Fusobacterial infections in children

Overview of anaerobic infections in children and their treatment

Anaerobic bacteria can cause many infections in children. Because they predominant in the normal human skin and mucous membranes bacterial flora, they are often associated with bacterial infections that originate from these sites. They are difficult to isolate from infectious sites, and are frequently missed. Anaerobic infections can occur in all body sites, including the central nervous system, oral cavity, head and neck, chest, abdomen, pelvis, skin, and soft tissues. Anaerobes colonize the newborn after birth and have been isolated in several types of neonatal infections. These include cellulitis of the site of fetal monitoring, neonatal aspiration pneumonia, bacteremia, conjunctivitis, omphalitis, and infant botulism. Management of anaerobic infection is challenging because of the slow growth of these bacteria, by their polymicrobial nature and by the growing antimicrobial resistance of anaerobic. Antimicrobial therapy may be the only treatment required, and may also be an adjunct to a surgical approach. Polymicrobial aerobic-anaerobic infection generally requires delivering antimicrobial therapy effective against all pathogens. The antibiotics with the greatest activity against anaerobes include carbapenems, beta-lactam/beta-lactamase inhibitor combinations, metronidazole, and chloramphenicol. Antimicrobial resistance is growing among anaerobic bacteria. The major increased in resistance have been reported with clindamycin, cephamycins, and moxifloxacin against Bacteroides fragilis group and related strains. Resistance patterns vary between different geographic areas and medical facilities.

A single-center, retrospective study of hospitalized patients with lower respiratory tract infections: clinical assessment of metagenomic next-generation sequencing and identification of risk factors in patients

INTRODUCTION

Lower respiratory tract infections(LRTIs) in adults are complicated by diverse pathogens that challenge traditional detection methods, which are often slow and insensitive. Metagenomic next-generation sequencing (mNGS) offers a comprehensive, high-throughput, and unbiased approach to pathogen identification. This retrospective study evaluates the diagnostic efficacy of mNGS compared to conventional microbiological testing (CMT) in LRTIs, aiming to enhance detection accuracy and enable early clinical prediction.

METHODS

In our retrospective single-center analysis, 451 patients with suspected LRTIs underwent mNGS testing from July 2020 to July 2023. We assessed the pathogen spectrum and compared the diagnostic efficacy of mNGS to CMT, with clinical comprehensive diagnosis serving as the reference standard. The study analyzed mNGS performance in lung tissue biopsies and bronchoalveolar lavage fluid (BALF) from cases suspected of lung infection. Patients were stratified into two groups based on clinical outcomes (improvement or mortality), and we compared clinical data and conventional laboratory indices between groups. A predictive model and nomogram for the prognosis of LRTIs were constructed using univariate followed by multivariate logistic regression, with model predictive accuracy evaluated by the area under the ROC curve (AUC).

RESULTS

(1) Comparative Analysis of mNGS versus CMT: In a comprehensive analysis of 510 specimens, where 59 cases were concurrently collected from lung tissue biopsies and BALF, the study highlights the diagnostic superiority of mNGS over CMT. Specifically, mNGS demonstrated significantly higher sensitivity and specificity in BALF samples (82.86% vs. 44.42% and 52.00% vs. 21.05%, respectively, p < 0.001) alongside greater positive and negative predictive values (96.71% vs. 79.55% and 15.12% vs. 5.19%, respectively, p < 0.01). Additionally, when comparing simultaneous testing of lung tissue biopsies and BALF, mNGS showed enhanced sensitivity in BALF (84.21% vs. 57.41%), whereas lung tissues offered higher specificity (80.00% vs. 50.00%). (2) Analysis of Infectious Species in Patients from This Study: The study also notes a concerning incidence of lung abscesses and identifies Epstein-Barr virus (EBV), Fusobacterium nucleatum, Mycoplasma pneumoniae, Chlamydia psittaci, and Haemophilus influenzae as the most common pathogens, with Klebsiella pneumoniae emerging as the predominant bacterial culprit. Among herpes viruses, EBV and herpes virus 7 (HHV-7) were most frequently detected, with HHV-7 more prevalent in immunocompromised individuals. (3) Risk Factors for Adverse Prognosis and a Mortality Risk Prediction Model in Patients with LRTIs: We identified key risk factors for poor prognosis in lower respiratory tract infection patients, with significant findings including delayed time to mNGS testing, low lymphocyte percentage, presence of chronic lung disease, multiple comorbidities, false-negative CMT results, and positive herpesvirus affecting patient outcomes. We also developed a nomogram model with good consistency and high accuracy (AUC of 0.825) for predicting mortality risk in these patients, offering a valuable clinical tool for assessing prognosis.

CONCLUSION

The study underscores mNGS as a superior tool for lower respiratory tract infection diagnosis, exhibiting higher sensitivity and specificity than traditional methods.

Unveiling the etiology of peritonsillar abscess using next generation sequencing

BACKGROUND

Peritonsillar abscess (PTA) is a severe deep neck space infection with an insufficiently characterized bacterial etiology. We aimed to reveal the bacteria associated with PTA applying next generation sequencing (NGS). Tonsil biopsies and pus samples of 91 PTA patients were analysed applying NGS method.

RESULTS

Over 400 genera and 800 species belonging to 34 phyla were revealed. The most abundant species in both sample types were Streptococcus pyogenes, Fusobacterium necrophorum and Fusobacterium nucleatum. When present, S. pyogenes was normally a predominant species, although it was recovered as a minor population in some samples dominated by F. nucleatum and occasionally F. necrophorum. S. pyogenes and F. necrophorum were the predominant species (> 10% in a community) in 28 (31%) pus samples, while F. nucleatum in 21 (23%) and S. anginosus in 8 (9%) pus samples. We observed no substantial differences between the microbial findings in pus and tonsil biopsies.

