The impact of social restrictions on the incidence and microbiology of severe acute tonsillitis.

INTRODUCTION: We aimed to explore the impact of social distancing on the incidence, severity and microbiology of patients with acute tonsillitis (AT). METHODS: In this single-centre study, we retrospectively included all patients with AT referred to the Ear-Nose-Throat Department, Aarhus University Hospital, Denmark, in the two years preceding versus the two years after the COVID-19 lockdown in Denmark (11 March 2020). RESULTS: In total, 425 patients were included. The incidence of AT was significantly lower in the post-lockdown period (n = 128) than in the pre-lockdown period (n = 297) (p less-than 0.001). Reduced incidence was observed across all age groups. No significant differences were found in patient characteristics between periods. The proportion of hospitalised patients was significantly lower in the post- than in the pre-lockdown period (36% versus 25%, p = 0.032). Prevalent culture findings were Streptococcus pyogenes (15%), S. anginosus group (11%) and Fusobacterium necrophorum (5%). No statistically significant differences in the relative prevalence of individual bacteria were found between periods. CONCLUSIONS: The incidence of patients with AT referred to hospital decreased by 57% in the two-year period after the COVID-19 lockdown compared with the period leading up to the lockdown. Our findings suggest that this decrease mirrored a general decline in AT incidence rather than altered referral patterns. FUNDING: None. TRIAL REGISTRATION: The study was approved by the Danish Data Protection Agency (#1-16-02-134-23) and the Danish Patient Safety Authority (#1-45-70-41-23).

Association of pathogenic determinants of Fusobacterium necrophorum with bacteremia, and Lemierre's syndrome.

Fusobacterium necrophorum is a Gram-negative anaerobic bacterium responsible for localized infections of the oropharynx that can evolve into bacteremia and/or septic thrombophlebitis of the jugular vein or peritonsillar vein, called Lemierre's syndrome. To identify microbial genetic determinants associated with the severity of this life-threatening disease, 70 F. necrophorum strains were collected and grouped into two categories according to the clinical presentation: (i) localized infection, (ii) bacteremia with/without Lemierre's syndrome. Comparative genomic analyses revealed two clades with distinct genetic content, one clade being significantly enriched with isolates from subjects with bacteremia. To identify genetic determinants contributing to F. necrophorum pathogenicity, genomic islands and virulence factor orthogroups (OVFs) were predicted. The presence/absence profiles of OVFs did not group isolates according to their clinical category, but rather according to their phylogeny. However, a variant of lktA, a key virulence factor, with a frameshift deletion that results in two open reading frames, was associated with bacteremia. Moreover, a genome-wide association study identified three orthogroups associated with bacteremic strains: (i) cas8a1, (ii) a sodium/solute symporter, and (iii) a POP1 domain-containing protein. Further studies must be performed to assess the functional impact of lktA mutation and of these orthogroups on the physiopathological mechanisms of F. necrophorum infections.

Resistance of zebu cattle (Bos indicus) to colonization by major ruminant hoof pathogens.

Zebu cattle (Bos indicus) is reported to be more resistant towards harmful environmental factors than taurine cattle (Bos taurus). A few hundred zebu cattle are kept in Switzerland and in contrast to the Swiss indigenous breeds, infectious hoof disease in zebu is not observed. Therefore, we compared the prevalence of three ruminant hoof pathogens in zebu and taurine cattle. These included Treponema spp., Fusobacterium necrophorum and Dichelobacter nodosus which are associated with bovine digital dermatitis (BDD), different bovine hoof diseases and ovine footrot, respectively. Interdigital swabs and punch biopsies from hind feet of slaughter animals were tested for the three pathogens by PCR. Sixty zebu from eight farms were compared to a convenience sample of 20 taurine cattle from 17 farms. Treponema spp. associated with BDD were not detected in zebu while 23 % of animals and 50 % of farms were positive for benign D. nodosus, with results indicating environmental contamination rather than colonization. Taurine cattle showed 35 % of animals and 41 % of farms positive for T. phagedenis while 90 % of animals and 94 % of farms were colonized by D. nodosus as indicated by a 500-fold higher bacterial load than in zebu. The difference in prevalence of the two pathogens between zebu and taurine cattle was highly significant. F. necrophorum was as well only detected in taurine cattle with values of 15 % of animals and 17.7 % of farms, being significantly different at the animal level. Furthermore, genetic analysis of Swiss zebu indicates high genomic diversity and clear separation from taurine cattle. This is the first evidence that zebu show resistance towards colonization by bacterial hoof pathogens in contrast to taurine cattle.

Metagenomic next-generation sequencing reveals co-infection with Legionella pneumophila and Fusobacterium necrophorum in a patient with severe pneumonia: a case report.

