scholarly journals Antimicrbial Effect of Diode Laser and Biossynthesis Silver Nanoparticles on Bactrium Staphylococcus Aureus in Vitro

2018 ◽  
Vol 7 (4.36) ◽  
pp. 290
Author(s):  
Raad Sh. Alnayli ◽  
Adnan H. Al Hamadani ◽  
Safaa A. Yaseen

The present work was aimed to illustrate how the use of Diode laser or silver nanoparticles (AgNPs) each of them individually, as an antibacterial agent against  Staphylococcus aureus (S. aureus) as well as study the effective result from the absorption of laser energy by these nanoparticles to kill or inhibition bacterial growth. The silver nanoparticles are prepared by biological method. S. aureus are isolated and identified in the Central Health Laboratory in Al Najaf city. Nanoparticles are tested against S. aureus cultured on Muller Hinton agar but Diode laser or laser with nanoparticles are tested against S. aureus cultured in Nutrient broth. S. aureus are irradiating by Diode laser with different irradiation times, moreover there are different concentrations of AgNPs have been employed for killing and inhibition bacterial growth. Results showed that S. aureus is affected by AgNPs (mainly highest concentration of nanoparticles) also detected that decrease bacterial availability with increase time of irradiation to laser. 

2020 ◽  
Vol 8 (10) ◽  
pp. 1478 ◽  
Author(s):  
Dobroslava Bujňáková ◽  
Anna Čuvalová ◽  
Milan Čížek ◽  
Filip Humenik ◽  
Michel Salzet ◽  
...  

The present study investigated the in vitro antibacterial, antibiofilm and anti-Quorum Sensing (anti-QS) activities of canine bone marrow mesenchymal stem cell-conditioned media (cBM MSC CM) containing all secreted factors <30 K, using a disc diffusion test (DDT), spectrophotometric Crystal Violet Assay (SCVA) and Bioluminescence Assay (BA) with QS-reporter Escherichia coli JM109 pSB1142. The results show a sample-specific bacterial growth inhibition (zones varied between 7–30 mm), statistically significant modulation of biofilm-associated Staphylococcus aureus and Escherichia coli bioluminescence (0.391 ± 0.062 in the positive control to the lowest 0.150 ± 0.096 in the experimental group, cf. 11,714 ± 1362 to 7753 ± 700, given as average values of absorbance A550 ± SD versus average values of relative light units to growth RLU/A550 ± SD). The proteomic analysis performed in our previous experiment revealed the presence of several substances with documented antibacterial, antibiofilm and immunomodulatory properties (namely, apolipoprotein B and D; amyloid-β peptide; cathepsin B; protein S100-A4, galectin 3, CLEC3A, granulin, transferrin). This study highlights that cBM MSC CM may represent an important new approach to managing biofilm-associated and QS signal molecule-dependent bacterial infections. To the best of our knowledge, there is no previous documentation of canine BM MSC CM associated with in vitro antibiofilm and anti-QS activity.


2018 ◽  
Vol 28 (5) ◽  
pp. 52-57
Author(s):  
Jeanette Guadalupe Cárdenas-Valdovinos ◽  
Guadalupe Oyoque-Salcedo ◽  
Pedro Damian Loeza-Lara ◽  
Ernesto Oregel-Zamudio ◽  
Maria Valentina Angoa-Perez ◽  
...  

In this study, the effect of anthocyanic extracts of strawberry (Fragaria x ananassa Duch.) variety Jacona on the in vitro growth of Staphylococcus aureus associated to bovine mastitis was evaluated. Sensitivity tests were carried out on the anthocyanic extracts by disk difussion method (10 µg/disk-100 µg/disk), using the antibiotic Dicloxacillin® as positive control (50 µg/mL, 50 µL/disk) and percentages of inhibition of bacterial growth were determined. Anthocyanic extracts managed to inhibit the bacterial growth of the strain ATCC 27543 and the isolated STA28 of S. aureus up to 54% and 40%, respectively. The results showed the antimicrobial potential of anthocyanic extracts of strawberry against S. aureus associated to bovine mastitis.


2020 ◽  
Vol 33 (04) ◽  
pp. 243-251
Author(s):  
Bahar Gerivani ◽  
Hamid Staji ◽  
Maryam Rassouli ◽  
Nooshin Ghazaleh ◽  
Abbas Javaheri Vayeghan

Abstract Objective Erythromycin (Ery) and leech saliva (LS) can inhibit Staphylococcus aureus growth in in vitro conditions. This study aimed to evaluate the activities and synergy between Ery and LS on chronic osteomyelitis in male Wistar rat's tibia induced by methicillin-resistant S. aureus (MRSA). Materials and Methods Four weeks after osteomyelitis induction, rats were divided into four groups including no treatment (control), Ery monotherapy (orally), LS monotherapy, or Ery + LS twice daily for 2 weeks. Staphylococcus aureus growth, pathological signs and inflammatory cytokine tumour necrosis factor-alpha (TNF-α) levels were assessed. Results Rats tolerated all therapeutic strategies well during the experiment. The Ery treatment alone significantly decreased bacterial growth, pathological signs and TNF-α levels. Leech saliva alone reduced TNF-α level significantly, but did not produce a significant reduction in bacterial growth and pathological signs. Ery + LS treatment significantly decreased bacterial growth, considerably alleviated bone pathological signs and decreased TNF-α levels compared with other groups. Statistical analysis suggested that there was a stronger efficiency and synergistic action of Ery and LS when combined against MRSA-induced osteomyelitis in rats. Clinical Significance The present study suggests that LS may have clinical utility to treat MRSA-induced osteomyelitis when combined with Ery or other therapeutics.


