• Journal of Microbiology and Biotechnology
• /
• v.28 no.9
• /
• pp.1563-1572
• /
• 2018

Gold nanoparticles (AuNP) and their conjugates have been gaining a great deal of recognition in the medical field. Meanwhile, extended-spectrum ${\beta}$-lactamases (ESBL)-producing bacteria are also demonstrating a challenging problem for health care. The aim of this study was the biosynthesis of AuNP using Rosa damascenes petal extract and conjugation of ceftriaxone antibiotic (Cef-AuNP) in inhibiting ESBL-producing bacteria and study of in vitro anticancer activity. Characterization of the synthesized AuNP and Cef-AuNP was studied. ESBL-producing strains, Acinetobacter baumannii ACI1 and Pseudomonas aeruginosa PSE4 were used for testing the efficacy of Cef-AuNP. The cells of MCF-7 breast cancer were treated with previous AuNP and Cef-AuNP at different time intervals. Cytotoxicity effects of apoptosis and its molecular mechanism were evaluated. Ultraviolet-visible spectroscopy and Fourier transform infrared spectroscopy established the formation of AuNP and Cef-AuNP. Transmission electron microscope demonstrated that the formed nanoparticles were of different shapes with sizes of 15~35 nm and conjugation was established by a slight increase in size. Minimum inhibitory concentration (MIC) values of Cef-AuNP against tested strains were obtained as 3.6 and $4{\mu}g/ml$, respectively. Cef-AuNP demonstrated a decrease in the MIC of ceftriaxone down to more than 27 folds on the studied strains. The biosynthesized AuNP displayed apoptotic and time-dependent cytotoxic effects in the cells of MCF-7 at a concentration of $0.1{\mu}g/ml$ medium. The Cef-AuNP have low significant effects on MCF-7 cells. These results enhance the conjugating utility in old unresponsive ceftriaxone with AuNP to restore its efficiency against otherwise resistant bacterial pathogens. Additionally, AuNP may be used as an alternative chemotherapeutic treatment of MCF-7 cancer cells.

• Journal of Microbiology and Biotechnology
• /
• v.20 no.2
• /
• pp.311-318
• /
• 2010

Antimicrobial finishing of textiles has been found to be an economical way to prevent (or treat) skin disorders. Hence, this research effort was aimed at elucidating the relationship between the molecular weight (MW) of chitosan and its antimicrobial activity upon six dermal reference microorganisms, as well as the influence of the interactions with cotton fabrics on said activity. Using 3 chitosans with different MWs, as well as two chitooligosaccharide (COS) mixtures, a relevant antimicrobial effect was observed by 24 h for the six microorganisms tested; it was apparent that the antimicrobial effect is strongly dependent on the type of target microorganism and on the MW of chitosan - being higher for lower MW in the case of E. coli, K. pneumoniae, and P. aeruginosa, and the reverse in the case of both Gram-positive bacteria. Furthermore, a strong antifungal effect was detectable upon C. albicans, resembling the action over Gram-positive bacteria. Interactions with cotton fabric resulted in a loss of COS activity when compared with cultured media, relative to the effect over Gram-negative bacteria. However, no significant differences for the efficacy of all the 5 compounds were observed by 4 h. The three chitosans possessed a higher antimicrobial activity when impregnated onto the fabric, and presented a similar effect on both Gram-positive bacteria and yeast, in either matrix. Pseudomonas aeruginosa showed to be the most resistant microorganism to all five compounds.

