Search

Multidrug-resistant (MDR) Staphylococcus aureus biofilms have emerged as a serious threat to human health. Recently, the development of antibiotic replacement therapy has gained much attention due to the potential application of bacteriocin. The present study sought to evaluate the antibacterial effect of bacteriocin XJS01 against MDR S. aureus, a previously reported bacteriocin against S. aureus strain 2612:1606BL1486 (S. aureus_26, an MDR strain demonstrated here), and its potential application as an antibiofilm agent. The minimum bactericide concentration of XJS01 against MDR S. aureus_26 was 33.18 μg/mL. XJS01 exhibited excellent storage stability and resistance against acid and reduced the density of established MDR S. aureus_26 biofilm. The hemolytic and HEK293T cytotoxicity activities of XJS01 and the histological analyses in mice confirmed its safety. Moreover, XJS01 effectively disrupted the MDR S. aureus_26 biofilm established on the skin wound surface and reduced the biofilm-isolated bacteria, thereby decreasing the release of pro-inflammatory cytokines and the proliferation of alternatively activated macrophages. Compared to mupirocin, XJS01 exhibited an excellent therapeutic effect on mice skin wounds, confirming it to be a potential alternative to antibiotics.

Antibacterial activity and mechanism of action of bacteriocins against bacteria that cause pork contamination remain unclear. Here, antibacterial activity of bacteriocin LFX01 against two important indicator strains (i.e., Staphylococcus aureus and Escherichia coli) and its mechanism of action were investigated. The results showed antibacterial activity of LFX01 against growth and biofilm formation of S. aureus_26 (strain 2612:1606BL1486) and E. coli_02 (strain CMCC(B)44102). Additionally, the results demonstrated that LFX01 could decrease cell metabolic activity, disrupt cell membrane permeability and integrity, and trigger leakage of intracellular contents (e.g., K

Background New strategies are urgently needed to deal with the growing problem of multidrug-resistant bacterial pathogens. As the natural viruses against bacteria, recently, bacteriophages have received particular attention. Here, we identified and characterized a novel peptidoglycan hydrolase named MMPphg by decoding the complete genome sequence of Meiothermus bacteriophage MMP17, which was isolated in Tengchong hot spring in China and contains a circular genome of 33,172 bp in size and a GC content of 63.4%. Findings We cloned the MMPphg gene, overproduced and purified the phage lytic protein, which contains a highly conserved M23 metallopeptidase domain and can be activated by Mg2+ and Zn2+. MMPphg is capable of withstanding temperatures up to 70 °C, and preserved more than 80% of its activity after a 30 min treatment between 35 and 65 °C. More interestingly, by disrupting bacterial cells, MMPphg exhibits surprising antimicrobial activity against both Gram-negative and Gram-positive pathogenic bacteria, especially antibiotic-resistant strains such as Escherichia coli O157, Staphylococcus aureus and Klebsiella pneumonia. Conclusions In the current age of mounting antibiotic resistance, these results suggest the great potential of MMPphg, the gene product of bacteriophage MMP17, in combating bacterial infections and shed light on bacteriophage-based strategies to develop alternatives to conventional antibiotics for human or veterinary applications.

The genome sequence of a novel Meiothermus bacteriophage, named MMP7, which was isolated from Tengchong hot spring in Yunnan Province of China and belongs to the family Myoviridae, was sequenced in this study. To the best of our knowledge, this is the first reported genome sequence of a Meiothermus phage, which has a circular DNA genome of 32,864 bp and a GC content of 64%. The MMP7 genome contains 53 putative protein-encoding genes but no rRNA or tRNA genes, and it exhibits low overall sequence similarity and no significant homology to phage genomes whose sequences are publicly available, suggesting that MMP7 is a novel phage. Consistent with current taxonomic results, whole-genome-based phylogenetic analysis revealed that Meiothermus phage MMP7 has close evolutionary relationship to Thermus phages. Together, our results could be helpful for discovering new thermostable antimicrobial agents and understanding the evolution and genetic diversity of Meiothermus phages in extreme environments.

