Abstract: Compounds having both anticancer and antimicrobial activity have promising therapeutic potential due to their selective cytotoxicity and their potential to reduce the occurrence of bacterial and fungal infections in immune-compromised cancer patients. In our quest to find new antimicrobial agents with potent anticancer activity, the biological potential of leaves from the three medicinal plants Centella asiatica, Warburgia salutaris and Curtisia dentata as used by Zulu traditional healers for the treatment of cancer is investigated. Extracts were assayed for antibacterial activity using the agar well diffusion and micro plate dilution assay. In addition, minimum bactericidal concentrations (MBC), lactate dehydrogenase (LDH) release assay and rhodamine 6G intake assay were used to ascertain the antibacterial activity. The cytotoxic effects of the plant extracts were determined using tetrazolium-based colorimetric (MTT) cell proliferation assay against MCF-7, human colorectal carcinoma cells (Caco-2), A549 and HeLa cancerous cell lines. The acetone extracts from Waburgia salutaris revealed noteworthy anti-proliferative effect yielding IC50 value of 34.15 μg/ml against MCF-7 cell line, while acetone extract from Curtisia dentata significantly (P ≤ 0.05) revealed promising IC50 values of 41.55, 45.13, 57.35 and 43.24 μg/ml against A549, HeLa, CaCo-2 and MCF-7 cell lines. The extracts further revealed a broad-spectrum antibacterial activity against bacterial strains used in the study. An acetone extract from W. salutaris revealed the highest zone of inhibition and the lowest minimum inhibitory concentration (MIC) of 21.0 mm and 0.16 mg/ml respectively against Staphylococcus aureus. Methanol extract from W. salutaris and ethyl acetate extract from C. dentata revealed 53% inhibition of R6G inside the cell against Staphylococcus aureus and Escherichia coli respectively in a cytosolic lactate dehydrogenase assay, suggesting that the mode of action of such extracts may be through efflux pump. Overall, the extracts had good antibacterial activity and anti-proliferative effects against selected cancerous cell lines. Given the good antibacterial activity of the extracts the plants may act as an immune booster and prevent infection in immunosuppressed cancer patients. This is further supported by the plants’ anti-proliferative potential, bacteriostatic, bactericidal properties and also their ability to block bacterial efflux pump systems.

Abstract: Objective. Lactic acid bacteria (LAB) were isolated from fermented foods, such as glutinous rice dough, corn noodle, chili sauce, potherb mustard pickles, and stinky tofu, in northeast China. LAB strains with antimicrobial activities were screened, and seven of these Lactobacillus strains were identified as L. plantarum, L. pentosus, and L. paracasei through 16S rRNA gene analysis. After the supernatant of LAB was treated with proteinase K, pepsin, and papain, their antibacterial effect almost disappeared. Most strains with antibacterial activities were highly resistant to heat (65°C–121°C), acidity (pH 2–6), and alcohol. The antimicrobial effect of most strains treated with the Tween-80 surfactant was significantly reduced, and the antibacterial property of T4 was even lost. Ammonium sulfate precipitation, PCR, and nanoLC-ESI-MS/MS results confirmed that T8 produced antibacterial substances belonging to a protein family, and its zone of inhibition against pathogens significantly increased (>13 mm). In bacterial growth inhibition experiments, the colony count of Staphylococcus aureus was up to 1015 CFU/mL in the 3 de Man, Rogosa, and Sharpe (MRS) group, and this value was more than that in the 3 S6 supernatant group (1012 CFU/mL) and the control group (1010 CFU/mL) at 12 h. This study provided a basis for the selection of antimicrobial peptides and the development and utilization of LAB.

Abstract: Plant derived medicines show significant contributions to mankind in treating infections of pathogenic bacteria. Recently plants are used in pharmaceutical industries for novel drug preparations because to ensure efficacy and safety as synthetic antibiotics are threatened for their multidrug resistance. The present study aimed at finding antibacterial potential of aqueous and ethanolic leaf extracts of Combretum album. Antibacterial activity was evaluated against seven bacterial strains by determining minimum inhibitory concentration (MIC) and zone of inhibition. Diameters of the zone of inhibition were compared with standard antibiotics. Preliminary phytochemical screening was done according to standard protocol. FTIR analysis was performed to identify the general phytochemical groups of compounds in the extract. All experiments were conducted in triplicate and values were expressed as the mean ± standard deviation. One-way analysis of variance (ANOVA) and Tukey tests were performed for statistical justification. Maximum zones of inhibition were found in case of ethanolic extracts in the following order Bacillus licheniformis (MTCC 530) > Pseudomonas aeruginosa (MTCC 2453) > Bacillus subtilis (MTCC 441) >, Pseudomonas fluorescens (MTCC 103) > Bacillus mycoides (MTCC 7343) > Escherichia coli (MTCC 739) > Pseudomonas putida (MTCC 1654) with zone of inhibition of 27.67 ± 0.33 mm diameter in B. licheniformis (MTCC 530). Qualitatively, the ethanol extract contains flavonoids, tannins and alkaloids. The results of FTIR analysis confirmed the presence of R-CH2-OH groups, aromatics, C-N stretching amine and NH stretching secondary amine. One way ANOVA and Tukey tests statistically justify the data (p ≤ 0.05). All the tested leaf extracts showed promising antibacterial activity against both gram positive and gram negative bacteria. Phytochemical screening and FTIR analysis revealed the presence of tannins, alkaloids, R-CH2-OH groups, aromatics and flavonoids in ethanolic leaf extract qualitatively and these compounds could be responsible for antibacterial property of leaf extracts of C. album.

