Will triclosan in toothpaste select for resistant oral streptococci?

Supra and subgingival application of antiseptics or antibiotics during periodontal therapy

Periodontal diseases (gingivitis and periodontitis) are characterized by inflammatory processes which arise as a result of disruption of the balance in the oral ecosystem. According to the current S3 level clinical practice guidelines, therapy of patients with periodontitis involves a stepwise approach that includes the control of the patient's risk factors and the debridement of supra and subgingival biofilm. This debridement can be performed with or without the use of some adjuvant therapies, including physical or chemical agents, host modulating agents, subgingivally locally delivered antimicrobials, or systemic antimicrobials. Therefore, the main aim of this article is to review in a narrative manner the existing literature regarding the adjuvant application of local agents, either subgingivally delivered antibiotics and antiseptics or supragingivally applied rinses and dentifrices, during the different steps in periodontal therapy performed in Europe.

Comparison of Antimicrobial Efficacy of Triclosan- Containing, Herbal and Homeopathy Toothpastes- An Invitro Study

BACKGROUND

Use of antimicrobial agents is one of the important strategies to prevent oral diseases. These agents vary in their abilities to deliver preventive and therapeutic benefits.

OBJECTIVES

This invitro study was conducted to assess antimicrobial efficacy of different toothpastes against various oral pathogens.

MATERIALS AND METHODS

A total of nine toothpastes in three groups were tested for their antimicrobial activity against Escherichia coli (ATCC 25922), Staphylococcus aureus (ATCC 25923), Streptococcus mutans (ATCC 0266P) and Candida albicans (Laboratory Strain) by modified agar well diffusion method. Statistical Analysis was performed using Minitab Software. A p-value of less than 0.05 was considered significant.

RESULTS

Triclosan-based dental formulation with combination of fluoride (1000ppm) exhibited higher antimicrobial activity against test organisms than the combination of lower fluoride-concentration or sodium monofluorophosphate. Among herbal dentifrices, formulation containing Neem, Pudina, Long, Babool, Turmeric and Vajradanti showed significant antimicrobial activity against all the four tested microorganisms (p<0.05). However, against Streptococcus mutans, all three herbal products showed significant antimicrobial activity. Homeo products showed least antimicrobial activity on the tested strains. Formulation with kreosotum, Plantago major and calendula was significantly effective only against Streptococcus mutans.

CONCLUSION

In the present study, antimicrobial activity of the toothpaste containing both triclosan and fluoride (1000ppm) as active ingredients showed a significant difference (p< 0.05) against all four tested microflora compared to that of with lower fluoride-concentration or sodium monofluorophosphate. Of herbal groups, the only dentifrice containing several phytochemicals was found to be significantly effective and comparable to triclosan-fluoride (1000ppm) formulation. Thus, this herbal toothpaste can be used as alternative to triclosan-based formulations. However, these results might not be clinically useful unless tested invivo.

Community-level assessment of dental plaque bacteria susceptibility to triclosan over 19 years

Background

Triclosan is a broad-spectrum antimicrobial agent used in toothpaste to reduce dental plaque, gingivitis and oral malodor. This community-level assessment evaluated the susceptibility of dental plaque bacteria to triclosan in samples collected over 19 years.

Methods

A total of 155 dental plaque samples were collected at eleven different times over 19 years from 58 adults using 0.3% triclosan, 2% copolymer, 0.243% sodium fluoride toothpaste and from 97 adults using toothpaste without triclosan. These included samples from 21 subjects who used triclosan toothpaste for at least five years and samples from 20 control subjects. The samples were cultured on media containing 0, 7.5 or 25 μg/ml triclosan. Descriptive statistics and p values were computed and a linear regression model and the runs test were used to examine susceptibility over time.

Results

Growth inhibition averaged 99.451% (91.209 - 99.830%) on media containing 7.5 μg/ml triclosan and 99.989% (99.670 - 100%) on media containing 25 μg/ml triclosan. There was no change in microbial susceptibility to triclosan over time discernible by regression analysis or the runs test in plaque samples taken over 19 years including samples from subjects using a triclosan-containing dentifrice for at least five years.

