RT-PCR: Real-Time polymerase chain reaction; RNA-ISH: RNA in situhybridization; TP: True Positive; FN: False Negative; FP: False Positive; TN: True Negative; F. nucleatum : Fusobacterium nucleatum ; B. fragilis : Bacteroides fragilis ; E. coli : Escherichia coli ; PPV: Positive Predictive Value; NPV: Negative Predictive Value; PLR: Positive Likelihood Ratio; NLR: Negative Likelihood Ratio.