Behailu Merdekios | University of Antwerp (original) (raw)

Papers by Behailu Merdekios

Research paper thumbnail of Causes and trends of adult mortality in southern Ethiopia: an eight-year follow up database study

BMC Infectious Diseases, Jan 18, 2023

Background Broad and specific causes of adult mortalities are often neglected indicators of wellb... more Background Broad and specific causes of adult mortalities are often neglected indicators of wellbeing in lowincome countries like Ethiopia due to lack of strong vital statistics. Thus, this database study aimed to assess the causes of adult mortality using demographic surveillance data. Methods An 8-year (12 September 2009-11 September 2017) surveillance data from the Arba Minch Health and Demographic Surveillance Site was used for this study. Verbal autopsy methods and ICD codes were used to identify the causes of the adult deaths. The collected data were entered to the database by data clerks. We used Microsoft Excel and STATA version 16 software for data cleaning and analysis. Chi-squared test was used to see the significances of the trend analyses. Result From the 943 adult deaths from 2009 to 2017 in the Health and Demographic Surveillance Site in southern Ethiopia, more than half of them were females. The specific leading cause of death in the adults were tuberculosis (16.8%), malaria (9.7%), and intestinal infectious diseases (9.6%). Communicable diseases (49.2%, 95% C.I 45.7, 52.7) accounted for about half of the deaths followed by non-communicable diseases (35%, 95% C.I 31.7, 38.4) where both categories showed an increasing trend. Conclusion Although pieces of evidences are showing the shift from communicable diseases to non-communicable diseases as the major causes of adult death in developing countries, this study showed that communicable diseases are still the major causes of adult deaths. Efforts and emphasis should be given to control infectious diseases such as tuberculosis and malaria.

Research paper thumbnail of In vitro Antibacterial Activity and Phytochemical Analysis of Nicotiana tabacum L. Extracted in Different Organic Solvents

The Open Microbiology Journal, Dec 29, 2017

Background: Controlling infectious disease using medicinal plants is the oldest healthcare known ... more Background: Controlling infectious disease using medicinal plants is the oldest healthcare known to mankind. Regardless of the enormous advances observed in modern medicine, medicinal plants are still playing vital roles. However, only a small proportion of medicinal plants are examined for bioactive compounds which may vary in different factors. This study aimed to evaluate phytochemical constituent and antimicrobial activities of Nicotiana tabacum L. extracted by different solvents against three set of bacteria. Methods: Nicotiana tabacum L. was collected from the Western Ethiopia and extracted in seven organic solvents. An in-vitro anti-bacterial activity of plant extracts was carried out by agar well diffusion assay against microbial type culture collection of human pathogens, clinical bacterial isolates, and biofilm forming bacteria. Gas Chromatographic and Mass Spectroscopic (GC-MS) analysis was used to determine the phytochemical constituents. Results: Antimicrobial activities of plant extract vary by extraction solvents; and ethyl acetate based extracts showed better antimicrobial activities. Of the experimental organisms, biofilm forming uropathogens were the most sensitive while clinical isolates were quite resistant. Analysis of the active ethyl acetate extract by GC-MS evinced a mixture of five volatile compounds; and Pyridine, 3-(1methyl-2-pyrrolidinyl)-, (S) was the major compound detected. The overall results of the present study revealed that N. tabacum L extract has high antimicrobial activities against biofilm forming uropathogens. Conclusion: High antimicrobial activity was observed in ethyl acetate extract of N. tabacum against the biofilm forming bacteria whereas the clinically isolated bacteria were the most resistant group. The antibacterial property demonstrated could be due to Pyridine, 3-(1methyl-2-pyrrolidinyl)-(S) with a broad spectrum of activity.

Research paper thumbnail of Salivary and Serum Antibody Response Against Neisseria meningitidis After Vaccination With Conjugate Polysaccharide Vaccines in Ethiopian Volunteers

Scandinavian Journal of Immunology, 2016

Meningococcal conjugate vaccines induce serum antibodies crucial for protection against invasive ... more Meningococcal conjugate vaccines induce serum antibodies crucial for protection against invasive disease. Salivary antibodies are believed to be important for hindering meningococcal acquisition and/or clearance of established carriage. In this study, we measured salivary IgA and IgG antibodies induced by vaccination with a monovalent serogroup A conjugate vaccine or a tetravalent A, C, W and Y conjugate vaccine, in comparison with antibody levels in serum. Saliva and serum samples from Ethiopian volunteers (1-29 years) collected before and eight times on a weekly basis after receiving the serogroup A conjugate vaccine, the tetravalent serogroup A, C, W and Y conjugate vaccine, or no vaccine (control group), were analysed using a multiplex microsphere immunoassay for antibody detection. Serogroup-specific IgG antibody levels in saliva increased significantly after vaccination with both vaccines. The monovalent serogroup A vaccine also induced an increase in salivary IgA antibodies. A strong correlation between serogroup-specific IgG antibodies in saliva and serum, and a somewhat lower correlation for IgA, was observed for all serogroups. There was also a strong correlation between specific secretory IgA and IgA antibodies in saliva for all serogroups. Meningococcal conjugate vaccines are able to elicit salivary antibodies against serogroup A, C, W and Y correlating with antibody levels in serum. The strong correlation between saliva and serum antibody levels indicates that saliva may be used as a surrogate of systemic antibody responses.