BACKGROUND: Legionella pneumonia is one of the most severe types of atypical pneumonia, impairing multiple organ systems, posing a threat to life. Diagnosing Legionella pneumonia is challenging due to difficulties in culturing the bacteria and limitations in immunoassay sensitivity and specificity. CASE PRESENTATION: This paper reports a rare case of sepsis caused by combined infection with Legionella pneumophila and Fusobacterium necrophorum, leading to respiratory failure, acute kidney injury, acute liver injury, myocardial damage, and electrolyte disorders. In addition, we systematically reviewed literature on patients with combined Legionella infections, analyzing their clinical features, laboratory results and diagnosis. CONCLUSIONS: For pathogens that require prolonged incubation periods and are less sensitive to conventional culturing methods, metagenomic next-generation sequencing (mNGS) can be a powerful supplement to pathogen screening and plays a significant role in the auxiliary diagnosis of complex infectious diseases.

Lemierre's syndrome complicating multiple organ failure caused by Fusobacterium necrophorum subsp. funduliforme F1260: Case report and review.

We described a case of a 24-year-old man with multiple organ failure caused by Fusobacterium necrophorum subsp. funduliforme F1260. This is the first described case of Lemierre's syndrome with multiple organ failure due to F. necrophorum subsp. funduliforme F1260 in an adult in China. Our study highlights that there may be a risk of misdiagnosis based solely on typical manifestations of internal jugular vein thrombophlebitis, metastatic lesions, and F. necrophorum isolated from blood cultures or normally sterile sites. Clinicians should be cognizant of the potential utility of metagenomic next-generation sequencing in facilitating early pathogen detection in severe infections, thus enabling timely and appropriate administration of antibiotics to reduce mortality rates and improve prognosis.

The Clinical Value of Cranial CT Venography for Predicting Fusobacterium necrophorum as the Causative Agent in Children with Complicated Acute Mastoiditis.

BACKGROUND AND PURPOSE: Fusobacterium necrophorum (F necrophorum) is an anaerobic bacteria that causes invasive head and neck infections in children. Several studies have demonstrated an increasing prevalence of F necrophorum as the causative agent in acute mastoiditis in children, with associated high rates of intracranial complications such as epidural abscess and sinus venous thrombosis, to name a few. F necrophorum requires a treatment protocol that differs from the empiric treatment that is tailored to more common pathogens (eg, group A streptococci, Streptococcus pneumonia), and hence expediting the diagnosis is important. For evaluating complicated acute mastoiditis in children, cranial CT venography remains the imaging study of choice in most medical centers due to its availability in emergency situations. Based on our clinical experience, our hypothesis is that children with F necrophorum-associated complicated acute mastoiditis can be differentiated from those with other etiologies using CT venography. MATERIALS AND METHODS: CT venography studies of 76 children hospitalized and treated for complicated acute mastoiditis were retrospectively reviewed. Retrieved imaging data included intracranial complications (epidural abscess, sinus venous thrombosis), cranial bone-related complications, and extracranial complications (subperiosteal abscess, temporomandibular joint abscess, and soft-tissue inflammation). The cohort was divided into children with F necrophorum-related disease (study group) and those with non-F necrophorum-related disease (control group). RESULTS: Thirty-seven children (49%) comprised the study group, and 39 children in whom the causative agents were other bacteria comprised the control group. There were significantly higher rates of complications in the study group: sinus venous thrombosis (P < .001), perisigmoid epidural abscess (P = .036), and extramastoid osteomyelitis (P < .001). Thrombosis in venous sites beyond the sigmoid sinus and jugular foramen (a pattern consistent with an otogenic variant of Lemierre syndrome) and emphysematous osteomyelitis were found only among children in the F necrophorum-related study group (32% and 22% accordingly). CONCLUSIONS: In children with complicated acute mastoiditis, CT venography findings of emphysematous osteomyelitis and/or thrombosis in venous sites beyond the sigmoid sinus and jugular foramen (a pattern consistent with the otogenic variant of Lemierre syndrome) should lead the radiologist to suggest F necrophorum-related mastoiditis.

Symptoms predictive of Fusobacterium necrophorum pharyngotonsillitis - an observational study of cases presenting to hospitals in Southern Sweden.

