Research - Bacterial Infections
Anti-bacterial activity of peppermint (Mentha piperita) extracts against some emerging multi-drug resistant human bacterial pathogens
Mohammed Helmy Faris Shalayel, Professor of Biochemistrya, *, Ahmed Morad Asaad, Professor of Microbiologya , Mohammed Ansar Qureshib , Amar Babiker Elhusseinc
Abstract
Various plant extracts have great potential against infectious agents and can be used for therapeutic purposes. This study was carried out to evaluate the antimicrobial activities of peppermint (Mentha piperita) extracts against 10 multidrug resistant (MDR) pathogenic bacterial clinical isolates.The antibacterial activities of ethanol, methanol, ethyl acetate and chloroform peppermint extracts were assessed using the standard minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) methods. Overall, the ethyl acetate extract of peppermint had strong growth inhibitory effects on the tested pathogens, followed by the chloroform, ethanol and methanol extracts. The inhibitory activity of the ethyl acetate extract against all Gram-negative pathogens was higher than that of chloroform (10–80 mg/ml), methanol (10– > 80 mg/ml) and ethanol (40– > 80 mg/ml). The lowest MIC value was seen for Streptococcus pyogenes (1.25 mg/ml for ethyl acetate extract), followed by methicillin-resistant Staphylococcus epidermidis (MRSE) and Enterococcus faecalis (2.5 mg/ml for ethyl acetate extract).The MBC values of all extracts were higher than the corresponding MIC values for the majority of pathogens. This study highlights the potential antibacterial activity for M. piperita extracts, especially the ethyl acetate extract, against MDR S. pyogenes, E. faecalis, methicillin-resistant Staphylococcus aureus (MRSA), MRSE and carbapenem-resistant E. coli, and Klebsiella pneumonia clinical isolates. Further in vitro and in vivo studies on a large number of clinical isolates of MRSA, Acinetobacter baumannii and Stenotrophomonas maltophilia are necessary to further investigate and standardize the inhibitory effect of peppermint extracts against these emerging pathogens.
Source : Journal of Herbal Medicine
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Chemical composition, antimicrobial and antibiotic potentiating activity of essential oils from 10 tropical medicinal plants from Mauritius
Hightlights
• Essential oils (EOs) from 10 tropical medicinal plants were extracted by hydrodistillation.
• Eighteen microorganisms were used to evaluate the antimicrobial potential of the EOs as well as their ability to potentiate conventional antibiotics.
• EOs showed potent bactericidal, fungicidal and antibiotic potentiating activity.
• Twenty eight major compounds were identified using GC–MS composed of monoterpenes hydrocarbons.
• Studied EOs may be exploited as complementary and alternative therapies against infectious diseases.
Abstract
Infectious diseases and antibiotic resistance have become a public health issue of increasing magnitude. The discovery and development of new antimicrobial agents from herbal medicine to address this problem has attracted much attention and should be given high priority. This study was designed to evaluate the antimicrobial properties of essential oils (EOs) extracted from 10 common medicinal plants of Mauritius. Eighteen microorganisms (bacterial and fungal isolates) were used to evaluate the antimicrobial potential of the EOs as well as their ability to potentiate conventional antibiotics. The phytochemical profile was established using Gas chromatography–Mass spectrometry method. Antibacterial activities were recorded with low minimal inhibitory concentration for 4 of the EOs using the microbroth dilution assay. A synergistic effect of the EO ofCitrus hystrix D.C., Citrus reticulate (Blanco) and Melaleuca quinquenervia S.T. Blake (Cav.) were observed against Escherichia coli (ATCC 25922) and Staphylococcus epidermidis (ATCC 12228) when combined with gentamicin. Fungicidal and fungistatic effects of the EOs were observed among all the fungi irrespective of the family except forTrichophyton mentagrophytes. Twenty eight major compounds were identified and predominantly composed of monoterpene hydrocarbons at a dose-content ranging from 0.68 to 88.58%. This study has provided key information on the antimicrobial property and phytochemical composition of some tropical medicinal plants. Hence, EOs studied in the present investigation may be considered as potential medicinal candidates that could be exploited as complementary and alternative therapies for the treatment and management of infectious diseases.
