Case Report: Acute large bowel obstruction with actinomycosis of the sigmoid colon mimicking neoplasm.

Introduction: Actinomycosis is an uncommon inflammatory bacterial disease caused by Actinomyces species, especially Actinomyces Israeli. Abdominopelvic forms are relatively rare and may involve the colon as a solid mass, mimicking a malignant tumor. Case presentation: A 68-year-old Tunisian man, with a history of diabetes, hypertension, penicillin allergy, and renal failure, presented to the emergency department with abdominal pain, vomiting, and bowel obstruction. CT scan showed an acute intestinal obstruction upstream with obstructive tissular mass at the sigmoid colon. Emergency surgery revealed a sigmoid mass and a pre-perforative cecum. Total colectomy was performed, with ileostomy and distal end closure. Histological examination confirmed Actinomyces infection. The patient was then placed on long-term doxycycline and Bactrim, with no recurrence over a 9-month follow-up period. Conclusion: Abdominal actinomycosis, though rare, presents diagnostic challenges. It can be mistaken for malignancy, leading to unnecessary surgery in non-complicated cases, since it is effectively treated by antibiotics. In complicated cases, a combined approach involving both surgery and antibiotic therapy is necessary until the infection is completely eradicated.

Understanding Actinomyces Odontolyticus: A Rare Culprit of Bacteremia.

Actinomyces species are gram-positive filamentous non-acid fast anaerobic to microaerophilic bacteria that belong to human oral, gastrointestinal, and urogenital tract flora. Cervicofacial, abdominopelvic, and pulmonary infections are the most common presentations. Hematogenous spread is extremely rare and has been associated with Actinomyces meyeri, Actinomyces israelii, and Actinomyces odontolyticus. It affects individuals with poor oral hygiene, heavy alcohol intake, immunosuppressed, and underlying pulmonary diseases typically between the second and sixth decades of life with the peak incidence being between the fourth and fifth decades. We present a case of A. odontolyticus bacteremia in a patient with uncontrolled diabetes mellitus and chronic sinusitis.

Actinomyces neuii Causing Right-Sided Infective Endocarditis: A Case-Based Literature Review.

Actinomyces neuii (also known as Winkia neuii nowadays), quite different from its genus,is a facultatively anaerobic organism that rarely causes human infections.Like the rest of its genus, it usually has a good prognosis. In this case report, we present an interesting case of a middle-aged female who presented to the emergency department (ED) with fever and dyspnea, eventually diagnosed with infective endocarditis (IE) caused by A. neuii. To the best of our knowledge, it is the first reported case of A. neuii causing right-sided infective endocarditis in a middle-aged female with no residual or prosthetic valvular disease.

Porphyromonas gingivalis LPS and Actinomyces naeslundii Conditioned Medium Enhance the Release of a Low Molecular Weight, Transcriptionally Active, Fragment of Glycogen Synthase-3 Kinase in IMR-32 Cell Line.

Background: Glycogen synthase-3 kinase (GSK3) is one of the major contributors of tau hyperphosphorylation linked to neurofibrillary tangles in Alzheimer's disease (AD). Objective: To determine a mechanism of GSK-3ß activation by two periodontal bacteria consistently confirmed in AD autopsied brains. Methods: Porphyromonas gingivalis FDC381 and Actinomyces naeslundii ATCC10301 conditioned media were collected. IMR-32 cells were challenged for 48 h with the conditioned media alongside P. gingivalis (ATCC33277) ultrapurified lipopolysaccharide (LPS) designated Pg.LPS under established cell culture conditions either alone or combined. Gene expression and protein analyses for GSK-3ß were carried out. Results: qPCR demonstrated that GSK-3ß gene was overexpressed in IMR-32 cells treated with Pg.LPS with a 2.09-fold change (p = 0.0005), while A. naeslundii treated cells demonstrated 1.41-fold change (p = 0.004). Western blotting of the cells challenged with Pg.LPS (p = 0.01) and A. naeslundii conditioned medium (p = 0.001) demonstrated the 37 kDa band for each treatment with variable intensity across the medium control. Immunohistochemistry with the GSK-3ß of the IMR-32 cells challenged with Pg.LPS and A. naeslundii alone demonstrated cytoplasmic and nuclear localization. Conclusions: Exposure to various bacterial factors upregulated the gene expression of GSK-3ß. Western blotting for GSK-3ß confirmed the presence of the cleaved fragment by Pg.LPS (37 kDa band p = 0.01) and A. naeslundii conditioned medium (37 kDa band p = 0.001). Immunostaining demonstrated both cytoplasmic and nuclear localization of GSK-3ß. Therefore, Pg.LPS and an unknown factor from the A. naeslundii conditioned medium mediated GSK-3ß activation via its transcriptionally active, cleaved, fragment. These virulence factors in the body appear to be detrimental to brain health.