Abstract: Background: Natural products play a significant role in human therapy. They represent a huge reservoir of bioactive chemical diversity and help in understanding the cellular pathways that are essential component of drug discovery process. Objective: This study was aimed at evaluating the antimicrobial activity of stigmasterol isolated from the stem bark of Neocarya macrophylla . Methods: Stigmasterol previously isolated from the stem bark of N. macrophylla was subjected to antimicrobial screening against methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), S. aureus, Streptococcus faecalis, Escherichia coli, Salmonella typhimurium, Pseudomonas fluorescens, Klebsiella pneumoniae, Candida albicans and Candida krusei using agar diffusion and broth dilution methods. Results: Susceptibility test results showed that the compound (100 μg/mL) inhibited the growth of all the test organisms with mean zone of inhibition range from 23 mm to 30 mm except the VRE, S. typhi and K. pneumoniae . The activity of stigmasterol was compared with that of ciprofloxacin (5 μg/mL), the standard antibacterial drug, and fluconazole (5 μg/mL), the antifungal agent. The test compound displayed a broad-spectrum of activity, and in many cases exhibited comparable antibacterial activity when compared to ciprofloxacin. Interestingly, the compound also showed antifungal activity against Candida spp., affording comparable inhibitory effect as fluconazole. The minimum inhibitory concentration (MIC) and the minimum bactericidal/fungicidal concentration (MBC/MFC) of stigmasterol range from 6.25 μg/mL to 25 μg/mL and from 12.5 μg/mL to 50 μg/mL, respectively. Conclusion: These properties suggest that the isolated stigmasterol is a potent and broad-spectrum antibacterial and antifungal agent and as such may serve as a lead compound in the development of novel antimicrobial drugs.

Abstract: Context: Silver nanoparticle (AgNP) is a potent antimicrobial that is widely used in several fields of medicine Chlorhexidine (CHX) gluconate is a well-known agent used in dentistry to eliminate oral microbial flora Aims: The aim of this study is to evaluate the efficacy of AgNPs, 2% CHX gluconate, and the combination of two solutions against endodontic pathogens such as Enterococcus faecalis, Klebsiella pneumoniae, and Candida albicans These organisms are frequently found in the root canal space and their persistence may lead to endodontic failure The synergistic effect of the two solutions has been evaluated in this study The antibiotic gentamycin was taken as the control group Settings and Design: Agar well diffusion method was used and minimum inhibitory concentration of AgNP was found to be 15 μg/mL AgNPs were synthesized from the aqueous plant extract of Cassia roxburghii The combination of CHX-AgNP solution was stirred together by a glass rod The values were tabulated and subjected to statistical analysis using the SPSS software version 20 One-way ANOVA test was used to compare within the groups and between groups The level of significance was set at 5% Results: CHX-AgNP combined solution exhibited the highest efficacy in comparison to these solutions used alone They showed the highest efficacy against C albicans among the three organisms tested Conclusion: The present study demonstrates the antimicrobial efficacy of a novel mixture of CHX-AgNP solution, and it may be developed as a promising antimicrobial agent against endodontic flora

Abstract: Background. External infections involving the skin and wound are the most frequent complications affecting humans and animals. Medicinal plants play great roles in the treatment of skin and wound infections. This study was aimed to evaluate the in vitro antibacterial activity of crude methanolic extracts of nine medicinal plants. Methods. Agar well diffusion and broth dilution methods were used to determine the antibacterial activity of nine Ethiopian plants against four bacterial species including Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Klebsiella pneumoniae. Results. Among the tested plants, seven (Cissus quadrangularis, Commelina benghalensis, Euphorbia heterophylla, Euphorbia prostrate, Momordica schimperiana, Trianthema spp., and Solanum incanum) were found to exhibit considerable antibacterial activity against at least one of the test bacteria. The extracts of C. quadrangularis, E. heterophylla, and E. prostrata had a wide spectrum of antibacterial activities against test bacterial strains while the extracts of Grewia villosa and Schinus molle did not show any inhibitory activity. Clinical isolate and laboratory strain of S. aureus showed the highest susceptibility to highest concentration (780 mg/mL) of E. prostrata with a zone of inhibition of 21.0mm and 22.3mm, respectively. Conclusion. This study indicates clear evidence supporting the traditional use of seven plants in treating skin and wound infections related to bacteria.

Abstract: This study presents antimicrobial properties of Uvaria chamae roots, commonly used for the treatment of various infections in south Benin. Their constituents were extracted and then fractionated in order to isolate the active ingredients. Antimicrobial susceptibility tests were performed against several multidrug-resistant bacteria using the Mueller Hilton well agar diffusion method. Results showed that ethanol extracts were highly active against Gram-positive cocci. This activity was more extensive than that measured from conventional broad-spectrum antibiotics. Indeed, vancomycin-resistant enterococcus (VRE) and methicillin-resistant Staphylococcus aureus (MRSA) strains were all sensitive to this root extract. The aim of this study was to link the antimicrobial activity of the root to chemical structures. The ion mobility mass spectrometry analysis revealed for the first time the presence of ten chalcone and dihydrochalcone structures responsible for the antimicrobial activity of Uvaria chamae ethanol extracts. Two structures were described here for the first time in these roots. These findings confirm and justify the medical properties of these roots used as a traditional medicine.

