Antibiotic resistance

Antimicrobial photodynamic therapy in treatment of aggressive periodontitis (stage III, grade C periodontitis): A comparison between photodynamic therapy and antibiotic therapy as an adjunct to non-surgical periodontal treatment

BACKGROUND

Treatment of aggressive periodontitis (stage III, grade C periodontitis) represents a challenge. The aim of the study was to compare the long-term results of antimicrobial photodynamic therapy (aPDT) and antibiotic therapy as an adjunct to conventional non-surgical therapy in patients with aggressive periodontitis.

MATERIALS AND METHODS

Twenty subjects with untreated aggressive periodontitis (stage III, grade C periodontitis) were divided into two groups: the test group (TG) received non-surgical therapy and two sessions of aPDT using a laser (HELBO TheraLite laser) with a wavelength of 670 nm associated with HELBO Blue photosensitizer, and the control group (CG) received non-surgical therapy and antibiotics (amoxicillin 500 mg and metronidazole 400 mg, 7 days). Clinical parameters of probing depth, clinical attachment level and bleeding on probing (BOP) were assessed at baseline, 3, 6, 9 and 12 months after treatment.

RESULTS

The mean probing pocket depths at baseline were 3.68 mm in TG and 3.51 mm in CG. These values decreased to 2.77 mm (p < 0.05) and 2.54 mm (p < 0.05) 3 months after treatment and stayed decreased after 12 months. Clinical attachment levels at baseline were 3.88 mm in TG and 3.70 mm in CG. These values decreased to 3.06 mm (p < 0.05) and 2.80 mm (p < 0.05) after 3 months and stayed decreased after 12 months. We also found a decrease in BOP after 3, 6, 9 and 12 months in TG and in CG.

CONCLUSIONS

aPDT and antibiotics as an adjunct to non-surgical periodontal treatment lead to a comparable improvement in long term periodontal parameters.

Effect of Locally Delivered Minocycline on the Profile of Subgingival Bacterial Genera in Patients with Periodontitis: A Prospective Pilot Study

This prospective pilot study aimed to evaluate the effect of minocycline-HCl ointment (MO), locally delivered as an adjunct to scaling and root planing (SRP), on subgingival microflora. A total of 59 periodontitis patients received SRP as an initial periodontal therapy. In the selected periodontal pockets with probing depths (PD) of 6−9 mm, the sites that exhibited a positive reaction following a bacterial test using an immunochromatographic device were subsequently treated with MO (SRP + MO group, n = 25). No additional treatment was performed at sites showing a negative reaction (SRP group, n = 34). In addition to subgingival plaque sampling, measurement of clinical parameters including PD, clinical attachment level (CAL), bleeding on probing (BOP), plaque index and gingival index (GI) were performed at baseline and 4 weeks after the initial periodontal therapy. The subgingival microflora were assessed by terminal restriction fragment-length polymorphism analysis. Relative to baseline values, the mean scores for PD-, CAL-, BOP-, and GI-sampled sites were significantly decreased post treatment in both groups (p < 0.01). The intra-comparisons showed a significant decrease in the counts of the genera Eubacterium, Parvimonas, Filifactor, Veillonella, Fusobacterium, Porphyromonas, Prevotella, and unknown species in the SRP + MO group (p < 0.05). Inter-comparisons indicated a significant decrease in the genera Veillonella in the SRP + MO group (p = 0.01). Combination therapy of SRP and local MO induced a change in the subgingival microbial community: particularly, the number of Veillonella spp. was markedly reduced.

Protective Effects of Natural Polysaccharides on Intestinal Barrier Injury: A Review

Owing to their minimal side effects and effective protection from oxidative stress, inflammation, and malignant growth, natural polysaccharides (NPs) are a potential adjuvant therapy for several diseases caused by intestinal barrier injury (IBI). More studies are accumulating on the protective effects of NPs with respect to IBI, but the underlying mechanisms remain unclear. Thus, this review aims to represent current studies that investigate the protective effects of NPs on IBI by directly maintaining intestinal epithelial barrier integrity (inhibiting oxidative stress, regulating inflammatory cytokine expression, and increasing tight junction protein expression) and indirectly regulating intestinal immunity and microbiota. Furthermore, the mechanisms underlying IBI development are briefly introduced, and the structure-activity relationships of polysaccharides with intestinal barrier protection effects are discussed. Potential developments and challenges associated with NPs exhibiting protective effects against IBI have also been highlighted to guide the application of NPs in the treatment of intestinal diseases caused by IBI.

Evaluation of Antibiotic Prescribing Patterns in Paediatric Dental Patients: Cross - Sectional Epidemiological Study

Background/Aim: The purpose of this study was to investigate the antibiotic prescribing patterns for the treatment of paediatric oral infection, dental trauma and prophylaxis among dentists in Turkey.

Material and Methods: A total of 206 paediatric dentists, including general dentists, paediatric dentists and specialist dentists, participated in this cross-sectional study. The questionnaire included questions about the number of paediatric patients treated and antibiotics prescribed, the most commonly prescribed antibiotic for oral infections and the clinical conditions under which antibiotics were prescribed. The participants’ ages, workplaces and professional experience were also evaluated.

Results: The majority of the participants were paediatric dentists (45.1%) and general dentists (42.7%). For the management of dental infections, most dentists prescribed penicillin (94.7%). Their foremost prescription choices for the presence of an anaerobic infection were metronidazole (48.5%) and penicillin (32%). For dental trauma, the most common antibiotic-prescribed cases were avulsion and contaminated wounds, followed by alveolar fracture. Antibiotics were prescribed as a first choice for dental infections and dental infections of anaerobic origin, with no significant differences between professional experience or dental specialty in the dentists (p > 0.05). Practitioners belonging to Ministry of Health dental centres significantly differed from all other groups in preferring the antibiotic cephalosporin for dental infections of anaerobic origin.

