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.

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.

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.

High prevalence of pharyngeal bacterial pathogens among healthy adolescents and young adults.

The pharyngeal mucosa can be colonized with bacteria that have potential to cause pharyngotonsillitis. By the use of culturing techniques and PCR, we aimed to assess the prevalence of bacterial pharyngeal pathogens among healthy adolescents and young adults. We performed a cross-sectional study in a community-based cohort of 217 healthy individuals between 16 and 25 years of age. Samples were analyzed for Group A streptococci (GAS), Group C/G streptococci (SDSE), Fusobacterium necrophorum, and Arcanobacterium haemolyticum. Compared to culturing, the PCR method resulted in more frequent detection, albeit in most cases with low levels of DNA, of GAS (20/217 vs. 5/217; p < 0.01) and F. necrophorum (20/217 vs. 8/217; p < 0.01). Culturing and PCR yielded similar rates of SDSE detection (14/217 vs. 12/217; p = 0.73). Arcanobacterium haemolyticum was rarely detected (3/217), and only by PCR. Overall, in 25.3% (55/217) of these healthy adolescents and young adults at least one of these pathogens was detected, a rate that is higher than previously described. Further studies are needed before clinical adoption of PCR-based detection methods for pharyngeal bacterial pathogens, as our findings suggest a high incidence of asymptomatic carriage among adolescents and young adults without throat infections.

Leukotoxin production by Fusobacterium necrophorum strains in relation to severity of liver abscesses in cattle.

Fusobacterium necrophorum, a Gram-negative anaerobe, is the primary etiologic agent of liver abscesses of beef cattle. The bacterium, a member of the microbial community of the rumen, travels to the liver via portal circulation to cause abscesses. The severity of liver abscesses vary from mild with one or two small abscesses to severe with medium to large multiple abscesses. Leukotoxin, a secreted protein, is the critical virulence factor involved in the infection. Our objective was to compare leukotoxin production between strains of F. necrophorum isolated from mild and severe liver abscesses collected from slaughtered cattle. The quantification of leukotoxin was based on assays to measure cytotoxicity and protein antigen concentration. One-hundred strains, 50 from mild and 50 from severe abscesses, were utilized in the study. Cell-free supernatants were prepared from cultures grown in anaerobic broth at 9 and 24 h incubations. The leukotoxic activity was quantified by measuring cytotoxicity based on the release of lactic dehydrogenase from bovine lymphocyte cells, BL3, treated with the culture supernatant. Leukotoxin protein concentration was quantified by a sandwich ELISA assay with a leukotoxin-specific monoclonal antibody as the capture antibody. The leukotoxin activity and concentration were highly variable among the strains within each severity of liver abscesses. Although the leukotoxic activity was unaffected by incubation time, leukotoxin protein concentration was consistently higher at 24 h compared to 9 h incubation. Strains from severe liver abscesses had significantly higher leukotoxic activity and higher protein concentration compared to strains from mild liver abscesses (P < 0.0001) at both 9 and 24 h culture supernatants. Across all strains, the correlation coefficients between leukotoxic activity and leukotoxin concentration at 9 and 24 h were 0.14 (P = 0.17) and 0.47 (P < 0.0001), respectively. In conclusion, strains isolated from severe liver abscesses had significantly higher leukotoxic activities and leukotoxin protein concentrations compared to strains isolated from mild liver abscesses.

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.

Lemierre's syndrome: a forgotten life-threatening entity.

Lemierre's syndrome is a very rare but potentially fatal condition. It mainly affects adolescents and young adult males, and usually arises as a serious complication of pharyngitis or peritonsillar abscess. It is characterised by the triad of internal jugular vein septic thrombophlebitis, septic emboli (mostly pulmonary) and the isolation of the agent 'Fusobacterium necrophorum' in sterile fluids. In this report, it is described a case in which the nonspecific and subtle clinic made the diagnosis difficult to reach. In fact, only the dissociation between flu-like symptoms and the presence of significant changes in the blood tests (suggestive of acute bacterial infection), led to the request for imaging tests, which proved to be essential for the final diagnosis and subsequent control of the disease. This case report aims to increase the awareness among Ear, Nose and Throat (ENT) residents, paediatricians and family doctors about the existence of this entity and its potential life-threatening nature.

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.

Late presentation of 'Lemierre's syndrome': how a delay in seeking healthcare and reduced access to routine services resulted in widely disseminated Fusobacterium necrophorum infection during the global COVID-19 pandemic.