Abstract: Both diarrhea in calves and mastitis in cows limit cattle production. The bacteria involved in these diseases have shown multi-resistance to antimicrobials, however plant metabolites therefore can provide an alternative method of control. This study selected and characterized Cerrado plant extracts showing inhibitory effects against Escherichia coli and Staphylococcus spp. from cattle. Thirteen leaf extracts were initially screened and diameters of inhibition zones produced against the pathogens were recorded using an agar disk diffusion method. Total condensed tannin contents were determined and antibacterial activities were analyzed after tannin removal from the five selected extracts. The minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) were evaluated by macro-dilution antimicrobial susceptibility tests, and the extracts were characterized by high performance liquid chromatography. Inter- and intra-specific bacterial variations in the susceptibility to the extracts were detected. The aqueous extract (AE) from Caryocar brasiliense Cambess. leaves produced larger inhibition zones against E. coli strains than did other selected extracts. However, the AE from Schinopsis brasiliensis was the most effective against Staphylococcus spp. strains (P < 0.001). The MIC of ethanolic extracts (EE) from C. brasiliense (0.27 mg/mL) and S. brasiliensis (0.17 mg/mL) were lower than those of other extracts. The MIC and MBC of the Annona crassiflora EE were 6.24 mg/mL for all bacteria. Flavonoids were the main metabolites detected in the A. crassiflora EE as well as in the AE and EE from C. brasiliense, while tannins were the main metabolites in the S. brasiliensis leaf extracts. The AE from C. brasiliense was more effective against Gram-negative bacteria, while the AE from S. brasiliensis was more effective against Gram-positive bacteria. A. crassiflora EE and S. brasiliensis extracts are potent bactericide. After removal of the tannins, no antimicrobial effects were observed, indicating that these metabolites are the main active antibacterial components.

Abstract: In many developing countries a large proportion of the population relies on traditional practitioner of medicinal plants in order to meet health care need. Garlic is one of the herbs that used by traditional practitioners for preparation of herbals medicine. Emergence of drug resistance is obvious and global confront. Seeking for other antibiotics which are new, natural, plant based. Garlic is classified as member of family Alliaceae. Allicin is one of the active principal of freshly crushed garlic homogenates, have variety of antimicrobial activities. This study was conducted to evaluate the anti-bacterial effect of garlic against standard isolates of S. aureus and E. coli kindly obtained from EHNRI. Four different solvents having different polarity were used to extract the bioactive compound from garlic. The Antibacterial activity of the crude extracts of garlic was evaluated against Standard isolates of S. aureus and E. coli by an agar diffusion method. The trial was done in triplicates. A Factorial Design with three factors was used. The treatment means were compared by a Student’s t- test with least significant difference (LSD) at 5% (P=0.05) and the data analysis was performed using mini tab statistical software package. In this experiment the non-polar chloroform had higher inhibition zone. The highest yield potential was obtained from water followed by ethanol, chloroform and petroleum ether respectively. E. coli were so susceptible than S. aureus to the extracts. Garlic could be used as effective antibacterial agent for human pathogenic bacteria.

Abstract: The aim of the present study is to determine the antibacterial and antibiofilm activity of alkaloids and flavonoids isolated from Curcuma species. To compare the potential of different constituents isolated from Curcuma species, the rhizomes of three species of Curcuma i.e. C. longa (Turmeric), C. caesia (Black turmeric) and C. aromatica (Wild turmeric) were processed and analyzed. Flavonoids and alkaloids were extracted using methanol and acetic acid, respectively. Antibiofilm activity of alkaloids and flavonoids was determined using Gram-positive bacteria Staphylococcus aureus and Bacillus subtilis, which have unique properties to made biofilm very fast in solid surface as well as resist too many antibiotics. Results showed positive correlation with the concentration of alkaloids and flavonoids in both bacteria. The dispersal activity was further confirmed by the microscopic examination. In all the tests standard curcumin and camphor were used as a positive control. The flavonoid extract of C. aromatica showed pronounced zone of inhibition and antibiofilm activity against S. aureus in comparison to other two Curcuma species. In addition, alkaloid extract of C. aromatica exhibited maximum biofilm dispersal 89.22 ± 3.42% and antibiofilm activity 92.16 ± 0.76% against B. subtilis. C. aromatica which have a unique mechanism to inhibit the growth of bacteria in comparison to well explored C. longa.

