In vitro SCREENING ANTIBACTERIAL ACTIVITY OF Bidens pilosa LINNÉ AND Annona crassiflora MART. AGAINST OXACILLIN RESISTANT Staphylococcus aureus (ORSA) FROM THE AERIAL ENVIRONMENT AT THE DENTAL CLINIC

Currently multiresistant Staphylococcus aureus is one common cause of infections with high rates of morbidity and mortality worldwide, which directs scientific endeavors in search for novel antimicrobials. In this study, nine extracts from Bidens pilosa (root, stem, flower and leaves) and Annona crassiflora (rind fruit, stem, leaves, seed and pulp) were obtained with ethanol: water (7:3, v/v) and their in vitro antibacterial activity evaluated through both the agar diffusion and broth microdilution methods against 60 Oxacillin Resistant S. aureus (ORSA) strains and against S. aureus ATCC6538. The extracts from B. pilosa and A. crassiflora inhibited the growth of the ORSA isolates in both methods. Leaves of B. pilosa presented mean of the inhibition zone diameters significantly higher than chlorexidine 0.12% against ORSA, and the extracts were more active against S. aureus ATCC (p < 0.05). Parallel, toxicity testing by using MTT method and phytochemical screening were assessed, and three extracts (B. pilosa, root and leaf, and A. crassiflora, seed) did not evidence toxicity. On the other hand, the cytotoxic concentrations (CC50 and CC90) for other extracts ranged from 2.06 to 10.77 mg/mL. The presence of variable alkaloids, flavonoids, tannins and saponins was observed, even though there was a total absence of anthraquinones. Thus, the extracts from the leaves of B. pilosa revealed good anti-ORSA activity and did not exhibit toxicity.

IDENTIFICATION OF Pseudomonas spp. AS AMOEBA-RESISTANT MICROORGANISMS IN ISOLATES OF Acanthamoeba

Acanthamoeba is a “Trojan horse” of the microbial world. The aim of this study was to identify the presence of Pseudomonas as an amoeba-resistant microorganism in 12 isolates of Acanthamoeba. All isolates showed the genus Pseudomonas spp. as amoeba-resistant microorganisms. Thus, one can see that the Acanthamoeba isolates studied are hosts of Pseudomonas.

FACTORS RELATED TO ORAL CANDIDIASIS IN ELDERLY USERS AND NON-USERS OF REMOVABLE DENTAL PROSTHESES

This study examined the association between oral candidiasis in elderly users and nonusers of prosthesis and its predisposing factors. To this end, we performed a cross-sectional study where saliva samples from 48 patients were collected they used prosthesis and 43 patients (control group) who did not use. Among the 91 patients, Candida spp were isolated in 40 (83.3%) who used prosthesis and in 23 (53.5%) in the control group. A statistically significant association was determined between the two groups, the isolation of yeasts and dental prosthesis (p < 0.05, OR = 4.3). The most common etiological agent was Candida albicans (37 isolates), with 23 (62.2%) in the denture group and 14 (37.8%) (control group). Among patients who presented clinical manifestations of oral candidiasis (n = 24), 83.3% (n = 20) belonged to the group that wore dentures, while only 16.7% (n = 4) belonged to the control group. Elderly patients with diabetes had 4.4 times higher estimated risk of developing oral candidiasis when compared with individuals without this condition. There was no statistically significant association between being user prostheses and have diabetes with the onset of candidiasis. No statistically significant association was determined between xerostomia, use of prosthesis and oral candidiasis. The use of prosthetics and poor oral hygiene in elderly patients predisposes to the development of oral candidiasis.

Atividade antimicrobiana, antiaderente e antifúngica in vitro de plantas medicinais brasileiras sobre microrganismos do biofilme dental e cepas do gênero Candida

Avaliou-se in vitro a atividade antimicrobiana, antifúngica e antiaderente da aroeira-do-sertão, malva e goiabeira sobre microrganismos do biofilme dental e candidose oral. Os extratos mostraram-se eficazes, inibindo o crescimento das bactérias do biofilme dental e fungos da candidose oral, sugerindo a utilização dessas plantas como meio alternativo na terapêutica odontológica.

