Osteomyelitis of a long bone due to Fusobacterium nucleatum and Actinomyces meyeri in an immunocompetent adult: a case report and literature review

A Strange Case of Traumatic Pleural Effusion: Pleural Empyema Due to Actinomyces meyeri, a Case Report

BACKGROUND

Actinomycosis by Actinomyces meyeri is rare and scarcely reported in the literature. The lung is the main organ involved. Penicillin and amoxicillin are the first-choice treatments. Surgery is indicated when empyema and abscesses are resistant to medical treatment.

CASE PRESENTATION

We report an underdiagnosed case of pleural empyema due to A. meyeri in a patient with closed chest trauma. The patient, a male, 47 years old, presented with a dry cough, thoracic pain, and dyspnea a month after the trauma. A chest X-ray showed a left lower lobe pleural effusion, so he was subjected to a thoracentesis, leading to a partial re-expansion of the left lung. The patient also complained about gum discomfort; thus, a dental x-ray scan was taken, which showed the presence of vertical bone resorption in a periodontal pocket. The patient was treated with levofloxacin 500 mg orally once a day, which was continued for 15 days after discharge. Two months after the accident, he presented again with intermittent fever, a worsening cough, and dyspnea. A CT scan showed thickening of the left pleura and a loculated pleural effusion with partial collapse of the left lower lobe. A decision was made to refer the patient to the Thoracic Unit to undergo surgery via a left thoracoscopic uniportal approach. The lung was thoroughly decorticated, and the purulent fluid was aspirated. The postoperative course was uneventful. Cultures showed the growth of Actinomyces meyeri, which is sensitive to imipenem and amoxicillin. The patient started a proper antibiotic regimen and, whenever possible, was discharged. At 12 months follow-up, a chest X-ray showed a complete resolution of the left pleural effusion with complete re-expansion of the left lung.

CONCLUSIONS

Although rare, Actinomycetes infections must be considered especially in front of non-solving empyema or severe pneumonia of unknown cause because in the majority of cases, with the proper treatment, the restitutio ad integrum is possible.

A first case of prosthetic joint infection with Actinomyces radingae

Prosthetic joint infection is a common clinical orthopedic problem but infections caused by Actinomyces species have been rarely reported. An increasing number of reports identifying Actinomyces in cases of prosthetic joint infection suggest it may be an emerging pathogen. We describe here the first known case of a prosthetic joint infection caused by Actinomyces radingae.

Progressive Ankle Subluxation Following Panfibular Osteomyelitis Requiring Fibular Resection

A 10-month-old boy presented with fever, a swollen left leg, and septicemic shock. He was diagnosed with panfibular osteomyelitis. Failure of combined medical and surgical treatment to achieve source control necessitated fibular resection. He subsequently developed a progressive superolateral subluxation of his left ankle, valgus deformity, and brace intolerance. Tibiotalar arthrodesis resulted in a stable plantigrade ankle, excellent weight-bearing ability, and a minor leg-length discrepancy at the 14-month postoperative follow-up.

More Than Just a Periodontal Pathogen –the Research Progress on Fusobacterium nucleatum

Fusobacterium nucleatum is a common oral opportunistic bacterium that can cause different infections. In recent years, studies have shown that F. nucleatum is enriched in lesions in periodontal diseases, halitosis, dental pulp infection, oral cancer, and systemic diseases. Hence, it can promote the development and/or progression of these conditions. The current study aimed to assess research progress in the epidemiological evidence, possible pathogenic mechanisms, and treatment methods of F. nucleatum in oral and systemic diseases. Novel viewpoints obtained in recent studies can provide knowledge about the role of F. nucleatum in hosts and a basis for identifying new methods for the diagnosis and treatment of F. nucleatum-related diseases.

Septic hip abscess due to Fusobacterium nucleatum and Actinomyces turicensis in an immunocompetent SARS-CoV-2 positive patient

A 42-year-old man was referred to the Department of Orthopedic Surgery with pain over his right greater trochanter and signs of systemic infection. CT showed an enhanced mass in his gluteus maximus as well as gas in the biceps femoris over the underlying hip joint. Tissue biopsy yielded Fusobacterium nucleatum and Actinomyces turicensis. The patient was successfully treated for 6 weeks with amoxicillin/clavulanic acid 875mg/125mg and metronidazole 500mg.

