Ação da histatina 5, uma proteína antimicrobiana, no desenvolvimento de biofilmes de Candida Albicans

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Dynamics of biofilm formation and the interaction between candida albicans and methicillin-susceptible (MSSA) and -resistant staphylococcus aureus (MRSA)

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Lactobacillus acidophilus ATCC 4356 inhibits biofilm formation by C. albicans and attenuates the experimental candidiasis in Galleria mellonella

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Investigation of biofilm production and icaA and icaD genes in Staphylococcus aureus isolated from heifers and cows with mastitis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Microfluidic electronic tongue

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Sub-MICs of Mentha piperita essential oil and menthol inhibits AHL mediated quorum sensing and biofilm of Gram-negative bacteria

Bacterial quorum sensing (QS) is a density dependent communication system that regulates the expression of certain genes including production of virulence factors in many pathogens. Bioactive plant extract/compounds inhibiting QS regulated gene expression may be a potential candidate as antipathogenic drug. In this study anti-QS activity of peppermint (Menthe piperita) oil was first tested using the Chromobacterium violaceum CVO26 biosensor. Further, the findings of the present investigation revealed that peppermint oil (PMO) at sub-Minimum Inhibitory Concentrations (sub-MICs) strongly interfered with acyl homoserine lactone (AHL) regulated virulence factors and biofilm formation in Pseudomonas aeruginosa and Aeromonas hydrophila. The result of molecular docking analysis attributed the QS inhibitory activity exhibited by PMO to menthol. Assessment of ability of menthol to interfere with QS systems of various Gram-negative pathogens comprising diverse AHL molecules revealed that it reduced the AHL dependent production of violacein, virulence factors, and biofilm formation indicating broad-spectrum anti-QS activity. Using two Escherichia colt biosensors, MG4/pKDT17 and pEAL08-2, we also confirmed that menthol inhibited both the las and pqs QS systems. Further, findings of the in vivo studies with menthol on nematode model Caenorhabditis elegans showed significantly enhanced survival of the nematode. Our data identified menthol as a novel broad spectrum QS inhibitor.

Three-dimensional aspects of the lingual papillae and their connective tissue cores in the tongue of rats: a scanning electron microscope study

The aim of the present study was to describe the tridimensional morphological characteristics of the lingual papillae and their connective tissue cores (CTCs) in Sprague Dawley rats. Four types of papillae were reported on the dorsal surface. Filiform papillae were distributed on the tongue surface and after epithelial maceration a conic and multifilamentary shape of the CTCs was revealed. Fungiform papillae were reported on the rostral and middle regions covered by a squamous epithelium. After the removal of the epithelium, the shape of a volcano with the taste orifice at its top was noted. Foliate papillae were composed of five pairs of epithelial folds situated on the lateral-caudal margin of the tongue. After the removal of the epithelium, they were shown to be limited by thin laminar projections. The vallate papilla with an oval shape was present in the caudal region and delimited by an incomplete groove. The morphological characteristics of the lingual papillae of Sprague Dowley rats, three-dimensional SEM images, and the types of papillae on the dorsal surface were similar to those reported previously in other rodent mammals. The maceration technique revealed the details of extracellular matrix with varied shapes form of connective tissue cores.

Essential oil of Melaleuca alternifolia for the treatment of oral candidiasis induced in an immunosuppressed mouse model

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Condyloma acuminata in the tongue and palate of a sexually abused child: a case report

Condyloma acuminata caused by human papilloma viruses, (HPV) is a sexually transmitted disease (STD) appearing most frequently as soft, pink cauliflower like growths in moist areas, such as the genitalia, mouth and other places. The disease is highly contagious, can appear singly or in groups, small or large. In children, the isolation of a sexually transmitted organism may be the first indication that an abuse has occurred. Although the presence of a sexually transmissible agent from a child beyond the neonatal period is suggestive of sexual abuse, exceptions do exist. The authors report the clinical case of a five-year-old Caucasian male with lesions located in the dorsal surfaces of the posterior tongue and palate. Both lesions had a firm consistency, reddish appearance and presence of whitish areas and regions of ulceration. During the interview, the mother reported that the boy had been sexually abused. Sexually transmitted disease may occur during sexual abuse. Dentists as well as pediatricians have a role to play in identifying and treating these children. The diagnosis is essentially clinical (anamnesis and physical examination), but also the use of cytology eventually resorts to biopsy of the suspicious lesions for histological examination. The therapeutic option was the excision of the lesions.

Antioxidant activity of apple extract protects against rat tongue carcinogenesis induced by 4-nitroquinoline 1-oxide

Several studies have shown that apple (Malus sp.) has many components able to exert chemopreventive activity. The aim of this study was to evaluate the chemopreventive potential of apple extract following medium-term oral carcinogenesis assay induced by 4-nitroquinoline 1-oxide (4NQO) by means of histopathological analysis and gene expression of antioxidant enzymes, such as CuZnSOD, MnSOD and catalase. A total of 30 male Wistar rats were distributed into five groups, as follows (n = 6 per group): Group 1 - negative control group (non-treated group); Group 2 - received 4NQO during 8 weeks in drinking water and treated with apple extract by gavage between the 1st and 4th weeks daily (initiation phase); Group 3 - received 4NQO for 8 weeks in drinking water and treated with apple extract by gavage between the 5th and 8th weeks daily (promotion phase); Group 4 - received apple extract by gavage for eight consecutive weeks only; and Group 5 - received 4NQO for 8 weeks in drinking water daily. Histopathological analysis revealed that apple extract protect oral lesions induced by 4NQO at initiation or promotion phase. Higher gene expression of CuZnSOD and MnSOD enzymes were noticed in groups treated with apple extract as well. Taken together, our results demonstrate that the apple extract is able to modulate medium-term oral carcinogenesis assay as a result of antioxidant activity.

