The application of epidemiology to computer viruses

Recently there have been a number of news reports on computer “viruses”. This column is intended to give you an understanding of viruses and the issues that they raise.     

ENZYMATIC AND SOME BIOCHEMICAL CHANGES ASSOCIATED WITH THE PRODUCTION OF "KANTONG," A TRADITIONAL FERMENTED CONDIMENT IN NORTHERN GHANA

This paper reports on the activities of three major food enzymes (amylase, protease and lipase) during the traditional fermentation of Ceiba pentandra seeds into "kantong," a condiment used in Northern Ghana for soups. Samples were taken at periodic intervals during the fermentation, and enzyme activities and other parameters were determined. All enzyme activities increased steadily during fermentation, but leveled off when the fermentation was stopped at 48 h and the product dried. The increase in enzyme activities led to significant reductions in the levels of fiber and lipids, whereas protein and ash contents increased significantly ( P <  0.05). The fermentation produced significant increases in the concentration of all the amino acids. The process was acidic, as the pH dropped from 6.95 to 4.91. "Kantong," used in poor homes as substitute for meat or fish for flavoring soups, can serve as a nutritious condiment in the diet and its consumption should be encouraged.

PRACTICAL APPLICATIONS

"Kantong" is a traditional fermented condiment produced by the fermentation of the seeds of silk cotton (Ceiba pentandra). It is widely used in Northern Ghana as flavoring for soups and stews. However, no scientific studies about the fermentation process have been carried out. A scientific understanding of the fermentation process will enable a technological improvement on the process, either by the use of starter cultures or the addition of exogenous enzymes to the medium for the substrate conversion. The work also provided information on the nutritional value of the product, and thus its role in providing food security to the people who use it. The microbiological aspects of the fermentation are described under a different topic.     

Determination of mineral element composition of Ayoyo,Baobab and Dandelion vegetable green leaves in Ghana using instrumental neutron activation analysis

The present investigation was undertaken to determine the nutritional compositions (mineral elements) of three green leafy vegetable; Dandelion (Taraxacum Officinale), Ayoyo (Corchorus Olitorius) and Baobab (Adasonia Digitata). The ultimate goal is to improve nutrition and health by advocating for increased consumption of indigenous green leafy vegetables with an objective to increasing public acceptance, awareness and utilization. The mineral elements were determined using instrumental neutron activation analysis, over 20 elements were detected. However, 14 mineral elements were quantitatively evaluated on the basis of k₀-method and relative comparator method. The leaves were characterized with high concentration of Mg, Ca, Cl and K, and substantive amount of Mn, Fe, Zn, Cu and I. The composition of the mineral elements and its respective percent contribution to Recommended Dietary Allowance/Adequate Intake (RDA/AI) for various life groups indicates that reasonable consumption of any of the three green leafy vegetable can contribute substantive amount of daily nutritional requirement for minor nutrients like; I, Cu, Zn, Mn, and Fe as well as major nutritional (Mg, Ca, Cl and K) needs for all life groups. Each of the leaves was also characterize with high K/Na ratios. Tolerable upper intake levels (UL) analysis also showed no significant abuse for the mineral elements determined. Other potential toxic elements (As, Cd and Hg) and non-nutritional minerals (Br, V, Al and Ba) were either not detected or were found in low concentrations.     

Cultural factors constraining the introduction of family planning among the Kassena-Nankana of northern Ghana

This study presents a focus group investigation of reasons why women in a rural, Sahelian community are reluctant to adopt family planning even when convenient services are made freely available. First, women opting to practice contraception must do so at considerable risk of social ostracism or familial conflict. Implementing individual preference is something that must be done without the support of others. Second, few women view personal decisions about contraceptives as theirs to make. Women and children are the property of the corporate family-kin and community militate against reproductive control. Third, although children are highly valued for a variety of economic, social, and cultural reasons, mortality risks remain extremely high. Low fertility imposes the unacceptable risk that a woman will have no surviving children at the end of her reproductive life. Taken together, these findings attest to the inadequacy of service strategies focused on the contribution of distribution, individual agency, or personal choice. Outreach should also build a sense of community legitimacy for the program, collective health action, and traditional leadership support for family planning behavior.     

Anonymising group data sharing in opportunistic mobile social networks

Wireless Networks - The security and privacy risks of group users are major concerns in opportunistic mobile social network (OMSN) platforms, especially when the users share data publicly in a...     

Identification of lactic acid bacteria isolated during traditional fura processing in Ghana

Fura is a millet-based spontaneously fermented dumpling produced and consumed in parts of West Africa, particularly Nigeria, Burkina Faso and Ghana. From eight traditional fura production sites in northern Ghana, 862 lactic acid bacteria were isolated and identified to species level using a combination of genotypic and phenotypic methods including (GTG)₅-based PCR fingerprinting and 16S rRNA gene sequencing, multiplex PCR by means of recA gene sequence comparison, conventional morphological characteristics and carbohydrate fermentation profiling. During millet dough fermentation, pH decreased from 5.6–6.4 to 4.1–3.7 and total lactic acid bacteria (LAB) counts increased from 4.4–5.3 to 7.9–9.2 log₁₀ (cfu/g). The initial stages of the fermentation were characterized by co-dominance of homo- and heterofermentative species of Pediococcus acidilactici, Weisella confusa, Lactobacillus fermentum, Lactobacillus reuteri, Lactobacillus salivarius, and Lactobacillus paraplantarum whereas L. fermentum was dominating at the end of the fermentation. L. fermentum was predominant in all fermentations (p < 0.05) and a high uniformity was observed among production sites regarding the dominance of L. fermentum. L. fermentum and W. confusa were isolated in all production sites and almost at all fermentation stages indicating that they are indigenous to traditional fura processing. The other LAB bacteria species which comprised a minor proportion of the total LAB occurred occasionally and in an irregular pattern among the production sites.     

