β-lactam antibiotic binding sites in Streptococcus pneumoniae StkP kinase extracellular region / 中华微生物学和免疫学杂志

Objective:To analyze the binding ability of motifs in the serine/threonine kinase StkP extracellular region (EC-StkP) of Streptococcus pneumoniae to β-lactam antibiotics. Methods:Three motifs (SXXK) in the EC-StkP were mutated into AXXA, respectively or simultaneously. Four mutant plasmids (EC- stkp-AXXA1, EC- stkp-AXXA2, EC- stkp-AXXA3 and EC- stkp-AXXA4) were transfected into recipient cells for cloning and expression. SDS-PAGE combined with gel image analysis was used to detect the expression of the recombinant mutant proteins (EC-rStkP-AXXA1, EC-rStkP-AXXA2, EC-rStkP-AXXA3 and EC-rStkP-AXXA4). The expressed mutated proteins were extracted and purified by Ni-NTA affinity chromatography. The binding abilities of the mutant proteins to penicillin (PCN) and cefotaxime (CTX) were detected by isothermal titration calorimetry (ITC 200) and surface plasmon resonance (Biacore t200). Results:PCN and CTX could not bind to the expressed proteins with mutations in the first or the third motif (EC-rStkP-AXXA1, EC-rStkP-AXXA3, EC-rStkP-AXXA4). EC-rStkP-AXXA2 could weakly bind to CTX, but not to PCN.Conclusions:All three motifs in the EC-StkP of Streptococcus pneumoniae could bind to β-lactam antibiotics with the first and the third motifs being more important.

Hemolysin Sph2 from Leptospira interrogans amplified inflammatory response in murine macrophages J774A.1 through HMGB1 / 中华微生物学和免疫学杂志

Objective:To investigate the possible mechanism of high mobility group box-1 (HMGB1) in amplifing inflammatory responses in Leptospira interrogans hemolysin Sph2-treated J774A.1 macrophages. Methods:Recombinant Sph2 was incubated with J774A.1 macrophages. The damage of cell membrane was detected by lactate dehydrogenase(LDH) determination; the changes of cell structure were observed by cryo-electron microscope; ELISA was used to determine the expression of HMGB1. After the commercial recombinant HMGB1 was incubated with mouse J774A.1 macrophages, the phosphorylation of NF-κB, p38-MAPK and JNK signaling pathway wsa detected by Western blot, and the expression of IL-1β, IL-6, and KC (IL-8) was detected by ELISA.Results:Recombinant hemolysin rSph2 induced significant changes in the structures of J774A.1 cells, including nucleus disappearance, cell membrane structure damage, cell lysis and membrane swelling. The yields of LDH and HMGB1 also increased significantly. Phosphorylated-NF-κB, -p38-MAPK and -JNK were increased by HMGB1. The expression of IL-1β, IL-6 and KC in J774A.1 cells was up-regulated by HMGB1 and inhibited via inhibitors of NF-κB, p38-MAPK and JNK signal pathways.Conclusions:Hemolysin rSph2 damaged the membrane of J774A.1 cells, and induced the secretion of HMGB1. Secreted-HMGB1 might induce the expression of IL-1β, IL-6 and KC in J774A.1 cells via NF-κB, p38-MAPK and JNK signal pathways, thus amplifying the inflammatory responses caused by Sph2.

2019 novel coronavirus (2019-nCoV) and 2019-nCoV pneumonia / 中华微生物学和免疫学杂志

In the middle of December in 2019, a pneumonia outbreak caused by a new coronavirus, 2019 novel coronavirus (2019-nCoV), emerged in the populations in Wuhan city of China. The epidemic spreads rapidly and has been disseminated throughout the country and to 13 other counties in Asia, Europe, Oceania and North America. To accurately and deeply understand the biological characteristics, epidemiological features and pathogenicity of 2019-nCoV and related immunological characteristics, microbiological examinations and public protection measure, this study reviewed 2019-nCoV and 2019-nCoV pneumonia based on the newest relevant literatures and the newest version of National Diagnosis and Treatment Scheme of 2019-nCoV pneumonia.