Research paper thumbnail of Additional file 4 of An integrative approach to identify sand fly vectors of leishmaniasis in Ethiopia by morphological and molecular techniques

Additional file 4: Table S3 Interspecies K2P distances of cox1 gene of Phlebotomus sand flies of ... more Additional file 4: Table S3 Interspecies K2P distances of cox1 gene of Phlebotomus sand flies of the subgenus Adlerius.

Research paper thumbnail of Additional file 2 of An integrative approach to identify sand fly vectors of leishmaniasis in Ethiopia by morphological and molecular techniques

Additional file 2: Table S2. Interspecies K2P distances of cox1 and nad4 genes of Ethiopian sand ... more Additional file 2: Table S2. Interspecies K2P distances of cox1 and nad4 genes of Ethiopian sand flies. The lower left quadrant presents the K2P distances (SD) of the cox1 gene, the upper right quadrant of the nad4 gene. The nad4 gene of P. duboscqi specimens was not included in the analysisa.

Research paper thumbnail of Additional file 4 of An integrative approach to identify sand fly vectors of leishmaniasis in Ethiopia by morphological and molecular techniques

Additional file 4: Table S3 Interspecies K2P distances of cox1 gene of Phlebotomus sand flies of ... more Additional file 4: Table S3 Interspecies K2P distances of cox1 gene of Phlebotomus sand flies of the subgenus Adlerius.

Research paper thumbnail of An in vitro antibacterial activity and phytochemical analysis of Nicotiana tabacum L. sourced from the Western Ethiopia

The Open Microbiology Journal, 2017

Background: Controlling infectious disease using medicinal plants is the oldest healthcare known ... more Background: Controlling infectious disease using medicinal plants is the oldest healthcare known to mankind. Regardless of the enormous advances observed in modern medicine, medicinal plants are still playing vital roles. However, only a small proportion of medicinal plants are examined for bioactive compounds which may vary in different factors. This study aimed to evaluate phytochemical constituent and antimicrobial activities of Nicotiana tabacum L. extracted by different solvents against three set of bacteria. Methods: Nicotiana tabacum L. was collected from the Western Ethiopia and extracted in seven organic solvents. An in-vitro anti-bacterial activity of plant extracts was carried out by agar well diffusion assay against microbial type culture collection of human pathogens, clinical bacterial isolates, and biofilm forming bacteria. Gas Chromatographic and Mass Spectroscopic (GC-MS) analysis was used to determine the phytochemical constituents. Results: Antimicrobial activities of plant extract vary by extraction solvents; and ethyl acetate based extracts showed better antimicrobial activities. Of the experimental organisms, biofilm forming uropathogens were the most sensitive while clinical isolates were quite resistant. Analysis of the active ethyl acetate extract by GC-MS evinced a mixture of five volatile compounds; and Pyridine, 3-(1methyl-2-pyrrolidinyl)-, (S) was the major compound detected. The overall results of the present study revealed that N. tabacum L extract has high antimicrobial activities against biofilm forming uropathogens. Conclusion: High antimicrobial activity was observed in ethyl acetate extract of N. tabacum against the biofilm forming bacteria whereas the clinically isolated bacteria were the most resistant group. The antibacterial property demonstrated could be due to Pyridine, 3-(1methyl-2-pyrrolidinyl)-(S) with a broad spectrum of activity.

Research paper thumbnail of Additional file 2 of An integrative approach to identify sand fly vectors of leishmaniasis in Ethiopia by morphological and molecular techniques

Additional file 2: Table S2. Interspecies K2P distances of cox1 and nad4 genes of Ethiopian sand ... more Additional file 2: Table S2. Interspecies K2P distances of cox1 and nad4 genes of Ethiopian sand flies. The lower left quadrant presents the K2P distances (SD) of the cox1 gene, the upper right quadrant of the nad4 gene. The nad4 gene of P. duboscqi specimens was not included in the analysisa.

