Clonal spread of blaNDM-1-carrying Salmonella enterica serovar Typhimurium clone ST34 and wide spread of IncHI2/ST3-blaNDM-5 plasmid in China.

OBJECTIVES: To characterize blaNDM-carrying Salmonella recovered from a pig slaughterhouse. METHODS: In this study, 46 environment samples were collected from a slaughterhouse in China, and screened for carbapenem-resistant Enterobacterales. WGS, antimicrobial susceptibility testing and conjugation experiments were carried out to identify the isolates' resistance phenotypes and genetic characteristics. The phylogenetic relatedness of the Salmonella isolates obtained in this study and Salmonella (ST34 and ST29) in GenBank was determined. RESULTS: Two ST34 Salmonella Typhimurium and one ST29 Salmonella Stanley, recovered from three environmental samples (6.52%), were positive for blaNDM-1 and blaNDM-5, respectively. The two ST34 S. Typhimurium strains exhibited a close relationship (10-36 SNPs) with two human-derived blaNDM-1-bearing isolates from China (Hong Kong and Guangxi Province) and two blaNDM-negative ST34 Salmonella strains from the UK. The blaNDM-1 genes were located on IncHI2/ST3 plasmids. The capture of blaNDM-1 by the IncHI2/ST3 plasmid seems to be due to homologous recombination mediated by circular structures, as the genetic arrangements of the blaNDM-1 gene contain two IS26 elements of the same orientation. The blaNDM-5 gene was also carried by the IncHI2/ST3 plasmid, which shares highly similar structures with other blaNDM-5-bearing IncHI2/ST3 plasmids from other sources (fish, chicken, duck, human). CONCLUSIONS: This is the first report of a blaNDM-5-carrying IncHI2/ST3 plasmid in Salmonella. The clonal spread of NDM-1-producing ST34 S. Typhimurium across human and animal-associated environments, and the widespread dissemination of epidemic blaNDM-5-carrying IncHI2/ST3 plasmids among Enterobacteriaceae in China indicate the potential of further dissemination of blaNDM among Salmonella, which poses a threat to public health.

A ProQ/FinO family protein involved in plasmid copy number control favours fitness of bacteria carrying mcr-1-bearing IncI2 plasmids.

The plasmid-encoded colistin resistance gene mcr-1 challenges the use of polymyxins and poses a threat to public health. Although IncI2-type plasmids are the most common vector for spreading the mcr-1 gene, the mechanisms by which these plasmids adapt to host bacteria and maintain resistance genes remain unclear. Herein, we investigated the regulatory mechanism for controlling the fitness cost of an IncI2 plasmid carrying mcr-1. A putative ProQ/FinO family protein encoded by the IncI2 plasmid, designated as PcnR (plasmid copy number repressor), balances the mcr-1 expression and bacteria fitness by repressing the plasmid copy number. It binds to the first stem-loop structure of the repR mRNA to repress RepA expression, which differs from any other previously reported plasmid replication control mechanism. Plasmid invasion experiments revealed that pcnR is essential for the persistence of the mcr-1-bearing IncI2 plasmid in the bacterial populations. Additionally, single-copy mcr-1 gene still exerted a fitness cost to host bacteria, and negatively affected the persistence of the IncI2 plasmid in competitive co-cultures. These findings demonstrate that maintaining mcr-1 plasmid at a single copy is essential for its persistence, and explain the significantly reduced prevalence of mcr-1 following the ban of colistin as a growth promoter in China.

Clinical study on the effect of Bi-level positive airway pressure therapy on COPD complicated with Anxiety and Depression.

