Episymbiotic Saccharibacteria suppresses gingival inflammation and bone loss in mice through host bacterial modulation.

Saccharibacteria (TM7) are obligate epibionts living on the surface of their host bacteria and are strongly correlated with dysbiotic microbiomes during periodontitis and other inflammatory diseases, suggesting they are putative pathogens. However, due to the recalcitrance of TM7 cultivation, causal research to investigate their role in inflammatory diseases is lacking. Here, we isolated multiple TM7 species on their host bacteria from periodontitis patients. These TM7 species reduce inflammation and consequential bone loss by modulating host bacterial pathogenicity in a mouse ligature-induced periodontitis model. Two host bacterial functions involved in collagen binding and utilization of eukaryotic sialic acid are required for inducing bone loss and are altered by TM7 association. This TM7-mediated downregulation of host bacterial pathogenicity is shown for multiple TM7/host bacteria pairs, suggesting that, in contrast to their suspected pathogenic role, TM7 could protect mammalian hosts from inflammatory damage induced by their host bacteria.

A rare case of Actinomyces skin and soft tissue infection in an end-stage kidney disease patient with a review of the literature.

End-stage kidney disease (ESKD) patients are a commonly overlooked immunocompromised population that places them at risk for rare infections. We describe the case of a 78-year-old man with a history of ESKD managed with thrice weekly in-center hemodialysis who had a prolonged episode of left elbow pain and drainage and was eventually found to have a skin and soft tissue infection from Actinomyces radingae. We review the bacteriology of Actinomyces spp. and the experiences of other providers who have treated actinomycosis in individuals with ESKD. The anatomic sites and demographics of these individuals are heterogeneous, but they all generally require a long antibiotic course with a beta-lactam and portend to a good prognosis. High index of suspicion is needed to identify rare and atypical infections in the ESKD population.

[Actinomycosis]. / Actinomycose.

Actinomycosis is a chronic bacterial infection, caused by the genus Actinomyces, commensal of the digestive and genital tract. The most common presentation of the disease affects the cervicofacial region, but other anatomical sites in the abdomen, thorax and central nervous system may be involved. Differential diagnosis includes neoplasia. Prolonged culture of deep samples in an anaerobic environment is the gold standard of the diagnosis. The treatment of choice is intravenous penicillin G followed by oral amoxicillin for a total duration of 6 to 12 months. However, depending on the location and response to antibiotics, shorter therapy may be considered.

L'actinomycose est une infection bactérienne chronique, causée par le genre Actinomyces, commensal des tractus digestif et génital. La forme la plus fréquente de la maladie touche la région cervico-faciale, mais d'autres sites anatomiques dans l'abdomen, le thorax et le système nerveux central peuvent être concernés. Le diagnostic différentiel se fait souvent avec une néoplasie. La mise en culture prolongée de prélèvements profonds en milieu anaérobe est le gold standard du diagnostic. Le traitement de choix est la pénicilline G intraveineuse, suivi d'un relais per os par amoxicilline, pour une durée totale de 6 à 12 mois. Cependant, selon la localisation et la réponse aux antibiotiques, une thérapie plus courte peut être envisagée.

Pott's puffy tumor por Actinomyces tras trauma craneal leve / Pott's puffy tumor by Actinomyces after minor head trauma

El Pott's puffy tumor (PPT) es una rara entidad que en la actualidad representa un abombamiento del cuero cabelludo asociado a un absceso subperióstico y a una osteomielitis craneal, pudiendo acompañarse o no de infección intracraneal. Suele asociarse a la sinusitis frontal, tratándose de una complicación típica, aunque poco frecuente de la misma. Por su parte las osteomielitis causadas por Actinomyces son raras y suelen tener lugar a nivel mandibular, no encontrándose apenas casos de osteomielitis craneal causada por este género bacteriano, en especial tras traumatismo craneoencefálico. Presentamos un caso especialmente poco usual al tratarse de un PPT frontal tras traumatismo cerrado, con componente intracraneal y en el que tras cirugía se aisló Actinomyces como copartícipe de dicha infección, junto con Fusobacterium y Propionibacterium