Research paper thumbnail of An in vitro antibacterial activity and phytochemical analysis of Nicotiana tabacum L. sourced from the Western Ethiopia

The Open Microbiology Journal, 2017

Background: Controlling infectious disease using medicinal plants is the oldest healthcare known ... more Background: Controlling infectious disease using medicinal plants is the oldest healthcare known to mankind. Regardless of the enormous advances observed in modern medicine, medicinal plants are still playing vital roles. However, only a small proportion of medicinal plants are examined for bioactive compounds which may vary in different factors. This study aimed to evaluate phytochemical constituent and antimicrobial activities of Nicotiana tabacum L. extracted by different solvents against three set of bacteria. Methods: Nicotiana tabacum L. was collected from the Western Ethiopia and extracted in seven organic solvents. An in-vitro anti-bacterial activity of plant extracts was carried out by agar well diffusion assay against microbial type culture collection of human pathogens, clinical bacterial isolates, and biofilm forming bacteria. Gas Chromatographic and Mass Spectroscopic (GC-MS) analysis was used to determine the phytochemical constituents. Results: Antimicrobial activities of plant extract vary by extraction solvents; and ethyl acetate based extracts showed better antimicrobial activities. Of the experimental organisms, biofilm forming uropathogens were the most sensitive while clinical isolates were quite resistant. Analysis of the active ethyl acetate extract by GC-MS evinced a mixture of five volatile compounds; and Pyridine, 3-(1methyl-2-pyrrolidinyl)-, (S) was the major compound detected. The overall results of the present study revealed that N. tabacum L extract has high antimicrobial activities against biofilm forming uropathogens. Conclusion: High antimicrobial activity was observed in ethyl acetate extract of N. tabacum against the biofilm forming bacteria whereas the clinically isolated bacteria were the most resistant group. The antibacterial property demonstrated could be due to Pyridine, 3-(1methyl-2-pyrrolidinyl)-(S) with a broad spectrum of activity.

Research paper thumbnail of An in vivo efficacy validation and immune-modulatory potential of Streptomyces sp

Journal of Coastal Life Medicine, 2015

An in vivo efficacy validation and immune-modulatory potential of Streptomyces sp.

Research paper thumbnail of An in vivo efficacy validation and immune-modulatory potential of Streptomyces sp

Journal of Coastal Life Medicine, 2015

An in vivo efficacy validation and immune-modulatory potential of Streptomyces sp.

Research paper thumbnail of An In Vitro Antibacterial and Cytotoxic Potentials of Bioactive Metabolites Extracted from Padina tetrastromatica

Translational Biomedicine, 2016

Marine brown algae, Padina tetrastromatica was extracted using diverse organic solvents of increa... more Marine brown algae, Padina tetrastromatica was extracted using diverse organic solvents of increasing polarity such as diethyl ether, chloroform, acetone, dichloromethane: methanol and methanol. The obtained extracts were evaluated for antibacterial and brine shrimp cytotoxicity assays. It was found that methanolic extract of P. tetrastromatica exhibited the broadest and highest range of antibacterial activity. In cytotoxic activity, the methanolic extract of P. tetrastromatica showed significant activity (LD 50 =354.4 µg/mL). Based on the present findings, it could be inferred that the bioassay guided purification and fractionation of crude methanolic extract of P. tetrastromatica may bring forth potent novel antibiotic and anticancer leads.

Research paper thumbnail of An In Vitro Antibacterial and Cytotoxic Potentials of Bioactive Metabolites Extracted from Padina tetrastromatica

Translational Biomedicine, 2016

Marine brown algae, Padina tetrastromatica was extracted using diverse organic solvents of increa... more Marine brown algae, Padina tetrastromatica was extracted using diverse organic solvents of increasing polarity such as diethyl ether, chloroform, acetone, dichloromethane: methanol and methanol. The obtained extracts were evaluated for antibacterial and brine shrimp cytotoxicity assays. It was found that methanolic extract of P. tetrastromatica exhibited the broadest and highest range of antibacterial activity. In cytotoxic activity, the methanolic extract of P. tetrastromatica showed significant activity (LD 50 =354.4 µg/mL). Based on the present findings, it could be inferred that the bioassay guided purification and fractionation of crude methanolic extract of P. tetrastromatica may bring forth potent novel antibiotic and anticancer leads.

Research paper thumbnail of Evaluating the Antibacterial Potential of Streptomyces sp

Translational Biomedicine, 2015

Background and Objectives: Marine bacteria are recognized as an untapped resource of bioactive me... more Background and Objectives: Marine bacteria are recognized as an untapped resource of bioactive metabolites of diverse structure and functions. The present research is focused on the screening of the antagonistic potential of bacteria isolated from marine sponge against human and shrimp pathogens. Methods and Findings: In this study, a total of 51 strains of bacteria isolated from five species of marine sponges sourced from the Vizhinjam littoral (Indian Ocean) were screened for possible antagonistic activity against human and shrimp pathogens. Of the 51 bacterial isolates, twelve strains isolated from marine sponges, S.officinalis and D. nigra showed different ranges of activity. The results of agar-well diffusion assay showed that, out of the twelve strains, MAPS 15 strain showed the highest activity which subdued the growth of all the tested 20 bacterial pathogens. The molecular characterization based on partial 16S rRNA sequence revealed that the active isolate MAPS 15 was Streptomyces sp. Conclusion: This study serves as a basis for further research on the possibility of utilizing Streptomyces sp. for the development of human and veterinary grade antibiotics.

