Common Human Pathogenic Bacteria Research Articles

Chemical composition, antibacterial and antifungal activities of Ruta graveolens L. volatile oils

AbstractThe Ruta graveolens L. (Rutaceae) plant is used medicinally as a homeopathic remedy in various areas of the world. In this study, volatile oils were extracted from the areal parts of the plant which was collected from southern India, then investigated for its chemical constituents and antimicrobial activities. The volatile oils were extracted by hydrodistillation using a Clevenger apparatus and samples were simultaneously analyzed with GC and GC-MS. As a result, a total of 13 chemical constituents were characterized. Representing 100% of the total oil with 2-ketones are the major groups. The principal components were identified, undecanone-2 (43.66%), 2-nonanone (16.09%), 2-acetoxy tetradecanone (14.49%), and nonyl cyclopropanecarboxylate (9.22%), respectively. The extracted volatile oil showed antibacterial activity against gram-positive and gram-negative bacteria, resulting in a number of common human pathogenic bacteria including methicillin-resistant Staphylococcus aureus and the yeast Candida...

Microbiological evaluation of drinking water sold by roadside vendors of Delhi, India

Delhi has emerged as one of the greenest capital city of the world. Microbiological assessment of drinking water emphasizes estimation of the hygienic quality of the water sold with reference to community health significance. This study was conducted to evaluate the quality of drinking water sold by roadside vendors in east, west, north and south zones of capital of India. A total number of 36 samples (nine from each zone) were collected as per national guidelines and studied for microbiological assessment. All the drinking water samples were collected in gamma-sterilized bottles and were kept in an ice pack to prevent any significant change in the microbial flora of the samples during the transportation. The water samples were transported to the laboratory in vertical position maintaining the temperature 1–4 °C with ice pack enveloped conditions. Samples were analyzed for total MPN coliform per 100 ml and for the presence and absence of common human pathogenic bacteria such as Escherichia coli, Salmonella, Staphylococcus aureus and Pseudomonas aeruginosa. All the samples were found to be contaminated with coliform organisms in the range of 14 to >1600 per 100 ml of sample. Out of 36 water samples, the occurrence of E. coli was 61 %, Salmonella 25 % S. aureus 14 % and P. aeruginosa 53 % as 22, 9, 5 and 19 samples were found contaminated, respectively. The numbers of coliform bacteria and presence of some common pathogenic bacteria suggested that the quality of drinking water sold by roadside vendors is not within the Indian standard and WHO guidelines laid down for drinking water quality. Hence, there is a vital need to study the root cause in terms of hygiene, sanitation of vendors and source of contamination to prevent waterborne diseases.

Antimicrobial potential of alkaloids and flavonoids extracted from <i>Tamarix aphylla</i> leaves against common human pathogenic bacteria

Background: Alkaloids and flavonoids are secondary metabolites extracted from different medicinal plants. Tamarix aphylla a traditionally valuable medicinal plant; was used for the extraction of alkaloids and flavonoids in order to evaluate their antibacterial activity.Methodology: The leaves of the plant were collected from district Kohat, Pakistan, and their alkaloids and flavonoids were extracted with ethanol and methanol, respectively. Four bacteria i.e. Gram positive (Staphylococcus aureus) and Gram negative (Escherichia coli, Salmonella typhi and Pseudomonas aeruginosa) were selected for the biological screening of these phyto-constituents.Results: The concentration of alkaloids was found to be more in the leaves of Tamarix aphylla than flavonoids. The extracted phytochemicals showed varied inhibition zones against tested bacterial isolates. Alkaloids showed highest inhibitory activity against Staphylococcus aureus (14±0.6 mm) followed by Pseudomonas aeruginosa (13±0.7 mm). Conversely, flavonoids showed the highest inhibitory affect against Salmonella typhi (17±0.7 mm) followed by Staphylococcus aureus (14±0.7 mm). However, both extracts showed the lowest inhibitory effects against Escherichia coli.Conclusions: It was concluded that the alkaloids and flavonoids from Tamarix aphylla leaves have antimicrobial potential against common human bacterial pathogens. However, flavonoids were found to be more active phytochemical against tested bacterial strains as compared to alkaloids.Keywords: Kohat; Medicinal plants; Phytochemical screening; In-vitro activity; Bacterial strains.