Pott's puffy tumour (PPT) is a rare entity that involves scalp swelling associated with subperiosteal abscess and cranial osteomyelitis, occasionally accompanied by intracranial infection. It is usually affiliated with frontal sinusitis, which is a typical but infrequent complication. On the contrary, Osteomyelitis by Actinomyces is rare and usually occurs at the mandibular level, with very few cases of cranial osteomyelitis caused by this bacterial specie, especially after traumatic brain injury. We report an exceptionally unusual case of a PPT frontal tumor after blunt trauma (closed head injury), with an intracranial lesion whereby Actinomyces was isolated after surgery, as a co-participant of the mentioned infection besides Fusobacterium and Propionibacterium

Intrageneric and Intergeneric Interactions Developed by Oral Streptococci: Pivotal Role in the Pathogenesis of Oral Diseases.

Oral streptococci are among the most abundant genera present in the oral cavity. They are usually the first colonizers of oral surfaces and they develop extensive microbial interactions, playing a fundamental role in the pathogenesis of oral diseases such as dental caries and periodontitis. In addition to physical adherence, streptococcal cells also exchange messages with cells from another Streptococcus spp. and other microorganisms in the form of metabolites and signaling molecules. In this review, we focused on these intrageneric and intergeneric interactions, and their association with oral diseases.

Liquid-Infused Structured Titanium Surfaces: Antiadhesive Mechanism to Repel Streptococcus oralis Biofilms.

To combat implant-associated infections, there is a need for novel materials which effectively inhibit bacterial biofilm formation. In the present study, the antiadhesive properties of titanium surface functionalization based on the "slippery liquid-infused porous surfaces" (SLIPS) principle were demonstrated and the underlying mechanism was analyzed. The immobilized liquid layer was stable over 13 days of continuous flow in an oral flow chamber system. With increasing flow rates, the surface exhibited a significant reduction in attached biofilm of both the oral initial colonizer  Streptococcus oralis and an oral multispecies biofilm composed of S. oralis, Actinomyces naeslundii, Veillonella dispar, and Porphyromonas gingivalis. Using single cell force spectroscopy, reduced S. oralis adhesion forces on the lubricant layer could be measured. Gene expression patterns in biofilms on SLIPS, on control surfaces, and expression patterns of planktonic cultures were also compared. For this purpose, the genome of S. oralis strain ATCC 9811 was sequenced using PacBio Sequel technology. Even though biofilm cells showed clear changes in gene expression compared to planktonic cells, no differences could be detected between bacteria on SLIPS and on control surfaces. Therefore, it can be concluded that the ability of liquid-infused titanium to repel S. oralis biofilms is mainly due to weakened bacterial adhesion to the underlying liquid interface.

Actinomyces naeslundii causing pulmonary endobronchial Actinomycosis - A case report.

Actinomyces naeslundii is a commensal flora of the oral cavity and is generally considered as an avirulent saprophytic bacterium in immunocompetent patients. It can become an opportunistic anaerobic pathogen in oral cavity in patients with poor oral hygiene or tooth extraction and can cause periodontal disease. Pulmonary Actinomycosis is a rare manifestation and may be suspected in middle-aged male patients with cough and hemoptysis showing radiological findings of a peripheral mass or chronic consolidation in whom repeated aerobic cultures have yielded negative results. Here, we report isolation of A. naeslundii from the bronchoalveolar lavage sample from an immunocompetent patient who presented with chronic nonresolving pneumonia of 6 months duration.

Actinomyces odontolyticus infection 3 months post-robotic-assisted laparoscopic prostatectomy.

