Low usefulness of reporting tonsillar PCR Ct-values in pharyngeal infections with Fusobacterium necrophorum

Tonsillar Fusobacterium necrophorum PCR Ct-values were higher in participants with asymptomatic tonsillar carriage than patients with pharyngeal infections. However, Ct-values were not associated with severity of disease or predictive of development of complications and hence lacked clinical usefulness. The reporting of F. necrophorum Ct-values in clinical samples is not recommended.

Nasopharyngeal Isolates from a Cohort of Medical Students with or without Pharyngitis

Objectives

Few studies have investigated pharyngeal colonisation in the United Arab Emirates (UAE). This study aims to identify the pharyngeal organisms present in a cohort of medical students with and without symptomatic pharyngitis.

Methods

This study was conducted between September 2016 and June 2018 at the College of Medicine and Health Sciences, UAE University, Al-Ain. Nasopharyngeal swabs were collected from preclinical and clinical medical students attending the college during the study period. The specimens were tested for 16 viral and nine bacterial pathogens using a real-time polymerase chain reaction assay.

Results

A total of 352 nasopharyngeal swabs were collected from 287 students; of these, 22 (7.7%) had pharyngitis symptoms. Overall, the most common isolates were human rhinovirus, Streptococcus pneumoniae and Haemophilus influenzae, with no significant differences in terms of gender, year of study or stage of study. The prevalence of S. pyogenes in asymptomatic and symptomatic students was 1.1% and 0%, respectively. A Centor score of ≥2 was not associated with S. pyogenes-positive samples. Six pathogens were isolated from symptomatic students including H. influenzae. Fusobacterium necrophorum was not detected in any of the samples.

Conclusion

The diagnosis and management of pharyngitis should be tailored to common pathogens in the region. This study found that S. pyogenes and F. necrophorum were not detected among students with symptoms of pharyngitis; moreover, Centor scores of ≥2 were not associated with the presence of S. pyogenes. This cut-off score therefore should not be employed as an empirical measure to initiate penicillin therapy in this population.

[A sepsis that you don't expect… Lemierre's syndrome. Description of a clinical case.]

A healthy 16-year-old boy was hospitalized for fever, septic condition and thrombosis of the left internal jugular vein: The diagnosis of Lemierre syndrome (LS) with positive blood culture for Fusobacterium necrophorum was formalized. He was treated with antibiotics and anticoagulant therapy with enoxaparin with complete recovery. Four weeks after discharge, the jugular vein ecodoppler showed complete resolution of the thrombosis. LS is characterized by thrombosis of the internal jugular vein and anaerobic bacteremia often caused by Fusobacterium necrophorum. It is a rare disease in the post-antibiotic era, but with an increase in cases over the last twenty years. LS should be suspected in young, healthy patients with persistent pharyngitis followed by sepsis, pneumonia or atypical laterocervical pain. The diagnosis is confirmed by the identification of jugular venous thrombosis and is further confirmed by the growth of anaerobic bacteria on blood culture. Prolonged antibiotic and anticoagulant therapies are the essential elements of treatment. However, anticoagulant therapy for internal venous thrombosis associated with LS remains a controversy.

Bacteriology of peritonsillar abscess: the changing trend and predisposing factors

Introduction

Peritonsillar abscess is the most common deep neck infection. The infectious microorganism may be different according to clinical factors.

Objective

To identify the major causative pathogen of peritonsillar abscess and investigate the relationship between the causative pathogen, host clinical factors, and hospitalization duration.

Methods

This retrospective study included 415 hospitalized patients diagnosed with peritonsillar abscess who were admitted to a tertiary medical center from June 1990 to June 2013. We collected data by chart review and analyzed variables such as demographic characteristics, underlying systemic disease, smoking, alcoholism, betel nut chewing, bacteriology, and hospitalization duration.

Results

A total of 168 patients had positive results for pathogen isolation. Streptococcus viridans (28.57%) and Klebsiella pneumoniae (23.21%) were the most common microorganisms identified through pus culturing. The isolation rate of anaerobes increased to 49.35% in the recent 6 years (p = 0.048). Common anaerobes were Prevotella and Fusobacterium spp. The identification of K. pneumoniae increased among elderly patients (age > 65 years) with an odds ratio (OR) of 2.76 (p = 0.03), and decreased in the hot season (mean temperature > 26 °C) (OR = 0.49, p = 0.04). No specific microorganism was associated with prolonged hospital stay.

Conclusion

The most common pathogen identified through pus culturing was S. viridans, followed by K. pneumoniae. The identification of anaerobes was shown to increase in recent years. The antibiotics initially selected should be effective against both aerobes and anaerobes. Bacterial identification may be associated with host clinical factors and environmental factors.

