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.

Marinactinospora rubrisoli sp. nov., isolated from red soil.

A novel Marinactinospora strain JX35-4T was isolated from red soil which was collected from Wushan, northern Jiangxi Province, China. Analysis of the 16S rRNA gene sequences showed that strain JX35-4T belongs to the genus Marinactinospora and formed a distinct phylogenetic clade with Marinactinospora thermotolerans SCSIO 00652T and Marinactinospora endophytica YIM 690053T with sequence similarity of 96.97% and 96.42%, respectively. The strain was Gram-positive and formed branched substrate hyphae with no fragmentation, and abundant aerial hyphae that differentiated into long spore chains, and short rod-shaped spores. Growth occurred at 20-45 °C, pH 7.0-12.0 and in the presence of 0-7.5% (w/v) NaCl. The genomic DNA G + C content was determined to be 68.3 mol%. The cell wall of strain JX35-4T contained meso-diaminopimelic acid and xylose. Polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylcholine, phosphatidylinositol mannosides and one unidentified phospholipid. The major fatty acids of strain JX35-4T consisted of anteiso-C17:0 and iso-C16:0. Major menaquinones were MK-9(H10), MK-12 and MK-10(H2). Based on the polyphasic data, strain JX35-4T (= CGMCC 4.7382T = DSM 104977T) is concluded to represent a novel species of the genus Marinactinospora, for which the name Marinactinospora rubrisoli sp. nov. is proposed.

The theory and application of space microbiology: China's experiences in space experiments and beyond.

Microorganisms exhibit high adaptability to extreme environments of outer space via phenotypic and genetic changes. These changes may affect astronauts in the space environment as well as on Earth because mutant microbes will inevitably return with the spacecraft. However, the role and significance of these phenotypic changes and the underlying mechanisms are important unresolved questions in the field of space biology. By reviewing, especially the Chinese studies, we propose a space microbial molecular effect theory, that is, the space environment affects the nature of genes and the molecular structure of microorganisms to produce phenotypic changes. In this review, we discussed three basic theories for the research of space microbiology, including (1) space microbial pathogenicity and virulence mutations and the human mutualism theory; (2) space microbial drug-resistance mutations and metabolism associated with space pharmaceuticals theory; (3) space corrosion, microbial decontamination, and new materials technology theory.

Analysis of Long Non-Coding RNA Expression Profiles in Non-Small Cell Lung Cancer.

BACKGROUND/AIMS: Long non-coding RNAs (lncRNAs) play an important role in tumorigenesis. However, the role of lncRNA expression in human Non-small cell lung cancer (NSCLC) biology, prognosis and molecular classification remains unknown. METHODS: We established the IncRNA profile in NSCLC by re-annotation of microarrays from the Gene expression omnibus database. Quantitative real-time PCR was used to determine expression of LINC00342. RESULTS: 6066 differentially expressed IncRNAs were identified and we found a novel IncRNA, LINC00342 was significantly up-regulated in NSCLC tissues compared with normal tissues. We confirmed the over-expression of LINC00342 in a cohort of NSCLC patients and found LINC00342 expression level was positively correlated with lymph node metastasis and TNM stages. Furthermore, in a large online database of 1942 NSCLC patients, high expression of LINC00342 indicated poor Overall survival (HR = 1.28, 95% CI: 1.13-1.45) and post progression survival (HR = 1.43, 95% CI: 1.09-1.88). Bioinformatics analyses showed that LINC00342 was co-expressed with different protein-coding genes in NSCLC and normal tissues. Additionally, gene set enrichment analyses found that PTEN and P53 pathways genes were enriched in the groups with higher LINC00342 expression level. By small interfering RNAs mediated silence of LINC00342, proliferation ability was significantly inhibited in lung cancer cell line. CONCLUSION: To summary, our findings indicate that a set of IncRNAs are differentially expressed in NSCLC and we characterized a novel IncRNA, LINC00342 which is significantly up-regulated in NSCLC and could be a prognostic biomarker.

Comparative genomic analysis of Klebsiella pneumonia (LCT-KP214) and a mutant strain (LCT-KP289) obtained after spaceflight.