Dental and facial characteristics of patients with juvenile idiopathic arthritis

OBJECTIVE: It has been shown that the temporomandibular joint is frequently affected by juvenile idiopathic arthritis, and this degenerative disease, which may occur during facial growth, results in severe mandibular dysfunction. However, there are no studies that correlate oral health (tooth decay and gingival diseases) and temporomandibular joint dysfunction in patients with juvenile idiopathic arthritis. The aim of this study is to evaluate the oral and facial characteristics of the patients with juvenile idiopathic arthritis treated in a large teaching hospital. METHOD: Thirty-six patients with juvenile idiopathic arthritis (26 female and 10 male) underwent a systematic clinical evaluation of their dental, oral, and facial structures (DMFT index, plaque and gingival bleeding index, dental relationship, facial profile, and Helkimo's index). The control group was composed of 13 healthy children. RESULTS: The mean age of the patients with juvenile idiopathic arthritis was 10.8 years; convex facial profile was present in 12 juvenile idiopathic arthritis patients, and class II molar relation was present in 12 (P = .032). The indexes of plaque and gingival bleeding were significant in juvenile idiopathic arthritis patients with a higher number of superior limbs joints involved (P = .055). Anterior open bite (5) and temporomandibular joint noise (8) were present in the juvenile idiopathic arthritis group. Of the group in this sample, 94% (P = .017) had temporomandibular joint dysfunction, 80% had decreased mandibular opening (P = 0.0002), and mandibular mobility was severely impaired in 33% (P = .015). CONCLUSION: This study confirms that patients with juvenile idiopathic arthritis a) have a high incidence of mandibular dysfunction that can be attributed to the direct effect of the disease in the temporomandibular joint and b) have a higher incidence of gingival disease that can be considered a secondary effect of juvenile idiopathic arthritis on oral health.

Color change using HSB color system of dental resin composites immersed in different common Amazon region beverages

The purpose of this study is to evaluate in vitro the color stability of composite resins when exposed to beverages with high coloring contents from the Amazon region. 240 samples from four different composite brands (Natural Look, Z350, 4Seasons and Opallis) of hue A3 were fabricated using an acrylic matrix. The samples were stored in distilled water at 37ºC for 24 hours. The initial color (T0) was registered using a Canon EOS Rebel XTi 10 mp camera, and then the samples were divided into four groups (n=15): G1 (coffee), G2 (açaí juice), G3 (energetic guaraná) and G4 (control - distilled water). The samples were exposed to solutions of DES (6hs) and RE (18hs) and placed in a double boiler under constant agitation, at 37ºC for 30 days. The samples were immersed in the coloring solutions for 15 minutes daily. After 7, 15 and 30 days, new photographic registers were made (T1, T2 and T3). The images were analyzed using Corel PHOTO-PAINT 12 software to identify the colors through the HSB system. The Kruskal-Wallis and t tests (p<0.05) demonstrated significant differences in color (hue, saturation and brightness). The results revealed that none of the tested composites showed color stability when exposed to coloring solutions, and that the Amazon region beverages (açaí juice and energetic guaraná) showed to be less coloring than coffee.

Antimicrobial activity of honeys from two stingless honeybee species and Apis mellifera (Hymenoptera: Apidae) against pathogenic microorganisms

Honeys are described possessing different properties including antimicrobial. Many studies have presented this activity of honeys produced by Apis mellifera bees, however studies including activities of stingless bees honeys are scarce. The aim of this study was to compare the antimicrobial activity of honeys collected in the Amazonas State from Melipona compressipes, Melipona seminigra and Apis mellifera against Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Chromobacterium violaceum, and Candida albicans. Minimum inhibitory concentrations were determined using the agar dilution method with Müller-Hinton agar (for bacteria) or Saboraud agar (for yeast). Staphylococcus aureus and E. faecalis were inhibited by all honeys at concentrations below 12%, while E. coli and C. violaceum were inhibited by stingless bee honeys at concentrations between 10 and 20%. A. mellifera honey inhibited E. coli at a concentration of 7% and Candida violaceum at 0.7%. C. albicans were inhibited only with honey concentrations between 30 and 40%. All examined honey had antimicrobial activity against the tested pathogens, thus serving as potential antimicrobial agents for several therapeutic approaches.

Infection by microorganisms on soybean seeds obtained from plants treated with growth regulators

This research, deals with the effects of exogenous growth regulators on infection by microorganisms on soybean (Glycine max cv. Davis) seeds. To study the influence of the chemicals, soybean plants were sprayed with gibberellic acid (GA) 100 ppm, (2-chloroethyl) trimethylammonium chloride (CCC) 2,000 ppm, succinic acid-2,2-dimethy1hydrazide (SADH) 4,000 ppm, indolylacetic acid (IAA) 100 ppm, 2,3,5-triiodobenzoic acid (TIBA) 20 ppm (three applications), and Agrostemin (1g/10 ml/ 3 1). Application of growth regulators did not affect infect ion by microorganisms on soybean seeds. The prominent fungus isolated was Phomopsis sojae. Alternaria and Fusarium spp. were isolated from seeds. The presence of a bacterium on the seeds was observed. The delay in harvest and high humidity increased the number of seeds from which Phomopsis was recovered.