Research paper thumbnail of An in vitro antibacterial and anticandidal activity of Sonneratia alba (J. Smith)

Research paper thumbnail of In vitro antibacterial activity of medicinal plant extracts against Escherichia coli strains from human clinical specimens and interactions with antimicrobial drugs

Natural Product Research, 2012

Objective: Various diseases are caused by different pathogenic microorganisms. Antibiotics are be... more Objective: Various diseases are caused by different pathogenic microorganisms. Antibiotics are being used for treatment of these infectious diseases, yet unpredictable utilization of it leads towards antibacterial resistance. It is required to discover better approaches to battle against antibacterial resistance. Therefore, the study aimed to detect antibacterial sensitivity of ethanol extracts of Curcuma longa (turmeric), Cinnamomumzeylanicum (clove) and Syzygiumaromaticum (cinnamon) against Syaphylococcus aureus and E coli. Methods: Prior to sensitivity testing, ethanol oils were extracted by an electric blender and each of the bacteria strains were cultured onto blood agar plate. Antibacterial activity was tested by agar well diffusion method where three different concentrations (50 μl, 75 μl and 100 μl) of selected plants extract were used so far as to measure the inhibition zone. Inhibition zone of the ethanol extract of these plants were calculated where three were found to be sensitive against Syaphylococcus aureus and E coli. Results: Greater inhibition zone 14.5 mm, 18.25 mm, 21.5 mm at100 μl against Syaphylococcus aureus in case of cinnamon whereas the least inhibition zone was showed by turmeric and it was 9.00 mm, 11.00 mm, and 12.75 mm at 100 μl extract against E. coli. Conclusion: Overall, all the ethanol extracts were found to effective against these two bacteria but cinnamon can be used as more effective antibacterial agent in both human and veterinary field after the toxicological test.

Research paper thumbnail of Additional file 3 of An integrative approach to identify sand fly vectors of leishmaniasis in Ethiopia by morphological and molecular techniques

Additional file 3: Figure S1. Comparison of MALDI-TOF MS protein profiles of Ethiopian Adlerius s... more Additional file 3: Figure S1. Comparison of MALDI-TOF MS protein profiles of Ethiopian Adlerius sp. with five other species of the subgenus Adlerius. Zoomed mass range of 4 to 15 kDa is depicted.

Research paper thumbnail of Additional file 1 of An integrative approach to identify sand fly vectors of leishmaniasis in Ethiopia by morphological and molecular techniques

Additional file 1: Table S1. Intraspecies K2P distances of cox1 and nad4 genes of Ethiopian sand ... more Additional file 1: Table S1. Intraspecies K2P distances of cox1 and nad4 genes of Ethiopian sand flies. Abbreviations: K2P, Kimura 2-parameter model; SD, standard deviation.

Research paper thumbnail of Additional file 3 of High-resolution habitat suitability model for Phlebotomus pedifer, the vector of cutaneous leishmaniasis in southwestern Ethiopia

Additional file 3: Figure S2. Dependence of the predicted suitability on the six least contributi... more Additional file 3: Figure S2. Dependence of the predicted suitability on the six least contributing variables. The curves show how the prediction changes as each environmental variable is varied, keeping all other environmental variables at their average sample value. The cloglog value provides an estimate between 0 and 1 of probability of presence. Abbreviations: EVIdry, enhanced vegetation index in the dry season; Pdry, precipitation in the driest months; Pmean, mean precipitation; Cliffs, ordinal categorical values indicating cliffs between 20–40% and above 40%; EVIwet, enhanced vegetation index in the wet season.

Research paper thumbnail of Additional file 2 of High-resolution habitat suitability model for Phlebotomus pedifer, the vector of cutaneous leishmaniasis in southwestern Ethiopia

Additional file 2: Table S1. Percent variable contribution and jackknife estimates indicating the... more Additional file 2: Table S1. Percent variable contribution and jackknife estimates indicating the most important variables for the model. Abbreviations: SD, standard deviation; Tmean, mean temperature; Pseas, precipitation seasonality; EVIdry, enhanced vegetation index in the dry season; Pdry, precipitation in the driest months; Pmean, mean precipitation; Cliffs, ordinal categorical values indicating cliffs between 20–40% and above 40%; EVIwet, enhanced vegetation index in the wet season.