BACKGROUND: With the development of space science, it is important to analyze the relationship between the space environment and genome variations that might cause phenotypic changes in microbes. Klebsiella pneumoniae is commonly found on the human body and is resistant to multiple drugs. To study space-environment-induced genome variations and drug resistance changes, K. pneumoniae was carried into outer space by the Shenzhou VIII spacecraft. RESULTS: The K. pneumoniae strain LCT-KP289 was selected after spaceflight based on its phenotypic differences compared to the ground-control strain. Analysis of genomic structural variations revealed one inversion, 25 deletions, fifty-nine insertions, two translocations and six translocations with inversions. In addition, 155 and 400 unique genes were observed in LCT-KP214 and LCT-KP289, respectively, including the gene encoding dihydroxyacetone kinase, which generates the ATP and NADH required for microbial growth. Furthermore, a large number of mutant genes were related to transport and metabolism. Phylogenetic analysis revealed that most genes in these two strains had a dN/dS value greater than 1, indicating that the strain diversity increased after spaceflight. Analysis of drug-resistance phenotypes revealed that the K. pneumoniae strain LCT-KP289 was resistant to sulfamethoxazole, whereas the control strain, LCT-KP214, was not; both strains were resistant to benzylpenicillin, ampicillin, lincomycin, vancomycin, chloramphenicol and streptomycin. The sulfamethoxazole resistance may be associated with sequences in Scaffold7 in LCT-KP289, which were not observed in LCT-K214; this scaffold contained the gene sul1. In the strain LCT-KP289, we also observed a drug-resistance integron containing emrE (confers multidrug resistance) and ant (confers resistance to spectinomycin, streptomycin, tobramycin, kanamycin, sisomicin, dibekacin, and gentamicin). The gene ampC (confers resistance to penicillin, cephalosporin-ii and cephalosporin-i) was present near the integron. In addition, 30 and 26 drug-resistance genes were observed in LCT-KP289 and LCT-KP214, respectively. CONCLUSIONS: Comparison of a K. pneumoniae strain obtained after spaceflight with the ground-control strain revealed genome variations and phenotypic changes and elucidated the genomic basis of the acquired drug resistance. These data pave the way for future studies on the effects of spaceflight.

Comparison of different drug susceptibility test methods to detect rifampin heteroresistance in Mycobacterium tuberculosis.

We compared the efficiencies of different drug susceptibility testing methods in detecting rifampin (RIF) heteroresistance in Mycobacterium tuberculosis. Our data revealed that the broth dilution method found more resistance than MGIT did (P=0.046) for the low-resistance group. Similarly, the broth dilution method was more sensitive in detecting RIF heteroresistance in subpopulations with low growth rates than was MGIT (P=0.033). In conclusion, our data demonstrated that the broth dilution method was more sensitive than MGIT in detecting RIF heteroresistance.

The association of c.1471G>A genetic polymorphism in XRCC1 gene with lung cancer susceptibility in Chinese Han population.

Lung cancer is one of the most spread cancers in the world. The X-ray repair cross-complementing group 1 (XRCC1) gene plays an important role in the development of lung cancer. The objective of this study is to investigate the potential association of XRCC1 genetic polymorphisms with the susceptibility to lung cancer. In totally, 361 lung cancer patients (male, 276; female, 85; mean age, 62.55) and 361 cancer-free controls (male, 253; female, 108; mean age, 61.33) were enrolled in this case-control study. The genotypes of XRCC1 c.1471G>A genetic polymorphism were determined by the created restriction site-polymerase chain reaction (CRS-PCR) and DNA sequencing methods. The influence of XRCC1 gene on the susceptibility to lung cancer was analyzed by the analyses association. Our data indicated that significant differences were found in the frequencies of allelic and genotypic between lung cancer patients and cancer-free controls. The c.1471G>A genetic polymorphism was statistically associated with increased susceptibility to lung cancer [AA vs. GG: odds ratio (OR)=2.75, 95 % confidence interval (CI) = 1.55-4.88, P<0.001; AA vs. GA/GG: OR=2.69, 95 % CI=1.55-4.69, P<0.001; A vs. G: OR=1.37, 95 % CI=1.09-1.71, P=0.007]. The allele A and genotype AA may contribute to the susceptibility to lung cancer. Taken together, these results showed that the functional c.1471G>A genetic polymorphism of XRCC1 was associated with lung cancer susceptibility in the studied population.

TR1 promotes cell proliferation and inhibits apoptosis through cyclin A and CTGF regulation in non-small cell lung cancer.

The Hippo pathway plays a major role in development and organ size control, and its dysregulation contributes to tumorigenesis. WWTR1 is a transcription coactivator acting downstream of the Hippo pathway. Recently, WWTR1 has been reported to be overexpressed in several human cancers including lung cancer. However, the molecular mechanism of WWTR1 regulating lung cancer aggressiveness remains ambiguous. In the present study, we analyzed the expression of WWTR1 in NSCLC cell lines and found that WWTR1 was overexpressed at both the mRNA and protein levels. Knockdown of WWTR1 by siRNA interference in A549 cells significantly inhibited cell proliferation and increased paclitaxel-induced apoptosis. On the other side, WWTR1 overexpression in HBE cell line promoted cell proliferation and inhibited apoptosis. In addition, we found that the decreased proliferation after siRNA treatment was due to cell cycle arrest. Further analysis showed that WWTR1 could induce cyclin A, connective tissue growth factor (CTGF) expression, and inhibit caspase3 cleavage. In conclusion, WWTR1 promotes malignant cell growth and inhibits apoptosis by cyclin A and CTGF regulation.

