Non-antibiotic Treatment Research Articles

Phosphorylation-dependent and Phosphorylation-independent Regulation of Helicobacter pylori Acid Acclimation by the ArsRS Two-component System.

The pH-sensitive Helicobacter pylori ArsRS two-component system (TCS) aids survival of this neutralophile in the gastric environment by directly sensing and responding to environmental acidity. ArsS is required for acid-induced trafficking of urease and its accessory proteins to the inner membrane, allowing rapid, urea-dependent cytoplasmic and periplasmic buffering. Expression of ArsR, but not its phosphorylation, is essential for bacterial viability. The aim of this study was to characterize the roles of ArsS and ArsR in the response of H. pylori to acid. Wild-type H. pylori and an arsR(D52N) phosphorylation-deficient strain were incubated at acidic or neutral pH. Gene and protein expression, survival, membrane trafficking of urease proteins, urease activity, and internal pH were studied. Phosphorylation of ArsR is not required for acid survival. ArsS-driven trafficking of urease proteins to the membrane in acid, required for recovery of internal pH, is independent of ArsR phosphorylation. ArsR phosphorylation increases expression of the urease gene cluster, and the loss of negative feedback in a phosphorylation-deficient mutant leads to an increase in total urease activity. ArsRS has a dual function in acid acclimation: regulation of urease trafficking to UreI at the cytoplasmic membrane, driven by ArsS, and regulation of urease gene cluster expression, driven by phosphorylation of ArsR. ArsS and ArsR work through phosphorylation-dependent and phosphorylation-independent regulatory mechanisms to impact acid acclimation and allow gastric colonization. Furthering understanding of the intricacies of acid acclimation will impact the future development of targeted, nonantibiotic treatment regimens.

A Combination of Three Fully Human Toxin A- and Toxin B-Specific Monoclonal Antibodies Protects against Challenge with Highly Virulent Epidemic Strains of Clostridium difficile in the Hamster Model.

Clostridium difficile infection (CDI) is the principal cause of nosocomial diarrhea and pseudomembranous colitis associated with antibiotic therapy. Recent increases in the number of outbreaks attributed to highly virulent antibiotic-resistant strains underscore the importance of identifying efficacious alternatives to antibiotics to control this infection. CDI is mediated by two large exotoxins, toxins A and B. Strong humoral toxin-specific immune responses are associated with recovery and a lack of disease recurrence, whereas insufficient humoral responses are associated with recurrent CDI. Multiple approaches targeting these toxins, including intravenous immunoglobulin, neutralizing polymers, active vaccines, and, most recently, monoclonal antibodies (MAbs), have been explored, with various degrees of success. In this study, we describe the characterization of the first MAbs isolated from healthy human donors using a high-throughput B-cell cloning strategy. The MAbs were selected based on their ability to inhibit the actions of toxins A and B in vitro and because of their in vivo efficacy in a hamster challenge model. A potent 2-MAb cocktail was identified and then further potentiated by the addition of a second anti-toxin B MAb. This 3-MAb combination protected animals against mortality and also reduced the severity and duration of diarrhea associated with challenge with highly virulent strains of C. difficile toxinotypes 0 and III. This highly efficacious cocktail consists of one MAb specific to the receptor binding domain of toxin A and two MAbs specific to nonoverlapping regions of the glucosyltransferase domain of toxin B. This MAb combination offers great potential as a nonantibiotic treatment for the prevention of recurrent CDI.

Toxin synthesis by Clostridium difficile is regulated through quorum signaling.

ABSTRACTClostridium difficile infection (CDI) is dramatically increasing as a cause of antibiotic- and hospital-associated diarrhea worldwide. C. difficile, a multidrug-resistant pathogen, flourishes in the colon after the gut microbiota has been altered by antibiotic therapy. Consequently, it produces toxins A and B that directly cause disease. Despite the enormous public health problem posed by this pathogen, the molecular mechanisms that regulate production of the toxins, which are directly responsible for disease, remained largely unknown until now. Here, we show that C. difficile toxin synthesis is regulated by an accessory gene regulator quorum-signaling system, which is mediated through a small (<1,000-Da) thiolactone that can be detected directly in stools of CDI patients. These findings provide direct evidence of the mechanism of regulation of C. difficile toxin synthesis and offer exciting new avenues both for rapid detection of C. difficile infection and development of quorum-signaling-based non-antibiotic therapies to combat this life-threatening emerging pathogen.

