In vitro activity of allicin against Staphylococcus epidermidis and influence of subinhibitory concentrations on biofilm formation

Pérez-Giraldo, Ciro; Cruz-Villalón, Gregorio; Sánchez-Silos, R.M.; Martínez-Rubio, Roser; Blanco, M. T.; Gómez-García, A. C.

doi:10.1046/j.1365-2672.2003.02030.x

Cited by 69 publications

(42 citation statements)

References 10 publications

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“…18 A previous study showed that sub-MICs of allicin may play a role in the prevention of adherence of Staphylococcus epidermidis to microtiter plates. 19 S epidermidis biofilm formation is known to be associated with the production of the polysaccharide intercellular adhesin (PIA), poly-Nacetylglucosamine polysaccharide (PNAG), and recent evidence indicates that staphylococcal accessory regulator (SarA), a central regulatory element that controls the production of S aureus virulence factors, is essential for the synthesis of PIA/PNAG and ensuing biofilm development in this species. 20 These results suggest that the enzymes participating in bacterial biofilm formation are specific to bacteria, and that the increase of bacterial attachment by garlic extract through upregulation of GTF family genes expression is therefore very specific to S mutans.…”

Section: Discussionmentioning

confidence: 99%

Effect of garlic on bacterial biofilm formation on orthodontic wire

Lee

Park

Kim

et al. 2011

The Angle Orthodontist

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Objective: To examine the effect of garlic extract on the biofilm formation by Streptococcus mutans on orthodontic wire and on glucosyltransferase gene expression. Materials and Methods: Growth inhibition of oral bacteria was tested after 50 mL of garlic extract was placed on an agar plate. The minimum inhibitory concentration (MIC) of garlic extract on S mutans growth was first determined. After cultivating streptococci in biofilm medium (BM)-sucrose with garlic extract and orthodontic wire, adenosine triphosphate (ATP) measurement and viable cell counting was performed from the bacteria attached on the wire. Scanning electron microscopy (SEM) analysis of morphology was observed on bacterial cells attached to orthodontic wire. The effect of garlic extract on gene expression was evaluated using quantitative real-time polymerase chain reaction (PCR) of glucosyltransferase. Results: Though garlic extract had a clear antibacterial effect on all microorganisms, it also enhanced S mutans attachment on orthodontic wire. Low concentration of garlic extract also increased glucosyltransferase gene expression of S mutans. Conclusions: Despite its antibacterial function, garlic extract increases biofilm formation by S mutans to orthodontic wire, likely through upregulation of glucosyltransferase expression. Garlic extract may thus play an important role in increased bacterial attachment to orthodontic wires. (Angle Orthod. 2011;81:895-900.)

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Section: Discussionmentioning

confidence: 99%

Effect of garlic on bacterial biofilm formation on orthodontic wire

Lee

Park

Kim

et al. 2011

The Angle Orthodontist

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“…Previous reports suggested that the use of sub-MIC concentrations of antibiotics could increase biofilm formation (35). However, more recent studies demonstrated that sub-MIC concentrations of some antibiotics are effective for reducing the amount of biofilm formed (6,17,34,43), which may have some clinical interest. However, other changes that can occur in the physiology of biofilm cells might compromise the general use of this strategy to prevent biofilm formation.…”

Section: Discussionmentioning

confidence: 99%

Effects of Growth in the Presence of Subinhibitory Concentrations of Dicloxacillin on Staphylococcus epidermidis and Staphylococcus haemolyticus Biofilms