Source : Journal Herbal Medicine
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Piperine Plays an Anti-Inflammatory Role in Staphylococcus aureus Endometritis by Inhibiting Activation of NF-κB and MAPK Pathways in Mice
Wen-jun Zhai, Zhen-biao Zhang, Nian-nian Xu, Ying-fang Guo, Changwei Qiu, Cheng-ye Li, Gan-zhen Deng, and Meng-yao Guo
Abstract
Endometritis is commonly caused by pathogenic microorganisms, including Staphylococcus aureus (S. aureus). Piperine, which is a natural medicine, has shown a variety of biological activities. To explore the effect and mechanism of piperine on S. aureus endometritis, a mouse model of S. aureus endometritis was successfully established in the present study. Histopathological changes were observed with H&E staining, cytokines were analyzed by ELISA, mRNA was analyzed by qPCR, and proteins were detected by western blot. The results showed that piperine could significantly alleviate inflammatory injury in S. aureus endometritis. The qPCR and ELISA results showed that piperine effectively reduced the S. aureus-induced overexpression of TNF-α, IL-1β, and IL-6 but increased the expression of IL-10. The S. aureus-induced inflammation was related to TLR-2 and TLR-4 because the results showed that their expression was increased in S. aureus infection but then decreased with piperine treatment. To further confirm that piperine caused an anti-inflammatory response by targeting NF-κB and MAPKs, the expression of I-κB, p65, p38, ERK, and JNK was measured. The phosphorylation of I-κB, p65, p38, ERK, and JNK was inhibited by piperine in a dose-dependent manner. All of the results indicated that piperine may be a potential anti-inflammatory drug both in endometritis and in other S. aureus-induced diseases.
Source : Evidence Based Complementary and Alternative Medicine
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Antimicrobial and antioxidant efficacy of Citrus limon L. peel extracts used for skin diseases by Xhosa tribe of Amathole District, Eastern Cape, South Africa
W.M. Otang, A.J. Afolayan
Abstract
Skin diseases such as dermatitis, prurigo, and scabies present a major health concern in the Eastern Cape, South Africa, where there is a scarcity of dermatologists, compounded by the fact that most dermatologists are centered near urban areas and are not accessible to 70% of the rural population. Hence, many people still depend to a large extent on traditional herbs such as Citrus limon for the treatment of skin diseases. The aim of this study was therefore to screen the acetone and ethanol extracts of C. limon for its antioxidant potential and antimicrobial efficacy agents against a panel of microbes implicated in skin diseases. The highest antibacterial activity was obtained with the acetone extract of C. limon against Enterococcus faecalis and Bacillus subtilis, and the most susceptible bacteria based on the overall mean inhibition diameters were the gram-negative Salmonella typhimurium, Shigella sonnei and the gram-positive E. faecalis and B. subtilis. Both extracts were active against Candida glabrata. The DPPH scavenging activity of the acetone extract was not significantly different from those of vitamin C and rutin. Nitric oxide scavenging activity was lowest in the ethanol extract of C. limon. The reducing ability of both plant extracts was significantly lower than that of vitamin C and rutin. The fact that both extracts of C. limon exhibited a broad spectrum of antibacterial activity and comparable efficacy to the synthetic antioxidants highlights the medicinal value of C. limon as a potential source for drug development amidst the obvious dearth of effective and safe antibacterial drugs, and also validates the ethnotherapeutic claim of the plant.
Source : South African Journal of Botany
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In vitro antibacterial activity and in vivo efficacy of hydrated clays on Mycobacterium ulcerans growth
- Sarojini Adusumilli and
- Shelley E. Haydel
Abstract
Background
Buruli ulcer, caused by Mycobacterium ulcerans, is a localized skin lesion that can progress to extensive ulceration and necrosis if left untreated. Unpublished studies of hydrated clays for therapeutic, topical treatment of Buruli ulcer suggest that specific clay mineral products may have beneficial effects on wound healing. In this study, we evaluated the in vitroantibacterial activity of a panel of clay mixtures and their derivative leachates against M. ulcerans and assessed the in vivoefficacy of topically-applied, hydrated clays on Buruli ulcer progression in mice infected with M. ulcerans.
Methods
M. ulcerans 1615 was incubated with 10 % suspensions of CB07, CB08, CB09, CB10, and BY07 clay mixtures, and survival was determined over 28 days. For animal experiments, we examined the effect of topical hydrated clay therapy on Buruli ulcer progression in vivo in mouse tails subcutaneously infected with M. ulcerans 1615.