Clinical features of actinomycosis: A 20-year experience of a single institute in Southern China

BACKGROUND

Actinomycosis is a rare indolent infectious disease with nonspecific clinical presentations that delay diagnosis. Although actinomycosis is thought to be more prevalent in developing countries, data from developing countries are scarce. This study aimed to profile actinomycosis in developing countries and identify how it differed from profiles of developed countries.

METHODS

Patients fulfilling the inclusion criteria for actinomycosis from Nanfang Hospital in southern China between January 1999 and December 2018 were retrospectively analyzed. We described clinical characteristics, diagnostic procedures, differential diagnosis, and management of actinomycosis of clinical significance.

RESULTS

Thirty‑one patients were included in this study. The disease was diagnosed predominately in the orocervicofacial (n = 14), cardiothoracic (n = 11), abdominopelvic (n = 5), and soft tissue (n = 1) regions. Diagnosis was obtained by either histopathology (n = 29, 94%) or microbiology (n = 2, 6%). Only one-third of patients presented with general symptoms, such as fever and weight loss. Ten were lost during follow-up, and the median duration of antibiotic use was 93.5 days (interquartile range 28-300), whereas the median follow-up time was 34 months (interquartile range 9-132). Ten patients receiving complete resection of the lesion were cured without postoperative use of antibiotics. Only one patient relapsed during the follow-up period.

CONCLUSIONS

Actinomycosis is a rare disease even in developing countries, and both misdiagnosis and missed diagnosis are common. Diagnosis was often delayed and was obtained postoperatively from histopathology in developing countries. Hence, clinicians should be aware of this disease in patients with high risk factors. In the future, specific molecular methods may help to improve early diagnosis and treatment.

Lemierre's syndrome with muscle necrosis and chronic osteomyelitis

Lemierre's syndrome is a rare disorder characterized by thrombophlebitis of the internal jugular vein and is caused by gram-negative anaerobes, primarily Fusobacterium necrophorum. We report a case of a 20-year-old man who developed chronic osteomyelitis of the femur and myonecrosis of thigh muscles secondary to this syndrome. The diagnosis was made based on clinical presentation and evidence of thrombosis in the internal jugular vein on ultrasound. The patient was initially treated with antibiotics, and anticoagulants were added later due to deep vein thrombosis in the lower limb.

Full Femoral Osteomyelitis Caused by Fusobacterium nucleatum in an Immunocompetent Adult: A Case Report

CASE

We present a 46-year-old man who developed a full femoral osteomyelitis caused by Fusobacterium nucleatum. The subtle presentation of the infection and the late onset of appropriate antibiotic treatment caused a devastating bone quality of the full femur.

CONCLUSIONS

A successful outcome was obtained with surgical debridement, antibiotics, and return to weight bearing guided by a laboratory and radiographic scale specially designed to avoid pathologic fractures toward his full functional recovery.

Mycobacterial and Plasmodium ovale-associated destruction of the jaw bones

OBJECTIVES

The project aims were to identify infectious mechanisms responsible for an extreme form of mandibular osteonecrosis and osteomyelitis in West African populations and test the hypothesis that Mycobacterium tuberculosis plays a pivotal role.

MATERIALS AND METHODS

DNA was extracted from mandibular fragments of 9 of 19 patients previously included in a prospective study leading to the mycobacterial hypothesis. Amplified DNAs were used for preparing libraries suitable for next-generation sequencing. For comparison of the whole-genome sequencing data of the 9 patients with DNAs of both microbiota and human tissues, DIAMOND v0.9.26 was used to align sequencing reads to NCBI-nr database and MEGAN 6 for taxonomy binning and identification of Mycobacterium tuberculosis strains.

RESULTS

The data show that mandibular bone fragments of all 9 patients not only contain Homo sapiens and Mycobacterium tuberculosis DNAs; they also contain DNAs of Plasmodium ovale wallikeri, Staphylococcus aureus, Staphylococcus hominis, and Prevotella P3-120/intermedia; as well as large numbers of DNAs from other infectious components.

CONCLUSIONS

The data obtained provide direct evidence to support the conclusion that combinations of Mycobacterium tuberculosis, Plasmodium ovale wallikeri, and other oral bacteria are involved in this particular type of mandibular destruction in West African individuals of many ages.