Conclusions: Adherence to published guidelines for antibiotic prescriptions for anaerobic dental infections and dental trauma was low. Clearer, more specific guidelines and increased post-graduate education could lead to a reduction in the negative consequences of this issue’s resultant over-prescribed antibiotics.

Effectiveness of Antimicrobial Photodynamic Therapy in the Treatment of Periodontitis: A Systematic Review and Meta-Analysis of In Vivo Human Randomized Controlled Clinical Trials

This systematic review and meta-analysis evaluated antimicrobial photodynamic therapy (aPDT) efficacy in periodontitis. The review protocol was conducted in accordance with PRISMA statements, Cochrane Collaboration recommendations and is registered in PROSPERO (CRD 42020161516). Electronic and hand search strategies were undertaken to gather data on in vivo human RCTs followed by qualitative analysis. Differences in probing pocket depth (PPD) and clinical attachment level (CAL) were calculated with 95% confidence intervals and pooled in random effects model at three and six months. Heterogeneity was analyzed, using Q and I² tests. Publication bias was assessed by visual examination of the funnel plot symmetry. Sixty percent of 31 eligible studies showed a high risk of bias. Meta-analysis on 18 studies showed no additional benefit in split mouth studies in terms of PPD reduction (SMD 0.166; 95% CI −0.278 to 0.611; P = 0.463) and CAL gain (SMD 0.092; 95% CI −0.013 to 0.198; P = 0.088). Similar findings noted for parallel group studies; PPD reduction (SMD 0.076; 95% CI −0.420 to 0.573; P = 0.763) and CAL gain (SMD 0.056; 95% CI −0.408 to 0.552; P = 0.745). Sensitivity analysis minimized heterogeneity for both outcome variables; however, intergroup differences were not statistically significant. Future research should aim for well-designed RCTs in order to determine the effectiveness of aPDT.

Heat-killed Lactobacillus acidophilus mediates Fusobacterium nucleatum induced pro-inflammatory responses in epithelial cells

Probiotics is widespreadly used nowadays. However, the safety issue with the use of live probiotics is still a matter of contention. In recent years, an expanding body of evidence supports the beneficial role of heat-killed probiotics in the maintenance of systemic health, whereas the role of these heat-killed bacteria on periodontal health remains unclear. This study aimed to evaluate the effects of heat-killed probiotics on periodontal pathogen virulence and associated mechanisms. We demonstrated that heat-killed Lactobacillus acidophilus was able to coaggregate with Fusobacterium nucleatum, the bridging bacteria of oral biofilm, and inhibit the adhesion and invasion of F. nucleatum, leading to a subsequent elimination of pro-inflammatory cytokine production in oral epithelial cells. This coaggregation further caused a suppression of the virulence gene fap2 expression in F. nucleatum. Therefore, heat-killed L. acidophilus might downregulate the pro-inflammatory cytokine expression in epithelial cells via coaggregation with F. nucleatum and suppression of F. nucleatum fap2 expression, which was the first demonstration that heat-killed probiotics modulate periodontal disease pathogenesis via coaggregation. Collectively, this finding provides new evidence that heat-killed probiotics might exert beneficial effects to periodontal health by coaggregating with periodontal pathogens and modulating their virulence.

Strategic Moves of "Superbugs" Against Available Chemical Scaffolds: Signaling, Regulation, and Challenges

Superbugs' resistivity against available natural products has become an alarming global threat, causing a rapid deterioration in public health and claiming tens of thousands of lives yearly. Although the rapid discovery of small molecules from plant and microbial origin with enhanced bioactivity has provided us with some hope, a rapid hike in the resistivity of superbugs has proven to be the biggest therapeutic hurdle of all times. Moreover, several distinct mechanisms endowed by these notorious superbugs make them immune to these antibiotics subsequently causing our antibiotic wardrobe to be obsolete. In this unfortunate situation, though the time frame for discovering novel "hit molecules" down the line remains largely unknown, our small hope and untiring efforts injected in hunting novel chemical scaffolds with unique molecular targets using high-throughput technologies may safeguard us against these life-threatening challenges to some extent. Amid this crisis, the current comprehensive review highlights the present status of knowledge, our search for bacteria Achilles' heel, distinct molecular signaling that an opportunistic pathogen bestows to trespass the toxicity of antibiotics, and facile strategies and appealing therapeutic targets of novel drugs. Herein, we also discuss multidimensional strategies to combat antimicrobial resistance.

Antibiotic prescriptions in pediatric dentistry: A review

Most commonly prescribed drugs in pediatric dentistry are “Antibiotics.” Among Dentists, there is a trend toward overuse of antibiotics for nonindicated clinical conditions. This insufficient knowledge of the appropriate clinical indications for antibiotic prescriptions promotes the overuse of antibiotics and contributes to the emergence of antibiotic resistance among children. According to the various surveys done on the dental students, dentists and pediatric dentists on the antibiotic prescribing practices, overall, adherence to the professional clinical guidelines was low. There was a wide variation in dosages for all the antibiotics prescribed and for prolonged periods which were inconsistent with the recommendations. This paper reviews the current literature from the year 2000 to 2019. An electronic literature search was conducted in MEDLINE/PubMed, EBSCO host, and Google Scholar databases. The data was also collected manually from comprehensive textbooks. Some recommendations were also based on the opinion of experienced researchers and clinicians. Thus, this review aims at highlighting clinical indications, dosages, and duration of therapeutic antibiotic prescriptions for orofacial infections in the pediatric outpatients and at the same time creating an awareness, regarding the necessity of strictly adhering to the clinical guidelines for antibiotic prescriptions.