Results
The CB07, CB08, and CB09 clays exhibited bactericidal activity against M. ulcerans after 7, 14, 21, and 28 days of incubation. In contrast, clay leachates exhibited inhibitory, bacteriostatic effects on M. ulcerans growth in vitro. After establishing an ulcerative M. ulcerans infection for three months, ulcerated regions of the tails were treated once daily (five consecutive days per week) for 22 days with hydrated CB09 clay poultices. Mice in the clay treatment group exhibited healing as assessed by gross morphological changes and a reduction in M. ulcerans present in the wounds.
Conclusions
These data reveal that specific clays exhibit in vitro bactericidal activity against M. ulcerans and that hydrated clay poultices may offer a complementary and integrative strategy for topically treating Buruli ulcer disease.
Source : BMC Complementary and Alternative Medicine
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Evaluation of the Antibacterial Activity of a Sizable Set of Essential Oils Plant J* and Stephens B
Abstract
Health issues related to bacterial infections, and the rise of bacterial resistance, have pushed the need for improved control options. Recently there has been a renewed interest in testing essential oils as antimicrobials, and combinatorial therapy combining conventional antibiotics and essential oils is ongoing. The popularity of essential oils as homeopathic remedies has increased in recent years due to the thought that natural products might prove safer than ingredients currently in consumer products. Several scientific reports exist relating to the efficacy of essential oils in controlling microbes, however most of these publications are either microbe centric, or are specific to one particular essential oil or oil constituent. This work was undertaken to develop a more comprehensive picture of the antibacterial effects of essential oils by evaluating the effectiveness of a large panel of essential oils against four diverse strains of bacteria (Escherichia coli, Staphylococcus aureus, Micrococcus luteus, and Serratia marcescens). Of the essential oils tested, cinnamon bark, lemongrass, oregano, and thyme oils were the most potent, and had activity comparable to a concentration of a penicillin-streptomycin solution commonly used to inhibit bacterial growth. This study supports the idea that certain essential oils could play an important role in the development of antimicrobial products.
Source : Journal Medicinal and Aromatic Plants
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Antifungal and Antibacterial Metabolites from a French Poplar Type Propolis
Séverine Boisard,1 Anne-Marie Le Ray,1 Anne Landreau,1 Marie Kempf,2,3 Viviane Cassisa,2,3 Catherine Flurin,4 and Pascal Richomme1
Abstract
During this study, the in vitro antifungal and antibacterial activities of different extracts (aqueous and organic) obtained from a French propolis batch were evaluated. Antifungal activity was evaluated by broth microdilution on three pathogenic strains: Candida albicans, C. glabrata, and Aspergillus fumigatus. Antibacterial activity was assayed using agar dilution method on 36 Gram-negative and Gram-positive strains including Staphylococcus aureus. Organic extracts showed a significant antifungal activity against C. albicansand C. glabrata (MIC80 between 16 and 31 µg/mL) but only a weak activity towards A. fumigatus (MIC80 = 250 µg/mL). DCM based extracts exhibited a selective Gram-positive antibacterial activity, especially against S. aureus (SA) and several of its methicillin-resistant (MRSA) and methicillin-susceptible (MSSA) strains (MIC100 30–97 µg/mL). A new and active derivative of catechin was also identified whereas a synergistic antimicrobial effect was noticed during this study.
Source : Evidence Based Complementary and Alternative Medicine
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Antibacterial activity of Acmella paniculata extract on human pathogenic bacteria
Krishna M.P, Rinoy Varghese, Mahesh Mohan, A.A. Mohamed Hatha
Abstract: The use of plant in treatment of infectious diseases is common in traditional medicine. On the basis of ethno pharmacological and taxonomic information, antibacterial activity of aqueous extract of different parts (leaf, root, shoot and flower) of Acmella paniculata were determined by agar diffusion-method against some human pathogenic bacteria. The antibacterial screening of aqueous extract carried out in vitro against the following bacteria viz., Bacillus subtilis, Escherichia coli, Salmonella typhi, Staphylococcus aureus, Vibrio cholerae and Vibrio parahaemolyticus. The results of the present study showed that the aqueous extracts of flower and leaf showed relatively high activity against the tested pathogens and theroot showed comparatively low antibacterial activity. Root showed moderate activity against the tested pathogens. Vibrio cholerae and Vibrio parahaemolyticus were the most resistant strains on Acmella paniculata extracts. A maximum inhibition zone of 27 mm and 24 mm showed by flower and leaf extract respectively against Salmonella typhi. The present screening result demonstrated that the Indian traditional medicinal plant Acmella paniculata aqueous extracts has potent antibacterial activity and the studied plant may be new source for novel antibacterial compound discovery for treating drugs resistant human pathogens.
