Impact of solid surface hydrophobicity and micrococcal nuclease production on Staphylococcus aureus Newman biofilms

Staphylococcus aureus is commonly associated with biofilm-related infections and contributes to the large financial loss that accompany nosocomial infections. The micrococcal nuclease Nuc1 enzyme limits biofilm formation via cleavage of eDNA, a structural component of the biofilm matrix. Solid surface hydrophobicity influences bacterial adhesion forces and may as well influence eDNA production. Therefore, it is hypothesized that the impact of Nuc1 activity is dependent on surface characteristics of solid surfaces. For this reason, this study investigated the influence of solid surface hydrophobicity on S. aureus Newman biofilms where Nuc1 is constitutively produced. To this end, biofilms of both a wild-type and a nuc1 knockout mutant strain, grown on glass, salinized glass and Pluronic F-127-coated silanized glass were analysed. Results indicated that biofilms can grow in the presence of Nuc1 activity. Also, Nuc1 and solid surface hydrophobicity significantly affected the biofilm 3D-architecture. In particular, biofilm densities of the wild-type strain on hydrophilic surfaces appeared higher than of the mutant nuc1 knockout strain. Since virulence is related to bacterial cell densities, this suggests that the virulence of S. aureus Newman biofilms is increased by its nuclease production in particular on a hydrophilic surface

Groundwater quality, sanitation and vulnerable groups: case study of Bawku East District

The effect of human hygienic behaviour on the quality of groundwater was investigated using standard methods for trace elements and bacteria pollution indicators in Bawku East District of Ghana in 2006. No iron was detected in water; manganese levels were higher in wells than boreholes and fluoride levels exceeded the WHO standard (1.5mg/l) by 0.5-1.0mg/l in one well and a borehole at Bawku. Typical bacteria numbers deviated from normal trends (i.e.1014, 1011, 108, and 104 for total coliforms, faecal coliforms, E. coli and enterococci in the well water compared to 106, 105, 103 and 102 in the boreholes respectively). The six UNICEF boreholes were within the WHO guideline of zero helminthes (100-1 ml) but the wells were not. Hence, quality of the boreholes was higher than the wells for drinking purposes

Pointed gaps in the provision, quality, patronage and management of toilet facilities in Bawku East District

The objective was to assess the level of sanitation and hygiene with baseline information on the impact of onsite sanitation facility development on public health in the Bawku East District using hundred and sixty eight (n=168) respondents from five randomly selected communities according to UNICEF water and sanitation support programs for a survey. Public latrine alone accounted for 43% patronage of toilet facilities in the district. Unfortunately, about 70% of the population who preferred household toilets rather patronized open defecation due to poverty and inadequate good toilet facilities at user ratio of 1: over 500 people with very low seat capacities. Among the subjects encountered, 42% were unskilled labourers whilst 27% students, who, could hardly afford the comfort of household toilet facilities

Nanogels:A novel approach in antimicrobial delivery systems and antimicrobial coatings

The implementation of nanotechnology to develop efficient antimicrobial systems has a significant impact on the prospects of the biomedical field. Nanogels are soft polymeric particles with an internally cross-linked structure, which behave as hydrogels and can be reversibly hydrated/dehydrated (swollen/shrunken) by the dispersing solvent and external stimuli. Their excellent properties, such as biocompatibility, colloidal stability, high water content, desirable mechanical properties, tunable chemical functionalities, and interior gel-like network for the incorporation of biomolecules, make them fascinating in the field of biological/biomedical applications. In this review, various approaches will be discussed and compared to the newly developed nanogel technology in terms of efficiency and applicability for determining their potential role in combating infections in the biomedical area including implant-associated infections

farmers knowledge and practices in the management of insect pests of leafy amaranth in kenya

Abstract Amaranth (Amaranthus L.) species are grown for their grain or leaves and contribute to farmers' livelihoods and nutritional food security. Leafy amaranth (LA) is consumed widely as a vegetable in Kenya. An assessment of current farmers' knowledge of pest management practices provides information about future educational needs. Six-hundred LA farmers were interviewed, focus group discussions with farmers, and interviews with key informants were completed in four Kenyan counties. The majority (71%) of survey respondents grew LA on less than 0.25 acre (<0.1 ha) and 59.2% were female. Constraints of LA production differed by counties surveyed. Farmers indicated insects and birds were important in Kiambu and Kisumu counties, whereas in Vihiga and Kisii, capital, markets, and land area for production were important. Farmers stated and ranked importance of the insects they observed during LA production. Eighty-seven percent stated aphids (Hemiptera: Aphididae), as a major pest and 96.8% ranked aphids as the number-one insect pest of LA in all four counties. Two other pests of LA included cotton leafworm, Spodoptera littoralis (Lepidoptera: Noctuidae) (0.8%) and spider mites, Tetranychus spp (Trombidiformes; Tetranychidae) (0.7%). Forty-two percent of all LA farmers managed aphids, with 34% using synthetic insecticides and 8% using nonsynthetic methods. Biological controls and host-plant resistance were not mentioned. Educational programs that train farmers about integrated pest management (IPM) in LA production are needed. Future research should determine successful IPM strategies for aphids on LA to reduce insecticide use and improve sustainability and nutritional food security for small-landholder farmers and consumers

