Inhibition of dehydrogenase activity in pathogenic bacteria isolates by aqueous extracts of Musa paradisiaca (Var Sapientum)

Inhibition of dehydrogenase activity in pathogenic bacteria isolates by aqueous extract from the unripe fruit peels (called the bark) and leaves of Musa paradisiaca var sapientum were investigated via dehydrogenase assay using 2,3,5-triphenyl tetrazolium chloride (TTC) as the electron acceptor. Pure cultures of Staphylococcus and Pseudomonas species were exposed to varied concentrations of theextract [0 – 2000 ìg/ml]. The extracts exhibited concentration dependent response against the tested organisms. Dehydrogenase activities (mg Formazan/mg cell dry weight/h) in the Gram-positiveStaphylococcus sp. and Gram-negative Pseudomonas sp. were 1.125 ± 0.056 and 0.740 ± 0.040, respectively, and were progressively inhibited in the pure cultures. Threshold inhibitory concentrations(IC50) of M. paradisiaca bark extract were 143.5 and 183.1 ìg/ml against Staphylococcus and Pseudomonas species, respectively, while the threshold inhibitory concentrations (IC50) of M. paradisiaca leaf extract were 401.2 and 594.6 ìg/ml, respectively. The IC100 of the leaf extract against Staphylococcus and Pseudomonas species were 1850 and 2000 ìg/ml respectively, while the bark could not completely inhibit the organisms at the tested concentrations. The bark and leaves of M. paradisiaca may be an available source of raw material for the production of chemotherapeutic agents against pathogenic bacteria

In vitro effects of metals and pesticides on dehydrogenase activity in microbial community of cowpea (Vigna unguiculata) rhizoplane

Effects of heavy metals and pesticides on cowpea (Vigna unquiculata) rhizoplane microbial community  were assessed in vitro via dehydrogenase activity. The microbial community was exposed to various concentrations of heavy metals and pesticides in a nutrient broth-glucose-2,3,5-triphenyl chloride (TTC) medium. At 0.2 mM, iron and cadmium stimulated the dehydrogenase activity of the microbialcommunity. For all the metal ions, there was progressive inhibition with each successive increase in the concentration of metal ion, reaching near 100% at 0.6, 0.8, 1.2, 0.12 and 12 mM for cobalt, cadmium,iron, mercury and nickel, respectively. Between 0.2 and 0.4 mM, zinc sharply inhibited dehydrogenase activity and at concentration above 0.4 mm, inhibition of dehydrogenase activity became lesspronounced. The order of toxicity is Hg2+ > Co2+ > Cd2+ > Zn2+ > Fe2+ > Ni2+. The herbicides Cotrazine (Atrazine 80W) and Northrin®10EC stimulated dehydrogenase activity of the microbial community at 0.2% and inhibited it at higher concentrations. The median inhibitory concentrations (IC50s) of Cotrazine(Atrazine 80W) and Northrin®10EC were 0.552 ± 0.028 and 0.593 ± 0.051%, respectively. The dehydrogenase activity varied significantly (p < 0.05) with the type and concentrations of metals orpesticides. The result indicates that the heavy metals and pesticides are potentially toxic to V. unquiculata root surface microorganisms. In soil, this toxicity may affect nitrogen fixation processes and by extrapolation affect crop yield

Case management of malaria in under-fives at primary health care facilities in a Tanzanian district.

OBJECTIVE: To study case management of malaria in children under 5 years of age at primary health care facilities in Kibaha district, Tanzania and to evaluate the accuracy of self-reported mothers'/guardians' information on chloroquine use in children. METHOD: A random sample of 652 mothers/guardians with sick children under 5 years of age attending 10 primary health care facilities was observed and interviewed. Blood samples for determination of chloroquine levels were taken from all children and thick smears for detection of malaria parasites were taken from the children who were prescribed chloroquine. Information on diagnoses and prescriptions was collected from recording books. RESULTS: Fever and respiratory problems were the most common complaints and accounted for 75% and 46% of the presenting conditions, respectively (some complained of both). Fifty-four per cent of the children received medication at home, most commonly antipyretics and chloroquine, 20% had been taken to another health facility and 3% to traditional healers before coming to the health facilities. There was a significantly higher use of antipyretics among home treated children compared with those taken previously to health facilities (P or= 1000 nmol/l). Of those prescribed chloroquine, 16% already had high blood concentrations of the drug. CONCLUSION: Health care services, i.e. presumptive malaria diagnosis, consultation time and procedure for physical examination need to be improved

Malaria research and its influence on anti-malarial drug policy in Malawi: a case study

BACKGROUND : In 1993, Malawi changed its first-line anti-malarial treatment for uncomplicated malaria from chloroquine to sulfadoxine-pyrimethamine (SP), and in 2007, it changed from SP to lumefantrine-artemether. The change in 1993 raised concerns about whether it had occurred timely and whether it had potentially led to early development of Plasmodium falciparum resistance to SP. This case study examined evidence from Malawi in order to assess if the policy changes were justifiable and supported by evidence. METHODS : A systematic review of documents and published evidence between 1984 and 1993, when chloroquine was the first-line drug, and 1994 and 2007, when SP was the first-line drug, was conducted herein. The review was accompanied with key informant interviews. RESULTS : A total of 1287 publications related to malaria drug policy changes in sub-Saharan Africa were identified. Using the inclusion criteria, four articles from 1984 to 1993 and eight articles from 1994 to 2007 were reviewed. Between 1984 and 1993, three studies reported on chloroquine poor efficacy prompting policy change according to WHO’s recommendation. From 1994 to 2007, four studies conducted in the early years of policy change reported a high SP efficacy of above 80%, retaining it as a first-line drug. Unpublished sentinel site studies between 2005 and 2007 showed a reduced efficacy of SP, influencing policy change to lumefantrine-artemether. The views of key informants indicate that the switch from chloroquine to SP was justified based on local evidence despite unavailability of WHO’s policy recommendations, while the switch to lumefantrine-artemether was uncomplicated as the country was following the recommendations from WHO. CONCLUSION : Ample evidence from Malawi influenced and justified the policy changes. Therefore, locally generated evidence is vital for decision making during policy change.The University of Pretoria Centre for Sustainable Malaria Control (UP CSMC)http://www.health-policy-systems.comam2016School of Health Systems and Public Health (SHSPH