Droplet Digital PCR for Acinetobacter baumannii Diagnosis in Bronchoalveolar Lavage Samples from Patients with Ventilator-Associated Pneumonia.

Advanced diagnostic technologies have made accurate and precise diagnosis of pathogens easy. Herein, we present a new diagnostic method, droplet digital PCR (ddPCR), to detect and quantify Acinetobacter baumannii in mini bronchoalveolar lavage (mini-BAL) samples. A. baumannii causes ventilator-associated pneumonia (VAP), a severe healthcare infection affecting patients' lungs. VAP carries a high risk of morbidity and mortality, making its timely diagnosis crucial for prompt and effective management. Methodology. The assay performance was evaluated by comparing colonization data, quantitative culture results, and different generations of PCR (traditional PCR and Real-Time PCR-qPCR Taqman® and SYBR® Green). The ddPCR and qPCR Taqman® prove to be more sensitive than other molecular techniques. Reasonable analytical specificity was obtained with ddPCR, qPCR TaqMan®, and conventional PCR. However, qPCR SYBR® Green technology presented a low specificity, making the results questionable in clinical samples. DdPCR detected/quantified A. baumanni in more clinical samples than other methods (38.64% of the total samples). This emerging ddPCR technology offers promising advantages such as detection by more patients and direct quantification of pathogens without calibration curves.

Quantitative Assessment of the Efficacy of Two Different Single-file Systems in Reducing the Bacterial load in Oval-Shaped Canals: A Clinical Study.

INTRODUCTION: This randomized clinical study compared the in vivo antibacterial efficacy of Reciproc Blue (RB), XP-endo Shaper (XP-S), and XP-endo Shaper associated with XP-endo Finisher (XP-F) systems in infected oval-shaped root canals with primary apical periodontitis. METHODS: In this study, 28 human teeth with a single root and a single canal were randomly assigned to 2 groups according to the instrumentation technique: group 1, RB (n = 14) and group 2, XP-endo (XP-S and XP-F, n = 14). The single-rooted teeth were prepared by reciprocating and rotary nickel-titanium instruments with 5.25% sodium hypochlorite irrigation. Samples were collected from the canal at the baseline (S1), after chemomechanical preparation (S2), and after XP-F instrumentation (S3). The DNA extracts were subjected to quantitative analysis for total bacterial counts by quantitative real-time polymerase chain reaction. The data were analyzed using the analysis of variance test, and the level of significance was set at 5%. RESULTS: All samples tested positive for the presence of bacteria at baseline, and the bacterial counts substantially reduced after treatment procedures (P < .01). The results showed no statistical difference between RB and XP-S instrumentation with respect to the bacterial reduction (P > .05). A marked bacterial reduction was observed after the use of the XP-F instrument (P < .01). CONCLUSIONS: The XP-S and RB systems sharply reduced the bacterial load in oval-shaped root canals with primary apical periodontitis. XP-F used as a supplementary instrument to chemomechanical preparation promoted a significantly higher bacterial reduction.