Actinomycotic osteomyelitis of a long bone in an immunocompetent adult: a case report and literature review

BACKGROUND

Actinomycosis is a rare, chronic granulomatous disease caused by Gram-positive anaerobic bacteria that colonize the oral cavity. Cervicofacial actinomycosis is the most frequent clinical presentation of actinomycosis, but hematogenous osteomyelitis at distant sites can occur in rare instance in immunocompromised or pediatric patients, only a few cases have been reported in healthy patients. Here we described a new case of distal femur osteomyelitis caused by Actinomyces in an adult patient who was immunocompetent and had no predisposing factors.

CASE PRESENTATION

A woman aged 52 years with no history of trauma presented with severe pain, swelling, and increased local heat in the proximal area of the right knee 3 weeks after she first noticed discomfort. Magnetic resonance imaging showed persistent osteomyelitis of the distal metaphysis and diaphysis of the femur with a multifocal intraosseous abscess pocket. An incision and drainage of the abscess were conducted. The tissue culture, fungus culture, acid fast bacillus (AFB) culture, AFB smear, and tuberculosis polymerase chain reaction test results were negative. A pathologic examination confirmed the presence of actinomycosis. The patient was successfully treated with intravenous penicillin G for 8 weeks followed by oral amoxicillin-clavulanate for 6 weeks with repeated surgical debridement and drainage. After a 5-year follow up, the patient had no signs of recurring infection or complications and she had full range of movement in the affected knee.

CONCLUSIONS

Although rare, actinomycotic osteomyelitis can occur in healthy people. Furthermore, actinomycotic osteomyelitis is easily misdiagnosed as tuberculosis in areas with a high prevalence of tuberculosis. To detect and identify the bacteria accurately, pathologic examination should be performed as well as culture tests, because the probability for culture confirmation of actinomycosis is quite low. The initial treatment is vital to a successful outcome without ostectomy or amputation.

Acute periprosthetic joint infection due to Fusobacterium nucleatum in a non-immunocompromised patient. Failure using a Debridement, Antibiotics + Implant retention approach

Fusobacterium nucleatum is an obligately anaerobic gram-negative rod, a component of the microbiome of the oropharynx and the gastrointestinal and urogenital tracts, causing an array of human infections which often include periodontal pathologies. As far as we know, there are no previous publications about acute periprosthetic joint infection due to Fusobacterium sp.; we report the first case in the medical literature of an aggressive, acute knee prosthetic infection due to F. nucleatum in a non-immunocompromised patient, unsuccessfully treated with a DAIR approach (Debridement + Antibiotics + Implant Retention).

Fusobacterium emphysematous pyomyositis with necrotizing fasciitis of the leg presenting as compartment syndrome: a case report

Background

Fusobacterium necrophorum is a common agent of disease in humans, but the occurrence of primary infections outside the head and neck area is extremely rare. While infection with Fusobacterium necrophorum has a rather benign course above the thorax, the organism is capable of producing very severe disease when located in unusual sites, including various forms of septic thrombophlebitis. No infections of the leg have been documented before; thus, antibiotic coverage for Fusobacterium is currently not recommended in this area.

Case presentation

A 50-year-old homeless African-American man presented complaining of severe pain in his right lower extremity. A clinical workup was consistent with emphysematous pyomyositis and compartment syndrome; he received limb-saving surgical intervention. The offending organism was identified as Fusobacterium necrophorum, and the antibiotic coverage was adjusted accordingly.

Conclusions

Bacteria typically involved in necrotizing infections of the lower extremity include Group A ß-hemolytic Streptococcus, Clostridium perfringens, and common anaerobic bacteria (Bacteroides, Peptococcus, and Peptostreptococcus). This case report presents a case of gas gangrene of the leg caused by Fusobacterium necrophorum, the first such case reported. Fusobacterium should now be included in the differential diagnosis of necrotizing fasciitis of the extremities.

