RESUMEN

The emergence of infections caused by microorganisms in the oral cavity and increasing concerns regarding the use of antibiotics have resulted in the development of novel antimicrobial molecules, such as antimicrobial synthetic peptides. The purpose of this study was to evaluate the antimicrobial and antibiofilm activities of the native peptide KR-12 and its derivative, the synthetic peptide [W7]KR12-KAEK, against planktonic and biofilms Enterococcus faecalis strains. The methods used to evaluate the antimicrobial activity in planktonic cultures include minimum inhibitory concentration and minimum bactericidal concentration assays. The effects of [W7]KR12-KAEK on biofilm formation and mature biofilms were evaluated by quantifying biomass (crystal violet staining) and counting colony-forming units. Structural assessments of the biofilms and cellular morphological changes were performed using scanning electron microscopy. Peptide [W7]KR12-KAEK showed potential antimicrobial activity against planktonic cells. Interestingly, the native peptide KR-12 showed no antimicrobial activity. Moreover, it inhibited biofilm formation and disrupted the mature biofilms of E. faecalis strains. These results suggest that [W7]KR12-KAEK may be a potential molecule for the development of auxiliary antimicrobial therapies against oral infections.

Asunto(s)

RESUMEN

AIM: The objective of this study was to evaluate the inflammatory process resulting from the use of two cyanoacrylate-based adhesives to stabilize grafts. METHODOLOGY: A total of 45 male Wistar rats were randomly divided into three groups (n = 15/group) treated with ethyl cyanoacrylate glue (TG1), octyl-2-cyanoacrylate glue (TG2) or suture threads (CG). After de-epithelialization in the anterior gingival region of the mandible, the graft was removed from the donor site (hard palate), taken to the recipient site and stabilized according to the protocol of each group. After 7, 14, and 45 days, the animals were euthanized. The graft area was analysed macroscopically, histologically, histochemically (Masson trichrome), and immunohistochemically positive cell count for TGF-ß, α-SMA, RANKL, OPG, FGF, and IL-10. The Kruskal-Wallis/Dunn test (SPSS 20.0, p < 0.05) was used for analysis. RESULTS: There was no difference in the clinical parameters among the three groups, but TG1 showed the lowest mononuclear inflammatory cell count and the highest amount of total collagen. FGF immunoexpression was significantly higher for the CG group, but the TG2 showed a significant reduction in the RANKL/OPG ratio. CONCLUSION: TG1 had a mild inflammatory response and a higher collagen deposition than other glues, and TG2 had a reduction in the RANKL / OPG ratio.

RESUMEN

Ontogenetic changes in venom composition have been described in Bothrops snakes, but only a few studies have attempted to identify the targeted paralogues or the molecular mechanisms involved in modifications of gene expression during ontogeny. In this study, we decoded B. jararacussu venom gland transcripts from six specimens of varying sizes and analyzed the variability in the composition of independent venom proteomes from 19 individuals. We identified 125 distinct putative toxin transcripts, and of these, 73 were detected in venom proteomes and only 10 were involved in the ontogenetic changes. Ontogenetic variability was linearly related to snake size and did not correspond to the maturation of the reproductive stage. Changes in the transcriptome were highly predictive of changes in the venom proteome. The basic myotoxic phospholipases A2 (PLA2s) were the most abundant components in larger snakes, while in venoms from smaller snakes, PIII-class SVMPs were the major components. The snake venom metalloproteinases (SVMPs) identified corresponded to novel sequences and conferred higher pro-coagulant and hemorrhagic functions to the venom of small snakes. The mechanisms modulating venom variability are predominantly related to transcriptional events and may consist of an advantage of higher hematotoxicity and more efficient predatory function in the venom from small snakes.

RESUMEN

Approximately 140 snake species are known to occur in the Atlantic Forest with nearly half being endemic to this ecoregion. However, the Atlantic forest is one of the most threatened tropical ecoregions, with only 16% of its original area remaining as forest. This extensive habitat loss must have had a negative effect on its snake fauna. Indeed, 53% of the threatened snakes of Brazil occur in the Atlantic forest. Therefore, basic natural history information that can potentially contribute to the conservation of Atlantic forest snakes are urgently needed. Here the natural history of a snake assemblage at Etá Farm region, Sete Barras municipality, south-eastern Brazil is described, and a visual guide and an identification key provided that can be used by researchers and local people to identify snakes from this region. Most of the species found in the field use both open areas and forests, are primarily terrestrial, present diurnal activity, and include frogs in their diet. A higher number of enlarged follicles, eggs, and/or embryos were recorded during the warm and rainy season. Seventeen different types of defensive tactics were recorded in the species found in the field. This study provides useful information for understanding the structure of snake assemblages of the Atlantic Forest and is potentially useful for conservation assessments and for designing conservation plans