Role of Dentists in Prescribing Opioid Analgesics and Antibiotics: An Overview

Opioid analgesics and antibiotics prescribed by dentists is a useful and cost-effective measure when prescribed appropriately. Common dental conditions are best managed by extracting the offending tooth, restoring the tooth with an appropriate filling material, performing root canal therapy, and/or fabricating a prosthesis for the edentulous space. Unnecessary prescription of opioid analgesics and antibiotics to treat dental pain and bacterial infection is a growing public health concern. This article highlights the state of the literature on opioid analgesic and antibiotic prescribing practices in dentistry, the impact of opioid analgesic overdose, and prevention strategies to reduce opioid analgesics and antibiotic overprescription.

Effects of Antimicrobial Photodynamic Therapy and Local Administration of Minocycline on Clinical, Microbiological, and Inflammatory Markers of Periodontal Pockets: A Pilot Study

Objective

We evaluated the efficacies of antimicrobial photodynamic therapy (aPDT) and minocycline ointment (MO) on clinical and bacteriological markers and the local host inflammatory response.

Materials and Methods

A total of 30 patients with chronic periodontitis were randomly assigned to two groups. Selected periodontal pockets (probing depth 5-7 mm with bleeding on probing) were treated with aPDT or MO. Measurements of clinical parameters and the collection of gingival crevicular fluid (GCF) and subgingival plaque were performed at baseline, and at 1 and 4 weeks after treatment. Quantification of periodontopathic bacteria in the sulcus and a multiplex bead immunoassay of ten inflammatory cytokines in the GCF were performed.

Results

Local MO administration exhibited a significant decrease in scores for clinical parameters (P < 0.01) and a significant reduction in bacterial counts (P < 0.01) and interleukin-1β and interferon-γ levels at 1 and 4 weeks after treatment (P < 0.01). No significant changes were observed in the aPDT group, except in clinical parameters.

Conclusions

Although our study had some limitations, we found that while local administration of MO may slightly help to improve clinical, microbiological, and crevicular cytokine levels in periodontal pockets, aPDT did not show any effects. This trial is registered with the UMIN Clinical Trials Registry UMIN000013376.

Screening the Drug Resistance Property Among Aerobic Pathogenic Microorganisms of Dental Caries in North-Western Indian Population: A Preliminary Study

AIMS AND OBJECTIVES

To evaluate the emerging drug resistance among the caries pathogens isolated from carious dentine microbiologically.

MATERIALS AND METHODS

Specimens from dental caries were collected from 75 patients referred to Department of Conservative Dentistry and Endodontics, Vyas Dental College. Microbiological processing of all the samples was done within three hours to isolate the caries pathogens. The samples were inoculated on agar medium (Nutrient agar, Mac-conkey's agar) at 370C for 48 hours aerobically. The identification of strains was done by observing colony morphology and gram's staining. The predominant isolates were subjected to antimicrobial sensitivity test (Kirby Bauer's method). Statistical analysis of the isolates was done using paired t-test.

RESULTS

Out of 75 patients more common isolates were Staphylococcus aureus, Klebsiella, Pseudomonas aeruginosa, Yeast. The predominant were Staphylococcus and Pseudomonas species. Newer antibiotics were proved to be effective against these predominant strains after evaluating antibiotic sensitivity tests.

CONCLUSION

Although Streptococcus mutans (S.mutans) is the most prevalent microorganism seen in dental caries, the role of other microorganisms like Staphylococcus, Pseudomonas in initiation and progression of caries is evident from this study. Further extensive and large scale studies need to be conducted for better understanding the role of these microorganisms in dental caries.

Isolation and Antimicrobial Resistance ofStaphylococcus aureusIsolates in a Dental Clinic Environment

Objective.

To determine the number ofStaphylococcus aureusisolates collected in a dental clinical environment and to determine their susceptibility to antimicrobial agents commonly used in dentistry.

Setting.

Undergraduate clinic of the Dental School of Piracicaba, University of Campinas, Brazil.

Methods.

Sterile cotton swabs were used to collect the samples from dental-chair push buttons, light handles, 3-in-l syringes, computer “Enter” keys, doorknobs, and X-ray tubes before, during, and after clinical procedures. These samples were spread on brain-heart infusion agar and were incubated at 37°C for 24 hours. The resultingS. aureusisolates were counted and classified using Gram staining and biochemical tests. The counts among the 3 periods and the groups were analyzed by Kruskal-Wallis and Dunn tests (α= 5%). Commercial paper disks containing widely prescribed antimicrobial agents (β-lactams, macrolides, clindamycin, and vancomycin) were used to perform the antimicrobial susceptibility tests.

Results.

An increase in the number of microorganisms was observed during clinical procedures (P< .05). The highest bacterial resistance rates were observed for theβ-lactam group. All isolated strains were sensitive to vancomycin, and 2% of them were resistant to methicillin.

Conclusions.

Clinical procedures increased the number and proportion of antimicrobial-resistantS. aureusisolates dispersed in a dental clinical environment. The present study highlights the need to establish strategies to prevent emergence of drug-resistant bacterial strains in dental settings.