OBJECTIVES: Fusobacterium necrophorum is a common cause of pharyngotonsillitis. However, no guidelines exist on when to diagnose or treat it. We aimed to investigate associations between clinical criteria and F. necrophorum-positivity in pharyngotonsillitis and assess the predictive potential of a simple scoring system. METHODS: Pharyngotonsillitis patients who were tested for F. necrophorum (PCR) and presented to hospitals in the Skåne Region, Sweden, between 2013-2020 were eligible. Data were retrieved from electronic chart reviews and registries. By logistic regression we investigated associations between F. necrophorum-positivity and pre-specified criteria: age 13-30 years, symptom duration ≤ 3 days, absence of viral symptoms (e.g. cough, coryza), fever, tonsillar swelling/exudate, lymphadenopathy and CRP ≥ 50 mg/L. In secondary analyses, associated variables were weighted by strength of association into a score and its predictive accuracy of F. necrophorum was assessed. RESULTS: Among 561 cases included, 184 (33%) had F. necrophorum, which was associated with the following criteria: age 13-30, symptom duration ≤ 3 days, absence of viral symptoms, tonsillar swelling/exudate and CRP ≥ 50 mg/L. Age 13-30 had the strongest association (OR5.7 95%CI 3.7-8.8). After weighting, these five variables had a sensitivity and specificity of 68% and 71% respectively to predict F. necrophorum-positivity at the proposed cut-off. CONCLUSION: Our results suggest that F. necrophorum cases presenting to hospitals might be better distinguished from other pharyngotonsillitis cases by a simple scoring system presented, with age 13-30 being the strongest predictor for F. necrophorum. Prospective studies, involving primary care settings, are needed to evaluate generalisability of findings beyond cases presenting to hospitals.

Lemierre syndrome with pulmonary empyema caused by Prevotella intermedia.

Lemierre syndrome is a rare disease that is most often caused by Fusobacterium necrophorum We present a case caused by Prevotella intermedia in a young, healthy man, complicated by multiple cavitary lung lesions, loculated pleural effusions requiring chest tube placement and trapezius abscess. Our case highlights (a) P. intermedia as a rare cause of Lemierre syndrome and (b) clinical response to appropriate antimicrobial therapy may be protracted.

Case report: Metagenomics next-generation sequencing in the diagnosis of septic shock due to Fusobacterium necrophorum in a 6-year-old child.

Fusobacterium necrophorum (F. necrophorum) infection is rare in pediatrics. In addition, the detection time of F. necrophorum by blood culture is long, and the positive rate is low. Infection with F. necrophorum bacilli usually follows rapid disease progression, resulting in high mortality. In previous reports of F. necrophorum-related cases, the most dangerous moment of the disease occurred after the appearance of Lemierre's syndrome. We report an atypical case of a 6-year-old female patient who developed septic shock within 24 h of admission due to F. necrophorum infection in the absence of Lemierre's syndrome. F. necrophorum was identified in a blood sample by metagenomics next-generation sequencing (mNGS) but not by standard blood culture. The patient was finally cured and discharged after receiving timely and effective targeted anti-infection treatment. In the present case study, it was observed that the heightened virulence and invasiveness of F. necrophorum contribute significantly to its role as a primary pathogen in pediatric septic shock. This can precipitate hemodynamic instability and multiple organ failure, even in the absence of Lemierre's syndrome. The use of mNGS can deeply and rapidly identify infectious pathogens, guide the use of targeted antibiotics, and greatly improve the survival rate of patients.

Retropharyngeal abscess due to Fusobacterium necrophorum complicated by progressive internal carotid artery stenosis and multiple cranial nerve palsies.

BACKGROUND: A case of retropharyngeal abscess complicated by both artery and nerve injury has rarely been reported. METHODS: A 36-year-old woman suddenly presented with right eye visual loss, dilated pupil, reduced direct light reflex, ptosis and ocular motility disorder on the side of inflammation progression, and was diagnosed with retropharyngeal abscess due to Fusobacterium necrophorum. The patient was treated only with antibiotics and, no further surgery was necessary but tracheotomy. Four months later, MRA showed right ICA occlusion and left ICA stenosis. MRI revealed continuous spread of inflammation due to the abscess from the retropharyngeal to the intracranial space. RESULTS: These severe complications would be attributed to an endothelial damage to the arterial wall and an ischemic neuropathy caused by inflammation and thrombogenesis due to Fusobacterium necrophorum. CONCLUSIONS: This case should provide a better understanding of the mechanism of vascular and cranial nerve injury due to retropharyngeal infections, and highlights the need for early antibiotic therapy and repeated vascular evaluation.

Fusobacterium necrophorum an Underrecognized Cause of Petrous Apicitis Presenting with Gradenigo Syndrome: A Case Report.