Objectives: To investigate the effect of bi-level positive airway pressure (BIPAP) therapy on chronic obstructive pulmonary disease (COPD) complicated with anxiety and depression. Methods: This is a retrospective study. One hundred patients with COPD complicated with anxiety and depression who were admitted to the Respiratory Department of The First Affiliated Hospital of Hebei North University from August 2021 to August 2022 were selected and randomly divided into two groups. Patients in the control group were given conventional symptomatic treatment, while those in the observation group were given BIPAP therapy in addition to the treatment in the control group. The two groups were compared and analyzed in terms of respiratory function indicators, the changes in the scores of St. George's Hospital Respiratory Questionnaire (SGRQ) and COPD assessment test (CAT), blood gas analysis indicators, the levels of serum neurokinin A (NKA), serum interleukin-6 (IL-6), and serum serotonin (5-HT), as well as the changes in the scores of Hamilton Anxiety Scale (HAMA) and Hamilton Depression Scale (HAMD). Results: After treatment, the levels of lung function indicators in both groups increased, SGRQ and CAT scores decreased, and pH levels remained unchanged. In addition, PaO2 levels increased, PCO2, 5-HT, NKA and IL-6 levels decreased, and HAMA and HAMD scores decreased. The improvement degree of each indicator in the observation group was superior to that in the control group. Conclusion: In the clinical treatment of COPD complicated with anxiety and depression, BIPAP boasts effective amelioration of lung function and relief of anxiety and depression symptoms, and its mechanism of action may have a close bearing on ameliorating the levels of 5-HT, NKA, and IL-6 in patients.

Decreased cyclic-AMP caused by ATP contributes to fosfomycin heteroresistance in avian Escherichia coli.

BACKGROUND: Fosfomycin is an important broad-spectrum bactericidal antibiotic to treat multidrug-resistant bacteria infections. It is generally accepted that heteroresistant bacteria are an intermediate stage in the formation of drug resistance, but there are few studies on the formation mechanism underlying fosfomycin heteroresistance (FHR). OBJECTIVES: To reveal the characteristics and formation mechanisms of FHR in Escherichia coli isolates obtained from chickens. METHODS: We identified the FHR according to the population analysis profile (PAP) test and in vitro time-kill assay. Growth curves for FHR E. coli and their subpopulations were measured. Also, the subpopulations were repeatedly cultured in fosfomycin-free medium for 5-20 overnight incubation periods. The formation mechanisms of FHR in E. coli isolates were identified through accumulation assay, carbohydrate utilization testing, real-time relative quantitative PCR analysis, DNA sequencing, transcriptomic analysis, intracellular ATP and cAMP-level assessment. RESULTS: Four of six E. coli strains were confirmed to show FHR, with a total of six subpopulations. The subpopulations restored phenotypic susceptibilities to fosfomycin within 5-20 overnight incubation sessions, but four of six subpopulations still maintained FHR characteristics. Differing from their parental isolates, the uptake of fosfomycin in the subpopulations through GlpT was reduced remarkably. Further studies identified that the low expression of glpT was due to the decrease of intracellular cAMP levels in the subpopulations, which was caused by the decreased ATP levels in cells. CONCLUSIONS: Our findings revealed the formation mechanism of E. coli isolates showing FHR obtained from chicken in China and characterized the dynamic change traits in vitro of the subpopulations.

Cucurbitacin B regulates lung cancer cell proliferation and apoptosis via inhibiting the IL-6/STAT3 pathway through the lncRNA XIST/miR-let-7c axis.

CONTEXT: Lung cancer, the most common type of cancer, has a high mortality rate. Cucurbitacin B (CuB), a natural compound extracted from Cucurbitaceae plants, has antitumor effects. OBJECTIVE: We investigated the role of CuB on lung cancer and its potential mechanisms. MATERIALS AND METHODS: A549 cells were treated with 0.1, 0.3, 0.6, and 0.9 µM CuB for 12, 24, and 48 h or untreated. Gene and protein levels were evaluated by quantitative real-time polymerase chain reaction (qRT-PCR) and western blotting. Enzyme-linked immunosorbent assay (ELISA) detected inflammatory factors levels (TNF-α and IL-10). 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), flow cytometry, and colony formation assays measured cell viability, apoptosis, and proliferation. The interaction between miR-let-7c and long non-coding RNA X inactive-specific transcript (XIST) or interleukin-6 (IL-6) was verified by dual-luciferase reporter assays. RESULTS: CuB treatment inhibited the proliferation of lung cancer cells and promoted cell apoptosis, and increased the expression of Bax and cleaved caspase3, decreased cyclin B1 and Bcl-2 expression. CuB suppressed XIST and IL-6 expression, and enhanced miR-let-7c expression. XIST silencing enhanced the inhibitory effect of CuB on cell proliferation and the promotion effect on apoptosis via upregulating miR-let-7c. Moreover, XIST targeted miR-let-7c to activate the IL-6/STAT axis. MiR-let-7c overexpression enhanced the regulatory effect of CuB on proliferation and apoptosis via suppressing the IL-6/STAT3 pathway. DISCUSSION AND CONCLUSION: CuB regulated cell proliferation and apoptosis by inhibiting the XIST/miR-let-7c/IL-6/STAT3 axis in lung cancer. These findings indicate CuB may have the possibility of clinical application in lung cancer treatment.

