Endometritis por Actinomyces en una adolescente: a propósito de un caso / Actinomyces endometritis in an adolescent girl: a case report

La actinomicosis pélvica es una infección poco común del tracto genital inferior y la pelvis. La especie causal más frecuente es la bacteria Actinomyces israelii, y se debe sospechar en toda paciente que presente dolor crónico pélvico y hemorragia uterina. Aunque se manifiesta excepcionalmente en mujeres sin antecedentes de portar dispositivos intrauterinos, es importante considerarla como diagnóstico. Se presenta el caso clínico de una paciente de 12 años con hemorragia uterina anormal resistente al tratamiento, que requirió intervención quirúrgica, incluyendo biopsia endometrial. El diagnóstico resultante fue actinomicosis endometrial. Este caso aporta la actualización del conocimiento sobre esta rara enfermedad y su presentación poco frecuente en adolescentes(AU)

Pelvic actinomycosis is a rare infection of the lower genital tract and pelvis. The most common causative species is the bacterium Actinomyces israelii, and it should be suspected in any patient who presents with chronic pelvic pain and uterine bleeding. Although it occurs exceptionally in women without a history of carrying intrauterine devices, it is important to consider it as a diagnosis. It is presented the clinical case of a 12-year-old patient with abnormal uterine bleeding resistant to treatment, which required surgical intervention, including endometrial biopsy. The resulting diagnosis was endometrial actinomycosis. This case contributes to updating knowledge about this rare disease and its uncommon presentation in adolescents(AU)

Increased IL-12p70 and IL-8 Produced by Monocytes in Response to Streptococcus spp. and Actinomyces spp. Causals of Endodontic Primary Infections.

We sought to evaluate the effect of endodontic-causative microorganisms of primary infections on mononuclear cells such as CD14+, CD4+, CD8+, CD19+ and Tregs Foxp3+. Facultative anaerobic microorganisms were isolated from radicular conducts and peripheral blood samples, which were taken from patients with primary infections. Cellular cultures were performed with peripheral blood mononuclear cells (PBMC) with and without Actinomyces spp. and Streptococcus spp. during 48, 72, and 96 h of contact in culture (concentration 5 × 105 cells/well) in a round plate bound with 48 wells. Later, PBMC was collected for analysis by flow cytometry, with the monoclonal antibodies αCD14, αCD4, αCD8, αCD19 and αFoxp3, and acquired using an FACSCanto II cytometer. The supernatant of cellular cultures was analyzed for the quantification of inflammatory cytokines. Data analysis was performed in FlowJo v10.8.2 and FCAPArray software, and statistical analysis was performed using GraphPad v5.0. software. We observed an increase in the percentage of CD14+ cells in patients at different hours of cellular culture in the presence of both Actinomyces spp. and Streptococcus spp. microorganisms, compared to healthy controls. This study demonstrates the role played by the innate immune system in the pathogeny of endodontic primary infections, explaining the effects that generate the more common microorganisms in this oral pathology.

Antibiotics from rare actinomycetes, beyond the genus Streptomyces.

Throughout the golden age of antibiotic discovery, Streptomyces have been unsurpassed for their ability to produce bioactive metabolites. Yet, this success has been hampered by rediscovery. As we enter a new stage of biodiscovery, omics data and existing scientific repositories can enable informed choices on the biodiversity that may yield novel antibiotics. Here, we focus on the chemical potential of rare actinomycetes, defined as bacteria within the order Actinomycetales, but not belonging to the genus Streptomyces. They are named as such due to their less-frequent isolation under standard laboratory practices, yet there is increasing evidence to suggest these biologically diverse genera harbour considerable biosynthetic and chemical diversity. In this review, we focus on examples of successful isolation and genera that have been the focus of more concentrated biodiscovery efforts, we survey the representation of rare actinomycete taxa, compared with Streptomyces, across natural product data repositories in addition to its biosynthetic potential. This is followed by an overview of clinically useful drugs produced by rare actinomycetes and considerations for future biodiscovery efforts. There is much to learn about these underexplored taxa, and mounting evidence suggests that they are a fruitful avenue for the discovery of novel antimicrobials.

[Actinomyces europaeus (Gleimia europaea) associated with brain abscess: A report of three cases]. / Actinomyces europaeus (Gleimia europaea) asociado con absceso cerebral: comunicación de tres casos.

A brain abscess is a focal infection characterized by a collection of pus in the brain parenchyma. It is a life-threatening condition that should be diagnosed and treated as soon as possible. We report here three cases of patients with otogenic brain abscesses of polymicrobial origin that had in common the isolation of Actinomyces europaeus, which has not been previously described in this location. A. europaeus was identified by the conventional methodology, matrix-associated laser deionization-time of flight mass spectrometry (MALDI-TOF MS) and 16S rRNA gene sequencing. Antibiotic susceptibility was evaluated by the epsilometric method, and all isolates showed sensitivity to penicillin, vancomycin and linezolid, whereas susceptibility to clindamycin and erythromycin was variable. MALDI-TOF MS identification allowed a quick and reliable species level identification in order to provide a rapid and effective response to avoid treatment delay that could lead to increased morbidity and even mortality.