Surgical complications after implant placement

Placement of dental implants in the maxillofacial region is routine and considered safe. However, as with any surgical procedure, complications occur. Many issues that arise at surgery can be traced to the preoperative evaluation of the patient and assessment of the underlying anatomy. In this article, the authors review some common and uncommon complications that can occur during and shortly after implant placement. The emphasis of each section is on the management and prevention of complications that may occur during implant placement.

Antibiotics in dental practice: how justified are we

Antibiotics are prescribed by dentists in dental practice, during dental treatment as well as for prevention of infection. Indications for the use of systemic antibiotics in dentistry are limited because most dental and periodontal diseases are best managed by operative intervention and oral hygiene measures. The use of antibiotics in dental practice is characterised by empirical prescription based on clinical and bacteriological epidemiological factors, resulting in the use of a very narrow range of broad-spectrum antibiotics for short periods of time. This has led to the development of antimicrobial resistance (AMR) in a wide range of microbes and to the consequent inefficacy of commonly used antibiotics. Dentists can make a difference by the judicious use of antimicrobials--prescribing the correct drug, at the standard dosage and appropriate regimen--only when systemic spread of infection is evident. The increasing resistance problems of recent years are probably related to the over- or misuse of broad-spectrum agents. There is a clear need for the development of prescribing guidelines and educational initiatives to encourage the rational and appropriate use of drugs in dentistry. This paper highlights the need for dentists to improve antibiotic prescribing practices in an attempt to curb the increasing incidence of antibiotic resistance and other side effects of antibiotic abuse. The literature provides evidence of inadequate prescribing practices by dentists for a number of factors, ranging from inadequate knowledge to social factors.

Clinical and Microbiological Effects of Photodynamic Therapy Associated with Non-surgical Treatment in Aggressive Periodontitis

Background and aims. The aim of this study was to compare the effectiveness of adjunctive photodynamic therapy (PDT) in the treatment of aggressive periodontitis.

Materials and methods. A total of 24 patients with clinical diagnosis of aggressive periodontitis received scaling and root planing (SRP) for periodontal treatment. In a split-mouth design study, the teeth of one quadrant of each arch with ≥4 mm of probing depth were selected randomly for additional treatment with PDT (test group). PDT was performed with a diode laser beam with a wavelength of 670-690 nm and a power of 75 Mw. The control group consisted of selected teeth of the contralateral quadrant (SRP only). Before any treatment, subgingival plaque samples were collected by an endodontic paper cone for microbiological analysis by real-time polymerase chain reaction (PCR) for detection of Aggregatibacter actinomycetecommitans. Clinical parameters including clinical attachment loss (CAL) as primary outcome, plaque index (PI), bleeding on probing (BOP), probing depth (PD) and gingival recession (REC) were measured at baseline and after 90 days. Inter-group and intra-group statistical analyses were performed.

Results. Treatment groups showed an improvement in all the clinical parameters and a significant reduction in the counts of A. actinomycetecommitans at 90 days compared to baseline (P < 0.05). None of the periodontal parameters exhibited significant differences between the two groups (P > 0.05).

Conclusion. Within the limitations of this study, the results did not show additional benefits from PDT as an adjunctive treatment for patients with aggressive periodontitis.

Barriers to the effective treatment of sepsis: antimicrobial agents, sepsis definitions, and host-directed therapies

Sepsis is a complex clinical syndrome involving both infection and a deleterious host immune response. Antimicrobial agents are key elements of sepsis treatment, yet despite great strides in antimicrobial development in the last decades, sepsis continues to be associated with unacceptably high mortality (~30%). This is the result, on one hand, of the rise of antimicrobial resistant organisms and, on the other hand, of the dearth of effective host-directed immune therapies. A major obstacle to the development of good host-directed therapies is the lack of understanding of the host immune response. The problem is exacerbated by poor nonspecific clinical definitions of disease. Poor definitions have had a profound impact on sepsis research, from epidemiologic studies to the failed clinical trials of host-directed therapies. Therefore, better definitions must be developed to enable advancement in the field.

In silico analysis of antibiotic resistance genes in the gut microflora of individuals from diverse geographies and age-groups

The spread of antibiotic resistance, originating from the rampant and unrestrictive use of antibiotics in humans and livestock over the past few decades has emerged as a global health problem. This problem has been further compounded by recent reports implicating the gut microbial communities to act as reservoirs of antibiotic resistance. We have profiled the presence of probable antibiotic resistance genes in the gut flora of 275 individuals from eight different nationalities. For this purpose, available metagenomic data sets corresponding to 275 gut microbiomes were analyzed. Sequence similarity searches of the genomic fragments constituting each of these metagenomes were performed against genes conferring resistance to around 240 antibiotics. Potential antibiotic resistance genes conferring resistance against 53 different antibiotics were detected in the human gut microflora analysed in this study. In addition to several geography/country-specific patterns, four distinct clusters of gut microbiomes, referred to as ‘Resistotypes’, exhibiting similarities in their antibiotic resistance profiles, were identified. Groups of antibiotics having similarities in their resistance patterns within each of these clusters were also detected. Apart from this, mobile multi-drug resistance gene operons were detected in certain gut microbiomes. The study highlighted an alarmingly high abundance of antibiotic resistance genes in two infant gut microbiomes. The results obtained in the present study presents a holistic ‘big picture’ on the spectra of antibiotic resistance within our gut microbiota across different geographies. Such insights may help in implementation of new regulations and stringency on the existing ones.