2019 novel coronavirus (2019-nCoV) and 2019-nCoV pneumonia / 中华微生物学和免疫学杂志

In the middle of December in2019, a pneumonia outbreak caused by a new coronavir-us, 2019 novel coronavirus (2019-nCoV), emerged in the populations in Wuhan city of China. The epidem-ic spreads rapidly and has been disseminated throughout the country and to 13 other counties in Asia, Eu-rope, Oceania and North America. To accurately and deeply understand the biological characteristics, epide-miological features and pathogenicity of 2019-nCoV and related immunological characteristics, microbiologi-cal examinations and public protection measure, this study reviewed 2019-nCoV and 2019-nCoV pneumonia based on the newest relevant literatures and the newest version of National Diagnosis and Treatment Scheme of 2019-nCoV pneumonia.

Role and mechanism of Leptospira interrogans vWF-A gene products binding to human collagen proteins / 中华微生物学和免疫学杂志

Objective:To investigate the role and mechanism of Leptospira interrogans ( L. interrogans) vWF-A gene products binding to human collagen proteins. Methods:Bioinformatic software was used to analyze the structure and function of the vWF-A genes (LA_0012, LA_0697 and LA_4207) of L. interrogans serogroup Icterohaemorrhagiae serovar Lai strain Lai. Prokaryotic expression systems for the vWF-A domain segments in the vWF-A genes were generated. The target recombinant proteins, rLep0012, rLep0697 and rLep4207, were purified by Ni-NTA affinity chromatography and analyzed by SDS-PAGE. ELISA and surface plasmon resonance (SPR) were performed to detect the binding ability of the target recombinant proteins to humanⅠ, Ⅲ, Ⅳ and Ⅵ types of collagen proteins (hCOL1/3/4/6). Expression of the vWF-A genes at mRNA and protein levels were detected by real-time fluorescent quantitative RT-PCT and Western blot during infection of human umbilical vein endothelial cells (HUVEC) and mouse hemangioendothelioma endothelial cells (EOMA). Results:The products of vWF-A genes were vWF-A superfamily domain-containing surface or transmembrane proteins, but LA_0697 and LA_4207 genes also contained metal ion-dependent adhesion sites (MIDAS). The established prokaryotic expression systems efficiently expressed the target recombinant proteins and each of the proteins extracted by Ni-NTA affinity chromatography showed a single band in SDS-PAGE. ELISA results showed the strong binding of rLep0697 to hCOL3/6 and rLep4207 to hCOL1/4. SPR results showed the rapid binding and dissociation of rLep0697 with hCOL3/6 ( KD values=5.71×10 -8 and 5.89×10 -8 mol/L) and the rapid and stable biding of rLep4207 with hCOL1/4 ( KD values=6.4×10 -9 and 3.2×10 -9 mol/L). Expression of the vWF-A genes at both mRNA and protein levels were significantly elevated ( P<0.05) during infection of HUVEC and EOMA cells. Conclusions:The products of LA_0697 and LA_4207 genes could act as the adherence factors of L. interrogans during infection.

Roles and mechanisms of ferri ion and ferritin in the growth, reproduction and energy metabolism of Leptospira interrogans / 中华微生物学和免疫学杂志

