Evaluation and Risk Management by Using Ocimum bacillicum Against Waterborne Pathogens

Food and medicinal plants have been used for centuries against human diseases. The methanolic and aqueous extracts of different parts of Ocimum bacillicum Lam. (Niazboo or Sweet basil) of family Lamiaceae were investigated in vitro for their antibacterial properties against waterborne pathogens. The antibacterial properties of different parts of Ocimum bacillicum samples were assessed against Gram positive and Gram negative bacteria, which were isolated from water samples and identified by the API 20E method. The extracts from leaves and seeds of Ocimum bacillicum showed more antibacterial activities against Staphylococcus aureus, Pseudomonas aeruginosa, and E. coli at 37°C than those obtained from shoots, roots, and buds. The lowest minimum inhibitory concentrations and minimum bactericidal concentrations were observed for leaves and seeds as compared to other parts of the plant. No activity of alum was observed against the tested bacterial strains. The seeds of Ocimum bacillicum were associated with higher coagulation activity in comparison to other parts of the plant and were comparable with alum. These results suggest that parts of a plant offer a potential for antimicrobial treatment of drinking water, but needs further exploration.     

Assessment of Antibacterial Activity of Solanum surrattense Against Waterborne Pathogens Isolated from Surface Drinking Water of the Potohar Region in Pakistan

People dwelling in different cities of the Potohar region, Pakistan, are mostly dependent on surface water for drinking and domestic use. In an attempt to make available potable, safe water, filtration plants were constructed along with dams in the Potohar region. Water samples from these filtration plants were collected and analyzed for total and faecal coliform bacteria as well as for total viable count. Results showed that bacterial indicators of faecal contamination were numerous and significantly greater than World Health Organization recommended guidelines. Accordingly, antibacterial activity of methanolic and aqueous extracts of different parts of Solanum surrattense were assessed in vitro against waterborne pathogens. Fruits exhibited more antibacterial activities at incubation at 37°C than shoots and roots, which showed lowest Minimum Inhibitory Concentration (MIC) and zones of inhibition. These results suggest that plants offer a great potential for purification of drinking water that needs to be explored further because fruit extract of the aforementioned plant can be of practical use against waterborne pathogens.     

Antibacterial spectrum and cytotoxic activities of serrulatane compounds from the Australian medicinal plant Eremophila neglecta

Aims: To determine the antibacterial spectrum and cytotoxic activities of serrulatane compounds from the Australian plant Eremophila neglecta. Methods and Results: Antimicrobial activities of serrulatane compounds 8,19‐dihydroxyserrulat‐14‐ene ( 1 ) and 8‐hydroxyserrulat‐14‐en‐19‐oic acid ( 2 ) were tested against Gram‐negative and Gram‐positive bacteria including human and veterinary pathogens and some multidrug‐resistant isolates. Minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) of the compounds were determined by broth microdilution assay. Both compounds exhibited antibacterial activity against all Gram‐positive test strains. They showed antimycobacterial activity against isolates of Mycobacterium fortuitum and Mycobacterium chelonae. Of the five Gram‐negative bacteria tested, only Moraxella catarrhalis showed susceptibility to the compounds. Cytotoxic activities were tested in the Vero cell line. Compound 1 showed more activity than 2 in both antibacterial and cytotoxicity assays with cytotoxicity at concentrations similar to the MBC. Conclusions: Serrulatane compounds showed significant activity against medically important bacteria, with 1 exhibiting stronger antibacterial activity. However, they also displayed toxicity to mammalian cells. Significance and Impact of the Study: Serrulatanes are of interest as novel antibacterial compounds for use in biomedical applications; this study reports data obtained with a range of bacterial strains and mammalian cells, essential for assessing the capabilities and limitations of potential applicability of these compounds.     

Evaluation of antioxidant and antibacterial activity of methanolic extracts of Gentiana kurroo royle

In this study our objective was to evaluate the antioxidant and antimicrobial activity of methanolic extracts of leaves and roots of Gentiana kurroo. The antioxidant activities of the extracts were examined using different biochemical assays namely diphenylpicrylhydrazyl (DPPH), nitroblue tetrazolium (NBT) and ferric reducing power (FRAP). In all the assays, root extract exhibited stronger antioxidant activity than that of leaves. The antibacterial activity of the extracts was also evaluated and MIC values were calculated by broth dilution method. Although, the extracts prevented the growth of both Gram positive and Gram negative bacteria, the MIC values of methanolic extract of the leaves were higher than those of the root extract. The antibacterial and antioxidant activity of the extracts was found to be positively associated with the total phenolic and flavonoid content of the extracts.     

