Benefits of sea buckthorn (Hippophae rhamnoides) pulp oil-based mouthwash on oral health.

AIM: The purpose of this study was to conduct phytochemical analysis of sea buckthorn pulp oil and to evaluate the antimicrobial, anti-biofilm and antioxidant activities of its mouthwash form. METHODS AND RESULTS: Fatty acid composition of the sea buckthorn pulp oil was determined by GC-MS analysis, which revealed that, mono-unsaturated fatty acid, palmitoleic acid and saturated fatty acid, palmitic acid, were the major constituents. The antimicrobial and the anti-biofilm capacities of sea buckthorn pulp oil mouthwash form were evaluated against Streptococcus gordonii, Porphyromonas gingivalis, Actinomyces viscosus and Candida albicans, according to the European Norms, and the Biofilm Ring Test® , respectively. These activities were then compared with those of chlorhexidine and herbal mouthwashes. The sea buckthorn-based mouthwash was bactericidal against S. gordonii and P. gingivalis, bacteriostatic against A. viscosus and showed no antifungal effect. Regardless of the strains used, complete inhibition of biofilm formation was achieved. The antioxidant activity of this experimental mouthwash was also assessed by DPPH and NBT assays. CONCLUSION: Sea buckthorn mouthwash showed anti-biofilm activities against select single and multiple oral bacterial species. SIGNIFICANCE AND IMPACT OF THE STUDY: In this study, a mouthwash derived from sea buckthorn (Hippophae rhamnoides) pulp oil has been experimented, for the first time, in order to overcome the problem of a large number of available synthetic mouthwashes which have side effects on teeth, gums and mucous membranes. This mouthwash seemed to be a suitable alternative for a preventive agent for periodontal inflammation.

Antibiotic content of selective culture media for isolation of Capnocytophaga species from oral polymicrobial samples.

UNLABELLED: In oral microbiome, because of the abundance of commensal competitive flora, selective media with antibiotics are necessary for the recovery of fastidious Capnocytophaga species. The performances of six culture media (blood agar, chocolate blood agar, VCAT medium, CAPE medium, bacitracin chocolate blood agar and VK medium) were compared with literature data concerning five other media (FAA, LB, TSBV, CapR and TBBP media). To understand variable growth on selective media, the MICs of each antimicrobial agent contained in this different media (colistin, kanamycin, trimethoprim, trimethoprim-sulfamethoxazole, vancomycin, aztreonam and bacitracin) were determined for all Capnocytophaga species. Overall, VCAT medium (Columbia, 10% cooked horse blood, polyvitaminic supplement, 3·75 mg l(-1) of colistin, 1·5 mg l(-1) of trimethoprim, 1 mg l(-1) of vancomycin and 0·5 mg l(-1) of amphotericin B, Oxoid, France) was the more efficient selective medium, with regard to the detection of Capnocytophaga species from oral samples (P < 0·001) and the elimination of commensal clinical species (P < 0·001). The demonstrated superiority of VCAT medium, related to its antibiotic content, made its use indispensable for the optimal isolation of Capnocytophaga species from polymicrobial samples. SIGNIFICANCE AND IMPACT OF THE STUDY: Isolation of Capnocytophaga species is important for the proper diagnosis and treatment of the systemic infections they cause and for epidemiological studies of periodontal flora. We showed that in pure culture, a simple blood agar allowed the growth of all Capnocytophaga species. Nonetheless, in oral samples, because of the abundance of commensal competitive flora, selective media with antibiotics are necessary for the recovery of Capnocytophaga species. The demonstrated superiority of VCAT medium made its use essential for the optimal detection of this bacterial genus. This work showed that extreme caution should be exercised when reporting the isolation of Capnocytophaga species from oral polymicrobial samples, because the culture medium is a determining factor.

CASA chromogenic medium for enteric Campylobacter species.

We prospectively assessed stool samples from 370 patients for Campylobacter species by comparing three selective agar media incubated at two temperatures: 42°C and 37°C. Twenty patients (5.4%) were found positive. The chromogenic medium CASA (AES Chemunex, France) proved highly efficient for C. jejuni and C. coli recovery, while lessening the workload in the lab.

Inbreeding reveals stronger net selection on Drosophila melanogaster males: implications for mutation load and the fitness of sexual females.