CONCLUSIONS

The most probable causative agents of PTA according to our NGS-study include Streptococcus pyogenes, Fusobacterium necrophorum and Fusobacterium nucleatum. Some other streptococci (S. anginosus) and anaerobes (Prevotella, Porphyromonas) may contribute to the infection as well. Pus of the peritonsillar abscess is more representative specimen for microbiological examination than the tonsillar tissue. Our results are important in the context of optimizing the handling of the PTA patients.

Fusobacterial Pelvic Osteomyelitis with Brodie's Abscess in a 10-Year-Old Boy Requiring Surgical Evacuation: A Case Report

CASE

A 10-year-old boy presented with pain in the lateral hip and buttock area and fever. Magnetic resonance imaging revealed osteomyelitis of the pelvis with extensive Brodie's abscess (2.6 × 4.5 × 10.0 cm) continuing into the pelvic cavity. Surgical evacuation through the ilioinguinal approach was performed. In prolonged culture and in polymerase chain reaction of pus, the Fusobacterium nucleatum was found.

CONCLUSION

Pelvic osteomyelitis caused by Fusobacterium is very rare. In this case, surgical treatment was required after conservative treatment with antibiotics was ineffective.

Determination of the Role of Fusobacterium Nucleatum in the Pathogenesis in and Out the Mouth

INTRODUCTION

One of the most important types of microorganisms in the oral cavity in both healthy and non-healthy individuals is Fusobacterium nucleatum. Although present as a normal resident in the oral cavity, this Gram-negative pathogen is dominant in periodontal disease and it is involved in many invasive infections in the population, acute and chronic inflammatory conditions, as well as many adverse events with a fatal outcome.

AIM

To determine the role of F. nucleatum in the development of polymicrobial biofilms thus pathogenic changes in and out of the oral media.

MATERIAL AND METHOD

A systematic review of the literature concerning the determination and role of F. nucleatum through available clinical trials, literature reviews, original research and articles published electronically at Pub Med and Google Scholar.

CONCLUSION

The presence of Fusobacterium nucleatum is commonly associated with the health status of individuals. These anaerobic bacteria plays a key role in oral pathological conditions and has been detected in many systemic disorders causing complex pathogenethic changes probably due to binding ability to various cells thus several virulence mechanisms. Most common diseases and conditions in the oral cavity associated with F.nucleatum are gingivitis (G), chronic periodontitis (CH), aggressive periodontitis (AgP), endo-periodental infections (E-P), chronic apical periodontitis (PCHA). The bacterium has been identified and detected in many systemic disorders such as coronary heart disease (CVD) pathological pregnancy (P); polycystic ovary syndrome (PCOS), high-risk pregnancy (HRP), colorectal cancer (CRC); pre-eclampsia (PE); rheumatoid arthritis (RA); osteoarthritis (OA).

Oral and pulmonary necrobacillosis in a juvenile reticulated giraffe

A 1-mo-old reticulated giraffe had progressive anorexia and died at the Ordos Zoo. Autopsy revealed necrotic stomatitis with severe bilateral necroulcerative lesions at the base of the tongue and of the cheeks near the commissures of the mouth. There was also severe bilateral confluent bronchopneumonia with a pronounced bronchial pattern and multifocal fibrinous pleuritis. Histologically, there was serofibrinous-suppurative bronchopneumonia with necrosuppurative bronchiolitis and necrotic arteritis. Filamentous bacteria with morphology consistent with Fusobacterium necrophorum were observed at the advancing edge of the necrotic tissue in the tongue and cheeks, as well as in the affected alveolar spaces and bronchioles. Aggregates of slender, gram-negative, rod-like or filamentous bacteria were identified in the lung impression smear. PCR results of 16S rDNA of the tongue and lung lesions had 100% homology to the F. necrophorum subsp. funduliforme B35 sequence (EF447425.1). The gross, histologic, Gram stain, and PCR product sequencing features in our case were consistent with oral and pulmonary necrobacillosis in ruminants, a rare disease of giraffes.

Osteomyelitis of the Distal Phalanx of the Thumb due to Parvimonas micra and Fusobacterium nucleatum: A Case Report

We herein report a case of osteomyelitis of the distal phalanx of the thumb of a 55-year-old man caused by Parvimonas micra and Fusobacterium nucleatum. Osteomyelitis often occurs in long bones and rarely occurs in the bones of the fingers. In addition, osteomyelitis of the finger frequently occurs after trauma or surgery, and blood-borne infection is very rare. P. micra and F. nucleatum, normal flora of the oral cavity, are very rare pathogenic bacteria of osteomyelitis except in periodontal disease, and there are no previous reports regarding the occurrence of osteomyelitis due to P. micra and F. nucleatum in the finger bones.

Anaerobic Necrotizing Pneumonia: Another Potential Life-threatening Complication of Vaping?