The Influence of Dams on Malaria Transmission in Sub-Saharan Africa

The construction of dams in sub-Saharan Africa is pivotal for food security and alleviating poverty in the region. However, the unintended adverse public health implications of extending the spatial distribution of water infrastructure are poorly documented and may minimize the intended benefits of securing water supplies. This paper reviews existing studies on the influence of dams on the spatial distribution of malaria parasites and vectors in sub-Saharan Africa. Common themes emerging from the literature were that dams intensified malaria transmission in semi-arid and highland areas with unstable malaria transmission but had little or no impact in areas with perennial transmission. Differences in the impacts of dams resulted from the types and characteristics of malaria vectors and their breeding habitats in different settings of sub-Saharan Africa. A higher abundance of a less anthropophilic Anopheles arabiensis than a highly efficient vector A. gambiae explains why dams did not increase malaria in stable areas. In unstable areas where transmission is limited by availability of water bodies for vector breeding, dams generally increase malaria by providing breeding habitats for prominent malaria vector species. Integrated vector control measures that include reservoir management, coupled with conventional malaria control strategies, could optimize a reduction of the risk of malaria transmission around dams in the region.

Gastrointestinal Variant of Lemierre Syndrome: Fusobacterium nucleatum Bacteremia-Associated Hepatic Vein Thrombosis: a Case Report and Literature Review

Fusobacterium nucleatum is a gram-negative bacillius commonly found in oropharynx and is traditionally associated with Lemierre syndrome, which is characterized by history of recent oropharyngeal infection, internal jugular vein thrombosis, and isolation of anaerobic pathogens, mainly Fuosobacterium necrophorum. However, recent evidence indicated that F. nucleatum is also a normal resident of human gut. Less than a dozen of case reports had linked F. nucleatum to gastrointestinal variant of Lemierre syndrome with portal vein thrombosis. However, F. nucleatum bacteremia-associated hepatic vein thrombosis is very rare. We report a case of a 73-year-old man who had hepatic vein thrombosis associated with F. nucleatum bacteremia, most likely from subclinical primary infection affecting the lower gastrointestinal tract. The underlying pathophysiology and treatment options are discussed here. With rapid increase in reporting of Lemierre syndrome, this case deserves particular attention from clinicians.

Inhibition of the MurA enzyme in Fusobacterium nucleatum by potential inhibitors identified through computational and in vitro approaches

Inhibition of MurA in open conformation by orientin and in closed conformation by quercetin-3-O-d-glucuronide with efficient inhibitory constant values.

Olecranon Osteomyelitis due to Actinomyces meyeri: Report of a Culture-Proven Case

Actinomyces meyeri is a Gram positive, strict anaerobic bacterium, which was first described by Meyer in 1911. Primary actinomycotic osteomyelitis is rare and primarily affects the cervicofacial region, including mandible. We present an unusual case of osteomyelitis of a long bone combined with myoabscess due to A. meyeri. A 70-year-old man was admitted for pain and pus discharge of the right elbow. Twenty-five days before admission, he had hit his elbow against a table. MRI of the elbow showed a partial tear of the distal triceps tendon and myositis. He underwent open debridement and partial bone resection for the osteomyelitis of the olecranon. Biopsy showed no sulfur granules, but acute and chronic osteomyelitis. The excised tissue grew A. meyeri and Peptoniphilus asaccharolyticus. Intravenous ceftriaxone was administered and switched to oral amoxicillin. Infection of the extremities of actinomycosis often poses diagnostic difficulties, but it should not be neglected even when the characteristic pathologic findings are not present.

Target identification in Fusobacterium nucleatum by subtractive genomics approach and enrichment analysis of host-pathogen protein-protein interactions

Background

Fusobacterium nucleatum, a well studied bacterium in periodontal diseases, appendicitis, gingivitis, osteomyelitis and pregnancy complications has recently gained attention due to its association with colorectal cancer (CRC) progression. Treatment with berberine was shown to reverse F. nucleatum-induced CRC progression in mice by balancing the growth of opportunistic pathogens in tumor microenvironment. Intestinal microbiota imbalance and the infections caused by F. nucleatum might be regulated by therapeutic intervention. Hence, we aimed to predict drug target proteins in F. nucleatum, through subtractive genomics approach and host-pathogen protein-protein interactions (HP-PPIs). We also carried out enrichment analysis of host interacting partners to hypothesize the possible mechanisms involved in CRC progression due to F. nucleatum.

