Whole root preparations of three Nigerian medicinal plants, Anthocleista djalonensis, Nauclea lat... more Whole root preparations of three Nigerian medicinal plants, Anthocleista djalonensis, Nauclea latifolia and Uvaria afzalii, used traditionally in combination treatment of sexually transmitted diseases (STD), were extracted by maceration in ethanol, cold and hot water, respectively. The extracts were tested, by agar diffusion and macrobroth dilution methods, for activity against five strains of Staphylococcus aureus and two of Escherichia coli isolated from cases of STD and or urethritis. Four typed bacterial strains, S aureus ATCC 12600, Bacillus subtilis ATCC 6051, Pseudomonas aeruginosa ATCC 10145 and Escherichia coli ATCC 117755 were included as reference organisms. Ethanolic and cold-water extracts of Anthocliesta djalonensis exhibited activity against 9 and 7, respectively, of the 11 test organisms. They were bacteriostatic at minimum inhibitory concentrations (MIC) to the Gram positive strains but bactericidal to the Gram negative strains. Similar crude extracts of Uvaria afzalii showed bactericidal activity restricted to Gram positive (Staphylococcus aureus and Bacillus subtilis) strains. Nauclea latifolia extracts were bacteriostatic to both Gram positive and Gram negative strains. No test strain was susceptible to the hot water extracts of Nauclea latifolia but five and seven strains, were respectively susceptible to similar extracts of Anthocliesta djalonensis and Uvaria afzalii. Of the seven column chromatographic fractions of the ethanolic extract of Uvaria afzalii, F(ua-1) exhibited a bactericidal activity restricted to the Gram negative Escherichia coli strains, which were not susceptible to the crude extract. Fractions, F(ua-2), F(ua-3) and F(ua-4), like the crude extract, were bactericidal against the Gram positive strains only. Thus, partial purification seems to broaden the spectrum of activity and generally improve the potency of Uvaria afzalii. These results apparently justify the use of the three plants in treatment of STD.
Campylobacteriosis is the most common foodborne bacterial infection in the world. Most of the 17 ... more Campylobacteriosis is the most common foodborne bacterial infection in the world. Most of the 17 species of bacteria of the genus Campylobacter have been found in human hosts, but 95% of infections are caused by the species C. jejuni and C. coli which are transmitted principally through water and food. Understanding the mechanisms employed by these pathogens that enable them to survive in the environment and in various animal hosts will help to design strategies to limit food contamination and agents that combat the diseases caused by them. Some Campylobacter responses and adaptations to their milieux are unique to these bacteria and represent novel potential targets for therapeutic intervention.
Understanding the current status of the discovery and development of anti-Helicobacter therapies ... more Understanding the current status of the discovery and development of anti-Helicobacter therapies requires an overview of the searches for therapeutic targets performed to date. A summary is given of the very substantial body of work conducted in the quest to find Helicobacter pylori genes that could be suitable candidates for therapeutic intervention. The products of most of these genes perform metabolic functions, and others have roles in growth, cell motility and colonization. The genes identified as potential targets have been organized into three categories according to their degree of characterization. A short description and evaluation is provided of the main candidates in each category. Investigations of potential therapeutic targets have generated a wealth of information about the physiology and genetics of H. pylori, and its interactions with the host, but have yielded little by way of new therapies.
Helicobacter hepaticus is an enterohepatic bacterium associated with inflammatory bowel disease i... more Helicobacter hepaticus is an enterohepatic bacterium associated with inflammatory bowel disease in children and causes severe hepatobiliary disorders in mice. To elucidate the molecular response of H. hepaticus to bovine bile, a proteomic investigation was conducted. Bacteria were grown for 48 h in liquid media supplemented with different concentrations of bovine bile to determine its effects on bacterial growth and morphology. Protein expression profiles of bacteria grown at a bile concentration of 0.1% and in the absence of bile were obtained using two-dimensional gel electrophoresis. Gel spots with differences in intensities greater than 2-fold between both conditions were determined, and 55 differentially expressed proteins were identified using tandem mass spectrometry. Identified proteins participate in various biological functions including cell envelope biosynthesis, cell response to stress, iron homeostasis and transport, motility, primary and secondary metabolism, and virulence. Changes in the expression of H. hepaticus genes related to proteins involved in virulence and oxidative stress that were differentially expressed in the presence of bile were investigated using real-time reverse transcriptase PCR. The results indicated that the effects of bile on H. hepaticus included a strong response to oxidative stress and an expression of factors that can promote host colonization.