Broad-spectrum antibacterial and antifungal properties of certain traditionally used Indian medicinal plants

Ethanolic extracts of 22 traditionally used Indian medicinal plants were studied for their antimicrobial activity against seven bacteria (Staphylococcus aureus, Salmonella typhimurium, S. paratyphi, S. typhi, E. coli, Shigella dysenteriae and Pseudomonas aeruginosa) and five filamentous fungi (Aspergillus niger, Alternaria alternata, Fusarium chlamydosporum, Rhizoctonia bataticola and Trichoderma viride) and a yeast Candida albicans of clinical origin. Of these, 16 plant extracts showed varied level of antibacterial activity against one or more test bacteria. Similarly antifungal and anticandidal activity was detected among 17 and 9 plant extracts respectively. Broad-spectrum antimicrobial activity (both antibacterial and antifungal) was detected among crude extracts of Bryophyllum pinnatum (leaves), Caesalpinia bonducella (seeds), Delonix regia (flower), Hedychium spicatum (fruits), Mangifera indica (leaves), Murraya coenigii (leaves) and Syzgium cumini (seeds). Similarly extracts of Cichorium intybus (roots), Ficus religiosa (leaves) and Trigonella foenum-graecum (leaves) demonstrated more antibacterial activity with less antifungal activity. On the other hand Pistacia integerrima (stems) and Rheum emodi (roots) demonstrated more antifungal activity with less antibacterial activity.     

Antibacterial activity of herbal extracts against five plant pathogenic bacteria

The present study was designed to evaluate in vitro antibacterial activity of herbal extracts against five plant pathogenic bacteria (viz. Xanthomonas campestris, Xanthomonas axonopodis pv. punicae, Erwinia spp., Pseudomonas syringae and Xanthomonas citri). Herbal extracts of leaves and rinds of Garcinia indica, rhizomes of Curcuma aromatica, roots of Glyccyrrhiza glabra, leaves of Nyctanthes arbor-tristis and seeds of Vernonia anthelmintica were used for screening. Screening was done using agar well diffusion method. Relatively potent extracts were shortlisted from this study and were further studied to find out their minimum bactericidal concentration (MBC). From the studies, it was observed that extracts of C. aromatica, G. indica and G. glabra have shown lowest MBC values among other tested plant extracts. This study indicates the potential of these potent plant extracts in the management of diseases caused by plant pathogenic bacteria.     

Chemical Composition,Antibacterial, Antioxidant and in Vitro Antidiabetic Activities of Essential Oils from Eruca vesicaria

This work describes the study of the chemical composition and bioactivity of the essential oils (EOs) of the different organs (leaves, flowers, stems and roots) from Eruca vesicaria. According to the GC and GC/MS analysis, all the EOs were dominated by erucin (4‐methylthiobutyl isothiocyanate) with a percentage ranging from 17.9 % (leaves) to 98.5 % (roots). The isolated EOs were evaluated for their antioxidant (DPPH, ABTS and β‐carotene/linoleic acid), antibacterial and inhibitory property against α‐amylase and α‐glucosidase. Most EOs exhibited an interesting α‐glucosidase and α‐amylase inhibitory potential. The roots essential oil was found to be the most active with IC₅₀ values of 0.80±0.06 and 0.11±0.01 μg mL^?1, respectively. The essential oil of roots exhibited the highest antioxidant activity (DPPH, PI=92.76±0.01 %; ABTS, PI=78.87±0.19; and β‐carotene, PI=56.1±0.01 %). The isolated oils were also tested for their antibacterial activity against two Gram‐positive and three Gram‐negative bacteria. Moderate results have been noted by comparison with Gentamicin used as positive control.     