Conclusions

This community-level assessment of microbial susceptibility to triclosan among supragingival plaque bacteria is consistent with the long-term safety of a 0.3% triclosan, 2% copolymer, 0.243% sodium fluoride dentifrice.

An in vitro study of alginate oligomer therapies on oral biofilms

OBJECTIVES

The in vitro effect of a novel, oligosaccharide nanomedicine OligoG against oral pathogen-related biofilms, both alone and in the presence of the conventional anti-bacterial agent triclosan, was evaluated.

METHODS

The effect of OligoG±triclosan was assessed against established Streptococcus mutans and Porphyromonas gingivalis biofilms by bacterial counts and image analysis using LIVE/DEAD(®) staining and atomic force microscopy (AFM). The effect of triclosan and OligoG surface pre-treatments on bacterial attachment to titanium and polymethylmethacrylate was also studied.

RESULTS

OligoG potentiated the antimicrobial effect of triclosan, particularly when used in combination at 0.3% against S. mutans grown in artificial saliva. OligoG was less effective against established P. gingivalis biofilms. However, attachment of P. gingivalis, to titanium in particular, was significantly reduced after surface pre-treatment with OligoG and triclosan at 0.01% when compared to controls. Light microscopy and AFM showed that OligoG was biocidal to P. gingivalis, but not S. mutans.

CONCLUSIONS

OligoG and triclosan when used in combination produced an enhanced antimicrobial effect against two important oral pathogens and reduced bacterial attachment to dental materials such as titanium, even at reduced triclosan concentrations. Whilst the use of triclosan against oral bacteria has been widely documented, its synergistic use with OligoG described here, has not previously been reported. The use of lower concentrations of triclosan, if used in combination therapy with OligoG, could have environmental benefits.

CLINICAL IMPORTANCE

The potentiation of antimicrobial agents by naturally occurring oligomers such as OligoG may represent a novel, safe adjunct to conventional oral hygiene and periodontal therapy. The ability of OligoG to inhibit the growth and impair bacterial adherence highlights its potential in the management of peri-implantitis.

Staphylococcus epidermidis isolated in 1965 are more susceptible to triclosan than current isolates

Since its introduction to the market in the 1970s, the synthetic biocide triclosan has had widespread use in household and medical products. Although decreased triclosan susceptibility has been observed for several bacterial species, when exposed under laboratory settings, no in vivo studies have associated triclosan use with decreased triclosan susceptibility or cross-resistance to antibiotics. One major challenge of such studies is the lack of strains that with certainty have not been exposed to triclosan. Here we have overcome this challenge by comparing current isolates of the human opportunistic pathogen Staphylococcus epidermidis with isolates collected in the 1960s prior to introduction of triclosan to the market. Of 64 current S. epidermidis isolates 12.5% were found to have tolerance towards triclosan defined as MIC≥0.25 mg/l compared to none of 34 isolates obtained in the 1960s. When passaged in the laboratory in the presence of triclosan, old and current susceptible isolates could be adapted to the same triclosan MIC level as found in current tolerant isolates. DNA sequence analysis revealed that laboratory-adapted strains carried mutations in fabI encoding the enoyl-acyl carrier protein reductase isoform, FabI, that is the target of triclosan, and the expression of fabI was also increased. However, the majority of the tolerant current isolates carried no mutations in fabI or the putative promoter region. Thus, this study indicates that the widespread use of triclosan has resulted in the occurrence of S. epidermidis with tolerance towards triclosan and that the adaptation involves FabI as well as other factors. We suggest increased caution in the general application of triclosan as triclosan has not shown efficacy in reducing infections and is toxic to aquatic organisms.