Source : Intl Journal of Herbal Medicine
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A Comparison of the Anti-Staphylococcus aureus Activity of Extracts from Commonly Used Medicinal Plants
Rebecca Snowden, ND,1Heather Harrington, ND,1,2Kira Morrill, ND,1LaDeana Jeane, ND,1Joan Garrity, ND,1Michael Orian, ND,1Eric Lopez, ND,1Saman Rezaie, ND,1Kelly Hassberger, ND,1Damilola Familoni, ND,1Jessica Moore, ND,1Kulveen Virdee, ND,1Leah Albornoz-Sanchez, ND,1Michael Walker, ND,1Jami Cavins, ND,1Tonyelle Russell, ND,1Emily Guse, ND,1Mary Reker, ND,1Onyria Tschudy, ND,1Jeremy Wolf, ND,1Teresa True, ND,1Oluchi Ukaegbu, ND,1Ezenwanyi Ahaghotu, ND,1Ana Jones, ND,1Sara Polanco, ND,1Yvan Rochon, PhD,1,3Robert Waters, PhD,1,2and Jeffrey Langland, PhD1,2
Abstract
Background:Resurgences of Staphylococcus aureus infection continue globally, with antibiotic resistance increasing dramatically, making these infections more difficult to treat.S. aureus epidemics impose public health threats, and economic burdens on health care costs worldwide, presenting challenges modern medicine struggles to control.
Objective:In order to answer today’s call for effective treatments against S. aureus, we evaluated and compared various botanical extracts that have historically been suggested as useful for their antimicrobial properties against S. aureus.
Design:Briefly,S. aureus cultures were treated with selected botanical extracts and the minimum inhibitory concentration (MIC) determined. In addition, to obtain more quantitative measures on bacterial growth, 24-hour growth studies were done to examine the temporal activity and stability of various botanicals on bacterial replication.
Results:The antimicrobial activity observed for the botanical extracts used in this comparative evaluation of efficacy included both bacteriostatic and bacteriocidal activity against S. aureus. Highly effective botanicals including Salvia officinalis, Eucalyptus globulus,Coleus forskohlii,Coptis chinensis, Turnera diffusa, and Larrea tridentata exhibited MIC values ranging from 60 to 300lg/mL and a 106-fold reduction in bacterial replication.Arctostaphylos uva-ursi and Allium sativum were slightly less effective, exhibiting MIC values ranging from 90 to 400lg/mL and a 105-fold reduction, while Anemopsis californica gave MIC value of 360lg/mL and a 104-fold reduction in bacterial replication. Many botanicals, especially at lower doses, had an initial inhibitory effect followed by a recovery in bacterial replication. Such botanicals included E. globulus,C. chinensis,T. diffusa,A. californica, and Berberis vulgaris.
Conclusions:Our data demonstrate that S. officinalis, E. globulus, C. forskohlii, A. uva-ursi, C. chinensis,T. diffusa, A. californica, A. sativum,and L. tridentataall show promising direct antimicrobial activity against S. aureus.For many of these botanicals, strong bacteriocidal activity was observed at higher concentrations,but even at lower concentrations, bacteriostatic activity was evident. Other botanicals including B. vulgaris,Baptisia tinctoria, and Glycyrrhiza glabrashowed moderate activity against S. aureus, while Schisandra chinensis, Echinacea angustifolia, and Polygonum multiflorum were shown to be ineffective
Source : Journal Alternative and Complementary Medicine
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How zinc starves lethal bacteria to stop infection
Australian researchers have found that zinc can 'starve' one of the world's most deadly bacteria by preventing its uptake of an essential metal. The finding, by infectious disease researchers at the University of Adelaide and The University of Queensland, opens the way for further work to design antibacterial agents in the fight against Streptococcus pneumoniae.
Streptococcus pneumoniae is responsible for more than one million deaths a year, killing children, the elderly and other vulnerable people by causing pneumonia, meningitis, and other serious infectious diseases.
