The formation of Staphylococcus epidermidis biofilm on the surface of medical biomaterials may resist the antibiotics treatment and cause chronic infection,which has become a research focus in recent years.Multiple genes constitute complex regulatory network which affect the biofilm formation,and play different roles in the different stages of biofilm formation.Accessory gene regulator (agr) is one of the most important genes in the process of biofilm formation.The process of bacterial biofilm formation,research status of regulation mechanism of agr system and its related genes in the formation of biofilm are reviewed,to provide reference of using agr as a target for the treatment of staphylococcus epidermidis biofilm related infections.

Staphylococcus epidermidis(SE)is the main opportunistic pathogen in nosocomial infections.It usually enter the body along with biomedical materials and adheres to the surface of biomaterials to form bacterial bi06lm.SE bi06lm bears high organized multi.cell colony structure.Bacterial biofilm iS the key reason for refractoriness of biomaterial originated infection.This paper gives an overview of the research progresses in biomaterial related infection,including SE ica operon,formation of biofilm,biofilm treatment,and SO on.Our review shows that studies of SE biofilm were COnfined to the mutated strain from laboratory and growth pattern of plankton and thus the natural clinical pathogenic procedure of SE can't be fully described.Further study should be carried out on formation of SE biofilm and treatment of infections related to the clinical application of biomaterials.

Staphylococcus epidermidis is a commensal bacteria which inhabits on the surface of human skin and mucous membrane.It has been demonstrated that staphylococcus epidermidis is a major opportunistic pathogen that can cause clinical biomaterial related infection and plays an important role in biomaterial implantation associated infections.The main pathogenic factor is the formation of the bacterial biofilm on surface of medical biomaterial.The formation of bacterial biofilm can resist the defense reaction and antibiotic treatment effectively so that leading to the biomaterial implantation associated infection which is difficult to cure thoroughly,and make the infections become chronic,persistent and repetitive.Nowadays,the infections caused by Staphylococcus epidermidis have caused high clinical mortality.Staphylococcus epidermidis biofilm formation,the regulations of intercellular adhesion gene (ica) operon and accessory gene regulator (agr) gene on the formation of biofilm and their functions in clinical biomaterial related infections are reviewed in this article.

Objective To construct a qseC-deleted mutant strain of E.coli by Red recombination and to study the effect of qseC gene on biofilm formation in the mutants.Methods The chloramphenicolresistant gene flanked by homologues of target genes was amplified by PCR and electro-transformed into E.coli MC1000.When induced by L-arabinose,the plasmid pKD46 could express three recombinant proteins of λ-prophage,which led to the replacement of target gene(qseC) with chloramphenicol-resistant gene.Then the chloramphenicol-resistant gene was eliminated by FLP-promoted recombination events.The biofilm formation of wild-type and mutant strain was detected by crystal violet staining.Results The qseC-deleted mutant of E.coli was confirmed by various PCR and DNA sequencing.Gene qseC was completely deleted.There was no significant difference in growth ability between the qseC mutant strain and the wild-type strain MC1000.The biofilm formation of wild-type and mutant strain was quantified by crystal violet staining.The absorbance determined with a plate reader at 570 nm was 1.00±0.15 and 0.47±0.10 respectively.Conclusion The qseC-deleted mutant of E.coli was constructed successfully.And the qseC gene plays an important role in regulation of biofilm formation in E.coli.