Plasmonic photothermal destruction of uropathogenic E. coli with reduced graphene oxide and core/shell nanocomposites of gold nanorods/reduced graphene oxide.

The development of non-antibiotic based treatments against bacterial infections by Gram-negative uropathogenic E. coli is a complex task. New strategies to treat such infections are thus urgently needed. This report illustrates the development of pegylated reduced graphene oxide nanoparticles (rGO-PEG) and gold nanorods (Au NRs) coated with rGO-PEG (rGO-PEG-Au NRs) for the selective killing of uropathogenic E. coli UTI89. We took advantage of the excellent light absorption properties of rGO-PEG and Au NR particles in the near-infrared (NIR) region to photothermally kill Gram-negative pathogens up to 99% in 10 min by illumination of solutions containing the bacteria. The rGO-PEG-Au NRs demonstrated better photothermal efficiency towards E. coli than rGO-PEG. Targeted killing of E. coli UTI89 could be achieved with rGO-PEG-Au NRs functionalized with multimeric heptyl α-d-mannoside probes. This currently offers a unique biocompatible method for the ablation of pathogens with the opening of probably a new possibility for clinical treatments of patients with urinary infections.

A Comparative Study of Topical Azailic Acid Cream 20% and Active Lotion Containing Triethyl Citrate and Ethyl Linoleate in the Treatment of Mild to Moderate Acne Vulgaris

Background: Acne vulgaris is a common disorder affecting 79% - 95% of the adolescent population. The choice of treatment depends on the severity, patients with mild to moderate acne should receive topical therapy such as azelaic acid. Rising antibiotic drug resistance consequent to the widespread use of topical antibiotics is causing concern and effective non-antibiotic treatments are needed. Objective: To compare the efficacy and side effects of topical azelaic acid cream 20% versus active lotion containing triethyl citrate and ethyl linoleate (TCEL) in treatment of mild to moderate acne vulgaris. Patients and Methods: This single, blinded, comparative, therapeutic study was done in the Department of Dermatology-Baghdad Teaching Hospital, Baghdad, Iraq; from May 2013-July 2014. Scoring of acne was carried out and the patients were examined every 2 weeks for 10 weeks of treatment. One month after stopping drugs, patients were evaluated for drug complications and disease recurrence. Sixty patients fulfilling enrollment criteria were included in this study. Patients were divided into 2 groups: Group A (30 patients) treated twice daily with TCEL lotion and Group B (30 patients) treated twice daily with topical azelaic acid cream 20%. Results: Both topical TCEL lotion and azelaic acid cream were statistically an effective therapy for treatment of mild to moderate acne vulgaris. TCEL lotion was more effective and act earlier than azelaic acid cream starting from 4 weeks of therapy till the end of treatment (after 10 weeks) and even after 4 weeks after stopping the treatment (P-value non-inflammatory acne lesions. Its use would reduce the risk of antibiotic resistance developing within the skin flora.

Reducing infection-related preterm birth.