Published today in the journal Nature Chemical Biology, the researchers describe how zinc "jams shut" a protein transporter in the bacteria so that it cannot take up manganese, an essential metal that Streptococcus pneumoniae needs to be able to invade and cause disease in humans.
"It's long been known that zinc plays an important role in the body's ability to protect against bacterial infection, but this is the first time anyone has been able to show how zinc actually blocks an essential pathway causing the bacteria to starve," says project leader Dr Christopher McDevitt, Research Fellow in the University of Adelaide's Research Centre for Infectious Diseases.
"This work spans fields from chemistry and biochemistry to microbiology and immunology to see, at an atomic level of detail, how this transport protein is responsible for keeping the bacteria alive by scavenging one essential metal (manganese), but at the same time also makes the bacteria vulnerable to being killed by another metal (zinc)," says Professor Bostjan Kobe, Professor of Structural Biology at The University of Queensland.
The study reveals that the bacterial transporter (PsaBCA) uses a 'spring-hammer' mechanism to bind the metals. The difference in size between the two metals, manganese and zinc, causes the transporter to bind them in different ways. The smaller size of zinc means that when it binds to the transporter, the mechanism closes too tightly around the zinc, causing an essential spring in the protein to unwind too far, jamming it shut and blocking the transporter from being able to take up manganese.
"Without manganese, these bacteria can easily be cleared by the immune system," says Dr McDevitt. "For the first time, we understand how these types of transporters function. With this new information we can start to design the next generation of antibacterial agents to target and block these essential transporters."
Source : Science Daily
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_Antibacterial, antioxidant and phytochemical investigation of Thuja orientalis leaves
Nakuleshwar Dut Jasuja1*, Suresh K. Sharma2, Richa Saxena1, Jyoti Choudhary1, Ramavtar Sharma2 and Suresh C. Joshi3
1Department of Biotechnology and Allied Sciences, Jayoti Vidyapeeth Women’s University, Jharna, Jaipur -303007, Rajasthan, India.
2Department of Botany, University of Rajasthan, Jaipur, Rajasthan, India.
3Department of Zoology, University of Rajasthan, Jaipur, Rajasthan, India.
Abstract
In the present study, leaves of Thuja orientalis were powdered and extracted by soxhlet extractor in two solvent systems that is, (E1) ethyl acetate: chloroform: ethanol (40: 30: 30) and (E2) methanol: distilled water (70:30). This study conferred the screening of phytochemical constituents, antioxidant activity and antibacterial activity of crude E1 and E2 extract and its fractions. Antioxidant activity was carried out by 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. The results indicate that E2 extract (70% methanolic extract) had the highest antioxidant effect (85.25% inhibition) at 100 µg/ml concentration and the crude extracts (E1 and E2 extract) showed significant (P ≤ 0.05) inhibitory activity against both gram positive and gram negative organisms. It was active against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Agrobacterium tumefaiens. The minimum inhibitory concentrations (MICs) of E1 extract ranged from 0.40 to 0.85 mg/ml and E2 extract 0.55 to 1.15 mg/ml. The highest antibacterial potentiality was exhibited by E2 extract. The fractions also exhibited antimicrobial activity against all the selected microorganisms. The study revealed that T. orientalis is a promising phytomedicine for antioxidant and antibacterial activity.
Source : Journal of Medicinal Plant Research
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Antioxidant, antibacterial, antifungal activities and phytochemical analysis of dagger (Yucca aloifolia) leaves extracts
Sobia1, Muhammad Zubair1*, Nasir Rasool1, Asim Mansha1, Fozia Anjum1, Munawar Iqbal2, Muhammad Mushtaq2 and Muhammad Shahid1
1Department of Chemistry, Government College University, Faisalabad-38000, Pakistan.
2Department of Chemistry and Biochemistry, University of Agriculture, Faisalabad-38040, Pakistan.
