Detection of a Mixed Infection in a Culture-Negative Brain Abscess by Broad-Spectrum Bacterial 16S rRNA Gene PCR

Abstract

We describe the identification of two bacterial pathogens from a culture-negative brain abscess by the use of broad-spectrum 16S rRNA gene PCR. Simultaneous detection of Fusobacterium nucleatum and Porphyromonas endodontalis was possible due to a 24-bp length difference of their partially amplified 16S rRNA genes, which allowed separation by high-resolution polyacrylamide gel electrophoresis.Broad-spectrum 16S rRNA gene PCR is a universal and highly versatile technology for the detection and identification of bacterial pathogens (11). Microbiological examination of life-threatening brain infections relies on microscopic examination and culture of abscess material. A recent study by Al Masalma et al. (1) explored an expanded technology applying multiple 16S rRNA fragment cloning and subsequent sequencing to analyze mixed floras in brain abscesses and found that the number of species associated with brain abscesses is much larger than previously noted. Based on a recent case and an in silico feasibility study, we present a modified technique for the molecular analysis of polymicrobial infections. After broadspectrum 16S rRNA gene amplification, amplicons are separated electrophoretically and excised from a polyacrylamide gel for subsequent sequence identification.

Rapid brain death caused by a cerebellar abscess with Fusobacterium nucleatum in a young man with drug abuse: a case report

“…Overall, the incidence of brain infections caused by strictly anaerobic bacteria may have been underestimated in the past, and this neglect might account for delays in diagnosis or failure to identify the causative pathogen. Albeit several reports about brain abscesses caused by Fusobacterium nucleatum report successful recovery under conservative management, delay of effective antibiotic treatment can increase the severity of disease and lethality [ 10 , 13 , 18 ].…”

Meningitis caused by Porphyromonas endodontalis detected by PCR amplification and sequencing of 16S rRNA genes direct from cerebrospinal fluid and cerebral tissue

“…Furthermore, to the best of our knowledge, this is the only case report in the literature of P. endodontalis causing meningitis. A case report of a mixed infection with P. endodontalis in a brain abscess has been described (Keller et al, 2010).…”

Heilaígerð - yfirlitsgrein

“…Þar má greina sýklafraeðilega orsök mikils meirihluta heilaígerða. 21,36 Á þetta sérstaklega við um aukinn fjölda loftfirrðra baktería sem greinst hafa í heilaígerðum. Líklegt er að þessi vitneskja muni á naestu árum breyta hugmyndum okkar um meingerð og meðferð heilaígerða.…”

“…Líklegt er að þessi vitneskja muni á naestu árum breyta hugmyndum okkar um meingerð og meðferð heilaígerða. [35][36][37] Blóðraektanir eru einungis jákvaeðar í um 30% tilfella 37 en aettu ávallt að vera framkvaemdar sé grunur um heilaígerð, jafnvel þó sjúklingur sé hitalaus. Einnig er mikilvaegt að raekta frá grunuðum upphafsstað sýkingar.…”