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Background: Unlike plant phytochemicals, little has been done to explore the metabolites from phyllosphere bacterial flora, some of which enabled them to survive interspecific competition through amensalism. This study evaluated the antimicrobial activity of metabolites from Phyllospheric Bacteria (PB) isolated from Funtumia elastica (FE), against selected bacterial and fungal pathogens. Phenotypic and molecular methods were used to identify the isolated phyllo-microbiota. Methods: The PB were aseptically isolated by sonication. Their metabolites were obtained from the fresh overnight culture of the organisms. The cell-free supernatants containing the metabolites were used for antimicrobial assays against the pathogens. The DNA of the bacterial isolates were isolated using a NIMR-BIOTECH DNA extraction kit, while their 16S rRNA was amplified with the primer: 799F 5'-AACACGGATTA GATACC-3', 1193R 5'- ACGTCATCCCCACCTTCC-3', using SolisFast* Master Mix, (Solis Biodyne-Estonia). The BLAST of the sequence was done from the NCBI Genbank. The PB strains identified were submitted to NCBI and accession numbers were assigned to them. Results: The phyllosphere of FE yielded 21 bacterial isolates: 7 Gram-positives and 14 Gram-negatives. The metabolites from these isolates showed varying degrees of bioactivity against Staphylococcus aureus (ATCC29213), Escherichia coli (ATCC 25922) Klebsiella pneumoniae (ATCC 35659); Trychophyton rubrum, Candida albicans and Microsporum canis. Fifteen bioactive isolates sequenced yielded four genera, Enterobacter (E. hormaechei 98.44%), Bacillus (B. cereus 100%), Pontoea (P. dispersa 99.72%), Staphylococcus (S. arlettae 99.72%). Conclusion: Bacteria from FE phyllosphere, produced metabolites antagonistic (cidal) to some human pathogens. This has great potential for possible drug discovery. [ABSTRACT FROM AUTHOR]

Human enteroviruses are the major cause of aseptic meningitis and are resistant to all known antibiotics and chemotherapeutic agents. Methanolic extracts of Eucalyptus camaldulensis and Eucalyptus torelliana were tested on human enteroviruses: Poliovirus type I, Coxsackievirus B and Echovirus 6. The virucidal tests showed that the crude extracts were active on the test viruses: poliovirus type 1, coxsackievirus B and echovirus 6 giving a neutralization index of one log and above. The cytotoxicity assay of the crude extracts to L20B (a genetically engineered mouse cell line) and human rhabdomyo sarcoma (RD) cells showed that the extract of E. torelliana was more toxic than the extract of E. camaldulensis. The antiviral study showed that the extract of E. torelliana was more active than that of E. camaldulensis. [ABSTRACT FROM AUTHOR]

Context: Eucalyptus camaldulensis Dehnh. (Myrtaceae) and Eucalyptus torelliana F. Muell are used in Nigerian traditional medicine for the treatment of cough associated with tuberculosis (TB) and other respiratory infections. Objective: Hexane, chloroform, methanol extracts, and isolated compounds of E. camaldulensis and E. torelliana were screened for activity against Mycobacterium tuberculosis H37Rv (MtbH37Rv) to authenticate the traditional use of these plants. Materials and methods: The microplate alamar blue assay (MABA) method was used to investigate the anti- M. tuberculosis activities. Bioassay-guided fractionation of the hexane extract of E. torelliana leaf was performed, and isolated compounds were characterized by MS, 1D- and 2D-NMR. Results: The extracts inhibited the growth of MtbH37Rv [minimum inhibitory concentration (MIC) 4-64 µg/mL]. Spectroscopic characterization led to the identification of two compounds, hydroxymyristic acid methylester ( 1) and a substituted pyrenyl ester, a sterol ( 2). Compounds 1 and 2 had MIC of 49.45 and 46.99 µg/mL; IC50 >100 and 38.21 µg/mL; selectivity index (SI) >2.02 and 0.81, respectively, and a minimum bactericidal concentration (MBC) of 62.50 µg/mL. Discussion and conclusions: The anti-TB activities of these plants on M. tuberculosis H37Rv support their use in traditional medicine for the treatment of coughs associated with TB and reveals the presence of anti- Mtb active compounds in the plants. These findings not only demonstrate a new potential area of therapeutic value of E. camaldulensis and E. torelliana, but also illustrate the role of esters as anti- Mtb active principles in ethnobotanical preparations and as lead compounds in the development of new and effective anti- Mtb drugs. [ABSTRACT FROM AUTHOR]

Helicobacter pylori is the primary etiologic agent of peptic ulcer, duodenal ulcer, chronic gastritis, gastric adenocarcinoma and related gastroduodenal disorders. Current triple therapy, including antibiotics and proton-pump inhibitors, has been successful; however, adverse events, non-patient compliance and consequent relapse of Helicobacter pylori infections are common. Crude methanol extracts of Eucalyptus grandis Hill ex. Maiden (Myrtaceae) stem bark were screened against a standard strain ATCC 43504 and ten clinical strains of H. pylori using the agar diffusion method on Mueller-Hinton agar supplemented with defibrinated horse blood and grown in a microaerophilic incubator. All the strains except UCH 97002 and UCH 98020 were inhibited by the extract to varying degrees. The minimum inhibitory concentration (MIC) against the susceptible strains tested ranged from 0.39 and 1.56 μg/mL. The urease activity of the three H. pylori strains tested decreased with increasing concentrations of the extract. The greatest inhibition of urease activity was observed in clinical strain UCH 97009. In addition, methanol extracts of the E. grandis enhanced cell aggregation of seven of the H. pylori strains leading to a decrease in the cell surface hydrophobicity. The salt aggregation test titer decreased from >3 to <1.5 for five of the strains and to <3 for two of the strains. Phytochemical screening of the plant revealed the presence of tannins, essential oils and saponins, while alkaloids were not detected. The anti- Helicobacter pylori activity observed in this study correlates well with the traditional use of this plant in Nigeria. [ABSTRACT FROM AUTHOR]