Antimicrobial Potentials of Apis Multiflora Honey in Combination with Coffee and Cinnamon Extracts against Common Human Pathogenic Bacteria

Background: Traditional medicines have been used widely by the people of Ethiopia for treatment of various ailments. However, scientific evidences regarding their antibacterial potential are scarce. The present study aim to assess an in vitro antibacterial activity of Apis multiflora honey in combination with coffee and cinnamon bark extracts against the standard and clinical isolates of human pathogenic bacteria. Methods: Antimicrobial activities of honey and the extracts were tested against Escherichia coli, Citrobacter species, Staphylococcus epdermidis, Staphylococcus aureus, Pseudomonas aeruginosa (ATCC 27853) and Staphylococcus aureus (ATCC 2923). Agar well diffusion and micro-well broth dilution techniques were used to determine the antibacterial activity and minimum inhibitory concentration. Result: Honey exerted a maximum bacterial inhibition against Citrobacter species and E. coli (29 mm). Coffee extracts displayed best antibacterial activity against S. aureus (25-26 mm) and cinnamon extract exhibited the maximum inhibitory effect against S. epidermidis (31 mm). The combination of honey with cinnamon was most effective against P. aeruginosa (27 mm), whereas the combination of honey with coffee and cinnamon extracts was most effective against S. aureus ATCC 2923 (35 mm). The antibacterial activity exerted by a reference antibiotic ceftraxone against different test strains ranged from 24-37 mm. Conclusion: Coffee and cinnamon extracts, and honey have demonstrated a broad spectrum antibacterial effect. Our data indicating that these natural products have potential to be used as alternative antimicrobials for treatment of pathogenic bacteria. Thus, we recommend further investigations of each extract to elucidate bioactive compounds responsible for the observed antibacterial activity.

An alkaloid of Norway spruce (Picea abies) possesses powerful antibacterial and antifungal potential

Norway spruce, Picea abies, along with other species of Picea contains a number of small molecular mass alkaloids [1]. To the best of our knowledge there exists no earlier publications on the antimicrobial effects of spruce alkaloids. On the other hand, there are a number of publications on the antibacterial effects of essential oils and oil rich fractions of spruce [2]. Spruce needle oil and decoctions of young spruce are traditionally used for treatment of cold, bronchitis, symptoms of fever and stomach ailments, among others. The present study was carried out to evaluate the antimicrobial effects of alkaloid EpI found in P. abies. Focus was put on bacterial strains causing food poisonings as well as other common human pathogenic bacteria and two Candida species. The antimicrobial effects were evaluated using microplate methods. The lowest minimum inhibitory concentration of 5.37 µg/ml was recorded against Pseudomonas aeruginosa, Enterococcus faecalis, Candida glabrata and Candida albicans. For comparison, the conventionally used tetracycline gave a MIC of 15.6 µg/ml against P. aeruginosa and amphotericin B a MIC of 1.95 µg/ml against C. albicans. Very promising MIC value of 10.75 µg/ml was recorded against Staphylococcus aureus and Bacillus cereus, both common food poisoning bacteria. In addition promising MIC of 43 µg/ml was recorded against Salmonella enterica. Further studies will be performed on testing this antimicrobially promising alkaloid EpI for cytotoxicity against fibroblasts and other normal cell lines.

Antibacterial activity of Punica granatum L. peels extracts against three common human wound pathogenic bacteria and formulation of topical ointment and hydrogel pharmaceutical forms

Ethanolic and aqueous extracts of Punica granatum L. peels were prepared and tested for antibacterial activity against Escherichia coli and Pseudomonas aerogenosa as gram negative bacteria and Staphylococcus aureus as gram positive bacteria. The suitability of extracts for topical pharmaceutical preparations was attempted by formulation of extracts into simple ointment and hydrogel pharmaceutical dosage forms. The antibacterial activity was assessed by agar well diffusion method using four different concentrations for both extracts include (100, 10, 1, 0.1mg/ml). Ethanolic and aqueous extracts showed antibacterial activity against Staphylococcus aureus, with lowest inhibition zone of 12mm at 0.1mg/ml. The same result was obtained for ethanolic extract against E. coli, whereas, aqueous extract showed 9mm zone of inhibition. The lowest inhibition zone against Pseudomonas aerogenosa,was 10mm at 0.1mg/ml of ethanolic extract and 1mg/ml of aqueous extract which showed resistance at 0.1mg/ml. From this it is concluded that both extracts have inhibitor effect on the growth of both gram positive and negative bacteria and ethanolic extracts exhibited higher degree of antibacterial activity as compared to aqueous extract. In present study, simple ointment containing (10%w/v) of ethanolic extract and hydrogel containing (10%w/v) of aqueous extract were prepared successfully.

