Transcriptomic Analysis Revealed Antimicrobial Mechanisms of Lactobacillus rhamnosus SCB0119 against Escherichia coli and Staphylococcus aureus.

Lactic acid bacteria were reported as a promising alternative to antibiotics against pathogens. Among them, Lactobacillus rhamnosus could be used as probiotics and inhibit several pathogens, but its antibacterial mechanisms are still less known. Here, L. rhamnosus SCB0119 isolated from fermented pickles could inhibit bacterial growth or even cause cell death in Escherichia coli ATCC25922 and Staphylococcus aureus ATCC6538, which was mainly attributed to the cell-free culture supernatant (CFS). Moreover, CFS induced the accumulation of reactive oxygen species and destroyed the structure of the cell wall and membrane, including the deformation in cell shape and cell wall, the impairment of the integrity of the cell wall and inner membrane, and the increases in outer membrane permeability, the membrane potential, and pH gradient in E. coli and S. aureus. Furthermore, the transcriptomic analysis demonstrated that CFS altered the transcripts of several genes involved in fatty acid degradation, ion transport, and the biosynthesis of amino acids in E. coli, and fatty acid degradation, protein synthesis, DNA replication, and ATP hydrolysis in S. aureus, which are important for bacterial survival and growth. In conclusion, L. rhamnosus SCB0119 and its CFS could be used as a biocontrol agent against E. coli and S. aureus.

Impact of the Consumption of Tea Polyphenols on Early Atherosclerotic Lesion Formation and Intestinal Bifidobacteria in High-Fat-Fed ApoE-/- Mice.

There is an increasing interest in the effect of dietary polyphenols on the intestinal microbiota and the possible associations between this effect and the development of some cardiovascular diseases, such as atherosclerosis (AS). However, limited information is available on how these polyphenols affect the gut microbiota and AS development. This study was designed to evaluate the modulation of dietary tea polyphenols (TPs) on intestinal Bifidobacteria (IB) and its correlation with AS development in apolipoprotein E-deficient (ApoE-/-) mice. Fifty C57BL/6 ApoE-/- mice were randomized into one of the five treatment groups (n = 10/group): control group fed normal diet (CK); a group fed a high-fat diet (HFD); and the other three groups fed the same HFD supplemented with TPs in drinking water for 16 weeks. The total cholesterol and low-density lipoprotein cholesterol (LDL-C) were decreased significantly (P < 0.05) after TP interference. In addition, the TP diet also decreased the plaque area/lumen area (PA/LA) ratios (P < 0.01) in the TP diet group. Interestingly, copies of IB in the gut of ApoE-/- mice were notably increased with TP interference. This increase was dose dependent (P < 0.01) and negatively correlated with the PA/LA ratio (P < 0.05). We conclude that TPs could promote the proliferation of the IB, which is partially responsible for the reduction of AS plaque induced by HFD.

Verrucosispora lutea sp. nov., isolated from a mangrove sediment sample.

A novel Gram-positive, aerobic, spore-forming actinobacterium, designated strain YIM 013T, was isolated from a mangrove sediment sample and subjected to a polyphasic taxonomic study. The peptidoglycan type was A1gamma and the major whole-cell sugars contained glucose and xylose. The phospholipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, phosphatidylinositol mannosides and some unknown phospholipids. The predominant menaquinone was MK-9(H4). The major fatty acids were iso-C15:0 and iso-C16:0. The genomic DNA G+C content was 69.3 mol%. blast search results based on an almost-complete 16S rRNA gene sequence showed that strain YIM 013T had the highest similarity with Verrucosispora gifhornensis DSM 44337T (98%) and phylogenetic analysis revealed that strain YIM 013T should be assigned to the genus Verrucosispora. The mean level of DNA-DNA relatedness between strain YIM 013T and V. gifhornensis DSM 44337T was 38.2%. Based on its phenotypic and genotypic characteristics, strain YIM 013T (=CCTCC AA207012T=KCTC 19195T) is proposed to be the type strain of a novel species, Verrucosispora lutea sp. nov.

[Construction and expression of anti-human integrin alphavbeta3 scFv].

AIM: To construct single chain antibody (scFv) gene of mAb E10 against human integrin alphavbeta3. METHODS: The VH and VL genes were amplified from hybridoma cells secreting mAb E10 by RT-PCR and connected with the use of linker (Gly4Ser)3 to assemble scFv gene. The scFv gene was cloned into prokaryotic expression vector pTIG-TRX and expressed in E. coli BL21 (DE3). RESULTS: SDS-PAGE analysis showed the expressed recombinant protein with relative molecular mass (Mr) being 31,000. Western blot confirmed that the protein was labeled with His6. scFv protein was expressed as soluble protein under the condition of a small amount of IPTG induction and culture at lower temperature. The purity of the protein purified through Ni-NTA agarose metal affinity resin column was over 91%. The purified protein could bind to the human integrin alphavbeta3 by ELISA confirmation. CONCLUSION: scFv against human integrin alphavbeta3 has been successfully constructed and expressed,which lays the foundation for further clinical research.

[Clinical characteristics of non-steroidal anti-inflammatory drugs associated gastroduodenal ulcer bleeding].

OBJECTIVE: To study the clinical characteristics of non-steroidal anti-inflammatory drugs (NSAIDs) associated gastroduodenal ulcer bleeding. METHODS: Patients who were hospitalized in our ward because of gastroduodenal bleeding from Jan, 1997 to Dec, 2001 were divided into two groups according to consumption of NSAIDs or not in the week previous to the onset of bleeding. RESULTS: 446 patients were investigated with 86 in NSAIDs group and 360 in non-NSAIDs group. There was no significant difference in sex, way of bleeding, history of peptic ulcer, bleeding site in stomach or duodenum, presence of erosion and the need of endoscopic injection therapy or not between the two groups. However, the patients in NSAIDs group were older than those in non-NSAIDs group. Hemoglobin level was lower in NSAIDs group (P = 0.004). There was more gastric ulcer and complex ulcer in the NSAIDs group than in non-NSAIDs group (P < 0.001). NSAIDs users had more ulcers (P < 0.001). Helicobacter pylori (Hp) was present in 72.5% of the non-NSAIDs group and 53.4% of the NSAIDs group (P = 0.001). In an another study, we found that age of the patients or Hp state didn't affect the clinical characteristics of NSAIDs ulcer bleeding. CONCLUSIONS: The clinical characteristics of NSAIDs associated gastroduodenal bleeding should be better understood so as to decrease the occurrence of NSAIDs ulcer and its complication.