BACKGROUND With the advent of antibiotics, petrous apicitis (PA), inflammation of the petrous temporal bone, has become a rare complication of otitis media. Even more uncommon is Gradenigo syndrome (GS), a result of PA, characterized by a triad of otitis media or purulent otorrhea, pain within the regions innervated by the first and second division of the trigeminal nerve, and ipsilateral abducens nerve palsy. Recent literature has demonstrated increasing reports of Fusobacterium necrophorum isolated in cases of GS. CASE REPORT A 21-year-old man presented with otalgia, reduced hearing, and severe headache. Examination revealed right-sided purulent otorrhea, anesthesia within the trigeminal nerve distribution, and an ipsilateral abducens nerve palsy. F. necrophorum was isolated from an ear swab and a blood culture. Computed tomography and magnetic resonance imaging (MRI) demonstrated otomastoiditis, PA, cavernous sinus thrombosis, and severe stenosis of the petrous internal carotid artery. He was treated with intravenous benzylpenicillin, underwent a mastoidectomy and insertion of a ventilation tube, and was started on a 3-month course of dabigatran. Interval MRI showed improved internal carotid artery caliber, persistent petrous apex inflammation, and normal appearance of both cavernous sinuses. Follow-up clinical review noted persistent abducens and trigeminal nerve dysfunction. CONCLUSIONS We identified 190 cases of PA; of these, 80 presented with the classic Gradenigo triad. Fusobacterium sp. were cultured in 10% of GS cases, making them the most frequent isolates. Due to the fastidious nature of F. necrophorum, it may be underrepresented in the historical literature, and we recommend that empiric antibiotics cover anaerobic organisms.

The first case report: diagnosis and management of necrotizing fusobacterium lung abscess via BALF next-generation sequencing.

BACKGROUND: Fusobacterium necrophorum (F. necrophorum)-induced necrotizing pneumonia is a rare but severe pulmonary infection. Insufficient microbiological detection methods can lead to diagnostic difficulties. METHODS: We report a case of F. necrophorum lung abscess diagnosed by next-generation sequencing (NGS) of bronchoalveolar lavage fluid (BALF). RESULTS: BALF-NGS detected F. necrophorum, guiding subsequent targeted antibiotic therapy. With active drainage and metronidazole treatment, the patient's condition was effectively treated. CONCLUSION: BALF-NGS is a valuable tool for the rapid diagnosis of infections caused by difficult-to-culture bacteria. It played a decisive role in the early identification of F. necrophorum, enabling timely and targeted antibiotic intervention. Early diagnosis and appropriate treatment are crucial for the management of F. necrophorum pneumonia.

Fusobacterium necrophorum intratonsillar abscess as a source of bacteremia in a patient with a history of substance abuse.

A 22-year-old male, with a history of recreational drug use, was admitted with a 24-hour history of sore throat, bilateral otalgia, fever, chills, sweats, and pain in the upper chest. The blood cultures were positive for Fusobacterium necrophorum. A thoracic and neck soft tissue computed tomography (CT) scan revealed an intratonsillar abscess and pulmonary septic emboli. Initial treatment with Piperacillin-tazobactam and Clindamycin was de-escalated after 5 days. The patient made a complete recovery after 22 days of antibiotic treatment.

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.

Lemierre syndrome: a diagnostic dilemma of critical care in the post-COVID era.

Lemierre syndrome (LS) is referred to as the 'forgotten Disease' owing to its rarity in the postantibiotic era with an estimated yearly incidence of 1/million population. The classic triad of LS includes internal jugular vein thrombosis, oropharyngeal infection and metastatic septic emboli. We present a case of typical LS with Fusobacterium and Prevotella infection, presenting with peritonsillar abscess and jugular vein thrombosis complicated by sepsis, acute hypoxic respiratory failure due to multiple pulmonary emboli and severe thrombocytopaenia in the absence of disseminated intravascular coagulation.

Peritonsillar abscess caused by Mycoplasma hominis and Fusobacterium necrophorum following oral sex.

Mycoplasma hominis is a bacterium that colonizes the genital tract of some females and males, as well as their respiratory tracts. Although only two cases of deep neck infection have been reported, the associations between the onset and sexual intercourse have not been reported. A healthy 19-year-old female was diagnosed with a left peritonsillar abscess. The patient had sexual intercourse with a new partner, including oral sex, two days prior to symptom onset. It was not known whether the male partner had urethritis symptoms. M. hominis and Fusobacterium necrophorum were isolated from the abscess culture. The patient's condition improved after drainage, and sulbactam ampicillin was switched to oral clindamycin.

Cryptogenic pyogenic liver abscess caused by Fusobacterium necrophorum in an immunocompetent patient.

Pyogenic liver abscesses are potentially fatal conditions that require prompt treatment with drainage and appropriate antimicrobial therapy. Fusobacterium necrophorum is a gram-negative rod that is found in the oral cavity, gastrointestinal tract and female genital tract. It is an extremely rare cause of liver abscess, particularly in the absence of risk factors or exposures. We describe an unusual case of a cryptogenic F. necrophorum hepatic abscess without a clear source despite extensive investigation in a young, immunocompetent patient without known risk factors or exposures for such an infection.

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.