Stronger selection on males has the potential to lower the deleterious mutation load of females, reducing the cost of sex. However, few studies have directly quantified the strength of selection for both sexes. As the magnitude of inbreeding depression (ID) is related to the strength of selection, we measured the cost of inbreeding for both males and females in a laboratory population of Drosophila melanogaster. Using a novel technique for inbreeding, we found significant ID for both juvenile viability and adult fitness in both sexes. The genetic variation responsible for this depression in fitness appeared to be recessive for adult fitness (h=0.11) and partially additive for juvenile viability (h=0.29). ID was identical across the sexes in terms of juvenile viability but was significantly more deleterious for males than females as adults, even though female X-chromosome homogamety should predispose them to a higher inbreeding load. We estimated the strength of selection on adult males to be 1.24 greater than on adult females, and this appears to be a consequence of selection arising from competition for mates. Combined with the generally positive intersexual genetic correlation for inbred lines, our results suggest that the mutation load of sexual females could be meaningfully reduced by stronger selection acting on males.

Staphylococcus simulans as an authentic pathogenic agent of osteoarticular infections.

OBJECTIVES: To evaluate the role of Staphylococcus simulans in bone and joint infections (BJI) and determine their main characteristics. METHODS: A search of the database of the microbiology laboratories of Lille hospital and Tourcoing hospital was performed. Only results from blood, bone, and orthopedic device cultures were taken into account for hospitalized patients between January 2004 and January 2009. We considered cases in which S. simulans was the only bacteria isolated in all of the patients' biological samples with clinical and laboratory signs of infection. For patients with complete medical records, we recorded the clinical and epidemiological data. RESULTS: Six cases of BJI due to S. simulans were recorded, with five cases related to orthopedic devices infections. Three patients lived in rural areas. In four out of six patients, S. simulans was isolated in intraoperative biopsy material. In one patient, S. simulans grew in synovial fluid and in another in blood cultures only. The latter patient had a spondylodiscitis, and chronic foot ulcers due to gout disease were suspected to be the origin of the infection. All patients were healed after a mean follow up of 9 ± 3 months. Orthopedic devices were removed in four of the five patients concerned. The combination of rifampicin plus levofloxacin was used in four patients. CONCLUSION: The present data suggest that, even though S. simulans remains rarely observed in clinical pathology, its role in osteoarticular infections, especially in the case of infected orthopedic devices, is not exceptional. As for the antibiotic treatment, the combination of rifampicin and levofloxacin seems to be an effective strategy according to our clinical results.

[Bacteremia of oral origin]. / Bactériémies d'origine buccale.

Transient bacteremia from oral cavity related to oral anaerobic bacteria may occur as a result of dental healthcare procedures but also as a result of daily gestures involving the gums (chewing and oral hygiene). The risk of presenting a transient bacteremia is related to oral cavity bacterial load and to the severity of inflammation in the oral cavity. Although bacteremia is transient, in patients with immunodeficiency or comorbidity, this bacteremia may cause extra-oral infections. The bacteremia rate and the identified bacteria vary from one study to the next, depending on the method used to isolate and identify bacteria. Nevertheless, the risk for bacteremia is determined by the infectious and inflammatory conditions of each patient.

Mortality in out-of-hours emergency medical admissions--more than just a weekend effect.

Mortality among emergency medical admissions to hospital is higher for admissions at the weekend than on weekdays; this also holds true for certain specific conditions. However, it is unknown whether that effect is limited to weekends. This study calculated mortality in emergency medical admissions for each day of the week, and compared mortality at weekends with weekdays, at nights with days, and in all out-of-hours periods with in-hours in a UK district general hospital. Total mortality was increased for admissions on Mondays, at night, and in all out-of-hours periods; late in-hospital mortality (after seven days) remained increased when the initial admission occurred on Mondays, at night or out of hours. It is likely that illness severity as well as resource and organisational factors are involved.

fimA genotypes and PFGE profile patterns in Porphyromonas gingivalis isolates from subjects with periodontitis.

BACKGROUND AND OBJECTIVES: Porphyromonas gingivalis is frequently identified to type by evaluation of fimA polymorphisms and less often by pulsed-field gel electrophoresis (PFGE) because of the technical intricacies of PFGE. To compare these techniques, we genotyped P. gingivalis clinical isolates as to (i) their fimA type and (ii) their whole genome restriction profile (PFGE analysis). MATERIAL AND METHODS: Thirty-two P. gingivalis strains were isolated from 16 unrelated periodontitis patients. Two strains were isolated from each patient. Strains were subjected to a fimA-typing polymerase chain reaction (PCR) assay. Strains that could not be typed by PCR were submitted to sequencing of the entire fimA gene. The PFGE profiles of clinical strains were compared using bioinformatic analysis. RESULTS: Seven of the 32 isolates were not typeable by PCR and so their entire fimA gene was sequenced. The sequencing identified each strain as belonging to a single fimA type. In one case, sequencing of the fimA gene did not agree with the result obtained using fimA PCR typing. With the exception of one patient, each patient presented isolates bearing the same fimA type. However, in three patients, isolates with the same fimA type presented different PFGE pulsotypes. CONCLUSION: The P. gingivalis typing using fimA PCR has limitations in typeability and discriminatory power. A typing technique for P. gingivalis that is easy to perform but that presents adequate typeability and discriminatory power is needed if we want to better understand the epidemiology of periodontal disease.