Inhibition of biofilm formation and antibacterial properties of a silver nano-coating on human dentine

The survival of pathogenic bacteria in the oral cavity depends on their successful adhesion to dental surfaces and their ability to develop into biofilms, known as dental plaque. Bacteria from the dental plaque are responsible for the development of dental caries, gingivitis, periodontitis, stomatitis and peri-implantitis. Certain metal nanoparticles have been suggested for infection control and the management of the oral biofilm. Here, it is shown that application of a silver nano-coating directly on dentine can successfully prevent the biofilm formation on dentine surfaces as well as inhibit bacterial growth in the surrounding media. This silver nano-coating was found to be stable (>98.8%) and to maintain its integrity in biological fluids. Its antibacterial activity was compared to silver nitrate and the widely used clinical antiseptic, chlorhexidine. The bacterial growth and cell viability were quantitatively assessed by measuring the turbidity, proportion of live and dead cells and lactate production. All three bioassays showed that silver nanoparticles and silver nitrate dentine coatings were equally highly bactericidal (>99.5%), while inhibiting bacterial adhesion. However, the latter caused significant dentine discolouration (ΔE* = 50.3). The chlorhexidine coating showed no antibacterial effect. Thus, silver nanoparticles may be a viable alternative to both chlorhexidine and silver nitrate, protecting from dental plaque and secondary caries when applied as a dentine coating, while they may provide the platform for creating anti-biofilm surfaces in medical devices and other biomedical applications.

Antimicrobial effect of photodynamic therapy using high-power blue light-emitting diode and red-dye agent on Porphyromonas gingivalis

BACKGROUND AND OBJECTIVE

Antimicrobial photodynamic therapy (a-PDT) using a combination of red-colored laser/light-emitting diode (LED) and blue dye has been employed for periodontal therapy and the antimicrobial effect seems promising. Blue light, which has favorable wavelength properties, would be more effective as a light source for a-PDT because blue light itself possesses an antimicrobial effect. This study aimed to investigate the effect of a-PDT using a novel combination of high-power blue LED and red-dye agent on Porphyromonas gingivalis in vitro.

MATERIAL AND METHODS

Porphyromonas gingivalis ATCC 33277 suspension was irradiated with blue LED (BL) (425-470 nm) or red LED (RL) (625-635 nm) at 30-90 J/cm(2) , or was mixed with erythrosine (ER), phloxine B (PB) or rose bengal (RB) with or without BL irradiation (30 J/cm(2) ). RL (30 J/cm(2) ) in combination with toluidine blue was employed as positive control. All the suspensions of P. gingivalis were serially diluted, plated and incubated anaerobically, and the numbers of colony-forming units (CFUs) were counted on day 7.

RESULTS

BL irradiation at 60 and 90 J/cm(2) demonstrated a significant reduction in the numbers of CFUs. ER, PB and RB solutions at 160 μg/mL showed almost no or only a minimal reduction in the numbers of CFUs. BL at 30 J/cm(2) combined with ER, PB or RB at 160 μg/mL resulted in a log reduction of 0.9, 1.0 and 7.1, respectively, in the numbers of CFUs; 30 J/cm(2) BL with RB at 1.6, 16 and 160 μg/mL demonstrated a log reduction of 6.3, 8.0 and 5.5, respectively; and a log reduction of 5.2 was obtained after 30 J/cm(2) RL with 16 μg/mL TB.

CONCLUSION

Within the limits of this study, BL was found to have an antimicrobial/growth-inhibiting effect on P. gingivalis, and a-PDT using a combination of BL and RB shows promise as a new technical modality for bacterial elimination in periodontal therapy.

Effect of hydrosoluble chlorine-mediated antimicrobial photodynamic therapy on clinical parameters and cytokine profile in ligature-induced periodontitis in dogs

BACKGROUND

Recently, a hydrosoluble chlorine composed of sodium salts chlorine e6, chlorine p6, and purpurine-5 has been shown to be a promising photosensitizer in antimicrobial photodynamic therapy (aPDT). The aim of this study is to evaluate the effects of adjunctive application of hydrosoluble chlorine-mediated aPDT compared with scaling and root planing (SRP) alone on clinical parameters and cytokine levels in gingival crevicular fluid of dogs with experimental periodontitis.

METHODS

Periodontal disease was induced by placing silk ligatures around both maxillary and mandibular teeth. After establishment of attachment loss, full-mouth SRP was performed in all dogs. One day after SRP, each quadrant randomly received one of the following treatment modalities: hydrosoluble chlorine plus diode laser (wavelength 662 nm, power 100 mW, continuous mode, time of irradiation 20 seconds), hydrosoluble chlorine alone, laser alone, or no adjunctive treatment. The same adjunctive procedure was repeated 1 week later. Clinical parameters including periodontal probing depth, clinical attachment level, and bleeding on probing, as well as crevicular levels of interleukin-1β and tumor necrosis factor-α, were evaluated at baseline, at 3 weeks, and at 3 months after treatment.

RESULTS

After both 3 weeks and 3 months, all treatment groups showed significant improvement in all clinical and immunologic parameters (P <0.001). No significant differences were found between the four groups with regard to the measured parameters (P >0.05).

CONCLUSION

Based on the results of this study, adjunctive use of hydrosoluble chlorine-mediated aPDT with the current setting has no additional effect on the clinical parameters or proinflammatory cytokine levels in ligature-induced periodontitis.

Impact of an antibiotic restriction program on antibiotic utilization in the treatment of community-acquired pneumonia in a Veterans Affairs Medical Center

PURPOSE

The impact of an antibiotic restriction program (ARP) on the patterns of antibiotic use in the treatment of community-acquired pneumonia (CAP) was examined. We also evaluated the association between the ARP and the length of hospital stay in regard to CAP treatment and cost savings associated with the implementation of the ARP.

