Antibacterial activity of coffee extract against common human bacterial pathogens in a teaching hospital of semi urban setup

Background: Coffee has a stimulant nature for which it is consumed worldwide, especially in Indian subcontinent. It also contains various antioxidant and antibacterial properties and is good for health. Aims and Objectives: This study done in tertiary care teaching hospital, aims to assess the antibacterial activity of coffee extract in surgical wound infections. Materials and Methods: The antibacterial activity of coffee extract against pathogenic bacteria (Gram-positive and Gram-negative) isolated from the surgical wounds was tested. Results: Both Gram-positive and Gram-negative bacteria were found sensitive to the methanol coffee extract. Conclusion: Our study revealed that coffee extract can be used in the future as a substitute antimicrobial for the treatment of pathogenic bacteria due to its wide antimicrobial activity and we suggest advanced study on coffee extract to explore the bioactive compounds accountable for the detected antimicrobial activity.

Antibacterial and Antibiofilm Activities of Crude Extract of Lasiodiplodia pseudotheobromae IBRL OS-64 against Foodborne Bacterium, Yersinia enterocolitica

The antibacterial and antibiofilm activities of crude extract of Lasiodiplodia pseudotheobromaeIBRL OS-64 was studied and tested against a foodborne pathogenic bacterium, Yersinia enterocolitica. The ethylacetate extract exhibited favorable antibacterial activity with the zone of inhibition was 20.3±0.6 mm compared to dichloromethane (15.0±0.3 mm) and butanol (9.0±0.3 mm) extracts. Minimum inhibition concentration (MIC) and minimum bactericidal concentration (MBC) values of the extract were 125 and 250 μg/mL, respectively. Structural degeneration studies through scanning electron microscopy (SEM) and transmission electron microscope (TEM) micrographs exhibited major abnormalities that occurred on thebacterial cells after exposureto the extract were complete alterations in their morphology and collapsed of the cells beyond repair. The findings showed that the extract possesses antibiofilm activity against the initial and preformed biofilm of Y. enterocoliticawith the highest inhibition value of 69.12% and 58.70%, respectively The results also revealed the initial biofilm was more susceptible to the extract as compared to pre-formed biofilm. The light microscopy (LM) and SEM photomicrographs proved that thefungal extract significantly eliminates extracellular polysaccharide (EPS) matrices and hinder the attachment of the bacterial cells for biofilm formation. Therefore, the current study suggested the ethyl acetate crude extract from an endophytic fungus, L. pseudotheobromae IBRL OS-64 may be an effective antibacterial and anti-biofilm agent to treat foodborne pathogens

Antibacterial efficacy of black seed honey in combination with penicillin and amoxiclav against gram-positive bacteria

Background:The emergence of antimicrobial resistance possessesa great threat for the existence of mankind. Antibiotics like penicillin and amoxiclav are at the brink of losing their efficacy entirely in exposure to resistant bacteria. Thus, the present study was aimed to find out the antibacterial efficacy of black seed honey as an alternative natural source which can act independently and boost the efficacy of standard drugs alongside. Methods:Penicillin, amoxiclav and black seed honey were first individually trailedagainst four gram-positive bacteria -Bacillus subtilis, Staphylococcus aureus, Staphylococcus epidermidis andMicrococcus luteus.Afterwards, penicillin and amoxiclav were used in combination with honey and compared the synergistic effects with their individual efficacy. Zones of inhibition from well diffusion method, percentage inhibition, minimum inhibitory and bactericidal concentrations by microdilution method were determined in the present study.Results:Black seed honey alone demonstrated great inhibitory potential against S. aureus (9.7 mm), S. epidermidis (9.9 mm) and M. luteus(9.3 mm) in well diffusion method. Moreover, its combination with amoxiclav showed synergistic effect against all bacteria except S. epidermidis. However, its conjugation with penicillin was not able to produce any synergism as exhibited by zones of inhibition. The lowest concentration (1.56%) of honey applied individually or in combination in microdilution method foundhighly effective which established an inverse dose dependent relationship with efficacy.Conclusions:From the data it can be concluded that the black seed honey is a highly potent natural agent which can be utilized in antimicrobial therapy. However, further investigation is recommended to identify the responsible compound for such activity.

Antibacterial Activity of Locally Prepared Herbal Cough Extracts against Klebsiella pneumoniae and Streptococcus pneumoniae

