Skin and Soft Tissue Actinomycosis in Children and Adolescents.

BACKGROUND: Pediatric actinomycosis studies are limited to case reports or small case series. In this retrospective cohort study, we aimed to describe characteristics of skin and soft tissue actinomycosis in adolescents and children. METHODS: We conducted the study from January 2019 to December 2022, including patients ≤21 years of age with at least 1-year follow-up data. All clinical cultures obtained under sterile conditions with Actinomyces growth were included. RESULTS: One hundred four patients met inclusion criteria; median age 19 (interquartile range: 17-20) years, 68.3% female, 46.2% Black and 47.1% Hispanic. The median antibiotic treatment duration was 10 (7-10) days, and majority of patients received treatment with non-first-line Actinomyces antibiotics. Infectious disease consultation was requested for only 7 patients during their initial skin and soft tissue actinomycosis treatment. One-third of the patients with skin and soft tissue actinomycosis had documented recurrence within a median of 10 (interquartile range: 6-16) months of the initial episode. Monobacterial culture growth (85.7% vs. 63.8%, P = 0.02), patients with body mass index >25 (75% vs. 52.6%, P = 0.04) and patients with prior abscess in the same area (18.8% vs. 51.4%, P = 0.001) were significantly higher in patients with recurrent actinomycosis compared to the nonrecurrent group. In a univariate logistic regression model, they were found to be significantly associated with recurrence; monobacterial growth [odds ratio (OR): 3.4; 95% confidence interval (CI): 1.2-9.9], body mass index >25 (OR: 2.7; 95% CI, 1.1-7.0) and prior abscess (OR: 4.6; 95% CI: 1.9-11.2). CONCLUSIONS: Our study results highlight the importance of considering Actinomyces species in skin and soft tissue infections, especially in recurrent ones, and risk factors for recurrence. Suboptimal antibiotic utilization, very low numbers of consultations with infectious diseases and high recurrence rate suggest that providers should be informed and updated regarding this rare but hard-to-treat infection.

Appendecular actinomycosis: A case series of 14 patients.

OBJECTIVE: This study aims to assess the clinical, radiological, and histological characteristics of Actinomyces infection identified in appendectomy specimens. MATERIAL AND METHODS: Between January 2013 and November 2023, 5834 patients underwent appendectomy in our clinic, and their pathology reports were retrospectively reviewed. RESULTS: Actinomyces appendicites were reported in 14 specimens (0.23%). It was determined that appendectomy was performed in only 10 patients (71.4%), ileocecal resection was performed in two patients (14.2%) and right hemicolectomy in two patients (14.2%). The operations on five patients were performed by laparoscopy, and the operations on the other nine patients were performed by open surgery. Laparoscopy was started in three patients and converted to open surgery due to suspicion of an ileocecal mass and cecal perforation. It was found that the white blood cell count of three patients was within the normal range of reference (8-9.77mg/dL); leukocytosis was detected in other patients (10.2-18.7mg/dL). C-reactive protein was normal in one patient and high in the rest of the patients. While the first-hour erythrocyte sedimentation rate was normal in five patients, it was found to be high in the other patients. Findings on radiological imaging were reported as acute appendicitis, appendicular plastron, and ileocecal mass. As a result of the pathology findings, the patients were given oral penicillin or semi-synthetic penicillin derivatives during one month. CONCLUSION: Ileocecal and appendecular actinomycosis are rare, and preoperative diagnosis is difficult. A definitive diagnosis is usually made after a histopathological examination. After surgery, long-term antimicrobial treatment of the patient is possible with penicillin.

Intestinal Bacteria Fluctuating in Early-Stage Colorectal Cancer Carcinogenesis are Associated with Diet in Healthy Adults.

This hospital-based, cross-sectional study aimed to explore the association between diet and fluctuating intestinal bacteria in early-stage colorectal cancer (CRC) (Atopobium parvulum, Actinomyces odontolyticus, Solobacterium moorei, and Bifidobacterium longum). Healthy participants (n = 212) who underwent total colonoscopy at National Cancer Center Hospital (Tokyo, Japan) were divided into two groups according to the relative abundance of bacteria in their feces: those in the top 25% of relative bacterial abundance as cases and the bottom 25% as controls. The participants were divided into three groups (low, medium, and high) according to their intake of food groups associated with CRC. Multivariable logistic regression analysis was conducted to estimate the association between dietary intake and higher relative abundance of bacteria. Dairy products were inversely associated with a higher relative abundance of A. parvulum, A. odontolyticus, and S. moorei, with odds ratios (high vs. low) and 95% confidence interval as follows: 0.16 (0.06-0.44), 0.25 (0.08-0.82), and 0.29 (0.11-0.78), respectively. Additionally, dietary fiber was inversely associated with a higher relative abundance of S.moorei (0.29 [0.11-0.78]). No association was observed between diet and B.longum. In conclusion, healthy adults with a higher intake of dairy products and fiber had lower odds of having a higher relative abundance of CRC-associated microbiota.