Abstract: Extraction, thin layer chromatography and gas chromatography–mass spectrometry of Solena amplexicaulis (Lam.) Gandhi, commonly known as creeping cucumber, (Cucurbitaceae) leaves revealed 21 long-chain primary alcohols, and 100 g leaves indicated presence of 3651.59 ± 327.18 SE µg long-chain primary alcohols. 1-Heptadecanol and 1-triacontanol were the predominant and least abundant primary alcohols, representing for 780.44 ± 42.59 and 3.28 ± 0.55 SE μg, respectively. Antibacterial property of the complete synthetic blend (0.1%), comparable to long-chain alcohols as detected by GC-FID of 100 g S. amplexicaulis leaf extracts was evaluated on the pathogenic bacteria Salmonella gallinarum by agar well diffusion method, and exhibited 20.4, 26.7 and 38.2 mm zone of inhibition at 25, 50 and 100 μl doses, respectively. One hundred µl dose of 6 individual pure synthetic compounds, 1-tridecanol, 1-pentadecanol, 1-heptadecanol, 1-nonadecanol, 1-eicosanol and 1-tricosanol comparable to the amounts present in 0.1% solution of pure isolated alcohols from S. amplexicaulis leaves displayed 16.2, 17.7, 18.6, 22.8, 15.8 and 14.5 mm zone of inhibition against this bacterium, respectively. Hundred µl dose from a synthetic blend of above 6 compounds (comparable to the proportions as present in 0.1% solution of pure isolated alcohols from 100 g S. amplexicaulis leaves) exhibited 38.1 mm zone of inhibition against this bacterium. Furthermore, 100 μl dose from a mixture (1:1) comprising of chloramphenicol (1 µg/ml) and a synthetic blend of above 6 compounds displayed 38.8 mm inhibition zone against S. gallinarum, and hence, this combination might be used against this pathogenic bacteria.

Abstract: The study aimed to evaluate the antimicrobial activity of medicinal plant extracts against the bacterial pathogens prominent in dental caries. A total of 20 plant species (herbs, shrubs and trees) belonging to 18 genera and 15 families were documented for dental caries. Antimicrobial activity of solvent extracts and essential oil from plants were determined by zone of inhibition on the growth of Streptococcus mutans (MTCC 497) and Lactobacillus acidophilus (MTCC 10307) using the agar well diffusion method. The results of in vitro antimicrobial assay prove that methanol is more successful in the extraction of phytochemicals from plant samples than aqueous solvent, as methanol extracts show higher antimicrobial activity than aqueous extracts against both the test pathogens. Methanol extracts of Nigella sativa, Psidium guajava and Syzygium aromaticum were the most effective among all 20 plant samples and have potent inhibitory activity against both dental caries pathogens with minimum inhibitory concentration of 0.2 mg mL− 1. N. sativa seed methanol extract was more effective with 22.3 mm zone of inhibition at 0.2 mg mL− 1 against S. mutans (MTCC 497), while L. acidophilus (MTCC 10307) was more sensitive to S. aromaticum bud methanol extract at 11.3 mm zone of inhibition at concentration 0.1 mg mL− 1. Essential oil extracted from plants also possesses strong antimicrobial activity for both test pathogens, with a minimum inhibitory concentration range of 0.05–0.16 mg mL− 1. Syzygium aromaticum bud essential oil at 0.05 mg mL− 1 was most active against S. mutans (MTCC 497). Plant extracts viewing antimicrobial activity with minimum inhibitory concentration show the efficacy of the plant products that could be considered as a good indicator of prospective plants for discovering new antimicrobial agents against dental caries pathogens. The findings of this study provide a lead to further polyherbal formulations for the treatment of dental caries malaise.

Abstract: Objectives: This study was conducted to assess the prevalence and characterization of Staphylococcus aureus from chicken and quail eggshells and to study the antibiogram of the isolates. Materials and methods: A total of 300 eggs (220 chicken eggs and 80 quail eggs) were collected from different retail shops and farms in Mymensingh district. Swabs taken from the egg surfaces were cultured on Mannitol Salt Agar for the isolation of S. aureus. Polymerase chain reaction was conducted for confirmatory identification of the bacterial species targeting nuc gene, followed by confirmation of methicillin-resistant S. aureus by targeting the mecA gene. Antibiotic sensitivity test of the isolated bacteria was done against commonly used antibiotics by the disk diffusion method. Results: The prevalence of Staphylococcus spp. and S. aureus in the chicken eggshell surface was 20.45% and 10.45%, respectively. Similarly, the prevalence of Staphylococcus spp. and S. aureus in quail eggshell surface was 16.25% and 5%, respectively. Overall, 27 isolates were identified as S. aureus, of which 23 were from the chicken eggshell surface and four from quail eggshell surface. Among the seven isolates tested, overall four (57.14%) were positive for the nuc gene. On the other hand, the mecA gene could be detected in three (50%) S. aureus out of six oxacillin resistant isolates. The antibiogram study indicated that most of the isolates were resistant to the antibiotics under β-lactam group. Conclusion: The present study concludes that chicken and quail egg surface harbor multidrugresistant bacteria which may cause public health hazards, if these antibiotic-resistant bacteria are transferred to a human.

