Bacteriocin and cellulose production by lactic acid bacteria isolated from West African soft cheese

Sixteen colonies of lactic acid bacteria (LAB) were selected and screened for their ability to produce bacteriocin by agar well diffusion method using the supernatant of centrifuged test cultures. Fourisolates inhibited the growth of Listeria monocytogenes and Escherichia coli. Lactobacillus plantarum (6) and Lactobacillus brevis (5) were the most dominant species. The remaining were Lactobacilluslactis (2), Streptococcus lactis (2) and Lactobacillus fermentum (1). Lactobacillus spp. accounted for 87.5% of all isolates. LAB4 (Lactobacillus plantarum) showed some levels of antimicrobial activity after 15, 20 and 25 min heat treatments at 100oC against Listeria monocytogenes . While antimicrobial activity of LAB70 (Lactobacillus lactis) was against both Listeria monocytogenes (after 20 and 25 min)and E. coli 0157:H7 (after 15, 20 and 25 min) heat treatment at 100oC. All the lactic acid bacteria used in this study produced cellulose. The correlation between cellulose production (an adhesion factor) and bacteria growth was highly significant after 72 h of incubation having a R2 = 0.800. This study offers useful information on growth and cellulose production as factors affecting the efficacy of bacteriocin produced by these strains which could be good for biopreservation

Costs, climate and contamination: Three drivers for city-wide sanitation investment decisions

Significant progress is needed, in both large cities and small towns, to meet the ambitious targets set at international and national levels relating to universal access to safely managed sanitation. There has been increased recognition in the urban sanitation sector that in rapidly growing cities, there is unlikely to be a single centralized sanitation solution which can effectively deliver services to all demographics, and that heterogeneous approaches to urban sanitation are required. At the same time, due to competing investment priorities, there is a greater focus on the need for sanitation investments to address multiple objectives. However, calls for more informed sanitation planning and a more dynamic and disaggregated approach to the delivery and management of sanitation services have had limited impacts. This is in part due to the complexity of the drivers for sanitation investment, and the difficulties involved in identifying and addressing these multiple, often conflicting, goals. This paper examines three potential drivers of citywide sanitation decision-making – public health, sustainability and economic performance – via the three proxies of contamination, climate change and costs. It examines the importance of each driver and proxies, how they are considered in investment decisions, the current state of knowledge about them, and priority aspects to be included in decisions. At present, while public health is a common driver for improving sanitation, there are significant gaps in our understanding of fecal contamination spread and exposure, and how to select sanitation solutions which can best address them. Climate change is sometimes seen as a low priority for the sanitation sector given the immediacy and scale of existing challenges and the uncertainty of future climate predictions. However, potential risks are significant, and uninformed decisions may result in greater costs and increased inequalities. Cost data are sparse and unreliable, and it is challenging to build robust cost-effectiveness analyses. Yet these are needed to compare citywide options based on least-cost over their full life cycle. This paper provides insights into how existing evidence on contamination, climate change and costs can inform decisions on sanitation investments and help chart a sustainable way forward for achieving citywide services

Formation of biofilm by strains of Listeria monocytogenes isolated from soft cheese 'wara' and its processing environment

Quantification of biofilm formation by 40 Listeria monocytogenes strains from wara soft cheese and its processing environment was assessed on glass vials surfaces. Attachement to glass surface wasquantified using a crystal violet binding assay. All the 40 strains produced biofilms after 48 and 72 h incubation at 37oC. No biofilms were formed at 24 h incubation but biofilm formation increased withincubation period in 20 out of the 40 strains. R2 values obtained were 0.0166 and 0.1193 respectively for biofilm formation between 24 and 48 h and 24 and 72 h incubation periods, respectively (P-values o

A Systematic Review and Meta-Analysis of Fecal Contamination and Inadequate Treatment of Packaged Water

<div><p>Background</p><p>Packaged water products provide an increasingly important source of water for consumption. However, recent studies raise concerns over their safety.</p><p>Objectives</p><p>To assess the microbial safety of packaged water, examine differences between regions, country incomes, packaged water types, and compare packaged water with other water sources.</p><p>Methods</p><p>We performed a systematic review and meta-analysis. Articles published in English, French, Portuguese, Spanish and Turkish, with no date restrictions were identified from online databases and two previous reviews. Studies published before April 2014 that assessed packaged water for the presence of <i>Escherichia coli</i>, thermotolerant or total coliforms were included provided they tested at least ten samples or brands.</p><p>Results</p><p>A total of 170 studies were included in the review. The majority of studies did not detect fecal indicator bacteria in packaged water (78/141). Compared to packaged water from upper-middle and high-income countries, packaged water from low and lower-middle-income countries was 4.6 (95% CI: 2.6–8.1) and 13.6 (95% CI: 6.9–26.7) times more likely to contain fecal indicator bacteria and total coliforms, respectively. Compared to all other packaged water types, water from small bottles was less likely to be contaminated with fecal indicator bacteria (OR = 0.32, 95%CI: 0.17–0.58) and total coliforms (OR = 0.10, 95%CI: 0.05, 0.22). Packaged water was less likely to contain fecal indicator bacteria (OR = 0.35, 95%CI: 0.20, 0.62) compared to other water sources used for consumption.</p><p>Conclusions</p><p>Policymakers and regulators should recognize the potential benefits of packaged water in providing safer water for consumption at and away from home, especially for those who are otherwise unlikely to gain access to a reliable, safe water supply in the near future. To improve the quality of packaged water products they should be integrated into regulatory and monitoring frameworks.</p></div