Developing new strategies to replace or supplement antibiotics to combat bacterial infection is a pressing task in the field of microbiological research. In this study, we report a lytic enzyme named P9ly deriving from the bacteriophage PSD9 that could infect multidrug-resistant

Few bacteriocins with antibacterial activity against Shigella flexneri have been reported. Here, a novel bacteriocin (LFX01) produced by Lactiplantibacillus plantarum strain LF-8 from the intestine of tilapia was purified and extensively characterized. LFX01 possesses a molecular weight of 1049.56 Da and an amino acid sequence of I-T-G-G-P-A-V-V-H-Q-A. LFX01 significantly inhibited S. flexneri strain 14 (S. flexneri_14) growth. Moreover, it exhibited excellent stability under heat and acid-base stress, and presented sensitivity to a variety of proteases, such as proteinase K, pepsin, and trypsin. The minimum inhibitory concentration (MIC) of LFX01 against S. flexneri_14 was 12.65 μg/mL, which was smaller than that of most of the previously found bacteriocins. Furthermore, LFX01 significantly inhibited (p < 0.05) S. flexneri_14 cells and decreased their cell viability. In addition, LFX01 could significantly (p < 0.05) inhibit biofilm formation of S. flexneri_14. Scanning electron microscopy analysis presented that the cell membrane permeability of S. flexneri_14 was demolished by LFX01, leading to cytoplasmic contents leakage and cell rupture death. In summary, a novel bacteriocin of lactic acid bacteria (LAB) was found, which could effectively control S. flexneri in both planktonic and biofilm states.

Bupleuri Radix, serving as the sovereign medicinal in many antidepressant compound preparations, has been proved effective in treating depression in mice, but its effect on the intestinal flora remains unclear. The present study aimed to investigate the effects of Bupleurum chinense(one of the original materials of Bupleuri Radix) on the behaviors and the diversity of intestinal flora of depressed mice. A depression mouse model was induced by repeated social defeat stress. Specifically, C57 BL/6 J male mice were exposed to the attack from the CD-1 mice. Then, C57 BL/6 J male mice were divided into a depression group and a B. chinense group, with normal saline and B. chinense administered(ig) respectively. Sucrose preference test and tail suspension test were conducted during and after the experiment respectively, to analyze the effects of B. chinense on the behaviors of the depressed mice. The feces were collected after the experiment. The V3-V4 16 S rDNA regions of intestinal flora of mice in each group were sequenced by Ion S5 TMXL for the analysis of the number of operational taxonomic units(OTUs), richness, alpha and beta diversity indexes, and differential phyla and genera. The results indicated that B. chinense could decrease depressive-like behaviors of mice, increase sucrose preference, and shorten the time of immobility in tail suspension test. After B. chinense intervention, the relative abundance of Firmicutes was significantly decreased, while that of Bacteroidetes was increased at the phylum level. At the genus level, the relative abundance of Lactobacillus and Lachnoclostridium decreased(Plt;0.05), while that of Bacteroides, Alistopes, etc. was elevated(Plt;0.05). The findings demonstrate that B. chinense can regulate the intestinal flora and improve the depressive-like behaviors of mice with depression.

Amphioxus has been widely used as a model for the comparative immunology of vertebrates. Studies have reported that gene expression changes in the amphioxus gill in response to biotic stress, such as microbial and their mimic challenge, but little is known about how gene expression is affected by abiotic stress in the marine environment, such as nitrite. A lack of information regarding gene expression response to abiotic stress hinders a comprehensive understanding of gill defense response in amphioxus. Here, RNA sequencing was used to carry out gene expression profiling analyses of Branchiostoma belcheri gills under nitrite stress. Six libraries were created for the control and treatment groups, including three biological replicates. In total, 2416 differently expressed genes (DEGs) were detected in response to nitrite stress, of which 1522 DEGs were up-regulated in the treatment group in comparison to the control, while the remaining 894 DEGs were down-regulated genes. Functional enrichment revealed that these DEGs are primarily involved in disease, innate immunity, xenobiotic biodegradation and metabolism, and biomolecular processes and apoptosis. We screened 11 key nitrite-responsive DEGs to detect their expression responses to nitrite stress at different time points, and validate the sequencing data using real time quantitative PCR. The results indicated that the expression of gene encoding CYP3A, POD, CASPR1, GST, MAO, DDH, and XDH/XO were induced, while those encoding MRC, GT, DNASE1L, and RIPK5 were reduced, to participate in the anti-nitrite response. This study provides a useful resource for research of molecular toxicology in amphioxus under environmental stress.