Interactions between oral commensal Candida and oral bacterial communities in immunocompromised and healthy children.

Candida species are usually found as commensal microorganisms in the oral cavity of healthy people. During chemotherapy, cytostatic drugs lead to depletion of the oral flora with the emergence of a dominant bacterial species. The transition from commensal to pathogenic state, further associated with yeast colonization and oral mucositis implies a replacement of the dominant microorganism by Candida albicans. This process goes plausibly through cooperation between C. albicans and bacteria. This study focused on the first step of cooperation between microorganisms isolated from the same oral flora either of leukemic or healthy children. C. albicans isolated from 8/20 children were cultured to display their noninvasive blastosporic yeast form and mixed with their dominant bacteria to study the capacity of planktonic aggregation and the early state of biofilm formation. None of the dominant bacteria opposed the presence of yeast, on the contrary, an interesting cooperation was observed. This behavior is apparently different from that observed when mixing the type strains. In fact, three mutated C. albicans strains display, by their spontaneous ability to form filament, enhanced risks of virulence for leukemic ill carriers. Despite such risks, neither oral nor systemic pathology were observed in ill patients probably because the study was conducted during the first course of chemotherapy and Candida colonization is related to the number of chemotherapeutic cycles. The presence of C. albicans during the initial cycle represents, by its ability to interact with oral bacteria, an actual threat for further cures.

Expression patterns of genes induced by oxidative stress in Porphyromonas gingivalis.

INTRODUCTION: Porphyromonas gingivalis, a gram-negative anaerobic bacterium, is a major periopathogen whose transmission from host to host involves exposure to atmospheric oxygen. P. gingivalis contains genetic factors that function in an oxidative stress response, but their expression has not been analyzed during exposure to atmospheric oxygen. The aim of this study was to obtain a better understanding of atmospheric adaptation of P. gingivalis. METHODS: The aerotolerance of wild-type and oxyR mutant P. gingivalis strains were determined, and quantitative polymerase chain reaction was performed to analyze gene expression patterns in response to exposure to atmospheric oxygen. The analyzed P. gingivalis genes encoded proteins involved in oxidative response (oxyR, ahpC-F, batA, dps, ftn, tpx) as well as several major virulence factors (hagA, hagB, hagE, rgpA, rgpB, hem). RESULTS: Our results demonstrated a critical role for the oxyR gene in the aerotolerance of P. gingivalis. The ahpC-F, batA, and hem genes were slightly overexpressed (between 1.65-fold and 2-fold) after exposure to atmospheric oxygen compared to anaerobic conditions. The level of transcription of dps, ftn, tpx, and rgpA genes increased more than 2.5-fold, and the expression of ahpC-F, dps, ftn, and tpx was partially or completely OxyR-dependent. CONCLUSION: A different transcription pattern of P. gingivalis genes was observed, depending on the stimulus of oxidative stress. We present new evidence that the expression of tpx, encoding a thiol peroxidase, is partially OxyR-dependent and is induced after atmospheric oxygen exposure.

Treponema, Iron and Neurodegeneration.

Spirochetes are suspected to be linked to the genesis of neurological diseases, including neurosyphillis or neurodegeneration (ND). Impaired iron homeostasis has been implicated in loss of function in several enzymes requiring iron as a cofactor, formation of toxic oxidative species, inflammation and elevated production of beta-amyloid proteins. This review proposes to discuss the link that may exist between the involvement of Treponema spp. in the genesis or worsening of ND, and iron dyshomeostasis. Proteins secreted by Treponema can act directly on iron metabolism, with hemin binding ability (HbpA and HbpB) and iron reductase able to reduce the central ferric iron of hemin, iron-containing proteins (rubredoxin, neelaredoxin, desulfoferrodoxin metalloproteins, bacterioferritins etc). Treponema can also interact with cellular compounds, especially plasma proteins involved in iron metabolism, contributing to the virulence of the syphilis spirochetes (e.g. treponemal motility and survival). Fibronectin, transferrin and lactoferrin were also shown to be receptors for treponemal adherence to host cells and extracellular matrix. Association between Treponema and iron binding proteins results in iron accumulation and sequestration by Treponema from host macromolecules during systemic and mucosal infections.

