L. monocytogenes isolates while Gaborone West recorded the least, 7 (12.3%). The findings in this study reveal the presence of L. monocytogenes serotypes 1/2a and 1/2b in ready to eat food and highlight the need for education and training programmes in food safety in Gaborone, Botswana. URI: http://hdl.handle.net/10311/996 Files in this item: 1
Morobe_AJB_2009.pdf (86.64Kb)
Now showing items 1-4 of 4