The egg-pathogenic fungus Purpureocillium lilacinum parasitizes on nematode eggs, and thus, it is used as a good biocontrol agent against plant root-knot nematodes. However, little is known about the transcriptional response of P. lilacinum while infecting nematode eggs. This study presents the whole transcriptome sequencing of P. lilacinum and transcriptome-wide gene expression analysis of P. lilacinum upon infecting the eggs of Meloidogyne incognita compared to non-infecting controls. A transcriptomic library of P. lilacinum was used as reference gene set and six transcriptomic libraries of the non-infecting control and P. lilacinum infecting M. incognita eggs were constructed, respectively, comprising three biological replicates of each. A total of 1,011 differently expressed genes (DEGs) were identified in the infecting samples, including 553 up-regulated and 458 down-regulated genes compared to the non-infecting control samples. Furthermore, functional enrichment analysis exhibited that these DEGs were primarily involved in oxidative phosphorylation, oxidoreductase activity, and metabolic processes. Fifteen DEGs were randomly selected to verify the RNA sequencing results through quantitative real-time polymerase chain reaction (qPCR). The study focused on P. lilacinum genes that were strongly expressed upon infecting M. incognita eggs. These DEGs were primarily involved in detoxification, parasitic behavior, and nutritional utilization. This study contributes significantly to the understanding of the molecular mechanisms underlying the parasitic action of P. lilacinum on nematode eggs and provides a valuable genetic resource for further research on parasitic behavior of P. lilacinum. Notably, this study examined the transcriptomics of P. lilacinum infecting M. incognita eggs at only one time point. Since there were fungi at different stages of the infection process at that time point, the transcriptional profiles are not precisely examining one specific stage in this process.

New strategies against antibiotic-resistant bacterial pathogens are urgently needed but are not within reach. Here, we present in vitro and in vivo antimicrobial activity of TSPphg, a novel phage lysin identified from extremophilic Thermus phage TSP4 by sequencing its whole genome. By breaking down the bacterial cells, TSPphg is able to cause bacteria destruction and has shown bactericidal activity against both Gram-negative and Gram-positive pathogenic bacteria, especially antibiotic-resistant strains of Klebsiella pneumoniae, in which the complete elimination and highest reduction in bacterial counts by greater than 6 logs were observed upon 50 &mu, g/mL TSPphg treatment at 37 &deg, C for 1 h. A murine skin infection model further confirmed the in vivo efficacy of TSPphg in removing a highly dangerous and multidrug-resistant Staphylococcus aureus from skin damage and in accelerating wound closure. Together, our findings may offer a therapeutic alternative to help fight bacterial infections in the current age of mounting antibiotic resistance, and to shed light on bacteriophage-based strategies to develop novel anti-infectives.

Recently, Streptococcus agalactiae has become a major pathogen leading to Streptococcosis. To understand the physiological responses of zebrafish (Danio rerio) to S. agalactiae, the intestinal microbiota composition of the intestine (12 and 24 h post-infection, hpi, respectively) in zebrafish infected with S. agalactiae were investigated. The intestinal bacterial composition was analyzed using PacBio high-throughput full-length 16S rRNA gene sequencing. The most predominant bacteria in the zebrafish intestine were the Fusobacteria phylum and Sphingomonas genus. S. agalactiae infection affected the composition of partially intestinal microbiota. At the species level, the relative abundance of the pathogenic intestinal bacteria Aeromonas veronii, S. agalactiae, and Clostridium tarantellae significantly increased after S. agalactiae infection (p < 0.05), while that of the beneficial intestinal bacteria Bacillus licheniformis, Comamonas koreensis, and Romboutsia ilealis significantly decreased (p < 0.05), showing that S. agalactiae infection aggravates the zebrafish disease through promoting abundance of other intestinal pathogenic bacteria. This study is the first PacBio analyses of the zebrafish intestinal microbiota community under pathogenic infection. Results suggest that the S. agalactiae infection alters the intestinal flora structure in zebrafish.