Research paper thumbnail of Causes and trends of adult mortality in southern Ethiopia: an eight-year follow up database study

BMC Infectious Diseases, Jan 18, 2023

Background Broad and specific causes of adult mortalities are often neglected indicators of wellb... more Background Broad and specific causes of adult mortalities are often neglected indicators of wellbeing in lowincome countries like Ethiopia due to lack of strong vital statistics. Thus, this database study aimed to assess the causes of adult mortality using demographic surveillance data. Methods An 8-year (12 September 2009-11 September 2017) surveillance data from the Arba Minch Health and Demographic Surveillance Site was used for this study. Verbal autopsy methods and ICD codes were used to identify the causes of the adult deaths. The collected data were entered to the database by data clerks. We used Microsoft Excel and STATA version 16 software for data cleaning and analysis. Chi-squared test was used to see the significances of the trend analyses. Result From the 943 adult deaths from 2009 to 2017 in the Health and Demographic Surveillance Site in southern Ethiopia, more than half of them were females. The specific leading cause of death in the adults were tuberculosis (16.8%), malaria (9.7%), and intestinal infectious diseases (9.6%). Communicable diseases (49.2%, 95% C.I 45.7, 52.7) accounted for about half of the deaths followed by non-communicable diseases (35%, 95% C.I 31.7, 38.4) where both categories showed an increasing trend. Conclusion Although pieces of evidences are showing the shift from communicable diseases to non-communicable diseases as the major causes of adult death in developing countries, this study showed that communicable diseases are still the major causes of adult deaths. Efforts and emphasis should be given to control infectious diseases such as tuberculosis and malaria.

Research paper thumbnail of In vitro Antibacterial Activity and Phytochemical Analysis of Nicotiana tabacum L. Extracted in Different Organic Solvents

The Open Microbiology Journal, Dec 29, 2017

Background: Controlling infectious disease using medicinal plants is the oldest healthcare known ... more Background: Controlling infectious disease using medicinal plants is the oldest healthcare known to mankind. Regardless of the enormous advances observed in modern medicine, medicinal plants are still playing vital roles. However, only a small proportion of medicinal plants are examined for bioactive compounds which may vary in different factors. This study aimed to evaluate phytochemical constituent and antimicrobial activities of Nicotiana tabacum L. extracted by different solvents against three set of bacteria. Methods: Nicotiana tabacum L. was collected from the Western Ethiopia and extracted in seven organic solvents. An in-vitro anti-bacterial activity of plant extracts was carried out by agar well diffusion assay against microbial type culture collection of human pathogens, clinical bacterial isolates, and biofilm forming bacteria. Gas Chromatographic and Mass Spectroscopic (GC-MS) analysis was used to determine the phytochemical constituents. Results: Antimicrobial activities of plant extract vary by extraction solvents; and ethyl acetate based extracts showed better antimicrobial activities. Of the experimental organisms, biofilm forming uropathogens were the most sensitive while clinical isolates were quite resistant. Analysis of the active ethyl acetate extract by GC-MS evinced a mixture of five volatile compounds; and Pyridine, 3-(1methyl-2-pyrrolidinyl)-, (S) was the major compound detected. The overall results of the present study revealed that N. tabacum L extract has high antimicrobial activities against biofilm forming uropathogens. Conclusion: High antimicrobial activity was observed in ethyl acetate extract of N. tabacum against the biofilm forming bacteria whereas the clinically isolated bacteria were the most resistant group. The antibacterial property demonstrated could be due to Pyridine, 3-(1methyl-2-pyrrolidinyl)-(S) with a broad spectrum of activity.

Research paper thumbnail of Salivary and Serum Antibody Response Against Neisseria meningitidis After Vaccination With Conjugate Polysaccharide Vaccines in Ethiopian Volunteers

Scandinavian Journal of Immunology, 2016

Meningococcal conjugate vaccines induce serum antibodies crucial for protection against invasive ... more Meningococcal conjugate vaccines induce serum antibodies crucial for protection against invasive disease. Salivary antibodies are believed to be important for hindering meningococcal acquisition and/or clearance of established carriage. In this study, we measured salivary IgA and IgG antibodies induced by vaccination with a monovalent serogroup A conjugate vaccine or a tetravalent A, C, W and Y conjugate vaccine, in comparison with antibody levels in serum. Saliva and serum samples from Ethiopian volunteers (1-29 years) collected before and eight times on a weekly basis after receiving the serogroup A conjugate vaccine, the tetravalent serogroup A, C, W and Y conjugate vaccine, or no vaccine (control group), were analysed using a multiplex microsphere immunoassay for antibody detection. Serogroup-specific IgG antibody levels in saliva increased significantly after vaccination with both vaccines. The monovalent serogroup A vaccine also induced an increase in salivary IgA antibodies. A strong correlation between serogroup-specific IgG antibodies in saliva and serum, and a somewhat lower correlation for IgA, was observed for all serogroups. There was also a strong correlation between specific secretory IgA and IgA antibodies in saliva for all serogroups. Meningococcal conjugate vaccines are able to elicit salivary antibodies against serogroup A, C, W and Y correlating with antibody levels in serum. The strong correlation between saliva and serum antibody levels indicates that saliva may be used as a surrogate of systemic antibody responses.

