Xuelin Zhang

Genome Sequence of Pseudomonas aeruginosa Strain LCT-PA220, Which Was Selected after Space Flight by Using Biolog's Powerful Carbon Source Utilization Technology

ABSTRACT To explore the changes of Pseudomonas aeruginosa in space flight, we present the draft genome sequence of P. aeruginosa strain LCT-PA220, which originated from a P. aeruginosa strain, ATCC 27853, that traveled on the Shenzhou-VIII spacecraft.

Use of genome sequencing to assess nucleotide structure variation of Staphylococcus aureus strains cultured in spaceflight on Shenzhou-X, under simulated microgravity and on the ground

The extreme environment of space could affect microbial behavior and may increase the risk of infectious disease during spaceflight. However, the molecular genetic changes of methicillin-resistant Staphylococcus aureus (MRSA) in response to the spaceflight environment have not been fully clarified. In the present study, we determined the draft genome sequences for an ancestral S. aureus strain (LCT-SAO) isolated from a clinical sample and three derivative strains, LCT-SAS, LCT-SAM and LCT-SAG, cultured in parallel during the spaceflight Shenzhou-X, under simulated microgravity and on the ground, respectively. To evaluate the impact of short-term spaceflight on the MRSA strains, comparative genomic analysis was implemented. Genome-based mapping of toxin genes and antibiotic resistance genes confirmed that these strains have the conventional pathogenicity and resistance to drugs, as none of the strains showed significant changes in these regions after culturing in the three different environments; this result suggests that spaceflight may not change bacterial virulence or drug resistance. Thirty-nine strain-specific sequence variants (SVs) were identified throughout the genomes, and the three derivatives exhibited almost the same mutation rates. Fifty-nine percent of SVs were located in the intergenic regions of the genomes, indicating that S. aureus may have an extremely robust repair mechanism responsible for recognizing and repairing DNA replication mismatches. It is noteworthy that strain LCT-SAS, cultured in space, presented the most unique SVs (n=9) and shared the fewest SVs with LCT-SAM (n=5) and LCT-SAG (n=4). Furthermore, we identified 10 potential deletion regions and 2 potential insertion regions, with LCT-SAS appearing more fragile than other strains by this measure. These results suggest that the environment of space is inherently complicated, with multiple variables, and cannot be simulated in a simple manner. Our results represent the first analysis of nucleotide structure variation of S. aureus strains in a spaceflight environment and also provide a valuable insight for understanding the mutation strategies of MRSA on earth.

Genome Sequence of Escherichia coli Strain LCT-EC52, Which Acquired Changes in Antibiotic Resistance Properties after the Shenzhou-VIII Mission

ABSTRACT Escherichia coli is a ubiquitous opportunistic pathogen that colonizes the lower intestines of humans and causes several diseases, such as septicemia, pneumonia, and urinary tract infections. Here, we present the draft genome sequence of E. coli strain LCT-EC52, which originated from E. coli strain CGMCC 1.2385 and acquired changes in antibiotic resistance following travel on the Shenzhou-VIII spacecraft.

The virulence of Streptococcus pneumoniae partially depends on dprA

Streptococcus pneumoniae is one of the most frequent opportunistic pathogens worldwide. DNA processing protein A (DprA) is an important factor involved in bacterial uptake and DNA integration into bacterial genome, but its role in S. pneumoniae virulence remains unclear. The aim of this study was to characterize the effects of the pneumococcal dprA gene on the pathogenesis of S. pneumoniae. To construct a dprA-deficient pneumococcal strain, the dprA gene of the S. pneumoniae strain D39 was inactivated. The virulence of this dprA-deficient strain, designated ΔD39, was compared with that of the wild-type strain by evaluating their respective capabilities to adhere to human pulmonary epithelial cells (PEC-A549) and by analyzing their choline-binding protein expression levels. In addition, the expression profiles of genes associated with virulence and host survival assays were also conducted with the mutant and the wild-type strain. Our results indicate that the capability of ΔD39 to adhere to the PEC-A549 airway cells was significantly lower (p < 0.01) compared with D39. Additionally, the 100-KD choline-binding protein was not detected in ΔD39. The addition of competence-stimulating peptide (CSP) lead to a significantly reduction of psaA mRNA expression in the dprA-deficient mutant and an increased level of psaA transcripts in the wild-type strain (p < 0.01). The median survival time of mice intraperitoneally infected with ΔD39 was significantly higher (p < 0.01) than that of mice infected with D39. The results of this study suggest that DprA has a significant effect on virulence characteristics of S. pneumoniae by influencing the expression of choline-binding protein and PsaA.

Draft genome sequence of Sphingomonas paucimobilis strain LCT-SP1 isolated from the Shenzhou X spacecraft of China

Sphingomonas paucimobilis strain LCT-SP1 is a glucose-nonfermenting Gram-negative, chemoheterotrophic, strictly aerobic bacterium. The major feature of strain LCT-SP1, isolated from the Chinese spacecraft Shenzhou X, together with the genome draft and annotation are described in this paper. The total size of strain LCT-SP1 is 4,302,226 bp with 3,864 protein-coding and 50 RNA genes. The information gained from its sequence is potentially relevant to the elucidation of microbially mediated corrosion of various materials.

Tumor-preventing activity of aspirin in multiple cancers based on bioinformatic analyses

Background Acetylsalicylic acid was renamed aspirin in 1899, and it has been widely used for its multiple biological actions. Because of the diversity of the cellular processes and diseases that aspirin reportedly affects and benefits, uncertainty remains regarding its mechanism in different biological systems. Methods The Drugbank and STITCH databases were used to find direct protein targets (DPTs) of aspirin. The Mentha database was used to analyze protein–protein interactions (PPIs) to find DPT-associated genes. DAVID was used for the GO and KEGG enrichment analyses. The cBio Cancer Genomics Portal database was used to mine genetic alterations and networks of aspirin-associated genes in cancer. Results Eighteen direct protein targets (DPT) and 961 DPT-associated genes were identified for aspirin. This enrichment analysis resulted in eight identified KEGG pathways that were associated with cancers. Analysis using the cBio portal indicated that aspirin might have effects on multiple tumor suppressors, such as TP53, PTEN, and RB1 and that TP53 might play a central role in aspirin-associated genes. Discussion The results not only suggest that aspirin might have anti-tumor actions against multiple cancers but could also provide new directions for further research on aspirin using a bioinformatics analysis approach.

Genome Sequence of Klebsiella pneumoniae Strain LCT-KP182, Which Acquired Hemolytic Properties after Space Flight

ABSTRACT The Klebsiella pneumoniae strain LCT-KP182 acquired hemolytic properties after space flight. Here, we present the draft genome sequence of this strain.

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

ABSTRACT 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.

Genome Sequence of Staphylococcus aureus Strain LCT-SA67, a Space Flight Strain with Altered Carbon Source Utilization Properties.

ABSTRACT An increasing number of studies have confirmed that space flight environments can have a significant effect on a variety of microbial properties. To explore the effect of these environments on Staphylococcus aureus, we present the draft genome sequence of an S. aureus strain, named LCT-SA67, which was isolated after space flight.

Genome Sequence of Enterococcus faecium Strain LCT-EF297, Which Has Specific Biochemical Features.

ABSTRACT An Enterococcus faecium strain was sent into space on the Shenzhou-VIII craft. After space flight, the strain E. faecium LCT-EF297 was selected based on its metabolic properties.