Atlantic Forest's and Caatinga's semiarid soils and their potential as a source for halothermotolerant actinomycetes and proteolytic enzymes.

Actinomycetes are versatile about their metabolism, displaying high capacity to produce bioactive metabolites. Enzymes from actinomycetes represent new opportunities for industrial applications. However, proteases from actinomycetes are poorly described by literature. Thereby, to verify proteolytic potential of actinomycetes, the present study aimed the investigation of bacterial isolates from Caatinga and Atlantic Forest rhizosphere. Fluorescence resonance energy transfer (FRET) peptide libraries were adopted for the evaluations, since they are faster and more qualitative methods, if compared with others described by most reports. A total of 52 microorganisms were inoculated in different culture media (PMB, potato dextrose agar, brain heart infusion agar, Starch Casein Agar and Reasoner's 2A agar), temperatures (12, 20, 30, 37, 45 and 60°C), and saline conditions (0-4 M NaCl), during 7 days. The actinomycetes named as AC 01, 02 and 52 were selected and showed enzymatic abilities under the peptide probes Abz-KLRSSKQ-EDDnp and Abz-KLYSSKQ-EDDnp, achieving enhanced performance at 30 °C. Biochemical parameters were established, showing a predominance of alkaline proteases with activity under saline conditions. Secreted proteases hydrolysed preferentially polar uncharged residues (Y and N) and positively charged groups (R). Phenylmethylsulfonyl fluoride and ethylenediaminetetraacetic acid inhibited the proteins, a characteristic of serine (AC 01 e 02) and metalloproteases (AC 52). All selected strains belonged to Streptomyces genera. In summary, actinomycete strains with halophilic proteolytic abilities were selected, which improve possibilities for their use in detergent formulations, food processing, waste management and industrial bioconversion. It is important to highlight that this is the first report using FRET libraries for proteolytic screening from Caatinga and Atlantic Forest actinobacteria.

Biosynthesis of silver nanoparticles using actinomycetes, phytotoxicity on rice seeds, and potential application in the biocontrol of phytopathogens.

To find effective silver nanoparticles (AgNPs) for control of phytopathogens, in this study, two strains of actinomycetes isolated from the soil of the Brazilian biome Caatinga (Caat5-35) and from mangrove sediment (Canv1-58) were utilized. The strains were identified by using the 16S rRNA gene sequencing as Streptomyces sp., related to Streptomyces mimosus species. The obtained AgNPs were coded as AgNPs 35 and AgNPs58 and characterized by size and morphology using dynamic light scattering, zeta potential, transmission electron microscopy, and Fourier transformed infrared (FTIR). The antifungal activity of the AgNPs35 and AgNPs58 was evaluated in vitro by the minimal inhibitory concentration (MIC) assay on the phytopathogens, Alternaria solani, Alternaria alternata, and Colletotrichum gloeosporioides. The phytotoxic effect was evaluated by the germination rate and seedling growth of rice (Oryza sativa). AgNPs35 and AgNPs58 showed surface plasmon resonance and average sizes of 30 and 60 nm, respectively. Both AgNPs presented spherical shape and the FTIR analysis confirmed the presence of functional groups such as free amines and hydroxyls of biomolecules bounded to the external layer of the nanoparticles. Both AgNPs inhibited the growth of the three phytopathogens tested, and A. alternate was the most sensible (MIC ≤ 4 µM). Moreover, the AgNPs35 and AgNPs58 did not induce phytotoxic effects on the germination and development of rice seedlings. In conclusion, these AgNPs are promising candidates to biocontrol of these phytopathogens without endangering rice plants.

Overexpression of proinflammatory cytokines in dental pulp tissue and distinct bacterial microbiota in carious teeth of Mexican Individuals.

The prevalence of dental caries in the Mexican adult population aged 20 to 85 years is around 93.3%, and 50% in Mexican children and adolescents. Worldwide, it is the most common non-communicable disease. One of the main etiological factors for dental caries is the oral microbiome and changes in its structure and function, with an expansion of pathogenic bacteria like Streptococcus mutans. The exposed dental pulp tissue triggers an innate immune response to counteract this bacterial invasion. The relation between oral dysbiosis and innate immune responses remains unclear. We aimed to understand the relationship between innate immune response and the oral microbiota by quantifying the expression of Toll-like receptors (TLRs) and proinflammatory markers (cytokines and a chemokine) in dental pulp tissue, either exposed or not to carious dentin, and to correlate this information with the oral microbiome found in healthy teeth and those with moderate caries. RNA was purified from pulp tissue, subjected to RT-qPCR and analysed with the ΔΔCt method. Supragingival dental plaque of non-carious teeth and dentin of carious teeth were subjected to 16S targeted sequencing. Principal coordinate analysis, permutational multivariate ANOVA, and linear discriminant analysis were used to assess differences between non-carious and carious teeth. Correlations were assessed with Spearman´s test and corrected for multiple comparisons using the FDR method. The relative abundance (RA) of Lactobacillus, Actinomyces, Prevotella, and Mitsuokella was increased in carious teeth; while the RA of Haemophilus and Porphyromonas decreased. Olsenella and Parascardovia were only detected in carious teeth. Significant overexpression of interleukin 1 beta (IL1 ß), IL6, and CXCL8 was detected in pulp tissue exposed to carious dentin. IL1ß correlated positively with TLR2 and Actinomyces; yet negatively with Porphyromonas. These findings suggest that immune response of pulp tissue chronically exposed to cariogenic microbiome is triggered by proinflammatory cytokines IL1ß and IL6 and the chemokine CXCL8.

