Detection of Fusobacterium necrophorum subsp. funduliforme in tonsillitis in young adults by real-time PCR

Abstract

Throat swabs from 61 patients, aged 18-32 years, with non-streptococcal tonsillitis (NST) and 92 healthy controls were examined for the presence of Fusobacterium necrophorum DNA using a novel TaqMan-based real-time quantitative PCR assay for F. necrophorum subspecies. The assay was based on the gyrB subunit gene, and detected F. necrophorum DNA in 48% of patients with NST and in 21% of controls (p <0.001). F. necrophorum subsp. funduliforme was the only subspecies found in both patients and controls. The load of F. necrophorum DNA on swabs from patients with NST was significantly higher than that on swabs from controls (p <0.001). Furthermore, patients with recurrent NST had a significantly higher load of F. necrophorum DNA compared to patients with acute NST (p 0.04). In addition, 26 patients with tonsillitis and group C streptococci (GCS) had a significantly higher load of F. necrophorum DNA compared to the NST group (p <0.001). It was concluded that F. necrophorum subsp. funduliforme is present in small numbers as part of the normal human throat flora, and that F. necrophorum in large quantities may cause tonsillitis, especially recurrent tonsillitis. In addition, the study suggests that the concomitant presence of GCS may aggravate F. necrophorum tonsillitis.

Factor H Binding as a Complement Evasion Mechanism for an Anaerobic Pathogen, Fusobacterium necrophorum

“…However, there is actually no supporting data and this is under reevaluation (24). A recent study, using molecular biology tools for the detection of F. necrophorum, showed that fusobacteria could be part of normal flora with a low carriage percentage in the control cohort (15). This raises the question of why certain fusobacterial strains become pathogenic and cause invasive infections.…”

“…Binding sites have been identified on the N-terminal (SCRs 1-7), C-terminal (SCRs [15][16][17][18][19][20], or in the middle part of fH (SCRs 8 -15) (14,26,27). To localize the binding site for F. necrophorum on fH, we used three different assays.…”

“…necrophorum is a pathogen causing local infections (e.g., dental infections, acute or chronic tonsillitis, and invasive pathology) (1,15,35,36). Its role has also been discussed in Noma that affects malnourished young children as a unilateral ulcer of the cheek rapidly progressing to perforation (37).…”

A Sore Throat—Potentially Life-Threatening?

“…Chest examination disclosed tachypnea, labored breathing, and bilateral rales with decreased breath sounds and dullness to percussion in the bases. Initial laboratory testing revealed a white blood cell count of 7,400/mm 3 , Hgb 9.5 g/dl, Hct 26.5%, platelets 42,000/mm 3 . ABG showed pH of 7.43, pCO 2 28, pO 2 63, on 40% FIO 2 .…”

“…F. necrophorum is considered by some to be the second most common cause of bacterial sore throat after group A beta hemolytic streptococci. [1][2][3][4] Lemierre's syndrome, which also is known as postanginal septicemia and a form of necrobacillosis, was first reported by Lemierre in 1936. 5 Classic LS is characterized by four criteria, which include primary infection in the oropharynx, septicemia documented by at least one positive blood culture, clinical or radiographic evidence of internal jugular vein thrombosis, and at least one metastatic focus.…”