A myriad of research papers have indicated that abnormal vaginal flora is a risk factor for preterm delivery. The most favored hypothesis for the mechanism is through ascending infection from the vagina, causing deciduitis and chorioamnionitis, inducing the cytokine and prostaglandin cascade and hence cervical weakening and contractions. In his contribution, Steve Witkin points to the matrix metalloproteinase (MMP)-8 and its inducer extracellular MMP inducer (EMMPRIN) as a key trigger to weaken the cervix and allow ascending commensal or potential pathogenic microorganisms, most often associated with bacterial vaginosis (BV), to cause intra-amniotic infection to occur. In conjunction with the l-lactate producing vaginal epithelium, the presence of Lactobacillus crispatus, Lactobacillus jenseni, and Lactobacillus gasseri, but not the BV-associated Lactobacillus iners, contributes to the protection of the vagina against this EMMPRIN activity by producing d-lactate, which decreases its release by the epithelium. This point is well taken and his suggestion to replace antibiotic therapy by lactic acid gel application to the vagina in women living in areas with poor resources and women with signs of disturbed flora could work. However, a few details may matter. That the production of vaginal lactic acid is closely correlated with the proportional level of other bacteria replacing the lactobilli (lactobacillary grades) has been known for decades, as well as the association of the latter with vaginal pro-inflammatory cytokine production, which fluctuates along the course of pregnancy. The results of Hoyme's original observational study of self-measuring vaginal pH, followed by treatment without proper diagnostic workout may have suggested a benefit in reducing preterm births, but this was not confirmed in a subsequent population-based controlled trial following 149 048 pregnant women in the same region (Bitzer et al. Dtsch Arztebl Int 2011;108:81–6). Analysing self-measurements of vaginal pH, although well accepted in poor resource countries such as Uganda, did not reflect the presence of BV in these women, as only 34% of women with increased pH had BV, the others having aerobic vaginitis (AV), endogeneous lack of lactobacilli or other conditions influencing pH (G.G.G Donders, F. Donders, G. Bellen, C. Depuydt, N. Eggermont, T. Michiels, J. Lule, J. Byamughisa, data on file). In this study the transitional state between normal flora and BV, called partial BV, had the same increased vaginal pH as full blown BV, whereas the so-called intermediate flora, representing a Nugent score 4–6 on gram-stained specimens, was found equally frequently in all pH groups. As this ‘intermediate flora’ according to Nugent represents not only partial BV, but also AV and other abnormalities, it is not surprising that it should also be considered a risk factor for preterm labour, as AV as well as partial BV may pose a greater risk for the pregnancy than full blown BV (Donders et al. BJOG 2009;116:1315–24). Hence it does not come as a surprise that meta-analyses have failed to show that metronidazole prevents preterm birth, as mentioned in the paper. Besides L. iners and Gardnerella vaginalis being general surrogate markers markers of BV, Mobiluncus and Atopobium vaginae are even stronger indicators of full-blown BV (Nugent score above 8), and are, remarkably, not responsive to metronidazole. Although they are notorious lactic acid producers, both organisms are independently linked to an increased preterm birth risk (Foxman et al. AJOG 2014;210:226–7). As reasoned by Dr Witkin, treatment with lactic acid in cases with a disturbed lactate d over lactate l ratio could be an option to help prevent preterm birth that requires further attention. However, preventive or curative non-antibiotic treatment options are not limited to the use of lactic acid gel and/or glycogen. Antiseptics, pH-lowering devices such as vitamin C, or probiotic agents can also restore resistant vaginal flora (Donders et al. Expert Opin Pharmacother 2014;15:645–57) and are currently being studied in low resource countries. None. Wrote the paper. Not applicable. None. None.

Intravesical treatment with highly-concentrated hyaluronic acid and chondroitin sulphate in patients with recurrent urinary tract infections: Results from a multicentre survey.