Effect of UV-photofunctionalization on oral bacterial attachment and biofilm formation to titanium implant material

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Effect of essential oils of Syzygium aromaticum and Cinnamomum zeylanicum and their major components on biofilm production in Staphylococcus aureus strains isolated from milk of cows with mastitis

Bovine mastitis is an inflammation of the mammary glands of cows and causes significant economic losses in dairy cattle. Staphylococcus aureus is one of the microorganisms most commonly isolated. Novel agents are required in agricultural industries to prevent the development of mastitis. The production of biofilm by Staph. aureus facilitates the adhesion of bacteria to solid surfaces and contributes to the transmission and maintenance of these bacteria. The effect of the essential oils of Syzygium aromaticum (clove; EOSA) and Cinnamomum zeylanicum (cinnamon; EOCZ) and their major components, eugenol and cinnamaldehyde, on Staph. aureus biofilm formation on different surfaces was investigated. The results showed a significant inhibition of biofilm production by EOSA on polystyrene and stainless steel surfaces (69.4 and 63.6%, respectively). However, its major component, eugenol, was less effective on polystyrene and stainless steel (52.8 and 19.6%, respectively). Both EOCZ and its major component, cinnamaldehyde, significantly reduced biofilm formation on polystyrene (74.7 and 69.6%, respectively) and on stainless steel surfaces (45.3 and 44.9%, respectively). These findings suggest that EOSA, EOCZ, and cinnamaldehyde may be considered for applications such as sanitization in the food industry.

The effect of blue light on periodontal biofilm growth in vitro

We have previously shown that blue light eliminates the black-pigmented oral bacteria Porphyromonas gingivalis, Prevotella intermedia, Prevotella nigrescens, and Prevotella melaninogenica. In the present study, the in vitro photosensitivity of the above black-pigmented microorganisms and four Fusobacteria species (Fusobacterium nucleatum ss. nucleatum, F. nucleatum ss. vincentii, F. nucleatum ss. polymorphum, Fusobacterium periodonticum) was investigated in pure cultures and human dental plaque suspensions. We also tested the hypothesis that phototargeting the above eight key periodontopathogens in plaque-derived biofilms in vitro would control growth within the dental biofilm environment. Cultures of the eight bacteria were exposed to blue light at 455 nm with power density of 80 mW/cm(2) and energy fluence of 4.8 J/cm(2). High-performance liquid chromatography (HPLC) analysis of bacteria was performed to demonstrate the presence and amounts of porphyrin molecules within microorganisms. Suspensions of human dental plaque bacteria were also exposed once to blue light at 455 nm with power density of 50 mW/cm(2) and energy fluence of 12 J/cm(2). Microbial biofilms developed from the same plaque were exposed to 455 nm blue light at 50 mW/cm(2) once daily for 4 min (12 J/cm(2)) over a period of 3 days (4 exposures) in order to investigate the cumulative action of phototherapy on the eight photosensitive pathogens as well as on biofilm growth. Bacterial growth was evaluated using the colony-forming unit (CFU) assay. The selective phototargeting of pathogens was studied using whole genomic probes in the checkerboard DNA-DNA format. In cultures, all eight species showed significant growth reduction (p < 0.05). HPLC demonstrated various porphyrin patterns and amounts of porphyrins in bacteria. Following phototherapy, the mean survival fractions were reduced by 28.5 and 48.2 % in plaque suspensions and biofilms, respectively, (p < 0.05). DNA probe analysis showed significant reduction in relative abundances of the eight bacteria as a group in plaque suspensions and biofilms. The cumulative blue light treatment suppressed biofilm growth in vitro. This may introduce a new avenue of prophylactic treatment for periodontal diseases.

The beneficial effect of equisetum giganteum L. against candida biofilm formation: new approaches to denture stomatitis

Equisetum giganteum L. (E. giganteum), Equisetaceae, commonly called giant horsetail, is an endemic plant of Central and South America and is used in traditional medicine as diuretic and hemostatic in urinary disorders and in inflammatory conditions among other applications. The chemical composition of the extract EtOH 70% of E. giganteum has shown a clear presence of phenolic compounds derived from caffeic and ferulic acids and flavonoid heterosides derived from quercitin and kaempferol, in addition to styrylpyrones. E. giganteum, mainly at the highest concentrations, showed antimicrobial activity against the relevant microorganisms tested: Escherichia coli, Staphylococcus aureus, and Candida albicans. It also demonstrated antiadherent activity on C. albicans biofilms in an experimental model that is similar to dentures. Moreover, all concentrations tested showed anti-inflammatory activity. The extract did not show cytotoxicity in contact with human cells. These properties might qualify E. giganteum extract to be a promising alternative for the topic treatment and prevention of oral candidiasis and denture stomatitis.