Abstract: The present study assessed the in vitro antibacterial and antibiofilm potential of hexane (ASHE) and dichloromethane (ASDE) extracts of Allium stipitatum (Persian shallot) against planktonic cells and biofilm structures of clinically significant antibiotic resistant pathogens, with a special emphasis on methicillin-sensitive Staphylococcus aureus (MSSA), methicillin-resistant S. aureus (MRSA), and emerging pathogens, Acinetobacter baumannii and Stenotrophomonas maltophilia. Antibacterial activities were determined through disk diffusion, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), time-kill kinetics, and electron microscopy. Antibiofilm activity was assessed by XTT [2,3-bis(2-methoxy-4-nitro-5-sulfo-phenyl)-2H-tetrazolium-5-carboxanilide] reduction assay and by confocal laser scanning microscopy (CLSM). The zone of inhibition ranged from 13 to 33 mm, while the MICs and MBCs ranged from 16 to 1024 μg mL−1. Both ASHE and ASDE completely eradicated overnight cultures of the test microorganisms, including antibiotic resistant strains. Time-kill studies showed that the extracts were strongly bactericidal against planktonic cultures of S. aureus, MRSA, Acinetobacter baumannii, and S. maltophilia as early as 4 hours postinoculation (hpi). ASHE and ASDE were shown to inhibit preformed biofilms of the four biofilm phenotypes tested. Our results demonstrate the potential therapeutic application of ASHE and ASDE to inhibit the growth of gram-positive and gram-negative biofilms of clinical significance and warrant further investigation of the potential of A. stipitatum bulbs against biofilm-related drug resistance.

Abstract: There is a need to discover new therapeutic substances due to the emergence of deadly infectious diseases and various antibiotic resistance. We focused on the larvae that are utilized as a medical insect for the treatment of skin damage in Europe and America. This study was to investigate the pharmacological activities of novel antibacterial peptides isolated from Hermetia illucens larvae against the Klebsiella pneumoniae and Shigella dysenteriae. The larvae were immunized by probiotics (Lactobacillus casei) for 24 h. The hemolymph from the immunized larvae was fractionated through reverse-phase chromatography. Peptides were purified using HPLC and the coomassie blue staining, and identified using Nano-LC-ESI-MS/MS system. Antibacterial activities of the peptides were evaluated by turbidometric assay, liquid broth dilution assay, resazurin assay, and agar disk diffusion method. The minimum inhibitory concentrations (MICs) of the peptides were measured as 150 μg/mL through the turbidometric, liquid broth dilution, and resazurin assays. The peptides effectively inhibited their growth/proliferation as well as the survival rate of the tested bacteria. Furthermore, the immunized larvae exhibited overexpression of the peptides compared to non-immunized larvae. These results demonstrate that the peptides induced by H. illucens exert strong antibacterial activity against Gram-negative bacteria. The results suggest that the activation of the humoral immunity induced by immunization functioned to enhance the production of antibacterial peptides from the insect and their antibacterial properties. This study indicates the potential of the peptides produced from larvae as antibacterial peptide substance for the development of novel antibacterial drugs.

Abstract: The prehistoric interaction of plants and human is being strengthened by the remarkable use of plants as remedy against diseases. Cucumis sativus L. is extensively cultivated globally including Pakistan. The present study was carried out to find the antioxidant, antimicrobial and phytochemical analysis of Cucumis sativus seed extract. Phytochemical analysis of ethanolic extract revealed the presence of flavonoids, terpenoids, tannins, cardiac glycoside, phenols and carbohydrates. 2,2-diphenyl-1-picrylhydrazyl (DPPH) method was used for antioxidant activity. Crude ethanolic extract showed maximum DPPH scavenging activity of 46.05±1.23 at 500µg/ml, while ascorbic acid showed 92.5%. For Antimicrobial activity against selected bacteria and fungi by agar well diffusion method was used. In the antibacterial activity, crude ethanolic extract was most active against Staphylococcus aureus (21.5mm) and less against Shigella flexneri (17.0mm). The n-haxane fraction was highly active against Salmonella typhi (26mm), DCM against E. coli (16.25mm) and Salmonella typhi showed 16.0mm inhibition with ethyl acetate. Crude extract of ethanol was tested against Alternaria, Acremonium, Verticellium, Pythium and Tricoderma sps. Alternaria showed low zone of inhibition (08mm) while the rest of fungi were highly susceptible with zone of inhibition 15mm, 14mm, 17mm and 15mm respectively. The Pythium spp. was highly susceptible to n-haxane fraction (20.00mm), Acremonium to DCM fraction (20.00mm) and to ethyl acetate (16.00 mm). The results showed significant antimicrobial and antioxidant activity which might be because of flavonoids, terpenoids, tannins and phenols in there, suggesting that C. sativus should be used as an active nutrition to control microbial infections leading to chronic diseases. Keywords: Antimicrobial activity; Antioxidant activity; Cucumis sativus L.; Phytochemical analysis http://dx.doi.org/10.19045/bspab.2018.700202

Abstract: Considering antimicrobial resistance problem, marine microorganisms with the bioactivity against multi-drug resistant (MDR) pathogens have attracted many scientific interests. To address this issue, a total of 21 marine actinomycetes isolated from the Caspian Sea have been screened out. Primary screening via cross-streak method revealed that 3 strains: MN2, MN39, and MN40 produce antimicrobial agents with wide spectrum activity. In the second step, the potent strains were characterized morphologically, and then identified genetically using 16S rRNA analysis. After that, the bioactivity of the ethyl acetate extracts of liquid culture against some MDR bacteria has been studied using disc diffusion method. Finally, the exoenzymatic activity of the strains, and the anti-vibrio activity of the extracts have been evaluated. The nucleotide sequence of the 16S rRNA gene (1.5 kb) showed that the potent strains belong to the genus Streptomyces. The results of disk diffusion method indicated that among the 3 potent isolates, MN39 and MN2 produce biomolecules with antibacterial activity against MDR bacteria specially methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus (VRE). In addition, potent strains showed remarkable anti-vibrio activity as well as extracellular enzyme production including amylase and protease. The results of this study revealed that the marine actinomycetes isolated from the sediments of Caspian Sea produce biomolecules effective against MDR bacteria, and suggested that these strains deserve to be studied as potential probiotics due to their anti-vibrio activity besides exoenzyme production.