Aim: Cough due to Klebsiella pneumoniae andStreptococcus pneumoniae is currently managed by conventional antibiotics and herbal extracts in Uganda. However, much as these herbal extracts are extensively used, their antibacterial activity is not known. This study aimed at determining the antibacterial activity of the selected locally prepared herbal cough extracts against two bacterial strains i.e. Klebsiella pneumoniae (ATCC 700603), and Streptococcus pneumoniae (ATCC 49619). Methods: The herbal cough extracts were screened for antibacterial activity using Agar-well diffusion method for determining zone of inhibition, macro broth dilution method for Minimum Inhibitory Concentration (MIC) determination and Streak plate method for Minimum Bactericidal Concentration (MBC). Results:In vitro evaluation of antibacterial activity of the 5 brands of herbal cough extracts against K. pneumoniae and S. pneumoniae revealed that all extracts possessed significant antimicrobial effects against all microorganisms tested (p < 0.05). However, MM04 (35.6±0.0) mm and MM03 (33.6±1.5) mm had maximum zones of inhibition as compared to other herbal extracts against K. pneumoniae and S. pneumoniae respectively. Average MIC results for extracts against K. pneumoniae indicated that MM01 had the highest MIC (2.5000 mg/ml) while MM03 had the least MIC (0.0625 mg/ml). Average MIC results for extracts against S. pneumoniae showed MM01 had the highest MIC (2.0000 mg/ml) while MM03 3 had the least MIC (0.0438 mg/ml). Average MBC results for extracts against K. pneumoniae indicated that MM01 had the highest MBC (4.000 mg/ml) while MM03 had the least MBC (0.030 mg/ml). Average MBC results for extracts against S. pneumoniae showed MM01 had the highest MBC (4.000 mg/ml) while MM03 had the least MBC (0.033 mg/ml). Conclusion: The results obtained in present study were revealed that locally prepared herbal extracts had significant antibacterial activity. Hence they can be used as promising alternatives of antibiotics used against Respiratory Tract Infections due to K. pneumoniae and S. pneumoniae.

Time-kill assay and post-antibiotic effect of acetone extract from the stem bark of Canarium odontophyllum against Methicillin-resistant Staphylococcus aureus Mu50 strain

Canarium odontophyllum Miq. is an indigenous fruit found in Sarawak, Malaysia. Methicillin-resistant Staphylococcusaureus (MRSA) is a deadly pathogen that causes to hospital (health-care-acquired MRSA [HA-MRSA]) and community(CA-MRSA) infections worldwide. Vancomycin has been the therapeutic drug of choice against MRSA, but unfortunatelythis pathogen has developed some degree of resistance to vancomycin. This research aimed to evaluate the antimicrobialactivity of the stem bark extract of C. odontophyllum against MRSA Mu50 strain. The minimum inhibitory concentration(MIC) and minimum bactericidal concentration (MBC) of extract and vancomycin against MRSA were determined usingbroth microdilution method and streak plate method. The rate of killing by the extract against Mu50 strain was determinedusing time-kill assay (TKA) at ×1 MIC, ×2 MIC, ×4 MIC, and ×8 MIC of the extract. The post-antibiotic effect (PAE) timeof extract ×10 MIC against MRSA was also investigated. The extract exhibited bacteriostatic effect against MRSA Mu50strain with MIC and MBC values of 1.563 mg/ml and 3.125 mg/ml, respectively. From TKA analysis, the extract was notcapable of killing the Mu50 strain at ×1 MIC and ×2 MIC, but it displayed bactericidal activity at higher concentrationstested. Interestingly, the acetone stem bark extract of C. odontophyllum at ×4 MIC showed comparable time-killingkinetic with the standard antibiotic in the study. The PAE time of the extract was 3.6 ± 0.51 h against MRSA Mu50compared to vancomycin at 2.4 ± 0.68 h. In conclusion, the stem bark acetone extract from C. odontophyllum demonstratedconcentration-dependent bactericidal effect with prolonged PAE time against MRSA Mu50 strain.

Antibacterial Activity of Acacia nilotica Stem-Bark Fractions against Staphylococcus aureus and Escherichia coli

Aims:This research was carried out to determine the antibacterial activity of Acacia nilotica stem bark extract and bioactive fractions against the test bacteria (Staphylococcus aureusand Escherichia coli). Place and Duration of Study:Acacia niloticawas collected within Aliero town, Kebbi State, Nigeria between April and September, 2017. Methodology:The crude and bioactive fractions were obtained using soxhlet extraction and column chromatographic methodrespectively. The qualitative phytochemical screening was conducted to detect the presence of some phytochemical constituents in the crude extract and fractions. The antibacterial activity was determined at various concentrations (10, 50, 100, 150 and 200mg/ml) using disc diffusion method Results:The crude antibacterial activity indicated that ethanol extract showed higher activity than the n-hexane extract with 14.0±0.00 and 12.0±0.00 mm zones of inhibition compared with the control drug (10μg Ciprofloxacin drug), which showed 14.0±0.00 and 13.0±0.00 mm zone of inhibition against the test bacteria. The MIC and MBC values determined for ethanol extracts against the test bacteria was 12.5 mg/ml and 25 mg/ml, while the MIC and MBC values obtained for n-hexane extracts were 25 and 50 mg/ml against the test bacteria. The bioactive fractions (Yellow, Purple and Blue Black Fractions) tested against the test bacteria showed higher activity compared with the crude extract. The phytochemical properties of the plant crude extract and the bioactive fractions indicated the presence of phenol, tannins, alkaloids, saponins, flavonoids, terpenoids, steroids and glycosides and this attributed to the high antibacterial activities of 17.0±0.00and 16.0±0.00mm showed by the fractionsagainst Staphylococcus aureus and 15.67±and 14.0±0.00mm against Escherichia coli respectively. Conclusion:Acacia niloticacrude extract and fractions exhibited antibacterial activity which was comparable to the standard drug ciprofloxacin. This validates the folkloric medicinal use of this plant by the indigenous people of Aliero, Kebbi State

Evaluation of in vitro Antibacterial Activity of the Extracts from Root ，Stem and Leaves of Psychotria rubra and Its Mechanism Study / 中国药房