Actinomyces funkei bacteraemia and infected pulmonary cavities in an intravenous drug user: a case report.

BACKGROUND: Actinomyces spp. are most commonly found in human commensal flora; however, they have also been shown to cause suppurative infections. We present a case of a rare Actinomyces funkei bacteraemia from an infected deep vein thrombosis in a patient who went on to develop pulmonary cavities secondary to septic emboli. Infected thrombi and septic emboli have been associated with other Actinomyces spp. in the literature, often posing a diagnostic challenge and, in some cases, causing drastic clinical deterioration in patients. The literature regarding Actinomyces funkei is scarce and to our knowledge there are no reports of a relationship between this Actinomyces subspecies and infected thrombi or septic emboli. CASE PRESENTATION: The patient was a 39-year-old known intravenous drug user who presented with a groin injecting site sinus and systemic symptoms. The bacteria was first observed by gram staining of a blood culture sample after 48 h of incubation and the species was identified using matrix-assisted laser desorption ionization time-of-flight (MALDI-TOF) as Actinomyces funkei. Sputum cytology/histology with cell block revealed a branching gram-positive species suspicious of slow growing bacteria or fungus. CT imaging of his lower limb and chest revealed an extensive DVT with inflammatory changes and pulmonary cavities respectively. The patient was treated with Ceftriaxone before being discharged with a 6-month course of Linezolid. He made a good recovery with reduction in size of the cavitating lung lesions on follow-up imaging. CONCLUSIONS: This case report presents a difficult-to-diagnose bacterial infection in an intravenous drug user, complicated by bacteraemia and secondary septic emboli. Relatively little is known about Actinomyces funkei, and therefore this report aims to increase clinician awareness of diagnosis, management, and complications.

Abdominal actinomycosis presented as acute abdomen with intra-abdominal multiple tumors: A case report.

INTRODUCTION AND IMPORTANCE: Actinomycosis, a rare infection caused by Actinomyces spp., typically presents as a chronic condition affecting various regions, particularly the cervicofacial, thoracic, and abdominal areas. Its diagnosis is often difficult due to symptom overlap with malignancies and other infections. This report details a case of abdominal actinomycosis mimicking multiple intra-abdominal tumors, complicating diagnosis and treatment. CASE PRESENTATION: A 67-year-old male with uncontrolled type 2 diabetes presented with generalized abdominal pain, nausea, vomiting, constipation, and significant weight loss. Physical examination revealed distention and severe abdominal tenderness. Laboratory tests showed leukocytosis and anemia. Diagnostic laparotomy revealed multiple intra-abdominal tumors. Histopathology confirmed actinomycosis without malignancy or tuberculosis. Intravenous amoxicillin was started; however, the patient discharged himself against medical advice after two days due to personal reasons unrelated to his treatment plan. He returned three months later with persistent abdominal pain and additional hepatic lesions. Extended antibiotic therapy for 12 months led to the resolution of symptoms during follow-up. CLINICAL DISCUSSION: Abdominal actinomycosis is rare and often associated with conditions like diabetes. This case underscores the infection's potential to mimic malignancy and highlights the need for considering actinomycosis in differential diagnoses of acute abdomen, especially in immunocompromised patients. The patient's uncontrolled diabetes likely contributed to the infection's development and spread. CONCLUSION: Abdominal actinomycosis can present acutely, mimicking neoplastic diseases with multiple intra-abdominal masses. Early recognition and prolonged antibiotic therapy are essential to prevent systemic spread, especially in immunocompromised individuals. Clinicians should consider actinomycosis in patients with poorly controlled diabetes and abdominal symptoms.

Prevalence of Helicobacter pylori in routine adult tonsillectomies.