RESUMEN

This study focuses on the parasitic associations of mites and ticks infesting reptiles and amphibians through a multifocal approach. Herein, reptiles (n= 3,596) and amphibians (n= 919) were examined to ensure representativeness of the Brazilian herpetofauna megadiversity. The overall prevalence was calculated to better understand which were the preferred hosts for each order of Acari (Trombidiformes, Mesostigmata and Ixodida), as well as to determine which orders frequently parasitize reptiles and amphibians in Brazil, and their host specificity. Infestation rates were calculated [prevalence, mean intensity (MI) and mean abundance (MA)] for each order and species, determining which mites and ticks are more likely to be found parasitizing the ectothermic tetrapod fauna. Parasitic niches and preferred locations were recorded to help identify specific places exploited by different Acari, and to determine the host-parasite adaptations, specificity, and relationships in terms of co-evolution. In total 4,515 reptiles and amphibians were examined, of which 170 specimens were infested by mites and ticks (overall prevalence of 3.8%). Trombidiformes mites were prevalent in lizards (55.3%), followed by Ixodida on snakes (24.7%). Mesostigmata mites were the less prevalent, being identified only on Squamata reptiles (4.3% on snakes, 2.4% on lizards). In amphibians, Ixodida ticks were the most prevalent (63.2%), followed by Trombidiformes (34.6%), and lastly Oribatida (2%). From the 13 species of Trombidiformes identified, Eutrombicula alfreddugesi (19.9 %) was the most abundant in terms of number of host species and infested individuals. Specimens of Ixodida, yet more common, showed low preferred locations and different values of infestation rates. Co-infestations were recorded only on snakes. Lizard mites generally adhered to the ventral celomatic area (Pterygosomatidae), and some species to the pocket-like structures (Trombiculidae). Lizards, at variance from snakes, have adapted to endure high parasitic loads with minimum effects on their health. The high number of mites recorded in the digits of toads (Cycloramphus boraceiensis, Corythomantis greening, Cycloramphus dubius, Leptodactylus latrans, Melanophryniscus admirabilis) could lead to avascular necrosis. Frogs were often infested by Hannemania larvae, while Rhinella toads were likely to be infested by Amblyomma ticks. Of note, Rhinella major toad was found infested by an oribatid mite, implying first a new parasitic relationship. The effect of high parasitic loads on critically endangered species of anurans deserves further investigation. Our results add basic knowledge to host association of mites and ticks to Brazilian reptiles and amphibians, highlighting that routine ectoparasite examination is needed in cases of quarantine as well as when for managing reptiles and amphibians in captivity given the wide diversity of Acari on the Brazilian ectothermic tetrapod fauna.

RESUMEN

Approximately 140 snake species are known to occur in the Atlantic Forest with nearly half being endemic to this ecoregion. However, the Atlantic forest is one of the most threatened tropical ecoregions, with only 16% of its original area remaining as forest. This extensive habitat loss must have had a negative effect on its snake fauna. Indeed, 53% of the threatened snakes of Brazil occur in the Atlantic forest. Therefore, basic natural history information that can potentially contribute to the conservation of Atlantic forest snakes are urgently needed. Here the natural history of a snake assemblage at Etá Farm region, Sete Barras municipality, south-eastern Brazil is described, and a visual guide and an identification key provided that can be used by researchers and local people to identify snakes from this region. Most of the species found in the field use both open areas and forests, are primarily terrestrial, present diurnal activity, and include frogs in their diet. A higher number of enlarged follicles, eggs, and/or embryos were recorded during the warm and rainy season. Seventeen different types of defensive tactics were recorded in the species found in the field. This study provides useful information for understanding the structure of snake assemblages of the Atlantic Forest and is potentially useful for conservation assessments and for designing conservation plans