Isolation and characterization of Buchananella hordeovulneris from feline pyothorax.

A 1-year-old female mixed-breed cat was admitted to a veterinary hospital in Southern Brazil with tachypnea, low thoracic amplitude, restrictive breathing pattern, and cyanotic mucous membranes 2 days after elective castration surgery. Radiography revealed pleural effusion, and approximately 100-200 mL of fluid was collected by thoracocentesis. The reddish purulent exudate contained large numbers of yellowish-white granules with branched filamentous structures on cytological examination. The fluid was plated on blood agar and incubated under aerobiosis at 37 °C. On the third day of incubation, circular, dry, and opaque colonies, measuring < 0.5 mm in diameter, were observed. Their phenotypic and molecular characteristics were compatible with Buchananella hordeovulneris (basonym: Actinomyces hordeovulneris), a pathogenic actinomycete rarely detected in cats. Our findings indicate that B. hordeovulneris should be included in the differential diagnosis of pyothorax in cats together with Actinomyces spp. and Nocardia spp. Taxonomic confirmation of disease-causing microorganisms in animals is important to understand the course of infection and its association with disease epidemiology.

Rhodococcus: A promising genus of actinomycetes for the bioremediation of organic and inorganic contaminants.

Rhodococcus is a genus of actinomycetes that has been explored by the scientific community for different purposes, especially for bioremediation uses. However, the mechanisms governing Rhodococcus-mediated bioremediation processes are far from being fully elucidated. In this sense, this work aimed to compile the recent advances in the use of Rhodococcus for the bioremediation of organic and inorganic contaminants present in different environmental compartments. We reviewed the bioremediation capacity and mechanisms of Rhodococcus spp. in the treatment of polycyclic aromatic hydrocarbons, phenolic substances, emerging contaminants, heavy metals, and dyes given their human health risks and environmental concern. Different bioremediation techniques were discussed, including experimental conditions, treatment efficiencies, mechanisms, and degradation pathways. The use of Rhodococcus strains in the bioremediation of several compounds is a promising approach due to their features, primarily the presence of appropriate enzyme systems, which result in high decontamination efficiencies; but that vary according to experimental conditions. Besides, the genus Rhodococcus contains a small number of opportunistic species and pathogens, representing an advantage from the point of view of safety. Advances in analytical detection techniques and Molecular Biology have been collaborating to improve the understanding of the mechanisms and pathways involved in bioremediation processes. In the context of using Rhodococcus spp. as bioremediation agents, there is a need for more studies that 1) evaluate the role of these actinomycetes on a pilot and field scale; 2) use genetic engineering tools and consortia with other microorganisms to improve the bioremediation efficiency; and 3) isolate new Rhodococcus strains from environments with extreme and/or contaminated conditions aiming to explore their adaptive capabilities for bioremediation purposes.

A Rare Case of Non-IUD-Related Chronic Endometritis caused by Actinomyces Bacteria in a Postmenopausal Woman: A Case Report.

Pelvic actinomycosis is a rare condition, usually associated with intrauterine device (IUD) use. Its clinical presentation may vary from being asymptomatic to the mimicking of pelvic malignancy; it has been described as one of the most misdiagnosed diseases. A 78-year-old woman without a history of IUD use, arrived at our clinic complaining of chronic and intermittent postmenopausal bleeding associated with lower pelvic pain. An endometrial curettage was performed, and endometritis (caused by Actinomyces) identified. Treatment with intravenous piperacillin and tazobactam for 7 days, followed by 6 weeks of oral ampicillin, daily, decreased the bleeding and the pain. Although rare, it is important to consider Actinomyces-related endometritis as a differential diagnosis in cases of elderly woman with postmenopausal bleeding and without a history of IUD use.

Antagonist activities and phylogenetic relationships of actinomycetes isolated from an Artemisia habitat.