[Not Available]

The purpose of this case report and discussion is to heighten the awareness of Lemierres syndrome (postanginal sepsis).  Affected patients present in various fields of medicine and an increased incidence of "the forgotten disease" may be expected. Fusobacterium necrophorum is the most common pathogen. The clinical course includes a primary head or neck infection with thrombosis of the internal jugular vein with subsequent septic pulmonary embolization. The syndrome bears considerable morbidity and even mortality. People aged 15-25 years are commonly affected. Early diagnosis through positive blood culture and confirmation of jugular vein thrombosis combined with prompt antibiotic treatment and source control is mandatory in the management of Lemierre's syndrome. Assessment of vital organ function is recommended across the continuum of care as this facilitates recognition and initiation of therapeutic measures to counteract a complicated clinical course.

Lesson of the month 1: Lemierre's syndrome: a reminder of the 'forgotten disease'

Lemierre's syndrome is a condition characterised by suppurative thrombophlebitis of the internal jugular (IJ) vein following a recent oropharyngeal infection, with resulting septicaemia and metastatic lesions. It is strongly associated with Fusobacterium necrophorum, a Gram-negative bacilli. Key to early diagnosis is awareness of the classical history and course of this illness, and therefore to ask about a history of recent oropharyngeal infections when a young patient presents with fever and rigors. Diagnosis can be confirmed by showing thrombophlebitis of the IJ vein, culturing F necrophorum from normally sterile sites or demonstrating metastatic lesions in this clinical setting. The cornerstone of management is draining of purulent collection where possible and prolonged courses of appropriate antibiotics. In this article, we review a case study of a young man with Lemierre's syndrome and discuss the condition in more detail.

Peritonsillar abscess: clinical aspects of microbiology, risk factors, and the association with parapharyngeal abscess

