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.

Aim:To determine the correlation between mammography and ultrasound features of breast cancer with molecular subtypes and to calculate the predictive value of these features.Materials and Method:This is a prospective study of consecutive patients with breast cancer presenting between January 2016 and July 2017, who underwent mammography and/or ultrasound of breast and excision of the breast mass. Patients with contralateral breast mass, metastases, h/o prior cancer treatment, and other malignancies were excluded. On mammography, the presence or absence of microcalcification was noted. On ultrasound examination size, margins, microcalcification, posterior acoustic features, vascularity, and axillary nodes were assessed. Margins were categorized into circumscribed and non-circumscribed. Posterior acoustic features were classified into four categories: shadowing, enhancement, mixed, and no changes. Vascularity was assessed based on Adler's index into grades 0, 1, 2, and 3. Grades 0 and 1 were considered low and 2 and 3 were high.Results:Tumors with non-circumscribed margins and posterior acoustic shadowing were likely to be luminal A or B subtype of breast cancer [odds ratio (OR) 5.78; 95% confidence interval (CI) 3.68–9.80; P < 0.0001]. Tumors with non-circumscribed margins, posterior acoustic shadowing, and high vascularity were more likely to be luminal B subtype (OR 2.88; 95% CI 2–4.14; P- <0.0001). Tumors with microcalcification and posterior mixed acoustic pattern were strongly associated to be HER2-positive (OR 5.48; 95% CI 3.06–9.80; P < 0.0001). Tumors with circumscribed margins and posterior acoustic enhancement were highly suggestive of triple-negative breast cancer (OR 7.06; 95% CI 4.64–10.73; P < 0.0001).Conclusion:Microcalcification detected on mammography and certain ultrasound features such as circumscribed or non-circumscribed margins, posterior acoustic features, and vascularity are strongly correlated in predicting the molecular subtypes of breast cancer, and thus may further expand the role of conventional breast imaging.

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 (ΔIS 3000 -ΔIS Aba125 -IS 5 - bla NDM–5 - ble - trpF - dsbC -IS 26 ). 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.

To investigate the occurrence and genetic characteristics of the bla IMP-26-positive plasmid from a multidrug-resistant clinical isolate, Enterobacter hormaechei L51. Methods: Species identification was determined by MALDI-TOF MS and Sanger sequencing. Antimicrobial susceptibility testing was performed by the agar dilution and broth microdilution. Whole-genome sequencing was conducted using Illumina HiSeq 4000-PE150 and PacBio Sequel platforms, and the genome was annotated by the RAST annotation server. The ANI analysis of genomes was performed using OAT. Phylogenetic reconstruction and analyses were performed using the Harvest suite based on the core-genome SNPs of 61 publicly available E. hormaechei genomes. Results: The E. hormaechei L51 genome consists of a 5,018,729 bp circular chromosome and a 343,918 bp conjugative IncHI2/2A plasmid pEHZJ1 encoding bla IMP-26 which surrounding genetic context was intI1-bla IMP-26-ltrA-qacEΔ1-sul1. A new sequence type (ST1103) was assigned for the isolate L51 which was resistant to cephalosporins, carbapenems, but sensitive to piperacillin-tazobactam, amikacin, tigecycline, trimethoprimsulfamethoxazole and colistin. Phylogenetic analysis demonstrated that E. hormaechei L51 belonged to the same subspecies as the reference strain E. hormaechei SCEH020042, however 18,248 divergent SNP were identified. Resistance genes in pEHZJ1 including aac (3)-IIc, aac(6ʹ)-IIc, bla SHV-178 , bla DHA-1 , bla TEM-1 , bla IMP-26 , ereA2, catII, fosA5, qnrB4, tet(D), sul1 and dfrA19. Conclusion: In our study, we identified a conjugative IncHI2/2A plasmid carrying bla IMP-26 and bla SHV-178 in E. hormaechei ST1103, a novel multidrug-resistant strain isolated from China, and describe the underlying resistance mechanisms of the strain and detailed genetic context of mega plasmid pEHZJ1.