[Clinical and gene mutation features of cystic fibrosis: an analysis of 8 cases]. / 8ä¾‹å›Šæ€§çº¤ç»´åŒ–æ‚£å„¿ä¸´åºŠåŠåŸºå› çªå˜åˆ†æž.

OBJECTIVES: To study the clinical features and gene mutation sites of children with cystic fibrosis (CF), in order to improve the understanding of CF to reduce misdiagnosis and missed diagnosis. METHODS: A retrospective analysis was performed on the medical records of 8 children with CF who were diagnosed in Hebei Children's Hospital from 2018 to 2021. RESULTS: Among the 8 children with CF, there were 5 boys and 3 girls, with an age of 3-48 months (median 8 months) at diagnosis, and the age of onset ranged from 0 to 24 months (median 2.5 months). Clinical manifestations included recurrent respiratory infection in 7 children, sinusitis in 3 children, bronchiectasis in 4 children, diarrhea in 8 children, fatty diarrhea in 3 children, suspected pancreatic insufficiency in 6 children, pancreatic cystic fibrosis in 1 child, malnutrition in 5 children, and pseudo-Bartter syndrome in 4 children. The most common respiratory pathogens were Pseudomonas aeruginosa (4 children). A total of 16 mutation sites were identified by high-throughput sequencing, multiplex ligation-dependent probe amplification, and Sanger sequencing, including 5 frameshift mutations, 4 nonsense mutations, 4 missense mutations, 2 exon deletions, and 1 splice mutation. CFTR mutations were found in all 8 children. p.G970D was the most common mutation (3 children), and F508del mutation was observed in one child. Four novel mutations were noted: deletion exon15, c.3796_3797dupGA(p.I1267Kfs*12), c.2328dupA(p.V777Sfs*2), and c.2950G>A(p.D984N). CONCLUSIONS: p.G970D is the most common mutation type in children with CF. CF should be considered for children who have recurrent respiratory infection or test positive for Pseudomonas aeruginosa, with or without digestive manifestations or pseudo-Bartter syndrome.

A Novel Transferable Resistance-Nodulation-Division Pump Gene Cluster, tmexCD2-toprJ2, Confers Tigecycline Resistance in Raoultella ornithinolytica.

We recently identified a novel plasmid-mediated resistance-nodulation-division (RND)-type efflux pump gene cluster, tmexCD1-toprJ1, in Klebsiella pneumoniae that conferred resistance to multiple antimicrobials, including tigecycline. While homologs of tmexCD1-toprJ1 were found encoded in many other bacterial species in GenBank, their functions and transfer mechanisms remain unknown. This study identified another mobile gene cluster, tmexCD2-toprJ2, co-occurring on both a plasmid (pHNNC189-2) and the chromosome of a clinical Raoultella ornithinolytica isolate, strain NC189, producing KPC-2, NDM-1, and RmtC. tmexCD2-toprJ2 shares high similarity at the nucleotide level with tmexCD1-toprJ1, with 98.02%, 96.75%, and 99.93% identities to tmexC1, tmexD1, and toprJ1, respectively. Phylogenetic analysis revealed that tmexCD2-toprJ2 may have originated from the chromosome of a Pseudomonas species. The expression of tmexCD2-toprJ2 in an Escherichia coli strain resulted in an 8-fold increase in the tigecycline MIC and decreased susceptibility to other antimicrobials. Genetic context analyses demonstrated that tmexCD2-toprJ2, together with the adjacent hypothetical site-specific integrase genes, was possibly captured and mobilized by a XerD-like tyrosine recombinase system, forming a putative transposition unit (xerD-like-int3-like-thf2-ybjD-umuD-ΔumuC1-int1-like-int2-like-hp1-hp2-tnfxB2-ISBvi2-tmexCD2-toprJ2-ΔumuC1), which was inserted into umuC-like genes in both the NC189 plasmid pHNNC189-2 and the chromosome. Since tmexCD1-toprJ1 and tmexCD2-toprJ2 could confer multidrug resistance, the spread of these gene clusters, associated with the new recombinase system, calls for more attention.