Results

In subtractive genomics approach, the essential, virulence and resistance related proteins were retrieved from RefSeq proteome of F. nucleatum by searching against Database of Essential Genes (DEG), Virulence Factor Database (VFDB) and Antibiotic Resistance Gene-ANNOTation (ARG-ANNOT) tool respectively. A subsequent hierarchical screening to identify non-human homologous, metabolic pathway-independent/pathway-specific and druggable proteins resulted in eight pathway-independent and 27 pathway-specific druggable targets. Co-aggregation of F. nucleatum with host induces proinflammatory gene expression thereby potentiates tumorigenesis. Hence, proteins from IBDsite, a database for inflammatory bowel disease (IBD) research and those involved in colorectal adenocarcinoma as interpreted from The Cancer Genome Atlas (TCGA) were retrieved to predict drug targets based on HP-PPIs with F. nucleatum proteome. Prediction of HP-PPIs exhibited 186 interactions contributed by 103 host and 76 bacterial proteins. Bacterial interacting partners were accounted as putative targets. And enrichment analysis of host interacting partners showed statistically enriched terms that were in positive correlation with CRC, atherosclerosis, cardiovascular, osteoporosis, Alzheimer’s and other diseases.

Conclusion

Subtractive genomics analysis provided a set of target proteins suggested to be indispensable for survival and pathogenicity of F. nucleatum. These target proteins might be considered for designing potent inhibitors to abrogate F. nucleatum infections. From enrichment analysis, it was hypothesized that F. nucleatum infection might enhance CRC progression by simultaneously regulating multiple signaling cascades which could lead to up-regulation of proinflammatory responses, oncogenes, modulation of host immune defense mechanism and suppression of DNA repair system.

Electronic supplementary material

The online version of this article (doi:10.1186/s12866-016-0700-0) contains supplementary material, which is available to authorized users.

Fusobacterium nucleatum infections: clinical spectrum and bacteriological features of 78 cases

PURPOSE

Few series describe the clinical spectrum of Fusobacterium spp. infections. Among them, fewer discuss F. nucleatum, even though there are many clinical cases.

METHODS

We performed a retrospective study over 8 years (from 2007 to 2014) in Limoges University Hospital, France, to assess clinical and bacteriological aspects of infections due to F. nucleatum.

RESULTS

Eighty-one patients with F. nucleatum positive cultures were included in this study, irrespective of sample origin. Abscesses (n = 43), bacteraemia (n = 18) and bone infections (n = 8) were the most common types of infections, Abscesses were found in various organs (mostly skin, brain, pleura, liver). Co-morbidities were found in 38 patients (47 %) with neoplasia, diabetes, and alcoholism and history of smoking. There were more neoplasms in patients with bacteraemia than in patients with abscesses (p = 0.007). In 51 cases (65.4 %), infection was polymicrobial, either during bacteraemia or abscesses. Main associations were with Streptococcus spp., Peptostreptococcus spp. and/or Prevotella spp. The sources of infection, when found, were either dental or gastrointestinal. All isolates were susceptible to penicillin, clindamycin and metronidazole.

CONCLUSIONS

Infections involving F. nucleatum are uncommon and potentially severe, with many abscesses requiring surgery. Bacteraemia was mainly associated with co-morbidities such as cancer. Polymicrobial infections were very common and there is probably interaction and/or synergy between F. nucleatum and some other commensal bacteria to cause infections and abscesses.

Fusobacterium nucleatum Osteomyelitis of the Femur in a Patient with Hereditary Hemorrhagic Telangiectasia: A Case Report

CASE

Hereditary hemorrhagic telangiectasia (HHT), also known as Osler-Weber-Rendu syndrome, is an often overlooked cause of orthopaedic-related infections despite a well-accepted association in the literature. We present the case of a forty-seven-year-old man with HHT who developed femoral osteomyelitis and a subsequent pathologic femoral fracture from a rare bacterial species associated with HHT.

CONCLUSION

Patients with HHT and extremity pain should be carefully evaluated for orthopaedic infections. If an orthopaedic infection is suspected, fastidious organisms should be considered as a possible etiologic agent. PCR (polymerase chain reaction) is helpful when organisms cannot be isolated from traditional culture media.