Diverse habitats have been screened for novel antimicrobial actinomycetes, while others remain unexplored. In this study, we analyzed the bioactivities of actinomycetes cultured from rhizosphere soils of the desert plant Artemisia tridentata and the nearby bulk soils. Actinomycetes were screened for antifungal and antibacterial activities toward a panel of plant pathogens; all comparisons were between activities of rhizosphere soil isolates toward those of its counterpart bulk soil. A selected group of the strongest antifungal isolates were also tested against two antifungal-drug resistant strains of Candida albicans. 16S rDNA partial sequences and phylogenetic analysis of isolates that showed broad-spectrum antifungal activities were performed. Forty-two out of 200 and two soil isolated actinomycetes were selected for their strong antifungal activities. The highest proportion of isolates (p<0.05) from rhizosphere soil of an old plant showed antagonism against gram-positive bacteria (0.483 and 0.224 proportions against Bacillus subtilis and Rathayibacter tritici, respectively), and phytopathogenic fungi (0.259, 0.431, and 0.345 proportions against Fusarium oxysporum, Rhizoctonia solani and Pythium ultimum, respectively), while the highest antagonism against the gram-negative bacteria predominated in isolates from the bulk soils. Isolates from a rhizosphere soil of a young plant were characterized for strong antagonist activities against Fusarium oxysporum (0.333 proportion, p<0.05). Phylogenetic analysis of 16S rDNA sequences showed that isolates that exhibited strong antifungal activity were genetically similar. We conclude that the rhizosphere soil of A. tridentata is an excellent source for discovery of actinomycetes with potentially novel antifungal compounds.

Estudio de la actividad antimicrobiana de Xenophyllum poposum sobre microorganismos de la cavidad bucal por el método de difusión radial / Study of the antimicrobial activity of Xenophyllum poposum on microorganisms of the oral cavity by the radial diffusion method

Resumen En este estudio se evaluó la actividad antimicrobiana in vitro de extractos de Xenophyllum poposum sobre microorganismos bucales como Streptococcus mutans, Streptococcus sobrinus, Lactobacillus casei, Actinomyces naeslundii, Actinomyces odontolyticus, Candida albicans y Veillonella sp. Se empleó el método de difusión radial en agar y como controles negativo y positivo de inhibición se emplearon etanol y clorhexidina al 0,12% (Plac out NF®) respectivamente. Los extractos con mayor actividad antimicrobiana fueron el etanólico y el clorofórmico. La diferencia entre ambos no fue estadísticamente significativa (p≥0,05). Tampoco se observó diferencia significativa con respecto a la clorhexidina, excepto sobre Veillonella sp., ya que el extracto etanólico presentó halos de inhibición significativamente menores sobre este microorganismo. Esto es importante ya que Veillonella se considera indicador de salud en relación a la caries dental. En base a esto, el extracto etanólico de Xenophyllum poposum podría ser usado como control químico de la biopelícula dental.

Abstract In this study, the in vitro antimicrobial activity of Xenophyllum poposum extracts on oral microorganisms such as Streptococcus mutans, Streptococcus sobrinus, Lactobacillus casei, Actinomyces naeslundii, Actinomyces odontolyticus, Candida albicans, Veillonella sp. was evaluated. The radial diffusion method in agar was used and 0.12% ethanol and chlorhexidine (Plac out NF®) were used as negative and positive inhibition controls, respectively. The extracts with the highest antimicrobial activity were the ethanolic and chloroform extracts. The difference between the two was not statistically significant (p≥0.05). No significant difference was observed with respect to chlorhexidine, except on Veillonella sp., since the ethanolic extract presented significantly lower inhibition halos on this microorganism. This is important as Veillonella is considered an indicator of health in relation to dental caries. Based on this, the ethanolic extract of Xenophyllum poposum could be used as chemical control of dental biofilm.

Resumo Neste estudo, a atividade antimicrobiana de extratos de Xenophyllum poposum sobre microrganismos orais como Streptococcus mutans, Streptococcus sobrinus, Lactobacillus casei, Actinomyces naeslundii, Actinomyces odontolyticus, Candida albicans e Veillonella sp. Foi utilizado o método de difusão radial em ágar e etanol 0,12% e clorexidina (Plac out NF®) como controles de inibição negativa e positiva, respectivamente. Os extratos com maior atividade antimicrobiana foram os extratos etanólico e clorofórmio. A diferença entre os dois não foi estatisticamente significativa (p≥0,05). Não foi observada diferença significativa em relação à clorexidina 0,12%, exceto em Veillonella sp., uma vez que o extrato etanólico apresentou halos de inibição significativamente menores neste microrganismo. Isso é importante, pois a Veillonella é considerada um indicador de saúde em relação à cárie dentária. Com base nisso, o extrato etanólico de Xenophyllum poposum pode ser utilizado como controle químico do biofilme dental.