An adolescent girl with a history of frequent electronic cigarette use of nicotine was hospitalized with severe necrotizing pneumonia. Blood cultures obtained before the administration of empirical broad-spectrum intravenous antibiotics had positive results for the growth of Fusobacterium necrophorum The pathogen is an uncommon but well-known cause of anaerobic pneumonia with unique features that are collectively referred to as Lemierre syndrome or postanginal sepsis. The syndrome begins as a pharyngeal infection. Untreated, the infection progresses to involve the ipsilateral internal jugular vein, resulting in septic thrombophlebitis with direct spread from the neck to the lungs causing multifocal necrotizing pneumonia. The teenager we present in this report had neither a preceding pharyngeal infection nor Doppler ultrasonographic evidence for the presence of deep neck vein thrombi, leading us to explore alternative mechanisms for her pneumonia. We propose the possibility that her behavior of frequent vaping led to sufficient pharyngeal irritation such that F necrophorum colonizing her oropharynx was inhaled directly into her lungs during electronic cigarette use. Preexisting, but not yet recognized, vaping-related lung injury may have also contributed to her risk of developing the infection. The patient was hospitalized for 10 days. At follow-up one month later, she still became short of breath with minimal exertion.

Brain Abscess Associated with Polymicrobial Infection after Intraoral Laceration: A Pediatric Case Report

Brain abscesses, infections within the brain parenchyma, can arise as complications of various conditions including infections, trauma, and surgery. However, brain abscesses due to polymicrobial organisms have rarely been reported in children. We herein report a case of a 9-year-old girl with unresolved congenital cyanotic heart disease (CCHD) presenting with right hemiplegia who was diagnosed with brain abscess caused by Streptococcus intermedius, Parvimonas micra, and Fusobacterium nucleatum after oropharyngeal injury. She was treated with intravenous antimicrobial therapy, drainage under craniotomy, and antiedema therapy with glycerol and goreisan, which led to the improvement of right hemiplegia to baseline; she was discharged following eight weeks of intravenous antimicrobial therapy. The clinical diagnosis of the brain abscess was difficult due to the nonspecific presentation, highlighting the importance of cranial imaging without haste in patients at increased risk for brain abscesses such as those with CCHD, presenting with fever in the absence of localizing symptoms or fever, accompanied with abnormal neurological findings.

Substrate recognition by bacterial solute-binding protein is responsible for import of extracellular hyaluronan and chondroitin sulfate from the animal host

Glycosaminoglycans (GAGs) such as hyaluronan and chondroitin in animal extracellular matrices contain disaccharide-repeating units. In a Gram-negative pathogenic Streptobacillus moniliformis, which belongs to Fusobacteria phylum and resides in rodent oral cavities, the solute-binding protein (Smon0123)-dependent ATP-binding cassette transporter imports unsaturated hyaluronan/chondroitin disaccharides into the cytoplasm after GAG lyase-dependent depolymerization. Here we show substrate recognition of unsaturated hyaluronan disaccharide by Smon0123. Moreover, Smon0123 exhibited no affinity for unsaturated chondroitin disaccharides containing three sulfate groups, distinct from non-sulfated, mono-sulfated, and di-sulfated chondroitin disaccharides previously identified as substrates. Crystal structure of Smon0123 with unsaturated hyaluronan disaccharide demonstrates that several residues, including Trp284 and Glu410, are crucial for binding to unsaturated hyaluronan/chondroitin disaccharides, whereas arrangements of water molecules at binding sites are found to be substrate dependent through comparison with substrate-bound structures determined previously. These residues are well conserved in Smon0123-like proteins of fusobacteria, and probably facilitate the fusobacterial residence in hyaluronan-rich oral cavities.

Lemierre's Syndrome with Septic Shock Caused by Fusobacterium Necrophorum

Fusobacterium necrophorum infections are rare. We report a 15-year-old male who presented with tachycardia, nausea, vomiting, diarrhoea and ankle pain. He rapidly deteriorated requiring ventilation and vasopressors. Imaging of his thorax showed airspace consolidation, pulmonary cavitations and empyema. The ankle required drainage of purulent material. A thrombus in his internaljugular vein (Lemierre's syndrome) and an abscess in his obturator internus were subsequently found. Fusobacterium necrophorum was identified in blood culture on day nine. The patient recovered with antibiotics and surgical interventions for empyema and septic arthritis. Fusobacterium necrophorum should be a suspected pathogen in septic shock complicated by metastatic abscess formation.

Fusobacterium necrophorum as an Emerging Pathogen of Acute Mastoiditis

BACKGROUND

Recent reports have reported an increase in the incidence of acute mastoiditis because of Fusobacterium necrophorum. However, the crude incidence and the specific clinical and laboratory characteristics of F. necrophorum mastoiditis in children have not been described. Our aim was to describe these features to identify high-risk patients.

METHODS

The electronic medical records of all children with acute mastoiditis at a tertiary medical center between July 2011 and December 2015 were analyzed. Using a stepwise logistic regression to identify independent risk factors for F. necrophorum, we formulated a predictive model.

RESULTS

F. necrophorum was identified in 13% (19/149) of mastoiditis cases with an identifiable agent. Its incidence increased 7-fold from 2.8% in 2012 to 20.4% in 2015 (P = 0.02). F. necrophorum infection had unique clinical, laboratory and prognostic features. The vast majority had complications and underwent surgical intervention. The predictive model used 4 parameters to define high-risk patients for F. necrophorum infection at admission: females, winter/spring season, prior antibiotic treatment and a C-reactive protein value >20 mg/dL (area under receiver operating characteristic curve 0.929).

CONCLUSIONS

Clinicians should be aware of the increasing incidence of F. necrophorum mastoiditis and consider anaerobic cultures and specific anaerobic coverage in high-risk patients.