Objective:To investigate the influence of ferri ion on the growth, reproduction and energy metabolism of Leptospira interrogans ( L. interrogans), and to identify whether the LA_2690 and LA_3598 gene products functioned as ferritin and ferroxidase. Methods:Petroff-Hausser counting method was used to analyze the influence of ferri ion deficiency on the growth and reproduction of L. interrogans serogroup Icterohaemorrhagiae serovar Lai strain 56601 in EMJH medium. Spectrophotometry and Chemiluminescence method was used to detect whether ferri ion deficiency inhibited the synthesis of DNA and ATP in L. interrogans. The structures and functions of L. interrogans LA_2690 and LA_3598 genes were analyzed using bioinformatic softwares. Prokaryotic expression systems for LA_2690 and LA_3598 genes were established and the target proteins, rLep2690 and rLep3598, were extracted by Ni-NTA affinity chromatography. The ferroxidase activity of rLep2690 and rLep3598 was detected by spectrophotometry. After L. interrogans strain 56601 was used to infect human umbilical vein endothelial cells (HUVEC) and monocytes (THP-1), changes in the expression of LA_2690 and LA_3598 genes at transcription level were detected using real-time fluorescence quantitative RT-PCR (qRT-PCR). Results:In the ferri ion-absent EMJH medium, the growth and reproduction of L. interrogans as well as the DNA and ATP synthesis levels were significantly decreased ( P<0.05). The products of LA_2690 and LA_3598 genes were predicted as bacterioferritin (Bfr) and DNA-binding ferritin containing ferroxidase diiron centers, but the latter lacked the heme-binding site and ferroxidase core. The prokaryotic expression systems for LA_2690 and LA_3598 genes could efficiently express the target recombinant proteins. Both the purified rLep2690 and rLep3598 showed a single band on SDS-PAGE. The ferroxidase activity of rLep2690 and rLep3598 was 1 238.619 U/L and 60.052 U/L, respectively. The expression of LA_2690 and LA_3598 genes of L. interrogans at mRNA level was significantly elevated during infection of the two types of cells ( P<0.05). Conclusions:Ferri ion participates in the growth and reproduction of L. interrogans as well as the synthesis of DNA and ATP. LA_2690 and LA_3598 genes were essential for L. interrogans to infect cells, and the product of LA_2690 gene possessed a stronger ferroxidase activity.

Analysis and identification of a drug resistance-associated two-component signaling system composed of Streptococcus pneumoniae StkP/CiaR proteins / 中华微生物学和免疫学杂志

Objective:To identify a two-component signaling system (TCSS) composed of β-lactam antibiotic resistance-associated intracellular CiaR and transmembrane serine/threonine kinase StkP of Streptococcus pneumoniae ( S. pneumoniae). Methods:The intracellular segment of stkP gene (IC- stkP) was amplified by PCR and the PCR product was sequenced after T-A cloning. A prokaryotic expression system for IC- stkP segment was established. SDS-PAGE was used to detect the expression of the target recombinant proteins (rIC-StkP and rCiaR) by the established prokaryotic expression system and a previously established prokaryotic expression system for ciaR gene. Ni-NTA affinity chromatography was used to purify the recombinant proteins. The rIC-StkP-captured target proteins of S. pneumoniae were identified by LC-MS/MS after Co-IP. The ability of rCiaR to bind to rIC-StkP was detected by surface plasmon resonance (SPR) and isothermal titration calorimetry (ITC). Results:The established prokaryotic expression system for IC- stkP segment could effectively express rIC-StkP. Both rIC-StkP and rCiaR after purification showed a single protein band on SDS-PAGE. CiaR could be specifically co-precipitated with rIC-StkP. Three extracted cleaved peptides were found in CiaR molecule with exactly matched sequences. SPR and ITC showed that rCiaR could strongly bind to rIC-StkP with high affinity and the KD values were 1.526×10 -9 mol/L and 1.980×10 -6 mol/L, respectively. Conclusions:S. pneumoniae CiaR could act as the downstream response regulatory protein of StkP kinase to compose StkP/CiaR TCSS.

2019 novel coronavirus (2019-nCoV) and 2019-nCoV pneumonia / 中华微生物学和免疫学杂志

In the middle of December in 2019, a pneumonia outbreak caused by a new coronavirus, 2019 novel coronavirus (2019-nCoV), emerged in the populations in Wuhan city of China. The epidemic spreads rapidly and has been disseminated throughout the country and to 13 other counties in Asia, Europe, Oceania and North America. To accurately and deeply understand the biological characteristics, epidemiological features and pathogenicity of 2019-nCoV and related immunological characteristics, microbiological examinations and public protection measure, this study reviewed 2019-nCoV and 2019-nCoV pneumonia based on the newest relevant literatures and the newest version of National Diagnosis and Treatment Scheme of 2019-nCoV pneumonia.