• Korean Journal of Veterinary Research
• /
• v.51 no.1
• /
• pp.29-35
• /
• 2011

Lack of hygiene and puerperal mastitis are common causes of bacterial diseases in nursing neonates. The aim of this study was to isolate microorganisms from milk samples of healthy female Jindo dogs with suckling puppies and to investigate antimicrobial susceptibility against the isolated bacteria. Milk samples were collected from 120 udders of 12 lactating Jindo dogs that were 2~4 years old without any clinical diseases including mastitis. Bacteria were isolated from 64 milk samples (53.3%), either singly (76.6%) or in combination (23.4%). Staphylococcus (S.) spp. was the most common microorganisms (74.7%) isolated from canine milk, followed by Haemophillus spp. (10.9%), Streptococcus spp. (9.6%), Gardnerella spp. (2.4%) and Moraxella spp. (2.4%). The most frequently isolated organism was S. warneri (31.3%). Antimicrobial susceptibility of these bacteria was tested with 17 antimicrobial agents by Kirbyand Bauer standardized disc diffusion method. Results indicated that bacteria isolated from healthy canine milk were mostly susceptible to amoxicillin-clavulanic acid, cephalothin and ceftiofur, but were resistant to erythromycin, neomycin and tetracycline.

• Journal of Environmental Health Sciences
• /
• v.40 no.4
• /
• pp.304-312
• /
• 2014

Objectives: This study was performed to examine bioaerosols in indoor air in public restrooms, as well as to assess the effects of air temperature and relative humidity on bioaerosol levels. Methods: A cross-sectional survey was performed in ten male and ten female restrooms. An air sampler (Anderson type) was used for sampling total suspended bacteria (TSB), Gram-negative bacteria (GNB), Gram-positive bacteria (GPB), opportunistic bacteria (OP), Staphylococcus spp., and total suspended fungi (TSF). Results: The levels of TSB were $10-10^2CFU/m^3$ and TSF $10-10^2CFU/m^3$, respectively. The GNB level was $0-10CFU/m^3$, and GPB and OP levels were $10-10^2CFU/m^3$. Staphylococcus aureus and methicillin-resistant S. aureus (MRSA) were detected in 90% of the restrooms. The GPB level was higher in the female restrooms than in the male restrooms (p < 0.05). TSB, GNB, and TSF showed higher levels in restrooms in buildings over 30 years old (p < 0.01). The main effect of air temperature or relative humidity and interaction effect of the two factors on the TSB level were significant (p < 0.05), while the effect of relative humidity on the TSF level was significant (p < 0.001). Conclusions: These results indicate that there is a wide variation in the bioaerosol levels among different restrooms. The observed differences in bioaerosol levels reflect different building histories. The effects of air temperature and/or relative humidity reveal that bioaerosol levels may vary according to season or time of day. Future research is needed to further characterize the relation between the bioaerosol levels and surface contamination in restrooms.

• Journal of Dairy Science and Biotechnology
• /
• v.31 no.1
• /
• pp.51-58
• /
• 2013

Emerging studies suggest that vegetables or fruit juices deemed to be potential alternative base medium for lactic acid bacteria fermentation. Until now, limited studies have been carried out to evaluate such applications. Thus, the objective of present study is that lactic acid bacteria were evaluated for their viability at low pH, growth during storage at low temperature, and $CO_2$ formation. Furthermore, the effects of grapefruit extract with respect to cell viability, sensory ability, and organic acid production were evaluated for these strains. The probiotic properties of the strains, including acid tolerance, bile tolerance, and adhesion to human intestinal epithelial cells (HT-29 cells), prebiotic characteristics, and safety features were examined. All strains survived in MRS medium broth adjusted to pH 3.8, at $10^{\circ}C$ for 6 days, and did not produce $CO_2$ to check post fermentation. The medium of grapefruit extract fermentation by Lactobacillus plantarum CJIH 203 resulted in maximal viable counts, compared with other strains, and the extract subsequently tasted sour due to the presence of lactic acid. Lactobacillus plantarum CJIH203 was highly resistant to artificial gastric juice and intestinal juice, while Lactococcus lactis SJ09 strongly adhered to HT-29 cells. Tagatose showed the greatest ability to enhance the growth of L. plantarum SJ21, relative to the other strains. All strains were verified by safety tests such as hemolysis, gelatin hydration, and urea degradation. Therefore, these strains could be promising candidates for use in reducing excessive post-fermentation and functional products.