OBJECTIVE： To investigate in vitro antibacterial activity of the extracts from the root， stem and leaves of Psychotria rubra， and to investigate its mechanism of antibacterial effects. METHODS： 95％ ethanol extracts from the root， stem and leaves of P. rubra were used to prepare solution with mass concentration of 100 mg/mL （calculated by extract）. Using as penicillin sodium （0.5 mg/mL） and streptomycin sulfate （128 mg/mL） as positive control， plat stiletto method was used to determine antibacterial effects of the extracts from different parts of Staphylococcus aureus， Escherichia coli， Pseudomonas aeruginosa， Bacillus subtilis， Micrococcus luteus and Enterococcus faecalis. Using systematic solvent extraction method， the petroleum ether， ethyl acetate and n-butyl alcohol were used to extract antibacterial activity parts from P. rubra as ad to obtain the extracts of corresponding polar parts. After preparing 100 mg/mL drug solution （calculated by extract）， antibacterial effects of above 6 kinds of bacteria were investigated. The micro-broth dilution method and agar culture medium plate method were used to determine minimum inhibitory concentration （MIC） and minimum bactericidal concentration （MBC）， and screen polar parts with bacteriostasis and drug-sensitive strains. Under the concentration of 0.5MIC and MIC， the growth curves of sensitive bacteria were drawn （treated for 36 h， every 4 h）； the contents of alkaline phosphatase （AKP） and soluble protein were detected in suspension （treated for 10 h， every 2 h）； bouillon culture medium instead of the extract as blank control. RESULTS： 100 mg/mL ethanol extracts from the root， stem and leaves of P. rubra showed good antibacterial effect to above 6 kinds of bacteria， in descending order as stem＞leaves＞root. Among different polar parts from the stem of P. rubra， antibacterial effect of the ethyl acetate extract was best， especially for the S. aureus， the diameter of inhibition zone reached （38.93±0.12） mm， and both MIC and MBC were 0.39 mg/mL. The ethyl acetate extract could significantly inhibit the proliferation of S. aureus， and its alkaline phosphatase and protein content in suspension were increased significantly compared with blank control （P＜0.05）. CONCLUSIONS： The stem from P. rubra is effective antibacterial parts， and exhibit good antibacterial activity to 6 kinds of common pathogens. The ethyl acetate extract from the stem of P. rubra shows strongest antibacterial effect on S. aureus， and could gradually destroy the integrity of cell wall and cell membrane.

Antiseptic effect of compound lysostaphin disinfectant and its preventive effect on infection of artificial dermis after graft on full-thickness skin defect wound in rats / 中华烧伤杂志