Objective To study the effect of epinephrine on biofilm formation of the qseC-deleted mutant of Escherichia coli on biomaterial.Methods The strains used in this study are Escherichia coli MC1000 and MC1000AqseC.LB was used for all the experiments.To determine the effect of epinephrine on motility,halos were measured in LB medium at 37℃ in the presence of epinephrine(50 μmol/L).LB with epinephrine and without epinephrine were used,and then the experiment of bacterial biofilm formation on PVC material was taken.The relative amount of biofilm was estimated.The thickness of bacterial community and bacterial community quantity in the unit area on PVC materials were measured by confocal laser scanning microscope( CLSM),and the surface structure of biofilm formation was observed by scanning electron microscope(SEM).Results The mutant strain formed less biofilm than the wild-type strain in LB.The increment in motility of wild-type strain due to epinephrine addition was shown,but mutant strain is unaffected.Similarly,biofilm formation of the wild-type strain was increased by epinephrine,but epinephrine did not affect the biofilm formation of the qseC mutant.The CLSM and SEM showed that epinephrine stimulated biofilm formation of wild-type strain on PVC materials,but had no effect on qseC-deleted mutant strain.Conclusion Epinephrine increases Escherichia coli biofilms on biomaterials through qseC.

Objective To investigate the role of quorum sensing Escherichia coli regulator C (qseC) in intestinal bacterial translocation in rats subjected to hemorrhagic shock.Methods Thirty Sprague-Dawley rats,weighing 250-300 g,were randomly divided into 5 groups (n =6 each):control group (group C),MC1000-sham shock group (group M-SS),MC1000qseC-sham shock group (group △-SS),MC1000-hemorrhagic shock group (group M-HS),and MC1000△ qseC-hemorrhagic shock group (group △-HS).The rats drank 150 μg/ml of disinfect water containing streptomycin in 3 consecutive days to inhibit the autochthonous flora in the intestinal tract.From 4th day,the rats were fed with Escherichia Coli MC1000 or MC1000△ qseC 1 ml/100 g by gastric perfusion once a day for another 3 consecutive days in the other 4 groups,while the rats were fed with normal saline instead in group C.Hemorrhagic shock was induced by blood-letting.The mesenteric lymph node (MLN),spleen and liver specimens were obtained at 24 h after operation for bacterial culture and the bacteria were identified.Bacterial translocation from gut to MLN,spleen and liver was observed and the number of bacteria in MLN,spleen and liver tissues were counted.Results The rate of bacterial translocation was significantly higher,and the number of bacterial colonies in MLN,spleen and liver tissues and the total number of bacterial colonies were significantly larger in groups M-HS and △-HS than in group C,and in group M-HS than in groups M-SS and △-SS (P ＜ 0.05).The rate of bacterial translocation was significantly lower,and the number of bacterial colonies in MLN,spleen and liver tissues and the total number of bacterial colonies were significantly smaller in group △-HS than in group MHS.Conclusion QseC is involved in the intestinal bacterial translocation following hemorrhagic shock in rats.

ObjectiveTo investigate the diagnosis and the treatment of male interstitial cystitis (IC) to improve the efficiency.MethodsEighteen cases of IC male patients treated from Jan 2010 to Dec 2010 who suffered from suprapnbic pain urinary frequency and urgency were analyzed retrospectively.All these patients were misdiagnosed as category Ⅲ chronic prostatitis.According to the NIDDK diagnostic criteria of IC,Pelvic Pain and Urgency Frequency (PUF) scoring,potassium sensitivity test (PST),and cystoscopy under anaesthesia were used to establish the diagnosis of IC.24 h urinary diary,routine uronoscopy,prostate fluid routine and bacterial culture examination were taken before the treatment of hydrodistention and intravesical instillation of heparin.ResultsAfter the follow-up 12 to 25 months ( average,19 months),the symptoms improved distinctly.The PUF scoring was 19.2 ±4.1 before treatment and 13.6 ±2.4 after treatment respectively ( P ＜ 0.01 ).24 hours' frequency and amount of urination were (7.5 ± 4.3)times and (241.7 ±45.3) ml after treatment compared with (11.5 ±3.9) times and (159.5 ±30.8) ml before treatment ( P ＜ 0.01 ).ConclusionsThe male IC and chronic prostatitis share the same symptoms.They can be differentiated by the IC diagnosis.The treatment of hydrodistention alone with oral tolterodine tartrate sustained release tablets and intravesical instillation of heparin can evidently improve the symptoms of the male IC patients.