Abstract: Multi-drug resistant uropathogens are responsible for urinary tract infections. The antibacterial activity of seven essential oils, oregano, thyme, clove, arborvitae, cassia, lemongrass, tea tree) was investigated by agar diffusion method, followed by determination of minimum inhibitory (MIC) and bactericidal (MBC) concentrations against five multidrug resistant isolates namely Pseudomonas aeruginosa, Escherichia coli, Enterobacter cloaceae, Morganella morganii, Proteus mirabilis. Oregano, thyme, cassia had antibacterial activity with inhibition zones ranging 25–39 mm; clove, arborvitae, tea tree and lemongrass 12–15 mm. The essential oils showed antibacterial activities with MICs ranged from 0.005% (w/v) to 0.5% (w/v). Thyme had the same MIC and MBC on all strains. The effects of the vapors of the essential oils were also tested by placing the oils on the underside of the Petri dish lid. Thyme, oregano and cassia essential oils strongly inhibited the growth of the clinical strains of bacteria tested in vapor phase. This study demonstrates the potential of investigated essential oils as natural alternatives for further application in hospital therapies in order to retard or inhibit the bacterial growth. For the first time antibacterial effects of essential oils (clove, arborvitae, tea tree, lemongrass, and cassia) were evaluated against Enterobacter cloaceae and Morganella morganii clinical isolates.

Abstract: Background and Objective: Centella asiatica belonging to family umbelliferae popularly known as pegagan, is very useful medicinal plant as an antimicrobial. However, the results of the study comparing anti-microbial activities of leaf and root of C. asiatica have not been properly documented. This paper reported on a research on the antimicrobial effect of leaf and root of C. asiatica ethanol, aqueous and chloroform extracts against representative micro-organism. Materials and Methods: The ethanol, aqueous and chloroform extracts of leaf and root of C. asiatica against six bacteria namely, Escherichia coli, Staphylococcus aureus, Staphylococcus albus, Streptococcus pyogenes, Psedomonas aeruginosa, Sreptococcus pneumonia and three fungi: Aspergillus niger, Aspergillus flavus, Microsporium boulardii and one yeast Candida albicans were determined using agar well diffusion and paper disk methods. Results: The results revealed that ethanol was the best extractive solvent for anti-microbial properties of leaf and root of C. asiatica followed in order by chloroform and aqueous. The ethanol extracts C. asiatica root gave the widest zone of inhibition against bacteria using agar well diffusion and the disc plate method. The growth of six bacterial isolates were inhibited by the three extracts except P. aeruginosa and S. pyogenes. Similarly, the growth of three test fungi were inhibited by ethanol and chloroform extracts while the aqueous extract was the least effective on the test fungi. The best antifungal activity was recorded in ethanol extract of C. asiatica root. The minimum inhibitory concentration (MIC) for the ethanol extract was between 5.0 and 20.0 mg mLG1 for fungi. Conclusion: This study revealed that the C. asiatica root demonstrated strong inhibitory effect on the test organisms than C. asiatica leaf. The results therefore established a good support for the use of C. asiatica in traditional medicine.

Abstract: In the present study, a novel eco-friendly production of silk fabrics dyed with different natural dye bath concentrations (40, 80, 120, 160, 200 and 240 g/l) extracted from neem (Azadirachta indica) leaves was developed. The surface morphology of the fabrics was examined by scanning electron microscopy (SEM) and Fourier-transform infrared (FTIR) spectroscopy to characterize the chemical structure of the fabrics. The SEM images of the undyed fabric show that the fabric was tightly woven with little porosity between the fibres with dozens of silk threads in orthogonal directions. By increasing the neem concentration, a scale of fine particles grew on the surface of the silk fabrics with little macroscopical defects was demonstrated. The fiber diameters and tightness between filaments were significantly increased. The FTIR displayed that, neem dye does not change the characteristic peaks of the silk fabrics. Also, the evaluation of the antimicrobial activity of the undyed and neem dyed silk fabrics was monitored for Gram positive and Gram negative bacteria in addition to yeasts and fungi by using the agar diffusion method. The comparison between the different dye bath concentrations was based on the inhibition zones obtained after incubation. The antimicrobial activity in leaf extract of neem was estimated in Staphylococcus aureus, Bacillus subtilis and Lactobacillus cereus (Gram positive bacteria); Escherichia coli (Gram negative bacteria); Candida albicans and Candida tropicalis (yeasts); and Aspergillus niger and Fusarium solani (fungi). The results emphasized that, the highest neem dye bath concentration (240 g/l) was found to display good inhibitory effect against the Gram positive and reasonable activity against the Gram negative bacteria. Furthermore, the different dye bath concentrations possess no activities against yeast and fungi. In conclusion, the data reveal that the increase of neem dye concentration does not damage the silk fabric; however, it improves its antimicrobial activity by incorporating with antimicrobial agent. The current study highlighted that using neem leaves had beneficial effect in controlling the pathogenic microbial organisms.