A rare case report of liver masses caused by Actinomyces species.

Actinomycosis is a rare infection caused by Actinomyces spp. Of all actinomycosis infections, only 5% of Hepatic Actinomycosis (HA) infection has been reported. This disease is often misdiagnosed as a malignancy. This case report presents a 45-year-old woman with diabetes, initially suspected of intrahepatic cholangiocarcinoma, but after careful tissue staining, we found the results supported HA infection.

[Skin abscess caused by Actinomyces radingae]. / Hautabszess verursacht durch Actinomyces radingae.

We report a 77-year-old man with a skin abscess caused by Actinomyces radingae. Targeted antibiotic therapy with amoxicillin/clavulanic acid for 6 weeks resulted in clearing of the infection. A. radingae is a rare pathogenic agent of skin and soft tissue infections. As with other Actinomyces infections, the early identification of the pathogen and specific antibiotic therapy is crucial for successful resolution of the infection because of the chronic course and the long treatment time needed. Usually, A. radingae is sensitive to ß­lactam antibiotics.

Actinomyces-induced Osteomyelitis of the Mandible - A Rare Disease?

BACKGROUND: Actinomyces species are commensal oral cavity flora that can cause jaw osteomyelitis. Osteomyelitis of the jaw by Actinomyces is rare, and its presentation can be confused with many different pathologies. CASE PRESENTATION: This is the case of a 61-year-old female with breast cancer and on chemotherapy as well as non-invasive carcinoma of the tongue who initially presented to the dentist with white spots in the right mandible near the incisors associated with right mandible pain and swelling. Actinomyces-induced osteomyelitis of the mandible was diagnosed. The patient was treated with penicillin V for 6 weeks along with a course of hyperbaric oxygen therapy, which resulted in the complete resolution of the infection. CONCLUSION: In summary, jaw osteomyelitis caused by Actinomyces should always be part of the differential diagnosis; as these organisms are commensal flora. The symptoms manifested are non-specific, and such a diagnosis could be easily missed, resulting in delay of care and disease progression.

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.

Characterization of isolates of members of the genus Actinomyces from Marmota himalayana: description of Actinomyces faecalis sp. nov., Actinomyces respiraculi sp. nov., and Actinomyces trachealis sp. nov.

Six novel strains (ZJ34T, ZJ561, ZJ750T, ZJ1629, zg-993T and zg-987) isolated from faeces and respiratory tracts of Marmota himalayana from the Qinghai-Tibet Plateau of PR China were characterized comprehensively. The results of analyses of the 16S rRNA gene and genome sequences indicated that the six strains represent three novel species of the genus Actinomyces, and are closely related to Actinomyces urogenitalis DSM 15434T (16S rRNA gene sequences similarities, 94.9-98.7 %), Actinomyces weissii CCUG 61299T (95.6-96.6 %), Actinomyces bovis CCTCC AB2010168T (95.7 %) and Actinomyces bowdenii DSM 15435T (95.2-96.4 %), with values of digital DNA-DNA hybridization less than 30.1 % when compared with their closest relatives but higher than 70 % within each pair of novel strains (ZJ34T/ZJ561, ZJ750T/ZJ1629 and zg-993T/zg-987). All the novel strains had C18 : 1 ω9c and C16 : 0 as the two most abundant major fatty acids. MK-9(H4) or MK-8(H4) was the sole or predominant respiratory quinone of strains ZJ34T, ZJ750T and zg-993T and their polar lipid profiles differed, but all had diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, and phosphatidyl inositol mannoside as major components. ZJ750T shared identical peptidoglycan amino acid profile with ZJ34T (alanine, glutamic acid, lysine and ornithine) and the same whole-cell sugar composition with zg-993T (glucose, rhamnose and ribose). Strain zg-993T contained alanine, aspartic acid, glutamic acid, glycine and lysine in the peptidoglycan, and the only sugar in ZJ34T was ribose. The DNA G+C contents of the novel strains were within the range of 65.8-70.1 mol%. On the basis of the results from the aforementioned analyses, the six novel strains were classified as representing three novel species of genus Actinomyces, for which the names Actinomyces faecalis sp. nov. [type strain ZJ34T (=GDMCC 1.1952T=JCM 34355T)], Actinomyces respiraculi sp. nov. [type strain ZJ750T (=GDMCC 1.1950T=JCM 34356T)] and Actinomyces trachealis sp. nov. [type strain zg-993T (=GDMCC 1.1956T=JCM 34357T)] were proposed, respectively.