36种中药材体外抗菌活性筛选研究

该文研究36种常用中药材80%乙醇提取物在体外抗临床常见致病菌的抗菌活性。采用药敏纸片法测耐药菌的耐药谱,中药粗粉用80%乙醇浸泡提取,提取液减压浓缩得浸膏,通过琼脂打孔法测定提取物抑菌圈,再通过微量倍比稀释法测定最低抑菌浓度(MIC)和最低杀菌浓度(MBC)。结果表明:36种中药材醇提物中,有15种具有广谱抗菌活性,对实验中各标准菌表现出不同程度的抑制作用,对MRSA抗菌活性也较强。其中,岩陀、卷柏、首乌藤、苏木、乌药、夏枯草6种药材的抗菌活性比较突出,抑菌圈均大于11 mm,细菌对其表现为中高度敏感;它们对7株标准菌的MIC/MBC值除个别为12.5 mg·m L~(-1)以外,均小于1.563 mg·m L~(-1),对16株MRSA的MIC/MBC值均小于1.563 mg·m L~(-1),它们的萃取层活性均小于1 mg·m L~(-1)。所筛选出的15种抗菌活性较强的中药材,可为后续研究其活性单体化合物和作用机制,研发有效的抗多重耐药菌的中药制剂以及解决细菌耐药性问题提供一定的参考。     

Rice dehydrin K-segments have <Emphasis Type="Italic">in vitro</Emphasis> antibacterial activity

Dehydrins are groups of plant proteins that have been shown to response to various environmental stimuli such as dehydration, elevated salinity, and low temperature. However, their roles in plant defense against microbes have not been demonstrated. In an attempt to discover plant antimicrobial proteins, we have screened a rice cDNA library and isolated several cDNAs coding for dehydrins. Protein extracts from Escherichia coli expressing these cDNAs were tested for their activity against Gram-positive bacteria (Bacillus pumilus, B. subtilis, Staphylococcus aureus, and Sarcina lutea) and Gramnegative bacteria (Escherichia coli and Xanthomonas oryzae pv. oryzae). The results indicate that the crude protein extracts exhibited antibacterial activities against the Gram-positive bacteria. However, dehydrins purified by immunoaffinity chromatography were not active against the bacteria. To pinpoint the dehydrin peptides that were responsible for the bactericidal activity, we expressed DNA sequences coding for truncated dehydrins containing either K- or S-segment and found that K-segment peptides, and not S-segment, were responsible for the antibacterial activities against Gram-positive bacteria. Antibacterial assay with synthetic K-segments indicated that the peptides inhibited growth of B. pumilus with minimum inhibition concentration and minimum bactericidal concentration of 130 and 400 μg/ml, respectively.     

Comparative activity against pathogenic bacteria of the root,stem, and leaf of <Emphasis Type="Italic">Raphanus sativus</Emphasis> grown in India

Aqueous, methanol, ethyl acetate, and chloroform extracts of the root, stem, and leaf of Raphanus sativus were studied for antibacterial activity against food-borne and resistant pathogens. All extracts except the aqueous extracts had significant broad-spectrum inhibitory activity. The ethyl acetate extract of the root had the potent antibacterial activity, with a minimum inhibitory concentration (MIC) of 0.016–0.064 mg/ml and a minimum bactericidal concentration (MBC) of 0.016–0.512 mg/ml against health-damaging bacteria. This was followed by the ethyl acetate extracts of the leaf and stem with MICs of 0.064–0.256 and 0.128–0.256 mg/ml, respectively and MBCs of 0.128–2.05 and 0.256–2.05 mg/ml, respectively. The ethyl acetate extracts of the different parts of R. sativus retained their antibacterial activity after heat treatment at 100°C for 30 min, and their antibacterial activity was enhanced when pH was maintained in the acidic range. Hence this study, for the first time, demonstrated that the root, stem, and leaf of R. sativus had significant bactericidal effects against human pathogenic bacteria, justifying their traditional use as anti-infective agents in herbal medicines.     