PAF-AH and PLA2 activity of Leptospira interrogans LA_2144 gene product / 中华微生物学和免疫学杂志

Objective To analyze the enzymatic activity of Leptospira interrogans ( L. interrogans) LA_2144 gene product to hydrolyze platelet activating factor acetylhydrolase ( PAF-AH) and phosphatidase A2(PLA2). Methods Bioinformatic softwares were used to predict transmembrane regions, signal peptides and domains of the LA_2144 gene of L. interrogans strain Lai. A prokaryotic expression system for signal peptide-free LA_2144 gene was established. The expressed target recombinant protein rLep2144 was extrac-ted by Ni-NTA affinity chromatography and then renatured. Spectrometry was used to detect the activity of rLep2144 to hydrolyze PAF-AH substrate 2-thio PAF and the Km and Kcat values as well as the activity to hy-drolyze PLA2 substrate arachidonoyl 2-thio PC. Real-time fluorescence quantitative RT-PCR and Western blot were performed to detect the transcription, protein expression and secretion of LA_2144 gene during infection of human and mouse vascular endothelial cells ( HUVEC and EOMA) with L. interrogans. Results L. interrogans LA_2144 gene contained a signal peptide and a domain belonging to SGNH hydrolase super-family, but no transmembrane regions. The established prokaryotic expression system for signal peptide-free LA_2144 gene could efficiently express rLep2144. The extracted rLep2144 was shown as a single protein fragment in separation gel and then successfully renatured. rLep2144 had a stronger PAF-AH activity with the Km and Kcat values of 688. 235 μmol/L and 0. 976/s, but its PLA2 activity was relatively weak. Expres-sion of the LA_2144 gene at mRNA and protein levels in HUVEC and EOMA was rapidly increased after the cells were infected with L. interrogans (P<0. 05) and the secretion of LA_2144 gene product could be detec-ted. Conclusions L. interrogans LA_2144 gene product had a stronger PAF-AH and a certain PLA2 activi-ty, which might involve in the hemorrhage and inflammatory response in leptospirosis.

Epidemiology characteristics analysis on HIV infection of volunteer blood donors in Shaoxing area / 中华实验和临床病毒学杂志

Objective@#To analysis HIV infection status among volunteer blood donors in Shaoxing area from 2001 to 2014, and to provide evidence for recruiting strategy of volunteer blood donors.@*Methods@#A statistical analysis was conducted on the confirmed HIV-positive cases of volunteer blood donors from 2001 to 2014 in Shaoxing area.@*Results@#36 volunteer blood donors were confirmed anti-HIV positive, and the positive rate was 0.09‰. Only 1 volunteer blood donor was confirmed anti-HIV positive before 2006, and the HIV-positive rate rose and the changes in volatility after 2006. The HIV-positive rate in Zhuji was highest compared to other blood center of Shaoxing. The HIV-positive rate in male and female were 4.14∶1, men who had sex with men remain at great risk for HIV infection.@*Conclusions@#Anti-HIV positive rate was lower among volunteer blood donors in Shaoxing area. Since 2006 years, anti-HIV positive rate increased. The anti-HIV positive rate were different in the different blood center in Shaoxing area, HIV antibody confirmatory positive is more common in young males volunteer blood donors.

Meta analysis on application effect of quality control circle in complications after PICC catheterization / 重庆医学

Objective To systematically evaluate the application effect of the quality control circle(QCC)in the complications after PICC catheterization.Methods The randomized controlled trials(RCTs)on the application effect of QCC after PICC catheter-ization were retrieved from the Cochane library,PubMed,EMBASE,Chinese Biomedical literature Database(CBM),China Academic Journal Full-text Database(CNKI),VIP and Wangfang Database by computer.The literatures were selected according to the inclu-sion and exclusion criteria.The two valuators independently retrieved and screened the literatures,extracted the data,evaluated the methodological quality of included literatures and conducted the cross check.Then the meta analysis was performed by using Rev-Man 5.3 software.Results A total of 7 914 articles were retrieved,finally 14 RCTs were included,involving 2 728 patients.The oc-currence rates of phlebitis,catheter obstruction,unplanned extubation and catheter-related blood flow infection in the intervention group were lower than those in the control group,the difference was statistically significant(OR=0.28,95% CI:0.16-0.48,P<0.01;OR=0.27,95% CI:0.17-0.42,P<0.01,OR=0.27,95% CI:0.18 -0.39,P<0.01;OR=0.25,95% CI:0.13 -0.49,P<0.01).Conclusion Using QCC is conducive to reduce the complication incidence rate after PICC catheterization.

