Antimicrobial property of lemongrass (Cymbopogon citratus) oil against pathogenic bacteria isolated from pet turtles / 한국실험동물학회지

The usage of essential oils as antimicrobial agents is gaining attention. Besides, pet turtles were known to harbor a range of pathogenic bacteria while the turtle keeping is a growing trend worldwide.The current study examined the antimicrobial activity of lemon grass oil (LGO) against seven species of Gram negative bacteria namely; Aeromonas hydrophila, A. caviae, Citrobacter freundii, Salmonella enterica, Edwardsiella tarda, Pseudomonas aeruginosa, and Proteus mirabilis isolated from three popular species of pet turtles. Along with the results of disc diffusion, minimum inhibitory and minimum bactericidal concentration (MIC and MBC) tests, LGO was detected as effective against 6 species of bacteria excluding P. aeruginosa. MIC of LGO for the strains except P. aeruginosa ranged from 0.016 to 0.5% (V/V). The lowest MIC recorded in the E. tarda strain followed by A. hydrophilla, C. freundii, P. mirabilis, and S. enterica. Interestingly, all the bacterial species except E. tarda were showing high multiple antimicrobial resistance (MAR) index values ranging from 0.36 to 0.91 upon the 11 antibiotics tested although they were sensitive to LGO.

Pyrimidinethione derivatives with tosyl substitution: Synthesis, and antimicrobial property investigation.

Substitution of tosyl group on hydroxyacetophenones orhydroxybenzaldehyde and their subsequent condensation yielded several tosyloxy substituted chalcones which were derivatized to obtain the corresponding pyrimidinethione derivatives. The synthesized compounds were characterized by spectroscopic techniques like FT-IR, 1H NMR, 13C NMR, and mass spectrometry. These compounds were subjected to initial screening for their bioactivity using zone of inhibition method and were found moderately active against the tested microorganisms, viz. Mycobacterium smegmatis, Staphylococcus aureus, Escherichia coli, and Candida albicans.

Antimicrobial properties of Ethiopian chewing sticks against Candida albicans.

Ethnobotanical survey was done in Jimma, Ethiopia, to identify the plants used for oral hygiene and evaluate the same against a selected oral pathogen. The survey revealed the use of chewing sticks to manage oral hygiene/infection. In spite of their wide use, very little has been done to evaluate their antimicrobial activity. Hence 11 chewing stick plants were chosen for antimicrobial study against an oral pathogen – Candida albicans the causative organism for oral candidiasis by agar well diffusion (Perez, 1991). The results revealed that Olea europaea extract showed maximum inhibition on its own. The activity of Justicia schimperiana was increased to three fold when combined with cinnamon and brown honey. The research documents the use of chewing sticks to manage oral infection caused by Candida albicans, which will be of immense assistance to developing countries with financial constraints and limited health care facilities.

Antimicrobial Activity of Aloevera barbedensis, Daucus carota, Emblica officinalis, Honey and Punica granatum and Formulation of a Health Drink and Salad

Aims: Indian folk medicine has been in practice from time immemorial. Traditional medicine interconnects our body with nature for a healthy living. The naturally occurring antimicrobials in food vary in their efficacy and function, toxicology, safety and mechanism of action against microorganisms. Methodology and Results: The study revitalizes the traditional system of medicine in order to achieve self reliance in health care and health for all by analyzing the antimicrobial property of aqueous extracts of aloevera (Aloevera barbedensis), carrot (Daucus carota), Indian gooseberry (Emblica officinalis), honey and pomegranate (Punica granatum), and to assess the reason for inhibition of growth of pathogenic organisms by DNA and protein analysis. Various aqueous extracts showed inhibition to microrganisms like Escherichia coli, Pseudomonas aeruginosa, Salmonella typhi, Shigella flexineri and Staphylococcus aureus. Conclusion significance and impact of study: The study also formulated and standardized a nourishing health drink and salad using the tested foods and estimated their shelf life and nutritive value. The health drink and salad had a low protein, low fat and moderate carbohydrate content. Therapeutically this drink and salad can be used to treat obesity.

Evaluation of antimicrobial properties of four plant extracts against human pathogens

Objective: To investigate the antibacterial activity of the extracts of Alternanthera philoxeroides (A. philoxeroides), Plumeria obtusa (P. obtusa), Polyalthia cerasoides (P. cerasoides) and Ixoraacuminate (I. acuminate) against human pathogens. Methods: Aqueous and chloroform: methanol (1:1) extracts of the dried leaf of A. philoxeroides, flowers of P. obtusa, fruits of P. cerasoides and flowers of I. acuminate were tested in vitro by the disk diffusion method against four bacterial strains, namely, Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Pseudomonasaeruginosa. Susceptibility of four reference bacterial strains to some antibiotics in nutrient agar was also tested. Minimal inhibitory concentration (MIC) values were determined and qualitative phytochemical analysis of the crude extract of the tested plant parts was done. Results: Both the aqueous and the chloroform: methanol (1:1) extracts of P. cerasoides showed the strongest activity, followed by flowers of P. obtusa, leaves of A. philoxeroides and flowers of I. acuminate. Aqueous extracts of all the plant parts appeared to have less antibacterial activity than the chloroform:methanol (1:1) extracts. The result of phytochemical analysis of the crude extract of the tested plants showed that flavonoid was absent from all plant parts whereas steroid was present in all tested plant parts. Conclusions: The results support that these plant extracts can be used for the treatment of bacterial diseases.