We assess the effectiveness of intravesical instillation of hyaluronic acid (HA) and chondroitin sulphate (CS) as a non-antibiotic treatment option for prophylaxis of recurrent urinary tract infections (UTIs) in female patients. This was a retrospective cohort study involving 7 European institutions. We included patients with recurrent UTIs who received intravesical instillations of Ialuril (IBSA International) (50 mL HA 1.6% and CS 2% solution) between January 2010 and March 2012. Medication schedule, length of follow-up, recurrence infection time, number of UTIs/patients/year, patient quality of life, subjective symptoms score, and treatment-emergent side effects were recorded and analyzed. In total, 157 women (mean age: 54.2 ± 4.1 years) were included in the analysis. All patients had at least 12 months follow-up. After 4 weekly and 5 monthly HA-CS bladder instillations, UTI episodes decreased from 4.13 ± 1.14 to 0.44 ± 0.50 (p = 0.01) at 12 months, while recurrent UTI time prolonged from 94.8 ± 25.1 days to 178.4 ± 37.3 days (p = 0.01) at 12 months. An improvement in symptoms and quality of life was achieved. A medium-depth pain after medication instillation was the most reported side effect. Regression model analysis showed significant risk factors in developing new UTI episodes: being more than 50 years old and having more than 4 UTI episodes per year (OR 3.41; CI 95%; 1.51-7.71, p = 0.003 and OR 3.31; CI 95% 1.51-7.22; p = 0.003, respectively). Retrospective design and lack of a control group represent two main limitations of the study. Restoring glycosaminoglycans bladder layer therapy is a promising non-antibiotic therapy to prevent recurrent UTIs.

Randomised, double-blind, placebo-controlled studies on flurbiprofen 8.75 mg lozenges in patients with/without group A or C streptococcal throat infection, with an assessment of clinicians' prediction of 'strep throat'.

Diagnosing group A streptococcus (Strep A) throat infection by clinical examination is difficult, and misdiagnosis may lead to inappropriate antibiotic use. Most patients with sore throat seek symptom relief rather than antibiotics, therefore, therapies that relieve symptoms should be recommended to patients. We report two clinical trials on the efficacy and safety of flurbiprofen 8.75 mg lozenge in patients with and without streptococcal sore throat. The studies enrolled adults with moderate-to-severe throat symptoms (sore throat pain, difficulty swallowing and swollen throat) and a diagnosis of pharyngitis. The practitioner assessed the likelihood of Strep A infection based on historical and clinical findings. Patients were randomised to flurbiprofen 8.75 mg or placebo lozenges under double-blind conditions and reported the three throat symptoms at baseline and at regular intervals over 24 h. A total of 402 patients received study medication (n = 203 flurbiprofen, n = 199 placebo). Throat culture identified Strep A in 10.0% of patients and group C streptococcus (Strep C) in a further 14.0%. The practitioners' assessments correctly diagnosed Strep A in 11/40 cases (sensitivity 27.5%, and specificity 79.7%). A single flurbiprofen lozenge provided significantly greater relief than placebo for all three throat symptoms, lasting 3-4 h for patients with and without Strep A/C. Multiple doses of flurbiprofen lozenges over 24 h also led to symptom relief, although not statistically significant in the Strep A/C group. There were no serious adverse events. The results highlight the challenge of identifying Strep A based on clinical features. With the growing problem of antibiotic resistance, non-antibiotic treatments should be considered. As demonstrated here, flurbiprofen 8.75 mg lozenges are an effective therapeutic option, providing immediate and long-lasting symptom relief in patients with and without Strep A/C infection.

Effects of different types of N deposition on the fungal decomposition activities of temperate forest soils

Nitrogen (N) deposition significantly affects soil microbial activities and litter decomposition processes in forest ecosystems. However, the changes in soil fungi during litter decomposition remain unclear. In this study, ammonium nitrate was selected as inorganic N (IN), whereas urea and glycine were selected as organic N (ON). N fertilizer with different IN-to-ON ratios (1:4, 2:3, 3:2, 4:1, and 5:0) was mixed in equal amounts and then added to temperate forest soils. Half of each treatment was simultaneously added with streptomycin to inhibit soil bacteria. The activities of enzymes involved in litter decomposition (invertase, β-glucosidase, cellulase, polyphenol oxidase, and phosphatase) were assayed after a three-year field experiment. The results showed that enzymatic activities were inhibited by IN addition but accelerated by ON addition in the non-antibiotic addition treatments. An increase in ON in the mixed N fertilizer also shifted enzymatic activities from N inhibition to N stimulation. Similarly, in the antibiotic addition treatments, fungal activities revealed the same trends, but they were seriously inhibited by IN and significantly accelerated by ON. These results indicated that soil fungi were more sensitive to N deposition, particularly to ON. A large amount of ON may convert soil microbial communities into a fungi-dominated system. However, excessive ON deposition (20% IN+80% ON) caused N saturation and repressed fungal activities. These results suggested that soil fungi were sensitive to N type and that different IN-to-ON ratios may induce diverse ecological effects on soil fungi.