Virulence of viable but nonculturable S. Typhimurium LT2 after peracetic acid treatment.

S. Typhimurium LT2 cells suspended in sterilized sewage effluent water (SEW) and in distilled water microcosms were exposed to 0, 7, 15 and 20 mg/l peracetic acid, and tested for viability and virulence. After treatment for one hour, colony forming units decreased by at least 5 log units at peracetic acid concentration of 7 mg/l. In SEW, at peracetic acid concentration of 15 mg/l, the cells were nonculturable (VNC), but retained virulence as demonstrated by invasion assays of HeLa cells. Higher concentrations (greater than or equal to 20 mg/l) resulted in bacterial death, i.e. substrate non-responsive cells. Despite morphological alterations of the bacteria after peracetic acid treatment, visualized by transmission electronic microscopy, conservation of both adhesive and invasive capacities was confirmed by scanning electron microscopy after exposure to 0-15 mg/l peracetic acid. Public health professionals need to recognize that peracetic acid-treated Salmonella is capable of modifying its physiological characteristics, including entering and recovering from the viable but nonculturable state, and may remain virulent after a stay in SEW followed by peracetic acid treatment.

The ambient aerosol characterization during the prescribed bushfire season in Brisbane 2013.

Prescribed burnings are conducted in Queensland each year from August until November aiming to decrease the impact of bushfire hazards and maintain the health of vegetation. This study reports chemical characteristics of the ambient aerosol, with a focus on source apportionment of the organic aerosol (OA) fraction, during the prescribed biomass burning (BB) season in Brisbane 2013. All measurements were conducted within the International Laboratory for Air Quality and Health (ILAQH) located in Brisbane's Central Business District. Chemical composition, degree of ageing and the influence of BB emission on the air quality of central Brisbane were characterized using a compact Time of Flight Aerosol Mass Spectrometer (cToF-AMS). AMS loadings were dominated by OA (64%), followed by, sulfate (17%), ammonium (14%) and nitrates (5%). Source apportionment was applied on the AMS OA mass spectra via the multilinear engine solver (ME-2) implementation within the recently developed Source Finder (SoFi) interface. Six factors were extracted including hydrocarbon-like OA (HOA), cooking-related OA (COA), biomass burning OA (BBOA), low-volatility oxygenated OA (LV-OOA), semivolatile oxygenated OA (SV-OOA), and nitrogen-enriched OA (NOA). The aerosol fraction that was attributed to BB factor was 9%, on average over the sampling period. The high proportion of oxygenated OA (72%), typically representing aged emissions, could possess a fraction of oxygenated species transfored from BB components on their way to the sampling site.

ADP controls the electrogenicity of Na/Na exchange catalyzed by dog kidney Na,K-ATPase proteoliposomes.

Sodium pump mediated Na/Na exchange was studied using Na(+)-loaded proteoliposomes prepared from dog kidney Na,K-ATPase. Measurements of both 22Na+ influx and pump-generated electrical potentials were carried out, the latter using the anionic dye, oxonol VI. In the presence of ATP, the formation of a strophanthidin-sensitive membrane potential confirms that Na/Na exchange associated with ATP hydrolysis can be electrogenic depending on the source of the enzyme. With the addition of varying concentrations of ADP, electrogenic exchange is progressively inhibited and replaced by electroneutral exchange. ADP is equally effective in activating (ATP + ADP)-dependent electroneutral exchange. With sufficient ADP, electrogenic Na/Na exchange is completely replaced by electroneutral exchange.

c-myc amplification coexistent with activating N-ras point mutation in the biphenotypic leukemic cell line RED-3.

While activation of the protooncogene c-N-ras is observed regularly in acute myelogenous leukemia, amplification of c-myc in AML cells or derived lines is uncommon. In particular, concurrent ras/myc activation, which has been shown to be critical in several elegant models of malignancy, has been demonstrated in a very small number of human tumors or derivative cell lines. A cell line, RED-3, is described which was derived from cells of a patient with aggressive acute leukemia which exhibits many markers of lineage infidelity. DNA from this cell line contains an activating point mutation of c-N-ras as well as 20-30-fold amplification of c-myc. After HL-60, this is the second example of ras/myc activation in AML derived cells and demonstrates that this lesion is not unique to HL-60. Rather, it may be important in leukemogenesis in a small proportion of AML patients.

Oral complications during treatment of malignant diseases in childhood: effects of tooth brushing.