Antibacterial activity of some salt marsh halophytes and mangrove plants against methicillin resistant Staphylococcus aureus

The antibacterial activity of aqueous and methanol extracts of leaves/shoots of five salt marsh halophytes and six mangroves was studied against methicillin resistant, clinical isolates of Staphylococcus aureus. There was a clear comparability between the salt marsh halophytes and mangroves in their antibacterial action. The mangrove plants possessed higher antibacterial potency than the salt marsh halophytes. The highest activity was recorded with the methanol extract of Excoecaria agallocha followed by the methanol extracts of Aegiceras corniculatum, Lumnitzera racemosa and Ceriops decandra. The minimum inhibitory concentration (MIC) values ranged from 0.125 to 4 mg/mL and 1 to 16 mg/mL for methanol and aqueous extracts, respectively. Further separation of active principle from the potent mangrove plant will be useful for the control of drug resistant strains of S. aureus.     

广西三种真红树植物可培养细菌多样性及其生物活性初筛

为了挖掘真红树植物潜在细菌新物种和生物活性物质,丰富红树林微生物多样性,为新型活性产物开发提供菌株资源。该文从秋茄、木榄和红海榄三种广西来源的真红树植物及其生境中,按根、茎、叶、花、果实和泥土分成22份样品,选用8种不同培养基分离可培养细菌,通过16S rRNA基因序列鉴定,分析其多样性,采用纸片法筛选细菌发酵粗提物的抑菌活性,点植法测试其酶活性。结果表明：(1)共分离获得可培养细菌35株,隶属于23个科28个属,芽孢杆菌属占细菌总数的14.3%,为优势菌属,同时发现11株潜在的新细菌资源。(2)活性筛选获得4株细菌具有抑菌活性,16株细菌具有酶活性,芽孢杆菌属是酶活性优势菌属。综上所述,广西真红树植物可培养细菌多样性丰富,部分细菌具有抑菌活性和酶活性,在新型抗生素和酶应用方面具有一定的开发潜力。     

Brominated Diphenyl Ethers Including a New Tribromoiododiphenyl Ether from the Vietnamese Marine Sponge Arenosclera sp. and Their Antibacterial Activities

A new tribromoiododiphenyl ether ( 1 ) and eight known brominated diphenyl ethers ( 2 – 9 ) were isolated from the MeOH extract of the sponge Arenosclera sp. collected in Vietnam, using repeated open column chromatography and preparative thin layer chromatography. The chemical structure of the new compound 1 was determined by analyses of spectroscopic (1D‐ and 2D‐NMR, and MS) data and by comparison of our data with those reported in the literature. Compounds 1 , 3 , and 8 exhibited strong antibacterial activities against the Gram‐positive bacteria Bacillus subtilis and Staphylococcus aureus and the Gram‐negative bacterium Klebsiella pneumoniae with MIC values ranging from 0.8 to 6.3 μm , while compounds 5 and 7 only displayed activities against Gram‐positive bacteria with MIC values from 0.5 to 3.1 μm . Compound 2 showed activities against the four tested bacteria with MIC values ranging from 0.5 to 6.3 μm .     

In vitro activity of novel in silico‐developed antimicrobial peptides against a panel of bacterial pathogens

Antimicrobial‐peptide‐based therapies could represent a reliable alternative to overcome antibiotic resistance, as they offer potential advantages such as rapid microbicidal activity and multiple activities against a broad spectrum of bacterial pathogens. Three synthetic antimicrobial peptides (AMPs), AMP72, AMP126, and also AMP2041, designed by using ad hoc screening software developed in house, were synthesized and tested against nine reference strains. The peptides showed a partial β‐sheet structure in 10‐mM phosphate buffer. Low cytolytic activity towards both human cell lines (epithelial, endothelial, and fibroblast) and sheep erythrocytes was observed for all peptides. The antimicrobial activity was dose dependent with a minimum bactericidal concentration (MBC) ranging from 0.17 to 10.12 μM (0.4–18.5 µg/ml) for Gram‐negative and 0.94 to 20.65 μM (1.72‐46.5 µg/ml) for Gram‐positive bacteria. Interestingly, in high‐salt environment, the antibacterial activity was generally maintained for Gram‐negative bacteria. All peptides achieved complete bacterial killing in 20 min or less against Gram‐negative bacteria. A linear time‐dependent membrane permeabilization was observed for the tested peptides at 12.5 µg/ml. In a medium containing Mg²⁺ and Ca²⁺, the peptide combination with EDTA restores the antimicrobial activity particularly for AMP2041. Moreover, in combination with anti‐infective agents (quinolones or aminoglycosides) known to bind divalent cation, AMP126 and AMP2041 showed additive activity in comparison with colistin. Our results suggest the following: (i) there is excellent activity against Gram‐negative bacteria, (ii) there is low cytolytic activity, (iii) the presence of a chelating agent restores the antimicrobial activity in a medium containing Mg²⁺ and Ca²⁺, and (iv) the MBC value of the combination AMPs–conventional antibiotics was lower than the MBC of single agents alone. Copyright © 2013 European Peptide Society and John Wiley & Sons, Ltd.     