Author(s):  
Sri Atun ◽  
Sri Handayani ◽  
Melia Aliffiana ◽  
Hajar Nur Afifah ◽  
Anna Rakhmawati

The antibacterial activity of three Cupressaceae plants (Thujaoccidentalis,ThujaorientalisandChamaecyparisobtusa) was tested against three bacteria using the agar diffusion method. The ether and ethylacetate fraction of crude methanol extract from the three plants showed potent antibacterial activity against the tested microorganisms. The result showed that Staphylococcus aureus revealed the most sensitivity among the tested bacteria. Thujaoccidentalisether fraction and Thujaorientalis hexane fraction exhibited the highest antibacterial activity against Staphylococcus aureus. E. coli was shown the highest MIC values compared to the other two tested bacteria, which indicates the lowest antibacterial activity against the bacterium. This study promises an interesting future for designing a potentially active antibacterial agent from the three Cupressaceae plants.


2018 ◽  
Vol 930 ◽  
pp. 212-217
Author(s):  
Marcos Antônio Guerra ◽  
Jeferson Prado Swerts ◽  
Mei Abe Funcia ◽  
Maria Gabriela Nogueira Campos

This study evaluated the antimicrobial activity of PET-Silver nanocomposite filaments at different concentrations (0, 0.180%, 0.135%, 0.090%, 0.045% and 0.022% w/w) of silver nanoparticles in order to determine the minimum inhibitory concentration and minimum bactericidal concentration of silver incorporated in the PET matrix. The in vitro antibacterial activity was evaluated by the AATCC standard 100: 2012 method, against Staphylococcus aureus ATCC 6538, and Klebsiella pneumonia ATCC 4532. The filaments were tested after one and twenty-one months of preparation to evaluate the effect of time on the antimicrobial activity of the nanocomposites. Moreover, the antimicrobial activity was also evaluated after dyeing the filaments. The silver-free PET filaments have not demonstrated antimicrobial activity and cytotoxicity against human dermal fibroblasts. Nevertheless, excepted for the filament with 0.022% of silver nanoparticles, all PET-Silver nanocomposites reduced more than 99% the colony-forming units (CFU) of Staphylococcus aureus and Klebsiella pneumonia after one and twenty-one months of preparation. This suggests that the MIC of silver nanoparticles incorporated in the PET matrix is lower than 220 ppm (w/w) and the MBC is between 0.022 and 0.045% (w/w). However, after the dyeing process, no antimicrobial activity was observed for any PET-Silver nanocomposite filaments. This may be attributed to the release of silver from the PET matrix during the dyeing process or to the reaction/inactivation of the silver ions by the salts used in this chemical treatment.


1972 ◽  
Vol 55 (1) ◽  
pp. 219-223
Author(s):  
John H S Chen ◽  
L F Ortenzio

Abstract A simple turbidimetric method has been developed for determining the degree of phenol resistance of cultures used for disinfectant testing. Net transmission values are used to assess t h e degree of resistance; these are based on t h e measurement of the total amount of light scattered by the bacterial growth i n the AOAC broth medium without interfering turbidity of the dissolved ingredients. A decrease in the net transmission value corresponds to a decrease in phenol resistance; the converse is also true . The transmission values obtained in a 10 month study of a total of 77 weekly r and om samples of AOAC nutrient broth media blanks showed no substantial differences among the broth media tested by the turbidimetric method. Net transmission values were obtained for 71 broth cultures of Salmonella choleraesuis, 74 of Staphylococcus aureus, and 78 of Pseudomonas aeruginosa having the same required resistance against phenol. These values, which fell within a wider range than would be expected, are given. The effect of the number of 10-carrier-soakings on the net transmission value and equivalent phenol resistance of the cultures was determined for 60 broth cultures of the 3 test organisms named above. Soaking wet cylinder carriers in a given volume of test cultures used for the AOAC use-dilution test directly reduced the net transmission value and equivalently decreased the phenol resistance of the cultures. The turbidimetric method has proven experimentally satisfactory i n several hundred determinations and in selecting test cultures of uniform quality for disinfectant testing.


2005 ◽  
Vol 187 (22) ◽  
pp. 7876-7880 ◽  
Author(s):  
Junsong Sun ◽  
Li Zheng ◽  
Christina Landwehr ◽  
Junshu Yang ◽  
Yinduo Ji

ABSTRACT Two-component signal transduction systems play an important role in the ability of bacteria to adapt to various environments by sensing changes in their habitat and by altering gene expression. In this study, we report a novel two-component system, YhcSR, in Staphylococcus aureus which is required for bacterial growth in vitro. We found that the down-regulation of yhcSR expression by induced yhcS antisense RNA can inhibit and terminate bacterial growth. Moreover, without complementary yhcS or yhcR, no viable yhcS or yhcR gene replacement mutant was recoverable. Collectively, these results demonstrated that the YhcSR regulatory system is indispensable for S. aureus growth in culture. Moreover, induced yhcS antisense RNA selectively increased bacterial susceptibility to phosphomycin. These data suggest that YhcSR probably modulates the expression of genes critical for bacterial survival and may be a potential target for the development of novel antibacterial agents.


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