Antimicrobial, Antioxidant, and Cytotoxic Activities of the Essential Oil of Tarchonanthus camphoratus

The leaf essential oil of Tarchonanthuscamphoratus(As teraceae) was obtained by hydrodistillation and analyzed by GC-MS. Fifty-six components were characterized, representing 94.2% of the total oil with oxygenated monoterpenes (48.3%) and oxygenated sesquiterpenes (32.7%) as the major groups. The principal constituents were identified as endo-fenchol (21.2%), trans-pinene hydrate (8.8%), caryophyllene oxide (7.5%), α-terpineol (6.4%), τ-cadinol (6.4%), and α-cadinol (5.2%). The essential oil was evaluated for its antimicrobial activity using a disc diffusion assay resulting in the moderate inhibition of a number of common human pathogenic bacteria, including methicillin-resistant Staphylococcus aureus(MRSA) and the yeast Candida albicans. The inhibition zones varied from 10 to 14mm/disc. Furthermore, the antioxidant capacity of the essential oil was examined using an in vitroradical scavenging activity test. The T. camphoratus essential oil scavenged 1,1-diphenyl-2-picrylhydrazyl radical (DPPH), resulting in an IC50value of 5.6 mg/mL. At concentrations of 100 and 50μg/mL, the oil showed cytotoxic activity, with growth inhibition of 59.1% (±4.2), and 16.2% (±8.7) against HT29 tumor cells (human colonic adenocarcinoma cells), respectively(IC50 = 84.7 ± 7.5 μg/mL).

Apigenin alleviates the symptoms ofStaphylococcus aureuspneumonia by inhibiting the production of alpha-hemolysin

Staphylococcus aureus is a common human pathogenic bacteria that can cause serious infections, including lethal staphylococcal pneumonia. The development of antimicrobial resistance has limited treatment options for this pathogen; consequently, novel antibiotics and strategies are urgently desired to combat these infections. In recent years, virulence factors secreted by pathogenic microorganisms have been developed as targets for drug discovery. Alpha-hemolysin, a pore-forming cytotoxin that is secreted by most S.aureus strains, is essential for the pathogenesis of S.aureus pneumonia. In this study, we report that apigenin, a compound extracted from parsley that has no antimicrobial activity vs. S.aureus in vitro, can remarkably decrease the production of α-hemolysin at low concentrations. When added to the A549 cells and S.aureus co-culture system, apigenin protected A549 cells from α-hemolysin-mediated injury. Furthermore, in vivo tests indicated that apigenin alleviated injury of the lung tissue and decreased cytokine levels in the bronchoalveolar lavage fluid in the mouse model of S.aureus pneumonia.

Chemical composition and in vitro evaluation of antioxidant and antibacterial activities of the root oil of Ridolfia segetum (L.) Moris from Tunisia

The present work describes the chemical composition and evaluates the antibacterial and the antioxidant properties of root oil from Ridolfia segetum, a traditional medicinal plant widely distributed in Tunisia. The essential oil, analysed by combination of GC, GC/MS and 13C-NMR, was dominated by dillapiole (47.4%) and myristicin (19.2%). The antioxidant potential of the essential oil was evaluated using the 2,2′-diphenyl-1-picrylhydrazyl free radical scavenging method. The phenylpropanoid-rich root oil possesses good antioxidant properties (IC50 = 38 mg mL−1). The essential oil was evaluated for its antibacterial activity using the microdilution assay, resulting in the inhibition of a number of common human pathogenic bacteria as well as of some clinical and environmental isolated strains. The minimum inhibitory concentrations of the essential oil varied between 1.25 and 5 mg mL−1 and the minimum bactericidal concentrations were superior to 5 mg mL−1 of oil for most strains. These results may suggest that the root oil of R. segetum possesses compounds with antibacterial and antioxidant capacities, and therefore can be explored as a natural preservative ingredient in food and/or for pharmaceutical preparations.