Infecciones abdominales por Actinomyces odontolyticus: comunicación de dos casos / Abdominal infections due Actinomyces odontolyticus: a report of two cases

Resumen Actinomyces spp es una familia de bacilos grampositivos saprofíticos que rara vez producen infecciones en el ser humano. Actinomyces odontolyticus forma parte de la microbiota oral y existen escasos reportes de casos de infecciones asociadas a este microorganismo, principalmente de localización oral, torácica, pélvica y bacteremias. Estas infecciones se caracterizan por ser recidivantes y causar abscesos y trayectos fistulosos. Su aislamiento microbiológico es difícil ya que la mayoría de los equipos automatizados no identifican la especie de Actinomyces, por lo que técnicas como MALDI-TOF MS resulta de gran ayuda en el diagnóstico definitivo. Finalmente, el tratamiento antibacteriano debe ser prolongado, acompañado del drenaje quirúrgico de las colecciones. Presentamos dos casos de infección abdominal recurrente por A. odontolyticus, en pacientes inmunocompetentes, con tratamiento exitoso.

Abstract Actinomyces spp is a family of saprophytic gram-positive rods that rarely cause infections in humans. Actinomyces odontolyticus is part of the oral microbiota and there are few case reports of infections associated, mainly oral, thoracic, pelvic involvement and bacteremia. These infections are characterized by being recurrent and causing abscesses and fistulous tracts. Microbiological isolation of the microorganism is difficult because most of the automated identification equipment does not detect the Actinomyces species. The use of identification techniques such as MALDI-TOF MS is a great help in the definitive diagnosis. Finally, antibacterial treatment should be prolonged, and accompanied by surgical drainage of the collections. We report two cases of recurrent abdominal infection by A. odontolyticus, in immunocompetent patients, with successful treatment.

Efeito antimicrobiano e anti-inflamatório de ácidos fenólicos isolados, combinados e incorporados em hidrogéis de quitosana para aplicação endodôntica / Antimicrobial and anti-inflammatory effect of phenolic acids, alone, combined and incorporated in chitosan hydrogels for endodontic application

O objetivo do tratamento endodôntico é manter a integridade da raiz, bem como, prevenir ou resolver doenças periapicais, pela erradicação dos microrganismos e de suas fontes de nutrientes provenientes do sistema de canais radiculares. A complexidade da anatomia dos canais radiculares e dos biofilmes multiespécies aumenta a dificuldade em eliminar os microrganismos e controlar a inflamação por procedimentos químico-mecânicos convencionais, o que justifica o uso de medicações intracanais. Novos compostos com amplo efeito antimicrobiano e potencial antiinflamatório, como os ácidos fenólicos, poderiam ser explorados como princípios ativos de medicamentos intracanais. Entretanto, para aumentar a solubilidade, controlar a liberação e estender os efeitos biológicos dos ácidos fenólicos, seria interessante incorporá-los em carreadores de medicamentos como os hidrogéis de quitosana. Este estudo foi dividido em dois capítulos que apresentaram como objetivos: 1) avaliar as atividades antimicrobiana, antibiofilme e antiinflamatória e a citotoxicidade do ácido cinâmico e seus derivados; 2) sintetizar e caracterizar as propriedades químicas e físico-mecânicas de hidrogéis termossensíveis de quitosana e poloxamer contendo ácidos fenólicos, e avaliar o efeito desses hidrogéis sobre biofilmes multiespécies e na viabilidade de macrófagos e fibroblastos. No capítulo 1, a atividade antimicrobiana do ácido cinâmico (CI) e seus derivados ácido cumárico (CO), ácido cafeico (CA), ácido ferúlico (FE) e ácido sinápico (SI) foi avaliada pela determinação da concentração inibitória e bactericida mínima (CIM/CBM) e Concentração Inibitória Fracionada (CIF) sobre Enterococcus faecalis, Streptococcus mutans, Lactobacillus casei, Actinomyces israelii e Fusobacterium nucleatum. Os ácidos fenólicos foram selecionados e seu efeito em biofilmes dual-espécies e multiespécies com as mesmas cepas padrão ou cepas clínicas foram avaliados por contagem bacteriana, microscopia eletrônica de varredura e microscopia confocal. A viabilidade de fibroblastos L929 e macrófagos RAW 264.7 na presença desses ácidos fenólicos foi avaliada por ensaios de resazurina. Além disso, os níveis de mRNA dos marcadores pró-inflamatórios TNF-α, IL-1ß, iNOS e COX-2 foram determinados por PCR quantitativo TaqMan após exposição de macrófagos aos ácidos fenólicos e ao lipopolissacarídeo (LPS). No capítulo 2, foi realizada a síntese e caracterização físicomecânica de hidrogéis de quitosana-poloxamer (CPH) contendo ácidos fenólicos e avaliado seus efeitos no biofilme multiespécies e na viabilidade de macrófagos e fibroblastos. Os dados foram analisados estatisticamente considerando p< 0,05. O ácido cinâmico e o ácido cafeico apresentaram efeito inibitório e bactericida contra todas as espécies bacterianas testadas, com os menores valores de CIM e CBM. Entretanto, não houve efeito sinérgico entre eles (FICI> 0,5). Ambos os compostos (5x a CIM mais alta) foram eficazes na eliminação de biofilmes dual-espécies e na redução significativa de biofilmes multiespécies, especialmente o ácido cinâmico. O ácido cinâmico causou toxicidade mínima para ambas as culturas celulares nas concentrações de CIM e o ácido cafeico não foi citotóxico em concentrações abaixo de 0,125 mg/mL. Ambos os compostos reduziram significativamente TNF-α, IL-1ß, iNOS e COX-2, de maneira dose-dependente. Os CPH foram caracterizados como termorreversíveis e com propriedades mecânicas e bioadesivas desejáveis. O efeito dos hidrogéis CPH+CA (77,8%) e CPH+CI (73,2%) em reduzir os biofilmes multiespécies foi superior ao CPH+ hidroxido de cálcio (CH) (53,6%) e CPH+ clorexidina (CHX) (39,9%). Em geral, CPH + CI causou menor citotoxicidade quando comparado a CPH + CA, para ambas as linhagens celulares. Conclui-se que o ácido cinâmico e ácido cafeico apresentaram efeito bactericida e contra biofilmes formados por bactérias associadas com infecções endodônticas, causando baixa citotoxicidade. Ambos os compostos apresentaram efeito antiinflamatório, inibindo a expressão de marcadores próinflamatórios em macrófagos estimulados por LPS. Os hidrogéis de quitosana-poloxamer foram termorreversíveis e apresentaram adequadas propriedades mecânicas e adesivas para aplicação clínica, e quando combinados principalmente com ácido cinâmico, promoveram a redução de biofilmes multiespécies formados nos túbulos dentinários, causando baixa toxicidade em fibroblastos e macrófagos(AU)