Abstract: The antioxidant and antibacterial characters for two types of locally growing guava (Psidium guajava L.) cultivars form two cities, Taiz and Ibb Yemeni cultivars were evaluated. Antioxidant properties were conducted using ABTS, phosphomolybdenum complex and DPPH assays. The antibacterial activity was evaluated using agar diffusion method against seven human-pathogenic bacteria. The results indicated that methanol extracts of guava's peel and flesh exhibited excellent antioxidant activities. The concentration of antioxidant compounds in the guava fruit cultivars revealed antioxidant activity. High concentration of peroxidase and low polyphenol oxidase were observed in the guava extract as antioxidant enzymes. The antibacterial properties of guava extracts showed differences in killing kinetics compared to human-pathogenic bacteria. The antibacterial properties of the red (Anaa) peel crude extracts against seven pathogenic bacteria indicated antibacterial activity. The obtained data indicated that red (Anaa) has better total phenolic, scavenging, and antimicrobial activity than white (Aldabab) cultivar.

Abstract: Background. Banknotes are one of the most exchangeable items in communities and always subject to contamination by pathogenic bacteria and hence could serve as vehicle for transmission of infectious diseases. This study was conducted to assess the prevalence of contamination by pathogenic bacteria in Sudanese banknotes, determine the susceptibility of the isolated organisms towards commonly used antibiotics, and detect some antibiotic resistance genes. Methods. This study was carried out using 135 samples of Sudanese banknotes of five different denominations (2, 5, 10, 20, and 50 Sudanese pounds), which were collected randomly from hospitals, food sellers, and transporters in all three districts of Khartoum, Bahri, and Omdurman. Bacterial prevalence was determined using culture-based techniques, and their sensitivity patterns were determined using the Kirby–Bauer disk diffusion method. Genotypic identification was carried out using PCR and 16S rDNA sequencing. Antibiotic resistance genes of some isolates were detected using PCR technique. Results. All Sudanese banknotes were found to be contaminated with pathogenic bacteria. Klebsiella pneumoniae was found to be the most frequent isolate (23%), whereas Bacillus mycoides (15%) was the most abundant Gram-positive isolate. There was a significant relationship between the number of isolates and the banknote denomination with value <0.05 (the lower denomination showed higher contamination level). Our study has isolated bacteria that are resistant to penicillins and cephalosporins. Multidrug-resistant strains harboring resistant genes (mecA, blaCTX-M, and blaTEM) were also detected. Conclusion. All studied Sudanese banknotes were contaminated with pathogenic bacteria, including multidrug-resistant strains, and may play a significant role in the transmission of bacterial infections.

Abstract: Objectives: To evaluate the antimicrobial activity of medicinal plants against human pathogenic bacteria and perform Minimum Inhibitory Concentration (MIC) of plants extracts. Methods: Rhizome of Curcuma longa, dried buds of Synzygium aromaticum, seeds of Zanthoxylum armatum and leaves of Elaeocarpus ganitrus, Psidium guajava, Azadirachta indica, and Artemisia vulgaris were collected from hilly regions of Nepal. The plant parts were air-dried at room temperature for several days and grinded to powder form. The ethanolic extracts of medicinal plants were prepared by using the percolation process of extraction using separating funnel and tested against human pathogenic bacteria by disc diffusion method. Then, Minimum Inhibitory Concentration (MIC) of the plant extracts were performed. Results: All plants extracts exhibited antibacterial properties against bacteria under study. However, extract from S. aromaticum (Clove), P. guajava (Guava) and E. ganitrus (Rudraksh) leaves showed most promising result against Staphylococcus aureus with zone of inhibition of 14mm, 16mm and 16 mm respectively. Likewise, S. aromaticum (Clove), C. longa (Turmeric) and P. guajava (Guava) showed good antibacterial activity against Escherichia coli with zone of inhibition of 11mm, 11mm and 10mm respectively. A. vulgaris (Titepati) and A. indica (Neem leaves) showed promising activity against Pseudomonas aeruginosa with zone of inhibition of 11mm. Z. armatum (Timur) showed good result against E. coli with zone of inhibition 10mm. MIC values of ethanolic extracts of S. aromaticum and E. ganitrus were found to be at the range of 12.5-25mg/ml. Conclusion: This study has helped to understand the use of these plants as traditional medicine in an economic and safe alternative to treat infectious diseases.