Novel tigecycline resistance gene cluster tnfxB3-tmexCD3-toprJ1b in Proteus spp. and Pseudomonas aeruginosa, co-existing with tet(X6) on an SXT/R391 integrative and conjugative element.

OBJECTIVES: To characterize a novel MDR efflux pump gene cluster tnfxB3-tmexCD3-toprJ1b carried by Proteus spp. and Pseudomonas aeruginosa strains from chickens. METHODS: Antimicrobial susceptibility testing, conjugation and WGS were performed to characterize tnfxB3-tmexCD3-toprJ1b-positive isolates. Cloning and reverse transcription-quantitative PCR were performed to investigate the function of tnfxB3-tmexCD3-toprJ1b. RESULTS: The WGS data revealed that a novel efflux pump gene cluster, tnfxB3-tmexCD3-toprJ1b, was identified on the chromosome of the Proteus cibarius strain SDQ8C180-2T, where an SXT/R391-family integrative and conjugative element (ICE) was found to co-carry tet(X6) and tnfxB3-tmexCD3-toprJ1b. Further retrospective analysis found two other tnfxB3-tmexCD3-toprJ1b variants in a Proteus mirabilis isolate and a P. aeruginosa isolate, respectively. tmexCD3-toprJ1b and its variants increased the MICs of tigecycline (8-fold) and other antibiotics (2-8-fold) in Escherichia coli host strains. The TNfxB3 protein down-regulated the expression of the tmexCD3-toprJ1b operon. Moreover, genetic-context analyses showed that tnfxB3-tmexCD3-toprJ1b together with adjacent integrase genes appeared to compose a transferable module 'int1-like+int2-like+hp1+hp2+ISCfr1+tnfxB3-tmexCD3-toprJ1b', which was inserted into the umuC-like gene of this ICE. Further analysis of the tnfxB3-tmexCD3-toprJ1b-harbouring sequences deposited in GenBank revealed similar transferable modules inserted into umuC-like genes in plasmids or chromosomes of Klebsiella pneumoniae, Pseudomonas spp. and Aeromonas spp., implying that these modules could be transferred across different bacterial species. CONCLUSIONS: To the best of our knowledge, this is the first identification of a novel tigecycline gene cluster, tmexCD3-toprJ1b, which co-exists with tet(X6) within an ICE. More attention should be paid to the co-transfer of these two tigecycline resistance determinants via an ICE to other Gram-negative bacteria.

Double deletion of cpxR and tolC significantly increases the susceptibility of Salmonella enterica serovar Typhimurium to colistin.

BACKGROUND: The increasing use of colistin causes a serious breach in our last line of defence against MDR Gram-negative pathogens. Our previous study showed that CpxR overexpression increases the susceptibility of acrB and cpxR double-deleted Salmonella enterica serovar Typhimurium to colistin. OBJECTIVES: To identify the mechanism of CpxAR and efflux pumps that synergistically enhance the susceptibility of S. Typhimurium to colistin. METHODS: A series of cpxR- and tolC-deleted mutants and a cpxR-complemented strain from a multidrug-susceptible standard strain of S. Typhimurium (JS) were generated in our previous study. Herein, we investigated the susceptibility of these strains to colistin through the broth microdilution method, time-kill curves and survival assays. Growth curves were measured by OD600 in LB broth, tryptone-soy broth (TSB) and M9-glucose (0.2%) minimal media. Finally, molecular mechanisms underlying the mode of action were elucidated by transcriptomic analysis. RESULTS: We found that in contrast to JS (0.8 mg/L), the MIC of colistin for JSΔtolC::kan showed a 16-fold decrease (0.05 mg/L). Notably, JSΔcpxRΔtolC and JSΔcpxRΔtolC/pcpxR were associated with a 256-fold decrease (0.0031 mg/L) compared with JS. Growth curves identified that JSΔcpxRΔtolC and JSΔcpxRΔtolC/pcpxR displayed a markedly lower growth rate and poorer adaptability. In addition, time-kill curves and survival assays showed that JSΔcpxRΔtolC and JSΔcpxRΔtolC/pcpxR were more susceptible to colistin. Lastly, double deletion of cpxR and tolC enhanced oxidative damage through promoting oxidative phosphorylation, the tricarboxylic acid (TCA) cycle and trimethylamine N-oxide (TMAO) respiration. CONCLUSIONS: Our findings revealed that double deletion of cpxR and tolC significantly increases the susceptibility of S. Typhimurium to colistin.

