• Biomolecules & Therapeutics
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• v.1 no.2
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• pp.177-182
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• 1993

From 84 clinical isolates of Staphylococcus species, ten strains showing inducible resistance to MLS antibiotics were selected by disk agar diffusion method. Colony hybridization was executed using two MLS inducible resistance genes, ermA and ermC, previously identified from S. aureus as probes. S. hemolyticus 401 and S. epidermidis 542 whose genes were not homologous to those probes were finally selected. It was determined that the resistance genes of S. hemolyticus 401 and S. epidermidis 542 were not homologous to ermA, ermC and ermAM by Southern hybridization. S. epidermidis 542 had a plasmid DNA. To know if the plasmid may have genes related to inducible resistance, it was attempted to transform B. subtilis BR151 and S. aureus RN4220 with the plasmid prepared from S. epidermidis 542. It was shown that the gene related to inducible resistance to MLS antibiotics did not exist in this plasmid. These results indicate that two clinical isolates of S. hemolyticus 401 and S. epidermidis 542 had novel genes which were not homologous to MLS resistance genes identified previously. It was assumed that these genes may exist in chromosomal DNA.

• Applied Biological Chemistry
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• v.41 no.8
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• pp.605-607
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• 1998

A total of 28 traditional drinks derived from 23 plant species in 19 families were tested for their in vitro growth-inhibiting effects against Bifidobacterium adolescents, Bifidobacterium bifidum, Lactobacillus acidophilus, Lactobacillus casei, Clostridium perfringens, and Escherichia coil using a paper disc agar diffusion method under anaerobic condition. The responses varied with bacterial strain, plant species and tissue sampled. In a test with C. perfringens at 5 and 10 mg/disc, potent growth inhibition was produced from the extracts of Eucommia ulmoides stems, Pinus densiflora leaves and shoots, Thea sinensis leaves (green and oolong teas) and Zingiber officinale roots. All materials tested did not adversely affect the growth of bifidobacteria, lactobacilli, and E. coli. These results may be an indication of at least one of the pharmacological activities of these plant-derived drinks.

• Journal of Microbiology and Biotechnology
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• v.20 no.1
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• pp.161-168
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• 2010

In this study, the metabolic activities of five strains of Pediococcus spp., in terms of the quantities they produced of lactic acid, hydrogen peroxide, exopolysaccharides, and proteolytic activity, were determined. Lactic acid levels produced by these strains were found to be in the range of 2.5-5.6 mg/ml. All strains produced hydrogen peroxide. The P. pentosaceus Z13P strain produced the maximum amount (0.25 mg/ml) of proteolytic activity. Exopolysaccharide (EPS) production by the Pediococcus strains during growth in MRS (de Man, Rogosa, and Sharpe) medium was in the range 25-64 mg/l. The susceptibility of 10 different antibiotics against these strains was also tested. All strains were found to be resistant to amoxicillin, gentamicin, and vancomycin. Antimicrobial effects of the Pediococcus spp. on pathogens were also determined by an agar diffusion method. All of the strains were able to inhibit L. monocytogenes. The tolerance of the strains to low pH, their resistance to bile salts of strains, and their abilities to autoaggregate and coaggregate with L. monocytogenes were also evaluated.

• Advances in Traditional Medicine
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• v.8 no.4
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• pp.395-399
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• 2008

Methanol and aqueous extract of leaves of Trema orientalis Linn. were subjected to the potential antioxidant and antibacterial activities. The pharmacological interest of this plant coupled with traditional use (antidiarrhoeal, antiseptic, analgesic etc) prompted to test for antioxidant and antibacterial activities. The antioxidant potential of the methanolic extract was determined on the basis of their scavenging activity of the stable 1,1-diphenyl-2-picryl hydrazyl free radical. $IC_{50}$ of the methanol extract of T. orientalis was $110.25\;{\mu}g/ml$ which indicated the strong antioxidant activity of the plant. However the aqueous extract showed mild antioxidant activity. In case of antibacterial activities test, the extract was subjected for its effectiveness against both Gram-positive and Gram-negative bacteria in agar diffusion method. The zones of inhibition produced by the crude methanol and aqueous extract against few sensitive strains were measured and compared with those of standard antibiotic Gentamycin. It is evident that both extracts are active against the bacteria at low concentrations. The obtained results provide a support for the use of this plant in traditional medicine and suggest its further advance investigation.

• Journal of Dairy Science and Biotechnology
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• v.38 no.1
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• pp.53-57
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• 2020

Culture concentrate of probiotic Lactobacillus johnsonii PF01 inhibited the growth of Staphylococcus aureus, which was confirmed by agar well diffusion method. Protease treatment of PF01 culture concentrate indicated that the antimicrobial substance of PF01 was a bacteriocin. Investigation of PF01 genome revealed the existence of a gene similar to that of helveticin, which showed 34.9% and 41.0% identity with those of L. helveticus 481 and L. crispatus K313, respectively, thereby suggesting that the bacteriocin produced by strain PF01 is a helveticin homolog.