A bacterial ABC transporter enables import of mammalian host glycosaminoglycans

Glycosaminoglycans (GAGs), such as hyaluronan, chondroitin sulfate, and heparin, constitute mammalian extracellular matrices. The uronate and amino sugar residues in hyaluronan and chondroitin sulfate are linked by 1,3-glycoside bond, while heparin contains 1,4-glycoside bond. Some bacteria target GAGs as means of establishing colonization and/or infection, and bacterial degradation mechanisms of GAGs have been well characterized. However, little is known about the bacterial import of GAGs. Here, we show a GAG import system, comprised of a solute-binding protein (Smon0123)-dependent ATP-binding cassette (ABC) transporter, in the pathogenic Streptobacillus moniliformis. A genetic cluster responsible for depolymerization, degradation, and metabolism of GAGs as well as the ABC transporter system was found in the S. moniliformis genome. This bacterium degraded hyaluronan and chondroitin sulfate with an expression of the genetic cluster, while heparin repressed the bacterial growth. The purified recombinant Smon0123 exhibited an affinity with disaccharides generated from hyaluronan and chondroitin sulfate. X-ray crystallography indicated binding mode of Smon0123 to GAG disaccharides. The purified recombinant ABC transporter as a tetramer (Smon0121-Smon0122/Smon0120-Smon0120) reconstructed in liposomes enhanced its ATPase activity in the presence of Smon0123 and GAG disaccharides. This is the first report that has molecularly depicted a bacterial import system of both sulfated and non-sulfated GAGs.

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.

Fusobacterium nucleatum Osteomyelitis in 3 Previously Healthy Children: A Case Series and Review of the Literature

Fusobacterium nucleatum is a rare cause of monomicrobial osteomyelitis in children. We describe the cases of 3 children with F. nucleatum osteomyelitis of the distal femoral epiphysis with concurrent septic arthritis and review 6 other cases reported in the literature. Our report emphasizes the importance of maintaining a high index of suspicion for anaerobic osteomyelitis, given its atypical presentation and the unique growth requirements of anaerobic bacteria.

Fusobacterial head and neck infections in children

Fusobacterium species are increasingly recognized as a cause of head and neck infections in children. These infections include acute and chronic otitis, sinusitis, mastoiditis, and tonsillitis; peritonsillar and retropharyngeal abscesses; Lemierre syndrome; post-anginal cervical lymphadenitis; and periodontitis. They can also be involved in brain abscess and bacteremia associated with head and neck infections. This review describes the clinical spectrum of head and neck fusobacterial infection in children and their management.

Infections caused by Fusobacterium in children: a 14-year single-center experience

PURPOSE

This study aimed at reviewing our experience with infections caused by Fusobacterium in children.

METHODS

A retrospective analysis of medical records of children admitted to Hadassah-Hebrew University Medical Center from 2000 to 2013, in whom Fusobacterium spp. was identified in any specimen.

RESULTS

A total of 22 patients (males = 12) at a mean ± SE age of 5 ± 1 (range 1-17) years, were identified. The most common complication was abscess formation (n = 11, 50 %). Eight children (36.4 %) had intracranial complications, including brain abscess (n = 4), meningitis (n = 4) and cerebral sinus vein thrombosis (CSVT, n = 5). Seventeen children (77 %) had bacteremia. Primary site of infection was otogenic (n = 9), oropharyngeal (n = 7), respiratory (n = 2), sinuses (n = 2), intra-abdominal (n = 1) and mucositis (n = 1). Fourteen cases were caused by Fusobacterium necrophorum, including four cases with CSVT, 7/8 cases of mastoiditis, four of them with subperiosteal abscess formation; all four cases with meningitis and two brain abscesses. Fifteen (68 %) patients required surgical intervention and 3 (14 %) received anti-coagulation therapy. Excluding one patient with overwhelming sepsis with fatal outcome, all patients recovered.

CONCLUSIONS

Fusobacterium infections in children can cause a diverse spectrum of disease and is associated with high rates of abscess formation and intracranial complications. Although Fusobacterium nucleatum is abundant in the oral cavity, F. necrophorum is the main pathogen that causes severe infections in healthy children.

Pyogenic liver abscess caused by Fusobacterium in a 21-year-old immunocompetent male

A 21-year-old male with no significant past medical history, presented with right upper quadrant (RUQ) abdominal pain along with fevers and chills. Lab work revealed leukocytosis, anemia, and slightly elevated alkaline phosphatase. Viral serology for hepatitis B virus, hepatitis C virus, and human immunodeficiency virus were negative and he was immunocompetent. Computed tomography imaging revealed hepatic abscesses, the largest measuring 9.5 cm. Empiric antibiotics were started and percutaneous drains were placed in the abscesses. Anaerobic cultures from the abscesses grew Fusobacterium nucleatum. This is a gram negative anaerobic bacteria; a normal flora of the oral cavity. Fusobacterium is most commonly seen in Lemiere’s disease, which is translocation of oral bacteria to the internal jugular vein causing a thrombophlebitis and subsequent spread of abscesses. Our patient did not have Lemiere’s, and is the first case described of fusobacterium pyogenic liver abscess in a young immunocompetent male with good oral hygiene. This case was complicated by sepsis, empyema, and subsequent abscesses located outside the liver. These abscesses’ have the propensity to flare abruptly and can be fatal. This case not only illustrates fusobacterium as a rare entity for pyogenic liver abscess, but also the need for urgent diagnosis and treatment. It is incumbent on physicians to diagnose and drain any suspicious hepatic lesions. While uncommon, such infections may develop without any overt source and can progress rapidly. Prompt drainage with antibiotic therapy remains the cornerstone of therapy.

Subacute osteomyelitis of the femur due to Fusobacterium nucleatum in a 7-year-old boy

Subacute hematogenous osteomyelitis is an insidious infection, which commonly has a delayed diagnosis. We describe the case of a 7-year-old boy with subacute osteomyelitis, which was initially considered to be a bone tumor. Infection should be considered in all cases of bone pain, especially in children, even in the absence of typical systemic features of inflammation.