Planktonic Salmonella Enteritidis and their biofilm threaten human health through the food chain. However, the resources of bacteriocins with activity against this threat are still limited. This study purified and characterized a novel bacteriocin (AMYX6) produced by the Bacillus amyloliquefaciens strain JDF-17, isolated from the intestine of the Nile tilapia (Oreochromis niloticus). The analysis results of AKTA Purifier and nano liquid chromatography coupled with tandem mass spectrometry uncovered a molecular mass of 1323.73 Da and an amino acid composition of PVFLSDHIRIQ. AMYX6 inhibited the strain of S. Enteritidis CMCC(B)50335 (S. Enteritidis_35). AMYX6 also showed good resistance to heat and acid-base treatments, and was found to be sensitive to proteases such as trypsin, protease K, papain, and pepsin. The minimum inhibitory concentration of AMYX6 against S. Enteritidis_35 was 12.17 μg/mL, which is lower than the levels reported for most bacteriocins. Furthermore, exposure to AMYX6 significantly inhibited (p

The novel bacteriocin JS17 was obtained from Bacillus subtilis JSX-5, isolated from blueberry (Vaccinium uliginosum) ferments. JS17 was purified by AKTA Purifier, semi-preparative reversed-phase high performance liquid chromatography, and nano liquid chromatography coupled with tandem mass spectrometry, in succession. Its molecular mass was 652.37 Da and its amino acid sequence was identified as L-F-R-A-F. A homology BLAST search confirmed JS17 as a novel bacteriocin. JS17 was found to have an extensive antibacterial activity spectrum against both Gram-positive and Gram-negative bacteria. JS17 showed heat tolerance, and it was highly stable over pH 2–10 and was sensitive to proteinase K and pepsin. This indicates that JS17 exhibits protein properties and has application potential under high temperature and acid-base conditions. The minimum inhibitory concentration and minimum bactericide concentration of JS17 against Escherichia coli were 10.56 μg/mL and 22.03 μg/mL, respectively, which is lower than that of most previously described bacteriocins. Furthermore, scanning electron microscopy showed that JS17 bactericidally destroyed the cell membrane integrity of E. coli, resulting in cell dissolution and impaired membrane permeability. This study first purified B. subtilis bacteriocin from fruit ferments, suggesting the potential for using JS17 as a food bio-preservative.

Many studies have reported that behavior and bioluminescence of fireflies could be affected by changes in environment conditions. However, little is known about how the deterioration of the aquatic environment affects aquatic fireflies, particularly with respect to molecular responses following exposure to water pollutants, such as benzo(a)pyrene (BaP), which is a key indicator in environmental risk assessment because of the hazards it poses. Here, whole transcriptome sequencing and gene expression analysis were performed on freshwater fireflies (Luciola leii) exposed to BaP (concentration of 0.01 mg/L). Four transcriptomic libraries were constructed for the control and treatment groups, including two biological replicates. From the mixed pools (each pool contains 60 individuals from three time points), a total of 54,282 unigenes were assembled. Furthermore, 329,337 of Single-nucleotide Polymorphisms (SNPs) and 1324 of Simple Sequence Repeats (SSRs) were predicted using bioinformatics, which is useful for the future development of molecular markers. Subsequently, 2414 differently expressed genes (DEGs) were identified in response to BaP stress in comparison to the control, including 1350 up-regulated and 1064 down-regulated DEGs. Functional enrichment showed that these DEGs are primarily related to innate immunity; xenobiotic biodegradation and response, biomacromolecule metabolism, biosynthesis, and absorption. Eight key BaP-responsive DEGs were screened to survey the dynamic changes of expression in response to BaP stress at different time points, and to validate the RNA sequencing data using quantitative real-time PCR. The results indicate that the expression of genes encoding UGT, CYP3A, CYP9, CYP6AS5 and ADHP were induced, while those encoding UGT2B10L, PTGDS, and ALDH were reduced, to participate in response to the BaP exposure and potentially help counteract the adverse effects of BaP. This investigation provides insight into the toxicological response of fireflies to the occurrence of water deterioration.