Objective@#To study the antiseptic effect of compound lysostaphin disinfectant and its preventive effect on infection of artificial dermis after graft on full-thickness skin defect wound in rats.@*Methods@#(1) Each one standard strain of Klebsiella pneumoniae, Acinetobacter baumannii, and Staphylococcus aureus were selected. Each 20 clinical strains of Klebsiella pneumoniae, Acinetobacter baumannii, and Staphylococcus aureus were collected from those isolated from wound exudates of burn patients hospitalized in our wards from January 2014 to December 2016 according to the random number table. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of compound lysostaphin disinfectant to above-mentioned strains were detected. The experiment was repeated 3 times. Compared with the corresponding standard strain, the clinical strain with higher MIC and/or MBC was considered as having decreased sensitivity to the disinfectant. The percentage of strains of each of the three kinds of bacteria with decreased sensitivity was calculated. (2) Artificial dermis pieces were soaked in compound lysostaphin disinfectant for 5 min, 1 h, 2 h, and 4 h, respectively, with 21 pieces at each time point. After standing for 0 (immediately), 12, 24, 36, 48, 60, 72 h (with 3 pieces at each time point), respectively, the diameters of their inhibition zones to standard strains of Klebsiella pneumoniae, Acinetobacter baumannii, and Staphylococcus aureus were measured. The experiment was repeated 3 times. The shortest soaking time corresponding to the longest standing time, after which the disinfectant-soaked artificial dermis could form an effective inhibition zone (with diameter more than 7 mm), was the sufficient soaking time of the disinfectant to the artificial dermis. (3) Forty Sprague-Dawley rats were divided into post injury day (PID) 3, 7, 14, and 21 sampling groups according to the random number table, with 10 rats in each group. A full-thickness skin defect wound with a diameter of 20 mm was made on both sides of the spine on the back of each rat. Immediately after injury, the artificial dermis without any treatment was grafted on the wound on left side of the spine (hereinafter referred to as control wound), while the sufficiently soaked artificial dermis with compound lysostaphin disinfectant was grafted on the wound on right side of the spine (hereinafter referred to as disinfectant wound). On PID 3, 7, 14, and 21, the gross condition of wounds of all the surviving rats was observed, and the new infection rates of control wounds and disinfectant wounds were calculated. Then, the rats in the sampling group with corresponding time were killed, and the full-thickness wound tissue containing artificial dermis was collected for quantitative analysis of bacteria. Bacteria content of the uninfected control wounds and that of the uninfected disinfectant wounds were compared. Data were processed with chi-square test and Wilcoxon rank sum test.@*Results@#(1) The MIC of compound lysostaphin disinfectant to standard strains of Staphylococcus aureus, Klebsiella pneumoniae, and Acinetobacter baumannii were 1/32, 1/32, and 1/512 of the original concentration of the disinfectant, respectively, and the MBC were 1/32, 1/16, and 1/512 of the original concentration of the disinfectant, respectively. The percentages of clinical strains of Klebsiella pneumoniae, Acinetobacter baumannii and Staphylococcus aureus with decreased sensitivity to compound lysostaphin disinfectant were 15% (3/20), 20% (4/20), and 10% (2/20), respectively. (2) After being soaked in compound lysostaphin disinfectant for 2 and 4 h, the longest standing time, after which the artificial dermis could form an effective inhibition zone against Klebsiella pneumoniae, Acinetobacter baumannii, and Staphylococcus aureus, were 24, 36, and 48 h respectively, longer than 12, 24, and 24 h of soaking for 5 min and 24, 24, and 36 h of soaking for 1 h. The sufficient soaking time of compound lysostaphin disinfectant to artificial dermis was 2 h. (3) On PID 3, no infection symptom was observed in all the wounds, and so both the new infection rate of control wounds and that of disinfectant wounds were 0. The artificial dermis was transparent but not well connected with the wound. On PID 7, the new infection rate of control wounds was 20.00% (6/30), which was obviously higher than 3.33% (1/30) of disinfectant wounds, χ2=4.043, P<0.05. On the infected wound, a large amount of purulent exudates were observed, and the artificial dermis was not connected with the wound and degraded partially. On the uninfected wound, artificial dermis was transparent and had a partial connection with the wound. On PID 14 and 21, no new infected wound was observed, and so both the new infection rate of control wounds and that of disinfectant wounds were 0. There was no obvious improvement on the infected wounds. The collagen layers of artificial dermis in the uninfected wound established a good connection with the wound and were separating from the silica gel layer gradually. Infection occurred in 2, 3, 1 control wound (s) in PID 7, 14, and 21 sampling groups, respectively, and in 1 disinfectant wound in PID 14 sampling group. The bacteria content of the infected wounds tissue was 0.79×106 to 7.22×109 colony-forming unit (CFU)/g. The bacteria content of uninfected control wounds tissue in PID 3, 7, and 14 sampling groups were (3.43±1.88)×102, (2.37±0.43)×103, and (8.40±1.03)×103 CFU/g, respectively, which were significantly higher than (0.33±0.12)×102, (0.43±0.17)×103, (2.16±0.52)×103 CFU/g of uninfected disinfectant wounds tissue (Z=-3.780, -3.554, -3.334, P<0.05). The bacteria content of uninfected control wounds tissue and that of uninfected disinfectant wounds tissue in PID 21 sampling group were similar (Z=-0.490, P>0.05).@*Conclusions@#Compound lysostaphin disinfectant has quite strong antibacterial ability against Klebsiella pneumoniae, Acinetobacter baumannii, and Staphylococcus aureus. Clinical strains of the three kinds of bacteria were highly sensitive to compound lysostaphin disinfectant. Saturation of absorption of compound lysostaphin disinfectant achieves in artificial dermis after 2 hours′ soaking. After 24, 36, and 48 hours′ standing, the soaked artificial dermis still has the antibacterial effect on Klebsiella pneumoniae, Acinetobacter baumannii, and Staphylococcus aureus, respectively. The infection rate and the bacteria content of full-thickness skin defect wound in rats are all decreased when grafted with soaked artificial dermis.

Antimicrobial Activities of Daucus Carota Seeds on Selected Pathogenic Micro-organisms

Background: The antibacterial/antifungal toxicity of Daucus carota (carrot) seeds was evaluated using selected multi-drug resistant bacteria and yeast of clinical origin. Methods: The active constituents of the Daucus carota seeds were extracted using conventional Plant Tissue Homogenization method using cold distilled water, Ethanol and Methanol as solvents. Varying concentrations (5-250 mg/ml) of the three extracts were assayed for antimicrobial activity against the selected isolates- Salmonella typhi, Staphylococcus aureus, Escherichia coli, Klebseilla pneumoniae and Candida albicans; the agar well diffusion method was used. The antibiogram profile of the organisms was also obtained through disc diffusion method. Results: Similar activity was observed in the methanolic and ethanolic extracts while cold distilled water showed no activity on any of the isolates. The antibiotic susceptibility results showed that the isolates used are highly multi-drug resistant. Ofloxacin exhibited the most pronounced activity against all the isolates. Gentamicin and erythromycin both showed activity on Escherichia coli and Salmonella typhi. Lower concentrations of both extracts presented no inhibitory effects on the test organisms, thus resulting in high MIC values recorded for both extracts. Also, the extracts showed no bactericidal action against the isolates.  Conclusions: Observations from this research therefore affirm that Daucus carota seeds possess antimicrobial properties that may be explored as a source of future antimicrobial compounds.

