Effects of Simulated Microgravity on Acquired Antibiotic Resistance in Klebsiella pneumoniae Exposed to Trace Antibiotic.

Objective: The purpose of this study is to gain a better understanding of the impact of microgravity on antibiotic resistance. Methods: K. pneumoniae original (KPO) strain was cultured under either simulated microgravity (SMG) conditions with background antibiotic exposure (SMGA) for the experimental strain or a normal gravity condition with background antibiotic exposure (NGA) for the control strain. The K. pneumoniae original (KPO) strain was also cultured under normal gravity (NG) as an additional control. Antibiotic susceptibility was evaluated prior to their incubation under SMGA, NGA, or NG conditions. After 20 cycles of incubation, antibiotic susceptibility, genomic, transcriptomic, and proteomic tests were conducted on them. Results: SMGA and NGA strains both showed resistance to ciprofloxacin and intermediate resistance to levofloxacin. Genes associated with antibiotic resistance of Klebsiella pneumoniae, including acrB, oqxB, oqxA, ompC, ompF, and tolC were found to be differently expressed between SMGA and NGA strains or between SMGA and NG strains. It was found that the biggest family of genes in the differently expressed gene (DEG) cluster between SMGA and NGA and between SMGA and NG was the same, paaBCDFGHI, but with opposite change direction, i.e., downregulation between SMGA and NGA strains, while upregulation between SMGA and NG strains. Besides, the top-ranking functional descriptions in terms of the number of DEGs whether between SMGA and NGA or between SMGA and NG were "amino acid transport and metabolism", "carbohydrate transport and metabolism", "transcription", and "inorganic ion transport and metabolism". Two pathways of "citrate cycle (TCA cycle)" and "oxidative phosphorylation" were significantly enriched by DEGs both between SMGA and NGA and between SMGA and NG. Conclusion: Our study confirmed that low levels of antibiotics present in SMG can select for resistant K. pneumoniae strains. However, SMG did not alter the antibiotic resistance in K. pneumoniae induced by exposure to trace antibiotic.

Effects of short-term exposure to simulated microgravity on the physiology of Bacillus subtilis and multiomic analysis.

In our study, Bacillus subtilis was disposed to a simulated microgravity (SMG) environment in high-aspect ratio rotating-wall vessel bioreactors for 14 days, while the control group was disposed to the same bioreactors in a normal gravity (NG) environment for 14 days. The B. subtilis strain exposed to the SMG (labeled BSS) showed an enhanced growth ability, increased biofilm formation ability, increased sensitivity to ampicillin sulbactam and cefotaxime, and some metabolic alterations compared with the B. subtilis strain under NG conditions (labeled BSN) and the original strain of B. subtilis (labeled BSO). The differentially expressed proteins (DEPs) associated with an increased growth rate, such as DNA strand exchange activity, oxidoreductase activity, proton-transporting ATP synthase complex, and biosynthetic process, were significantly upregulated in BSS. The enhanced biofilm formation ability may be related with the DEPs of spore germination and protein processing in BSS, and differentially expressed genes involved in protein localization and peptide secretion were also significantly enriched. The results revealed that SMG may increase the level of related functional proteins by upregulating or downregulating affiliated genes to change physiological characteristics and modulate growth ability, biofilm formation ability (epsB, epsC, epsN), antibiotic sensitivity (penP) and metabolism. Our experiment may gives new ideas for the study of space microbiology.

[Protective effects of hepatocyte growth factor on hypoxic human pulmonary microvascular endothelial cells].

OBJECTIVE: To investigate the protective effects of hepatocyte growth factor (HGF) on hypoxic human pulmonary microvascular endothelial cells (HPMECs). METHODS: HPMECs were cultured in vitro, and the hypoxic model was established by the physical method. Cells were divided into 4 groups: the control group, the hypoxic group, HGF group, and phytohemagglutinin (PHA) group. The 7(th) generation of HPMECs was evaluated by the method of immunocytochemistry. The persistence rate of HPMECs was measured by MTT assay and the adhesive cells were counted by the microscopy. The expression of intercellular adhesion molecule-1 (ICAM-1) protein was determined by immunofluorescence staining. RESULTS: The adherence percentage of cells significantly decreased after hypoxia, whereas the expression of the ICAM-1 protein was significantly higher in the hypoxia group than in control group (P<0.01). Compared with the hypoxia group, the persistence and adherence percentage of cells in the HGF group significantly increased (P<0.01), whereas the expression of the ICAM-1 protein significantly dropped (P<0.01). In the PHA group, the persistence and adhesion rate were significantly different from those in the hypoxia group and HGF group (P<0.01), and the expression of the ICAM-1 protein increased significantly (P<0.01). CONCLUSION: HGF could inhibit the hypoxic damage of HPMECs by decreasing the persistence and the adhesive capacity of these cells and inducing the expression of ICAM-1.