Helicobacter hepaticus infects the bowel and biliary tree of several animals, producing inflammat... more Helicobacter hepaticus infects the bowel and biliary tree of several animals, producing inflammation. Colonisation of mouse livers can induce hepatocellular carcinomas. The effects of H. hepaticus on the proliferation and global protein expression of human HEp-2 cells were studied by examining the changes in the protein profiles of cells exposed to the bacterium. HEp-2 cells were grown for four days under a microaerobic atmosphere or under the same conditions in co-cultures with H. hepaticus at various inoculum densities. Enlargement, distension and elongation of HEp-2 cells were observed in co-cultures with H. hepaticus. The number of live cells declined by only an order of magnitude at bacterial inocula of 10 9 cfu/ml, but were reduced to less than 10 3 cells/ml at~10 10 cfu/ml bacteria inocula. Protein expression by HEp-2 cells was investigated employing two-dimensional gel electrophoresis. In cells grown with or without bacteria, 17 differentially expressed proteins were identified by tandem mass spectrometry. These proteins participated in several biological functions including amino acid metabolism, cell growth and proliferation, stress response, protein translation and modification, etc. The onset of a catastrophic killing of HEp-2 cells at a bacterial density of 10 9 cfu/ml suggested a multimodal action for H. hepaticus infection, and the modulation of the expression of proteins involved in different biological functions showed that the presence of H. hepaticus has broad effects on the physiology of HEp-2 cells.
Campylobacter, Helicobacter and Wolinella are genera of the order Campylobacterales, belonging to... more Campylobacter, Helicobacter and Wolinella are genera of the order Campylobacterales, belonging to the class Epsilonproteobacteria. Their habitats are various niches in the gastrointestinal tract of higher animals, where they may come into contact with bile. Microorganisms in these environments require mechanisms of resistance to the surface-active amphipathic molecules with potent antimicrobial activities present in bile. This review summarizes current knowledge on the molecular responses to bile by Campylobacterales and other bacterial species that inhabit the intestinal tract and belong to the phyla Proteobacteria, Bacteriodetes, Firmicutes and Actinobacteria. To date, 125 specific genes have been implicated in bile responses, of which 10 are found in Campylobacterales. Genome database searches, analyses of protein sequence and domain similarities, and gene ontology data integration were performed to compare the responses to bile of these bacteria. The results showed that 33 proteins of bacteria belonging to the four phyla had similarities equal to or greater than 50-46% proteins of Campylobacterales. Domain architecture analyses revealed that 151 Campylobacterales proteins had similar domain composition and organization to 60 proteins known to participate in the tolerance to bile in other bacteria. The proteins CmeB, CmeF and CbrR of Campylobacter jejuni involved in bile tolerance were homologous to 42 proteins identified in the Proteobacteria, Bacteriodetes and Firmicutes. On the other hand, the proteins CiaB, CmeA, CmeC, CmeD, CmeE and FlaAs 28 also involved in the response to bile of C. jejuni, did not have homologues in other bacteria. Among the bacteria inhabiting the gastrointestinal tract, the Campylobacterales seem to have evolved some mechanisms of bile resistance similar to those of other bacteria, as well as other mechanisms that appear to be characteristic of this order. Ã Campylobacterales proteins that have both sequence and domain similarities to proteins implicated in the bile response in other bacteria. w Campylobacterales proteins that show domain but not sequence similarity to proteins implicated in the bile response in other bacteria.
The potentials of the leaves of the haemorrhage plant, Aspilia africana C. D Adams (Compositae) i... more The potentials of the leaves of the haemorrhage plant, Aspilia africana C. D Adams (Compositae) in wound care was evaluated using experimental models. A. africana, which is widespread in Africa, is used in traditional medicine to stop bleeding from wounds, clean the surfaces of sores, in the treatment of rheumatic pains, bee and scorpion stings and for removal of opacities and foreign bodies from the eyes. The present study was undertaken to evaluate the potentials for use of leaves of this plant in wound care.