Abstract: Listeria monocytogenes is among the most important foodborne pathogens. It may enter food-processing environments through raw materials, handlers or equipment and may persist due to ineffective cleaning or sanitation. The bacterium can be isolated from both frozen vegetables and fresh food substances. This study aimed to estimate the prevalence of L. monocytogenes in spices and frozen vegetables and screen for some virulence factors and drug-resistance determinants of the isolated bacteria. First, conventional microbiological methods were used for the isolation and identification of bacteria. Next, the identity of isolated bacteria was confirmed by molecular techniques, and the virulence genes iap and hlyA were identified by real-time polymerase chain reaction (PCR). The hemolytic activity of the isolates was assessed by cultivation on sheep blood agar. Furthermore, the antimicrobial susceptibility of confirmed L. monocytogenes isolates was tested by the disk diffusion method against 10 antibiotics. Out of 331 vegetable samples, 47 isolates were confirmed to contain L. monocytogenes, whereas none of 40 spice samples tested positive. All isolates were positive for iap and hlyA genes. Susceptibility testing indicated that all isolates were sensitive to trimethoprim/ sulfamethoxazole, but only 36% were sensitive to penicillin G, while 100% and 70% showed intermediate resistance to chloramphenicol and erythromycin, respectively. All tested isolates were resistant to amoxicillin, gentamicin and norfloxacin; on the other hand, 90, 86 and 84% of the tested strains were resistant to ciprofloxacin, ceftazidime/clavulanic acid and amikacin, respectively. In summary, L. monocytogenes isolates disseminated in frozen vegetable samples from the Egyptian market were highly virulent, entirely multiple-drug resistant and were enriched in iron-containing vegetables. Since L. monocytogenes is primarily pathogenic to humans and causes a life-threatening disease, there is a potential infection risk for people who usually deal with frozen vegetables before cooking. Hence, surveillance to L. monocytogenes in frozen products, together with implementation of tight measures would be valuable in preventing listeriosis, and are highly recommended. Key words: Listeria monocytogenes, virulence gene, antibiotic resistance.

Abstract: The use of antibiotics has unleashed high bacterial resistance. This outcome triggered the urgent need for effective new antibacterial agents to treat infectious diseases. A promising source for the production of antibiotics and several other bioactive substances are endophytic fungi. These microorganisms inhabit in and bring benefits to living plant tissues. Thus, the aim of this paper was to know the endophytic fungi associated with Oryctanthus alveolatus (mistletoe) and assess their potential to inhibit pathogenic bacteria. A total of 86 endophytic fungi were isolated from the stems and leaves of O. alveolatus. Of these fungi, 29 were selected for the assessment of antimicrobial activity. The antimicrobial activity of the obtained extracts was evaluated using the agar diffusion method towards two Gram-positive pathogenic bacteria (Staphylococcus aureus and Staphylococcus epidermidis) and two Gram-negative bacteria (Pseudomonas aeruginosa and Escherichia coli). The extracts were tested at concentrations of 200, 500, 700, 800, 900 and 1000 µg.mL-1. The antimicrobial test showed that two (COA 009 and 014) of the 29 extracts inhibited bacterial growth of at least one of the strains each, from both Gram-positive and Gram-negative bacteria. The extracts with the inhibitory activity were derived from the fungi Curvularia sp. (COA 009) and Diaporthe sp. (COA 014). Key words: Gram-positive and Gram-negative bacteria, microorganisms, Loranthaceae.

Abstract: In Ghana there are concerns that antibiotics may be used inappropriately to boost fish production, though no study has investigated this problem. To provide preliminary insights into public health aspects of the problem, we investigated the occurrence of antibiotic residues and antibiotic-resistant bacteria in Nile tilapia (Oreochromis niloticus), a fish commonly cultivated and consumed in Ghana. Two hundred Nile Tilapia fish were randomly sampled from four major markets in Accra, the capital city of Ghana. One hundred samples were screened for antibiotic residues using a microbial inhibition plate test that detects sixteen different antibiotics commonly used in animal husbandry and aquaculture. The other 100 samples were cultured for bacteria using direct culture methods, and the isolates were tested against seven antibiotics by the Kirby Bauer method. The overall prevalence of antibiotic residues in the fish samples was 7%. Bacteria that were isolated from the fish samples were Shigella sonnei (10%), Enterobacter cloacae (7%), Escherichia coli (6%), Salmonella Typhi (3%), Klebsiella pneumoniae (2%), and Proteus mirabilis (2%). All bacteria isolated were susceptible to gentamicin and ciprofloxacin but resistant to ampicillin. Multi-drug resistance (ie resistance to three or more different classes of antibiotics) occurred in 86.7% of the isolates. Nile Tilapia sold in Accra is a source of multi-drug resistant bacteria. Consumption of the fish can also lead to significant exposure to antibiotic residues.

Abstract: Background: Recently, nanotechnology has been demonstrated to be a promising application to overcome the problem of antibiotic resistance. In the present study, we aimed to determine the antibacterial activity of copper oxide nanoparticles (CuO NPs) on several multiple-drug resistant (MDR) uropathogenic strains. Methods: This in vitro case-control study was performed on 4 uropathogenic bacteria including Staphylococcus aureus, Enterococcus faecalis, Escherichia coli and Pseudomonas aeruginosa. The antibacterial property was evaluated by well diffusion method at different concentrations of CuO NPs. Results: Overall, NPs concentration of 10, 25 and 50 µg/mL showed the remarkable antibacterial activity. A lower effect was seen against S. aureus strains. CuO NPs exhibited maximum bacterial growth inhibition against E. faecalis strains. In most of the cases, the zone of inhibition in 50 µg/mL concentration was closest to control positive antibiotics. Conclusion: In summary, CuO NPs as an alternative to conventional antibiotics that are currently used showed dose-dependent on antibacterial activity against different uropathogens, specificity towards pathogenic Gram-positive bacteria. This promising antibacterial activity of CuO NPs suggesting the development of NPs coatings on the different surface of biomedical materials for applications in different antimicrobial control systems.