Characterization of blaCMY-2-carrying IncC and rmtB-carrying IncI1/ST136 plasmids in an avian Escherichia coli ST224 strain.

To analyze characteristics and underlying evolutionary processes of IncC and IncI1 plasmids in a multidrug-resistant avian E. coli strain, antibiotic susceptibility testing, PCR, conjugation assays, and next-generation sequencing were performed. The type 1 IncC plasmid pEC009.1 harbored three antimicrobial resistance regions including ISEcp1-blaCMY-2-blc-sugE, ARI-B resistance island, and ARI-A island that was a mosaic multidrug resistance region (MRR) comprised of a class 1 integron with cassette array |aac(6')-II(aacA7)|qacE∆1|sul1|, IS26-mphR(A)-mrx-mph(A)-IS26, IS26-fosA3-IS26, and mercury resistance cluster merRTPABDE. It is the first report of three different size circular forms derived from IS26-mphR(A)-mrx-mph(A)-IS26-fosA3-IS26 in ARI-A of type 1 IncC plasmid. In IncI1/ST136 pEC009.2, the truncated transposon Tn1722 carrying blaTEM-1b, rmtB, aac(3)-IId(aacC2d), and a class 1 integron with cassette array |dfrA12|orfF|aadA2|, inserted into the plasmid backbone generating 5-bp direct repeats (DRs, TATAA) at the boundaries of the region, which was highly similar to that of other IncI1 plasmids, and differed by the arrangements of resistance determinants. Comparison among two epidemic plasmid lineages showed complex MRRs respectively located in the specific position in type 1 IncC and IncI1/ST136 plasmids with conserved backbones, and these have evolved via multiple events involved in mobile elements-mediated loss and gain of resistance genes and accessory genes. Strains harboring these plasmids may serve as a reservoir for antibiotic resistance genes, thereby contributing to the rapid spread of resistance genes and posing a public health threat.

LncRNA XIST knockdown alleviates LPS-induced acute lung injury by inactivation of XIST/miR-132-3p/MAPK14 pathway : XIST promotes ALI via miR-132-3p/MAPK14 axis.

Acute lung injury (ALI) is a fatal inflammatory response syndrome. LncRNA XIST (XIST) is a lung cancer-related gene and participates in pneumonia. However, whether XIST participates in lipopolysaccharides (LPS)-induced ALI remains unclear. LPS-induced inflammation model was constructed in vitro, then cell viability, cytokines, cell apoptosis, protein, and mRNA expressions were individually detected by cell counting kit-8, enzyme-linked immunosorbent assay and flow cytometry, Western blot, and qRT-PCR. A dual-luciferase reporter assay confirmed the relationships among XIST, miR-132-3p, and MAPK14. Furthermore, inflammation and conditions after knockdown of XIST were assessed by hematoxylin and eosin staining, lung wet-to-dry weight ratio, PaO2/FiO2 ratio, and malondialdehyde (MDA) contents using LPS-induced in vivo model. Our findings indicated that the LPS challenge decreased cell viability, increased cell apoptosis, and caused secretions of pro-inflammatory cytokines. Noticeably, LPS significantly upregulated XIST, MAPK14, and downregulated miR-132-3p. Mechanistically, XIST acted as a molecular sponge to suppress miR-132-3p, and MAPK14 was identified as a target of miR-132-3p. Functional analyses demonstrated that XIST silencing remarkably increased cell survival and alleviated cell death and lung injury through decreasing TNF-α, IL-1ß, IL-6, accumulation of inflammatory cells, alveolar hemorrhage, MDA release, and increased PaO2/FiO2 ratio, as well as upregulating Bcl-2, and downregulating Bax, MAPK14, and p-extracellular signal-regulated kinases ½. In contrast, inhibition of the miR-132-3p antagonized the effects of XIST silencing. In conclusion, inhibition of XIST exhibited a protective role in LPS-induced ALI through modulating the miR-132-3p/MAPK14 axis.