4-Nonylphenol, bisphenol-A and triclosan levels in human urine of children and students in China, and the effects of drinking these bottled materials on the levels

4-Nonylphenol (4-NP), bisphenol-A (BPA) and triclosan (TCS) are three industrial chemicals used widely in daily products. This study investigated 4-NP, BPA and TCS levels in urine samples of 287 children and students aged from 3 to 24 years old in Guangzhou, China. Total (free and conjugated) amounts of 4-NP, BPA and TCS in the urine samples were detected using gas chromatography-mass spectrometry with negative chemical ionization. The detection rates of 4-NP, BPA and TCS were 100%, 100% and 93% respectively, given the detection limits of 3.8, 0.5 and 0.9 ng/L respectively. Data for 4-NP, BPA and TCS were presented in both creatinine-adjusted (microgram per gram creatinine) and unadjusted (microgram per liter) urinary concentrations. The geometric mean (GM) concentrations of urinary 4-NP, BPA and TCS were 15.92 μg/g creatinine (17.40 μg/L), 2.75 μg/g creatinine (3.00 μg/L) and 3.55 μg/g creatinine (3.77 μg/L) respectively. Multiple regression models considering age, gender, preferred drinking bottle and log-transformed creatinine were used to calculate the adjusted least square geometric mean (LSGM). Among these subjects, the females had higher LSGM concentrations of 4-NP, BPA and TCS than the males; and the only statistically significant difference was found for the LSGM concentrations of triclosan (p=0.031). Participants who reported to use ceramic cups more frequently had significantly lower LSGM concentrations of BPA than those who used plastic cups (p=0.037). Meanwhile, a three-week test of using polycarbonate bottles and ceramic cups to drink bottled water and boiled tap-water was carried out among 12 graduate students of 25 years old. The GM concentrations of urinary BPA at the end of the first week after using ceramic cups to drink bottled water were 7.16 μg/g creatinine, then decreased significantly to 3.49 μg/g creatinine after the second week of using ceramic cups to drink boiled tap-water (p<0.05), and finally increased to 4.15 μg/g creatinine after the third week of using polycarbonate bottles in drinking boiled tap-water. The results indicate that in daily life the use of polycarbonate bottles or drinking of bottled water is likely to increase the ingestion of BPA, resulting in an increase in urinary BPA levels.

Triclosan inhibition of acute and chronic inflammatory gene pathways

AIM

We sought to determine whether triclosan (2,4,4'-trichloro-2'-hydroxydiphenylether), an extensively used anti-plaque agent with broad-spectrum anti-microbial activity, with reported anti-inflammatory effects via inhibition of prostaglandin E2 and interleukin 1 (IL-1)beta, could also more broadly suppress multiple inflammatory gene pathways responsible for the pathogenesis of gingivitis and periodontitis.

MATERIALS AND METHODS

As an exploratory study, the effects of triclosan on the inflammatory gene expression profile were assessed ex vivo using peripheral whole blood samples from eight periodontally healthy donors. Ten-millilitres whole blood aliquots were incubated 2 h with 0.3 microg/ml Escherichia coli lipopolysaccharide (LPS) with or without 0.5 microg/ml triclosan. Affymetrix microarray gene expression profiles from isolated leucocytes and pathway-specific quantitative polymerase chain reaction arrays were used to investigate changes in expression of target cytokines and cell signalling molecules.

RESULTS

Ex vivo human whole blood assays indicated that triclosan significantly down-regulated the LPS-stimulated expression of Toll-like receptor signalling molecules and other multiple inflammatory molecules including IL-1 and IL-6 and the dampening of signals that activate the T-helper type 1 acquired immune response via suppression of CD70 with concomitant up-regulation of growth factors related to bone morphogenetic protein (BMP)2 and BMP6 synthesis.

CONCLUSIONS

Anti-inflammatory effects were found in this exploratory survey, including suppression of microbial-pathogen recognition pathway molecules and the suppression of acute and chronic mediators of inflammation.