The objective of endodontic treatment is to maintain the integrity of the root, as well as to prevent or resolve periapical diseases, by eradicating microorganisms and their sources of nutrients from the root canal system. The complexity of root canal anatomy and multispecies biofilms increases the difficulty in eliminating microorganisms and controlling inflammation by conventional chemical-mechanical procedures, which justifies the use of intracanal medications. New compounds with broad antimicrobial effect and anti-inflammatory potential, such as phenolic acids, could be explored as active principles of intracanal medications. However, to increase the solubility, control the release and extend the biological effects of phenolic acids, it would be interesting to incorporate them into drug carriers such as chitosan hydrogels. This study was divided into two chapters with the following objectives: 1) to evaluate the antimicrobial, antibiofilm and anti-inflammatory activities and the cytotoxicity of cinnamic acid and its derivatives; 2) synthesize and characterize chemical and physicomecanical properties of thermosensitive chitosan and poloxamer hydrogels containing phenolic acids and evaluate the effect of these hydrogels on multispecies biofilms and on the viability of macrophages and fibroblasts. In chapter 1, the antimicrobial activity of cinnamic acid (CI) and its derivatives coumaric acid (CO), caffeic acid (CA), ferulic acid (FE) and sinapic acid (SI) was evaluated by determining the minimum inhibitory and bactericidal concentration (MIC/MBC) and Fractional Inhibitory Concentration (FIC) on Enterococcus faecalis, Streptococcus mutans, Lactobacillus casei, Actinomyces israelii and Fusobacterium nucleatum. Phenolic acids were selected and their effect on bispecies and multispecies biofilms with the same standard or clinical strains were evaluated by bacterial counts, scanning electron microscopy and confocal microscopy. The viability of L929 fibroblasts and RAW 264.7 macrophages in the presence of these phenolic acids was evaluated by resazurin assays. In addition, mRNA levels of the proinflammatory markers TNF-α, IL-1ß, iNOS and COX-2 were determined by quantitative TaqMan PCR after macrophage exposure to phenolic acids and lipopolysaccharide (LPS). In chapter 2, the synthesis and physical-mechanical characterization of chitosanpoloxamer (CPH) hydrogels containing phenolic acids were performed and their effects on multispecies biofilm and on the viability of macrophages and fibroblasts were evaluated. Data were statistically analyzed considering p< 0.05. Cinnamic acid and caffeic acid showed an inhibitory and bactericidal effect against all bacterial species tested, with the lowest MIC and MBC values. However, no synergistic effect was observed between the compounds (FICI> 0.5). Both compounds (at 5x the highest MIC) were effective in eliminating dual-species biofilms and significantly decreasing multispecies biofilms, especially cinnamic acid. Cinnamic acid caused minimal toxicity to both cell cultures at MIC concentrations and caffeic acid was not cytotoxic at concentrations below 0.125 mg/mL. Both compounds significantly reduced TNF-α, IL1ß, iNOS and COX-2, in a dose-dependent manner. CPH were characterized as thermoreversible and with adequate mechanical and bioadhesive properties. The effect of CPH+CA (77.8%) and CPH+CI (73.2%) hydrogels against multispecies biofilms was superior to CPH + calcium hydroxide (CH) (53.6%) and CPH + chlorhexidine (CHX) (39.9%). In general, CPH + CI caused less cytotoxicity when compared to CPH + CA, for both cell lines. In conclusion, cinnamic acid and caffeic acid showed bactericidal effect and against biofilms of bacteria associated with endodontic infections, causing minimal cytotoxicity. In addition, both compounds showed an anti-inflammatory effect, inhibiting the expression of pro-inflammatory markers in LPS-stimulated macrophages. The chitosan-poloxamer hydrogels were thermoreversible and presented adequate mechanical and bioadhesive properties for clinical application, and when combined specially with cinnamic acid, they promoted the reduction of multispecies biofilms formed in the dentinal tubules, causing low toxicity to fibroblasts and macrophages(AU)