Cerca

Martins

Sillankorva

et al. 2005

Appl Environ Microbiol

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Low concentrations of antibiotics can inhibit microbial adherence to medical device surfaces. However, little is known about the changes that occur in the physiology of bacteria within biofilms formed in the presence of subinhibitory (sub-MIC) concentrations of antibiotics. In this study, the densities and matrix compositions of biofilms formed by two coagulase-negative Staphylococcus species in the absence and in the presence of sub-MIC concentrations of dicloxacillin were evaluated. Biofilms formed in the presence of sub-MIC concentrations of dicloxacillin contained less biomass, and there were notable changes in the composition of the biofilm matrix. Changes in the spatial structure were also verified by confocal scanning laser microscopy, indicating that biofilms grown in the presence of sub-MIC concentrations of dicloxicilln had a lower cell density. Physiological alterations in the bacteria within biofilms grown in the presence of subinhibitory concentrations of the antibiotic were also evaluated. The results showed that there were differences in bacterial surface characteristics when cultures were grown in the presence of sub-MIC concentrations of dicloxacillin, including decreased hydrophobicity and decreased expression of the exopolysaccharide poly-N-acetylglucosamine. The elemental composition of the cell surface was also analyzed, and whereas in Staphylococcus epidermidis there were decreases in the oxygen and nitrogen contents, in Staphylococcus haemolyticus there were increases in these two parameters. Additionally, increases in resistance to several antibiotics were observed for the cells within biofilms formed in the presence of dicloxacillin.

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“…Optically active sulfoxides, [5][6][7][8][9][10] in general, represent an important class of pharmaceuticals and drug intermediates. [11] They often play an important role as therapeutic agents, such as anti-ulcer (proton pump inhibitors), [12][13][14][15][16] antibacterial, anti-atherosclerotic, [17][18][19] anthelmintic, [20] Adv. Synth …”

Section: Introductionmentioning

confidence: 99%

Mechanism of the Asymmetric Sulfoxidation in the Esomeprazole Process: Effects of the Imidazole Backbone for the Enantioselection

2009

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Abstract:The asymmetric sulfoxidation reaction of imidazole-based prochiral sulfides was studied to explore the mechanistic details of the highly efficient esomeprazole process, which is one of the few industrial scale catalytic asymmetric procedures. The synthetic studies revealed that the smallest subunit governing the selectivity in the esomeprazole process is an imidazole ring. Thus, by using the esomeprazole procedure methyl imidazole sulfide could be oxidized as efficiently as its several functionalized derivatives, including pyrmetazol. However, alkylation of the imidazole nitrogen led to a major drop of the enantioselectivity. Our atmospheric pressure chemical ionization-mass spectrometry (APCI/MS) studies indicate that addition of small amounts of water to the reaction mixture facilitates the formation of mononuclear titanium species, which are the active catalytic intermediates of the selective oxidation reaction. One of the most important features of the esomeprazole procedure is that amine additives increase the enantioselectivity of the oxidation process. The NMR studies of the presumed reaction intermediates show that under catalytic conditions the amines are able to coordinate to titanium and dissociate the coordinated imidazole substrate. The density functional theory (DFT) modelling studies provided new insights in the mechanism of the asymmetric induction. It was found that the oxidation requires a lower activation energy if the imidazole sulfide precursor does not coordinate to titanium. Two possible reaction paths were explored for this out of sphere oxidation mechanism. The most important interaction governing the enantioselection is hydrogen bonding between the N À H of the imidazole ring and the chiral tartrate ligand on titanium. Furthermore, the oxidation reaction imposes an important structural constraint to the TS structure involving a linear arrangement of the peroxide oxygens and the sulfur atom. This constraint and the N coordination of imidazole leads to a very strained structure for the inner sphere mechanism of the oxidation, which leads to a much higher activation barrier than the corresponding out of sphere process, and therefore it is unlikely.

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In vitro activity of allicin against Staphylococcus epidermidis and influence of subinhibitory concentrations on biofilm formation

Cited by 69 publications

References 10 publications

Effect of garlic on bacterial biofilm formation on orthodontic wire

Effect of garlic on bacterial biofilm formation on orthodontic wire

Effects of Growth in the Presence of Subinhibitory Concentrations of Dicloxacillin on Staphylococcus epidermidis and Staphylococcus haemolyticus Biofilms

Mechanism of the Asymmetric Sulfoxidation in the Esomeprazole Process: Effects of the Imidazole Backbone for the Enantioselection

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