Prevalence of Actinomyces spp. in patients with chronic periodontitis

This study investigated the prevalence of Actinomyces spp. in shallow, deep and very deep pockets of patients with chronic periodontitis compared to healthy controls and correlated the results with clinical status. Twenty patients with chronic periodontitis and 15 healthy subjects were enrolled in this study. Clinical indices were recorded in a six-point measurement per tooth. From each patient samples of supra and subgingival plaque were taken separately from teeth with shallow, deep and very deep pockets. Samples of supragingival plaque and sulcular microflora were collected from the healthy subjects. All the samples were cultivated on different media at 37̊C in an anaerobic atmosphere for 7 days. All the suspect colonies were identified using a rapid ID 32 A system (bioMèrieux) and MALDI-TOF-MS analysis using an Autoflex II Instrument (Bruker Daltonics) together with in house developed identification software and a reference spectra database. A total of 977 strains were identified as Actinomyces. Actinomyces naeslundii/oris/johnsonii (430 isolates) was the most prevalent species and was found in all patients and in almost all of the healthy subjects. Significant differences (p=0.003) between the groups were found for Actinomyces odontolyticus/meyeri and Actinomyces israelii which were associated with periodontitis patients. Actinomyces dentalis was found in higher percentage (p=0.015) in the periodontitis group. Actinomyces gerencseriae and Actinomyces massiliensis were significantly more often found supragingivally than subgingivally (p=0.004, p=0.022, respectively) in the periodontitis group. Whether some Actinomyces species, definitely important plaque formers, are actively involved in the pathogenicity of chronic periodontitis needs further investigation.

Actinomyces and related organisms in human infections

Actinomyces israelii has long been recognized as a causative agent of actinomycosis. During the past 3 decades, a large number of novel Actinomyces species have been described. Their detection and identification in clinical microbiology laboratories and recognition as pathogens in clinical settings can be challenging. With the introduction of advanced molecular methods, knowledge about their clinical relevance is gradually increasing, and the spectrum of diseases associated with Actinomyces and Actinomyces-like organisms is widening accordingly; for example, Actinomyces meyeri, Actinomyces neuii, and Actinomyces turicensis as well as Actinotignum (formerly Actinobaculum) schaalii are emerging as important causes of specific infections at various body sites. In the present review, we have gathered this information to provide a comprehensive and microbiologically consistent overview of the significance of Actinomyces and some closely related taxa in human infections.

Coinfection of Fusobacterium nucleatum and Actinomyces israelii in mastoiditis diagnosed by next-generation DNA sequencing

Some bacterial infections involve potentially complex mixtures of species that can now be distinguished using next-generation DNA sequencing. We present a case of mastoiditis where Gram stain, culture, and molecular diagnosis were nondiagnostic or discrepant. Next-generation sequencing implicated coinfection of Fusobacterium nucleatum and Actinomyces israelii, resolving these diagnostic discrepancies.

Suppuration-associated bacteria in patients with chronic and aggressive periodontitis

BACKGROUND

Suppuration (SUP) on probing may be an indication of active periodontal breakdown. The aim of the present study is to analyze which subgingival species are associated with SUP in patients with chronic (CP) and aggressive (AgP) periodontitis.

METHODS

A total of 156 patients with CP and 66 with AgP were submitted to full-mouth periodontal examination and subgingival biofilm sampling (14 sites/patient). The counts of 44 bacterial species were determined by checkerboard. Comparisons between groups and sites were analyzed by the Mann-Whitney and Wilcoxon tests, respectively. Associations between frequency of SUP and bacterial species were analyzed by the Spearman correlation coefficient.

RESULTS

The prevalence of SUP in patients with CP was 24.4%, and in patients with AgP it was 30.3%, and the percentage of SUP sites in the groups was 5.72% ± 1.06% and 6.96% ± 1.70%, respectively (P >0.05). SUP sites from patients with CP had significantly higher counts of Veillonella parvula, Dialister pneumosintes, Tannerella forsythia, and Prevotella nigrescens than SUP sites from patients with AgP (P <0.005). Significant positive correlations between high frequency of SUP and high levels of Actinomyces spp, Streptococcus spp., members of the orange complex, Acinetobacter baumannii, and Pseudomonas aeruginosa were observed in patients with CP (P <0.05). In patients with AgP, Actinomyces oris, Propionibacterium acnes, P. aeruginosa, Staphylococcus aureus, and Streptococcus sanguinis were positively associated with SUP, whereas Prevotella intermedia presented a negative association with SUP (P <0.05).

CONCLUSIONS

SUP sites from patients with CP harbored significantly higher counts of several periodontal species than SUP sites from patients with AgP. Actinomyces spp., Streptococcus spp., members of the orange complex, T. forsythia, and certain non-oral pathogens were associated with a high number of sites with SUP.