• Asian-Australasian Journal of Animal Sciences
• /
• v.15 no.12
• /
• pp.1790-1797
• /
• 2002

Lactic acid bacteria were isolated from piglets and chicken and characterized. Lactic acid bacteria showing resistance to low pH and bile, adhesion to intestinal epithelium cells, and the inhibition of Escherichia coli and Salmonella spp. were identified as Lactobacillus acidophilus. L. acidophilus PF01 survived for 2 h in MRS broth adjusted to pH 2. L. acidophilus CF07 was less resistant than L. acidophilus PF01 to pH 2, but survived at pH 2.5 for 2 h. Both of isolates were able to grow in MRS broth containing 0.3% (w/v) bile, with L. acidophilus CF07 being more tolerant to bile than L. acidophilus PF01. L. acidophilus PF01 and CF07 adhered specifically to the duodenal and jejunal epithelium cells of piglet, and the cecal and duodenal epithelium cells of chicken, respectively. Both of isolates did not adhere to the epithelium cells of the various animal intestines from which they were isolated. When L. acidophilus was cultured with E. coli and Salmonella spp. in MRS broth, MRS broth containing 2% skim milk powder or modified tryptic soy broth at $37^{\circ}C$, L. acidophilus PF01 and CF07 inhibited the growths of E. coli K88 and K99, and S. enteritidis and S. typhimurium, respectively. Both of isolates were found to possess the essential characteristics of probiotic lactic acid bacteria for piglet and chicken.

• Journal of Periodontal and Implant Science
• /
• v.29 no.4
• /
• pp.995-1005
• /
• 1999

Alveolar bone destruction is a character-istic of periodontal disease. Treponema denticola are found in significantly increased numbers in the sites affected with periodontal disease. In order to clarify the role of T. denticola in destruction of alveo-lar bone in periodontal disease, this study was undertaken to determine the effect of sonicated extract of T. denticola on osteo-clast differentiation in co-culture system of mouse bone marrow cells and calvaria cells. The ability of osteoclast formation was estimated by counting the number of tar-tartrate resistant acid phosphatase(TRAP) positive cells. Sonicated extract of this bacteria stimulated osteoclast formation in a dose dependent manner(p<0.05). Indomathacin, an inhibitor of prostaglandin synthesis, decreased osteoclast formation induced by sonicated extract of this bacte-bacteria(p<0.05). Extract-induced osteoclast formation was decreased, when sonicated extract of bacteria was heated(p<0.05). These findings suggest that T. denticola induces osteoclast differentiation, and protein component of this bacteria and $PGE_2$ may play an important role in this process.

• Journal of Aquaculture
• /
• v.14 no.2
• /
• pp.81-87
• /
• 2001

Antimicrobial activity of the essential oil extracted from plants Artemisia princeps var. orientalis, Thuja orientalis and Chamaecyparis obtusa were tested against selected pathogenic bacteria and fungi of fish. At the concentrations above 500ppm, ingibitory effect of the oil of A. princeps var. orientalis was at its peak against Aeromonas hydrophila ATCC 14715, A. hydrophila CF-2, A. salmonicida ATCC 14174 and A. salmonicida EL-1 but the bacteria Edwardsiella tarda KBF-1, Vibrio anguillarum ATCC19264, V. ordalii ATCC33509 and Streptococcus sp. were insensitive. Likewise, the oil extract of T. orientalis showed the highest inhibitory activity against V. ordalii ATCC33509, E. tarda ECK-1, and E. tarda KBF-1 at 300ppm; however the activity was highest at 500ppm or A. hydrophila ATCC14715, A. hydrophila CF-2, A. salomonicida ATCC14174, A. salmonicida EL-1 and Streptococcus sp. SF-1. With increasing dose of C. obtusa oil, the inhibitory activity became more and more effective against A. hydrophila CF-2, A. salomonicida ATCC14174, E. tarda ECK-1 and Streptococcus sp. SF-1, but A. hydrophila ATCC14174, A. salmonicida EL-1, E. tarda KBF-1, V. anguillarum ATCC19264, V. ardalii ATCC33509 and gram positive bacteria (Streptococcus sp.) were somewhat resistant. A. princeps var. orientalis, T. orientalis and C. obtusa were also tested against Saprolegnia sp. at the oil concentrations of 10, 100, 500, 1,000, 1,500 and 2,000ppm. The inhibitory effect of the oil on the inhibit the mycelial growth of Saprolegnia sp. at 10ppm and completely inhibited at over 500ppm.

