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Introduction: Clostridioides difficile (C. difficile) is a nosocomial bacterial pathogen that causes antibiotic-associated diarrhea mediated by cellular exotoxins secreted into the intestine during bacterial growth. Multilocus sequence typing (MLST) and PCR ribotyping are the main molecular typing for C. difficile. Whole genome sequencing (WGS) core genome multilocus sequence typing (cgMLST) was developed for genetic evolution and outbreak investigation of C. difficile with higher precision and accuracy. Methods: A total of 699 whole (complete and draft) genome sequences of distinct C. difficile strains were used in this study to identify core gene set (2469 core genes) and the cgMLST scheme for the phylogeny analysis of C. difficile. This cgMLST pipeline was then carried the Chinese Pathogen Identification Net (China PIN) for surveillance of C. difficile in China. Within the China PIN, 195 WGS of C. difficile and an outbreak of CDI with 12 WGS of C. difficile were used to evaluate the cgMLST pipeline. Results: The result displayed that mostly tested C. difficile isolates could be successfully divided into 5 classic clades and the outbreak event was also successfully identified. Discussion: The results are meaningful and offer a practicable pipeline for a national-wide surveillance of C. difficile in China. [ABSTRACT FROM AUTHOR]

Objectives: The aim of this study was to verify the accuracy of using myocardial contrast echocardiography (MCE), to quantify regional myocardial blood flow (MBF), and to evaluate myocardial viability in comparison to that measured by radiolabeled microsphere and pathologic examination. Methods: Epicardial MCE was obtained in five myocardial ischemic dogs with constant microbubble intravenous infusion. After the video intensity (VI, y) versus pulsing interval plots derived from each myocardial pixel were fitted to an exponential function: y = A(1 − e−βt), the MBF was calculated as the product of A (microvascular cross-sectional area or myocardial blood volume) and β (mean myocardial microbubble velocity). The MBF was also obtained by radiolabeled microsphere method. Results: The MBF derived by radiolabeled microsphere method in the normal, ischemic, and infarcted region was 1.5 ± 0.3, 0.7 ± 0.3, and 0.3 ± 0.2 ml/min per gram, respectively; P < 0.01. The product of A and β in those regions was 52.5 ± 15.1, 24.4 ± 3.9, and 3.7 ± 3.8, respectively; P < 0.01. The normalized product of A and β correlated well with normalized MBF (r = 0.81, P = 0.001). Conclusion: Our initial study demonstrated that MCE has an ability to assess MBF in ischemic myocardium in the experimental model. It may provide a potential capability to detect viable myocardium noninvasively after total persistent coronary occlusion in the clinical setting. (ECHOCARDIOGRAPHY, Volume 21, July 2004) [ABSTRACT FROM AUTHOR]