A comparative evaluation of antibacterial potential of some plants used in indian traditional medicine for the treatment of microbial infections

A comparative in vitro antibacterial potential of extracts (aqueous and ethanol) of five important medicinal plants (Aegle marmelos, Azadirachta indica, Terminalia chebula, Mangifera indica and Ocimum sanctum) were investigated using microbial growth inhibition assays against the common human pathogenic bacteria (Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli) of clinical origin. All the plant materials showed varying degrees of strain specific inhibitory action and ethanol extract of the plant materials showed higher antibacterial activity than their aqueous counterparts. Besides, T. chebula and A. marmelos had the strongest antibacterial activity out of which, T. chebula possessed a wider spectrum and a superior antibacterial potential over the others. The bioactive compounds of T. chebula might have potential as therapeutic agents for the treatment of common bacterial infections.

Flower and Root Oils of the Tunisian Daucus carota L. ssp. maritimus (Apiaceae): Integrated Analyses by GC, GC/MS, and 13C‐NMR Spectroscopy, and in vitro Antibacterial Activity

The essential oils from flowers and roots of Daucus carota L. ssp. maritimus were obtained by hydrodistillation and analyzed by combination of GC, GC/MS, and (13)C-NMR. The chemical composition of the flower and root oils of this subspecies is reported here for the first time. Thirty-two and six compounds were identified in flower and root oils, respectively. A remarkable difference was found between the constituent percentages of the two organs. The chemical composition of the essential oil from flowers was characterized by a high proportion of monoterpene hydrocarbons (68.4%) and belonged to the sabinene (4; 51.6%) chemotype. The oxygenated monoterpenes represented the second major fraction of the same oil among which terpinen-4-ol (11.0%) was the predominant compound. Root oil exhibited a surprisingly different composition. Phenolic derivatives (76.3%), myristicin (31; 29.7%), and dillapiole (32; 46.6%) constituted the main fraction. The antibacterial effect resulted in the inhibition of a series of common human pathogenic bacteria, and of some clinically and environmentally isolated strains with significant MIC and MBC values.

<i>In-vitro</i> Antimicrobial Efficacy of Carex Powerful Antiseptic Liquid

The Paterson Zochonis Industries in Lagos, Nigeria recently produced Carex Powerful Antiseptic Liquid, which was investigated for antimicrobial activities against common human skin pathogenic bacteria, yeasts and a dermatophyte including Staphylococcus aureus, Pseudomonas aeruginosa, Malassezia furfur, Candida albicans and Trichophyton mentagrophytes. The microbes were challenged in-vitro with 0.7% and undiluted Carex antiseptic liquids for a period between 30 seconds and 120 seconds and the microbial cell reduction rates were determined at every 30 seconds contact by time kill test. Both diluted and undiluted Carex antiseptic liquids produced 100% reduction in all the microbial cells tested except Pseudomonas aeruginosa in which 62% and 100% cell reductions were observed for diluted and undiluted Carex antiseptic liquids respectively within 30 seconds of contact time. It is concluded that Carex Powerful Antiseptic liquid made by the PZ Industries has antimicrobial activities but its non-toxicity to human skin should be proven by subjecting the preparation to clinical trial. Keywords: Carex Antiseptic Liquid, Time Kill Test. Nigerian Journal of Health and Biomedical Sciences Vol. 7 (2) 2008: pp. 44-50

GC, GC-MS and 13C NMR Spectroscopy Integrated Analyses and in vitro Antibacterial Activity of Ridolfia segetum Essential Oils from Tunisia

The present work describes the chemical composition and evaluates the antibacterial properties of the leaf and the flower oils from Ridolfia segetum, a traditional medicinal plant widely distributed in Tunisia. The essential oils were analysed by combination of GC, GC-MS and 13C NMR and 17 components, accounting for 88.7 % and 88.6 % of the oil, respectively, were identified. The oils from fresh flowers and leaves were characterized by high contents of aphellandrene (34.7 %and 47.8 %), terpinolene (23.7 and 9.0 %), p-cymene (4.8 and 8.7 %), β-phellandrene (4.8 and 7.2 %) and limonene (3.7 and 3.9 %). Five oxygenated components were isolated from the flower oil. The essential oils and isolated compounds were evaluated for their antibacterial activity using the microdilution assay resulting in the inhibition of a number of common human pathogenic bacteria as well as of some clinical and environmental isolated strains. The minimum inhibitory concentrations (MICs) varied between 1.25 and 5 mg/mL for essential oils and between 0.62 and 5 mg/mL for pure compounds and hydrocarbon fraction. The minimum bactericidal concentrations (MBCs) were 5 mg/mL for most strains and they varied between 1.25 and more than 10 mg/mL for pure compounds. The results may suggest that the essential oils of R. segetum contains compounds with antibacterial activity, and therefore can be explored as a natural preservative ingredient in food and/or pharmaceutical preparations.