Short communication: An in vitro assessment of the antibacterial activity of plant-derived oils

Nonantibiotic treatments for mastitis are needed in organic dairy herds. Plant-derived oils may be useful but efficacy and potential mechanisms of action of such oils in mastitis therapy have not been well documented. The objective of the current study was to evaluate the antibacterial activity of the plant-derived oil components of Phyto-Mast (Bovinity Health LLC, Narvon, PA), an herbal intramammary product, against 3 mastitis-causing pathogens: Staphylococcus aureus, Staphylococcus chromogenes, and Streptococcus uberis. Plant-derived oils evaluated were Thymus vulgaris (thyme), Gaultheria procumbens (wintergreen), Glycyrrhiza uralensis (Chinese licorice), Angelica sinensis, and Angelica dahurica. Broth dilution testing according to standard protocol was performed using ultrapasteurized whole milk instead of broth. Controls included milk only (negative control), milk + bacteria (positive control), and milk + bacteria + penicillin-streptomycin (antibiotic control, at 1 and 5% concentrations). Essential oil of thyme was tested by itself and not in combination with other oils because of its known antibacterial activity. The other plant-derived oils were tested alone and in combination for a total of 15 treatments, each replicated 3 times and tested at 0.5, 1, 2, and 4% to simulate concentrations potentially achievable in the milk within the pre-dry-off udder quarter. Thyme oil at concentrations ≥2% completely inhibited bacterial growth in all replications. Other plant-derived oils tested alone or in various combinations were not consistently antibacterial and did not show typical dose-response effects. Only thyme essential oil had consistent antibacterial activity against the 3 mastitis-causing organisms tested in vitro. Further evaluation of physiological effects of thyme oil in various preparations on mammary tissue is recommended to determine potential suitability for mastitis therapy.

Photodynamic antibacterial and antibiofilm activity of RLP068/Cl against Staphylococcus aureus and Pseudomonas aeruginosa forming biofilms on prosthetic material

Prosthetic joint infections (PJIs) are becoming a growing public health concern in developed countries as more people undergo arthroplasty for bone fixation or joint replacement. Because a wide range of bacterial strains responsible for PJIs can produce biofilms on prosthetic implants and because the biofilm structure confers elevated bacterial resistance to antibiotic therapy, new drugs and therapies are needed to improve the clinical outcome of treatment of PJIs. Antimicrobial photodynamic therapy (APDT), a non-antibiotic broad-spectrum antimicrobial treatment, is also active against multidrug-resistant micro-organisms such as meticillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa. APDT uses a photosensitiser that targets bacterial cells following exposure to visible light. APDT with RLP068/Cl, a novel photosensitiser, was studied by confocal laser scanning microscopy (CLSM) to evaluate the disruption of MRSA and P. aeruginosa biofilms on prosthetic material. Quantitative CLSM studies showed a reduction in biofilm biomass (biofilm disruption) and a decrease in viable cell numbers, as determined by standard plate counting, in the S. aureus and P. aeruginosa biofilms exposed to APDT with the photosensitiser RLP068/Cl. APDT with RLP068/Cl may be a useful approach to the treatment of PJI-associated biofilms.

A More Clinically Relevant Model of Ventilator-associated Pneumonia?

A More Clinically Relevant Model of Ventilator-associated Pneumonia?