Research paper thumbnail of Additional file 4 of An integrative approach to identify sand fly vectors of leishmaniasis in Ethiopia by morphological and molecular techniques

Additional file 4: Table S3 Interspecies K2P distances of cox1 gene of Phlebotomus sand flies of ... more Additional file 4: Table S3 Interspecies K2P distances of cox1 gene of Phlebotomus sand flies of the subgenus Adlerius.

Research paper thumbnail of Additional file 2 of An integrative approach to identify sand fly vectors of leishmaniasis in Ethiopia by morphological and molecular techniques

Additional file 2: Table S2. Interspecies K2P distances of cox1 and nad4 genes of Ethiopian sand ... more Additional file 2: Table S2. Interspecies K2P distances of cox1 and nad4 genes of Ethiopian sand flies. The lower left quadrant presents the K2P distances (SD) of the cox1 gene, the upper right quadrant of the nad4 gene. The nad4 gene of P. duboscqi specimens was not included in the analysisa.

Research paper thumbnail of Additional file 4 of An integrative approach to identify sand fly vectors of leishmaniasis in Ethiopia by morphological and molecular techniques

Additional file 4: Table S3 Interspecies K2P distances of cox1 gene of Phlebotomus sand flies of ... more Additional file 4: Table S3 Interspecies K2P distances of cox1 gene of Phlebotomus sand flies of the subgenus Adlerius.

Research paper thumbnail of An in vitro antibacterial activity and phytochemical analysis of Nicotiana tabacum L. sourced from the Western Ethiopia

The Open Microbiology Journal, 2017

Background: Controlling infectious disease using medicinal plants is the oldest healthcare known ... more Background: Controlling infectious disease using medicinal plants is the oldest healthcare known to mankind. Regardless of the enormous advances observed in modern medicine, medicinal plants are still playing vital roles. However, only a small proportion of medicinal plants are examined for bioactive compounds which may vary in different factors. This study aimed to evaluate phytochemical constituent and antimicrobial activities of Nicotiana tabacum L. extracted by different solvents against three set of bacteria. Methods: Nicotiana tabacum L. was collected from the Western Ethiopia and extracted in seven organic solvents. An in-vitro anti-bacterial activity of plant extracts was carried out by agar well diffusion assay against microbial type culture collection of human pathogens, clinical bacterial isolates, and biofilm forming bacteria. Gas Chromatographic and Mass Spectroscopic (GC-MS) analysis was used to determine the phytochemical constituents. Results: Antimicrobial activities of plant extract vary by extraction solvents; and ethyl acetate based extracts showed better antimicrobial activities. Of the experimental organisms, biofilm forming uropathogens were the most sensitive while clinical isolates were quite resistant. Analysis of the active ethyl acetate extract by GC-MS evinced a mixture of five volatile compounds; and Pyridine, 3-(1methyl-2-pyrrolidinyl)-, (S) was the major compound detected. The overall results of the present study revealed that N. tabacum L extract has high antimicrobial activities against biofilm forming uropathogens. Conclusion: High antimicrobial activity was observed in ethyl acetate extract of N. tabacum against the biofilm forming bacteria whereas the clinically isolated bacteria were the most resistant group. The antibacterial property demonstrated could be due to Pyridine, 3-(1methyl-2-pyrrolidinyl)-(S) with a broad spectrum of activity.

Research paper thumbnail of Additional file 2 of An integrative approach to identify sand fly vectors of leishmaniasis in Ethiopia by morphological and molecular techniques

Additional file 2: Table S2. Interspecies K2P distances of cox1 and nad4 genes of Ethiopian sand ... more Additional file 2: Table S2. Interspecies K2P distances of cox1 and nad4 genes of Ethiopian sand flies. The lower left quadrant presents the K2P distances (SD) of the cox1 gene, the upper right quadrant of the nad4 gene. The nad4 gene of P. duboscqi specimens was not included in the analysisa.