During anticancer treatment, oral lesions considerably aggravate the child's clinical condition and increase the risk of infection. This prospective study evaluated the incidence, nature and chronology of oral complications arising during the first 6 weeks of chemotherapy. 131 children were included in this study, and their oral and dental health evaluated on enrolment. Each child was observed once a week, for 6 weeks. Fifty-two per cent (68/131) of the children presented with at least one oral lesion. Two oral healthcare regimens (with or without tooth brushing) were evaluated. Tooth brushing significantly reduced the number of children affected. Standardised multicentre studies should permit the definition of oral care regimens which would eliminate pain and reduce the risk of infection in children hospitalised for cancer.

Evaluation of the in vitro biocompatibility of various elastomers.

A previous study highlighted the superior shock absorption of silicone rubbers compared to other elastomers. We evaluated and compared the in vitro biocompatibility of silicone-based rubbers and propose them as an alternative to conventional products. We used the MTT colorimetric test to assess cell viability and flow cytometry to evaluate cell proliferation. Tests were conducted at 24 and 72 h. Changes in cell morphology were evaluated by scanning electron microscopy. Positive (polyurethane) and negative (polystyrene) toxicity controls were included. The number of viable cells was significantly higher on polystyrene than on polyurethane. A decrease in the total number of cells from 24 to 72 h compared to the negative control was correlated with a lower percentage of S-phase cells. The differences in cell viability noted between the samples and the polystyrene control mainly resulted from an initial lack of adhesion, which was confirmed by scanning electron microscopy. The biocompatibility of the three silicone rubbers was comparable to the best of the three products currently being used. These results, combined with those of the previous study, indicate that silicone rubber could be considered for the manufacture of mouth guards.

In vitro study of the effect of titanium on porphyromonas gingivalis in the presence of metronidazole and spiramycin.

Septic peri-implantitis is the main clinical complication encountered following the insertion of titanium implants. It may be resistant to conventional antibiotic treatments. Reports in the literature about antibiotic behavior in the presence of titanium remain controversial. They vary from a bacteriostat to a decreased effect of antibiotic. This study examined, in vitro, the viability of Porphyromonas gingivalis, frequently associated with periodontal diseases, in the presence of titanium and antibiotics (spiramycin and metronidazole alone or in combination). Viability of P. gingivalis was determined, versus a standard curve using the Live/dead Baclight Bacteria Viability Kit on 96 well microplates. The results of 48 experiments (60 measurements each) were compiled in a database and compared to each other using the chi2p < 0.05 test. When used alone, titanium enhanced bacterial growth as the nickel-chrome control. However, when titanium was used in the presence of antibiotics, antibiotics kept their own effects. Even more, titanium was shown to potentialize the effect of metronidazole. The strengthening of effectiveness of metronidazole by titanium may be due to the oxidation potential of the metal. This chemical property could explain the conflicting data reported in the literature.

Evaluation of the capacity of the SCGE assay to assess the genotoxicity of biomaterials.

The comet test or SCGE assay, which is already widely used in other areas, has never been used to evaluate the mutagenic potential of medical biomaterials in the final form. The purpose of our study was thus to assess the comet test as a means of assessing the genotoxic potential of finished medical biomaterials. We used silicone elastomers with increasing concentrations of 4-nitroquinoline oxide, a genotoxic agent. Hydrogen peroxide was used as the positive control, and tissue culture polystyrene as the negative control. In our study, the comet test did not detect a significant difference in genotoxicity between the pure elastomer and the same elastomer containing 0.01 mg/ml 4-nitroquinoline oxide, but did detect a significant difference between two elastomers containing 0.01 and 0.3 mg/ml of 4-nitroquinoline oxide, respectively. Since, the surface properties of the samples were identical, only the chemical composition may have caused significant differences in mutagenicity. Whatever the cause of the genotoxicity detected by the SCGE assay, testing finished biomaterials using the comet assay makes it possible to evaluate interactions between biomaterials and living tissues that are much closer to actual application conditions.

Pathophysiology of accidental hypothermia.

Accidental hypothermia is an uncommon problem that affects people of all ages, but particularly the elderly. This review briefly outlines the aetiological factors that may predispose to hypothermia, with particular reference to the effects of sepsis, although the specific situation of cold-water immersion is not addressed. A more detailed analysis of the pathophysiology of hypothermia then examines the cardiovascular, haematological, neurological, respiratory, renal, metabolic, and gastrointestinal systems. Clinically relevant findings are highlighted and some associated management points are related to the physiological changes. Most of these changes are reversible on rewarming, and are resistant to pharmacological manipulation; some of the pathological effects are related more to the process of rewarming than to the hypothermia itself.