Oral Microbiome in Patients with Oesophageal Squamous Cell Carcinoma.

To investigate the oral microflora of patients with oesophageal squamous cell carcinoma (ESCC), saliva samples were collected from 20 patients with ESCC and 21 healthy controls. The V3-V4 region of 16S rDNA was amplified and sequenced by the Illumina MiSeq high-throughput sequencing platform. The final sequences were used for OTU analysis. Alpha and beta diversity analysis showed that the bacterial diversity and richness of the ESCC group were lower than those of the control group, while the variability of the ESCC group was higher than that of the control group. According to the Metastats difference analysis and LEfSe analysis, the high risk of ESCC may be related to Actinomyces and Atopobium, while the healthy control group is closely related to Fusobacterium and Porphyromonas (the analysis was performed at the genus level). The establishment of the relationship between oral microbiota and risk of ESCC may lead to significant advances in understanding the aetiology of cancer and may open a new research paradigm for cancer prevention.

Detection and Genomic Characterization of a Morganella morganii Isolate From China That Produces NDM-5.

The increasing prevalence and transmission of the carbapenem resistance gene bla NDM-5 has led to a severe threat to public health. So far, bla NDM-5 has been widely detected in various species of Enterobacterales and different hosts across various cities. However, there is no report on the bla NDM-5- harboring Morganella morganii. In January 2016, the first NDM-5-producing Morganella morganii L241 was found in a stool sample of a patient diagnosed as recurrence of liver cancer in China. Identification of the species was performed using 16S rRNA gene sequencing. Carbapenemase genes were identified through both PCR and sequencing. To investigate the characteristics and complete genome sequence of the bla NDM-5-harboring clinical isolate, antimicrobial susceptibility testing, S1 nuclease pulsed field gel electrophoresis, Southern blotting, transconjugation experiment, complete genome sequencing, and comparative genomic analysis were performed. M. morganii L241 was found to be resistant to broad-spectrum cephalosporins and carbapenems. The complete genome of L241 is made up from both a 3,850,444 bp circular chromosome and a 46,161 bp self-transmissible IncX3 plasmid encoding bla NDM-5, which shared a conserved genetic context of bla NDM-5 (ΔIS3000-ΔISAba125-IS5-bla NDM-5-ble-trpF-dsbC-IS26). BLASTn analysis showed that IncX3 plasmids harboring bla NDM genes have been found in 15 species among Enterobacterales from 13 different countries around the world thus far. In addition, comparative genomic analysis showed that M. morganii L241 exhibits a close relationship to M. morganii subsp. morganii KT with 107 SNPs. Our research demonstrated that IncX3 is a key element in the worldwide dissemination of bla NDM-5 among various species. Further research will be necessary to control and prevent the spread of such plasmids.