The synergistic therapeutic effect of hepatocyte growth factor and granulocyte colony-stimulating factor on pulmonary hypertension in rats.

Pulmonary arterial hypertension (PAH) is characterized by a progressive increase in pulmonary arterial pressure and vascular resistance. Despite advances in therapy for PAH, its treatment and prognosis remain poor. We aimed to investigate whether the transplantation of bone marrow mesenchymal stem cells (MSCs) overexpressing hepatocyte growth factor (HGF), alone or in combination with granulocyte colony-stimulating factor (G-CSF), attenuates the development of experimental monocrotaline (MCT)-induced PAH. Three weeks after MCT administration, rats were divided into the following groups: (1) untreated (PAH); (2) HGF treated; (3) MSCs administered; (4) HGF-MSCs treated; and (5) HGF-MSCs plus G-CSF treated. After 3 weeks, hemodynamic changes, histomorphology, and angiogenesis were evaluated. To elucidate the molecular mechanisms of vascular remodeling and angiogenesis, serum levels of transforming growth factor (TGF)-ß and endothelin-1 (ET-1) were measured, and the gene and protein expression levels of vascular cell adhesion molecule-1 (VCAM-1) and matrix metalloproteinase-9 (MMP-9) were determined. Compared with the PAH, MSC, and G-CSF groups, the HGF and HGF+G-CSF groups exhibited significantly reduced right ventricular hypertrophy and mean pulmonary arterial pressure (P < 0.05). Histologically, vessel muscularization or thickening and collagen deposition were also significantly decreased (P < 0.05). The number of vessels in the HGF+G-CSF group was higher than that in the other groups (P < 0.05). The TGF-ß and ET-1 concentrations in the plasma of pulmonary hypertensive rats were markedly lower in the HGF and HGF+G-CSF groups (P < 0.05). Furthermore, HGF induced the expression of VCAM-1, and HGF treatment together with G-CSF synergistically stimulated MMP-9 expression. Transplanted HGF-MSCs combined with G-CSF potentially offer synergistic therapeutic benefit for the treatment of PAH.

Space mutagenesis of genetically engineered bacteria expressing recombinant human interferon α1b and screening of higher yielding strains.

The aim of this study was to investigate the space mutagenesis of genetically engineered bacteria expressing recombinant human interferon α1b. The genetically engineered bacteria expressing the recombinant interferon α1b were sent into outer space on the Chinese Shenzhou VIII spacecraft. After the 17 day space flight, mutant strains that highly expressed the target gene were identified. After a series of screening of spaceflight-treated bacteria and the quantitative comparison of the mutant strains and original strain, we found five strains that showed a significantly higher production of target proteins, compared with the original strain. Our results support the notion that the outer space environment has unique effects on the mutation breeding of microorganisms, including genetically engineered strains. Mutant strains that highly express the target protein could be obtained through spaceflight-induced mutagenesis.

A multi-omic analysis of an Enterococcus faecium mutant reveals specific genetic mutations and dramatic changes in mRNA and protein expression.

BACKGROUND: For a long time, Enterococcus faecium was considered a harmless commensal of the mammalian gastrointestinal (GI) tract and was used as a probiotic in fermented foods. In recent decades, E. faecium has been recognised as an opportunistic pathogen that causes diseases such as neonatal meningitis, urinary tract infections, bacteremia, bacterial endocarditis and diverticulitis. E. faecium could be taken into space with astronauts and exposed to the space environment. Thus, it is necessary to observe the phenotypic and molecular changes of E. faecium after spaceflight. RESULTS: An E. faecium mutant with biochemical features that are different from those of the wild-type strain was obtained from subculture after flight on the SHENZHOU-8 spacecraft. To understand the underlying mechanism causing these changes, the whole genomes of both the mutant and the WT strains were sequenced using Illumina technology. The genomic comparison revealed that dprA, a recombination-mediator gene, and arpU, a gene associated with cell wall growth, were mutated. Comparative transcriptomic and proteomic analyses showed that differentially expressed genes or proteins were involved with replication, recombination, repair, cell wall biogenesis, glycometabolism, lipid metabolism, amino acid metabolism, predicted general function and energy production/conversion. CONCLUSION: This study analysed the comprehensive genomic, transcriptomic and proteomic changes of an E. faecium mutant from subcultures that were loaded on the SHENZHOU-8 spacecraft. The implications of these gene mutations and expression changes and their underlying mechanisms should be investigated in the future. We hope that the current exploration of multiple "-omics" analyses of this E. faecium mutant will provide clues for future studies on this opportunistic pathogen.