Objective To evaluate the relationship between quartz's deposit and expression of NF-κB in non-small cell lung cancer (NSCLC) lung tissues in Xuanwei, Yunnan Province, and to clarify the role of quartz in Xuanwei NSCLC's carcinogenic mechanism. Methods As research objects, the lung tissues of NSCLC and lung benign lesions after surgical resection were collected from July 2009 to September 2015 at the Third Affiliated Hospital of Kunming Medical University. Firstly, the transmission electron microscopic (TEM) with energy dispersive X-ray analyzer (EDS) was used for observation of crystalline deposit and local pathological changes. Secondly, expression level of NF-κB had been analysed and a correlation analysis with particle size of SiO2 crystal in the same lung sample was made. Results The occurrence rates of quartz in Xuanwei NSCLC lung tissues were above non-Xuanwei NSCLC and benign lung tissues (P<0.01);the average particle size of SiO2 crystal was (226 ± 120) nm × (237 ± 163) nm in Xuanwei NSCLC group and it was smaller than the other two groups; In Xuanwei NSCLC group, the expression level of NF-κB was significantly higher than non-Xuanwei and benign lung tissues (P< 0.01), but there was no significant difference between cancer tissues and normal lung tissues in the group (P>0.05). The expression level of NF-κB was generally increasing when quartz 's size became smaller. Conclusion Quartz 's deposit may play a certain role in carcinogenic mechanism of lung cancer in Xuanwei, the smaller the particle size, the greater the cytotoxicity.

BACKGROUND: It is confirmed that pathogenicity of biomaterials-centered infection is positive correlated to bacterial biofilm formation of Staphylococcus epidermidis on the surface of catheter-related materials. OBJECTIVE: To analyze the relations between expressions of central venous catheter-related Staphylococcus epidermidis icaA, icaD, transforming growth factor β1 (TGF-β1) and formation of bacterial biofilm. METHODS: The type of Staphylococcus epidermidis in lung cancer cases with catheter-related bloodstream infections (CRBSI) was indentified, followed by bacterial genomic DNA extraction. The expression of biofilm formation-related genes icaA, icaD mRNA and phenotype of biofilm were detected by PCR. The serum TGF-β1 levels in cases with or without CRBSI were measured by enzyme-linked immunosorbent assay.RESULTS AND CONCLUSION: The expression of Staphylococcus epidermidis operon icaA and icaD gene was positive correlated to biofilm formation in lung cancer cases with CRBSI (P < 0.01); particularly, the TGF-β1 levels in CRBSI cases were greater than that of non-CRBSI cases (P < 0.05). The results demonstrated that, central venous catheter infection causes positive Staphylococcus epidermidis icaA and icaD gene expressions in lung cancer cases and is prone to form biofilm, high level of peripheral TGF-β1 may play a positive role in bacterial biofilm formation.

Xuanwei district in Yunnan Province of China has pretty high incidence of lung cancer in China, even a- round the world. Studies have shown that there exists a close relationship between lung cancer and local indoor air pollution caused by Bituminous coal. Considering that the indoor air pollution in Xuanwei District is caused by "open fireplace", an indoor air pollution simulation system was designed, and an F344 rats lung damage model was estab- lished for this indoor air pollution fireplace. The model is based on indoor air pollution simulation system with signal multiplexer control and multi-channel acquisition, and mining PID algorithm was used for polynomial fitting to each test point, and a relatively constant PM2. 5 air pollution status was simulated. The results showed that the system could simulate a variety of states of air pollution, provide a new test method for evaluation of human injury caused by indoor air pollution and a new idea for the study of the incidence of lung cancer in Xuanwei district and other places.
Air Pollution, Indoor ; analysis ; Animals ; China ; Coal ; adverse effects ; Humans ; Incidence ; Lung ; drug effects ; pathology ; Lung Neoplasms ; epidemiology ; Models, Biological ; Particulate Matter ; analysis ; Rats ; Rats, Inbred F344