PTA is a collection of pus located between the tonsillar capsule and the pharyngeal constrictor muscle. It is considered a complication of acute tonsillitis and is the most prevalent deep neck infection (approximately 2000 cases annually in Denmark) and cause of acute admission to Danish ENT departments. Teenagers and young adults are most commonly affected and males may predominate over females. However, no studies of age- and gender-stratified incidence rates have previously been published. Furthermore, smoking may be associated with increased risk of peritonsillar abscess (PTA) development, although the magnitude of the association has not been estimated. Complications are relatively rare. They include parapharyngeal abscess (PPA), upper airway obstruction, Lemierre´s syndrome, necrotizing fasciitis, mediastinitis, erosion of the internal carotid artery, brain abscess, and streptococcal toxic shock syndrome. The treatment consists of abscess drainage and antimicrobial therapy. There are three accepted methods of surgical intervension: needle aspiration, incision and drainage (ID), and acute tonsillectomy (á chaud). Internationally, there is a strong trend towards less invasive surgical approach to PTA treatment with avoidance of acute tonsillectomy, needle aspiration instead of ID, and in some cases even antibiotic treatment without surgical drainage. The preferred antibiotic regimen varies greatly between countries and centers. Group A streptococcus (GAS) is the only established pathogen in PTA. However, GAS is only recovered from approximately 20% of PTA patients. The pathogens in the remaining 80% are unknown. Culturing of PTA pus aspirates often yields a polymicrobial mixture of aerobes and anaerobes. As the tonsils of healthy individuals are already heavily and diversely colonized, the identification of significant pathogens is challenging. In addition, when studying PTA microbiology, one must consider diagnostic precision, collection, handling, and transportation of appropriate specimens, choice of methodology for detection and quantification of microorganisms, current or recent antibiotic treatment of patients, potential shift in significant pathogens during the course of infection, and factors associated with increased risk of PTA development.  The trend towards de-escalated surgical intervention and increasing reliance on antibiotic treatment, require studies defining the significant pathogens in PTA in order to determine optimal antibiotic regimens. Complications secondary to PTA may be avoided or better controlled with improved knowledge concerning the significant pathogens in PTA. Furthermore, identification of pathogens other than GAS, may lead the way for earlier bacterial diagnosis and timely intervention before abscess formation in sore throat patients. The identification and quantification of risk factors for PTA development constitutes another approach to reduce the incidence of PTA. As clinicians, we noticed that FN was recovered from PTA patients with increasing frequency and that patients infected with Fusobacterium necrophorum (FN) seemed to be more severely affected than patients infected with other bacteria. Furthermore, we occationally observed concomitant PPA in addition to a PTA, which made us hypothesize that PPA and PTA is often closely related and may share significant pathogens. Hence, our aims were: 1. To explore the microbiology of PTA with a special attention to Fusobacterium necrophorum (FN). 2. To elucidate whether smoking, age, gender, and seasons are risk factors for the development of PTA. 3. To characterize patients with PPA, explore the relationship between PPA and PTA, identify the pathogens associated with PPA, and review our management of PPA. In a retrospective study on all 847 PTA patients admitted to the ENT department at Aarhus University Hospital (AUH) from 2001 to 2006, we found that FN was the most prevalent (23%) bacterial strain in pus specimens. FN-positive patients displayed significantly higher infection markers (CRP and neutrophil counts) than patients infected with other bacteria (P = 0.01 and P < 0.001, respectively). In a subsequent prospective and comparative study on 36 PTA patients and 80 patients undergoing elective tonsillectomy (controls), we recovered FN from 58% of PTA aspirates. Furthermore, FN was detected significantly more frequently in the tonsillar cores of PTA patients (56%) compared to the tonsillar cores of the controls (24%) (P = 0.001). We also analysed sera taken acutely and at least two weeks after surgery for the presence of anti-FN antibodies. We found increasing levels (at least two-fold) of anti-FN antibodies in eight of 11 FN-positive (in the tonsillar cultures) PTA patients, which was significantly more frequent compared to none of four FN-negative PTA patients and nine of 47 electively tonsillectomized controls (P = 0.026 and P < 0.001, respectively). Blood cultures obtained during acute tonsillectomy mirrored the bacterial findings in the tonsillar specimens with 22% of patients having bacteremia with FN. However, bacteremia during elective tonsillectomy was at least as prevalent as bacteremia during quinsy tonsillectomy, which challenges the distinction made by the European Society of Cardiology between quinsy and elective tonsillectomy, namely that antibiotic prophylaxis is only recommended to patients undergoing procedures to treat an established infection (i.e. PTA). Using PCR analysis for the presence of herpes simplex 1 and 2, adenovirus, influenza A and B, Epstein-Barr virus (EBV), and respiratory syncytial virus A and B, we explored a possible role of viruses in PTA. However, our results did not indicate that any of these viruses are involved in the development of PTA. Privious studies have documented an association between EBV and PTA in approximately 4% of PTA cases. In addition to the involvement of GAS, the following findings suggest a pathogenic role for FN in PTA: 1. Repeated high isolation rates of FN in PTA pus aspirates. 2. Higher isolation rates in PTA patients compared to electively tonsillectomised controls. 3. Development of anti-FN antibodies in FN-positive patients with PTA. 4. Significantly higher inflammatory markers in FN-positive patients compared to PTA patients infected with other bacteria. We studied the smoking habits among the same 847 PTA patients admitted to the ENT department, AUH from 2001 to 2006. We found that smoking was associated with increased risk of PTA for both genders and across all age groups. The increased risk of PTA among smokers was not related to specific bacteria. Conclusions on causality cannot be drawn from this retrospective study, but the pathophysiology behind the increased risk of PTA in smokers may be related to, previously shown, alterations in the tonsillar, bacterial flora or the local and systemical inflammatory and immunological milieu. Studying all 1,620 patients with PTA in Aarhus County from 2001 to 2006 and using population data for Aarhus County for the same six years, age- and gender-stratified mean annual incidence rates of PTA were calculated. The incidence of PTA was highly related to age and gender. The seasonal variation of PTA was insignificant. However, the microbiology of PTA fluctuated with seasons: GAS-positive PTA cases were significantly more prevalent in the winter and spring compared to the summer, while FN-positive PTA patients exhibited a more even distribution over the year, but with a trend towards higher prevalence in the summer than in the winter. In a series of 63 patients with PPA, we found that 33 (52%) patients had concomitant PTA. This association between PPA and PTA was much higher than previously documented. We therefore suggest that combined tonsillectomy and intrapharyngeal incision in cases where PTA is present or suspected. The results of our routine cultures could not support a frequent role of FN in PPA. Based on our findings suggesting that FN is a frequent pathogen in PTA, we recommend clindamycin instead of a macrolide in penicillin-allergic patients with PTA. Furthermore, cultures made from PTA aspirates should include a selective FN-agar plate in order to identify growth of this bacterium. Recent studies of sore throat patients document an association between recovery of FN and acute tonsillitis. Studying the bacterial flora of both tonsils in study II, we found almost perfect concordance between the bacterial findings of the tonsillar core at the side of the abscess and contralaterally. This finding suggests that FN is not a subsequent overgrowth phenomenon after abscess development, but that FN can act as pathogen in severe acute tonsillitis. Future studies of patients with FN-positive acute tonsillitis focusing on the optimal methods (clinical characteristics, culture, polymerase chain reaction, or other) for diagnosis and whether antibiotics (and which) can reduce symptoms and avoid complications are warranted. Until further studies are undertaken, we recommend clinicians to have increased focus on acute tonsillitis patients aged 15-24 years with regards to symptoms and findings suggestive of incipient peritonsillar involvement. We have conducted a number of studies with novel findings: 1. FN is a significant and prevalent pathogen in PTA. 2. Bacteremia during abscess tonsillectomy is no more prevalent than during elective tonsillectomy. 3. The development of anti-FN antibodies in FN-positive PTA patients. We have used novel approaches as principles to suggest pathogenic significance of candidate microorganisms: 1. Comparative microbiology between PTA patients and "normal tonsils". 2. Measurements indicating larger inflammatory response compared to clinically equivalent infection.