Whole root preparations of three Nigerian medicinal plants, Anthocleista djalonensis, Nauclea lat... more Whole root preparations of three Nigerian medicinal plants, Anthocleista djalonensis, Nauclea latifolia and Uvaria afzalii, used traditionally in combination treatment of sexually transmitted diseases (STD), were extracted by maceration in ethanol, cold and hot water, respectively. The extracts were tested, by agar diffusion and macrobroth dilution methods, for activity against five strains of Staphylococcus aureus and two of Escherichia coli isolated from cases of STD and or urethritis. Four typed bacterial strains, S aureus ATCC 12600, Bacillus subtilis ATCC 6051, Pseudomonas aeruginosa ATCC 10145 and Escherichia coli ATCC 117755 were included as reference organisms. Ethanolic and cold-water extracts of Anthocliesta djalonensis exhibited activity against 9 and 7, respectively, of the 11 test organisms. They were bacteriostatic at minimum inhibitory concentrations (MIC) to the Gram positive strains but bactericidal to the Gram negative strains. Similar crude extracts of Uvaria afzalii showed bactericidal activity restricted to Gram positive (Staphylococcus aureus and Bacillus subtilis) strains. Nauclea latifolia extracts were bacteriostatic to both Gram positive and Gram negative strains. No test strain was susceptible to the hot water extracts of Nauclea latifolia but five and seven strains, were respectively susceptible to similar extracts of Anthocliesta djalonensis and Uvaria afzalii. Of the seven column chromatographic fractions of the ethanolic extract of Uvaria afzalii, F(ua-1) exhibited a bactericidal activity restricted to the Gram negative Escherichia coli strains, which were not susceptible to the crude extract. Fractions, F(ua-2), F(ua-3) and F(ua-4), like the crude extract, were bactericidal against the Gram positive strains only. Thus, partial purification seems to broaden the spectrum of activity and generally improve the potency of Uvaria afzalii. These results apparently justify the use of the three plants in treatment of STD.
Campylobacteriosis is the most common foodborne bacterial infection in the world. Most of the 17 ... more Campylobacteriosis is the most common foodborne bacterial infection in the world. Most of the 17 species of bacteria of the genus Campylobacter have been found in human hosts, but 95% of infections are caused by the species C. jejuni and C. coli which are transmitted principally through water and food. Understanding the mechanisms employed by these pathogens that enable them to survive in the environment and in various animal hosts will help to design strategies to limit food contamination and agents that combat the diseases caused by them. Some Campylobacter responses and adaptations to their milieux are unique to these bacteria and represent novel potential targets for therapeutic intervention.
Understanding the current status of the discovery and development of anti-Helicobacter therapies ... more Understanding the current status of the discovery and development of anti-Helicobacter therapies requires an overview of the searches for therapeutic targets performed to date. A summary is given of the very substantial body of work conducted in the quest to find Helicobacter pylori genes that could be suitable candidates for therapeutic intervention. The products of most of these genes perform metabolic functions, and others have roles in growth, cell motility and colonization. The genes identified as potential targets have been organized into three categories according to their degree of characterization. A short description and evaluation is provided of the main candidates in each category. Investigations of potential therapeutic targets have generated a wealth of information about the physiology and genetics of H. pylori, and its interactions with the host, but have yielded little by way of new therapies.
Helicobacter hepaticus is an enterohepatic bacterium associated with inflammatory bowel disease i... more Helicobacter hepaticus is an enterohepatic bacterium associated with inflammatory bowel disease in children and causes severe hepatobiliary disorders in mice. To elucidate the molecular response of H. hepaticus to bovine bile, a proteomic investigation was conducted. Bacteria were grown for 48 h in liquid media supplemented with different concentrations of bovine bile to determine its effects on bacterial growth and morphology. Protein expression profiles of bacteria grown at a bile concentration of 0.1% and in the absence of bile were obtained using two-dimensional gel electrophoresis. Gel spots with differences in intensities greater than 2-fold between both conditions were determined, and 55 differentially expressed proteins were identified using tandem mass spectrometry. Identified proteins participate in various biological functions including cell envelope biosynthesis, cell response to stress, iron homeostasis and transport, motility, primary and secondary metabolism, and virulence. Changes in the expression of H. hepaticus genes related to proteins involved in virulence and oxidative stress that were differentially expressed in the presence of bile were investigated using real-time reverse transcriptase PCR. The results indicated that the effects of bile on H. hepaticus included a strong response to oxidative stress and an expression of factors that can promote host colonization.