Investigation of the diversity and safety of the predominant Bacillus pumilus sensu lato and other Bacillus species involved in the alkaline fermentation of cassava leaves for the production of Ntoba Mbodi

The objective of the study was to investigate the identity, diversity, and safety of the Bacillus population involved in the fermentation of cassava (Manihot esculenta Crantz) leaves for the production of Ntoba Mbodi, a Congolese food. Ninety bacteria were identified by phenotyping and genotyping using ITS-PCR, rep-PCR, and sequencing of the 16S rRNA, gyrA, gyrB and rpoB genes. Moreover, the isolates were screened for the presence of genes coding for haemolytic (HblC, HblD) and non-haemolytic enterotoxins (NheA, NheB and NheC), cytotoxin K (CytK) and emetic toxin (EM1) as well as their ability to produce haemolysin.The investigations revealed the predominance (72.2%) of species of the Bacillus pumilus group i.e. B. safensis (48), B. pumilus (7), and B. pumilus sensu lato (10). Other species of Bacillus including B. cereus sensu lato (11), B. megaterium (4), B. subtilis (4), B. amyloliquefaciens (2), B. siamensis (2), B. licheniformis (1) and Lysinibacillus louembei (1) were also identified. Haemolytic, non-haemolytic and cytokin toxin genes were detected in the B. cereus strains which were also able to produce haemolysin. The emetic toxin gene was not detected in any isolates. The toxin genes screened were not detected in any of the non B. cereus species.     

Probiotic potential of Saccharomyces cerevisiae and Kluyveromyces marxianus isolated from West African spontaneously fermented cereal and milk products

The yeast species Saccharomyces cerevisiae and Kluyveromyces marxianus are associated with fermentation of West African indigenous foods. The aim of this study was to characterize potential probiotic properties of S. cerevisiae and K. marxianus isolates from the West African milk products lait caillé and nunu and a cereal-based product mawè. The strains (14 in total) were identified by 26S rRNA gene sequencing and characterized for survival at gastrointestinal stress (bile salts and low pH) and adhesion to Caco-2 intestinal epithelial cells. Selected yeast isolates were tested for their effect on the transepithelial electrical resistance (TEER), using the intestinal epithelial cell line Caco-2 and for maintenance of intracellular pH (pH_i) during perfusion with gastrointestinal pH (3.5 and 6.5). All tested yeasts were able to grow in bile salts in a strain-dependent manner, exhibiting a maximum specific growth rate (μ_max) of 0.58–1.50 h⁻¹. At pH 2.5, slow growth was observed for the isolates from mawè (μ_max of 0.06–0.80 h⁻¹), whereas growth of yeasts from other sources was mostly inhibited. Yeast adhesion to Caco-2 cells was strain specific and varied between 8.0% and 36.2%. Selected strains of S. cerevisiae and K. marxianus were able to maintain the pH_i homeostasis at gastrointestinal pH and to increase TEER across the Caco-2 monolayers, indicating their potential to improve intestinal barrier functions. Based on overall results, strains of K. marxianus and S. cerevisiae from mawè exhibited the highest probiotic potential and might be recommended for further development as starter cultures in West African fermented products.     

Taxonomic and molecular characterization of lactic acid bacteria and yeasts in nunu,a Ghanaian fermented milk product

Produced from raw unpasteurized milk, nunu is a spontaneously fermented yoghurt-like product made in Ghana and other parts of West Africa. Despite the importance of nunu in the diet of many Africans, there is currently only limited information available on the microorganisms associated with nunu processing. With the aim of obtaining a deeper understanding of the process and as a first step towards developing starter cultures with desired technological properties for nunu production, a microbiological characterization of nunu processing in three different towns in the Upper East region of Ghana, namely Bolgatanga, Paga and Navrongo, was carried out. Lactic acid bacteria (LAB) and yeasts associated with nunu processing were isolated and identified using a combination of pheno- and genotypic methods including morphological and carbohydrate fermentation tests, (GTG)₅-based rep-PCR, multiplex PCR, and 16S and 26S rRNA gene sequencing. The LAB counts during nunu processing increased from 4.5 ± 0.4 log cfu/ml at 0 h to 8.7 ± 1.8 log cfu/ml at 24 h of fermentation while yeasts counts increased from 2.8 ± 1.2 log cfu/ml at 0 h to 5.8 ± 0.5 log cfu/ml by the end of fermentation. Lactobacillus fermentum was the dominant LAB throughout the fermentations with Lactobacillus plantarum and Leuconostoc mesenteroides playing prominent roles during the first 6–8 h of fermentation as well. Less frequently isolated LAB included Lactobacillus helveticus, Enterococcus faecium, Enterococcus italicus, Weissella confusa and a putatively novel Lactococcus spp. The yeasts involved were identified as Candida parapsilosis, Candida rugosa, Candida tropicalis, Galactomyces geotrichum, Pichia kudriavzevii and Saccharomyces cerevisiae with P. kudriavzevii and S. cerevisiae being the dominant yeast species.