Bacteriocins are known to inhibit various foodborne bacteria and their biofilms; however, few bacteriocins with activity against food-derived Staphylococcus aureus have been reported. Here, a novel bacteriocin (XJS01) from the Lactobacillus salivarius strain CGMCC2070 was obtained, purified, and extensively characterized. Molecular mass and amino acid composition of XJS01 were 666.31 Da and F–S-G-L-A-G-D, respectively. XJS01 inhibited the S. aureus strain 2612:1606BL1486 (S. aureus_26), which was originally isolated from chicken meat. Also, XJS01 showed good resistance to heat treatment, and was only susceptible to pepsin treatment. The minimum inhibitory concentration of XJS01 against S. aureus_26 was 9.85 μg/mL, which is lower than previously reported levels for most described bacteriocins. Furthermore, exposure to XJS01 also decreased viability and significantly inhibited (p

Larval aquatic fireflies in fresh water are adversely affected by water pollutants such as benzo(a)pyrene (BaP). However, their response to BaP stress at the microRNA (miRNA)-regulatory level remains unknown. Here, transcriptomes containing 31,872 genes and six miRNA transcriptional profiles were obtained for Aquatica wuhana larvae, and comparative analysis was performed between larvae exposed to BaP (0.01 mg/L) and unexposed controls. Fifteen of 114 miRNAs identified via bioinformatics were detected as differentially expressed (DEMs) upon BaP exposure. Analysis results of predicted target genes of DEM suggests that BaP exposure primarily triggered transcriptional changes of miRNA associated with five major regulatory categories: 1) osmotic balance, 2) energy metabolic efficiency, 3) development, 4) xenobiotic metabolism (oxidative stress), and 5) innate immune response. Based on six innate immune- and xenobiotic metabolism-related pathways enriched by the predicted DEM targets, 11 key BaP-responsive DEMs were further screened to investigate dynamic changes of expression in response to BaP stress at five time points, and also to validate the miRNA sequencing data using quantitative real-time PCR. This study provides valuable information for the protection of firefly resources and supplements the understanding of miRNA regulatory mechanisms in response to water deterioration.

Recently, high cell-density (HCD) cultivation has become an important tool for production of many microbial products. However, to the best of our knowledge, no study regarding HCD fermentation, overproduction and purification of thermostable bacteriophage lysin has been reported. Here, by employing a glucose-limited fed-batch strategy, we performed high density fermentation of the host Escherichia coli BL21(DE3) cells, compared the efficiency of high pressure homogenization, ultrasonication and thermolysis in bacterial cell disruption after HCD cultivation, and purified TSPphg, a thermostable lysin derived from extremophilic bacteriophage TSP4. On the 20-L scale, the overproduction level of TSPphg was up to 67.8 ± 0.7%. In total, we obtained a broth titer of 3322.8 ± 26 mg/L TSPphg with a purity of 95.5 ± 0.7% from a bacterial cell mass of 86.3 ± 4.9 g/L after 26 h of fermentation. The overall productivity of TSPphg was 127.8 ± 1 mg/L/h. Additionally, the antimicrobial activity of purified TSPphg against both Gram-negative (Escherichia coli O157) and Gram-positive (Staphylococcus aureus) pathogenic bacteria was further confirmed by scanning electron microscope analysis. Summarily, for the first time, we have established a relatively stable and efficient HCD cultivation and purification process for recovery of thermostable lysins from extremophilic Thermus bacteriophages. Our results provide insights into the strategies for time-saving and cost-effective production of antimicrobial proteins to replace or supplement antibiotics in the current age of mounting antibiotic resistance.

Mercury is a widely used heavy metal that causes pollution to aquatic environments and severely affects the health of fish. Little is known about how heavy metal pollutants affect fish, particularly for gene expression within important organs such as the intestine. Herein, whole transcriptome sequencing was performed on zebrafish (Danio rerio) intestine tissue after HgCl2 (HGC, 30 μg/L) exposure. A total of 2,257 differentially expressed genes (DEGs) were identified, including 1,788 up- and 469 down-regulated genes. Functional enrichment analysis revealed that these DEGs were primarily related to xenobiotic biodegradation, biomacromolecule metabolism, development, oxidative defense, and immune response. Ten key HGC-responsive DEGs were screened to survey the dynamic changes of expression in response to HGC exposure at different time points, and were also used to validate RNA sequencing data using quantitative real-time PCR (qPCR). Results indicate that the expression of genes encoding UGT1AB, GSTT1B, GSTO1, GSTM2, UGT5G1, GSTT1A, GSTR, GSTM3, GSTA1, and GSTP2 were significantly upregulated in response to the HGC exposure, and potentially help to counteract the adverse effects of HGC. This study provides insight into fish molecular toxicological responses to heavy metals and method on environmental risk assessment.