Draft genome sequence of Escherichia coli LCT-EC106.

Escherichia coli is a Gram-negative, rod-shaped bacterium that is commonly found in the intestine of warm-blooded organisms. Most E. coli strains are harmless, but some serotypes can cause serious food poisoning in humans. Here, we present the complete genome sequence of Escherichia coli LCT-EC106, which was isolated from CGMCC 1.2385.

A Novel Ferroptosis-Related lncRNA Signature for Prognosis Prediction in Patients with Papillary Renal Cell Carcinoma.

PURPOSE: Papillary renal cell carcinoma (PRCC) is a common renal cell carcinoma. Recent studies have reported that ferroptosis is involved in the occurrence and development of tumors. Long non-coding RNAs can be used as independent biomarkers for the diagnosis and prognosis of a variety of tumors. METHODS: Gene expression profile and clinical information of patients with PRCC were obtained from The Cancer Genome Atlas (TCGA) database. Lasso penalized Cox regression and univariate Cox regression analysis were utilized for model construction. The Kaplan-Meier (K-M) and receiver operating characteristic (ROC) curves were plotted to validate the predictive effect of the prognostic signature. Immune cell infiltration and immune function were compared between the high-risk and low-risk groups. Chemotherapy sensitivity analysis was also performed. RESULTS: We constructed a prognostic signature consisting of 15 ferroptosis-related lncRNAs. The K-M curves validated the fine predictive accuracy of the prognostic signature (p < 0.001). The area under the curve (AUC) of the lncRNA signature was 0.930, exhibiting robust prognostic capacity. The high-risk group had a greater degree of immune cell infiltration than the low-risk group. Significant differences in inflammation promotion, parainflammation, and type I IFN response were noted between the low-risk and high-risk groups (p < 0.01). The expression levels of immune checkpoints including CD80, IDO1, and LAG3 were significantly higher in the high-risk group than in the low-risk group (p < 0.05). Chemotherapy sensitivity analysis showed that MNX1-AS1, ZFAS1, MIR4435-2HG, and ADAMTS9-AS1 were significantly correlated with the sensitivity of some chemotherapy drugs (p < 0.05). CONCLUSION: We demonstrated that a ferroptosis-related lncRNA prognostic signature could be a novel biomarker for PRCC.

Clinicopathological significance and prognostic value of CD133 expression in triple-negative breast carcinoma.

Currently, CD133 is one of the best markers to characterize cancer stem cells and Her-1 is reported as an important marker for the prognosis of triple-negative breast cancer. To investigate the relationship between the expression of CD133 and Her-1 and clinicopathology as well as prognosis in triple-negative breast cancer, 67 cases of triple-negative invasive ductal breast carcinoma taken from 422 patients with breast cancer were analyzed by immunohistochemistry and clinicopathology with follow-up. The CD133 and Her-1 were expressed as positive in 43.3% (29/67) and 53.7% (36/67) of patients, respectively. The expression of CD133 corresponded to tumor size (P = 0.022), clinical stage (P = 0.001) and lymphatic metastasis (P = 0.001), but not to age and histological grade. By Kaplan-Meier analysis the expression of CD133 was correlative with overall survival (OS) (log rank = 9.346, P = 0.002) and disease free survival (DFS) (log rank = 38.840, P = 0.0001) time of breast cancer patients. The expression of Her-1 was corresponding to tumor size (P = 0.031), clinical stage (P = 0.005) and lymphatic metastasis (P = 0.002), but not to age and histological grade. By Kaplan-Meier analysis the expression of Her-1 was correlative with overall survival (OS) (log rank = 7.998, P = 0.005) and DFS (log rank = 4.227, P = 0.040) time of patients with cancer. It is concluded that the expression of CD133 and Her-1 may be correlative with prognosis in triple-negative breast cancer.

Decreased biofilm formation in Proteus mirabilis after short-term exposure to a simulated microgravity environment.