English

Bacterial vaginosis (BV) is a vaginal infection that occurs when the balance of bacteria in the vagina is altered. It is a common condition affecting millions of women. Although the syndrome is curable with standard drugs such as metronidazole and clindamycin, relapse rates are high. Many patients are asymptomatic and recurrence is difficult to differentiate from treatment failure. The infection can have gynaecological and obstetric complications. In addition, there is an association with the transmission of sexually transmitted infections (STIs) including HIV/AIDS. This review focuses on the epidemiology, aetiology, diagnosis, complications and treatment of BV, with emphasis on the role of non-antimicrobial treatment options. Firstly, the lowering of the vaginal pH is discussed as one possible treatment option. An overview is given of the use of acetic and lactic acid gels, boric acid suppositories, as well as studies that reported on the use of douches and tampons. Thereafter, the role of Lactobacillus (probiotic) supplementation as treatment is discussed. Literature sources recommend that more research on BV be conducted. Although standard pharmacological therapy is effective, there are limited treatment options available. Recent research indicating the presence of a structured polymicrobial Gardnerella vaginalis biofilm attached to the endometrium may have major implications for future research into the pathogenesis and treatment of BV. Key words: Bacterial vaginosis (BV), vaginal pH, acidic vaginal gel, Lactobacilli, Gardnerella vaginalis, anaerobes, non-antibiotic treatment.

Bile Salt Inhibition of Host Cell Damage by Clostridium Difficile Toxins

Virulent Clostridium difficile strains produce toxin A and/or toxin B that are the etiological agents of diarrhea and pseudomembranous colitis. Treatment of C. difficile infections (CDI) has been hampered by resistance to multiple antibiotics, sporulation, emergence of strains with increased virulence, recurrence of the infection, and the lack of drugs that preserve or restore the colonic bacterial flora. As a result, there is new interest in non-antibiotic CDI treatments. The human conjugated bile salt taurocholate was previously shown in our laboratory to inhibit C. difficile toxin A and B activities in an in vitro assay. Here we demonstrate for the first time in an ex vivo assay that taurocholate can protect Caco-2 colonic epithelial cells from the damaging effects of the C. difficile toxins. Using caspase-3 and lactate dehydrogenase assays, we have demonstrated that taurocholate reduced the extent of toxin B-induced apoptosis and cell membrane damage. Confluent Caco-2 cells cultured with toxin B induced elevated caspase-3 activity. Remarkably, addition of 5 mM taurocholate reduced caspase-3 activity in cells treated with 2, 4, 6, and 12 µg/ml of toxin B by 99%, 78%, 64%, and 60%, respectively. Furthermore, spent culture medium from Caco-2 cells incubated with both toxin B and taurocholate exhibited significantly decreased lactate dehydrogenase activity compared to spent culture medium from cells incubated with toxin B only. Our results suggest that the mechanism of taurocholate-mediated inhibition functions at the level of toxin activity since taurocholate did not affect C. difficile growth and toxin production. These findings open up a new avenue for the development of non-antibiotic therapeutics for CDI treatment.

Use of behavioral economics and social psychology to improve treatment of acute respiratory infections (BEARI): rationale and design of a cluster randomized controlled trial [1RC4AG039115-01] - study protocol and baseline practice and provider characteristics