METHODS

A retrospective cohort study of patients admitted with CAP was conducted during two 6-month periods, one prior to the ARP and one after the ARP. The health system's computerized patient record system (CPRS) was used to obtain demographics, length of hospital stays, readmission rates, blood culture results, co-morbidities, antibiotic use, and durations of therapy. A total of 130 patients met the inclusion criteria for the final analyses. Average drug costs, employee salaries, and the cost of laboratory procedures were used to assess cost savings associated with the ARP.

RESULTS

From a total of 132 antibiotics that were ordered to treat CAP in the pre-ARP period, 28 were restricted (21.2%). However, the number of restricted antibiotics ordered was significantly reduced to 12 out of 114 (10.2%) antibiotics ordered in the post-ARP period (P = 0.024). In post-ARP implementation, the mean length of hospital stay was also significantly reduced from 7.6 to 5.8 days (P = 0.017), and although not statistically significant, the 30-day readmission rates declined from 16.9 to 6.2% (P = 0.097). The ARP was also associated with a saving of $943 per patient treated for CAP.

CONCLUSIONS

In addition to a decrease in the antibiotic utilization and the mean length of hospital stay, the ARP may have yielded cost savings and reduced the readmission rates for those patients admitted and treated for CAP.

Antibiotic prescribing practices by dentists: a review

Antibiotics are prescribed by dentists for treatment as well as prevention of infection. Indications for the use of systemic antibiotics in dentistry are limited, since most dental and periodontal diseases are best managed by operative intervention and oral hygiene measures. However, the literature provides evidence of inadequate prescribing practices by dentists, due to a number of factors ranging from inadequate knowledge to social factors. Here we review studies that investigated the pattern of antibiotic use by dentists worldwide. The main defects in the knowledge of antibiotic prescribing are outlined. The main conclusion is that, unfortunately, the prescribing practices of dentists are inadequate and this is manifested by over-prescribing. Recommendations to improve antibiotic prescribing practices are presented in an attempt to curb the increasing incidence of antibiotic resistance and other side effects of antibiotic abuse.

A targeting approach for delivery of polymer microparticle-antibody conjugate againstVibrio parahaemolyticus-induced cytotoxicity to human intestinal epithelial cells

A major traditional of antibacterial drugs is antibiotic which promotes more rapid release of the toxins from bacteria cells in human body, which causes severe infection. The thermostable direct hemolysin (TDH) has been proposed as a major virulence factor of Vibrio parahaemolyticus (Vp). This study covers the preparation of polymer microparticle-antibody conjugate for the development of a drug targeting approach for antibacterial drug delivery. The chemical binding of antibodies (ab) to latex bead of 0.2 mum diameter was performed by using a water-soluble carbodiimide technique. Confocal microscopy revealed that the bacteria were strongly absorbed by the latex beads with bound anti-Vp polyclonal antibody (pAb). Treatment with a latex bead bound both anti-Vp pAb and anti-TDH monoclonal antibody (mAb) significantly inhibited bacterial adherence to the Caco-2 cells (p < 0.01), and reduced TDH-induced cytotoxicity in histology. These preliminary results suggest that it may be possible to effectively protect against Vp infection by using this microparticle-antibody conjugate delivery system.

Low-dose doxycycline inhibits bone resorption associated with apical periodontitis

AIM

To test the effect of low-dose doxycycline on bone resorption associated with apical periodontitis.

METHODOLOGY

Apical periodontitis was induced by occlusal pulp exposure in the mandibular first molars of 36 rats. Animals were divided into three groups of 12: group A received doxycycline in drinking water at a dose of 5.85 mg day(-1); group B received a dose of 1.48 mg day(-1) (one-quarter of the original dose); and group C received no medicament and served as the control. A bioassay determined the doxycycline serum levels. After 21 days, the mandibles were removed, radiographed and the radiographs scanned to generate digital images. These images were analysed morphometrically and the total area of the periapical bone resorption of the mesial and distal roots of each tooth was determined and used to compare the groups. Statistical analysis was completed using anova with repeated measures.

RESULTS

The mean doxycycline serum level in group A was 0.22(+/-0.03) microg mL(-1) and in group B below the detection level of the assay (<0.062 microg mL(-1)). The mean area of the periapical bone resorption in the control group C was 2.91(+/-0.61) mm(2). In animals treated with a low-dose doxycycline, the mean size of the bone resorption was significantly smaller at 1.59(+/-0.59) mm(2) (group A) and 1.72(+/-0.85) mm(2) (group B) (P = 0.001). No significant difference was found in the area of the bone resorption between these two groups A and B.

CONCLUSIONS

Low-dose doxycycline reduced the area of bone resorption associated with apical periodontitis in the mandibular first molar teeth of rats.

Antimicrobial Photodynamic Therapy in the Non-Surgical Treatment of Aggressive Periodontitis: A Preliminary Randomized Controlled Clinical Study

BACKGROUND

The treatment of aggressive periodontitis has always presented a challenge for clinicians, but there are no established protocols and guidelines for the efficient control of the disease.

METHODS

Ten patients with a clinical diagnosis of aggressive periodontitis were treated in a split-mouth design study to either photodynamic therapy (PDT) using a laser source with a wavelength of 690 nm associated with a phenothiazine photosensitizer or scaling and root planing (SRP) with hand instruments. Clinical assessment of plaque index (PI), gingival index (GI), bleeding on probing (BOP), probing depth (PD), gingival recession (GR), and relative clinical attachment level (RCAL) were made at baseline and 3 months after treatment with an automated periodontal probe.