The cyclin D1 (CCND1) G870A polymorphism and lung cancer susceptibility: a meta-analysis.

Several studies have investigated the association between Cyclin D1 (CCND1) G870A genetic polymorphism and lung cancer susceptibility, but the results were inconclusive. The aim of this meta-analysis was to summarize available evidence for such a relationship. The reviewers made use of MEDLINE, EMBASE, and BIOSIS databases. The relevant data were independently extracted by two reviewers. The odds ratio (OR) with 95% confidence interval (CI) was selected as the principal outcome measure. The heterogeneity test, the publication bias test, and the sensitivity analysis were performed. Overall, a total of 10 case-control studies were included. Our meta-analysis indicated that CCND1 G870A genetic polymorphism was a risk factor for lung cancer under homozygote model (OR = 1.18; 95% CI = 1.02, 1.37), recessive model (OR = 1.21; 95% CI = 1.03, 1.41), and allele model (OR = 1.11; 95% CI = 1.02, 1.21). In the subgroup analysis by source of ethnicity, a statistical increase of lung cancer risk was found among Asian groups for allele model (OR = 1.11; 95% CI = 1.01-1.22). The present meta-analysis suggests that CCND1 G870A polymorphism may be a risk factor for lung cancer. Besides, allele A may contribute to increased lung cancer risk.

Mutations in the mitochondrial ATPase6 gene are frequent in human osteosarcoma.

To explore the polymorphisms and mutations of mitochondrial ATPase6 gene in Chinese patients with osteosarcoma and their possible association with carcinogenesis, direct DNA sequencing method was used to detect the variants of the mitochondrial ATPase6 gene in 39 patients with osteosarcoma. We found mutations of the mitochondrial ATPase6 gene in 24/39 (61.5%) of the tested osteosarcoma samples, and identified 27 variant sites in ATPase6 coding regions. We did not detect any new polymorphisms in osteosarcoma, nor was there any association between variants and the three histopathological subtypes. These data demonstrated that mtDNA mutations within the ATPase6 gene are a frequent event in Chinese patients with osteosarcoma.

Diagnostic value of dynamics serum sCD163, sTREM-1, PCT, and CRP in differentiating sepsis, severity assessment, and prognostic prediction.

OBJECTIVE: To describe the dynamics changes of sCD163, soluble serum triggering receptor expressed on myeloid cells-1 (sTREM-1), procalcitonin (PCT), and C-reactive protein (CRP) during the course of sepsis, as well as their outcome prediction. PATIENTS AND METHODS: An SIRS group (30 cases) and a sepsis group (100 cases) were involved in this study. Based on a 28-day survival, the sepsis was further divided into the survivors' and nonsurvivors' groups. Serum sTREM-1, sCD163, PCT, CRP, and WBC counts were tested on days 1, 3, 5, 7, 10, and 14. RESULTS: On the ICU admission, the sepsis group displayed higher levels of sTREM-1, sCD163, PCT, and CRP than the SIRS group (P < 0.05). Although PCT and sTREM-1 are good markers to identify severity, sTREM-1 is more reliable, which proved to be a risk factor related to sepsis. During a 14-day observation, sCD163, sTREM-1, PCT, and SOFA scores continued to climb among nonsurvivors, while their WBC and CRP went down. Both sCD163 and SOFA scores are risk factors impacting the survival time. CONCLUSION: With regard to sepsis diagnosis and severity, sTREM-1 is more ideal and constitutes a risk factor. sCD163 is of a positive value in dynamic prognostic assessment and may be taken as a survival-impacting risk factor.

[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 Pseudomonas aeruginosa strain ATCC 27853.

Pseudomonas aeruginosa is a common bacterium that can cause disease. The versatility of Pseudomonas aeruginosa enables the organism to infect damaged tissues or those with reduced immunity which cause inflammation and sepsis. Here we report the genome sequence of the strain ATCC 27853.

Whole-genome sequence of Staphylococcus aureus strain LCT-SA112.

Staphylococcus aureus is a facultative anaerobic Gram-positive coccal bacterium. S. aureus is the most common species of Staphylococcus to cause staphylococcal infections, which are very common in clinical medicine. Here we report the genome sequence of S. aureus strain LCT-SA112, which was isolated from S. aureus subsp. aureus CGMCC 1.230.

Draft genome sequence of Bacillus cereus strain LCT-BC244.

Bacillus cereus is a prevalent, soil-dwelling, Gram-positive bacterium. Some strains are harmful to humans and cause food-borne illness, while other strains can be beneficial as probiotics for animals. To gain insight into the bacterial genetic determinants, we report the genome sequence of a strain, LCT-BC244, which was isolated from CGMCC 1.230.

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.