Prevalence of Fusobacterium necrophorum and other upper respiratory tract pathogens isolated from throat swabs

Fusobacterium necrophorum, an anaerobic, Gram-negative rod, has been identified recently as a significant cause of persistent sore throat syndrome (PSTS). This disease is characterised by chronic, recurrent or persistent sore throat, which is believed to respond poorly to penicillin in vivo. The aim of this study is to examine the prevalence of F. necrophorum in all throat swabs received in our diagnostic microbiology department and to compare the results with those for other recognised respiratory pathogens. All throat swabs received in the laboratory over a four-week period were cultured for beta-haemolytic streptococcus groups A, C and G, Corynebacterium diphtheriae, Arcanobacterium haemolyticum and F. necrophorum. Latex agglutination techniques, phenotypic reactions and antibiograms are used to identify these organisms. The age of the patient and the clinical details as stated on the request form were noted. Among a total of 248 samples, 27 were positive for beta-haemolytic streptococcus group A, two were positive for beta-haemolytic streptococcus group C, five were positive for beta-haemolytic streptococcus group G and 24 were positive for F. necrophorum. The most common isolate in the under 20 age group was beta-haemolytic streptococcus group A. In the over 20 age group, F. necrophorum was the pathogen most frequently isolated. A clinical diagnosis of 'sore throat' was most likely to be positive for beta-haemolytic streptococcus group A, a clinical diagnosis of PSTS was most likely to be positive for F. necrophorum and a clinical diagnosis of 'tonsillitis' was equally likely to be caused by beta-haemolytic streptococcus group A or F. necrophorum. beta-haemolytic streptococcus group A was present in 11% of the samples and F. necrophorum was present in 10% of the samples. In total, these two pathogens accounted for 18.5% of throat infections in the sampled group. The results show that F. necrophorum is as significant a cause of throat infection as is beta-haemolytic streptococcus group A. Examination of this provisional data suggests that targeting culture towards these two pathogens may be possible in certain cohorts of patients if more precise clinical data are received from medical staff. However, based on the clinical symptoms routinely provided by clinicians requesting microscopy, culture and sensitivity on throat swabs, F. necrophorum culture is required on all throat swabs received in the laboratory.

[Loco-regional complications of pharyngitis: the example of Lemierre's syndrome]

Pharyngitis is a common cause of consultation in ambulatory medicine. Although it is benign in most cases, serious complications may happen and must be recognized quickly. Lemierre's syndrome is one of them. It consists in the association of thrombosis of the internal jugular vein and septic emboli that generally involve the lungs and is classically associated with Fusobacterium necrophorum. It is usually found in young and healthy adults and has an estimated mortality of 5%. Diagnosis relies essentially on the characteristic presentation of the disease. Therapy consists of surgical drainage of purulent collections and necrotic tissues associated with a prolonged course of antibiotics. Some authors also recommend a anticoagulation.

Importance of blood cultures to aid the diagnosis of Lemierre's syndrome

This is a case report of Lemierre's syndrome, a septic thrombophlebitis of the internal jugular vein (IJV) usually preceded by pharyngitis and bacteraemia with an anaerobic organism. Fusobacterium necrophorum is ananaerobic Gram-negative bacillus and is the most common organism reported to cause Lemierre's syndrome which usually occurs one to three weeks post pharyngitis or oropharyngeal surgery. A 21-year-old patient presented with signs of sepsis and a history of sore throat, fever, and tender cervical lymph nodes. Blood cultures grew F. necrophorum and Computed Tomography (CT) showed a filling defect in the left retromandibular vein and thrombosis in the left internal jugular vein (IJV) consistent with Lemierre's syndrome. This is an uncommon condition which normally occurs in young individuals and diagnosis is often delayed.

Study: bacterium associated with rare "forgotten" disease also responsible for more sore throats than Group A strep in young adults

New findings show that Fusobacterium necrophorum, the bacterium responsible for most cases of Lemierre's disease, a relatively rare condition that is sometimes called "the forgotten disease," is also the culprit for more sore throats than Group A strep bacterium among college-aged patients. However, as there is no point-of-care test for F. necrophorum, providers need to rely on physical examination when determining whether a sore throat is due to the bacterial infection. In an analysis of 312 college students, investigators detected F. necrophorum in more than 20% of patients with symptoms of sore throat. Group A strep was only detected in 10% of the cases, and Group C or G strep was detected in 9% of the cases. Researchers note that the F. necrophorum bacterium is associated with both Lemierre's disease and most cases involving a peritonsillar abscess, a deep infection of the head or neck that occurs most commonly in young adults. Infections caused by F. necrophorum can be effectively treated with penicillin or a cephalosporin, but do not typically respond to azithromycin.

Lemierre's Syndrome Associated with Periodontal Injury-derived Odontogenic Infection that Did Not Respond to Meropenem

A 33-year-old previously healthy man injured his gums and subsequently developed dyspnea and fever. A chest X-ray showed nodules and infiltrates in both lungs, and the patient was initially diagnosed with pneumonia and administered meropenem hydrate, although his symptoms did not improve. A blood culture identified Fusobacterium necrophorum, and thrombophlebitis in the internal jugular vein of the neck was observed on computed tomography and ultrasound scans. We replaced the meropenem with clindamycin, sulbactam/ampicillin and metronidazole, and the patient's symptoms improved.