The SARS-CoV-2 outbreak has disrupted the delivery of routine healthcare services on a global scale. With many regions suspending the provision of non-essential healthcare services, there is a risk that patients with common treatable illnesses do not receive prompt treatment, leading to more serious and complex presentations at a later date. Lemierre's syndrome is a potentially life-threatening and under-recognised sequela of an oropharyngeal or dental infection. It is characterised by septic embolisation of the gram-negative bacillus Fusobacterium necrophorum to a variety of different organs, most commonly to the lungs. Thrombophlebitis of the internal jugular vein is frequently identified. We describe an atypical case of Lemierre's syndrome involving the brain, liver and lungs following a dental infection in a young male who delayed seeking dental or medical attention due to a lack of routine services and concerns about the SARS-CoV-2 outbreak.

Lemierre's syndrome in the pediatric population: Trends in disease presentation and management in literature.

OBJECTIVE: This study aims to examine literature on Lemierre's Syndrome (LS) in the pediatric population over time in order to describe patterns in disease progression, management, and prognosis. In addition, this study assesses specific rate of literature output and the location of research over the past 10 years. METHODS: A literature review was conducted through two databases, PubMed.gov and PMC. A search was conducted using the keywords "Lemierre syndrome" and "postanginal sepsis." Literature was primarily reviewed for demographic, radiographic, and clinical data. Articles were included in the study if they were published in English and within the last 10 years. All types of research studies were recorded, however primary data collection came from case reports and series. Publications were grouped into two time periods: 2009-2013 and 2014-2019, allowing for comparison of various characteristics between these two groups. RESULTS: A total of 124 research studies on LS met inclusion criteria and were reviewed. Of these, 98 case reports (79.0%) were examined. Disease Characteristics: Fusobacterium necrophorum was the most common precipitating pathogen isolated from cultures (66.2%). The main primary treatment modalities used were antimicrobials, surgery, anticoagulation, or a combination of these treatments. A total of 63.9% of the case reports indicated use of anticoagulation at some point during treatment. Publication Trends: The number of published studies has not significantly changed in the last decade, with a non-statistically significant decline of 5.6%, when comparing 2014-2019 to 2009-2013 (p = 0.21). Case reports/series were the most common study design (82.2% vs 69.5%) and level of evidence for published studies continued to be stable (level 4-5) through the years (86.9%). The number of publications within an international journal vs US based journal has also remained steady during both time periods (p = 0.698). CONCLUSION: LS is an uncommon condition but one that is important for physicians to be aware of in the pediatric population. Treatment regimens including antibiotics and anticoagulation have remained stable through the past 10 years, however the efficacy of anticoagulation in treating LS continues to be debated. Though LS is considered a severe illness with potentially life threatening complications, publications on this topic, in pediatrics specifically, have decreased within the past five years.

Septic Shock Caused by Fusobacterium Necrophorum after Sexual Intercourse during Recovery from Infectious Mononucleosis in an Adolescent: A Case Report.

BACKGROUND: Infectious mononucleosis (IM) develops after primary infection with Epstein-Barr virus. We report a case of septic shock from pelvic inflammatory disease caused by Fusobacterium necrophorum in an adolescent after sexual intercourse during recovery from IM. CASE: A 17-year-old girl with a 7-day history of fever was diagnosed with IM. During follow-up, she developed lower abdominal pain and high fever after sexual intercourse and was transferred to our hospital. She was in shock and had a right ovarian abscess. Emergency laparotomy, drainage, and right adnexectomy were performed. F necrophorum was subsequently detected in blood and abscess cultures.

[Gynecological Lemierre's syndrome: A case report and literature review]. / Syndrome de Lemierre inversé : à propos d'un cas et revue de la littérature.

INTRODUCTION: Lemierre's syndrome is defined as an oropharyngeal infection due to Fusobacterium necrophorum, associated with septic thrombophlebitis of the internal jugular vein. The uncommon pelvic variant of the syndrome is a rare condition, poorly described in literature. CASE REPORT: We report a case of gynecological Lemierre's syndrome in a 19-year-old woman after a first sexual intercourse, who presented acute respiratory failure, left internal iliac vein thrombosis with pulmonary embolism, in the setting of salpingitis and F. necrophorum bacteriemia. CONCLUSION: Gynecological Lemierre's syndrome is a rare and unrecognized condition, which could be lethal. Early recognition of the disorder enables initiation of appropriate antibiotic therapy for 4 to 6 weeks, and discussion of anticoagulant therapy which indications are not yet well defined.

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.