The objective of this study is to evaluate the antimicrobial activity of D. scandens aqueous extract against various bacteria. The stems of D. scandens were extracted using aqueous extraction with yield 1.5-2% of dried weight of plant stems. The antimicrobial activity was screened by using agar diffusion method. Minimum Inhibitory Concentrations (MICs) and MBCs values were determined using agar dilution method and broth macro-dilution method. The agar diffusion tested revealed that the plant aqueous extract showed inhibition zone against S. aureus ATCC 25923, S. epidermidis ATCC 12228 and E. coli ATCC 25922. Among three bacteria, S. aureus and S. epidermidis is gram positive bacteria, while E. coli is gram negative bacteria. Minimum Bactericial Concentration (MICs) of the plant aqueous extract were in range of 2-4 g L-1, while MBCs were in the range of 4-16 g L-1. In conclusion, the plant extract showed good inhibitory effect on growth of S. aureus and E. coli which are nosocomial infection bacteria and those S. epidermidis which is normal flora.
Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.
[Show abstract][Hide abstract] ABSTRACT: The use of natural compounds from plants can provide an alternative approach against food-borne pathogens. The mechanisms
of action of most plant extracts with antimicrobial activity have been poorly studied. In this work, changes in membrane integrity,
membrane potential, internal pH (pHin), and ATP synthesis were measured in Vibrio cholerae cells after exposure to extracts of edible and medicinal plants. A preliminary screen of methanolic, ethanolic, and aqueous
extracts of medicinal and edible plants was performed. Minimal bactericidal concentrations (MBCs) were measured for extracts
showing high antimicrobial activity. Our results indicate that methanolic extracts of basil (Ocimum basilicum L.), nopal cactus (Opuntia ficus-indica var. Villanueva L.), sweet acacia (Acacia farnesiana L.), and white sagebrush (Artemisia ludoviciana Nutt.) are the most active against V. cholera, with MBCs ranging from 0.5 to 3.0 mg/ml. Using four fluorogenic techniques, we studied the membrane integrity of V. cholerae cells after exposure to these four extracts. Extracts from these plants were able to disrupt the cell membranes of V. cholerae cells, causing increased membrane permeability, a clear decrease in cytoplasmic pH, cell membrane hyperpolarization, and
a decrease in cellular ATP concentration in all strains tested. These four plant extracts could be studied as future alternatives
to control V. cholerae contamination in foods and the diseases associated with this microorganism.
Full-text · Article · Oct 2010 · Applied and Environmental Microbiology
[Show abstract][Hide abstract] ABSTRACT: Respiratory system is the primary settlement place of opportunistic organisms and considered as chief carrier of common respiratory pathogens. The aim of the study was to know the opportunistic organisms present in the healthy subjects as well as subjects that were suffering from respiratory symptoms. The organisms were identified as per standard bacteriological protocol and pathogenicity tests of the identified organisms were performed in mouse model. Antibiotic sensitivity of the identified organisms was performed. The bacterial flora present in the throat swab of apparently healthy as well as subjects suffering from respiratory symptoms were: Staphylococcus spp. (39.44%) of which Coagulase positive Staphylococcus (21.13%) and Coagulase negative Staphylococcus (18.31%), Klebsiella spp. (19.72%), Pseudomonas spp. (15.49%), Proteus spp. (4.23%), E. coli (9.86%) and Bacillus spp. (11.27%). Among the isolates Staphylococcus, Klebsiella and Pseudomonas were the predominant species. Percentages of identified bacteria were higher in respiratory symptoms exhibiting individuals (53.52%) than apparently healthy individuals (46.48%). All coagulase positive Staphylococcus, Klebsiella spp. and Pseudomonas spp. isolated from respiratory symptoms' subjects were found to be pathogenic. The isolated bacteria were resistant to amoxicillin and ampicillin but sensitive to ciprofloxacin and norfloxacin. Isolated Pseudomonas spp. showed multidrugs resistant properties. The study provided information about the pathogenic organisms' present respiratory systems of apparently healthy as well as subjects suffering from respiratory symptoms. The pathogenic natures of the isolated organisms were determined to make aware of scientists as well as clinicians. Antibiotics sensitivity assays would provide information to the clinicians for the selection of appropriate antibiotics to treat their patients.
[Show abstract][Hide abstract] ABSTRACT: The chemical composition of the volatile extract (yield ≈ 0.13%, v/w) from the bark of Quercus leucotrichophora (Fagaceae) was analysed for the first time by GC-MS. Twenty-three constituents, amounting to 93.0% of the total detected contents of the volatile extract, were identified. The volatile extract contained approximately 86.36% monoterpenoids, 6.53% sesquiterpenoids and 0.11% aliphatic aldehydes. 1,8-Cineol (40.359%) followed by γ-terpinene (16.369%) were the major monoterpene constituents of the volatile extract. The residue of volatile extract (0.00025-250 µg mL(-1)) exhibited a potent antimicrobial activity against Streptococcus pyogenes ATCC 19615. This study concludes that residues of the volatile extract of Q. leucotrichophora could serve as an important bioresource for the extraction and isolation of monoterpenoids exhibiting antimicrobial activity, and thus has good potential for use in the pharmaceutical industry.
No preview · Article · Sep 2011 · Natural product research