Abstract
The leaves of Yucca aloifolia were extracted using methanol; fractions with organic solvents were analyzed for their biological activities and photochemical analysis. Total phenolic and flavonoid contents were determined using different colorimeteric assays. The antioxidant potential was evaluated by measuring reducing power, % inhibition of linoleic acid peroxide, and scavenging of 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical while antimicrobial and antifungal activities were evaluated by disc diffusion assay against a set of bacterial and fungal strains. Methanolic extract showed the superior yield of bioactive (%), total phenolics and total flavonoids, and phytochemical analysis revealed the presence of alkaloids, tannins, steroids, saponins and flavonoids. The Y. aloifolia leaves extract showed considerable antioxidant activity but were solvent-dependent. In biological assay, the extracts showed the antimicrobial activity comparable with standard antibiotics
Source : Journal of Medicinal Plant Research
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In vitro Antibacterial Activity of Aquatic Garlic Extract, Apple Vinegar and Apple Vinegar - Garlic Extract combination
Dr. Nada KhazalKadhim Hindi
Abstract
Background: Garlic (Allium sativum) has had an important dietary and medicinal role for centuries. It is a large annual plant of the Liliaceae family. Garlic is used in traditional medicine for infectious disease and some other cases.
Aims: The study aims at determining the antibacterial activity of of aquatic garlic extract, apple vinegar and apple vinegar - garlic extract combination against some bacterial isolates.
Methods: The antibacterial effects of aqueous garlic extract, apple vinegar, and apple vinegar- garlic extract combination against
9 Gram-positive and 5 Gram-negative bacterial isolates, including Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pyogenes, Enterococcus feacalis, Streptococcus pneumoniae, Pseudomonas aeruginosa, Pseudomonas fluresence, Enterobacter aerugenes, Klebsiella pneumoniae, Escherchia coli, Salmonella typhi, Proteus mirabilis, Proteus vulgaris, and Acinetobacter, all of them were studied.
Results: Antibacterial activity of aqueous garlic extract at 50% concentrations by well-diffusion method was characterized by
inhibition zones of 5 Gram-positive and 9 Gram-negative pathogenic bacteria. The maximum zone of inhibition of aqueous
garlic extract was observed in Salmonella typhi and the minimum was observed for Proteus sp. All organisms tested were highly
sensitive to apple vinegar- garlic extract combination, whereas all organisms tested were slightly sensitive to apple vinegar.
Conclusions: In summary, the aqueous garlic extract showed a wide spectrum activity and appears to satisfy all of the criteria
for antibacterial agents. These results suggest that garlic can be used to protect food and reduce the risk of contamination from
pathogenic microorganisms.
Source : American Journal of Phytomedicine and Clinical Therapeutics 2013; 1(1):42-51
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Garlic compound fights source of food-borne illness better than antibiotics
Researchers at Washington State University have found that a compound in garlic is 100 times more effective than two popular antibiotics at fighting the Campylobacter bacterium, one of the most common causes of intestinal illness. Their work was recently published in the Journal of Antimicrobial Chemotherapy.
The discovery opens the door to new treatments for raw and processed meats and food preparation surfaces.
"This work is very exciting to me because it shows that this compound has the potential to reduce disease-causing bacteria in the environment and in our food supply," says Dr. Xiaonan Lu, a postdoctoral researcher and lead author of the paper.
"This is the first step in developing or thinking about new intervention strategies," says Michael Konkel, a co-author who has been researching Campylobacter jejuni for 25 years.
"Campylobacter", says Konkel, "is simply the most common bacterial cause of food-borne illness in the United States and probably the world." Some 2.4 million Americans are affected every year, according to the Centers for Disease Control and Prevention, with symptoms including diarrhea, cramping, abdominal pain and fever. The bacteria are also responsible for triggering nearly one-third of the cases of a rare paralyzing disorder known as Guillain-Barré syndrome.
Most infections stem from eating raw or undercooked poultry or foods that have been cross-contaminated via surfaces or utensils used to prepare poultry.
Lu and his colleagues looked at the ability of the garlic-derived compound, diallyl sulfide, to kill the bacterium when it is protected by a slimy biofilm that makes it 1,000 times more resistant to antibiotics than the free floating bacterial cell. They found the compound can easily penetrate the protective biofilm and kill bacterial cells by combining with a sulfur-containing enzyme, subsequently changing the enzyme's function and effectively shutting down cell metabolism.
The researchers found the diallyl sulfide was as effective as 100 times as much of the antibiotics erythromycin and ciprofloxacin and would often work in a fraction of the time.
Two previous works published last year by Lu and WSU colleagues in Applied and Environmental Microbiology and Analytical Chemistry found diallyl sulfide and other organosulfur compounds effectively kill important foodborne pathogens, such as Listeria monocytogenes and Escherichia coli O157:H7.