Endobronchial lesion due to pulmonary Fusobacterium nucleatum infection in a child

Clinically significant infections due to the members of the genus Fusobacterium are rare. The clinical manifestations of pulmonary Fusobacterium nucleatum infections range from simple aspiration pneumonia to severe diseases as necrotizing pneumonia, lung abscess, and empyema. Endobronchial lesions and obstructions are rarely seen in children and are often a misdiagnosed result in delay of definitive treatment. Here, we report a case of endobronchial lesion due to pulmonary F. nucleatum infection in an entirely healthy child before illness. This is the first case reported in the literature of endobronchial lesion due to pulmonary F. nucleatum infection.

Gradenigo's syndrome: is fusobacterium different? Two cases and review of the literature

Gradenigo's syndrome is a rare but life threatening complication of acute otitis media (AOM), which includes a classic triad of otitis media, deep facial pain and ipsilateral abducens nerve paralysis. The incidence of Fusobacterium necrophorum infections has increased in recent years. We describe two cases of Gradenigo's syndrome caused by F. necrophorum. Additional four cases were identified in a review of the literature. Gradenigo's syndrome as well as other neurologic complications should be considered in cases of complicated acute otitis media. F. necrophorum should be empirically treated while awaiting culture results.

Fusobacterial infections in children

Fusobacteria are members of the oral and gastrointestinal flora and are important potential pathogens in children. They are increasingly recognized as a cause of infections in children. These include infections of the head and neck (Lemierre syndrome, acute and chronic mastoiditis, chronic otitis and sinusitis, tonsillitis, peritonsillar and retropharyngeal abscesses, postanginal cervical lymphadenitis, periodontitis), brain, lungs, abdomen, pelvis, bones, joints, and blood. This review describes the clinical spectrum of fusobacterial infection in children and their management.

Neurologic manifestations of Fusobacterium infections in children

Fusobacterium necrophorum causes various clinical syndromes, ranging from otitis media to life-threatening Lemierre's syndrome. The purpose of this study was to review our experience with pediatric Fusobacterium infections. The medical records of all children aged 0 to 18 years who were diagnosed between 1999 and 2011 with Fusobacterium infection were reviewed. Fusobacterium was isolated from clinical samples of 27 children: blood cultures (n = 16), abscesses (n = 8), joint fluids (n = 2), and cerebrospinal fluid (n = 1). The median age at admission was 3.5 years (range, 7 months to 17 years). Eight children (30 %) had seizures at presentation. Ten children (37 %) underwent lumbar puncture. Fifteen children (56 %) underwent brain imaging, and in seven of these children, a thrombus was identified either in a sinus vein or in an internal jugular vein. The most common source of infection was otogenic in 19 (70 %) of the children. Six of the children presented in 2011. All patients recovered.

CONCLUSIONS

Neurologic manifestations are common at presentation of children with Fusobacterium infections. In young children, the most common source of infection is otogenic. Thrombotic complications are common, and imaging should be considered in all children with Fusobacterium infections arising from the head or neck region. There was a recent increase in the isolation of this bacterium, either because of better culturing techniques and increased awareness to this entity or a true increase in infections due to this organism.

Fusobacterium necrophorum mastoiditis in children - emerging pathogen in an old disease

BACKGROUND

Anaerobic bacteria are uncommon etiologic agents of acute mastoiditis in children. However, recent studies suggest an increase in the incidence of Fusobacterium necrophorum mastoid infections in the last two decades.

METHODS

A surveillance study performed over 3.5 years in a tertiary pediatric medical center identified 7 children with acute F. necrophorum mastoiditis. Clinical, laboratory, and treatment data were collected by file review.

RESULTS

Five of the 7 children presented in the last year of the study. All 7 children were less than 26 months old on admission, and none had a history of otogenic infections. All cases were characterized by significantly elevated levels of inflammatory markers. All were diagnosed as complicated mastoiditis with abscess formation. Four children had an epidural abscess, three children had evidence of osteomyelitis beyond the mastoid bone, and four children had imaging evidence of sinus vein thrombosis. All seven children required cortical mastoidectomy with ventilatory tubes insertion and two children required more than one surgical intervention. During follow-up, two children had recurrent episodes of mastoiditis due to other pathogens.

CONCLUSION

Our data support the literature suggesting that the occurrence of F. necrophorum mastoiditis among children is rising. Acute coalescent mastoiditis due to F. necrophorum is associated with a complicated course and warrants particular attention by pediatricians, infectious disease experts, and ear, nose and throat specialists.

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

Background

Fusobacterium species are uncommon causes of osteomyelitis. These organisms are normal flora of the oral cavity. Therefore, they mostly cause osteomyelitis of the head and neck. Hematogenous osteomyelitis at distant sites other than the head and neck has rarely been reported in pediatric or immunocompromised patients. Here, we report the first case of osteomyelitis of a long bone combined with a muscle abscess due to Fusobacterium nucleatum in an otherwise healthy adult.

Case presentation

A 59-year-old Korean man was admitted for pain and swelling of the right lower leg, which had been persistent for two weeks. Magnetic resonance imaging showed osteomyelitis of the right fibula with a surrounding muscle abscess of the right lower leg. Incision and drainage was performed, and repetitive tissue cultures grew F. nucleatum. In this patient, it was presumed that recurrent periodontitis caused hematogenous seeding of F. nucleatum to a distant site leading to osteomyelitis with a muscle abscess. The patient was successfully treated with intravenous ampicillin-sulbactam for three weeks and oral amoxicillin-clavulanate for eight weeks. He also underwent repeated surgical drainage. He has no evidence of recurrence after seven months of follow-up.