Pharmacokinetics of triclosan following oral ingestion in humans

The number of personal hygiene products containing triclosan has increased rapidly during the last decade, and triclosan is one of the most common antibacterial compounds used in dentifrices today. However, the extent of triclosan exposure has not yet been well described. The potential risks of generating triclosan-resistant pathogenic microorganisms or of the selection of resistant strains are some areas of concern. The aim of the present study was to (1) obtain information on baseline levels of triclosan in plasma and urine, and (2) study the pharmacokinetic pattern of triclosan after a single-dose intake. Ten healthy volunteers were exposed to a single oral dose of 4 mg triclosan by swallowing an oral mouthwash solution. Triclosan in plasma and urine was followed before and up to 8 d after exposure. Triclosan levels in plasma increased rapidly, with a maximum concentration within 1 to 3 h, and the terminal plasma half-life was 21 h. The major fraction was excreted within the first 24 h. The accumulated urinary excretion varied between the subjects, with 24 to 83% of the oral dose being excreted during the first 4 d after exposure. In conclusion, triclosan appears to be readily absorbed from the gastrointestinal tract and has a rapid turnover in humans. The high lipid solubility of the substance gives rise to questions regarding distribution properties and accumulation. The findings of the present study form a basis for greater understanding of the toxicokinetic properties of triclosan in humans.

Triclosan and Antimicrobial Resistance in Bacteria: An Overview

Triclosan is a widely used biocide that is considered as an effective antimicrobial agent against different microorganisms. It is included in many contemporary consumer and personal health-care products, like oral and dermal products, but also in household items, including plastics and textiles. At bactericidal concentrations, triclosan appears to act upon multiple nonspecific targets, causing disruption of bacterial cell wall functions, while at sublethal concentrations, triclosan affects specific targets. During the 1990s, bacterial isolates with reduced susceptibility to triclosan were produced in laboratory experiments by repeated exposure to sublethal concentrations of the agent. Since 2000, a number of studies have verified the occurrence of triclosan resistance amongst dermal, intestinal, and environmental microorganisms, including some of clinical relevance. Of major concern is the possibility that triclosan resistance may contribute to reduced susceptibility to clinically important antimicrobials, due to either cross-resistance or co-resistance mechanisms. Although the number of studies elucidating the association between triclosan resistance and resistance to other antimicrobials in clinical isolates has been limited, recent laboratory studies have confirmed the potential for such a link in Escherichia coli and Salmonella enterica. Thus, widespread use of triclosan may represent a potential public health risk in regard to development of concomitant resistance to clinically important antimicrobials.

Antibacterial cleaning and hygiene products as an emerging risk factor for antibiotic resistance in the community

Antibiotic resistance within the community setting is an emerging public-health concern. Infection with antibiotic-resistant organisms in the community among people lacking traditional risk factors has been reported. In addition, prevalence studies have identified individuals carrying antibiotic-resistant organisms in the absence of known risk factors. These studies strongly suggest the presence of contributing factors that have yet to be identified. In this paper we review the burden of antibiotic resistance and known risk factors within the community setting, assess the potential role of antibacterial cleaning and hygiene products containing triclosan in the emergence of resistance, and recommend future research on the assessment of household cleaning and hygiene products containing triclosan.

Bacterial outer membrane and cell wall penetration and cell destruction by polluting chemical agents and physical conditions

In the environment, bacteria and other microorganisms are subjected to a variety of constantly changing chemical and physical agencies. Chemical ones include antimicrobial compounds (both biocides and antibiotics), pollutants, drugs, cosmetic and pharmaceutical ingredients and pesticides. The physical agents include desiccation and drying, osmotic pressure, hydrostatic pressure, temperature and pH changes and radiations (ultraviolet, sunlight, ionizing). Bacteria must thus adapt to survive these inimicable conditions. Organisms such as bacterial spores usually survive, whereas other types of microorganisms may be much more susceptible. Depending on the type of organism, the bacterial cell wall, outer membrane or the spore outer layers may act as permeability barriers to the intracellular uptake of antibiotics and biocides. Some antibacterial agents interact with, and damage or modify, the outer components. Physical agencies are known to damage the cytoplasmic membrane or to produce alterations in DNA or proteins or enzymes. Nevertheless, significant damage to the cell wall or outer membrane may also occur. Four types of organisms are considered: cocci, mycobactria, Gram-negative bacteria and bacterial spores. The nature of the damage inflicted on, or in some cases prevented by, their outer cell layers is discussed for each type of organism.