Coevolution of hosts and microorganisms: an analysis of the involvment of cytokines in host-parasite interactions

Parasites may employ particular strategies of eluding an immune response by taking advantage of those mechanisms that normally guarantee immunological self-tolerance. Much in the way as it occurs during the establishment of self-tolerance, live pathogens may induce clonal deletion, functional inactivation(anergy) and immunosupression. At this latter level, it appears that certain pathogens produce immunosupresive cytokine-like mediators or provoke like host the secrete cytokines that will compromise the anti-parasite immune response. It appears that immune responses that preferentially involve T helper l cells (secretors of interleukin-2-and interferon-y) tend to be protective, whereas T helper 2 cells (secretors of IL-4, IL5, IL-6, and IL-10), a population that antagonizes T helper cells, mediate disease susceptibility and are immunopathological reactions. Cytokines produced by T helper 2 cells mediate many symptoms of infection, including eosinophilia, mastocytosis, hyperimmunoglobulinemia, and elevated IgE levels. Administration of IL-2 and IFN-y has beneficial effects in many infections mediated by viruses, bacteria, and protozoa. The use of live vaccinia virus might be an avenue for the treatment of or vaccination against infection. We have found that a vaccinia virus expressing the gene for human IL-2, though attenuated, precipitates autoimmune disease in immunodeficient athymic mice. Thus, although T helper l cytokines may have desired immunostimulatory properties, they also may lead to unwarranted autoaggressive responses.

Detection of extracellular proteases from microorganisms on agar plates

We present herein an improved assay for detecting the presence of extracellular proteases from microorganisms on agar plates. Using different substrates (gelatin, BSA, hemoglobin) incorporated into the agar and varying the culture medium composition, we were able to detect proteolytic activities from Pseudomonas aeruginosa, Micrococcus luteus and Serratia marcescens as well as the influence that these components displayed in the expression of these enzymes. For all microorganisms tested we found that in agar-BHI or yeast extract medium containing gelatin the sensitivity of proteinase detection was considerably greater than in BSA-agar or hemoglobin-agar. However, when BSA or hemoglobin were added to the culture medium, there was an increase in growth along with a marked reduction in the amount of proteinase production. In the case of M. luteus the incorporation of glycerol in BHI or yeast extract gelatin-agar induced protease liberation. Our results indicate that the technique described here is of value for detecting extracellular proteases directly in the culture medium, by means of a qualitative assay, simple, inexpensive, straight forward method to assess the presence of the proteolytic activity of a given microorganism colony with great freedom in substrate selection.

First isolation of microorganisms from the gut diverticulum of Aedes aegypti (Diptera: Culicidae): new perspectives for an insect-bacteria association

We show for the first time that the ventral diverticulum of the mosquito gut (impermeable sugar storage organ) harbors microorganisms. The gut diverticulum from newly emerged and non-fed Aedes aegypti was dissected under aseptic conditions, homogenized and plated on BHI medium. Microbial isolates were identified by sequencing of 16S rDNA for bacteria and 28S rDNA for yeast. A direct DNA extraction from Ae. aegypti gut diverticulum was also performed. The bacterial isolates were: Bacillus sp., Bacillus subtilis and Serratia sp. The latter was the predominant bacteria found in our isolations. The yeast species identified was Pichia caribbica.

Helicobacter pylori detection in gastric biopsies, saliva and dental plaque of Brazilian dyspeptic patients

Helicobacter pylori is an important human pathogen that causes chronic gastritis and is associated with the development of peptic ulcer disease and gastric malignancies. The oral cavity has been implicated as a potential H. pylori reservoir and may therefore be involved in the reinfection of the stomach, which can sometimes occur following treatment of an H. pylori infection. The objectives of this paper were (i) to determine the presence of H. pylori in the oral cavity and (ii) to examine the relationship between oral H. pylori and subsequent gastritis. Gastric biopsies, saliva samples and dental plaques were obtained from 78 dyspeptic adults. DNA was extracted and evaluated for the presence of H. pylori using polymerase chain reaction and Southern blotting methods. Persons with gastritis were frequently positive for H. pylori in their stomachs (p < 0.0001) and there was a statistically significant correlation between the presence of H. pylori in gastric biopsies and the oral cavity (p < 0.0001). Our results suggest a relationship between gastric infection and the presence of this bacterium in the oral cavity. Despite this, H. pylori were present in the oral cavity with variable distribution between saliva and dental plaques, suggesting the existence of a reservoir for the species and a potential association with gastric reinfection.