RESUMEN

This study focuses on the parasitic associations of mites and ticks infesting reptiles and amphibians through a multifocal approach. Herein, reptiles (n= 3,596) and amphibians (n= 919) were examined to ensure representativeness of the Brazilian herpetofauna megadiversity. The overall prevalence was calculated to better understand which were the preferred hosts for each order of Acari (Trombidiformes, Mesostigmata and Ixodida), as well as to determine which orders frequently parasitize reptiles and amphibians in Brazil, and their host specificity. Infestation rates were calculated [prevalence, mean intensity (MI) and mean abundance (MA)] for each order and species, determining which mites and ticks are more likely to be found parasitizing the ectothermic tetrapod fauna. Parasitic niches and preferred locations were recorded to help identify specific places exploited by different Acari, and to determine the host-parasite adaptations, specificity, and relationships in terms of co-evolution. In total 4,515 reptiles and amphibians were examined, of which 170 specimens were infested by mites and ticks (overall prevalence of 3.8%). Trombidiformes mites were prevalent in lizards (55.3%), followed by Ixodida on snakes (24.7%). Mesostigmata mites were the less prevalent, being identified only on Squamata reptiles (4.3% on snakes, 2.4% on lizards). In amphibians, Ixodida ticks were the most prevalent (63.2%), followed by Trombidiformes (34.6%), and lastly Oribatida (2%). From the 13 species of Trombidiformes identified, Eutrombicula alfreddugesi (19.9 %) was the most abundant in terms of number of host species and infested individuals. Specimens of Ixodida, yet more common, showed low preferred locations and different values of infestation rates. Co-infestations were recorded only on snakes. Lizard mites generally adhered to the ventral celomatic area (Pterygosomatidae), and some species to the pocket-like structures (Trombiculidae). Lizards, at variance from snakes, have adapted to endure high parasitic loads with minimum effects on their health. The high number of mites recorded in the digits of toads (Cycloramphus boraceiensis, Corythomantis greening, Cycloramphus dubius, Leptodactylus latrans, Melanophryniscus admirabilis) could lead to avascular necrosis. Frogs were often infested by Hannemania larvae, while Rhinella toads were likely to be infested by Amblyomma ticks. Of note, Rhinella major toad was found infested by an oribatid mite, implying first a new parasitic relationship. The effect of high parasitic loads on critically endangered species of anurans deserves further investigation. Our results add basic knowledge to host association of mites and ticks to Brazilian reptiles and amphibians, highlighting that routine ectoparasite examination is needed in cases of quarantine as well as when for managing reptiles and amphibians in captivity given the wide diversity of Acari on the Brazilian ectothermic tetrapod fauna.

RESUMEN

The Serra da Mantiqueira is one of the least inventoried physiographic areas of southeastern Brazil. There is great potential for detection of endemic species for which little or nothing is known about basic aspects of natural history. The Parque Estadual da Serra do Papagaio (PESP) within the Serra da Mantiqueira is an area of extreme biological importance because it houses mixed formations of grasslands, ombrophilous forests, and enclaves of Araucaria forests (mixed ombrophilous forest). Currently, the mixed ombrophilous forest covers less than 5% of its original range and areas occupied by this forest type, and associated ecosystems constitute refuges, housing several endemic, high altitude species. Between September 2015 and April 2016, field samplings were performed in the PESP using four distinct methods. The objective was to determine the composition and natural history of snakes from an isolated, high altitude area of the Serra da Mantiqueira. In PESP and surrounding areas, 80 individuals representing 24 species, 19 genera, and three families were recorded. Data are presented on abundance, habitat, daily activity, diet, reproduction, and defense. Comparison of the PESP snake assemblage with 30 other Atlantic Forest areas in southeastern Brazil indicate the Serra da Mantiqueira presents particular characteristics regarding snake composition.