[Life-threatening appendicitis caused by Fusobacterium necrophorum]

Fusobacterium necrophorum is a well-known cause of Lemierre's syndrome. Recent studies suggest a causative association between F. necrophorum and acute appendicitis. We present a case of a 15-year-old previously healthy girl who presented with acute non-perforated appendicitis, intra-abdominal abscesses and thrombosis that led to omental necrosis. This resulted in a life-threatening septic shock with the need for prolonged intensive care. We suggest that F. necrophorum identified in pus from the abdomen caused this fulminant variation of appendicitis with findings similar to those seen with Lemierre's syndrome.

Fusobacterium necrophorum in a pediatric retropharyngeal abscess: A case report and review of the literature

We present the case of a 17-year-old boy who developed a deep space neck infection following cervical trauma. He was initially managed conservatively with broad-spectrum antibiotics, but when he failed to improve clinically, he required surgical drainage. Wound cultures grew Fusobacterium necrophorum, an uncommon pathogen that can cause pediatric deep neck space infections, especially when it is not associated with Lemierre syndrome. The prognosis for this infection is favorable when it is identified early. Treatment with culture-directed antibiotics and surgical drainage as indicated is appropriate. When treating a pediatric deep neck space infection empirically, physicians should avoid treatment with a macrolide antibiotic, since Fusobacterium spp may be involved and they are often resistant to this class of drugs.

A longitudinal study of the role of Dichelobacter nodosus and Fusobacterium necrophorum load in initiation and severity of footrot in sheep

Footrot is an infectious bacterial disease of sheep that causes lameness. The causal agent is Dichelobacter nodosus. There is debate regarding the role of Fusobacterium necrophorum in disease initiation. This research used an observational longitudinal study of footrot, together with quantitative PCR (qPCR) of bacterial load of D. nodosus and F. necrophorum, to elucidate the roles of each species in the development of disease. All feet of 18 a priori selected sheep were monitored for five weeks assessing disease severity (healthy, interdigital dermatitis (ID) and severe footrot (SFR)) and bacterial load. A multinomial model was used to analyse these data.

Key unadjusted results were that D. nodosus was detected more frequently on feet with ID, whereas F. necrophorum was detected more frequently on feet with SFR. In the multinomial model, ID was associated with increasing log₁₀ load of D. nodosus the week of observation (OR = 1.28 (95% CI = 1.08–1.53)) and the week prior to development of ID (OR = 1.20 (95% CI = 1.01–1.42). There was no association between log₁₀ load² of F. necrophorum and presence of ID (OR = 0.99 (95% CI = 0.96–1.02))). SFR was associated with increasing log₁₀ load of D. nodosus the week before disease onset (OR = 1.42 (95% CI = 1.02–1.96)) but not once SFR had occurred. SFR was positively associated with log₁₀ load² of F. necrophorum once disease was present (OR = 1.06 (95% CI = 1.01–1.11)). In summary, there was an increased risk of increasing D. nodosus load the week prior to development of ID and SFR and during an episode of ID. In contrast, F. necrophorum load was not associated with ID before or during an episode, and was only associated with SFR once present. These results contribute to our understanding of the epidemiology of footrot and highlight that D. nodosus load plays the primary role in disease initiation and progression, with F. necrophorum load playing a secondary role. Further studies in more flocks and climates would be useful to confirm these findings. This study identifies that D. nodosus load is highest during ID. This supports previous epidemiological findings, which demonstrate that controlling ID is the most effective management strategy to prevent new cases of ID and SFR.

Fusobacterium necrophorum, and not Dichelobacter nodosus, is associated with equine hoof thrush

The aim of this study was to determine which of the two species, Fusobacterium necrophorum or Dichelobacter nodosus, are associated with hoof thrush in horses. Fourteen hoof samples, collected from eight horses with thrush and 14 samples collected from eight horses with healthy hooves, were examined for the presence of F. necrophorum, Fusobacterium equinum and D. nodosus. Only isolates with phenotypic characteristics representing Fusobacterium could be cultured. Total DNA extracted from the 28 hoof samples was amplified by using DNA primers designed from gene lktA, present in F. necrophorum subsp. necrophorum, F. necrophorum subsp. funduliforme and F. equinum, and gene fimA, present in D. nodosus. The lktA gene was amplified from five of the 14 infected hoof samples and from one hoof sample without thrush. The DNA sequence of the amplified ltkA gene was identical to the lktA gene of the type strain of F. necrophorum (GenBank accession number AF312861). The isolates were phenotypically differentiated from F. equinum. No DNA was amplified using the fimA primer set, suggesting that F. necrophorum, and not D. nodosus, is associated with equine hoof thrush. Hoof thrush in horses is thus caused by F. necrophorum in the absence D. nodosus. This is different from footrot in sheep, goats, cattle and pigs, which is caused by the synergistic action of F. necrophorum and D. nodosus.

Early diagnosis of Lemierre's syndrome based on a medical history and physical findings

A 37-year-old woman presented with fever and rigor after experiencing respiratory symptoms the previous week that had resolved within a few days. On presentation, her neck was swollen along the right sternocleidomastoid muscle, and chest CT showed pulmonary septic embolisms. Lemierre's syndrome was strongly suspected based on the patient's medical history and physical findings. Further examination revealed venous thrombus, and Fusobacterium necrophorum was later isolated from blood cultures. Antibiotics for anaerobes were administered before a final diagnosis was made, and the patient's symptoms thereafter improved. A rapid diagnosis is essential, since Lemierre's syndrome can be fatal with a diagnostic delay.