Background The emergence of the plasmid-borne colistin-resistant gene ( mcr-1 ) poses a great threat to human health. What is worse, the recent observations of the coexistence of mcr-1 with carbapenemase encoding genes in some bacteria caused even more concern. Yet, there is a lack of observations of such strains in the human gut. Methods The isolation of E. coli L889 was performed on selective medium plates. Antibiotic susceptibilities were determined by an agar dilution and a broth microdilution method. Multi-locus sequence typing (MLST) and acquired resistance genes were also characterized. Transferability of bla NDM-9 / mcr-1 -carrying plasmids was determined by conjugation, replicon typing and S1-Pulsed-field gel electrophoresis (S1-PFGE), and Southern blotting. The sequences of these plasmids were analyzed by using whole-genome sequencing with Illumina Novaseq and Nanopore platforms. Results E. coli L889 was identified as ST1101 concomitantly carrying bla NDM-9 and mcr-1 from a stool sample. Antimicrobial susceptibility tests showed that it was resistant to various antimicrobial agents and only susceptible to tigecycline. Notably, bla NDM-9 was located on a ~114-kb untypable plasmid, while mcr-1 was located on a ~63-kb IncI2 plasmid. Conclusion Our research, to our knowledge, first reported an ST1101 E. coli strain with an untypeable bla NDM-9 -harbouring plasmid and an IncI2 mcr-1 -carrying plasmid. The colonized E. coli strains potentially contribute to the dissemination and transfer of bla NDM-9 and mcr-1 to clinical isolates, which is a considerable threat to public health and should be closely monitored.

BackgroundThe decrease of IL-2 level is believed to play an important role in the disease occurrence and development of SLE, but the relevant mechanisms have not been fully clarified. Many studies have found that the level of soluble interleukin 2 receptor α (sIL-2Rα) in SLE patients is significantly increased. Considering the fact that sIL-2Rα has the ability to bind IL-2, we want to know whether the increased sIL-2Rα has some impact on the level and function of IL-2 in SLE patients.MethodsNew onset SLE patients, treated SLE patients and healthy volunteers were recruited. The levels of serum IL-2, IL-2 mRNA in CD3+ T cells and serum sIL-2Rα were detected and compared in these subjects. Two mixed solid-phase sandwich ELISA system were designed to measure exclusively the heterodimers complex of sIL-2Rα/IL-2. The sera from SLE patients were pretreated with or without immune complex dissociation solution and detected for IL-2 levels. IL-2 standard or serum from HCs were used to co-incubate with recombinant sIL-2Rα or serum samples with high levels of sIL-2Rα and detected for IL-2 levels by ELISA. The inhibitory effect of sIL-2Rα on IL-2 biological activity was investigated by CTLL-2 cell proliferation assay. The frequencies and absolute counts of Treg cells were detected by flow cytometry before and after the addition of recombinant sIL-2Rα.ResultsThe levels of serum IL-2 in SLE patients were significantly decreased and negatively correlated with SLEDAI. However, there was no significant difference in IL-2 mRNA levels in CD3+ T cells between SLE patients and healthy controls. The levels of serum sIL-2Rα in SLE patients were significantly increased, positively correlated with the SLEDAI and negatively correlated with the levels of serum IL-2. sIL-2Rα was shown to bind to IL-2 to form immune complex, resulting in false reduction in the detection level of serum IL-2 and significant decrease in biological activity of IL-2. The increase of sIL-2Rα was demonstrated to be one of the important mechanisms for the obstruction of Treg cells differentiation in SLE patients.ConclusionIncreased serum sIL-2Rα can bind to IL-2, leading to obstruction of IL-2 activity and Treg cells differentiation.