BACKGROUND: Microbes threaten human health in space exploration. Studies have shown that Proteus mirabilis has been found in human space habitats. In addition, the biological characteristics of P. mirabilis in space have been studied unconditionally. The simulated microgravity environment provides a platform for understanding the changes in the biological characteristics of P. mirabilis. OBJECTIVE: This study intends to explore the effect of simulated microgravity on P. mirabilis, the formation of P. mirabilis biofilm, and its related mechanism. METHODS: The strange deformable rods were cultured continuously for 14 days under microgravity simulated in high-aspect rotating vessels (HARVs). The morphology, growth rate, metabolism, and biofilm formation of the strain were measured, and the phenotypic changes of P. mirabilis were evaluated. Transcriptome sequencing was used to detect differentially expressed genes under simulated microgravity and compared with phenotype. RESULTS: The growth rate, metabolic ability, and biofilm forming ability of P. mirabilis were lower than those of normal gravity culture under the condition of simulated microgravity. Further analysis showed that the decrease of growth rate, metabolic ability, and biofilm forming ability may be caused by the downregulation of related genes (pstS, sodB, and fumC). CONCLUSION: The simulated microgravity condition enables us to explore the potential relationship between bacterial phenotype and molecular biology, thus opening up a suitable and constructive method for medical fields that have not been explored before. It provides a certain strategy for the treatment of P. mirabilis infectious diseases in space environment by exploring the microgravity of P. mirabilis.

Effects of Simulated Microgravity on the Physiology of Stenotrophomonas maltophilia and Multiomic Analysis.

Many studies have shown that the space environment plays a pivotal role in changing the characteristics of conditional pathogens, especially their pathogenicity and virulence. However, Stenotrophomonas maltophilia, a type of conditional pathogen that has shown to a gradual increase in clinical morbidity in recent years, has rarely been reported for its impact in space. In this study, S. maltophilia was exposed to a simulated microgravity (SMG) environment in high-aspect ratio rotating-wall vessel bioreactors for 14days, while the control group was exposed to the same bioreactors in a normal gravity (NG) environment. Then, combined phenotypic, genomic, transcriptomic, and proteomic analyses were conducted to compare the influence of the SMG and NG on S. maltophilia. The results showed that S. maltophilia in simulated microgravity displayed an increased growth rate, enhanced biofilm formation ability, increased swimming motility, and metabolic alterations compared with those of S. maltophilia in normal gravity and the original strain of S. maltophilia. Clusters of Orthologous Groups (COG) annotation analysis indicated that the increased growth rate might be related to the upregulation of differentially expressed genes (DEGs) involved in energy metabolism and conversion, secondary metabolite biosynthesis, transport and catabolism, intracellular trafficking, secretion, and vesicular transport. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses showed that the increased motility might be associated the upregulation of differentially expressed proteins (DEPs) involved in locomotion, localization, biological adhesion, and binding, in accordance with the upregulated DEGs in cell motility according to COG classification, including pilP, pilM, flgE, flgG, and ronN. Additionally, the increased biofilm formation ability might be associated with the upregulation of DEPs involved in biofilm formation, the bacterial secretion system, biological adhesion, and cell adhesion, which were shown to be regulated by the differentially expressed genes (chpB, chpC, rpoN, pilA, pilG, pilH, and pilJ) through the integration of transcriptomic and proteomic analyses. These results suggested that simulated microgravity might increase the level of corresponding functional proteins by upregulating related genes to alter physiological characteristics and modulate growth rate, motility, biofilm formation, and metabolism. In conclusion, this study is the first general analysis of the phenotypic, genomic, transcriptomic, and proteomic changes in S. maltophilia under simulated microgravity and provides some suggestions for future studies of space microbiology.

Genomic characterization of Escherichia coli LCT-EC001, an extremely multidrug-resistant strain with an amazing number of resistance genes.

BACKGROUND: Multidrug resistance is a growing global public health threat with far more serious consequences than generally anticipated. In this study, we investigated the antibiotic resistance and genomic traits of a clinical strain of Escherichia coli LCT-EC001. RESULTS: LCT-EC001 was resistant to 16 kinds of widely used antibiotics, including fourth-generation cephalosporins and carbapenems. In total, up to 68 determinants associated with antibiotic resistance were identified, including 8 beta-lactamase genes (notably producing ESBLs and KPCs), 31 multidrug efflux system genes, 6 outer membrane transport system genes, 4 aminoglycoside-modifying enzyme genes, 10 two-component regulatory system genes, and 9 other enzyme or transcriptional regulator genes, covering nearly all known drug-resistance mechanisms in E. coli. More than half of the resistance genes were located close to mobile genetic elements, such as plasmids, transposons, genomics islands, and insertion sequences. Phylogenetic analysis revealed that this strain may have evolved from E. coli K-12 but is a completely new MLST type. CONCLUSIONS: Antibiotic resistance was extremely severe in E. coli LCT-EC001, mainly due to mobile genetic elements that allowed the gain of a large quantity of resistance genes. The antibiotic resistance genes of E. coli LCT-EC001 can probably be transferred to other bacteria. To the best of our knowledge, this is the first report of a strain of E. coli which has such a large amount of antibiotic resistance genes. Apart from providing an E. coli reference genome with an extremely high multidrug-resistant background for future analyses, this work also offers a strategy for investigating the complement and characteristics of genes contributing to drug resistance at the whole-genome level.