The role of the gut microbiome in animal health has become increasingly evident. Although the structure of the gut microbiome of A. mellifera is well known, little is known about the dynamic change across different developmental stages. In this study, we explored the dynamic changes of the gut microbiota of A. mellifera at different developmental stages covering the whole life cycle using high-throughput 16S rRNA gene sequencing. The results indicated that the core (shared) gut microbiota changes significantly among different developmental stages. The diversity of the bacterial community in workers among different ages was significantly different. In addition, by comparing the core gut microbiota among different-aged workers, we found that newly emerged workers had fewer core microbiota. Three genera, Gilliamella, Frischella, and Snodgrassella, were significantly colonized at 1 day poste mergence (dpe); Lactobacillus, Bifidobacterium, Commensalibacter were significantly colonized at 3 dpe and significantly reduced with Gilliamella. Lactobacillus kunkeei and Bartonella were significantly colonized at 12 dpe and were significantly decreased with Lactobacillus helsingborgensis. Commensalibacter and Bifidobacterium were significantly decreased at 25 dpe, and Bacteroides, Escherichia-Shigella, and Porphyromonadaceae were significantly decreased between 19 and 25 dpe. Our results reveal the succession of the gut microbiota of workers from birth to senescence, which provides a theoretical basis for further exploring the roles of gut microbiota during different developmental stages.

Amphioxus is a key model for studying comparative immunity of vertebrates. Circular RNA (circRNA), as RNAs with a circular structure, has received little attention until recently, where several studies have reported that circRNA expression changes are involved in the immune response in animals. However, circRNA and its immune role in amphioxus have not been previously studied. Here, circRNAs in Chinese amphioxus (Branchiostoma belcheri) were sequenced, and 1859 circRNAs were identified using two algorithms (find_circ and CIRI). The analysis of miRNA target sites on circRNAs showed that 332 circRNAs may function as miRNA sponges. Furthermore, we identified circRNAs that were conserved between B. belcheri and vertebrates, tracing the origin of these circRNAs within chordates. Additionally, in combination with several key antiviral immune (poly(I:C), pIC) pathways identified in our previous B. belcheri studies, nine circRNAs potentially involved in these pathways were identified using bioinformatic predictions. Among these nine circRNAs, eight were selected to examine their expression response in B. belcheri challenged by pIC in comparison to control using real-time quantitative PCR. The results showed that four circRNAs were induced as part of the antiviral response against pIC, while expression of two circRNAs was decreased, and the expression levels of the remaining two were not significantly altered after pIC challenge. This work is the first to identify circRNAs and reveal their antiviral role in amphioxus. Therefore, it opens a new window to explore the comparative immunology of circRNAs in chordates and the regulatory roles of circRNAs in antiviral immunity in amphioxus.

Amphioxus, a cephalochordate found in sand habitats in shallow in-shore seawaters, has been widely used as a model in comparative immunology of chordates. However, the role of microRNAs (miRNAs) in amphioxus under abiotic stress, particularly xenobiotics with strong toxicity, remains largely unknown. Here, a widespread marine contaminant, benzo(a)pyrene (BaP) is used to evaluate its toxic effects on miRNA expression of amphioxus. Six small RNA libraries were sequenced from Branchiostoma belcheri. A total of 144 known and 157 novel miRNAs were identified using deep sequencing and bioinformatics approaches. A total of 58 differentially expressed miRNAs (DEMs) were screened, including 25 up- and 33 down-regulated DEMs under BaP stress. Target genes possibly regulated by DEMs were predicted, and their functional enrichment analyses were performed. Targets of DEMs are primarily involved in xenobiotic and cellular homeostasis, catabolic and transport process. They could be largely linked to nine immune- and toxin detoxification-related pathways, including metabolism of xenobiotics by cytochrome P450, drug metabolism-other enzymes, and drug metabolism-cytochrome P450, etc. Furthermore, quantitative real-time PCR (qRT-PCR) analysis for 12 key BaP-responsive DEMs validates the accuracy of deep sequencing. Experiments were then conducted to investigate their expression responses to BaP stress at different time intervals in detail to further determine their expression dynamic in responses of B. belcheri towards BaP exposure. This study, to the best of our knowledge, investigates the regulatory roles of miRNAs in the toxicological response of amphioxus for the first time, providing valuable information for the protection of lone existing cephalochordate amphioxus.