Previous investigations demonstrated that a standardized extract of ginger rhizome inhibited the growth of Helicobacter pylori in vitro with a minimum inhibitory concentration in the range 0.78 to 12.5 μg/mL. In the present work, the extract was tested in a rodent model of H. pylori-induced disease, the Mongolian gerbil, to examine the effects of the extract on both prevention and eradication of infection. The extract was administered to Mongolian gerbils at a daily dose of 100 mg/kg body weight in rations either 3 weeks prior to infection or 6 weeks post-infection. Treatment with the standardized ginger extract reduced H. pylori load as compared with controls and significantly ( P<0.05) reduced both acute and chronic muscosal and submucosal inflammation, cryptitis, as well as epithelial cell degeneration and erosion induced by H. pylori. Importantly, the extract did not increase morbidity or mortality. Further investigations of the mechanism demonstrated that the ginger extract inhibited the activity of cyclooxygenase-2, with 50% inhibitory concentration (IC50) of 8.5 μg/mL in vitro, inhibited the nuclear factor-κβ transcriptional response in kBZ Jurkat cells (human T lymphocytes) with an IC50 of 24.6 μg/mL, and significantly inhibited the release of interleukin (IL)-1β, IL-6, IL-8, and tumor necrosis factor-α from lipopolysaccharide-stimulated human peripheral blood mononuclear cells with IC50 values of 3.89, 7.7, 8.5, and 8.37 μg/mL, respectively. These results suggest ginger extracts may be useful for development as agents to reduce H. pylori-induced inflammation and as for gastric cancer chemoprevention. [ABSTRACT FROM AUTHOR]

Previous investigations demonstrated that a standardized extract of ginger rhizome inhibited the growth of Helicobacter pylori in vitro with a minimum inhibitory concentration in the range 0.78 to 12.5 mug/mL. In the present work, the extract was tested in a rodent model of H. pylori-induced disease, the Mongolian gerbil, to examine the effects of the extract on both prevention and eradication of infection. The extract was administered to Mongolian gerbils at a daily dose of 100 mg/kg body weight in rations either 3 weeks prior to infection or 6 weeks post-infection. Treatment with the standardized ginger extract reduced H. pylori load as compared with controls and significantly (P<0.05) reduced both acute and chronic muscosal and submucosal inflammation, cryptitis, as well as epithelial cell degeneration and erosion induced by H. pylori. Importantly, the extract did not increase morbidity or mortality. Further investigations of the mechanism demonstrated that the ginger extract inhibited the activity of cyclooxygenase-2, with 50% inhibitory concentration (IC(50)) of 8.5 mug/mL in vitro, inhibited the nuclear factor-kappaB transcriptional response in kBZ Jurkat cells (human T lymphocytes) with an IC(50) of 24.6 mug/mL, and significantly inhibited the release of interleukin (IL)-1beta, IL-6, IL-8, and tumor necrosis factor-alpha from lipopolysaccharide-stimulated human peripheral blood mononuclear cells with IC(50) values of 3.89, 7.7, 8.5, and 8.37 mug/mL, respectively. These results suggest ginger extracts may be useful for development as agents to reduce H. pylori-induced inflammation and as for gastric cancer chemoprevention.

Objectives: In this study, extended-spectrum beta-lactamases (ESBLs) were characterized from 30 selected multidrug-resistant Klebsiella pneumoniae strains isolated from patients with community-acquired urinary tract infections from Southwest Nigeria., Methods: The beta-lactamases were phenotypically characterized using isoelectric focusing, genotypically characterized using PCR assays and hybridization of the PCR products. Two of the bla(CTX-M) genes were completely sequenced. The location of the CTX-M-type genes was determined using transformation, DNA-DNA hybridization, PCR assays and hybridization of the PCR products from the Escherichia coli transformants., Results: All 30 isolates produced at least one beta-lactamase. Seventeen of the isolates were resistant to cefotaxime, and had > or =100-fold reduction in susceptibility with cefotaxime plus clavulanic acid (4 mg/L), indicating the presence of an ESBL. The 17 isolates were shown to have bla(CTX-M) genes that were associated with large plasmids (> or =58 kb), which also carried a tetracycline resistance gene, tet(A), and various aminoglycoside resistance genes. Two CTX-M-type genes were sequenced and had amino acid sequences indistinguishable from previously sequenced CTX-M-15 beta-lactamases. The ISEcp1 element was located upstream of bla(CTX-M-15) in the same position as previously described. In addition, 23 of the isolates produced TEM beta-lactamases, 27 produced SHV beta-lactamases and four produced AmpC beta-lactamases., Conclusions: Thirty K. pneumoniae produced multiple beta-lactamases, with 57% producing CTX-M enzymes. This is the first characterization of CTX-M-15-positive K. pneumoniae in Western Africa.