Antimicrobial effect of different herbal plant extracts against different microbial population

This study evaluates the antimicrobial effects of ethanolic extract of five herbal plants; Guava (Psidium guajava), Sage (Salvia officinalis), Rhamnus (Ziziphusspina Christi), Mulberry (Morusalba L.), and Olive (Oleaeuropaea L) leaves against several microbial population representing Gram positive, Gram negative and Mollicutes; S. aureus, E. coli, Pasteurella multocida, B. cereus, Salmonella Enteritidis and M. gallisepticum using standard agar disc diffusion technique and minimal inhibitory concentration (MIC). Different extracts reveal variable results against the microorganism under study. All extracts have no antibacterial potency for Mycoplasma gallisepticum except Psidium guajava. The results of minimal inhibitory concentration (MIC) and Minimum bactericidal concentration (MBC) of the extracts against the six bacteria ranged from 625 to 5000 μg/ml. The used herbal extract could inhibit the selected microorganism under study with variable minimal inhibitory concentration (MIC) and minimum bactericidal concentration (MBC).     

In vitro pharmacological evaluation and phenolic content of ten South African medicinal plants used as anthelmintics

Helminth infection is regarded as one of the neglected tropical diseases (NTDs). Although the disease is common in rural areas, information on the pharmacology of South African medicinal plants used against this disease is limited. We investigated the efficacy of ten South African medicinal plants against Caenorhabditis elegans. Because of the increased susceptibility of a host to microbial infections and other inflammatory responses associated with helminth infections, the antimicrobial and cyclooxygenase (COX) inhibitory activities of the plants were also investigated. Phenolics including flavonoids, condensed tannins and gallotannins have been linked to many pharmacological activities. Thus, the phenolic content of the plant extracts were quantitatively evaluated. In the three bioassays, organic solvent extracts from Cyathea dregei (roots and leaves), Felicia erigeroides (leaves and stems), Hypoxis colchicifolia (leaves) and Senna petersiana (leaves) exhibited noteworthy pharmacological activities while Acokanthera oppositifolia (leaves) had good COX inhibitory activity. The concentration of phenolics ranged from 56.7 to 1.7 mg GAE/g dry matter in Ocimum basilicum and Cotyledon orbiculata var. dactylopsis, respectively. Flavonoids, condensed tannin and gallotannin content also varied greatly among the plant extracts investigated.     

Antibacterial activity of a sulfated galactan extracted from the marine alga <Emphasis Type="Italic">Chaetomorpha aerea</Emphasis> against <Emphasis Type="Italic">Staphylococcus aureus</Emphasis>

The in vitro antimicrobial activity of the marine green algae Chaetomorpha aerea was investigated against gram-positive bacteria, gram-negative bacteria, and a fungus. The water-soluble extract of algae was composed of a sulfated (6.3%) galactan with a molecular weight of 1.160 × 10⁶ Da and a global composition close to commercial polysaccharides, such as dextran sulfate or fucoidan. The polysaccharide was composed of 18% arabinose, 24% glucose, and 58% galactose. The re-suspended extracts (methanol, water) exhibited selective antibacterial activities against 3 gram-positive bacteria including Staphylococcus aureus (ATCC 25923). Minimum inhibitory concentration and minimum bactericidal concentration tests showed that the sulfated galactan could be a bactericidal agent for this strain (40 mg/mL). The results of this study confirmed the potential use of the green algae Chaetomorpha aerea as a source of antibacterial compounds.     