Helicobacter pylori, a curved bacterial rod and causative agent of peptic ulcer and gastric adenocarcinoma, is found as an infectious agent in the stomach of over half of the global population. H. pylori has been identified in oral biofilms and its presence in adenotonsillar tissues has been suggested, with variations in testing methodology both proving and disproving its presence. The current study employed 119 formalin-fixed paraffin-embedded tonsillar tissues from an adult population (n=86) in a major metropolitan city with immunohistochemistry procedures using a monoclonal antibody to determine the incidence of H. pylori in the tonsils. H. pylori was identified in 72.1% of the patients and was associated with Actinomyces spp. in 92.0% of those cases. The high incidence of H. pylori in patients undergoing tonsillectomy suggests that H. pylori may be a contributing factor for tonsillitis and tonsillar hypertrophy. Furthermore, the reservoir for H. pylori in the tonsils may explain why some persons remain refractory to antibiotic treatment for gastric H. pylori.

Molecular basis for sortase-catalyzed pilus tip assembly.

During pilus assembly within the Gram-positive bacterial envelope, membrane-bound sortase enzymes sequentially crosslink specific pilus protein monomers through their cell wall sorting signals (CWSS), starting with a designated tip pilin, followed by the shaft made of another pilin, ultimately anchoring the fiber base pilin to the cell wall. To date, the molecular determinants that govern pilus tip assembly and the underlying mechanism remain unknown. Here, we addressed this in the model organism Actinomyces oris. This oral microbe assembles a pathogenically important pilus (known as type 2 fimbria) whose shafts, made of FimA pilins, display one of two alternate tip pilins-FimB or the coaggregation factor CafA-that share a markedly similar CWSS. We demonstrate that swapping the CWSS of CafA with that of FimB produces a functional hybrid, which localizes at the pilus tip and mediates polymicrobial coaggregation, whereas alanine-substitution of the conserved FLIAG motif within the CWSS hampers these processes. Remarkably, swapping the CWSS of the normal cell wall-anchored glycoprotein GspA with that of CafA promotes the assembly of hybrid GspA at the FimA pilus tip. Finally, exchanging the CWSS of the Corynebacterium diphtheriae shaft pilin SpaA with that of CafA leads to the FLIAG motif-dependent localization of the heterologous pilus protein SpaA at the FimA pilus tip in A. oris. Evidently, the CWSS and the FLIAG motif of CafA are both necessary and sufficient for its destination to the cognate pilus tip specifically assembled by a designated sortase in the organism. IMPORTANCE: Gram-positive pili, whose precursors harbor a cell wall sorting signal (CWSS) needed for sortase-mediated pilus assembly, typically comprise a pilus shaft and a tip adhesin. How a pilin becomes a pilus tip, nevertheless, remains undetermined. We demonstrate here in Actinomyces oris that the CWSS of the tip pilin CafA is necessary and sufficient to promote pilus tip assembly, and this functional assembly involves a conserved FLIAG motif within the CWSS. This is evidenced by the fact that an A. oris cell-wall anchored glycoprotein, GspA, or a heterologous shaft pilin from Corynebacterium diphtheriae, SpaA, engineered to have the CWSS of CafA in place of their CWSS, localizes at the pilus tip in a process that requires the FLIAG motif. Our findings provide the molecular basis for sortase-catalyzed pilus tip assembly that is very likely employed by other Gram-positive bacteria and potential bioengineering applications to display antigens at controlled surface distance.

Lactic Acid Bacteria in the Human Oral Cavity: Assessing Metabolic Functions Relevant to Oral Health and Disease.

Many perceive lactic acid bacteria as beneficial for health. They are recognized for preventing abnormal fermentation and spoilage of ingested foods by producing lactic acid, which aids in gut acidification. Moreover, lactic acid bacteria are extensively employed in food science. In contrast, lactic acid bacteria in the oral cavity are often perceived as pathogenic factors contributing to the development of dental caries. As a consequence, substantial research has been conducted in oral and dental sciences to explore lactic acid bacteria and the oral microbiome. This research primarily involves analyzing bacterial flora, investigating metabolic activities such as acid production, and investigating metabolic regulation within the oral environment. The oral cavity serves as the gateway to the digestive tract and respiratory system, characterized by a constantly fluctuating environment that significantly impacts the metabolic activity of lactic acid bacteria. Hence, when investigating oral lactic acid bacteria, it is crucial to adopt research plans and methodologies that account for these metabolic environment changes. In this section, we present some of the methods employed in our study.