BackgroundInappropriate antibiotic prescribing for nonbacterial infections leads to increases in the costs of care, antibiotic resistance among bacteria, and adverse drug events. Acute respiratory infections (ARIs) are the most common reason for inappropriate antibiotic use. Most prior efforts to decrease inappropriate antibiotic prescribing for ARIs (e.g., educational or informational interventions) have relied on the implicit assumption that clinicians inappropriately prescribe antibiotics because they are unaware of guideline recommendations for ARIs. If lack of guideline awareness is not the reason for inappropriate prescribing, educational interventions may have limited impact on prescribing rates. Instead, interventions that apply social psychological and behavioral economic principles may be more effective in deterring inappropriate antibiotic prescribing for ARIs by well-informed clinicians.Methods/designThe Application of Behavioral Economics to Improve the Treatment of Acute Respiratory Infections (BEARI) Trial is a multisite, cluster-randomized controlled trial with practice as the unit of randomization. The primary aim is to test the ability of three interventions based on behavioral economic principles to reduce the rate of inappropriate antibiotic prescribing for ARIs. We randomized practices in a 2 × 2 × 2 factorial design to receive up to three interventions for non-antibiotic-appropriate diagnoses: 1) Accountable Justifications: When prescribing an antibiotic for an ARI, clinicians are prompted to record an explicit justification that appears in the patient electronic health record; 2) Suggested Alternatives: Through computerized clinical decision support, clinicians prescribing an antibiotic for an ARI receive a list of non-antibiotic treatment choices (including prescription options) prior to completing the antibiotic prescription; and 3) Peer Comparison: Each provider’s rate of inappropriate antibiotic prescribing relative to top-performing peers is reported back to the provider periodically by email. We enrolled 269 clinicians (practicing attending physicians or advanced practice nurses) in 49 participating clinic sites and collected baseline data. The primary outcome is the antibiotic prescribing rate for office visits with non-antibiotic-appropriate ARI diagnoses. Secondary outcomes will examine antibiotic prescribing more broadly. The 18-month intervention period will be followed by a one year follow-up period to measure persistence of effects after interventions cease.DiscussionThe ongoing BEARI Trial will evaluate the effectiveness of behavioral economic strategies in reducing inappropriate prescribing of antibiotics.Trials registrationClinicalTrials.gov: NCT01454947

Effect of sub-lethal photodynamic inactivation on the antibiotic susceptibility and biofilm formation of clinical Staphylococcus aureus isolates

A promising approach to kill antibiotic-resistant bacteria uses light in combination with a photosensitizer to induce a phototoxic reaction. A major concern with the use of any non-antibiotic antimicrobial treatment is that exposure of bacteria to sub-lethal concentrations will lead to the development of resistance to antibiotics. This study aimed to determine the effect of sub-lethal photodynamic inactivation (PDI) on the antibiotic susceptibility and biofilm formation of clinical Staphylococcus aureus isolates. Forty clinical S. aureus isolates were exposed to PDI with toluidine blue O (TBO) and methylene blue (MB). After exposure, susceptibility of surviving organisms to a range of antibiotics was determined and compared with the susceptibility of an untreated control. PDI experiments were done during three generations for assessment of biofilm formation, to determine if biofilm formation was affected by exposure to PDI. It was observed that the effect of sub-lethal PDI on the antibiotic sensitivity was strain-dependent. In general, exposure to sub-lethal MB/TBO-PDI increased resistance to erythromycin, amoxicillin-clavulanate and amikacin. Biofilm formation ability of studied clinical isolates increased after second sub-lethal PDI regimen compared to that before PDI. S. aureus cells may develop resistance by growing in the presence of sub-lethal MB/TBO-PDI.

Photodynamic therapy of antibiotic-resistant biofilms in a maxillary sinus model.

Chronic rhinosinusitis (CRS) is one of the most common chronic conditions in the United States. There is a significant subpopulation of CRS patients who remain resistant to cure despite rigorous treatment regimens including surgery, allergy therapy, and prolonged antibiotic therapy. Antimicrobial photodynamic therapy (aPDT) is a noninvasive nonantibiotic broad spectrum antimicrobial treatment. Our previous in vitro studies demonstrated that aPDT reduced CRS polymicrobial planktonic bacteria and fungi by >99.9% after a single treatment. However, prior to human treatment, the effectiveness of aPDT to eradicate polymicrobial biofilms in a maxillary sinus cavity must be demonstrated. The objective of this study was to demonstrate the effectiveness of a noninvasive aPDT treatment of antibiotic resistant biofilms known to cause CRS in a novel anatomically correct maxillary sinus in vitro model using an enhanced photosensitizer solution. Antibiotic resistant polymicrobial biofilms of Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus (MRSA) were grown in an anatomically correct novel maxillary sinus model and treated with a methylene blue/ethylenediamine tetraacetic acid (EDTA) photosensitizer and 670-nm nonthermal activating light. Cultures of the biofilms were obtained before and after light treatment to determine efficacy of biofilm reduction. The in vitro maxillary sinus CRS biofilm study demonstrated that aPDT reduced the CRS polymicrobial biofilm by >99.99% after a single treatment. aPDT can effectively treat CRS polymicrobial antibiotic resistant Pseudomonas aeruginosa and MRSA biofilms in a maxillary sinus cavity model.