Study on in vitro Antibacterial Effect of Extracts from Miao Medicine Rubus multibracteatus Leaves / 中国药房

OBJECTIVE:To investigate in vitro antibacterial effect of extracts from Miao medicine Rubus multibracteatus leaves. METHODS:The aqueous extract and 80% ethanol extracts from R. multibracteatus leaves were used to prepare solution with mass concentration of 200 mg/mL. Using ampicillin and fluconazol as positive control (50 mg/mL),cup plate method was used to determine antibacterial effects of the extracts from R. multibracteatus leaves to Staphylococcus aureus,Staphylococcus epi-dermidis,Escherichia coli,Shigella dysenteriae,Proteus vulgaris,Candida albicans and Cryptococcus neoformans. The petroleum ether,acetic ether and n-butyl alcohol were used to extract 80% ethanol extracts in turns. After obtaining relevant extracts (50 mg/mL),cup plate method was used to investigate antibacterial effects of them to above 7 bacterial strains. The parts with antibacte-rial effects and bacterial strains sensitive to drug were screened. Micro-broth dilution method and agar culture medium plate method were used to determine minimum inhibitory concentration(MIC)and minimum bactericidal concentration(MBC). RESULTS:The aqueous extract of R. multibracteatus leaves almost had no inhibitory effect while 80% ethanol extract showed different degrees of antibacterial effect to tested bacterial strains,and it also had higher activity against 5 bacterial stains than 2 fungus. The ethyl ace-tate and n-butyl alcohol fractions of 80% ethanol extracts showed good effect while the petroleum ether and water layer fractions had no antibacterial effect,and all the fractions of 80% ethanol extracts showed no inhibitory effect on fungus. To 5 bacterial stains,MIC and MBC of 80% ethanol extract were 6.25-12.5,12.5-25 mg/mL,those of ethyl acetate fractions were 3.13,6.25 mg/mL and those of n-butyl alcohol fraction were 3.13-6.25,6.25-12.5 mg/mL,respectively. CONCLUSIONS:80% ethanol ex-tract of Miao medicine R. multibracteatus leaves and its ethyl acetate and n-butyl alcohol fractions have obvious in vitro antibacteri-al effect to bacteria.

Synthesis and antibacterial activity of novel 2-(arylimino)thiazolidin-4-one and 2-(benzylidenehydrazono)-3-arylthiazolidin-4-one derivatives.

The ongoing spread of multidrug-resistant bacteria demands an intensive search for new antibacterial agents. In the present study, a series of new 1,3-thiazolidin-4-ones has been synthesized and investigated for its in vitro antibacterial activity. The most potent antibacterial compound 4c was found to be active, at low micromolar range, against Staphylococcus aureus, Staphylococcus epidermidis, Enterococcus faecalis and the pneumonic plague causative agent Yersinia pestis with minimum inhibitory concentrations of 5 μM, 2.5 μM, 2.5 μM and 5 μM, respectively. Compound 4c showed the ability to kill E. faecalis JH212 strain with a minimum bactericidal concentration of 5 μM. Furthermore, compounds 9b and 10a inhibited the biofilm formation in S. epidermidis, where they showed 70% to 80% inhibition at a concentration of 40 μM.

Avaliação da atividade antimicrobiana da planta Tradescantia pallida Munt (Taboquinha Roxa) / Evaluation of antimicrobial activity of the Tradescantia pallida Munt plant (Taboquinha Roxa)

RESUMO O objetivo deste estudo foi pesquisar o efeito antimicrobiano in vitro do extrato hidroalcóolico das folhas Tradescantia pallida Munt conhecida como Taboquinha roxa. Foram realizados testes em meio sólido, onde não observou qualquer halo de inibição, e o método de microdiluição, em que os resultados foram expressivos, com determinação da Concentração Inibitória Mínima (CIM) e Concentração Bactericida Mínima (CBM), com resultados em diferentes concentrações. Foram utilizadas cepas padrão de bactérias Gram positivas e Gram negativas. De acordo com os resultados, sugere-se que essa planta apresenta um potencial antimicrobiano.

ABSTRACT The aim of this study was to investigate the in vitro antimicrobial effect of the hydroalcoholic extract of the Tradescantia pallida Munt leaves,known as Taboquinha roxa. The tests were both conducted on solid mean, where it was not observed any zone of inhibition, and by the micro dilution method, in which the results of the Minimum Inhibitory Concentration (MIC) and the Minimum Bactericidal Concentration (MBC) were significant and related with the different concentrations. Standard strains of bacteria type Gram positive and Gram negative were employed. According to the results, this plant has an antimicrobial potential.

Phytochemical and Anti-microbial Screening of the Leaves and Twigs of Sclerocarpus africanus (Jacq).

Aim: To determine phytochemical constituents and antimicrobial activity of leaves and twigs of Sclerocarpus africanus (Jacq); prove or otherwise ethno-medicinal claims on S. africanus. Place and Duration of Study: Departments of Chemistry, Biological sciences and Microbiology, Ahmadu Bello University Teaching Hospital, Zaria, between June to October, 2010. Methodology: Petroleum ether, ethyl acetate, ethanol and methanol extracts of leaves and twigs of S. africanus were phytochemically screened for the presence of carbohydrates, saponins, tannins, alkaloids, anthraquinone glycosides and flavonoids. Minimum bactericidal/fungicidal concentrations (MBC)/(MFC) and Minimum inhibition concentration (MIC) were carried out on the extracts using Broth dilution method. Results: Phytochemical screening showed presence of carbohydrates, tannins and saponins. Flavonoids and anthraquinone glycosides were found only in the ethanol and methanol extracts. Anti-microbial screening of methanol and ethanol extracts showed activity against the following human pathogens: Staphylococcus aureus, Salmonella typhi, Streptococcus pyogenes, Shigella dysenteriae, Candida albicans and Candida thrusei, with MIC value of 2.5 mg/ml; while Neisseria gonorrhea was inhibited at MIC 1.25 mg/ml. MBC/MFC value of 10 mg/ ml was observed for all the pathogens, except N. gonorrhea which had an observered MBC of 5 mg/ ml for ethanol extract. Similar MBC/MFC values were obtained for methanol extract except Shigella dysentereae which had MBC of 5 mg/ ml. Petroleum ether extract was active against S. aureus, S. typhi, S. dysenteriae and N. gonorrhoea with MIC value of 5 mg/ml and MBC/MFC value 10 mg/ml; no activity was observed for S. pyogenes, C. albicans and C. thrusei; N. gonorrhea was most inhibited. Conclusion: Results obtained justify the ethno-medicinal use of this plant in treatment of gonorrhea and other venereal diseases caused by the test micro organisms.