Partners in Impact Assessment Summary Proceedings of the ICRISAT/NARS Workshop on Methods and Joint Impact Targets in Western and Central Africa 3-5 May 1995

Regional workshops were held at Sadore, Niger and Samanko, Mali, to evaluate the joint impact of ICRISAT and National Agricultural Research Systems (NARS) in Western and Central Africa. Twentyone scientists from ICRISAT and the national program in Cameroon, Chad, and Niger participated in the workshop at Sadore. The Samako workshop was at tended by 18 scientists from ICRISAT, NARS collaborators in Burkina Faso and Mali, INSAH and the West and Central African Sorghum Research Network (WCASRN) . National program representatives identified specific jointly-developed technologies that should be targeted for impact assessment. Methodological approaches for measuring welfare benefits to consumers and producers were discussed and illustrated wi th case studies. Minimum dataset requirements were outlined and protocols for case studies on technologies targeted by NARS partners were develope

Collaborative effort to operationalize the gender transformative approach in the Barotse Floodplain

Agricultural interventions that aim at alleviating rural poverty have important gender implications. The paper explores a Gender Transformative Approach recognizing that fishing, post- harvest processing, and trading are all gendered activities. On the Barotse Floodplain (Zambia) women are relegated to perform tasks within less profitable nodes of the fish value chain. The assessment of ecosystem services in a select number of Aquatic Agricultural Systems (AAS) focal communities included women’s and men’s perspectives and diverse provisioning, regulating and cultural ecosystem services.Cultivate Africa’s Future Fund (CULTIAF

Genomic epidemiological analysis identifies high relapse among individuals with recurring tuberculosis and provides evidence of household recent TB transmission in Ghana

OBJECTIVE: We investigated the cause of recurring tuberculosis (rcTB) among pulmonary TB participants recruited from a prospective population-based study conducted between July 2012 and December 2015. METHODS: Mycobacterium tuberculosis complex isolates obtained from rcTB cases were characterized by standard mycobacterial genotyping tools in addition to whole genome sequencing, followed by phylogenetic analysis to assess strain relatedness. RESULTS: A greater proportion (58.3%, 21/36) of individuals with rcTB episodes had TB recurrence within 12 months post treatment. Only 19.4% (7/36) of participants with rcTB harbored a strain with isoniazid (INH) resistance at baseline of which 29% (2/7) were additionally resistant to rifampicin. However, 27.8% (10/36) harbored an INH resistant strain upon recurring of which 40% (4/10) were MDR-TB strains. Recurrent TB was attributed to relapse (same strain) in 75.0% (27/36) of participants with 25.0% (9/36) attributed to re-infection. CONCLUSION: Our findings indicate that unresolved previous infection due to inadequate treatment may be the major cause of rcTB

Combined Inflammatory and Metabolic Defects Reflected by Reduced Serum Protein Levels in Patients with Buruli Ulcer Disease

Buruli ulcer is a skin disease caused by Mycobacterium ulcerans that is spreading in tropical countries, with major public health and economic implications in West Africa. Multi-analyte profiling of serum proteins in patients and endemic controls revealed that Buruli ulcer disease down-regulates the circulating levels of a large array of inflammatory mediators, without impacting on the leukocyte composition of peripheral blood. Notably, several proteins contributing to acute phase reaction, lipid metabolism, coagulation and tissue remodelling were also impacted. Their down-regulation was selective and persisted after the elimination of bacteria with antibiotic therapy. It involved proteins with various functions and origins, suggesting that M. ulcerans infection causes global and chronic defects in the host’s protein metabolism. Accordingly, patients had reduced levels of total serum proteins and blood urea, in the absence of signs of malnutrition, or functional failure of liver or kidney. Interestingly, slow healers had deeper metabolic and coagulation defects at the start of antibiotic therapy. In addition to providing novel insight into Buruli ulcer pathogenesis, our study therefore identifies a unique proteomic signature for this disease