Aquatic insects are well adapted to freshwater environments, but the molecular basis of these adaptations remains largely unknown. Most firefly species (Coleoptera: Lampyridae) are terrestrial, but the larvae of several species are aquatic. Here, larval and adult transcriptomes from Aquatica leii (freshwater) and Lychnuris praetexta (terrestrial) were generated to test whether the genes associated with metabolic efficiency and morphology have undergone adaptive evolution to fresh water. The aquatic fireflies had a significantly lower ratio of nonsynonymous to synonymous substitutions than the terrestrial insects, indicating a genomewide evolutionary constraint in the aquatic fireflies. We identified 341 fast-evolving genes and 116 positively selected genes in the aquatic fireflies. Of these, 76 genes exhibiting both fast evolution and positive selection were primarily involved in ATP production, energy metabolism and the hypoxia response. We identified 7,271 differentially expressed genes (DEGs) in A. leii (adults versus larvae) and 8,309 DEGs in L. praetexta (adults versus larvae). DEGs specific to the aquatic firefly (n = 1,445) were screened via interspecific comparisons (A. leii versus L. praetexta) and were significantly enriched for genes involved in metabolic efficiency (e.g., ATP production, hypoxia, and immune responses) and certain aspects of morphology (e.g., cuticle chitin, tracheal and compound eye morphology). These results indicate that sequence and expression-level changes in genes associated with both metabolic efficiency and morphological attributes related to the freshwater lifestyle contributed to freshwater adaptation in fireflies. This study provides new insights into the molecular mechanisms of aquatic adaptation in insects.

Henosepilachna vigintioctopunctata is a vegetable pest that has spread worldwide. It belongs to the Coccinellidae family, whose members exhibit remarkable diversity, both in terms of their diets and the colored spots that appear on the elytra in the adult stage. Transcriptomic data from H. vigintioctopunctata at different life stages would be useful for further investigating the genetic basis of this dietary diversity and the formation of the colored spots in ladybird beetles, as well as revealing the population dynamics of H. vigintioctopunctata, which could be useful in pest control. Here, we generated a comprehensive RNA-seq data set (a total of ~24 Gb of clean data) for H. vigintioctopunctata by sequencing samples collected at different life stages. We characterized the transcriptomes of each of the four life stages (egg, larva, pupa, adult) and generated a high-coverage pool by combining all the RNA-seq reads. Furthermore, we identified a catalog of simple sequence repeat (SSR) markers. This represents the first study to collect transcriptome data from all life stages of a ladybird beetle. Machine-accessible metadata file describing the reported data (ISA-Tab format)

The spatiotemporal control of HOX gene expression is dependent on positional identity and often correlated to their genomic location within each loci. Maintenance of HOX expression patterns is under complex transcriptional and epigenetic regulation, which is not well understood. Here we demonstrate that HOTTIP, a lincRNA transcribed from the 5′ edge of the HOXA locus, physically associates with the CCCTC-binding factor (CTCF) that serves as an insulator by organizing HOXA cluster into disjoint domains, to cooperatively maintain the chromatin modifications of HOXA genes and thus coordinate the transcriptional activation of distal HOXA genes in human foreskin fibroblasts. Our results reveal the functional connection of HOTTIP and CTCF, and shed light on lincRNAs in gene activation and CTCF mediated chromatin organization.

Bacteriophage endolysins have long been demonstrated to be effective enzybiotics, and have the potential value in the areas of food, agricultural, and industrial science. Traditionally, extraction of recombinant proteins from bacterium E. coli is achieved by chemical, biological or mechanical disruption methods. Here, we present heat treatment, a simple and highly effective method that differs from the conventional ones, for disruption of E. coli cells to extract recombinant TSPphg, an endolysin originated from thermophilic bacteriophage TSP4. In addition, we found that exogenous TSPphg treatment is able to disrupt E. coli cell and release its intracellular proteins, suggesting its great potentiality to be developed as an alternative bacterial cell disruption method. Moreover, the large scale purification of TSPphg by heat treatment can be carried out directly in fermentation broth in situ without complex downstream processing, which may make it a more applicable approach for commercial scale processes. Our findings shed light on recovery of recombinant thermostable proteins and strategy of bacterial cell disruption.