Bioactivity and stability study of the antifungal substance produced by Streptomyces NG-715 / 中国生化药物杂志

Objective To explore the bioactivity and stability of the antifungal substance produced by Streptomyces NG-715 as well as to establish the assay for biological activity detection. Method Take the antifungal substance as experimental materials, and test its minimum inhibitory concentration and minimum bactericidal concentration on four fungi strains including Saccharomyces cerevisiae, Penicillium citrinum, Aspergillus niger, Rhizopus sp. Aspergillus niger was used as indicator strain to measure the biological activity and stability of the antifungal substance. Results The results showed that the MIC of the antifungal substance on four fungi strains including Saccharomyces cerevisiae,Penicillium citrinum,Aspergillus niger,Rhizopus sp were 1.25, 2.5, 3.75 and 3.75μg/mL, respectively. The MBC of the antifungal substance on four fungi strains were 2.5, 10, 17.5 and 17.5μg/mL, respectively. Linearity regress equation of the antifungal substance in Aspergillus niger was y=26.963 x-27.6,R 2=0.9991. The antifungal substance was pH-stable, heat-stable but ultravio1 et-sensible. Conclusion The results from this study will porvide useful information for the further extraction and analysis on the bioactive compound.

Actividad Antibacteriana in vitro de extractos y fracciones de Physalis peruviana L. y Caesalpinia pulcherrima (L.) Swartz / In vitro antibacterial activity of extracts and fractions of Physalis peruviana L. and Caesalpinia pulcherrima (L.) Swartz

We evaluated the in vitro antibacterial activity of extracts and fractions of Physalis peruviana L. calyces and flowers and leaves of Caesalpinia pulcherrima (L.) Swartz against ATCC strains Staphylococcus aureus, Klebsiella pneumoniae and Pseudomonas aeruginosa, determining the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). We find potent activity with MIC < 0,256 mg/mL for the chloroform fraction of P. peruviana calyces, the ethanol fraction of flowers of C. pulcherrima and ethanol and ether fractions of leaves of C. pulcherrima. Based on these results, we conclude that both species are promising and it is recommended to continue exploring them in order to isolate, purify and to elucidate the chemical structure from those compounds responsible for the biological activity of each active fraction.

Se evaluó la actividad antibacteriana in vitro de extractos y fracciones de los cálices de Physalis peruviana L. y flores y hojas de Caesalpinia pulcherrima (L.) Swartz frente a cepas ATCC de Staphylococcus aureus, Klebsiella pneumoniae y Pseudomonas aeruginosa, determinando la concentración mínima inhibitoria (CMI) y la concentración mínima bactericida (CMB). Encontramos potente actividad, con valores de CMI < 0,256 mg/mL para la fracción en cloroformo de los cálices de P. peruviana, la fracción en etanol de las flores de C. pulcherrima y las fracciones en etanol y éter de las hojas de C. pulcherrima. En función de los resultados obtenidos, concluimos que ambas especies son promisorias y se recomienda continuar su estudio intentando aislar, purificar y dilucidar la estructura química de los compuestos responsables de la actividad biológica en cada fracción activa.

Research on dose-effect relationship of Wuwei Xiaodu Drink on antibacterial metabolism by MSPQC / 中草药

Objective: The effect of Wuwei Xiaodu Drink (WXD) on the metabolism of bacteria and the dose-effect relationship were investigated by MSPQC. Methods: The frequency shift-time curves of the growth and metabolism of Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa affected by WXD were obtained by using MSPQC. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were gained according to FDT and the frequency shift. The dose-effect relationship was analyzed according to the curve which represented the relationship between the concentration of WXD and FDT. The parallel test was carried out with the traditional tube dilution method. Results: The results indicated that WXD inhibited the growth of E. coli, S. aureus, and P. aeruginosa, which was dose-dependent. The higher the concentration was, the stronger the antibacterial effect became. The MBC of WXD for three kinds of pathogenic bacteria was 0.9 g/mL. The MIC of WXD for S. aureus and P. aeruginosa was 0.8 g/mL, however for E. coli was 0.7 g/mL within 24 h. Conclusion: MSPQC is a sensitive, quantitative, quick method, which could provide the process information in real time for determining the dose-effect relationship of antimicrobial Chinese materia medica.