RESUMEN

Objetivo: avaliar a atividade antimicrobiana da fibrina rica em plaquetas (PRF) frente a bactérias da cavidade oral. Material e métodos: foram coletadas amostras sanguíneas de seis pacientes que fizeram uso de PRF para fins de tratamento odontológico. Após a coleta, o sangue foi centrifugado seguindo duas metodologias distintas, uma a 1.800 rpm durante dez minutos e outra a 3.000 rpm durante dez minutos. A PRF obtida pelo processo foi separada e imediatamente utilizada para análise de sua atividade antimicrobiana. As cepas Streptococccus mutans, Streptococcus oralis, Streptococcus salivarius, Streptococcus parasanguinis, Streptococcus mitis, Lactobacillus acidophilus e Lactobacillus rhamnosus foram cultivadas em meio Brain Heart Infusion (BHI) suplementado com 1% de sacarose, sob atmosfera de microaerofilia a 37oC durante 48 horas. O potencial bactericida da PRF foi verificado através do teste de resistência ou sensibilidade bacteriana por difusão em ágar. Resultados: após a obtenção dos resultados, pôde-se observar que algumas bactérias, como a S. mutans, S. oralis, S. sanguise e S. parasanguinis, foram suscetíveis à PRF, segundo medição do halo de inibição. Ainda, houve diferenças quanto à atividade da PRF dentre as duas metodologias empregadas. Conclusão: a PRF possui atividade antimicrobiana considerável frente a determinadas espécies bacterianas orais, fato este que a torna um excelente produto para uso em Odontologia. Contudo, outros estudos devem ser realizados visando o mecanismo de ação antimicrobiana deste recurso. (AU)

Objective: to evaluate the antimicrobial activity of platelet-rich fibrin (PRF) against oral bacteria. Material and methods: blood samples were collected from 6 patients who used PRF for dental treatment. After collection, the blood was centrifuged following two different methodologies, one at 1,800 rpm for 10 minutes and the other at 3,000 rpm for 10 minutes. The PRF obtained by the process was separated and immediately used to analyze its antimicrobial activity. Streptococcus mutans, Streptococcus oralis, Streptococcus salivarius, Streptococcus parasanguinis, Streptococcus sanguis, Lactobacillus acidophilus and Lactobacillus rhamnosus were cultured in Brain Heart Infusion (BHI) supplemented with 1% sucrose under a microaerophilic atmosphere at 37oC for 48 hours. The bactericidal potential of the PRF was verified through the bacterial resistance test by diffusion in agar. Results: after obtaining the results, it was observed that some bacteria such as S. mutans, S. oralis, S. sanguis and S. parasanguinis were susceptible to PRF according to the measurement of the inhibition halo. It was also observed that there were differences in PRF activity among the two methodologies used. Conclusion: it was possible to perceive that PRF has considerable antimicrobial activity against certain oral bacterial species, a fact that makes it an excellent product for use in dentistry. However, other studies still needed to be performed aiming at the mechanisms of antimicrobial action of this resource. (AU)

Asunto(s)

RESUMEN

Objetivo: realizar um levantamento sistemático da literatura no que tange ao uso de peptídeos antimicrobianos contra periodontopatógenos e indicar quais os peptídeos e micro-organismos mais estudados, com o objetivo final de traçar um perfil das publicações na área. Material e métodos: a busca por artigos ocorreu na base de dados Pubmed, com os seguintes critérios de inclusão: publicação nos últimos dez anos; palavras-chave "Antimicrobial Peptide" and "Periodontal" and "Bacteria", publicados em inglês e disponíveis gratuitamente na íntegra para leitura. Um total de dez artigos foram selecionados após o refinamento dos dados. Resultados: apesar do pequeno número de estudos encontrados, evidencia-se o potencial uso de peptídeos antimicrobianos no controle das principais bactérias periodontopatogênicas. Além disso, os peptídeos produzidos por células da mucosa oral (Defensinas, LL-37 e Histatinas), bem como os micro-organismos Porphyromonas gingivalis e Fusobacterium nucleatum, foram os mais estudados. Conclusão: é possível concluir que o uso de peptídeos antimicrobianos como potencial ferramenta no controle microbiano tem uma importância crescente, provavelmente devido à sua ampla aplicabilidade, mecanismos de ação e baixos índices de resistência. Contudo, estudos relacionados à sua toxicidade sobre células humanas, modo de aplicação e ensaios clínicos precisam ser realizados.

Objectives: to perform a systematic review of the literature regarding the use of antimicrobial peptides against periodontopathogens and indicate the most studied peptides and microorganisms, with the final objective of outlining a profile of publications in the area. Material and methods: the search for articles occurred in Pubmed database with the following inclusion criteria: publication in the last 10 years; Keywords "Antimicrobial Peptide" and "Periodontal" and "Bacteria", published in English and freely available for reading. Results: a total of 10 articles were selected after refi ning the data. Despite the small number of studies found, it is evident the potential use of antimicrobial peptides in the control of the main periodontopathogenic bacteria. In addition, the peptides produced by oral mucosa cells (Defensins, LL-37 and Histatins) as well as the microorganisms Porphyromonas gingivalis and Fusobacterium nucleatum were the most studied. Conclusion: it is possible to conclude that the use of antimicrobial peptides as a tool in microbial control is of increasing importance, probably due to their wide applicability, mechanisms of action and low resistance indices. However, studies related to its toxicity on human cells, mode of application and clinical trials still need to be performed.

