Antibacterial and Antioxidant Activity of Different Extracts of Some Wild Medicinal Mushrooms from Nigeria.

This study assessed the antioxidant properties and antibacterial effects of hot water, cold water, and ethanol extracts of Agaricomycetes mushrooms Trametes betulina, Pleurotus ostreatus, Agaricus bisporus var. albidus, and A. bisporus var. avellaneus against Pseudomonas aeruginosa, Escherichia coli, and Klebsiella pneumoniae. The mushroom extracts were assessed for total phenolic content as well as 2,2-diphenyl-1-picrylhydrazyl (DPPH) and hydrogen peroxide scavenging activities. The multiantibiotic resistance index (MARI) of the bacterial isolates was assessed and the antimicrobial activity of the mushroom extracts was assayed with the agar disc diffusion method. The agar well diffusion assay was performed to determine their minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The test bacteria were multidrug resistant against antibiotics, with P. aeruginosa having the highest MARI followed by K. pneumoniae and E. coli. Cold water extracts showed a better antibacterial effect compared to the others and a concentration/effect correlation was observed (from 5 to 500 mg/mL). Ethanol extracts from P. ostreatus and hot water extracts from T. betulina were the most effective in inhibiting and lysing E. coli and K. pneumoniae, respectively, at a MIC and MBC of 3.90 mg/mL. The tested extracts, especially P. ostreatus extract, showed high DPPH and hydrogen peroxide scavenging potential as well as high total phenolic content compared to standard antioxidants. This study showed that the screened agaricomycetous mushrooms possess antibacterial activity against bacterial pathogens as well as antioxidant activity due to their high phenolic content.

Prevalence, pattern, and determinants of placental malaria in a population of southeastern Nigerian parturients.

BACKGROUND: Placental malaria is a complication of malaria in pregnancy and is associated with adverse outcomes. Its burden is highest in Sub-Saharan Africa, but despite this, data based on histological analysis are scarce from this region. METHODS: Questionnaires administered by the researchers were used to obtain information from parturients at a university teaching hospital in southeastern Nigeria between April and November 2010. Maternal blood and placental blood were collected for analysis. Placental blocks were taken for histological analysis. Statistical analyses were done using SPSS v. 17. RESULTS: Three hundred and sixty-five placentas were analyzed, out of which 254 showed histological evidence of malaria parasitization, giving a prevalence of 69.6%. Of the 254 placentas, 23 (9.0%) showed active infection and 196 (77.2%) showed active-on-past infection, while 35 (13.8%) showed past infection. Rural residence, hemoglobin genotype AA, not receiving intermittent preventive treatment in pregnancy (IPTp), and not sleeping under insecticide-treated bed nets (ITN) were significantly associated with placental malaria. Placental parasite density was inversely related to parity. CONCLUSIONS: This study showed that the prevalence of placental malaria in southeastern Nigeria is high, and demonstrated that the mean parasite density was inversely related to parity. Significant factors associated with placental malaria were also identified. Appreciation of these significant factors will assist program managers in implementing the strategies for the prevention of malaria in pregnancy.