First case of Fusobacterium necrophorum endocarditis to have presented after the 2nd decade of life

Fusobacterium necrophorum, an obligate, anaerobic, filamentous, gram-negative rod, is thought to be a normal inhabitant of the mucous membranes in human beings. Fusobacterium species have been implicated in cases of Lemierre syndrome and other pathologic conditions. Their reported association with infective endocarditis is extremely rare. We describe the case of a previously healthy 34-year-old man who emergently presented with flu-like symptoms and dyspnea on exertion. He had recently undergone a dental procedure. Empiric antibiotic therapy was initiated. Blood cultures were positive for metronidazole-resistant F. necrophorum. A transesophageal echocardiogram revealed 2 mobile vegetations on the mitral valve. Despite the antibiotic therapy, the patient's respiratory status worsened and, after 3 weeks, he died. On the basis of the organism's pathophysiology and the patient's recent dental procedure, the oral cavity was the likely source of the bacteremia. Our patient's case underscores the importance of recognizing Fusobacterium bacteremia as a possible cause of endocarditis. To our knowledge, this is the first reported case of monomicrobial F. necrophorum endocarditis to have presented in a patient after the 2nd decade of life. In addition, it is apparently only the 4th report of F. necrophorum mitral valve endocarditis with case results derived from modern culture techniques.

Lemierre's syndrome: a sinister sore throat every clinician should remember

Fusobacterium necrophorum is an anaerobic gram-negative bacterium that can present as a painful sore throat. Although uncommon, clinicians need to be aware of this condition as this can present a diagnostic challenge, with the initial symptoms being non-specific followed by a fulminant course. We present the case of a previously healthy girl who presented with a sore throat but later developed a full-fledged picture of Lemierre's disease. She developed bilateral pleural effusion and internal jugular venous thrombosis and needed intensive care management, a prolonged course of intravenous antibiotics and anticoagulation therapy.

[Lemierre's syndrome following peritonsillar abscess]

Lemierre's syndrome is a rare but serious condition, characterized by disseminated infection with Fusobacterium necrophorum, most often originating from the oropharynx. Thrombophlebitis of the internal jugular vein and septic embolisms to various organs is the typical clinical picture. We describe a 16-year-old man with peritonsillar abscess who developed abscesses in lungs, liver and spleen. The patient was admitted to the ICU and treated with surgical drainage of infectious foci, antibiotics and anticoagulant therapy. After six weeks of antibiotic treatment the patient was discharged with no sequelae.

[Treatment of peritonsillar abscess]

Peritonsillar abscess (PTA) is associated with high morbidity and can cause serious and life-threatening complications. In Denmark, the most commonly isolated bacteria are Fusobacterium necrophorum and Streptococcus pyogenes gr. A. The incidence of PTA in Denmark is 41/100,000/year, the highest incidence ever reported for PTA. There is no definite consensus on the treatment. We recommend most patients treated with puncture and antibiotics as outpatients, and if necessary acute tonsillectomy instead of interval tonsillectomy. Steroids may be of value.

Caudal vena caval thrombosis following treatment of deep digital sepsis

A diagnosis of caudal vena caval thrombosis was made by ultrasonography of a Holstein cow presented for lethargy and poor milk production. Medical treatment was unsuccessful and the cow was euthanized. The diagnosis was confirmed at necropsy and Fusobacterium necrophorum was isolated from the thrombus. This paper discusses potential novel sources of caval thrombosis in this case.

[Brain abscess due to Fusobacterium necrophorum in a patient with convulsion and no signs of meningitis]

Here, we report brain abscess due to Fusobacterium necrophorum (F. necrophorum) in a 78-year-old healthy man. He developed convulsion and did not have any signs of meningitis. Although the brain magnetic resonance imaging findings of the left occipital lobe were typical of a brain abscess, his cerebrospinal fluid examination revealed only slight pleocytosis and mild increase in protein levels. Thus, it was difficult to rule out the possibility of metastatic brain tumor; the patient's condition was provisionally diagnosed as symptomatic epilepsy secondary to brain abscess. His convulsion disappeared soon after administration of antiepileptic, antibacterial, and steroid agents. A craniotomy was performed to evacuate the abscess, and F. necrophorum was identified by culturing the abscess contents. After the operation, he was treated with appropriate antibacterial agents, which resulted in resolution of the brain abscess. Although Fusobacterium species are gram-negative anaerobic bacilli commensal of the human oropharynx, we need to recognize that Fusobacterium species can be a primary pathogen causing brain abscesses and may leave residual neurological sequelae without early appropriate treatment.