RESULTS

Initially, the PI was 1.0 +/- 0.5 in both groups. At the 3-month evaluation, the plaque scores were reduced and remained low throughout the study. A significant reduction of GI and BOP occurred in both groups after 3 months (P <0.05). The mean PD decreased in the PDT group from 4.92 +/- 1.61 mm at baseline to 3.49 +/- 0.98 mm after 3 months (P <0.05) and in SRP group from 4.92 +/- 1.14 mm at baseline to 3.98 +/- 1.76 mm after 3 months (P <0.05). The mean RCAL decreased in the PDT group from 9.93 +/- 2.10 mm at baseline to 8.74 +/- 2.12 mm after 3 months (P <0.05), and in the SRP group, from 10.53 +/- 2.30 mm at baseline to 9.01 +/- 3.05 mm after 3 months.

CONCLUSION

PDT and SRP showed similar clinical results in the non-surgical treatment of aggressive periodontitis.

Discrepancy in antimicrobial susceptibility test results obtained for oral streptococci with the Etest and agar dilution

A total of 270 viridans group streptococci (VS) isolated from healthy children, identified to the species level, were tested for their susceptibilities to penicillin, imipenem, erythromycin, and vancomycin. A total of 270 isolates and 1,080 organism-antibiotic combinations were evaluated. The overall susceptibility rates of all isolates obtained by the Etest (ET) versus agar dilution (AD) were 60.4% versus 61.8% for penicillin, 63.8% versus 63.9% for erythromycin, 90.6% versus 96% for vancomycin, and 99.1% versus 96.0% for imipenem, respectively. Major discrepancies occurred in the testing of the susceptibility of Streptococcus mutans to vancomycin, with 59.5% (ET) versus 100% (AD), followed by S. salivarius, with 84.1% versus 100%; S. oralis, with 82.1% versus 96.4%; and S. mitis, with 90% versus 100%, respectively. There were also differences in the rates of susceptibility of S. mutans, 66.5% (ET) versus 85.1% (AD), and S. intermedius, 82.9% versus 72.1%, respectively, to penicillin. General agreement between the results of ET and AD was obtained for 973 organism-antibiotic combinations out of 1,080 antibiotic combinations, i.e., 90.1%. Very major errors were found for 6.8% of isolates, and major errors were found for 3.2% of isolates; the minor errors were negligible. Agreement between the results of the two methods was 98.7% for penicillin, 94.6% for vancomycin, 96.9% for imipenem, and 99.9% for erythromycin. The highest rate of very major errors was for vancomycin, at 5.4%. The ET appears to be as efficient as AD for susceptibility testing of VS, except for vancomycin, where very major errors in the results were relatively high.

Incidence of antibiotic prescribing in dental practice in Norway and its contribution to national consumption

OBJECTIVES

To assess dentistry-based utilization of the 11 antibiotics prescribed by dentists in Norway and its relative contribution to national outpatient consumption and to determine the relationship between numbers of prescriptions and the consumption of these antibiotics.

METHODS

Data on national antibiotic prescriptions by dentists in 2004 and 2005 were used. Consumption of the antibiotics was expressed using WHO defined daily doses (DDDs), DDDs per 1000 inhabitants per day (DIDs) and numbers of prescriptions per 1000 inhabitants (PIDs).

RESULTS

Analysis of 268,834 prescriptions issued by 4765 dentists showed that the dentists' prescriptions contributed 8% of the total national consumption of the 11 antibiotics and 13.5%, 2.8% and 1.2% of the national beta-lactam penicillins, macrolides and lincosamides and tetracyclines utilization, respectively. The dentists' contributions to the national phenoxymethylpenicillin, spiramycin and metronidazole consumptions were considerably higher (> or =13.2%) than for the other prescribed antibiotics (< or =8.6%). There was a strong positive correlation between numbers of DDDs and numbers of prescriptions and between DIDs and numbers of PIDs.

CONCLUSIONS

Reliance of Norwegian dentists on phenoxymethylpenicillin as their first choice suggests a low prevalence of antibiotic resistance among oral bacteria in Norway. Norwegian dentists prefer to prescribe narrow-spectrum antibiotics; their prescribing is conservative and relatively low compared with that of physicians.

The prevalence and antibiotic sensitivity of oral Viridans streptococci in healthy children and children with disabilities in Kuwait

The purpose of this study was to compare the antibiotic susceptibility profiles of Viridans streptococci (VS) isolated from the oral cavity of healthy children and children with disabilities in Kuwait. Plaque samples were collected from the tooth and tongue surfaces of 102 healthy children and 102 children who were intellectually disabled and institutionalized. The resistance to seven antibiotics (amoxicillin, cephalothin, clindamycin, erythromycin, penicillin G, tetracycline, and vancomycin) was tested. A total of 330 (44.5%) VS were isolated from the children who were healthy and 411 (55.5%) from children with disabilities. The most common isolates were S. salivarius (27.3%) in healthy children; S. sanguis (22.6%) was predominant among children who were disabled. S. mutans was found in 12.1% of the healthy children and in 16.5% of the children who were disabled. The combined percentage of resistant strains (healthy and disabled) was found to be highest with amoxicillin (43%) and lowest with vancomycin (12%). S. sanguis, S. mitis and S. oralis were more resistant in healthy children (45%, 56%, and 55% respectively) than in children with disabilities (40%, 47% and 47% respectively). S. mutans was the least resistant species to all antibiotics in both groups of children. About 56% of all streptococci isolated from both groups were resistant to at least one of the antibiotics tested. The data showed that there was a difference in the level of resistance of oral VS isolated from healthy children and children with disabilities to some antibiotics commonly used in dentistry.