Phytochemical Diversity,Classification and Antibacterial Activity of Some Medicinal Plant Species from Tabuk (Saudi Arabia)

The main objectives of this study were to investigate the intra-specific and inter-specific phytochemical diversity and classification of nine important medicinal plant species from Tabuk region (KSA), namely (Pulicaria undulata L., Pulicaria incisa Lam., Artemisia herba-alba Asso., Artemisia monosperma Delile, Artemisia judaica L. and Achillea fragrantissima Forssk. from Asteraceae family, Ducrosia flabellifolia Boiss. from Apiaceae family, Thymus vulgaris L. and Lavandula coronopifolia Poir. from Lamiaceae family); to evaluate the antibacterial potentials of the plant extracts, and to inspect the possible associations between phytochemical diversity and contents of different phytochemical classes with the antibacterial activities of plant extracts. GC/MS technique was used to identify phytochemicals in the plant extracts. The standard disk diffusion technique was used to conduct the antibiotic susceptibility against four pathogenic bacterial species (two Gram positive: Staphylococcus aureus and Bacillus subtilis and two Gram negative species: Pseudomonas aeruginosa and Escherichia coli. A total of 160 different phytochemicals belonging to 30 compound classes were separated and identified. A. fragrantissima had the highest phytochemical diversity and P. incisa had the lowest one. Phytochemical beta diversity was 6.2362. Ethanol outperformed other extraction solvents in terms of antibacterial activity, while Pulicaria undulata and T. vulgaris ranked highest among plants in this regard. Gram positive bacterial species were more sensitive to plant extracts compared to Gram negative species. Phytochemical diversity and antibacterial activity of plant extracts against E. coli and P. aeruginosa were positively correlative, terpenoid and benzene & substituted derivative contents exhibited significant (p<0.05) positive correlations with the antibacterial activity against E. coli, terpenoid contents also showed positive correlation with activity against P. aeruginosa; benzene & derivative showed positive correlation with activity against the rest of bacterial species,     

In vitro evaluation of Datura innoxia (thorn-apple) for potential antibacterial activity

Various parts of Datura innoxia were examined for potential antibacterial activity by preparing their crude aqueous and organic extracts against Gram-negative bacteria (Escherichia coli and Salmonella typhi) and Gram-positive bacteria (Bacillus cereus, Bacillus subtilis and Staphylococcus aureus). The results of agar well diffusion assay indicated that the pattern of inhibition depends largely upon the plant part, solvent used for extraction and the organism tested. Extracts prepared from leaves were shown to have better efficacy than stem and root extracts. Organic extracts provided potent antibacterial activity as compared to aqueous extracts. Among all the extracts, methanolic extract was found most active against almost all the bacterial species tested. Gram-positive bacteria were found most sensitive as compared to Gram-negative bacteria. Staphylococcus aureus was signifi cantly inhibited by almost all the extracts even at very low MIC followed by other Gram-positives. For Escherichia coli (a Gram-negative bacterium), the end point was not reached for ethyl acetate extract while it was very high for other extracts. The study promises an interesting future for designing a potentially active antibacterial agent from Datura innoxia.     

Defensin‐like peptide3 from black solder fly: Identification,characterization, and key amino acids for anti‐Gram‐negative bacteria

An antibacterial peptide was isolated from a black soldier fly, Hermetia illucens. The molecular mass of this peptide was established as 4247.37 by matrix‐assisted laser desorption/ionization‐time of flight mass (MALD‐TOF MS) spectrometry. The amino acid sequence of the mature peptide was determined by N‐terminal sequencing using Edman degradation, combined with cDNA sequencing of the previously reported defensin‐like peptide (DLP) 3. Analysis of the minimal inhibitory concentration (MIC) revealed that DLP3 had potent activity against Gram‐positive and negative bacteria, but DLP4 had only anti‐Gram‐positive activity as previously reported. Recombinant DLP3 and DLP4 were overexpressed in Escherichia coli, and antibacterial activities were identical to DLPs purified from H. illucens hemolyph. In silico analysis revealed that only six amino acid sequences were different between DLP3 and DLP4, but antibacterial activity against Gram‐negative bacteria differed. Therefore these amino acid variants may be key amino acids (Gly‐10, Val‐18, Met‐23, Arg‐25, Asp‐32, Arg‐40) related to killing Gram‐negative bacteria.