Research paper thumbnail of An in vitro antibacterial activity and phytochemical analysis of Nicotiana tabacum L. sourced from the Western Ethiopia

The Open Microbiology Journal, 2017

Background: Controlling infectious disease using medicinal plants is the oldest healthcare known ... more Background: Controlling infectious disease using medicinal plants is the oldest healthcare known to mankind. Regardless of the enormous advances observed in modern medicine, medicinal plants are still playing vital roles. However, only a small proportion of medicinal plants are examined for bioactive compounds which may vary in different factors. This study aimed to evaluate phytochemical constituent and antimicrobial activities of Nicotiana tabacum L. extracted by different solvents against three set of bacteria. Methods: Nicotiana tabacum L. was collected from the Western Ethiopia and extracted in seven organic solvents. An in-vitro anti-bacterial activity of plant extracts was carried out by agar well diffusion assay against microbial type culture collection of human pathogens, clinical bacterial isolates, and biofilm forming bacteria. Gas Chromatographic and Mass Spectroscopic (GC-MS) analysis was used to determine the phytochemical constituents. Results: Antimicrobial activities of plant extract vary by extraction solvents; and ethyl acetate based extracts showed better antimicrobial activities. Of the experimental organisms, biofilm forming uropathogens were the most sensitive while clinical isolates were quite resistant. Analysis of the active ethyl acetate extract by GC-MS evinced a mixture of five volatile compounds; and Pyridine, 3-(1methyl-2-pyrrolidinyl)-, (S) was the major compound detected. The overall results of the present study revealed that N. tabacum L extract has high antimicrobial activities against biofilm forming uropathogens. Conclusion: High antimicrobial activity was observed in ethyl acetate extract of N. tabacum against the biofilm forming bacteria whereas the clinically isolated bacteria were the most resistant group. The antibacterial property demonstrated could be due to Pyridine, 3-(1methyl-2-pyrrolidinyl)-(S) with a broad spectrum of activity.

Research paper thumbnail of An in vivo efficacy validation and immune-modulatory potential of Streptomyces sp

Journal of Coastal Life Medicine, 2015

An in vivo efficacy validation and immune-modulatory potential of Streptomyces sp.

Research paper thumbnail of An in vivo efficacy validation and immune-modulatory potential of Streptomyces sp

Journal of Coastal Life Medicine, 2015

An in vivo efficacy validation and immune-modulatory potential of Streptomyces sp.

Research paper thumbnail of An In Vitro Antibacterial and Cytotoxic Potentials of Bioactive Metabolites Extracted from Padina tetrastromatica

Translational Biomedicine, 2016

Marine brown algae, Padina tetrastromatica was extracted using diverse organic solvents of increa... more Marine brown algae, Padina tetrastromatica was extracted using diverse organic solvents of increasing polarity such as diethyl ether, chloroform, acetone, dichloromethane: methanol and methanol. The obtained extracts were evaluated for antibacterial and brine shrimp cytotoxicity assays. It was found that methanolic extract of P. tetrastromatica exhibited the broadest and highest range of antibacterial activity. In cytotoxic activity, the methanolic extract of P. tetrastromatica showed significant activity (LD 50 =354.4 µg/mL). Based on the present findings, it could be inferred that the bioassay guided purification and fractionation of crude methanolic extract of P. tetrastromatica may bring forth potent novel antibiotic and anticancer leads.

Research paper thumbnail of An In Vitro Antibacterial and Cytotoxic Potentials of Bioactive Metabolites Extracted from Padina tetrastromatica

Translational Biomedicine, 2016

Marine brown algae, Padina tetrastromatica was extracted using diverse organic solvents of increa... more Marine brown algae, Padina tetrastromatica was extracted using diverse organic solvents of increasing polarity such as diethyl ether, chloroform, acetone, dichloromethane: methanol and methanol. The obtained extracts were evaluated for antibacterial and brine shrimp cytotoxicity assays. It was found that methanolic extract of P. tetrastromatica exhibited the broadest and highest range of antibacterial activity. In cytotoxic activity, the methanolic extract of P. tetrastromatica showed significant activity (LD 50 =354.4 µg/mL). Based on the present findings, it could be inferred that the bioassay guided purification and fractionation of crude methanolic extract of P. tetrastromatica may bring forth potent novel antibiotic and anticancer leads.

Research paper thumbnail of Evaluating the Antibacterial Potential of Streptomyces sp

Translational Biomedicine, 2015

Background and Objectives: Marine bacteria are recognized as an untapped resource of bioactive me... more Background and Objectives: Marine bacteria are recognized as an untapped resource of bioactive metabolites of diverse structure and functions. The present research is focused on the screening of the antagonistic potential of bacteria isolated from marine sponge against human and shrimp pathogens. Methods and Findings: In this study, a total of 51 strains of bacteria isolated from five species of marine sponges sourced from the Vizhinjam littoral (Indian Ocean) were screened for possible antagonistic activity against human and shrimp pathogens. Of the 51 bacterial isolates, twelve strains isolated from marine sponges, S.officinalis and D. nigra showed different ranges of activity. The results of agar-well diffusion assay showed that, out of the twelve strains, MAPS 15 strain showed the highest activity which subdued the growth of all the tested 20 bacterial pathogens. The molecular characterization based on partial 16S rRNA sequence revealed that the active isolate MAPS 15 was Streptomyces sp. Conclusion: This study serves as a basis for further research on the possibility of utilizing Streptomyces sp. for the development of human and veterinary grade antibiotics.