Asunto(s)

RESUMEN

The Serra da Mantiqueira is one of the least inventoried physiographic areas of southeastern Brazil. There is great potential for detection of endemic species for which little or nothing is known about basic aspects of natural history. The Parque Estadual da Serra do Papagaio (PESP) within the Serra da Mantiqueira is an area of extreme biological importance because it houses mixed formations of grasslands, ombrophilous forests, and enclaves of Araucaria forests (mixed ombrophilous forest). Currently, the mixed ombrophilous forest covers less than 5% of its original range and areas occupied by this forest type, and associated ecosystems constitute refuges, housing several endemic, high altitude species. Between September 2015 and April 2016, field samplings were performed in the PESP using four distinct methods. The objective was to determine the composition and natural history of snakes from an isolated, high altitude area of the Serra da Mantiqueira. In PESP and surrounding areas, 80 individuals representing 24 species, 19 genera, and three families were recorded. Data are presented on abundance, habitat, daily activity, diet, reproduction, and defense. Comparison of the PESP snake assemblage with 30 other Atlantic Forest areas in southeastern Brazil indicate the Serra da Mantiqueira presents particular characteristics regarding snake composition.

RESUMEN

We provide information on the diversity and natural history of anurans from preserved and disturbed habitats in the region of Eta Farm, municipality of Sete Barras, state of Sao Paulo, Brazil. The region is covered by rainforest and plantations of banana and peach palm. From April, 2013 to March, 2014 we sampled amphibians mainly with pitfall traps with drift fences and visual and auditory surveys. A total of 9813 individuals of 36 species of anurans from nine families were recorded in this study. A larger number of species was found in forests (29 species), followed by peach palm plantations (21 species), and banana plantations (17 species). The areas of peach palm plantation and forests showed the greatest similarity in species composition. The vegetation type with the highest number of exclusive species was the forest, whereas only four species were exclusive of the peach palm plantation, and none was exclusive of the banana plantation. Species accumulation curves indicated that our sampling effort was not enough to sample all the species that occur in the region. Our results reinforce the importance of forested habitats for the maintenance of anuran diversity in the Atlantic forest. The preservation of large fragments of forest in the region of Eta Farm is necessary to preserve the diverse amphibian fauna of this region.

RESUMEN

Abstract: We provide information on the diversity and natural history of anurans from preserved and disturbed habitats in the region of Etá Farm, municipality of Sete Barras, state of São Paulo, Brazil. The region is covered by rainforest and plantations of banana and peach palm. From April, 2013 to March, 2014 we sampled amphibians mainly with pitfall traps with drift fences and visual and auditory surveys. A total of 9813 individuals of 36 species of anurans from nine families were recorded in this study. A larger number of species was found in forests (29 species), followed by peach palm plantations (21 species), and banana plantations (17 species). The areas of peach palm plantation and forests showed the greatest similarity in species composition. The vegetation type with the highest number of exclusive species was the forest, whereas only four species were exclusive of the peach palm plantation, and none was exclusive of the banana plantation. Species accumulation curves indicated that our sampling effort was not enough to sample all the species that occur in the region. Our results reinforce the importance of forested habitats for the maintenance of anuran diversity in the Atlantic forest. The preservation of large fragments of forest in the region of Etá Farm is necessary to preserve the diverse amphibian fauna of this region.