Enhanced antimicrobial activity against oral bacteria Actinomyces viscous by cinnamaldehyde emulsion microencapsulated with cyclodextrin glycosyltransferase-catalyzed products.

Actinomyces viscous (A. viscous) is well documented as a major cariogenic bacterium in the oral cavity and needs to be inhibited and removed timely. Essential oils (EOs) are recognized as secure antibacterial agents for treating oral diseases, but their volatility and insolubility limit their application. In this study, cinnamaldehyde was screened as the optimum EO for inhibiting the A. viscous growth by a micro-agar dilution method and microencapsulated by cyclodextrin glycosyltransferase (CGTase)-catalyzed products. The antibacterial effects against A. viscous were investigated and compared with the free cinnamaldehyde. Antibacterial diameter, antibacterial efficiency and stability, and time-kill curve results revealed that the cinnamaldehyde emulsion had better antibacterial properties. 1 MIC of the cinnamaldehyde emulsion had an inhibitory zone of 9.92 nm, a 100 % inhibition rate when acting for 2 min or 5 min, and still maintained the same inhibitory effect for 2 years. The extracellular environment showed more pH decrease, conductivity increase, and protein leakage, suggesting damage to the cell membrane. Microstructure and flow cytometric analysis further revealed that the CGTase-catalyzed products induced more changes in the A. viscous membrane integrity. Based on the results, CGTase-catalyzed products can be used as a potential substance for encapsulating EOs for treating oral bacteria.

A case of Winkia neuii (Actinomyces neuii) vertebral osteomyelitis and review of the literature.

This case report presents an unusual occurrence of Winkia (Actinomyces) neuii vertebral osteomyelitis in a 55-year-old male patient with diabetes mellitus. W. neuii is a distinct species formerly placed within the Actinomyces genus, exhibiting unique morphological and clinical characteristics. Vertebral osteomyelitis caused by Actinomyces species is rare, with only one prior case reported in the literature. The patient was successfully managed with a combination of intravenous ceftriaxone during hospitalization and an oral antibiotic regimen for an extended period. This case report contributes to the limited body of knowledge surrounding W. neuii, as well as actinomycotic vertebral osteomyelitis.

Mimicry of Rhabdomyosarcoma by Tonsillar Actinomycosis: Case Report.

Actinomycosis is a rare infectious disease characterized by slowly progressive, chronic suppurative lesions, often mistaken for malignancies due to its ability to mimic them. It is caused by Actinomyces bacteria, which are part of the normal flora of the human oropharynx, gastrointestinal, and urogenital tracts. This case report describes a 51-year-old male with a history of mandibular rhabdomyosarcoma presenting with severe shoulder and hip pain, dysphagia, and headaches, initially suspected to be a cancer recurrence. However, after further investigation, including a PET-CT and tonsillectomy, the diagnosis of actinomycosis was confirmed through histopathological examination. The case highlights the diagnostic challenges of actinomycosis, especially in patients with complex clinical histories, emphasizing the importance of considering it as a differential diagnosis in similar presentations. The patient was treated with long-term antibiotic therapy, predominantly beta-lactams, demonstrating the necessity of a comprehensive diagnostic approach and the implications of a delayed diagnosis. This case underscores the critical need for high clinical suspicion and awareness among healthcare professionals regarding the potential for actinomycosis to mimic more common diseases, ensuring timely and accurate treatment.

Pulmonary Actinomycosis in a 65-Year-Old Female with Poor Oral Dentition.

Pulmonary actinomycosis is an uncommon clinical entity that can be challenging to diagnose due to its non-specific symptomatology. Misdiagnosis and delayed treatment may result in invasive procedures and extended antimicrobial treatment courses. We report a case involving a 65-year-old female with poor oral dentition admitted for acute respiratory failure subsequently found to have a left-sided pleural effusion and perihepatic abscess formation. Cytopathology examination and microbiology studies confirmed the diagnosis of pulmonary actinomycosis.

Actinomyces-infected bronchopulmonary sequestration: An uncommon pathogen in a rare anomaly.