Combined antibacterial activity of stingless bee (Apis mellipodae) honey and garlic (Allium sativum) extracts against standard and clinical pathogenic bacteria

Objective:To investigate the synergic antibacterial activity of garlic and tazma honey against standard and clinical pathogenic bacteria. Methods:Antimicrobial activity of tazma honey, garlic and mixture of them against pathogenic bacteria were determined. Chloramphenicol and water were used as positive and negative controls, respectively. Minimum inhibitory concentration (MIC) and minimum bactericidal concentration of antimicrobial samples were determined using standard methods. Results: Inhibition zone of mixture of garlic and tazma honey against all tested pathogens was significantly (P≤0.05) greater than garlic and tazma honey alone. The diameter zone of inhibition ranged from (18±1) to (35±1) mm for mixture of garlic and tazma honey, (12±1) to (20±1) mm for tazma honey and (14±1) to (22±1) mm for garlic as compared with (10±1) to (30±1) mm for chloramphenicol. The combination of garlic and tazma honey (30-35 mm) was more significantly (P≤0.05) effective against Salmonella (NCTC 8385), Staphylococcus aureus (ATCC 25923), Lyesria moncytogenes (ATCC 19116) and Streptococcus pneumonia (ATCC 63). Results also showed considerable antimicrobial activity of garlic and tazma honey. MIC of mixture of garlic and tazma honey at 6.25%against total test bacteria was 88.9%. MIC of mixture of garlic and tazma honey at 6.25%against Gram positive and negative were 100%and 83.33%, respectively. The bactericidal activities of garlic, tazma honey, and mixture of garlic and tazma honey against all pathogenic bacteria at 6.25%concentration were 66.6%, 55.6%and 55.6%, respectively. Conclusions: This finding strongly supports the claim of the local community to use the combination of tazma honey and garlic for the treatment of different pathogenic bacterial infections. Therefore, garlic in combination with tazma honey can serve as an alternative natural antimicrobial drug for the treatment of pathogenic bacterial infections. Further in vivo study is recommended to come up with a comprehensive conclusion.

Properties of nanometer silver antibacterial agent and tetrapod-like zinc oxide antibacterial agent against Candida albicans / 中国组织工程研究

10.3969/j.issn.2095-4344.2013.25.007

Screening antimicrobial activity of various extracts of Urtica dioica

Urtica dioica or stinging nettle is traditionally used as an herbal medicine in Western Asia. The current study represents the investigation of antimicrobial activity of U. dioica from nine crude extracts that were prepared using different organic solvents, obtained from two extraction methods: the Soxhlet extractor (Method I), which included the use of four solvents with ethyl acetate and hexane, or the sequential partitions (Method II) with a five solvent system (butanol). The antibacterial and antifungal activities of crude extracts were tested against 28 bacteria, three yeast strains and seven fungal isolates by the disc diffusion and broth dilution methods. Amoxicillin was used as positive control for bacteria strains, vancomycin for Streptococcus sp., miconazole nitrate (30µg/mL) as positive control for fungi and yeast, and pure methanol (v/v) as negative control. The disc diffusion assay was used to determine the sensitivity of the samples, whilst the broth dilution method was used for the determination of the minimal inhibition concentration (MIC). The ethyl acetate and hexane extract from extraction method I (EA I and HE I) exhibited highest inhibition against some pathogenic bacteria such as Bacillus cereus, MRSA and Vibrio parahaemolyticus. A selection of extracts that showed some activity was further tested for the MIC and minimal bactericidal concentrations (MBC). MIC values of Bacillus subtilis and Methicillin-resistant Staphylococcus aureus (MRSA) using butanol extract of extraction method II (BE II) were 8.33 and 16.33mg/mL, respectively; while the MIC value using ethyl acetate extract of extraction method II (EAE II) for Vibrio parahaemolyticus was 0.13mg/mL. Our study showed that 47.06% of extracts inhibited Gram-negative (8 out of 17), and 63.63% of extracts also inhibited Gram-positive bacteria (7 out of 11); besides, statistically the frequency of antimicrobial activity was 13.45% (35 out of 342) which in this among 21.71% belongs to antimicrobial activity extracts from extraction method I (33 out of 152 of crude extracts) and 6.82% from extraction method II (13 out of 190 of crude extracts). However, crude extracts from method I exhibited better antimicrobial activity against the Gram-positive bacteria than the Gram-negative bacteria. The positive results on medicinal plants screening for antibacterial activity constitutes primary information for further phytochemical and pharmacological studies. Therefore, the extracts could be suitable as antimicrobial agents in pharmaceutical and food industry.