Resumo: Neste estudo são apresentadas informações sobre diversidade e história natural de anuros de área preservadas e perturbadas na região da Fezenda Etá, município de Sete Barras, estado de São Paulo, Brasil. A região é coberta por florestas e plantações de pupunha e banana. De abril de 2013 a março de 2014 nós amostramos anuros principalmente com armadilhas de queda com cercas-guia e por meio de procura visual e auditiva. Um total de 9.813 indivíduos de 36 espécies de nove famílias foram registrados. Um número maior de espécies foi encontrado nas florestas (29 espécies), seguidas pelas plantações de pupunha (21 espécies) e de banana (17 espécies). As áreas de plantação de pupunha e as florestas tiveram a maior similaridade em composição de espécies. O tipo de vegetação com o maior número de espécies exclusivas foi a floresta, ao passo que somente quatro espécies foram encontradas exclusivamente na plantação de pupunha e nenhuma foi exclusiva de bananais. As curvas de acumulação de espécies indicaram que nosso esforço amostral não foi suficiente para amostrar todas as espécies que ocorrem na região. Nossos estudos reforçam a importância de ambientes florestados para a manutenção da diversidade de anfíbios na Mata Atlântica. A preservação de grandes fragmentos de floresta é imprescindível para a conservação da rica fauna de anfíbios da região da Fazenda Etá.

RESUMEN

The Serra da Mantiqueira is one of the least inventoried physiographic areas of southeastern Brazil. There is great potential for detection of endemic species for which little or nothing is known about basic aspects of natural history. The Parque Estadual da Serra do Papagaio (PESP) within the Serra da Mantiqueira is an area of extreme biological importance because it houses mixed formations of grasslands, ombrophilous forests, and enclaves of Araucaria forests (mixed ombrophilous forest). Currently, the mixed ombrophilous forest covers less than 5% of its original range and areas occupied by this forest type, and associated ecosystems constitute refuges, housing several endemic, high altitude species. Between September 2015 and April 2016, field samplings were performed in the PESP using four distinct methods. The objective was to determine the composition and natural history of snakes from an isolated, high altitude area of the Serra da Mantiqueira. In PESP and surrounding areas, 80 individuals representing 24 species, 19 genera, and three families were recorded. Data are presented on abundance, habitat, daily activity, diet, reproduction, and defense. Comparison of the PESP snake assemblage with 30 other Atlantic Forest areas in southeastern Brazil indicate the Serra da Mantiqueira presents particular characteristics regarding snake composition.

RESUMEN

We provide information on the diversity and natural history of anurans from preserved and disturbed habitats in the region of Eta Farm, municipality of Sete Barras, state of Sao Paulo, Brazil. The region is covered by rainforest and plantations of banana and peach palm. From April, 2013 to March, 2014 we sampled amphibians mainly with pitfall traps with drift fences and visual and auditory surveys. A total of 9813 individuals of 36 species of anurans from nine families were recorded in this study. A larger number of species was found in forests (29 species), followed by peach palm plantations (21 species), and banana plantations (17 species). The areas of peach palm plantation and forests showed the greatest similarity in species composition. The vegetation type with the highest number of exclusive species was the forest, whereas only four species were exclusive of the peach palm plantation, and none was exclusive of the banana plantation. Species accumulation curves indicated that our sampling effort was not enough to sample all the species that occur in the region. Our results reinforce the importance of forested habitats for the maintenance of anuran diversity in the Atlantic forest. The preservation of large fragments of forest in the region of Eta Farm is necessary to preserve the diverse amphibian fauna of this region.

RESUMEN

This study evaluated the antimicrobial effect of 3ß,6ß,16ß-trihydroxylup-20(29)-ene (CLF1), a triterpene isolated from Combretum leprosum Mart., in inhibiting the planktonic growth and biofilms of Gram positive bacteria Streptococcus mutans and S. mitis. The antimicrobial activity was assessed by determining the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The antibiofilm potential was determined by quantifying total biomass and enumerating biofilm-entrapped viable bacteria. In addition, the acute toxicity of CLF1 on Artemia sp. nauplii was also determined. The results showed that CLF1 was able in inhibiting the growth of S. mutans and S. mitis with MIC and MBC of 7.8 µg/mL and 15.6 µg/mL, respectively. CLF1 was highly effective on biofilms of both bacteria. Only 7.8 µg/mL CLF1 was enough to inhibit by 97% and 90% biomass production of S. mutans and S. mitis, respectively. On the other hand, such effects were not evident on Gram negative Pseudomonas aeruginosa and Klebsiella oxytoca. The toxicity tests showed that the LC50 of CLF1 was 98.19 µg/mL. Therefore, CLF1 isolated from C. leprosum may constitute an important natural agent for the development of new therapies for caries and other infectious diseases caused by S. mutans and S. mitis.