Molecular identification and antibiotic resistance pattern of actinomycetes isolates among immunocompromised patients in Iran, emerging of new infections.

Recent advancements in DNA-based approaches have led to the identification of uncommon and rare bacterial pathogens. In this study, by utilizing a DNA-based approach, a total of 1043 clinical specimens were processed for the identification of actinobacteria targeting the 16S rRNA and gyrB genes. Drug susceptibility testing was also conducted using micro-broth dilution and PCR. Two isolates of Nocardia flavorosea and Rhodococcus erythropolis were reported for the first time in Iran. Also, Nocardiopsis dassonvillei, Streptomyces olivaceus, and Streptomyces griseus were reported for the first time in Asia. Infections caused by Nocardia caishijiensis and Prauserella muralis have also been reported in this study. The first Asian case of pulmonary infection caused by Nocardia ignorata and the first global case of brain abscess caused by Nocardia ninae and Nocardia neocaledoniensis have been reported in this study. Overall 30 isolates belonging to 6 genera (Nocardia, Streptomyces, Rodoccoccus, Nocardiopsis, Rothia, and Prauserella) were detected in 30 patients. All 30 isolates were susceptible to amikacin and linezolid. Three isolates including Nocardia otitidiscaviarum (n = 2) and Nocardia flavorosea (n = 1) were resistant to trimethoprim-sulfamethoxazole which were the first trimethoprim-sulfamethoxazole resistant clinical actinomycetes in Iran. Isolation of rare species of actinomycetes particularly Nocardia spp. requires urgent action before they spread clinically particularly among immunocompromised patients.

[The role of piezosurgery in the treatment of a rare case of superinfected cemento-osseous dysplasia caused by actinomyces: a case report]. / L´intérêt de la piézochirurgie dans le traitement d'une dysplasie cémento-osseuse surinfectée par actinomycose: à propos d'un cas.

Cemento-osseous dysplasia is a benign fibro-osseous lesion affecting the alveolar bone. It is classified into three forms: periapical, focal or florid dysplasia. It is often asymptomatic and fortuitously discovered during a routine radiological examination. However, it may become symptomatic after superinfection, after patient's exposure to oral bacterial flora. We here report a case of florid cemento-osseous dysplasia associated with actinomycosis of bone in a 53-year-old Tunisian woman. This superinfection has been rarely reported in the literature; Boolean Searching on PubMed for the keywords "cemento-osseous dysplasia AND actinomyces" displays a single article (Smith et al. 2011). The treatment of actinomycosis infection often requires long-term antibiotic therapy, sometimes associated with surgical debridement, as in the case of this patient who underwent piezosurgery to treat dysplasia and necrotic bone.

Lung adenocarcinoma and pulmonary actinomycosis: a cautionary tale.

BACKGROUND: Pulmonary actinomycosis is a rare and slowly progressive bacterial infection that is often mistaken for lung cancer. Multiple case reports caution against premature diagnosis of malignancy without proper consideration of potential Actinomyces infection. However, no cases in the English literature have been reported that demonstrate the possible coexistence of Actinomyces and lung cancer. CASE DESCRIPTION: We present two cases of patients with culture-positive Actinomyces who were later found to have concomitant biopsy-proven lung adenocarcinoma. CONCLUSIONS: In the workup of a newly identified lung mass, positive culture for Actinomyces does not rule out an underlying malignancy.

No man's land: Species-specific formation of exclusion zones bordering Actinomyces graevenitzii microcolonies in nanoliter cultures.

To survive within complex environmental niches, including the human host, bacteria have evolved intricate interspecies communities driven by competition for limited nutrients, cooperation via complementary metabolic proficiencies, and establishment of homeostatic relationships with the host immune system. The study of such complex, interdependent relationships is often hampered by the challenges of culturing many bacterial strains in research settings and the limited set of tools available for studying the dynamic behavior of multiple bacterial species at the microscale. Here, we utilize a microfluidic-based co-culture system and time-lapse imaging to characterize dynamic interactions between Streptococcus species, Staphylococcus aureus, and Actinomyces species. Co-culture of Streptococcus cristatus or S. salivarius in nanoliter compartments with Actinomyces graevenitzii revealed localized exclusion of Streptococcus and Staphylococcus from media immediately surrounding A. graevenitzii microcolonies. This community structure did not occur with S. mitis or S. oralis strains or in co-cultures containing other Actinomycetaceae species such as S. odontolyticus or A. naeslundii. Moreover, fewer neutrophils were attracted to compartments containing both A. graevenitzii and Staphylococcus aureus than to an equal number of either species alone, suggesting a possible survival benefit together during immune responses.

Kibdelosporangium persicum sp. nov., a new member of the Actinomycetes from a hot desert in Iran.