Conclusions

Clinicians should be aware that F. nucleatum could be the etiologic agent of hematogenous osteomyelitis of a long bone in an immunocompetent patient.

Septic arthritis and osteomyelitis in a 10-year-old boy, caused by Fusobacterium nucleatum, diagnosed with PCR/16S ribosomal bacterial DNA amplification

A 10-year-old boy presented with an atypical non-febrile septic arthritis/osteomyelitis. He was unresponsive to routine antibiotic treatment with flucloxacillin/gentamicin as the pain and fluid collection increased. Synovial fluid cultures are negative and gram stain remained negative. Only after PCR/16S ribosomal bacterial DNA amplification a Fusobacterium nucleatum could be detected, and antibiotic therapy switched to clindamycin with rapid response. Septic osteomyelitis and arthritis are relatively rare but important infections in children needing prompt treatment, and should be considered when a child complaints about joint or bone pain without prior recent trauma. Skin bacteria are the most prevalent causative organisms, whereas Fusobacteria or other anaerobic, Gram-negative microorganisms are very seldom encountered. If cultures remain negative and the patients responds insufficiently to empiric treatment, PCR/16S ribosomal bacterial DNA amplification can be useful to detect the causative microorganisms.

Characteristics and outcomes of Fusobacterium nucleatum bacteremia--a 6-year experience at a tertiary care hospital in northern Taiwan

Fusobacterium nucleatum bacteremia is critical and not well defined. To identify the clinical characteristics and outcomes, we conducted a retrospective review of hospitalized patients from January 2004 to December 2009 at a tertiary center in northern Taiwan. Fifty-seven patients were enrolled. The mean age was 58.1 years, and the mean Pitt bacteremia score was 4.7. Males predominated (59.6%), and the overall 30-day mortality rate was up to 47.4%. Malignancy was the major comorbidity (26/57, 45.6%), especially oropharyngeal and gastrointestinal cancers (19/26, 73.1%). Pneumonia (17/57, 29.8%) was the most common presentation with high rates of respiratory failure (15/17, 88.2%) and mortality (11/17, 64.7%), followed by intra-abdominal infections (7/57, 12.3%). In multivariate analysis, higher Pitt bacteremia score, nosocomial infection, anemia, and intensive care unit stay were the independent factors for 30-day mortality. Nosocomial F. nucleatum bacteremia was a significant mortality predictor independent to other parameters of disease severities.

Antimicrobial efficacy of 3 oral antiseptics containing octenidine, polyhexamethylene biguanide, or Citroxx: can chlorhexidine be replaced?

BACKGROUND

Use of oral antiseptics decreases the bacterial load in the oral cavity.

OBJECTIVE

To compare the antimicrobial activity of 3 novel oral antiseptics with that of chlorhexidine, which is considered the "gold standard" of oral hygiene.

DESIGN

Comparative in vitro study.

METHODS

Four common oral microorganisms (Streptococcus sanguinis, Streptococcus mutans, Candida albicans, and Fusobacterium nucleatum) were tested under standard conditions and at different concentrations, by use of a broth dilution assay and an agar diffusion assay and by calculating the log10 reduction factor (RF). The antimicrobial activity of each antiseptic was assessed by counting the difference in bacterial densities (ie, the log10 number of colony-forming units of bacteria) before and after the disinfection process.

RESULTS

The oral antiseptics containing octenidine (with an RF in the range of 7.1-8.24 CFU/mL) and polyhexamethylene biguanide (with an RF in the range of 7.1-8.24 CFU/mL) demonstrated antimicrobial activity comparable to that of chlorhexidine (with an RF in the range of 1.03-8.24 CFU/mL), whereas the mouth rinse containing Citroxx (Citroxx Biosciences; with an RF in the range of 0.22-1.36 CFU/mL) showed significantly weaker antimicrobial efficacy. Overall, octenidine and polyhexamethylene biguanide were more active at lower concentrations.conclusion. Oral antiseptics containing the antimicrobial agent octenidine or polyhexamethylene biguanide may be considered as potent alternatives to chlorhexidine-based preparations.

Phenotypic and genotypic analyses of clinical Fusobacterium nucleatum and Fusobacterium periodonticum isolates from the human gut

Fusobacterium nucleatum is a Gram-negative anaerobic rod that is part of the normal human microflora, and has also been associated with various infections. Bacterial strains belonging to the species are typically heterogeneous in both phenotype and genotype, which can hinder their identification in a clinical setting. The majority of F. nucleatum isolates originate from oral sites, however the species is also a resident of the human gastrointestinal tract. The aim of this study was to compare F. nucleatum isolates from human intestinal biopsy samples to try and determine whether isolates from this site are divergent from oral isolates. We used a variety of phenotypic and genotypic markers to compare 21 F. nucleatum and Fusobacterium periodonticum isolates from the GI tract to oral isolates and recognized type strains in order to study heterogeneity within this set. 16S rDNA and rpoB gene sequence analysis allowed us to build phylogenetic trees that consistently placed isolates into distinct clusters. 16S rDNA copy number analyses using Denaturing Gradient Gel Electrophoresis (DGGE) demonstrated potential for use as a method to examine clonality amongst species. Phenotypic analyses gave variable results that were generally unhelpful in distinguishing between phylogenetic clusters. Our results suggest that a) F. periodonticum isolates are not restricted to the oral niche; b) phenotypic classification is not sufficient to subspeciate isolates; c) heterogeneity within the species is extensive but constrained; and d) F. nucleatum isolates from the gut tend to identify with the animalis subspecies.