Absceso cerebral por Actinomyces sp: una infección infrecuente en niños: a propósito de un casot / Actinomyces sp. brain abscess: a rare infection in children: a case repor

A pesar de los avances en las técnicas de diagnóstico y tratamiento, las infecciones intracraneanas son aún enfermedades graves con una incidencia estimada entre 0,3 y 1,3 casos por cada 100 000 habitantes. Se presenta un paciente previamente sano con un absceso cerebral de diagnóstico intraoperatorio en quien, si bien el cultivo evidenció desarrollo polimicrobiano, se identificó presuntivamente Actinomyces sp. en la anatomía patológica. Dado este hallazgo, se realizó antibioticoterapia combinada prolongada con buena evolución. La presentación de este proceso supurado fue inespecífica y la contribución de la anatomía patológica en el diagnóstico etiológico fue relevante. La identificación de un microorganismo inhabitual definió la necesidad de profundizar en la determinación de factores predisponentes

Despite advances in diagnostic and treatment techniques, intracranial infections remain serious diseases with an estimated incidence of between 0.3 and 1.3 cases/100,000 inhabitants. We present a previously healthy patient with an intraoperative diagnostic of brain abscess, in whom although the culture showed polymicrobial development, Actinomyces sp was presumptively identified in the pathological anatomy. Given this finding, prolonged combined antibiotic therapy was performed with good evolution The presentation of this suppurative process was nonspecific and the contribution of the anatomopathology in the etiological diagnosis was relevant. The identification of an unusual microorganism defined the need to deepen the identification of predisposing factors.

[Actinomyces sp. brain abscess: a rare infection in children. A case report]. / Absceso cerebral por Actinomyces sp.: una infección infrecuente en niños. A propósito de un caso.

Despite advances in diagnostic and treatment techniques, intracranial infections remain serious diseases with an estimated incidence of between 0.3 and 1.3 cases/100,000 inhabitants. We present a previously healthy patient with an intraoperative diagnostic of brain abscess, in whom although the culture showed polymicrobial development, Actinomyces sp was presumptively identified in the pathological anatomy. Given this finding, prolonged combined antibiotic therapy was performed with good evolution. Absceso cerebral por Actinomyces sp.: una infección infrecuente en niños. A propósito de un caso Actinomyces sp. brain abscess: a rare infection in children. A case report The presentation of this suppurative process was nonspecific and the contribution of the anatomopathology in the etiological diagnosis was relevant. The identification of an unusual microorganism defined the need to deepen the identification of predisposing factors.

A pesar de los avances en las técnicas de diagnóstico y tratamiento, las infecciones intracraneanas son aún enfermedades graves con una incidencia estimada entre 0,3 y 1,3 casos por cada 100 000 habitantes. Se presenta un paciente previamente sano con un absceso cerebral de diagnóstico intraoperatorio en quien, si bien el cultivo evidenció desarrollo polimicrobiano, se identificó presuntivamente Actinomyces sp. en la anatomía patológica. Dado este hallazgo, se realizó antibioticoterapia combinada prolongada con buena evolución. La presentación de este proceso supurado fue inespecífica y la contribución de la anatomía patológica en el diagnóstico etiológico fue relevante. La identificación de un microorganismo inhabitual definió la necesidad de profundizar en la determinación de factores predisponentes.

Integrating perspectives in actinomycete research: an ActinoBase review of 2020-21.

Last year ActinoBase, a Wiki-style initiative supported by the UK Microbiology Society, published a review highlighting the research of particular interest to the actinomycete community. Here, we present the second ActinoBase review showcasing selected reports published in 2020 and early 2021, integrating perspectives in the actinomycete field. Actinomycetes are well-known for their unsurpassed ability to produce specialised metabolites, of which many are used as therapeutic agents with antibacterial, antifungal, or immunosuppressive activities. Much research is carried out to understand the purpose of these metabolites in the environment, either within communities or in host interactions. Moreover, many efforts have been placed in developing computational tools to handle big data, simplify experimental design, and find new biosynthetic gene cluster prioritisation strategies. Alongside, synthetic biology has provided advances in tools to elucidate the biosynthesis of these metabolites. Additionally, there are still mysteries to be uncovered in understanding the fundamentals of filamentous actinomycetes' developmental cycle and regulation of their metabolism. This review focuses on research using integrative methodologies and approaches to understand the bigger picture of actinomycete biology, covering four research areas: i) technology and methodology; ii) specialised metabolites; iii) development and regulation; and iv) ecology and host interactions.

