No abstract

The sensitivity and utility of liquid biopsy in clinical practice requires some improvement. The aim of the present study was to improve the detection of epidermal growth factor (EGFR) and cellular tumor antigen p53 (TP53) mutations in liquid biopsies from patients with advanced non-small cell lung cancer (NSCLC) by combining plasma, sputum and urine samples under the same sequencing platform. Plasma, sputum and urine samples, and tumor tissues were obtained from 50 patients with NSCLC and were analyzed using next-generation sequencing. The sensitivity of EGFR-sensitive mutation detection was 84% in plasma, 63% in sputum, 28% in urine, and 91% when combining the three liquid samples (P<0.001). The sensitivity of TP53 mutation detection increased from 87% in plasma to 94% when the three samples were combined (P<0.001). The sensitivity of EGFR or TP53 mutations detection was higher in patients with multiple metastatic sites compared with patients ≤1 metastatic site. In addition, the progression free survival (PFS) rates obtained following analysis of the three samples independently in patients with EGFR sensitizing mutations were similar, and were 9.0 months in the tissue sample, 7.5 months in plasma, 7.9 months in the sputum and 7.3 months in urine (P=0.721). The PFS of patients with TP53 mutations was shorter compared with patients without TP53 mutations and was as follows: Tissue, 8.2 months compared with 10.2 months (P=0.412); plasma, 8.4 months compared with 10.2 months (P=0.466); sputum, 8.3 months compared with 9.1 months (P=0.904); and when combined, 8.8 months compared with 10.3 months (P=0.599). The combination of plasma, sputum and urine increased the detection of EGFR or TP53 mutation with higher sensitivity, and may improve the predictive value of personalized treatment.

Acinetobacter baumannii is an important pathogen of nosocomial infections. Nosocomial outbreaks caused by antibiotic-resistant A. baumannii remain a significant challenge. Understanding the antibiotic resistance mechanism of A. baumannii is critical for clinical treatment. The purpose of this study was to determine the whole-genome sequence (WGS) of an extensively drug-resistant (XDR) A. baumannii strain, XDR-BJ83, which was associated with a nosocomial outbreak in a tertiary care hospital of China, and to investigate the antibiotic resistance mechanism of this strain. The WGS of XDR-BJ83 was performed using single-molecule real-time sequencing. The complete genome of XDR-BJ83 consisted of a 4,011,552-bp chromosome and a 69,069-bp plasmid. The sequence type of XDR-BJ83 was ST368, which belongs to clonal complex 92 (CC92). The chromosome of XDR-BJ83 carried multiple antibiotic resistance genes, antibiotic efflux pump genes, and mobile genetic elements, including insertion sequences, transposons, integrons, and resistance islands. The plasmid of XDR-BJ83 (pBJ83) was a conjugative plasmid carrying type IV secretion system. These results indicate that the presence of multiple antibiotic resistance genes, efflux pumps, and mobile genetic elements is likely associated with resistance to various antibiotics in XDR-BJ83.