Plasmids were isolated from E colicinogenic strains and transformed into prototrophic Escherichia coli K 12 strain DB364. Screening of E colicinogenic transformants for growth on defined medium revealed an apparent amino acid auxotrophy mediated by E4 and, to a lesser extent, E7 colicin plasmids. The auxotrophy was further investigated in E4 colicinogenic strains. From such auxotrophic transformants, denoted Pmi+ (plasmid-mediated inhibition of growth), Pmi-variants were obtained at a frequency of 3 x per bacterium. Plasmid loss was not detected among Pmi-clones. Isolation of E4 colicin plasmids from Pmi-clones and retransformation of strain DB364 with these plasmids showed that 40% of the plasmids were unable to inhibit growth of DB364 and were inferred to have alterations in an E4 colicin plasmid gene termed p i . All such plasmids were indistinguishable from native E4 colicin plasmids, with respect to colicin immunity, colicin production and excretion, and sensitivity to lysis by mitomycin C. Experiments examining the nutritional basis of the plasmid-mediated auxotrophy indicated that at least seven amino acids, isoleucine, leucine, valine, arginine, methionine, serine and glycine, were involved in the auxotrophy. However, supplementation with only these seven amino acids did not completely restore growth. Assays of the activities of enzymes involved in amino acid biosynthesis in colicinogenic and non-colicinogenic strains under repressing and derepressing growth conditions suggested that E4 colicin plasmids did not repress synthesis of the implicated amino acids. I N T R O D U C T I O NThe E colicins are highly specific bactericidal proteins which are classified by their reduced activity against a class of Escherichia coli mutants lacking the outer membrane protein which acts as the receptor for vitamin B12, E colicins and phage BF23 (Di Masi et al., 1973;Davies & Reeves, 1975). The E colicins, represented by immunity types El, E2 and E3, have been extensively studied. Several additional E colicins have been described : colicins E4, E5, E6 and E7 by Horhk (1975) and Males & Stocker (1980, and most recently colicins E8 and E9 (Cooper & James, 1984). Through tests of serological cross-reactivity amongst E colicins, assays of shared colicin receptor activity, and recombination between different E colicin plasmids and E3 colicin plasmids having N-terminal colicin mutations to restore colicinogeny, Mock & Pugsley (1982) suggested that considerable homology exists amongst the E colicins, and that their plasmid determinants share a common evolutionary origin. This view is supported by observed similarities in bactericidal activities for colicins E2 and E7, and those of colicins E3 through E6, as well as by the shared sequence homology and similarities in patterns of maxicellderived proteins encoded by E colicin plasmids (D. P. Brunner & E. A. Galella, unpublished data).

BackgroundT-SPOT.TB (T-SPOT) is widely used for the detection of Mycobacterium tuberculosis infection by detecting interferon-gamma (IFN-γ) release in T lymphocytes. This assay is performed on peripheral blood mononuclear cells (PBMCs) separated by Ficoll density gradient centrifugation, which often contain some residual platelets. Here, we investigated the impact of platelets on T-SPOT assay and related mechanisms.MethodsThe correlation between platelet count, platelet-to-lymphocyte ratio (PLR), and the IFN-γ secreting T cells (ISCs) in positive control wells of T-SPOT assay were retrospectively analyzed. T-SPOT assay was performed with un-treated PBMCs, platelets-removed PBMCs, and platelets-enriched PBMCs to confirm the impact of platelets on T-SPOT assay. The activation of platelets and their impact on IFN-γ production in T cells were detected by flow cytometry (FCM). Platelets and T cells were cultured in a mixed culture system and co-culture system respectively, followed by detection of the frequencies of IFN-γ-producing T cells and the levels of intracellular IFN-γ in T cells by FCM. Moreover, the effect of platelet releasate on the T-SPOT assay was evaluated.ResultsThe ISCs in positive control wells of the T-SPOT assay showed a significant decrease with the increase in platelet count. The PLR of the peripheral blood were negatively correlated with the ISCs in positive control wells of the T-SPOT assay. Removal or enrichment of platelets significantly increased or decreased the ISCs and the positive rate of T-SPOT. Inhibition of platelet activation significantly increased the ISCs of T-SPOT. The frequencies of IFN-γ-producing T cells in PBMCs and the levels of intracellular IFN-γ were significantly reduced by the addition of platelets, both in the mixed culture system and the co-culture system. Platelet releasate upon thrombin activation significantly decreased the ISCs of T-SPOT.ConclusionsPlatelets correlate with negative T-SPOT results by inhibiting IFN-γ production in T cells via degranulation.