Isolate 4NS15T was isolated from a neglected arid habitat in Kerman, Iran. The strain showed 16S rRNA gene sequence similarity values of 98.9 % to the type strains of Kibdelosporangium aridum subsp. aridum, Kibdelosporangium phytohabitans and Kibdelosporangium philippinense and 98.6 % to the type strain K. aridum subsp. largum, respectively. Genome-based phylogenetic analysis revealed that isolate 4NS15T is closely related to Kibdelosporangium aridum subsp. aridum DSM 43828T. The digital DNA-DNA hybridization value between the genome sequences of 4NS15T and strain DSM 43828T is 29.8 %. Strain 4NS15T produces long chains of spores without a sporangium-like structure which can be distinguished from other Kibdelosporangium species. Isolate 4NS15T has a genome size of 10.35 Mbp with a G+C content of 68.1 mol%. Whole-cell hydrolysates of isolate 4NS15T are rich in meso-diaminopimelic acid and cell-wall sugars such as arabinose, galactose, glucose and ribose. Major fatty acids (>10 %) are C16 : 0, iso-C16 : 0 and iso-C15 : 0. The phospholipid profile contains diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylhydroxyethanolamine, aminolipid and glycoaminolipid. The predominant menaquinone is MK-9(H4). Based on its phenotypic and genotypic characteristics, isolate 4NS15T (NCCB 100701=CIP 111705=DSM 110728) merits recognition as representing a novel species of the genus Kibdelosporangium, for which the name Kibdelosporangium persicum sp. nov. is proposed.

Actinomyces in Forensic Practice.

ABSTRACT: A 19-year-old woman in septic shock with recent computed tomography findings of a loculated hepatic abscess was transferred to an intensive care unit where she went into asystolic cardiac arrest. After resuscitation, surgical exploration revealed a purulent pericardial effusion with tamponade and a liver abscess. Microbiological analyses from both sites were negative. Shortly after surgical exploration, she developed multiorgan failure and died. At autopsy, pus was observed both within the pericardial cavity and around the left lobe of the liver. Green "sulfur granules" suggestive of infection with Actinomyces spp. were able to be extruded from the liver during the postmortem examination and cultures returned positive for Actinomyces israelii. This case is a rare example of primary hepatic actinomycosis infection that resulted in the death of a young woman. Nonspecific clinical manifestations may delay diagnosis; however, the finding of "sulfur granules" in areas of abscess formation at autopsy should be taken as an indication of possible underlying Actinomyces infection.

Evaluation of Ultrasound Biomicroscopy Combined with Color Doppler Flow Imaging in the Diagnosis of Primary Lacrimal Canaliculitis.

Purpose: To explore the performance of ultrasound biomicroscopy (UBM) and color Doppler flow imaging (CDFI) in the diagnosis of primary lacrimal canaliculitis.Methods: Subjects with relevant symptoms of canaliculitis were prospectively recruited. UBM and CDFI were performed for presumptive diagnosis. Microbiology and histopathology were performed for definitive diagnosis.Results: A total of 37 cases were recruited, including 25 cases of canaliculitis and 12 cases of non-canaliculitis. Pathogens were isolated in 13 canaliculitis cases, and the leading pathogens were Actinomyces (4 cases) and Streptococcus (4 cases). UBM and CDFI identified 24 canaliculitis cases (sensitivity = 96%) and 11 non-canaliculitis cases (specificity = 92%). The predictive factors for canaliculitis were lumen wall thickness >0.25 mm (P = .019) and intracanalicular concretions (P = .010). Other typical features were enlarged lumen (2.16 ± 0.25 mm) and hot-wheel sign-on CDFI (84%). These image findings were congruent with histopathologic changes.Conclusion: Ultrasonography is a valuable tool to assist the diagnosis of canaliculitis.(Clinical trial registration number: ChiCTR1900025411).

[Our experiences with Actinomyces urogenitalis in human clinical samples].

Actinomyces urogenitalis is most commonly associated with the human genitourinary system, often only as the resident flora. Outside the genitourinary tract, A. urogenitalis is isolated rather sporadically. Presented are two brief case reports of human infections outside the genitourinary tract as well as experiences with microbiological identification of this actinomycete. Antibiotic susceptibility testing of actinomycetes is focused especially on their resistance to lincosamides and fluoroquinolones. The etiological relationship with the patients' clinical problems was not investigated. Previously reported cases of infections outside the genitourinary tract are also mentioned in the article. The article may aid in expanding the knowledge of the occurrence, diagnosis and susceptibility of A. urogenitalis to antibiotics, particularly in rarely reported extra-genitourinary infections caused by this species. Accurate species identification in routine laboratory practice is important both for determination of the etiological role of the microorganism and for more precise selection of empirical antibiotic therapy.