Effects of OM-85 BV in patients with chronic obstructive pulmonary disease: A systematic review and meta-analysis.

This study aimed to identify the effects of OM-85 BV in patients with chronic obstructive pulmonary disease (COPD). PubMed, Embase, CINAHL, and ClinicalTrials.gov were searched for eligible randomized controlled trials (RCTs). The major end point was exacerbation rate, and the minor end points included duration of hospitalization, severity of acute exacerbation, incidence rate of patients using antibiotics, and adverse events. All data were derived with relative risks (RRs) and weighted mean differences. Five RCTs with 1190 patients were enrolled in the meta-analysis. OM-85 BV was associated with 20% and 39% reductions in exacerbation rate (RR, 0.80; 95% confidence interval [CIs], 0.65-0.97; P = .03) and incidence rate of patients using antibiotics (RR, 0.61; 95%CI, 0.48-0.77; P < .0001) compared with the placebo. However, OM-85 BV was not significantly associated with duration of hospitalization, severity of acute exacerbation, and total adverse events. Current evidence supporting the benefits of OM-85 BV to COPD patients is inadequate. Further larger-scale trials must be conducted to validate our findings and the efficacy of OM-85 BV in COPD patients.

[Expression of c-kit protein and its significance in human small cell lung cancer].

BACKGROUND: To investigate the clinicopathological significance of c-kit protein expression in small cell lung cancer (SCLC). METHODS: c-kit protein expression was detected in 52 formalin-fixed and paraffin-embedded SCLC, 20 non-small cell lung cancer (NSCLC) and 10 normal lung tissues by immunohistochemistry with rabbit antibody to human c-kit protein. RESULTS: c-kit protein was expressed in 61.5% (32/52) of primary SCLC, but negative in all 20 samples of NSCLC and 10 normal lung tissues. c-kit protein was localized in cytoplasm of cancer cells. The expression of c-kit protein was related to tumor size ( P =0.010) and prognosis ( P =0.000 1), but not to sex ( P =0.208), age ( P =1.000) or TNM stage ( P =0.722) of SCLC. CONCLUSIONS: c-kit protein expression may be corresponding to the prognosis of SCLC. Since in situ detection of c-kit protein is more direct than the other methods, it is helpful to clinicopathological diagnosis, targeted therapies interacting with c-kit signaling pathway and prognostic assessment in SCLC.

Genome Sequence of Bacillus cereus Strain LCT-BC235, Carried by the Shenzhou VIII Spacecraft.

In order to explore the effect of space environments on Bacillus cereus, we determined the draft genome sequence of a B. cereus strain, LCT-BC235, which was isolated after space flight.

Draft Genome Sequence of Serratia marcescens Strain LCT-SM166, a Space Flight Strain with a Specific Carbon Source Utilization Pattern.

Serratia marcescens has been detected in space habitats. To explore the influence of the space flight environment on this bacterium, we investigated the genome sequence of LCT-SM166, which was isolated after space flight and has a specific carbon source utilization pattern.

Draft Genome Sequence of Bacillus cereus LCT-BC25, Isolated from Space Flight.

Bacillus cereus strain LCT-BC25, which was carried by the Shenzhou VIII spacecraft, traveled in space for about 398 h. To investigate the response of B. cereus to space environments, we determined the genome sequence of B. cereus strain LCT-BC25, which was isolated after space flight.

Simulated microgravity alters the metastatic potential of a human lung adenocarcinoma cell line.

Simulated microgravity (SM) has been implicated in affecting diverse cellular pathways. Although there is emerging evidence that SM can alter cellular functions, its effect in cancer metastasis has not been addressed. Here, we demonstrate that SM inhibits migration, gelatinolytic activity, and cell proliferation of an A549 human lung adenocarcinoma cell line in vitro. Expression of antigen MKI67 and matrix metalloproteinase-2 (MMP2) was reduced in A549 cells stimulated by clinorotation when compared with the 1×g control condition, while overexpression of each gene improves ability of proliferation and migration, respectively, under SM conditions. These findings suggest that SM reduced the metastatic potential of human lung adenocarcinoma cells by altering the expression of MKI67 and MMP2, thereby inhibiting cell proliferation, migration, and invasion, which may provide some clues to study cancer metastasis in the future.

Draft Genome Sequences of the Enterococcus faecium Strain LCT-EF258.

The space environment has been shown to affect microbes by altering various features, including morphology, growth rate, metabolism, virulence, drug resistance, and gene expression and mutation. Here we present the draft genome sequence of the Enterococcus faecium strain LCT-EF258, derived from the E. faecium strain CGMCC 1.1736, which was exposed to 17-day space flight.