A case of Lemierre's syndrome in association with liver abscess without any other metastatic lesions

Lemierre's syndrome (LS) is characterized by pharyngitis followed by septicemia, internal jugular vein thrombophlebitis, and metastatic embolization in general. LS is commonly caused by Fusobacterium necrophorum. Herein, we present a case of LS with liver abscesses that presented as a sole metastatic lesion. We were not able to diagnose LS until Fusobacterium necrophorum was isolated due to the lack of the common involvement. Doripenem was effective against the pathologic features including the liver abscesses. LS should be taken into consideration when clinicians find liver abscesses following pharyngitis even when the common complications of LS are not detected.

[Pneumonia caused by Fusobacterium necrophorum: is Lemierre syndrome still current?]

Fusobacterium necrophorum is a non-spore-forming gram-negative anaerobic bacillus that may be the causative agent of localized or severe systemic infections. Systemic infections due to F.necrophorum are known as Lemierre's syndrome, postanginal sepsis or necrobacillosis. The most common clinical course of severe infections in humans is a progressive illness from tonsillitis to septicemia in previously healthy young adults. A septic thrombophlebitis arising from the tonsillar veins and extending into the internal jugular vein leads to septicemia and septic emboli contributing to the development of necrotic abscesses especially in lungs and other tissues such as liver, bone and joints. In this case report, a previously healthy man with pneumonia and empyema due to F.necrophorum has been presented. A 22 year-old man suffering from sore throat for seven days was admitted to emergency department with ongoing fever and dysphagia for three days. On admission he was already taking amoxicillin-clavulanic acid and his complaints were relieved with continuation of therapy to a total of 10 days. However, five days after the cessation of treatment he developed productive cough, fever and generalized myalgia. On physical examination, there were crackles on right lower lung, and chest X-ray revealed pulmonary consolidation on the right middle lobe. Levofloxacin therapy was started based on the diagnosis of pneumonia. While polymorphonuclear leucocytes and intracellular gram-negative bacilli were seen in Gram stained sputum smear, sputum culture was reported as normal flora. Although the patient's status had started to improve with treatment, his condition deteriorated with development of fever and dyspnea. Chest X-ray revealed consolidation, pulmonary infiltrates, pleural effusion and air-fluid level on the right. Meropenem, clarithromycin and linezolid were initiated and a chest tube was inserted with the preliminary diagnosis of necrotizing pneumonia, empyema and type-1 respiratory failure. While there was no growth on bronchoalveolar lavage fluid culture, thoracentesis material inoculated into thioglycolate broth revealed turbidity. Further inoculation onto Schaedler agar which was incubated under anaerobic conditions, yielded growth of catalase negative, indol positive, gram-negative anaerobic bacilli identified as F.necrophorum by BBL Crystal system (Becton Dickinson, USA). The detailed history of the patient revealed that fish bone had stuck in his throat a week ago. Clarithromycin and linezolid were discontinued and he was recovered within six weeks of meropenem treatment. F.necrophorum infection should be considered in the differential diagnosis of persistent head and neck infections with rapidly progressive metastatic necrotic lesions especially in healthy young adults and clindamycin or metranidazol should be added to the treatment protocols.

Similar recovery rates of Fusobacterium necrophorum from recurrently infected and non-infected tonsils

INTRODUCTION

Recent studies implicate the presence of Fusobacterium necrophorum (FN) in recurrent tonsillitis (RT), acute tonsillitis and peritonsillar abscess. The objective of the present study was to determine whether FN plays a role in RT by comparing bacteriologic results from patients suffering from RT, tonsillar hypertrophy and halitosis or persistent sore throat syndrome (PSTS). We analyzed both tonsils to determine the degree of concordance.

MATERIAL AND METHODS

A prospective study was conducted in 80 patients aged 8-30 years who were undergoing elective tonsillectomy. The patients were divided into four groups according to indication for surgery. Aerobic and anaerobic cultures from the tonsillar surface and core were analyzed.

RESULTS

FN was detected less frequently in the tonsillar cores of RT patients (22%) than in those of patients without RT (30%) (p=0.44). FN detection frequencies ranged between 20% and 35% across the four groups. Betahaemolytic streptococci groups A/C/G (BHS) were detected significantly (p=0.007) more often in the RT group than in the halitosis/PSTS group.

CONCLUSION

A possible role of FN in RT was not substantiated. Our results indicate that FN is likely to be part of the normal flora. The tonsillar surface and core flora carry considerable interpersonal diversity, but is very similar bilaterally in each individual. Other factors seem to play a major role in the development of the represented tonsillar diseases.

FUNDING

Not relevant.

TRIAL REGISTRATION

The study was approved by The Research Ethics Committee of Aarhus County (no. 20050034).

Severe pneumonia and jaundice in a young man: an atypical presentation of an uncommon disease

We present a patient with an atypical presentation of Fusobacterium infection, the genus responsible for Lemierre's syndrome. This syndrome, which often affects healthy, young people and can be fatal if not recognized and treated early, is defined as a history of recent oropharyngeal infection with clinical or radiological evidence of internal jugular vein thrombosis and isolation of anaerobic pathogens, mainly Fusobacterium necrophorum. The history, presentation, investigations and management of the patient are described and then contrasted with the existing literature surrounding Lemierre's syndrome, once termed the 'forgotten disease'.