Asunto(s)

RESUMEN

The peptide LYS-[TRP(6)]-Hy-A1 (Lys-a1) is a synthetic derivative of the peptide Hy-A1, initially isolated from the frog species Hypsiboas albopunctatus. According to previous research, it is a molecule with broad antimicrobial activity. The objective of this study was to evaluate the antimicrobial activity of the synthetic peptide Lys-a1 (KIFGAIWPLALGALKNLIK-NH2) on the planktonic and biofilm growth of oral bacteria. The methods used to evaluate antimicrobial activity include the following: determination of the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) in microtiter plates for growth in suspension and quantification of biomass by crystal violet staining and counting of colony forming units for biofilm growth. The microorganisms Streptococcus oralis, Streptococcus sanguinis, Streptococcus parasanguinis, Streptococcus salivarius, Streptococcus mutans and Streptococcus sobrinus were grown in Brain Heart Infusion broth at 37°C under atmospheric pressure with 10% CO2. The peptide was solubilized in 0.1% acetic acid (v/v) at various concentrations (500-1.9 µg mL(-1)). Chlorhexidine gluconate 0.12% was used as the positive control, and BHI culture medium was used as the negative control. The tested peptide demonstrated a remarkable antimicrobial effect, inhibiting the planktonic and biofilm growth of all strains tested, even at low concentrations. Thus, the peptide Lys-a1 is an important source for potential antimicrobial agents, especially for the control and prevention of microbial biofilms, which is one of the most important factors in cariogenic processes.

Asunto(s)

RESUMEN

Aim: The present study aimed to analyze the stress distribution in the dentoalveolar structures of a maxillary central incisor submitted to two situations of impact loading. Materials and Methods: The following loading forces were applied using a three-dimensional finite element model: a force of 500 N at an angle of 45° on the buccal surface of the crown and a 2000 N force acting in the same direction and surface of the tooth. Results: Harmful stress was observed in the second situation, suggesting damage to both the tooth and adjacent tissue. However, the damage found in soft tissues such as dental pulp, was negligible. Conclusion: Injuries resulting from the traumatic situations were more damaging to the integrity of the tooth and its associated hard-tissue structures.

Asunto(s)

RESUMEN

Lectins are a structurally heterogeneous group of proteins that have specific binding sites for carbohydrates and glycoconjugates. Because of their biotechnological potential, lectins are widely used in biomedical research. The present study aimed to evaluate the healing potential of the lectin isolated from the marine red alga Bryothamnion seaforthii (BSL). The lectin was purified using ion exchange chromatography with DEAE cellulose and characterized using tandem mass spectrometry. For healing tests, skin wounds were induced in the dorsal thoracic region of mice. These animals were randomly divided into three groups and subjected to topical treatment for 12 days with BSL, bovine serum albumin and 150 mM NaCl. To evaluate the potential of each treatment, the animals were anesthetized and sacrificed on days 2, 7 and 12, respectively. The parameters evaluated included the wound area, the proportion of wound closure and the histological diagnosis. The wound closure was more effective with BSL (Postoperative Day 7 and 12) than controls. The luminal epithelium was completely restructured; the presence of collagen in the dermis and the strongly active presence of young skin annexes demonstrate the potential of treatment with BSL compared with controls. Our findings suggest that BSL has pro-healing properties and can be a potential medical process in the treatment of acute wounds.

Asunto(s)

RESUMEN

Antimicrobial peptides, molecules produced in many different organisms, have high biocidal activity against several microorganisms. However, several questions about these molecules remain unclear. Therefore, this report details a systematic survey of the literature on the use of antimicrobial peptides against oral pathogens and indicates which peptides and microorganisms are most extensively studied. Articles were located using the PubMed and Science Direct databases with the following inclusion criteria: publication date between 2002 and 2011; keywords "biofilm OR biological film OR biological layer OR bacterial growth" AND "peptide" AND "oral cavity OR mouth OR buccal mucosa OR oral mucosa OR mouth mucosa"; and abstract in English. A total of 73 articles were selected after refinement of the data. An increase in publications focusing on the use of antimicrobial peptides against oral microorganisms was observed. In addition, the peptides produced by cells of the oral mucosa (defensins, LL-37 and histatins) as well as Streptococcus mutans (among cariogenic bacteria) and Porphyromonas gingivalis (among periodontal bacteria) were the most studied subjects. It was concluded that the use of antimicrobial peptides as a tool for microbial control is of increasing importance, likely due to its widespread use, mechanism of action, and low rates of bacterial resistance.

Asunto(s)