Research paper thumbnail of An in vitro antibacterial and anticandidal activity of Sonneratia alba (J. Smith)

Research paper thumbnail of In vitro antibacterial activity of medicinal plant extracts against Escherichia coli strains from human clinical specimens and interactions with antimicrobial drugs

Natural Product Research, 2012

Objective: Various diseases are caused by different pathogenic microorganisms. Antibiotics are be... more Objective: Various diseases are caused by different pathogenic microorganisms. Antibiotics are being used for treatment of these infectious diseases, yet unpredictable utilization of it leads towards antibacterial resistance. It is required to discover better approaches to battle against antibacterial resistance. Therefore, the study aimed to detect antibacterial sensitivity of ethanol extracts of Curcuma longa (turmeric), Cinnamomumzeylanicum (clove) and Syzygiumaromaticum (cinnamon) against Syaphylococcus aureus and E coli. Methods: Prior to sensitivity testing, ethanol oils were extracted by an electric blender and each of the bacteria strains were cultured onto blood agar plate. Antibacterial activity was tested by agar well diffusion method where three different concentrations (50 μl, 75 μl and 100 μl) of selected plants extract were used so far as to measure the inhibition zone. Inhibition zone of the ethanol extract of these plants were calculated where three were found to be sensitive against Syaphylococcus aureus and E coli. Results: Greater inhibition zone 14.5 mm, 18.25 mm, 21.5 mm at100 μl against Syaphylococcus aureus in case of cinnamon whereas the least inhibition zone was showed by turmeric and it was 9.00 mm, 11.00 mm, and 12.75 mm at 100 μl extract against E. coli. Conclusion: Overall, all the ethanol extracts were found to effective against these two bacteria but cinnamon can be used as more effective antibacterial agent in both human and veterinary field after the toxicological test.

Research paper thumbnail of Additional file 3 of An integrative approach to identify sand fly vectors of leishmaniasis in Ethiopia by morphological and molecular techniques

Additional file 3: Figure S1. Comparison of MALDI-TOF MS protein profiles of Ethiopian Adlerius s... more Additional file 3: Figure S1. Comparison of MALDI-TOF MS protein profiles of Ethiopian Adlerius sp. with five other species of the subgenus Adlerius. Zoomed mass range of 4 to 15 kDa is depicted.

Research paper thumbnail of Additional file 1 of An integrative approach to identify sand fly vectors of leishmaniasis in Ethiopia by morphological and molecular techniques

Additional file 1: Table S1. Intraspecies K2P distances of cox1 and nad4 genes of Ethiopian sand ... more Additional file 1: Table S1. Intraspecies K2P distances of cox1 and nad4 genes of Ethiopian sand flies. Abbreviations: K2P, Kimura 2-parameter model; SD, standard deviation.

Research paper thumbnail of Additional file 3 of High-resolution habitat suitability model for Phlebotomus pedifer, the vector of cutaneous leishmaniasis in southwestern Ethiopia

Additional file 3: Figure S2. Dependence of the predicted suitability on the six least contributi... more Additional file 3: Figure S2. Dependence of the predicted suitability on the six least contributing variables. The curves show how the prediction changes as each environmental variable is varied, keeping all other environmental variables at their average sample value. The cloglog value provides an estimate between 0 and 1 of probability of presence. Abbreviations: EVIdry, enhanced vegetation index in the dry season; Pdry, precipitation in the driest months; Pmean, mean precipitation; Cliffs, ordinal categorical values indicating cliffs between 20–40% and above 40%; EVIwet, enhanced vegetation index in the wet season.

Research paper thumbnail of Additional file 2 of High-resolution habitat suitability model for Phlebotomus pedifer, the vector of cutaneous leishmaniasis in southwestern Ethiopia

Additional file 2: Table S1. Percent variable contribution and jackknife estimates indicating the... more Additional file 2: Table S1. Percent variable contribution and jackknife estimates indicating the most important variables for the model. Abbreviations: SD, standard deviation; Tmean, mean temperature; Pseas, precipitation seasonality; EVIdry, enhanced vegetation index in the dry season; Pdry, precipitation in the driest months; Pmean, mean precipitation; Cliffs, ordinal categorical values indicating cliffs between 20–40% and above 40%; EVIwet, enhanced vegetation index in the wet season.