The effect of antimicrobial photodynamic therapy on human ciliated respiratory mucosa

Chronic recurrent sinusitis (CRS) is one of the most common chronic conditions in the United States. There is a significant subpopulation of CRS patients who remain resistant to cure despite rigorous treatment regimens including surgery, allergy therapy, and prolonged antibiotic therapy. Antimicrobial photodynamic therapy (aPDT) is a noninvasive nonantibiotic broad spectrum antimicrobial treatment. Our previous in vitro studies demonstrated that aPDT reduced CRS polymicrobial biofilm and planktonic bacteria and fungi by > 99.9% after a single treatment. Prior to human treatment however, aPDT treatment must be demonstrated to not result in histologic damage to the sinus ciliated respiratory epithelium. The objective of this study was to demonstrate the safety of aPDT treatment on a living human ciliated respiratory mucosal model (EpiAirway). A study of aPDT treatment of EpiAirway was performed. Treatment groups included a nontreatment control, laser light alone, photosensitizer alone, and therapeutic photosensitizer and light combination (aPDT). At completion of treatment, the EpiAirway tissue was fixed in 10% formalin, paraffin-embedded, sectioned, H&E stained and mounted. All samples were blinded and microscopically examined by a human pathologist to assess any effect of aPDT on the tissue, cilia, or mucosal glands. The results were correlated with the treatment parameters. The EpiAirway histologic study demonstrated no histologic alteration of the respiratory cilia or mucosal epithelium in any of the treatment groups. aPDT is a safe treatment for CRS resulting in no histologic alteration of human ciliated respiratory mucosa as is found in the human sinuses.

Abundance and Distribution of Tetracycline Resistance Genes and Mobile Elements in an Oxytetracycline Production Wastewater Treatment System

We investigated the abundance and distribution of tetracycline resistance genes (tet genes) in an oxytetracycline (OTC) antibiotic production wastewater (APW) treatment system. Of sixteen tet genes and five mobile elements, nine tet genes (tet(A), tet(C), tet(G), tet(L), tet(M), tet(O), tet(Q), tet(W), and tet(X)) and two mobile elements (class 1 integron (intI1) and transposon Tn916/1545) were successfully quantified by real-time PCR. The relative abundance of tet genes in the effluent and activated sludge (1.2 × 10(-4) to 1.3 × 10(0)) of the APW treatment system were up to 2 orders of magnitude higher than those in the OTC fermentation residues (8.5 × 10(-5) to 6.7 × 10(-3)) (P < 0.01), and 1-4 orders of magnitude higher than those in sewage and nonantibiotic production wastewater treatment systems (P < 0.01), showing that the discharge of abundant tet genes from the APW treatment system is worthy of attention. The three most abundant genes in the APW treatment system, tet(A), tet(C), and tet(G), exhibited significant positive correlations with intI1 (R(2) = 0.73, 0.95, and 0.83, respectively; P < 0.05), suggesting that intI1 may be involved in their proliferation. This is the first study showing that some measures may be required to control the discharge of antibiotic resistance genes from treated APW and activated sludge.

In This Issue: From Communities of Solution to Joy

This issue features a bold proposal for community-focused approaches to improving health. While the approaches are new, they build on a blueprint from more than 40 years ago. In addition, a cluster of articles present new knowledge for the care of diverse groups of vulnerable people. Another clinical research article summarizes scientific evidence for a limited nonantibiotic treatment for sinusitis. A novel proposal and an editorial consider paying patients for “performance” reaching measurable health goals, while a study of a large scheme for paying practices for performance is shown to have no effect on reducing ethnic disparities in management of diabetes. A study of the effect of electronic health records on diabetes care improvement, a useful methodological reference for practice-based research, and an essay that reveals a path toward the joy of family medicine, round out the issue.