Fusobacterial infections: clinical spectrum and incidence of invasive disease

OBJECTIVES

Clinically significant infections caused by members of the genus Fusobacterium are rare. We sought to describe the spectrum of clinical disease and epidemiology of these conditions presenting to an acute hospital over a five year period.

METHODS

Clinical records relating to consecutive laboratory isolates of Fusobacterium species were reviewed and cases classified according to pre-specified definitions of primary site and invasive infection.

RESULTS

78 Fusobacterium isolates were identified, 25 of which were associated with invasive disease, most commonly in men (76% of cases). Invasive Fusobacterium necrophorum infection of the head and neck was not observed in patients over 50. Invasive intra-abdominal disease was not observed amongst those under 60. 2 cases of Fusobacterium nucleatum bacteraemia were identified in neutropenic children. One retroperitoneal abscess may have represented secondary infection due to periodontitis. Obstetric infections were the most common clinical syndromes associated with isolates from the female genital tract. The incidence of invasive head and neck disease in the population aged 15-50 was 6.7 per million/year. There were no deaths.

CONCLUSIONS

Invasive fusobacterial infections are rare, affect distinct patient groups and are associated with good clinical outcomes in the majority of cases.

Fusobacterium necrophorum middle ear infections in children and related complications: report of 25 cases and literature review

BACKGROUND

Fusobacterium necrophorum is associated with Lemierre syndrome (pharyngitis with septic thrombosis of the internal jugular veins) but it can also be involved in other head and neck infections, including sinusitis, parotitis, dental infections, and otitis media.

METHODS

This retrospective study analyzes a series of 25 pediatric cases of acute otitis media caused by F. necrophorum and treated in our institution between 1995 and 2006.

RESULTS

We observed 3 clinical presentations: (1) uncomplicated otitis media (44%; n = 11); (2) acute mastoiditis (40%; n = 10); and (3) otogenic variant of Lemierre syndrome (16%; n = 4) associating acute mastoiditis, suppurative thrombophlebitis of the lateral and/or cavernous sinuses, meningitis syndrome, and sometimes distant septic metastasis or extensive osteolysis of the temporal bone. Sixty percent of these cases were diagnosed during the last 4 years of the study. Children less than 1 year of age were at increased risk for Lemierre syndrome. Broad range 16S rDNA polymerase chain reaction and sequencing were used to confirm the identification of F. necrophroum and to detect secondary sites of infection. All patients had favorable clinical outcome, but complicated cases (mastoiditis and otogenic variant of Lemierre syndrome) required prolonged hospital stays and duration of treatment.

CONCLUSIONS

Based on bacteriologic investigation, we recommend systematic culture for anaerobes and that antibiotic treatment of F. necrophorum middle ear infections and subsequent complications includes coverage for anaerobic bacteria.

Prognostic factors and impact of antibiotherapy in 117 cases of anaerobic bacteraemia

Bacteraemia due to anaerobic bacteria occurs infrequently, making the systematic use of an anaerobic blood sample bottle in patients with sepsis controversial. We retrospectively reviewed the clinical and microbiological data from all cases of anaerobic bacteraemia in a teaching hospital over 2 years and determined the prognostic factors and antibiotic management. With the goal of evaluating the morbidity and mortality of bacteraemia due to anaerobic bacteria, a case-control study was also performed. One hundred eighty-four blood cultures from 125 patients grew at least one anaerobic bacterium, representing 0.5% of all and 7.0% of the positive blood cultures. One hundred seventeen patients were studied. In 24 cases, anaerobic blood cultures were associated with concomitant aerobic bacteria isolation. The most frequently isolated anaerobic species were Bacteroides sp. (n = 62), Clostridium sp. (n = 25), and Fusobacterium sp. (n = 12). The most frequent site of origin was the digestive tract (n = 61). In 51 cases, patients did not receive adequate empirical antianaerobic therapy. The mortality rate was 27%. Age [odds ratio (OR) 1.059; 95% confidence interval (CI) 1.021-1.100], cancer history (OR 3.21, 95% CI 1.126-9.156), and ineffective definitive antibiotherapy (OR 19.292, 95% CI 5.330-69.832) were independently associated with increased hospital mortality. The 72 patients that could be matched with patients without anaerobic bacteria according to their primary diagnosis had a longer hospitalisation and a trend toward increased mortality (P = 0.08). Anaerobic bacteraemia contributed significantly to the morbidity of the patients, and adequate empirical antibiotherapy may play an important role in the clinical outcomes.

Thyroid abscess due to a mixed anaerobic infection with Fusobacterium mortiferum

A rare case of a thyroid abscess due to mixed anaerobic flora containing Fusobacterium mortiferum in an immunocompetent patient is described. The patient was successfully treated with immediate surgical intervention and appropriate antimicrobial agents.

Clindamycin-resistant Fusobacterium varium bacteremia and decubitus ulcer infection

Bacteremia due to Fusobacterium spp. is unusual (<10% of cases of anaerobic bacteremia), and the isolation of Fusobacterium varium is especially uncommon. The most probable sources of Fusobacterium bacteremia are the respiratory, the gastrointestinal, and the genitourinary tracts. A.-M. Bourgault et al. (Clin. Infect. Dis. 25[Suppl. 2]:181-183) described 40 patients with Fusobacterium bacteremia; only 3 had Fusobacterium varium, and no one had decubitus scars as the portal of entry. In another published series (S. Henry, A. De Maria, and W. R. McCabe, Am. J. Med. 75:225-231, 1983) of 26 cases, two patients had concomitant pulmonary lesions and decubitus ulcers but there was no identification to the species level mentioned. We report a case of Fusobacterium varium bacteremia and infected sacral decubitus ulcer in an elderly patient.