• Journal of the East Asian Society of Dietary Life
• /
• v.15 no.4
• /
• pp.457-464
• /
• 2005

The optimal concentration of ethanol to separate a high quantity of propolis was $60\%$ but that for the best flavonoids extraction was $80\%$ We compared the yields of propolis from different countries. In this study we used $60\%$ ethanol concentration as a standard. The yield of propolis was proportional to the contents of flavonoids. Namely, Polish propolis which showed the highest yield with $56\%$ by the extraction with $60\%$ ethanol revealed also the highest flavonoids content with $3.49\%$ among all the samples tested The major constituents of propolis differed from country to country. It has been suggested that the different geographical origin influenced the efficacy and the constituents of propolis. Antibacterial activity of ethanol extracted propolis from different countries was tested against 6 microbial strains of type cultures including Gram-positive (Staphylococcus aureus, Streptococcus uberis, Streptococcus agalactiae) and Gram- negative bacteria (Klebsiella pneumoniae, Proteus vulgaris and E coli) in vitro. Propolis extract showed anti-microbial activity against all the tested bacterial strains. In addition, propolis was sensitive to E coli which was resistant to broad spectrum antibiotics like ampicillin. These results showed that propolis may substituted for commercial antibiotics. The efficiency of anti-microbial activity of the propolis was slightly higher in $80\%$ than $97\%$ ethanol extract.

• Journal of Microbiology and Biotechnology
• /
• v.31 no.9
• /
• pp.1200-1209
• /
• 2021

Sepsis is an acute inflammatory response that leads to life-threatening complications if not quickly and adequately treated. Cytolysin, hemolysin, and pneumolysin are toxins produced by gram-positive bacteria and are responsible for resistance to antimicrobial drugs, cause virulence and lead to sepsis. This work assessed the effects of aloe-emodin (AE) and photodynamic therapy (PDT) on sepsis-associated gram-positive bacterial toxins. Standard and antibiotic-resistant Enterococcus faecalis, Staphylococcus aureus, and Streptococcus pneumonia bacterial strains were cultured in the dark with varying AE concentrations and later irradiated with 72 J/cm^-2 light. Colony and biofilm formation was determined. CCK-8, Griess reagent reaction, and ELISA assays were done on bacteria-infected RAW264.7 cells to determine the cell viability, NO, and IL-1β and IL-6 pro-inflammatory cytokines responses, respectively. Hemolysis and western blot assays were done to determine the effect of treatment on hemolysis activity and sepsis-associated toxins expressions. AE-mediated PDT reduced bacterial survival in a dose-dependent manner with 32 ㎍/ml of AE almost eliminating their survival. Cell proliferation, NO, IL-1β, and IL-6 cytokines production were also significantly downregulated. Further, the hemolytic activities and expressions of cytolysin, hemolysin, and pneumolysin were significantly reduced following AE-mediated PDT. In conclusion, combined use of AE and light (435 ± 10 nm) inactivates MRSA, S. aureus (ATCC 29213), S. pneumoniae (ATCC 49619), MDR-S. pneumoniae, E. faecalis (ATCC 29212), and VRE (ATCC 51299) in an AE-dose dependent manner. AE and light are also effective in reducing biofilm formations, suppressing pro-inflammatory cytokines, hemolytic activities, and inhibiting the expressions of toxins that cause sepsis.