Actinomyces odontolyticus infection is a rare bacterial infection with only 46 cases reported from its discovery in 1958. This case highlights an immunocompetent patient who presented with an infected lymphocele and bacteraemia following a robotic-assisted laparoscopic prostatectomy and extended pelvic lymph node dissection 3 months previously. He was treated for a fever of unclear origin initially using amoxicillin, gentamicin and metronidazole. Subsequently, he was found to have an infected lymphocele, which required surgical drainage. He was discharged 19 days after admission with three times daily oral amoxicillin which is to be continued for 6-12 months. This case highlights the need for effective communication between the laboratory and medical teams, and the importance of prompt source control.

Novel anti-biofouling light-curable fluoride varnish containing 2-methacryloyloxyethyl phosphorylcholine to prevent enamel demineralization.

We evaluated the efficacy of light-curable fluoride varnish (LCFV) that contains 2-methacryloyloxyethyl phosphorylcholine (MPC) in terms of anti-biofouling properties and prevention of tooth enamel demineralization. MPC was mixed with and incorporated into LCFV at 0 (control), 1.5, 3.0, 5.0, 10.0, 20.0, and 40.0 weight percentage (wt%). Addition of high wt% of MPC resulted in increased film thickness and decreased the degree of conversion, indicating loss of the advantageous properties of LCFV. Addition of 1.5, 3, or 5 wt% MPC significantly reduced the amount of bovine serum albumin adsorbed from a solution and proteins adsorbed from brain heart infusion medium compared to the control (P < 0.001). A similar pattern was observed for bacterial adhesion: significantly less Streptococcus mutans cells adhered on the surface of LCFV with 1.5, 3, or 5 wt% MPC (P < 0.001) than on the control, and similar results were obtained for Actinomyces naeslundii and Streptococcus sanguinis adherence to LCFV with 3 wt% MPC. Finally, bacterial adhesion, surface microhardness loss, and the depth of demineralization were substantially lower on bovine tooth enamel surface coated with LCFV containing 3 wt% of MPC than in the control treatment (0 wt% MPC). Therefore, this novel LCFV containing a low concentration of MPC (e.g., 3 wt%) would be effective in anti-biofouling while maintaining the important advantageous features of light-curable fluoride in preventing demineralization.

Lactobacillus plantarum Lipoteichoic Acid Inhibits Oral Multispecies Biofilm.

INTRODUCTION: Apical periodontitis is an inflammatory disease in the periradicular region of teeth that results from infection by multispecies bacterial biofilm residing in the root canal system. In this study, we investigated whether Lactobacillus plantarum lipoteichoic acid (Lp.LTA) could inhibit multispecies oral pathogenic bacterial biofilm formation. METHODS: Highly pure and structurally intact Lp.LTA was purified from L. plantarum. Actinomyces naeslundii, Lactobacillus salivarius, Streptococcus mutans, and Enterococcus faecalis were co-cultured to form oral multispecies biofilm in the presence or absence of Lp.LTA on culture plates or human dentin slices. Preformed biofilm was treated with or without Lp.LTA, followed by additional treatment with intracanal medicaments such as calcium hydroxide or chlorhexidine digluconate. Confocal microscopy and crystal violet assay were performed to determine biofilm formation. Biofilm on human dentin slices was visualized with a scanning electron microscope. RESULTS: Biofilm formation of multispecies bacteria on the culture dishes was dose-dependently reduced by Lp.LTA compared with the nontreatment control group. Lp.LTA also inhibited multispecies biofilm formation on the dentin slices in a dose-dependent manner. Interestingly, Lp.LTA was shown to reduce preformed multispecies biofilm compared with the nontreatment group. Moreover, Lp.LTA potentiated the effectiveness of the intracanal medicaments in the removal of preformed multispecies biofilm. CONCLUSIONS: These results suggest that Lp.LTA is a potential anti-biofilm agent for treatment or prevention of oral infectious disease, including apical periodontitis, which is mainly caused by multispecies bacterial biofilm.