Honey: its medicinal property and antibacterial activity

Indeed, medicinal importance of honey has been documented in the world's oldest medical literatures, and since the ancient times, it has been known to possess antimicrobial property as well as wound-healing activity. The healing property of honey is due to the fact that it offers antibacterial activity, maintains a moist wound condition, and its high viscosity helps to provide a protective barrier to prevent infection. Its immunomodulatory property is relevant to wound repair too. The antimicrobial activity in most honeys is due to the enzymatic production of hydrogen peroxide. However, another kind of honey, called non-peroxide honey (viz., manuka honey), displays significant antibacterial effects even when the hydrogen peroxide activity is blocked. Its mechanism may be related to the low pH level of honey and its high sugar content (high osmolarity) that is enough to hinder the growth of microbes. The medical grade honeys have potent in vitro bactericidal activity against antibiotic-resistant bacteria causing several life-threatening infections to humans. But, there is a large variation in the antimicrobial activity of some natural honeys, which is due to spatial and temporal variation in sources of nectar. Thus, identification and characterization of the active principle(s) may provide valuable information on the quality and possible therapeutic potential of honeys (against several health disorders of humans), and hence we discussed the medicinal property of honeys with emphasis on their antibacterial activities.

Honey：its medicinal property and antibacterial activity

Indeed, medicinal importance of honey has been documented in the world's oldest medical literatures, and since the ancient times, it has been known to possess antimicrobial property as well as wound-healing activity. The healing property of honey is due to the fact that it offers antibacterial activity, maintains a moist wound condition, and its high viscosity helps to provide a protective barrier to prevent infection. Its immunomodulatory property is relevant to wound repair too. The antimicrobial activity in most honeys is due to the enzymatic production of hydrogen peroxide. However, another kind of honey, called non-peroxide honey (viz., manuka honey), displays significant antibacterial effects even when the hydrogen peroxide activity is blocked. Its mechanism may be related to the low pH level of honey and its high sugar content (high osmolarity) that is enough to hinder the growth of microbes. The medical grade honeys have potentin vitrobactericidal activity against antibiotic-resistant bacteria causing several life-threatening infections to humans. But, there is a large variation in the antimicrobial activity of some natural honeys, which is due to spatial and temporal variation in sources of nectar. Thus, identification and characterization of the active principle(s) may provide valuable information on the quality and possible therapeutic potential of honeys (against several health disorders of humans), and hence we discussed the medicinal property of honeys with emphasis on their antibacterial activities.

Evaluation of multiple plant growth promoting traits of an isolate of Pseudomonas fluorescens strain Psd.

P. fluorescens strain Psd was isolated from the rhizosphere of Vigna mungo and evaluated for its multiple plant growth promoting and biocontrol properties against F. oxysporum. Interestingly, this strain not only produces a range of antimicrobial compounds but also solubilizes complexed phosphates and synthesizes phytohormone (IAA). These properties can be assessed to elucidate the agronomic significance and rhizospheric competence of this soil isolate. Biocontrol action has been demonstrated in vitro against some other rhizospheric bacteria, and a phytopathogenic fungus along with wild type E. coli K-12. Genetic evidence for the antimicrobial status of strain Psd has been derived in terms of elucidating a unique combination of phenazine and pyrrolnitrin biosynthesis genes, not reported for any other P. fluorescens strain. The conserved part of antibiotics biosynthesis operon has been PCR amplified, cloned, sequenced and phylogenetic relationship based on similar genes from a few known Pseudomonads has been derived. The properties possessed by strain Psd may enable the bacterium to establish itself successfully in the rhizosphere.

Antimicrobial activity of leaf extracts of Senna obtusifolia (L)

Antimicrobial properties of leaf extracts of Senna obtusifolia (L) were investigated against both clinical and laboratory isolates of both bacteria and fungi using the disc diffusion method. Acetone extracts (12 mm zone diameter of inhibition, MIC 200 g/mL and MBC 300 g/mL) demonstrated the highest activity, followed by dichloromethane (8 mm zone diameter of inhibition, MIC 300 g/mL and MBC 400 g/mL), methane (7 mm zone diameter of inhibition, MIC 400 g/mL and MBC 400 g/mL) and hexane (6 mm zone diameter of inhibition, MIC 800 g/mL and MBC 1000 g/mL). Water extracts demonstrated the least activity against the test bacteria and fungi (4 mm zone diameter of inhibition, MIC 800 g/mL and MBC 800 g/mL). Phytotoconstituents present included Saponins, Tannins, Alkaloids and Flavonoids. S. obtusifolia (L) can be used to source antibiotic substances for possible treatment of bacterial and fungal infections including gonorrhea, pneumonia, urinary tract and some mycotic infections