Knowledge of prescribing antimicrobials among Yemeni general dentists

OBJECTIVE

Overuse of antimicrobial agents is closely related to an increase in bacterial resistance. A sound knowledge of appropriate prescribing of antimicrobials among health professionals is thus critical in combating the resistance. The objectives of this study were to assess the rationale for and patterns of antimicrobial prescriptions by general dental practitioners in Yemen.

MATERIAL AND METHODS

A questionnaire containing 65 closed questions was used for this cross-sectional study and distributed to 280 dentists in the three major governorates in Yemen. The anonymously completed questionnaires sought answers to demographic questions and to questions on the therapeutic and prophylactic use of antimicrobial agents in dentistry. Correct and incorrect answers were defined according to information available in the current authoritative literature. Each correct answer was given a score of 1 while an incorrect answer scored 0. Thus, the total score had an attainable range from 0 to 65. Frequencies, means, and associations were assessed statistically.

RESULTS

Out of 181 collected forms (response rate 64.6%), 150 were appropriately completed and used for data analyses. Penicillins were the most frequently prescribed drugs (72%), followed by spiramycin (10%). It was found that up to 84% of practitioners were likely to prescribe an antimicrobial agent when there was no clinical indication for such a medication. Many respondents (70%) would consider antibiotics for at least one of the given non-clinical factors.

CONCLUSIONS

The results suggest that dental practitioners in Yemen lack uniformity in the rationale for appropriate prescribing of antimicrobials to their patients. Consequently, to reduce overuse, there is an urgent need for the dental community in the country to be informed about evidence-based guidelines and the appropriate use of antimicrobial agents in clinical dental practice.

Efficacy of photodynamic therapy on inflammatory signs and two selected periodontopathogenic species in a beagle dog model

BACKGROUND

Current research aims to find alternatives to conventional methods for suppressing periodontopathogenic bacteria. Photodynamic therapy (PDT) could be a suitable treatment procedure of periodontal infections.

METHODS

In the present study, the PDT method was tested with two photosensitizers, chlorine e6 and BLC1010, in an experiment on beagle dogs. The animals were infected with Porphyromonas gingivalis (Pg) and Fusobacterium nucleatum (Fn) in all subgingival areas. After infection, we observed clinical signs of gingival inflammation, including an increase of redness and bleeding on probing. Microbiological monitoring before and after treatment was performed using polymerase chain reaction (PCR). PDT was conducted with a diode laser with a wavelength of 662 nm using a power of 0.5 W and the photosensitizers.

RESULTS

The PDT procedure carried out with either of the photosensitizers caused a significant reduction in the clinical inflammation signs of redness and BOP, compared to the controls (laser only and no treatment). Furthermore, PDT with chlorine e6 caused a significant reduction in P. gingivalis-infected sites, whereas there was a lack in suppression after PDT with BLC1010. F. nucleatum could hardly be reduced with chlorine e6, and only to a certain extent with BLC 1010 and laser only. In the control groups, the Pg-infected test sites did not change.

CONCLUSIONS

This study demonstrated that the photodynamic therapy using photosensitizer and a 662 nm laser light source is distinctly advantageous in reducing the periodontal signs of redness and bleeding on probing. The procedure also appears to significantly suppress P. gingivalis.

Dentistry and endocarditis

Bacterial endocarditis (BE), a rare heart infection caused by a bacteremia, has frequently been blamed on but rarely caused by dental procedures. Viridans group streptococci are found abundantly in the mouth and the gingival sulcus but have been surpassed by staphylococci as the leading cause of BE. Antibiotic prophylaxis has been recommended before dental procedures in patients at risk for BE, but it remains controversial because studies have failed to show that antibiotic prophylaxis is an effective preventive for BE or that dental procedures are an important cause of BE. The risks and costs of antibiotic prophylaxis, including antibiotic resistance, cross-reactions with other drugs, allergy, anaphylaxis, and even death, may exceed the benefits in preventing BE. The rationale for the use of antibiotic prophylaxis to prevent BE allegedly caused by dental procedure bacteremias must be seriously reexamined based on recent evidence, particularly the absolute risk rates for endocarditis after a given dental procedure.

Genetic examination of children suffering from cystic fibrosis

CFTR protein (cystic fibrosis trans membrane conductance regulator) is expressed in multiple epithelial tissues, including upper and lower respiratory tracts, pancreas, sweat glands and gastrointestinal tract. More than 800 mutations and 100 polymorphic variants of DNA sequences were identified in patients with CF (Cystic fibrosis) and CFTR-diseases. In this study, genetic CFTR analysis of the children suffering from chronic lung disease (cystic fibrosis) is presented. They are treated and regularly controlled at the Pediatric hospital Sarajevo. CFTR analysis was done in 9 cases, 4 boys (44.4%) and 5 girls (55.55%). There are 3 children (33.3%) in the age group 1 to 3 years, 1 child (11.1%) in the age group 3 to 6 years, 3 children (33.3%) in the age group 6 to 9 years and 2 children (22.2%) in the age group 9 to 12 years. Genetic analysis was conducted at the Medical center for molecular biology, School of Medicine, Ljubljana. PCR method with PAGE and direct sequestration on ABI PRISM 31 was applied. The majority of children (7 children, i.e. 77.77%) had CFTR mutation Delta F 508 whilst one child had G542X mutation and one child R 1174 mutation. The purpose of this study is to emphasize the need for CFTR gene identification in the institutes of our country.