Amphioxus, a basal chordate, is widely considered to be an existing proxy of the invertebrate ancestor of vertebrates, and it exhibits susceptibility to various pathogen infections and pathogenic mimic challenges. Here, in order to understand more clearly its antibacterial mechanisms, we analyzed the ribosomal RNA (rRNA)-depleted transcriptome of Chinese amphioxus (Branchiostoma belcheri) infected with Vibrio parahaemolyticus (V. p.) via next-generation deep sequencing technology (RNA-seq). We identified a total of 3214 differentially expressed genes (DEGs) by comparing V. p.-infected and control transcriptome libraries, including 2219 significantly up-regulated and 995 significantly down-regulated DEGs in V. p.-infected amphioxus. The DEGs with the top 10 most dramatic expression fold changes after V. p. infection, as well as 53 immune-related DEGs (IRDs) belonging to four primary categories of innate immunity were analyzed further. Through gene ontology (GO) and pathway enrichment analysis, DEGs were found to be primarily related to immune processes, apoptosis, catabolic and metabolic processes, binding and enzyme activity, while pathways involving bacterial infection, immune signaling, immune response, cancer, and apoptosis were overrepresented. We validated the RNA-seq results by detecting the expression levels of 10 IRDs using qRT-PCR, and we surveyed the dynamic variation in gene expression for these IRDs at 0, 6, 12, 24, and 48 h after V. p. treatment. Subsequently, according to the RNA-seq results, the presence of a primitive Toll-like receptor (TLR)-mediated antibacterial immune signaling pathway was predicted in B. belcheri. This study provides valuable information regarding antibacterial immunity for further research into the evolution of immunity in vertebrates and broadens our understanding of the innate immune response against bacterial invasion in amphioxus.

Proteases have diverse applications in a wide variety of industries, such as in detergent, leather, food, pharmaceutical and silk. The extracellular cold-active protease was purified from the psychrotrophic bacteriumSerratiasp. WJ39 from a meat factory. The protease was cold-active with a molecular mass of 47.6 kDa estimated on SDS-PAGE. It showed an optimal activity at pH of 8 and was stable at pH 6 to 10, while its optimal temperature was 37°C and it was stable at 0-25°C, even remained 35% residual activity at 0°C. The protease was totally inhibited by PMSF which was telling that the purified enzyme was a serine protease. The properties like moderate thermostability, activity in a broad pH range and resistance to metal ions make this enzyme a suitable candidate for the possible use in food and leather industry.

Objective To observe the clinical effects of acupoint sticking therapy for lumbar intervertebral disc herniation.

ThxynA, an extracellular xylanase of T. halotolerans YIM 90462 T , was purified to homogeneity from a fermentation broth by ultra-filtration, ammonium sulphate precipitation, hydrophobic chromatography and ion exchange chromatography. The purified xylanase has a molecular mass of 24 kDa and is optimally active at 80 °C and pH 6.0. The enzyme is stable over a broad pH range (pH 6.0–10.0) and shows good thermal stability when incubated at 70 °C for 1 h. The K m and V max values of the enzyme are 11.6 mg/mL and 434 μmol mg −1 min −1 , respectively, using oat spelt xylan as a substrate. Moreover, the enzyme seemingly has both xylanase activity and cellulase activity. These unique properties suggest that it may be useful for industrial applications.

A thermophilic bacterium, designated strain RHA1T, was isolated from a sediment sample collected from a hot spring in Tengchong county, Yunnan province, south-west China, and was characterized by using a polyphasic approach. Based on its phenotypic and phylogenetic characteristics, strain RHA1T was affiliated to the genus Laceyella. The strain formed white aerial and yellow–white substrate mycelia, bearing single endospores on short sporophores. The cell-wall peptidoglycan contained meso-diaminopimelic acid. Whole-cell hydrolysates contained ribose and glucose. The major fatty acids were iso-C15 : 0 (62.39 %) and anteiso-C15 : 0 (17.55 %). The predominant menaquinone was MK-9. The G+C content of the genomic DNA of strain RHA1T was 47.9 mol%. Based on DNA–DNA hybridization data, chemotaxonomic characteristics and differential physiological properties, strain RHA1T is considered to represent a novel species of the genus Laceyella, for which the name Laceyella sediminis sp. nov. is proposed; the type strain is RHA1T ( = DSM 45263T = CCTCC AA 208058T).