Helicobacter hepaticus infects the bowel and biliary tree of several animals, producing inflammat... more Helicobacter hepaticus infects the bowel and biliary tree of several animals, producing inflammation. Colonisation of mouse livers can induce hepatocellular carcinomas. The effects of H. hepaticus on the proliferation and global protein expression of human HEp-2 cells were studied by examining the changes in the protein profiles of cells exposed to the bacterium. HEp-2 cells were grown for four days under a microaerobic atmosphere or under the same conditions in co-cultures with H. hepaticus at various inoculum densities. Enlargement, distension and elongation of HEp-2 cells were observed in co-cultures with H. hepaticus. The number of live cells declined by only an order of magnitude at bacterial inocula of 10 9 cfu/ml, but were reduced to less than 10 3 cells/ml at~10 10 cfu/ml bacteria inocula. Protein expression by HEp-2 cells was investigated employing two-dimensional gel electrophoresis. In cells grown with or without bacteria, 17 differentially expressed proteins were identified by tandem mass spectrometry. These proteins participated in several biological functions including amino acid metabolism, cell growth and proliferation, stress response, protein translation and modification, etc. The onset of a catastrophic killing of HEp-2 cells at a bacterial density of 10 9 cfu/ml suggested a multimodal action for H. hepaticus infection, and the modulation of the expression of proteins involved in different biological functions showed that the presence of H. hepaticus has broad effects on the physiology of HEp-2 cells.
Campylobacter, Helicobacter and Wolinella are genera of the order Campylobacterales, belonging to... more Campylobacter, Helicobacter and Wolinella are genera of the order Campylobacterales, belonging to the class Epsilonproteobacteria. Their habitats are various niches in the gastrointestinal tract of higher animals, where they may come into contact with bile. Microorganisms in these environments require mechanisms of resistance to the surface-active amphipathic molecules with potent antimicrobial activities present in bile. This review summarizes current knowledge on the molecular responses to bile by Campylobacterales and other bacterial species that inhabit the intestinal tract and belong to the phyla Proteobacteria, Bacteriodetes, Firmicutes and Actinobacteria. To date, 125 specific genes have been implicated in bile responses, of which 10 are found in Campylobacterales. Genome database searches, analyses of protein sequence and domain similarities, and gene ontology data integration were performed to compare the responses to bile of these bacteria. The results showed that 33 proteins of bacteria belonging to the four phyla had similarities equal to or greater than 50-46% proteins of Campylobacterales. Domain architecture analyses revealed that 151 Campylobacterales proteins had similar domain composition and organization to 60 proteins known to participate in the tolerance to bile in other bacteria. The proteins CmeB, CmeF and CbrR of Campylobacter jejuni involved in bile tolerance were homologous to 42 proteins identified in the Proteobacteria, Bacteriodetes and Firmicutes. On the other hand, the proteins CiaB, CmeA, CmeC, CmeD, CmeE and FlaAs 28 also involved in the response to bile of C. jejuni, did not have homologues in other bacteria. Among the bacteria inhabiting the gastrointestinal tract, the Campylobacterales seem to have evolved some mechanisms of bile resistance similar to those of other bacteria, as well as other mechanisms that appear to be characteristic of this order. Ã Campylobacterales proteins that have both sequence and domain similarities to proteins implicated in the bile response in other bacteria. w Campylobacterales proteins that show domain but not sequence similarity to proteins implicated in the bile response in other bacteria.
The potentials of the leaves of the haemorrhage plant, Aspilia africana C. D Adams (Compositae) i... more The potentials of the leaves of the haemorrhage plant, Aspilia africana C. D Adams (Compositae) in wound care was evaluated using experimental models. A. africana, which is widespread in Africa, is used in traditional medicine to stop bleeding from wounds, clean the surfaces of sores, in the treatment of rheumatic pains, bee and scorpion stings and for removal of opacities and foreign bodies from the eyes. The present study was undertaken to evaluate the potentials for use of leaves of this plant in wound care.
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