Cytocompatibility and Synergy of EGCG and Cationic Peptides Against Bacteria Related to Endodontic Infections, in Planktonic and Biofilm Conditions.

This study evaluated the cytocompatibility and antimicrobial/antibiofilm effects of epigallocatechin-3-gallate (EGCG) associated with peptide LL-37 and its analogue KR-12-a5 against oral pathogens. The effect of the compounds on metabolism of fibroblasts was evaluated by methyltetrazolium assays. Antimicrobial activity of the compounds was evaluated on Streptococcus mutans, Enterococcus faecalis, Actinomyces israelii, and Fusobacterium nucleatum under planktonic conditions, on single- and dual-species biofilms and E. faecalis biofilms in dentinal tubules and analyzed by bacterial counts and confocal microscopy. Data were statistically analyzed considering p < 0.05. EGCG and peptide combinations were not toxic to fibroblasts. KR-12-a5 showed synergistic or addictive effects with EGCG and LL-37 against all bacteria tested. However, EGCG associated with KR-12-a5 demonstrated the highest bactericidal activity on all bacteria tested, at lower concentrations. In single-species biofilms, EGCG + KR-12-a5 eliminated S. mutans and A. israelii and reduced E. faecalis and F. nucleatum counts around 5 log CFU/mL. EGCG + KR-12-a5 reduced E. faecalis (-3.93 log CFU/mL) and eliminated S. mutans in dual-species biofilms. No growth of E. faecalis and significant reduction in A. israelii (-6.24 log CFU/mL) and F. nucleatum (-4.62 log CFU/mL) counts were detected in dual-species biofilms. The combination of EGCG and KR-12-a5 led to 88% of E. faecalis dead cells inside dentin tubules. The association of EGCG and KR-12-a5 was cytocompatible and promoted synergistic effect against biofilms of bacteria associated with endodontic infections.

Antibiofilm effects of Thymus vulgaris and Hyptis spicigera essential oils on cariogenic bacteria.

Aim: The inhibitory and antibiofilm effects of Thymus vulgaris (EOTv) and Hyptis spicigera essential oils (EOHs) on cariogenic microorganisms were evaluated. Materials & methods: The chemical characterization of EOTv was performed by gas chromatography/mass spectrometry. Streptococcus mutans, Streptococcus gordonii, Streptococcus sanguinis, Streptococcus mitis, Streptococcus sobrinus, Lactobacillus acidophilus and Actinomyces naeslundii were used for agar diffusion assays and determination of minimal inhibitory and minimal bactericide concentrations. In addition, 20 streptococci and lactobacilli clinical isolates were also tested. The effects of essential oil on microbial initial biofilm formation and on preformed microcosm biofilm formed from human saliva were studied. Results & conclusion: Both essential oils had inhibitory effects on the cariogenic species and reduced the bacterial adherence to dental enamel. Essential oils were able to disrupt preformed microcosm biofilms. Thymus vulgaris and Hyptis spicigera essential oils have potential to be used in the development of formulations to the control of cariogenic biofilms.

[Analysis of the diversity of Actinomyces/Actinotignum clinical isolates in a university hospital]. / Análisis de la diversidad de aislados clínicos de Actinomyces/Actinotignum en un hospital universitario.

Actinomyces and related genera are grampositive bacilli, opportunistic pathogens, which have been mainly involved in endogenous infections. However, due to the complexity in identifying them for most clinical laboratories, there is scant knowledge about their real clinical significance. In this work, 166 isolates of 13 different species of Actinomyces/Actinotignum species recovered from clinical samples of patients treated in a university hospital were studied. The identification was performed by MALDI-TOF MS and molecular identification. MALDI-TOF MS identified 91.57% of the isolates (152/166) at the species level using a score ≥ 1.7 and 3.61% (6/166) of the isolates were identified only at the gender level with a score ≥ 1.5. MALDI-TOF MS did not yield reliable identification results for 4.82% (8/166) of the isolates. Actinomyces/Actinotignum species were isolated from: soft tissue (n: 47), urine samples (n: 35), head / neck abscesses (n: 19), genital abscesses (n: 11), blood samples (n: 10), breast abscesses (n: 8), osteoarticular samples (n: 6), abdominal/ascitic fluids (n: 3), abdominal abscesses (n: 5), sputum/BAL (n: 4), brain abscesses (n: 3), and others (n: 15). The results obtained from the statistical analysis showed a high differential frequency (> 2) for the location/species association: urine/A. schaalii/sanguinis; brain abscesses/A. europaeus; osteoarticular samples/A. urogenitalis; abdominal abscesses/ A. turicensis; respiratory samples/A. naeslundii/viscosus. This information provides a greater understanding of the clinical and epidemiological relevance of these species. The pathogenic role of Actinomyces spp. will be increasingly revealed as these microorganisms could be recognized thanks to prolonged culture and the advances in identification technology facilitated by MALDI-TOF MS.