Actinomicosis primaria intestinal. Informe de un caso en íleon y colon. Revisión de la literatura / Primary intestinal actinomycosis in ilium and colon. A case report and review of the literature

La actinomicosis es una enfermedad crónica, supurativa e inflamatoria granulomatosa causada por bacterias filamentosas grampositivas anaerobias del género Actinomyces, siendo más frecuente Actinomyces israelii. Caso clínico: hombre de 42 años de edad con dolor abdominal, pérdida de peso de 10kg y tumor en epigastrio adherido a planos profundos. La tomografía reveló dilatación de las asas intestinales; así como engrosamiento de las paredes de colon, por lo que se pensó en proceso linfoproliferativo. Se extirparon quirúrgicamente el tumor, fragmento íleon y colon; los cuales se encontraban adheridos por tejido fibroadiposo de la serosa. Microscópicamente se observó abundante infiltrado de leucocitos polimorfonucleares y gránulos de bacterias compatibles con Actinomyces spp

Actinomycosis is a chronic, suppurative, inflammatory granulomatous disease caused by gram positive anaerobic filamentous bacteria of the genus Actinomyces, most frequently Actinomyces israelii. We report a case of a 42-year-old male presenting with abdominal pain, a 10kg weight loss and a fixed mass in the epigastrium. Tomography revealed dilatation of the intestinal loops and thickening of the colon walls; the coexistence of these two findings suggested a lymphoproliferative process. The tumour, ileum fragment and colon were surgically removed; these were adherent to the serosal fibro-adipose tissue. Microscopically, abundant polymorphonuclear infiltrate and grains of bacteria compatible with Actinomyces spp.were seen

Actinomyces and Alimentary Tract Diseases: A Review of Its Biological Functions and Pathology.

Actinomyces are nonmotile, filamentous, Gram-positive bacteria that cause actinomycosis in immunodeficiency patients. Although the prognosis of actinomycosis is good, the diagnosis of actinomycosis is quite difficult. Recent studies on actinomycosis have shown that Actinomyces play an important role in various biological and clinical processes, such as the formation of dental plaque and the degradation of organics in the gastrointestinal tract. Here, the distribution of Actinomyces in the digestive tract, and different biological effects of actinomycosis, and its clinical association with inflammatory diseases are discussed. Furthermore, an overview of the most commonly used treatment methods and drugs used to treat Actinomyces infected alimentary canal diseases is presented.

Antibacterial Effect of Silver Diammine Fluoride on Cariogenic Organisms

AIM: To screen the possible antimicrobial activity of a range of clinically used, silver-based compounds on cariogenic organisms: silver diammine fluoride (SDF), silver fluoride, and silver nitrate. MATERIALS AND METHODS: Preliminary screening disk-diffusion susceptibility tests were conducted on Mueller-Hinton agar plates inoculated with Streptococcus mutans, Lactobacillus acidophilus, and Actinomyces naeslundii, organisms known to be cariogenic. In order to identify which component of the silver compounds was responsible for any antibacterial (AB) effect, and to provide controls, the following were also investigated at high and low concentrations: sodium fluoride, ammonium fluoride, ammonium chloride, sodium fluoride, sodium chloride, and sodium nitrate, as well as deionized water as control. A volume of 10 pL of a test solution was dispensed onto a paper disk resting on the inoculated agar surface, and the plate incubated anaerobically at 37°C for 48 hours. The zones of inhibition were then measured. RESULTS: Silver diammine fluoride, silver fluoride, silver nitrate, and ammonium fluoride had significant AB effect (p < 0.05) on all three test organisms, although ammonium fluoride had no effect at low concentration; the remaining other compounds had no effect. CONCLUSION: Silver ions appear to be the principal AB agent at both high and low concentration; fluoride ions only have an AB effect at high concentration, while ammonium, nitrate, chloride and sodium ions have none. The anticaries effect of topical silver solutions appears restricted to that of the silver ions. CLINICAL SIGNIFICANCE: Silver compounds, such as SDF, silver fluoride, and silver nitrate have AB effect against cariogenic organisms and these may have clinical impact in arresting or preventing dental decay. Sodium fluoride did not have AB effect under the conditions tested.