Urtica dioica u ortiga se utiliza tradicionalmente como medicina herbaria en el oeste de Asia. En esta investigación se estudia la actividad antimicrobiana de nueve extractos crudos de U. dioica, los cuales fueron preparados utilizando diferentes disolventes orgánicos y obtenidos a partir de dos métodos de extracción: el extractor Soxhlet (Método I), que incluía el uso de cuatro disolventes con acetato de etilo y hexano, y las particiones secuenciales (Método II) con un sistema de cinco disolventes (butanol). Las actividades antibacterianas y antifúngicas de extractos crudos fueron ensayados contra 28 bacterias, tres cepas de levadura y siete cepas fúngicas por la difusión en disco y el método de dilución en caldo. La amoxicilina se utilizó como control positivo para cepas de bacterias, vancomicina para Streptococcus sp., nitrato de miconazol (30μg/mL) como control positivo para los hongos y levaduras, y el metanol puro (v / v) como control negativo. El ensayo de difusión en disco se utilizó para determinar la sensibilidad de las muestras, mientras que el método de dilución en caldo se utilizó para la determinación de la concentración de inhibición mínima (CIM). El acetato de etilo y el extracto de hexano del método de extracción I (AE I y EH I) mostraron mayor inhibición contra algunas bacterias patógenas tales como Bacillus cereus, MRSA y Vibrio parahaemolyticus. Una selección de extractos que mostraron algún tipo de actividad se probó para el CIM y las concentraciones mínimas bactericidas (CMB). Los valores de CIM de Bacillus subtilis y de Staphylococcus aureus resistentes a la meticilina (MRSA) usando extracto de butanol mediante el método de extracción II (EB II) fueron: 8.33 y 16.33mg/ mL, respectivamente; mientras que el valor de MIC con el uso del extracto de acetato de etilo por el Método de extracción II (EAE II) para Vibrio parahaemolyticus fue 0.13mg/mL. Nuestro estudio mostró que el 47.06% de los extractos inhibieron bacterias Gram-negativas (8 de 17), y el 63,63% de los extractos también inhibieron bacterias Gram-positivas (7 de 11), además que estadísticamente la frecuencia de la actividad antimicrobiana fue de 13.45% (35 de 342), que de este porcentaje un 21.71% pertenece alos extractos de actividad antimicrobiana con el método de extracción I (33 de 152 de los extractos crudos) y un 6.82% del método de extracción II (13 de 190 de los extractos crudos). Sin embargo, los extractos crudos del método I exhibieron una mejor actividad antimicrobiana contra las bacterias Gram-positivas que las Gram-negativas. Los resultados positivos en la detección de plantas medicinales para la actividad antibacteriana constituye información primaria para la realización de nuevos estudios fitoquímicos y farmacológicos. Por lo tanto, los extractos podrían ser adecuados como agentes antimicrobianos en la industria farmacéutica y de alimentos.

Actividad bacteriostática y bactericida de la tintura de propóleos sobre bacterias enteropatógenas / Bacteriostatic and bactericidal activity of propolis tincture on enteropathogenic bacteria

El propóleos es una sustancia resinosa que las abejas Apis mellífera adultas producen para garantizar la total asepsia de la colmena. Otras especies de abejas también producen propóleos. Con el objeto de evaluar la actividad bacteriostática y bactericida in vitro de la tintura etanólica de propóleos comercial al 70 % v/v proveniente de un apiario del Estado Cojedes, Venezuela sobre bacterias enteropatógenas ATCC. Se utilizaron Salmonella entérica subsp entérica serotipo paratyphi A, Salmonella entérica subsp entérica serotipo paratyphi B Salmonella entérica subsp entérica serotipo typhi, Shigella sonnei, Shigella flexneri, Yersinia enterocolitica y Escherichia coli enterohemorrágica (O157:H7). Las cepas mencionadas se expusieron a distintas concentraciones de tintura de propóleos durante 24 horas para determinar la Concentración Mínima Inhibitoria (CMI) y la Concentración Mínima Bactericida (CMB) utilizando el método de macrodilución en tubos. Resultados: Salmonella paratyphi A fue la única bacteria con efecto inhibitorio total en agar BHI. En las demás bacterias se evidenció efecto bacteriostático parcial. Yersinia enterocolítica fue la más sensible con una CMI 4% y CMB 8 %, seguida por Shigella sonnei, Salmonella paratyphi B, Salmonella typhi y Escherichia coli (O157:H7), con CMI 8% Y CMB 11% y finalmente Shigella flexneri y Salmonella paratyphi A fueron las más resistente con CMI 11% y CMB 15%. Se demostró que la tintura de propóleos tiene efecto bacteriostático y bactericida in vitro en las cepas estudiadas y que el etanol presente como solvente no es el responsable de tal efecto.

Propolis is a resinous substance produced by adult bees Apis mellífera to ensure complete asepsis of the hive. Other species of bees also produce propolis. The aim of this study was to assess the bacteriostatic and bactericidal activity in vitro of commercial ethanolic tincture of propolis 70% v/v from an apiary in Cojedes State, Venezuela on enteropathogenic bacteria ATCC. Used Salmonella enterica subsp enterica suptype paratyphi A, Salmonella enterica subsp enterica suptype paratyphi B, Salmonella enterica subsp enterica subtype typhi, Shigella sonnei, Shigella flexneri, Yersínia enterocolitica, and Escherichia coli (O157:H7). The strains mentioned were exposed to different concentrations of propolis for 24 hours to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) using the macrodilution method in tubes. Results: S. paratyphi A was the only bacterium with a total inhibitory effect on agar BHI. In other bacteria, a partial bacteriostatic effect was observed. Y. enterocolítica was the most sensitive with a CMI 4% and CMB 8 %, followed by E. coli (O157:H7). S. typhi, S. paratyphi B and S. sonnei with CMI 8% and CMB 11% and finally S. flexneri and S. paratyphi A were the most resistant with CMI 11% and CMB 15%. Results indicate that propolis tincture has a bacteriostatic and bactericidal effect in vitro in the strains studied, and that such effect is not due to the ethanol present as solvent.