Bronchopulmonary sequestration, a rare congenital anomaly, involves a nonfunctioning lung tissue mass supplied by anomalous vessels. It is rarely infected by Actinomyces, further complicating the clinical presentation, with limited reported cases. This case highlights the distinctive clinical aspects, diagnostic challenges, and successful management strategies of such a rare clinical entity.

Pulmonary mediastinal actinomycosis with "pound cake sign" on magnetic resonance imaging mimicking an infiltrative malignant tumor: A case report.

Actinomycosis is a rare chronic suppurative granulomatous disease. Surgical biopsy is often performed in patients with chest actinomycosis because malignancy is suspected in most cases. A 62-year-old man presented to our hospital with fever and exertional dyspnea that had persisted for several months. Contrast-enhanced computed tomography showed an irregularly shaped mass with contrast enhancement in the anterior mediastinum and consolidation in the left upper lung lobe contiguous with this mass, as well as multiple nodules in both lungs. The pulmonary artery trunk was stenotic and surrounded by the mass, and the right heart system was enlarged. Thoracoscopic biopsy was performed but failed to yield a diagnosis. Contrast-enhanced computed tomography after one month revealed an increased mass and worsening right heart strain. 18F-FDG (fluorodeoxyglucose) positron emission tomography/computed tomography and contrast-enhanced magnetic resonance imaging also suggested a malignant tumor, and an open chest biopsy was performed. No malignant cells were identified and actinomycetes were detected by histopathology and bacterial culture. The patient was treated with antibiotics, following which his contrast-enhanced computed tomography findings and general condition improved.

Development of selective isolation media for detecting the genera Actinomyces and Schaalia from oral specimens containing indigenous bacteria.

To isolate specific bacteria from samples constituting the microbiota, it is essential to employ selective media that suppress the growth of resident bacteria other than specific target bacteria. Selective media for clinically important Actinomyces (including Schaalia, which was previously taxonomically classified as part of the genus Actinomyces) have been limited because they have been designed for a limited range of species within the genus and require ingredients which are difficult to prepare and handle. This study aimed to develop a selective medium [referred to as Actinomyces and Schaalia Selective Medium (ASSM)] for the isolation of a broad range of Actinomyces and Schaalia species from samples mixed with resident bacteria. The composition of ASSM includes yeast extract, agar, brain heart infusion (BHI), levofloxacin (LVFX), fosfomycin (FOM), colistin (CL) and metronidazole (MNZ). Evaluation of the medium using 24 swab samples serially collected from the roots of the teeth of a healthy individual for whom metagenome sequencing data of a saliva sample are publicly available revealed that ASSM adjusted to concentrations of LVFX 0.5 mg l-1, FOM 5 mg l-1, CL 1 mg l-1 and MNZ 2 mg l-1 and cultured anaerobically at 35 °C for 7 days enabled the isolation of Actinomyces species from 37.5 % of the samples. The inclusion of CL and MNZ in ASSM can also be useful for samples harbouring other bacterial species. The selective isolation medium is expected to contribute to studies investigating the relationship between these bacteria and their pathogenesis or disease.

Coexisting Chronic Rhino-Cerebral Mucormycosis and Actinomyces Infection: A Case Report and Review of the Literature.

Fungal rhino-orbital-cerebral infections present significant treatment challenges, especially in immunocompromised individuals, such as those with diabetes. These infections seldom occur with bacterial co-infections, which complicate their management. This report presents the case of a 74-year-old diabetic male with a long-standing history of left malar pain who experienced rhinorrhea, nasal congestion, and confusion. Diagnostic imaging revealed angioinvasive fungal sinusitis, ultimately attributed to chronic mucormycosis (CM) with concurrent Actinomyces infection, a rarely reported occurrence. We employed a comprehensive treatment strategy, which resulted in a successful recovery after 24 days. Although CM is rare, accounting for approximately 5.6% of cases with mucormycosis, it requires thorough diagnostic evaluation and prolonged treatment. The rarity of co-infections like the one we describe underscores the need for an integrated management approach. Histopathological analysis serves as the gold standard for diagnosis, with treatment typically involving surgical and extensive antifungal interventions.

Polymicrobial infections with specific Actinomyces and related organisms, using the current taxonomy.