Effect of Maturation on the Composition and Biological Activity of the Essential Oil of a Commercially Important Satureja Species from Turkey: Satureja cuneifolia Ten. (Lamiaceae)

The essential oil obtained by hydrodistillation from aerial parts of Satureja cuneifolia Ten., collected in three different maturation stages such as preflowering, flowering, and postflowering, were analyzed simultaneously by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). Thymol (42.5-45.2%), p-cymene (19.4-24.3%), and carvacrol (8.5-13.2%) were identified as the main constituent in all stages. At the same time, the essential oils and main components were evaluated for their antimicrobial activity using a microdilution assay resulting in the inhibition of a number of common human pathogenic bacteria including methicillin-resistant Staphylococcus aureus (MRSA) and the yeasts Candida albicans and Candida tropicalis. The minimum inhibitory concentrations (MIC) varied between 62.5 and 250 microg/mL within a moderate antimicrobial activity range. Furthermore, the antioxidant capacity of the essential oils and major components thymol and carvacrol were examined in vitro. The essential oils obtained from S. cuneifolia in three different stages and its main components were interacted with 1,1-diphenyl-2-picrylhydrazyl (DPPH (*)) as a nitrogen-centered stable radical, resulting in IC 50 = 1.6-2.1 mg/mL. In addition, the effects on inhibition of lipid peroxidation of the essential oils were assayed using the beta-carotene bleaching method. All of the tested oils inhibited the linoleic acid peroxidation at almost the same level as butylated hydroxytoluene (BHT) (93.54-94.65%). BHT and ascorbic acid were used as positive controls in the antioxidant assays.

Antimicrobial and antioxidant activities of the essential oil of Chaerophyllum libanoticum Boiss. et Kotschy

Chaerophyllum libanoticum Boiss. et Kotschy from Apiaceae, is collected and used as a food plant in Turkey. The essential oil obtained by hydrodistillation from the crushed fruits of C. libanoticum collected from Osmaniye, Southern Turkey, was simultaneously analysed by gas chromatography (GC) and gas chromatography–mass spectrometry (GC–MS). As a result, a total of seventy three components were characterized, representing 98.3% of the total oil with monoterpenes as the major group. The principal constituents were identified as β-phellandrene (17.6%), limonene (15.9%), β-pinene (8.8%), and sabinene (8.5%), respectively. The essential oil was evaluated for its antimicrobial activity using a microdilution assay resulting in the inhibition of a number of common human pathogenic bacteria including methicillin-resistant Staphylococcus aureus (MRSA) and the yeast Candida albicans. The minimum inhibitory concentrations (MIC) varied between 0.25 and 0.5 mg/ml which is within a moderate antimicrobial activity range. Furthermore, the antioxidant capacity of the essential oil was examined using an in vitro radical scavenging activity test. The C. libanoticum essential oil scavenged 1,1-diphenyl-2-picrylhydrazyl radical (DPPH ), resulting in IC 50 > 30 mg/ml. In addition, the effect on inhibition of lipid peroxidation of the essential oil was assayed using β-carotene bleaching and haemoglobin induced linoleic acid peroxidation methods resulting in 16% antioxidative activity.

Bacterial superantigen exposure after resolution of influenza virus infection perturbs the virus-specific memory CD8(+)-T-cell repertoire.

Heterologous viral infections have been shown to impact the preexisting memory CD8(+)-T-cell repertoire. Bacterial superantigens are products of common human pathogenic bacteria, including staphylococci and streptococci, that are potent T-cell-stimulatory molecules. In this report, we show that exposure to staphylococcal enterotoxin B, a bacterial superantigen, causes a selective functional deletion of cross-reactive influenza virus-specific CD8(+) memory T cells. This perturbation of the memory repertoire can have a significant impact on viral clearance after secondary challenge.