Fusobacterium necrophorum infections in animals: Pathogenesis and pathogenic mechanisms

Fusobacterium necrophorum, a Gram-negative, non-spore-forming anaerobe, is a normal inhabitant of the alimentary tract of animals and humans. Two subspecies of F. necrophorum, subsp. necrophorum (biotype A) and subsp. funduliforme (biotype B), have been recognized, that differ morphologically, biochemically, and biologically. The subsp. necrophorum is more virulent and is isolated more frequently from infections than the subsp. funduliforme. The organism is an opportunistic pathogen that causes numerous necrotic conditions (necrobacillosis), either specific or non-specific infections, in a variety of animals. Of these, bovine liver abscesses and foot rot are of significant concern to the cattle industry. Liver abscesses arise with the organisms that inhabit the rumen gaining entry into the portal circulation, and are often secondary to ruminal acidosis and rumenitis complex in grain-fed cattle. Foot rot is the major cause of lameness in dairy and beef cattle. The pathogenic mechanism of F. necrophorum is complex and not well defined. Several toxins or secreted products, such as leukotoxin, endotoxin, hemolysin, hemagglutinin, proteases, and adhesin, etc., have been implicated as virulence factors. The major virulence factor appears to be leukotoxin, a secreted protein of high molecular weight, active specifically against leukocytes from ruminants. The complete nucleotide sequence of the leukotoxin operon of F. necrophorum has been determined. The operon consists of three genes (lktBAC) of which the second gene (lktA) is the leukotoxin structural gene. The leukotoxin appears to be a novel protein and does not share sequence similarity with any other leukotoxin. F. necrophorum is also a human pathogen and the human strains appear to be different from the strains involved in animal infections.

Lemierre's syndrome: case report in a pediatric patient

Lemierre's syndrome was described in 1936 as a severe oropharyngeal infection followed by septic thrombophlebitis of the internal jugular vein and disseminated metastatic infections. Cases occur typically in previously healthy young adults and children. Fusobacterium necrophorum is the main anaerobic bacterium implicated. We present a septic 2-month-old infant with mastoiditis, multiple sites of osteoarthritis and multiple subcutaneous abscesses. No underlying anatomic or immunologic abnormalities were identified. Fusobacterium necrophorum was recovered from blood and bone samples obtained intraoperatively. Treatment included anaerobic coverage and drainage of septic foci. The patient was discharged home on 35th hospital day with oral amoxicillin-clavulanic acid and he recovered without sequelae. This was the first case of Lemierre's syndrome in our hospital. We want to highlight the absence of jugular vein thrombophlebitis, the presence of mastoiditis as previous infection and the surprising appearance of this infection in an edentulous 2-month-old infant.

Human necrobacillosis, with emphasis on Lemierre's syndrome

Lemierre's syndrome is the classical presentation of human necrobacillosis. It is characterized by a primary infection in the head in a young, previously healthy person who subsequently develops persistent high fever and disseminated metastatic abscesses, frequently including a septic thrombophlebitis of the internal jugular vein. The main pathogen is Fusobacterium necrophorum, an obligate anaerobic, pleomorphic, gram-negative rod. Clinical microbiologists have a key role in alerting clinicians and advising proper antibiotic treatment when the characteristic microscopic morphology of the pleomorphic F. necrophorum is seen in Gram stains from positive anaerobic cultures of blood and pus. Early diagnosis and prolonged appropriate antibiotic treatment with good anaerobic coverage are crucial to reduce morbidity and mortality. F. necrophorum also causes human necrobacillosis with foci caudal to the head, mainly in elderly patients with high mortality related to age and predisposing diseases, such as cancers of the primary focus.

Development of oral bacterial flora in young children

The intimate relationship with bacteria is a fundamental factor in the health status of an individual. After birth infants are exposed to continuous person-to-person and environmental contacts with microbes, and the development of the indigenous microflora begins on the surfaces of the human body. In a developing ecosystem microbial colonization may easily occur because of the still inadequate host response. Adhesion is the initial event in the colonization of bacteria. In the mouth, only mucosal surfaces are available during the first months of life. After teeth emerge, the number of attachment sites and potential niches increases significantly. Bacteria adhere not only to oral surfaces but also to each other, forming multigeneric communities where specific partner relationships influence their composition and stability. Viridans streptococci and a strictly anaerobic species, Fusobacterium nucleatum, are of interest in this context. The oral colonization pattern differs between individuals already in infancy; variable bacterial load in saliva of attendants and other close contacts and the frequency of this bacterial exposure may partly account for individual differences. In addition, the exposure of an infant to antibiotics affects the quality of colonizing bacteria. This article presents an overview of the age-related acquisition of oral bacteria and the role of the indigenous oral microflora in health and disease.

Oral colonization by anaerobic bacteria during childhood: role in health and disease

Anaerobes constitute a significant part of bacterial communities in human mouths. Their ability to colonize and survive in the environment, where remarkable changes occur during early childhood, is fundamental for oral homeostasis. However, relatively little is known of the time of colonization and succession of anaerobic species in the oral cavity. This article presents an up-to-date review on the development of the oral anaerobic microflora in respect to age, and in addition, considers some aspects of the role of oral anaerobes in health and disease.