Sepsis neonatal secundaria a una corioamnionitis por Actinomyces neuii en una gestante de 25 semanas / Neonatal sepsis secondary to chorioamnionitis by Actinomyces neuii in a 25 weeks pregnant woman

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Actinomyces cavernous sinus infection: a case and systematic literature review.

A 63-year-old man presented with a 2-month history of progressive right-sided exophthalmos, painful ophthalmoplegia and fevers. As more features developed, he was diagnosed with giant cell arteritis, then Tolosa-Hunt syndrome, and transiently responded to corticosteroids. A bland cerebrospinal fluid and highly metabolically active brain (18F)-fluoro-D-glucose-positron emission tomography suggested lymphoma. Biopsy of the mass showed sulphur granules with Gram-positive filamentous bacteria with Actinomyces-like colonies. Actinomyces cavernous sinus infections are rare and indolent. They often mimic non-infective causes including other inflammatory and infiltrative conditions, vascular and neoplastic causes, particularly lymphoma. Clinicians should consider infective cavernous sinus syndromes in people with a fluctuating painful ophthalmoplegia that responds poorly to corticosteroids. The term Tolosa-Hunt syndrome is problematic and should be retired or used only with reservation.

Osteomielitis vertebral por Actinomyces: reporte de un caso / Vertebral osteomyelitis due to Actinomyces: a case report

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Case Report: Iatrogenic Infection from Traditional Treatment of Stingray Envenomation.

A 47-year-old man was stung on the left ankle by a stingray while on vacation on the Island of Bubaque, Guinea-Bissau. The affected limb was initially treated with an attempt to suck out the venom and application of chewed plant root. The following 3 days, local pain gradually diminished, but then high fever erupted together with generalized symptoms and intense pain from the ankle. After initiating antibiotic treatment, the patient was evacuated. Because of sustained symptoms and fever, the wound was surgically debrided, and culture revealed infection with oral flora bacteria. Attempts to suck out venom are not recommended.

Actinomicosis pulmonar en paciente con neumonía eosinófila crónica en tratamiento con omalizumab / Pulmonary Actinomycosis in a Patient with Chronic Eosinophilic Pneumonia treated with Omalizumab

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Pelvic actinomycosis and IUD.

OBJECTIVE: To summarize knowledge about the mana-gement in women with proven actinomyces in uterine cervix and inserted intrauterine device (IUD). DESIGN: An overall review. RESULTS: Actinomycosis is an uncommon but important subacute or chronic infection caused by anaerobic or microaerophilic bacteria, mainly within the Actinomyces genus. Actinomycosis can affect various organs and tissues in the human body, often manifesting draining sinuses, abscess formation and fibrosis. The pelvic form in women is the most common in the developed countries. Long-duration treatment with antibiotics can be completely effective even in cases of heavy disease. Although pelvic actinomycosis is predominantly associated with the longstanding use of intrauterine device, the risk of future symptomatic infection is extremly low even in women with a cervical Pap smear positive for actinomyces-like organisms (ALO). Therefore the identification of actinomycetes by cytology after cervical Pap smears is not diagnostic nor predictive of any disease because the actinomycetes normally reside in the female genital tract. In the absence of symptoms, patients with ALO on a Pap test do not need antimicrobial treatment or IUD removal. Nevertheless, women choosing an IUD for contraception should know that there is very low risk of developing the infection in later years after insertion. CONCLUSION: The sources of literature conclude that removal of the intrauterine device in a patients with a positive ALO in the uterine cervix is not necessary and antibiotics treatment is not required. However, IUD must be changed at least every five years in order to limit the risk of the development of pelvic actinomycosis.