• CELLMED
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• v.2 no.4
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• pp.37.1-37.4
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• 2012

In the present study, the volatile oil, chloroform extract and methanol extract of the woods of the plants Cedrus deodara and Pinus roxburghii were screened for their antibacterial and antifungal activities against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus subtilis, Streptococcus pyogenes, Candida albicans, Aspergillus niger, and Aspergillus clavatus using the Agar diffusion method. The susceptibilities of the microorganisms to the extracts were compared with each other and with a selected standard antibiotic. It was observed that the volatile oil and chloroform extracts showed the significant antibacterial activities while the least antibacterial activity was recorded with the methanolic extracts. The higher Minimum Inhibitory Concentration value of the extracts and oils against fungus suggested that the plants may possess less antifungal activity. Phytochemical analysis and thin-layer chromatography profiling revealed the presence of flavonoids and terpenoids in the oil and chloroform extracts, which could explain the antimicrobial activity. The findings suggest that the Cedrus deodara and Pinus roxburghii have antimicrobial properties and they can be used in the treatment of infectious diseases. However, further work is required in order to isolate the active constituents of the plants responsible for the antibacterial activity.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.45 no.6
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• pp.600-605
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• 2012

In this study, we investigated the mechanism of inhibition of pathogenic bacteria by Pediococcus pentosaceus strain SH-10 isolated from hard Clam Meretrix meretrix sikhae. When P. pentosaceus SH-10 was co-cultured in MRS broth with pathogenic bacteria, including Bacillus cereus, Listeria monocytogenes, Salmonella choleraesuis and Staphyloccus aureus, no viable pathogenic cells were detected after 18 h of incubation. However, pediocin or a pediocin-like bacteriocin was not detected in cultures of P. pentosaceus SH-10 by the agar diffusion method. Organic acids were produced in MRS broth in proportion to the incubation time of P. pentosaceus SH-10. These results indicate that P. pentosaceus SH-10 inhibited the growth of pathogenic bacteria by lowering the pH of the growth medium through the production of organic acids, including sodium lactate, sodium acetate, and sodium citrate.

• Natural Product Sciences
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• v.20 no.3
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• pp.152-159
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• 2014

A phytochemical investigation of Spergularia marina (L.) Griseb. growing in Egypt, has been carried out, which resulted in the isolation of seven compounds from the different extracts of the plant namely; ${\beta}$-sitosterol glucoside, tricin (1) dihydroferulic acid (2), vanillic acid (3), 4-hydroxybenzoic acid (4), uracil (5) and 8-hydroxy cuminoic acid (6) Structure elucidation of the isolated compounds was carried out using different spectroscopic techniques. This is the first report for the isolation of these compounds from genus Spergularia. Furthermore, 8-Hydroxy cuminoic acid and uracil were isolated for the first time from family Caryophyllaceae. The chemical composition of the volatile components present in the petroleum ether extract of Spergularia marina (L.) Griseb. using combined gas chromatography-mass spectrometry (GC-MS) is reported here for the first time. Of the 97 components present, 59 were identified including three sulfur containing compounds which represented about 1.8% of the volatiles of the total petroleum ether extract. This prompted us to study and report its possible antimicrobial activity. In addition, the antibacterial and antifungal screening of different extracts of Spergularia marina (L.) Griseb. as well as some isolates have been performed using agar diffusion method.

• Korean Journal of Microbiology
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• v.37 no.4
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• pp.299-304
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• 2001

Teicoplanin is a kind of glycopeptide antibiotics produced by Actinoplanes teichomyceticus, and used in the clinical antibiotic such as vancomycin against methicillin-resistant Stabphylococcus aureus (MRSA). Actino planes teichomyceticus ATCC 31121 was mutated with UV to obtain a superior mutant strain with increased level of teicoplanin production. In this investigation, lethal curve was obtained and the optimal condition to induce mutagenesis was determined to isolate the desirable mutant strain. It was also confirmed that teicoplanin activities by agar diffusion method was compared with the parent strain. One mutant strain, T991014-1 with the highest productivity, was finally selected, and was characterized through the various tests such as amylase activity, protease activity, halotolerance, antibiotic resistance, autotoxicity, and productivity. Ad fermentation characteristics of the mutant strain were also studied.

• Journal of Microbiology
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• v.45 no.1
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• pp.53-57
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• 2007

A number of essential oils from Mongolian aromatic plants are claimed to have antimicrobial activities. The essential oil of Dracocephalum foetidum, a popular essential oil used in Mongolian traditional medicine, was examined for its antimicrobial activity. Eight human pathogenic microorganisms including B. subtilis, S. aureus, M. lutens, E. hirae, S. mutans, E. coli, C. albicans, and S. cerevisiae were examined. The essential oil of Dracocephalum foetidum exhibited strong antimicrobial activity against most of the pathogenic bacteria and yeast strains that were tested; by both the agar diffusion method and the minimum inhibitory concentration (MIC) assay ($MIC\;range\;was\;26-2592{\mu}g/ml$). Interestingly, Dracocephalum foetidum even showed antimicrobial activity against methicilin-resistant Staphylococcus aureus (MRSA) strains. We also analyzed the chemical composition of the oil by GC-MS and identified several major components, including n-Mentha-1,8-dien-10-al, limonene, geranial, and neral.