The effect of gemcitabine combined with AMD3100 applying to cholangiocarcinoma RBE cell lines to CXCR4/CXCL12 axis.

PURPOSE: To evaluate the effect of AMD3100 treatment to cholangiocarcinoma by analyzing the relationship between them, and provide experimental evidence for whether AMD3100 can become a clinical treatment drug for cholangiocarcinoma. MATERIALS AND METHODS: Cholangiocarcinoma RBE cell lines were used in this study. MTT cell proliferation test was used for evaluating the effect of gemcitabine and AMD3100 to cell. CXCR4, N-cadherin, VEGF-C and MMP-9 were detect by RT-PCR and western. Transwell was used for evaluating the invasion effect. RESULTS: We demonstrated that as the concentration of gemcitabine increasing from 0.33, 3.33 to 33.33 uM, the cell survival rate was 76.65%, 71.40%, 52.25%, respectively. RT-PCR and Western blot that gemcitabine could affect the expression of CXCR4 protein and the level of mRNA transcription in a dose-dependent manner. N-cadherin VEGF-C, MMP-9 mRNA transcription level showed a significant upward trend in gemcitabine group. In Transwell test, the number of cells in the gemcitabine group was significantly higher than that in the no-medication group (p < .05), the AMD3100 group and the combination group of gemcitabine and AMD3100, the difference between the no-medication group and the AMD3100 monotherapy group was not significant, and the combination group was between them. CONCLUSIONS: This study showed that gemcitabine significantly inhibited the growth of cholangiocarcinoma RBE cells in a dose-dependent manner, and gemcitabine can affect the expression of CXCR4, N-cadherin, VEGF-C, MMP-9 protein and mRNA. Cell invasion and metastasis-related factors decreased after AMD3100 combined with gemcitabine.

The MyD88 inhibitor TJ-M2010-2 suppresses proliferation, migration and invasion of breast cancer cells by regulating MyD88/GSK-3ß and MyD88/NF-κB signalling pathways.

MyD88 has been implicated in the tumourigenesis, metastasis and recurrence of breast cancer (BC). Here we utilized TJ-M2010-2 (TJ), an inhibitor of MyD88 homodimerimerization, and siMyD88 to suppress the function of MyD88 in MCF-7 and MDA-MB-231 cells. BC cells were treated in vitro and xenografted into nude mice to generate a model in vivo. TJ inhibited BC cell growth by impeding proliferation rather than by promoting apoptosis in vitro. Additionally, TJ and siMyD88 significantly attenuated cell migration and invasion, inhibited EMT-like progression and reduced cytokine (IL-6, IL-8, TGF-ß1 and TNF-α) secretion induced by LPS. In vivo, TJ significantly hindered tumour growth in mice. Notably, TJ also decreased the secretion of IL-6, IL-8, TGF-ß1, and TNF-α and M2 macrophage infiltration in the tumour microenvironment. The expression of MyD88, TRAF6, NF-κB p65, Snail, MMP-2, MMP-9, p-GSK-3ß and p-Akt was significantly downregulated by TJ in BC cells and tumour tissues. Collectively, these results suggest that a MyD88 inhibitor (TJ) may be a promising therapeutic modality for treating BC patients.

[Epidemiological features of severe acute respiratory syndrome coronavirus 2 infection in children in Shijiazhuang, China: an analysis of 133 cases].