Actinomyces organisms reside on mucosal surfaces of the oropharynx and the genitourinary tract. Polymicrobial infections with Actinomyces organisms are increasingly being reported in the literature. Since these infections differ from classical actinomycosis, lacking of specific clinical and imaging findings, slow-growing Actinomyces organisms can be regarded as contaminants or insignificant findings. In addition, only limited knowledge is available about novel Actinomyces species and their clinical relevance. The recent reclassifications have resulted in the transfer of several Actinomyces species to novel genera Bowdeniella, Gleimia, Pauljensenia, Schaalia, or Winkia. The spectrum of diseases associated with specific members of Actinomyces and these related genera varies. In human infections, the most common species are Actinomyces israelii, Schaalia meyeri, and Schaalia odontolytica, which are typical inhabitants of the mouth, and Gleimia europaea, Schaalia turicensis, and Winkia neuii. In this narrative review, the purpose was to gather information on the emerging role of specific organisms within the Actinomyces and related genera in polymicrobial infections. These include Actinomyces graevenitzii in pulmonary infections, S. meyeri in brain abscesses and infections in the lower respiratory tract, S. turicensis in skin-related infections, G. europaea in necrotizing fasciitis and skin abscesses, and W. neuii in infected tissues around prostheses and devices. Increased understanding of the role of Actinomyces and related species in polymicrobial infections could provide improved outcomes for patient care. Key messages Due to the reclassification of the genus, many former Actinomyces species belong to novel genera Bowdeniella, Gleimia, Pauljensenia, Schaalia, or Winkia.Some of the species play emerging roles in specific infection types in humans.Increasing awareness of their clinical relevance as an established or a putative pathogen in polymicrobial infections brings about improved outcomes for patient care.

Antibacterial Effect of Ozone on Cariogenic Bacteria and Its Potential Prejudicial Effect on Dentin Bond Strength-An In Vitro Study.

Ozone is increasingly utilized in dental caries treatment due to its antibacterial properties. In a context of limited studies and no consensus on protocols, this research aims to assess ozone's antibacterial efficacy on cariogenic bacteria and its potential adverse impact on dentin bond strength. Streptococcus mutans, Streptococcus sobrinus, Lactobacillus casei, and Actinomyces naeslundii suspensions were exposed to 40 µg/mL of ozone gas and 60 µg/mL of ozonated water (80 s) via a medical ozone generator. Negative and positive control groups (chlorhexidine 2%) were included, and UFC/mL counts were recorded. To examine microtensile bond strength (µTBS), 20 human molars were divided into four groups, and class I cavities were created. After ozone application, samples were restored using an etch-and-rinse and resin composite, then sectioned for testing. The SPSS v. 28 program was used with a significance level of 5%. The µTBS results were evaluated using one-way ANOVA, Tukey HSD, and Games-Howell. Bacterial counts reduced from 106 to 101, but dentin µTBS was significantly impacted by ozone (ANOVA, p < 0.001). Despite ozone's attractive antibacterial activity, this study emphasizes its detrimental effect on dentin adhesion, cautioning against its use before restorative treatments.

Lacrimal Canaliculitis: A Major Review.

Lacrimal canaliculitis is an inflammation of the proximal lacrimal drainage system. It classically presents with symptoms of redness, mucopurulent discharge, medial canthal swelling, epiphora, and pouting punctum. Despite having classical clinical characteristics it is frequently misdiagnosed. The cause can be primarily due to various infectious agents or secondary mostly due to the use of punctal plugs. There are no universally accepted guidelines for the management of canaliculitis but different medical and surgical options have been employed with varying success rates and it is notorious for recurrences and failure to therapy. The present review summarizes the existing literature on lacrimal canaliculitis published over the past 15 years to provide an overview of this uncommon condition. A total of 100 articles published in the literature were anlaysed during this period. The mean age at diagnosis was 57.09 ± 16.91 years with a female preponderance. Misdiagnosis was common with many patients misdiagnosed as conjunctivitis and dacryocystitis. Primary canaliculitis was found to be more frequent than secondary with inferior canaliculus involved more commonly than the superior. Staphylococcus, Streptococcus, and Actinomyces were the most common microbes isolated. Surgical management was employed in 74.25% of cases while medical management was done in 20.82% of cases. The review presents an insight into the complexities of canaliculitis, its diagnosis, and management which will further help to improve the understanding of this uncommon infection of the lacrimal system.