Konkel cautions that the recent work is still at the basic stage, well removed from an actual application. While eating garlic is a generally healthy practice, it is unlikely to prevent Campylobacter-related food poisoning. However, "diallyl sulfide may be useful in reducing the levels of the Campylobacter in the environment and to clean industrial food processing equipment, as the bacterium is found in a biofilm in both settings."
"Diallyl sulfide could make many foods safer to eat", says Barbara Rasco, a co-author on all three recent papers and Lu's advisor for his doctorate in food science. "It can be used to clean food preparation surfaces and as a preservative in packaged foods like potato and pasta salads, coleslaw and deli meats".
"This would not only extend shelf life but it would also reduce the growth of potentially bad bacteria," she says.
Source : MedicalXpress
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Antibacterial Activity of the Extracts Obtained from Rosmarinus officinalis, Origanum majorana, and Trigonella foenum-graecum on Highly Drug-Resistant Gram Negative Bacilli
(Rosemary, Marjoram, Fenugreek)
Abstract
Our aim was to determine the antimicrobial activity of three selected plants (Rosmarinus officinalis, Origanum majorana, and Trigonella foenum-graecum) against Extended Spectrum Beta Lactamase (ESBL)—producing Escherichia coli and Klebsiella pneumoniae--
and to identify the specific plant fraction responsible for the antimicrobial activity. The plants were extracted with ethanol to yield the crude extract which was further subfractionated by different solvents to obtain the petroleum ether, the dichloromethane, the ethyl acetate, and the aqueous fractions. The Minimum Inhibitory Concentrations (MIC) and Minimum Bactericidal Concentrations (MBC) were determined using broth microdilution. The MICs ranged between 1.25 and 80 𝜇g/𝜇l. The majority of these microorganisms were inhibited by 80 and 40 𝜇g/𝜇l of the crude extracts. The petroleum ether fraction of Origanum majorana significantly inhibited 94% of the tested strains. Ethyl acetate extracts of all selected plants exhibited relatively low MICs and could be therefore described as strong antibacterial.
Source : Bontany Journal
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Antimicrobial activity of essential oil extract of Ocimum basilicum L. leaves on a variety of pathogenic bacteria
(Basil)
Abstract
As in the recent years the usage of the herbal materials has been increased, it seems necessary to study the antibacterial effects of them. The basil herb, which is easily cultured worldwide, may be a potentially good candidate to be used as a plant with antibacterial activity. The essential oil was distilled using a Clevenger-type apparatus and extracted from plant leaves. The antibacterial properties of basil essential oil was studied on the standard gram-negative bacteria including Escherichia coli, Pseudomonas aeruginosa, and gram-positive ones including Bacillus cereus, Staphylococcus aureus, then agar disk diffusion, minimal inhibition concentration (MIC) and minimum bactericidal concentration (MBC) were detected. The results of agar disk diffusion tests showed the inhibition zones
as follow: S. aureus 29.20-30.56 mm, B. cereus 10.66-16.11 mm, E. coli 17.48-23.58 mm and for P. aeruginosa the maximum inhibition zones were seen. The results of this study showed the presence of bacteriostatic effects of basil essential oil on all the test bacteria. The MICs for gram-positive bacteria
were as: B. cereus ranging 36-18 μg/mL, S. aureus 18 μg/mL, and for Gram-negative bacteria of E. coli and P. aeruginosa were 18-9 μg/mL.
Source : Journal of Medicinal Plants Research Vol. 5(15), pp. 3453-3456, 4 August, 2011
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A review of chemistry and bioactivities of a medicinal spice: Foeniculum vulgare
(Fennel)
Fennel has been used as food and medicine with long history in central Europe and Mediterranean region as well as in China. It is also a flavor food with health value. Numerous compounds including trans-anethole, estragole, fenchone, sesquiterpenoids, coumarins and polyphenolics were isolated from this plant, most of which exhibited significant bioactivities. The fennel has potential beneficial therapeutic actions in the management of bacterial and fungal infections and colic pain. Both the fruit and whole plant of this plant might be the source of chemical and biological materials in future. For further utilization of this plant, systematic phytochemical and biological mechanic studies are needed.
Source : Journal of Medicinal Plants Research Vol. 5(16), pp. 3595-3600, 18 August, 2011
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