OBJECTIVE: To study the epidemiological features of children with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in Shijiazhuang, China. METHODS: Based on the information officially announced on the official website of the Health Commission of Hebei Province, epidemiological data were collected from 133 children, aged 0-18 years, who were diagnosed with SARS-CoV-2 infection in Shijiazhuang from January 2 to January 30, 2021. A statistical analysis was performed for general status, regional distribution, presence or absence of clusters, and results of SARS-CoV-2 nucleic acid tests. RESULTS: Among the 133 children with SARS-CoV-2 infection, there were 65 boys and 68 girls, with a male/female ratio of 0.96:1. The youngest age of onset was 3 months and 7 days, and the mean age of onset was (9±5) years. Of all the 133 children, 90(67.7%) were the first confirmed case of SARS-CoV-2 infection among their family members. Of all the children, 108(81.2%) came from the Gaocheng District in Shijiazhuang, among whom 38(28.6%) were from Xiaoguozhuang Village where the first patient with a confirmed diagnosis lived. SARS-CoV-2 nucleic acid test at week 2 after the outbreak showed positive results in 88 children (66.2%), and only 5 children had clinical symptoms before positive SARS-CoV-2 results were obtained. Of all the 133 children, 19(14.3%) were found positive in the first SARS-CoV-2 nucleic acid test after the outbreak, and 70(52.6%) had positive results for ≥4 times. There were 98 school students with infection, among whom 74(75.5%) were the first confirmed case in their family, and among 35 non-school students, 16(45.7%) were the first confirmed case in their family (P < 0.05). CONCLUSIONS: Among the children confirmed with SARS-CoV-2 infection in Shijiazhuang, there is a high proportion of children who are the first confirmed case in their family, and the children are mainly distributed in the rural areas of Gaocheng. Most of these children are students, so the prevention and control of cluster infection in schools should be taken seriously. There are often no symptoms before SARS-CoV-2 nucleic acid test, with a low positive rate of the first nucleic acid test, which increases the difficulty of early discovery of the epidemic.

Intraductal Therapy in Breast Cancer: Current Status and Future Prospective.

With our improved understanding of the biological behavior of breast cancer, minimally invasive intervention is urgently needed for personalized treatment of early disease. Intraductal therapy is one such minimally invasive approach. With the help of appropriate tools, technologies using the intraductal means of entering the ducts may be used both to diagnose and treat lesions in the mammary duct system with less trauma and at the same time avoid systemic toxicity. Traditional agents such as those targeting pathways, endocrine therapy, immunotherapy, or gene therapy can be used alone or combined with other new technologies, such as nanomaterials, through the intraductal route. Additionally, relevant mammary tumor models in rodents which reflect changes in the tumor microenvironment will help deepen our understanding of their biological behavior and heterogeneity. This article reviews the current status and future prospects of intraductal therapy in breast cancer, with emphasis on ductal carcinoma in situ.

CpxR regulates the colistin susceptibility of Salmonella Typhimurium by a multitarget mechanism.

BACKGROUND: The two-component signalling systems PmrAB and PhoPQ of Salmonella have been extensively studied with regard to colistin resistance. We previously showed that overexpressed CpxR could significantly increase the colistin susceptibility (16-fold compared with the WT strain) of Salmonella enterica serovar Typhimurium (Salmonella Typhimurium) through PmrAB and PhoPQ. OBJECTIVES: To identify the potential target genes of CpxR in PmrAB- and PhoPQ-related signalling pathways. METHODS: His6-CpxR was prokaryotically expressed and purified by Ni-NTA resin affinity chromatography. ß-Galactosidase activity assays were conducted to investigate whether CpxR could regulate the promoters of colistin resistance-related genes (CRRGs). Electrophoretic mobility shift assays (EMSAs) were used to further detect His6-CpxR complexes with promoters of CRRGs. RESULTS: We demonstrated for the first time (to the best of our knowledge) that CpxR and the AcrAB-TolC efflux pump have reciprocal effects on CRRG transcription. Additionally, CpxR could regulate the colistin susceptibility of Salmonella Typhimurium by binding directly to the promoters of phoPQ, pmrC, pmrH and pmrD at the CpxR box-like sequences or indirectly through other regulators including pmrAB and mgrB. CONCLUSIONS: CpxR could regulate the colistin susceptibility of Salmonella Typhimurium by a multitarget mechanism.

Dihydroquercetin attenuates lipopolysaccharide-induced acute lung injury through modulating FOXO3-mediated NF-κB signaling via miR-132-3p.