A case of pyogenic liver abscess infected with Fusobacterium necrophorum depicted by microscopy and confirmed by tissue culture

A 40-year-old man was admitted with a continuous high grade fever accompanying a relatively large solitary liver abscess with septations. A puncture of the abscess revealed gram-negative rods that could be identified histologically as Fusobacterium necrophorum, which was later confirmed by tissue culture. The patient was switched to meropenem and penicillin, and cured of the infection. Fusobacterium necrophorum is a rare bacterium causing potentially fatal liver abscesses in humans. Clinicians should bear Fusobacterium necrophorum in mind when treating patients with an enlarged solitary liver abscess.

Fusobacterium necrophorum bacteremic tonsillitis: 2 Cases and a review of the literature

Fusobacterium necrophorum can cause endemic pharyngitis and the Lemierre syndrome. Four previous case reports and one epidemiologic study have documented that some F. necrophorum pharyngitis patients develop bacteremia without developing the complete Lemierre syndrome. We report two more patients who have bacteremic F. necrophorum pharyngitis. We summarize the clinical presentation of these six patients. All received early diagnosis and excellent response to antibiotics. We speculate that prompt antibiotic treatment may have prevented the more serious Lemierre syndrome. Adolescents and young adults who present with significant pharyngotonsillitis and bacteremic symptoms should have blood cultures and receive antibiotic regimens that treat F. necrophorum. Recognition of such patients might prevent Lemierre syndrome.

Lemierre's syndrome mimicking leptospirosis

Lemierre's syndrome is a suppurative thrombophlebitis involving the internal jugular vein, most commonly associated with Fusobacterium necrophorum, usually a complication of oropharyngeal infections. This syndrome is rare and is often overlooked. We present a case of sepsis mimicking initially severe leptospirosis (Weil's disease) due to acute febrile illness with multiorgan failure and hyperbilirubinemia. Finally, blood cultures revealed Fusobacterium necrophorum and computed tomography (CT) demonstrated bilateral pulmonary nodules and a thrombus in the right internal jugular vein. Early clinical suspicion is crucial so that appropriate diagnostic investigation and antibiotic therapy can be initiated to minimize the risk of life-threatening complications.

Lemierre's syndrome: Still an important clinical entity

We report a case of Lemierre's syndrome caused by Fusobacterium necrophorum and discuss characteristics of this potentially fatal condition which, though rare, may have a rising frequency. Familiarity with the signs and symptoms of Lemierre's syndrome is therefore of great importance.

[Fusobacterium necrophorum: from tonsillitis to Lemierre's syndrome]

Fusobacterium necrophorum plays a role in non-GAS-tonsillitis in adolescents and probably also in small children with recurrent otitis media. Anaerobic culture on selective anaerobic media is recommended to detect F. necrophorum and treat such patients. Denmark sees at least 20 annual cases of Lemierre's syndrome with a mortality reaching 9%. Early suspicion of Lemierre's syndrome in adolescents with non-GAS-tonsillitis, who develop septicaemia, pulmonary symptoms and unilateral swelling on the neck, is mandatory to lower morbidity and mortality.

[Can anaerobic culture of throat swabs prevent Lemierre's syndrome?]

Six cases of Lemierre's syndrome were reported from 2004 to 2007 at Viborg Hospital, corresponding to 33 cases per year in Denmark. All six patients were healthy younger persons presenting with a suspected bacterial tonsillitis which had been found strep A antigen negative. Fusobacterium necrophorum was found in throat swabs by anaerobic culture on selective media and/or by real-time PCR. We recommend that all patients 10 to 40 years of age with strep A antigentest negative bacterial tonsillitis have throat swabs anaerobically cultured on selective media. We believe early identification and therapy may prevent progression to Lemierre's syndrome.

Lemierre's syndrome followed by acute respiratory distress syndrome successfully rescued by antibiotics and hemoperfusion with polymyxin B-immobilized fiber

Lemierre's syndrome is characterized by a primary oropharyngeal infection in a young healthy person who subsequently develops septic thrombophlebitis of the internal jugular vein and metastatic abscesses. We here report an uncommonly severe case of Lemierre's syndrome with acute respiratory distress syndrome (ARDS), in which polymyxin B-immobilized fiber (PMX) was used as supportive therapy. A 30-year-old, previously healthy man presented with sore throat, fever, rigor, and dyspnea. Chest computed tomography scan revealed multiple bilateral peripheral pulmonary nodules with small bilateral pleural effusions. The patient's condition rapidly deteriorated into ARDS after admission. Intubation followed by mechanical ventilation was required, and hemoperfusion with PMX was useful in alleviating the patient's condition. Isolation of Fusobacterium necrophorum from the blood culture and the contrast-enhanced scan revealed thrombosis and thrombophlebitis in the left internal jugular vein. The patient was diagnosed with Lemierre's syndrome, and an alternative treatment regimen with prolonged administration of ampicillin, clindamycin, and metronidazole resulted in improvement of the patient's respiratory function and general condition. Our case indicated that PMX might be an effective supportive therapy in severe cases of Lemierre's syndrome with ARDS that possessed no indication of surgical interventions.