BACKGROUND: Dihydroquercetin (DHQ) is a potent flavonoid which has been demonstrated to have multiple biological activities including anti-inflammation activity, antioxidant activity as well as anti-cancer activity etc. Recently, many studies have focused on the antioxidant activity of DHQ. However, the use of the anti-inflammation activity of DHQ in acute lung injury (ALI) has not been reported. METHODS: Cell viability was examined by CCK-8 assay. The relative expression of miR-132-3p, FOXO3 were detected by qPCR. The levels of TNF-α, IL-6 and IL-1ß were detected using enzyme-linked immunosorbent assay. The amount of apoptosis cells was detected by flow cytometry. The protein levels of Bcl-2, Bax, p-p65 and p-IκBα were measured by western blot. RESULTS: We found that DHQ-induced the expression of miR-132-3p in LPS-induced ALI. Overexpression of miR-132-3p resulted in the inhibition of FOXO3 expression and then suppressed FOXO3-activated NF-κB pathway, attenuating LPS-induced inflammatory response and apoptosis. CONCLUSION: We demonstrated FOXO3 to be a target of miR-132-3p, and DHQ could induce the expression of miR-132-3p, relieving LPS-induced ALI via miR-132-3p/FOXO3/NF-κB axis, providing a promising therapeutic target for ALI.

Rapid Increase in Carbapenemase-Producing Enterobacteriaceae in Retail Meat Driven by the Spread of the blaNDM-5-Carrying IncX3 Plasmid in China from 2016 to 2018.

The presence and molecular characteristics of carbapenemase-producing Enterobacteriaceae (CPE) among meat products in China were investigated. A total of 110 carbapenem-resistant Enterobacteriaceae (CRE) isolates, including 94 Escherichia coli and 10 Klebsiella pneumoniae isolates, were identified from 105 of 794 (13.2%) samples. The positive rates markedly increased from 2016 (9.4%) to 2018 (22.2%). Only blaNDM genes were detected; 79.1% of blaNDM genes were carried by IncX3 plasmids. Routine monitoring of carbapenemase-producing Enterobacteriaceae in the animal food supply is highly recommended.

Exploiting the Surface-Enhanced IR Absorption Effect in the Photothermally Induced Resonance AFM-IR Technique toward Nanoscale Chemical Analysis.

The photothermally induced resonance AFM-IR technique (denoted as PTIR) is a promising and still developing analytical method that can provide nanoscale chemical and topographical information. Herein, by taking advantage of a customized PTIR system with either top-down or bottom-up incidence mode for a quantum cascade laser (QCL), we explore how the surface-enhanced IR absorption (SEIRA) effect due to the Au-coated AFM tip and/or substrate may affect the PTIR signals from 25 to 580 nm thick p-nitrobenzoic acid (PNBA) samples, as a function of sample thickness, incidence mode, laser polarization, and Au film morphology. By analysis of the νas(NO2) band intensity, it is revealed that the SEIRA effect may increase the PTIR signals by 1.5-8.3 times, with that from the Au-coated substrate being greater than that from the Au-coated tip. Nevertheless, the overall PTIR signal goes up monotonically over the entire thickness range for the top-down incidence mode, while it increases and then decreases with the sample thickness for the bottom-up incidence mode. The p-polarized laser enhances the PTIR signal more than does the s-polarized laser, especially on the Au-coated substrate. The significant loss of the PTIR signal of a PNBA sample corroborates the substantial loss of the SEIRA effect of an annealed Au film. The present work may promote the application of the SEIRA effect to the PTIR technique and provides hints for developing the PTIR technique into a more versatile analytical tool.

[An analysis of GNAS and THRA gene mutations in children with congenital hypothyroidism].

OBJECTIVE: To preliminarily investigate the relationship between stimulatory G protein α subunit (GNAS) and thyroid hormone receptor α (THRA) gene mutations and clinical phenotypes in children with congenital hypothyroidism (CH). METHODS: A total of 70 children with CH diagnosed by neonatal screening were enrolled. Their peripheral blood samples were collected to extract genomic DNA. GNAS and THRA genes were screened for mutations using next-generation sequencing. Bioinformatics software was used to analyze the pathogenicity of gene mutations. RESULTS: Of the 70 children with CH, nine missense mutations (three known mutations and six novel mutations) in the GNAS gene were detected in three patients (4%), and one gene polymorphism, c.508A>G(p.I170V), in the THRA gene was detected in four patients. The analysis results of bioinformatics software and ACMG/AMP guidelines showed that the two GNAS gene mutations [c.301C>T(p.R101C) and c.334G>A(p.E112K)] were more likely to be pathogenic. Three children with GNAS gene mutations showed different degrees of hypothyroidism. CONCLUSIONS: GNAS gene mutations are related to the development of CH, and children with CH have different clinical manifestations. THRA gene mutations may not be associated with CH.