Methicillin-resistant Staphylococcus aureus strains carrying Panton-Valentine leukocidin genes: clinical and molecular characteristics / 中华微生物学和免疫学杂志

Objective To isolate and identify the methicillin-resistant Staphylococcus aureus (MRSA) strains carrying Panton-Valentine leukocidin genes (pvl+-MRSA) from clinical samples and to further understand their molecular characteristics and infections caused by them.Methods Drug susceptibility test was performed to detect the drug resistance in 259 MRSA strains.pvl+-MRSA strains were screened out from those MRSA strains using cefoxitin slip test and mecA gene detection by PCR.Multiple PCR and multilocus sequence typing (MLST) were used for SCCmec and ST typing.Pulsed-field gel electrophoresis (PFGE) and cluster analysis were used to understand the genetic and epidemic features of the pvl+-MRSA strains.Different types of infections and diseases caused by the pvl+-MRSA strains were analyzed.ResultsAmong the 259 MRSA strains, 51 pvl+-MRSA strains were identified (19.7%, 51/259), of which 29 and 22 strains were respectively isolated from patients with community-acquired and hospital-acquired infections.ST59-SCCmecⅢ (35.3%, 18/51) was the predominant type of the 51 pvl+-MRSA strains, followed by ST59-SCCmecⅣ(25.5%, 13/51).But no predominant clone among those strains was revealed by the result of PFGE.Children, young-and middle-aged patients (≤44 years old) had a significantly higher positive rate of pvl+-MRSA than patients aged ≥45 years (P<0.05).Skin and soft tissue infection (47.1%, 24/51) was the most common disease caused by the pvl+-MRSA strains (P<0.05), followed by pneumonia (17.6%, 9/51).The pvl+-MRSA strains showed lower resistance to levofloxacin, gentamycin and rifampicine (7.8%-21.6%).No moxifloxacin-, nitrofurantoin-or linezolid-resistant pvl+-MRSA strains were identified.Conclusion The rate of pvl+-MRSA infection is high in the local population.ST59-SCCmecⅢ and ST59-SCCmecⅣ are the predominant types of pvl+ MRSA strains.Children, young-and middle-aged persons are the susceptible population.Skin and soft tissue infection and pneumonia are the common diseases caused by pvl+-MRSA.

Roles of Streptococcus pneumoniae CiaR in regulating the expression of pbps genes and csRNAs and its correlation with drug resistance / 中华微生物学和免疫学杂志

Objective To construct a ciaR gene-knockout (ΔciaR) mutant of Streptococcus pneu-moniae ( S. pneumoniae) and to investigate the effects of CiaR in CiaH/CiaR, a streptococcal two-component signal-transducing system, on the expression of genes encoding penicillin-binding proteins ( pbps genes) and cia-dependent small RNAs (csRNAs). Methods Electrophoretic mobility shift assay (ESMA) was per-formed to detect the recombinant CiaR (rCiaR)-binding pbps genes. A suicide plasmid pEVP3ciaR for ciaR gene knockout was constructed and then aΔciaR mutant was obtained through homologous recombination and insertion inactivation of the suicide plasmid, and screening with chloromycin. The mutant was identified using PCR and sequencing analysis. E-test was used to detect the minimal inhibitory concentrations ( MIC) of penicillin ( PCN) and cefotaxime ( CTX) against S. pneumoniae strains. Changes and differences in the expression of pbps genes and csRNAs in theΔciaR mutant and its wild-type strain before and after treatment with 1/4 MIC of PCN or CTX were detected using real-time quantitative RT-PCR. Results The rCiaR could bind to the promoter regions in pbp1a, pbp1b and pbp2b genes of S. pneumoniae. The ciaR gene in ΔciaR mutant was inactivated by insertion according to the results of PCR and sequencing analysis. After treatment with 1/4 MIC of PCN or CTX, the expression of pbps genes at mRNA level ( pbps-mRNAs) in theΔciaR mu-tant was significantly increased (P<0. 05), but the levels of csRNAs were significantly decreased (P<0. 05);whereas a significantly decreased pbps-mRNAs (P<0. 05) and increased csRNAs (P<0. 05) were observed in its wild-type strain. The result of E-test showed that the MICs of PCN and CTX against ΔciaR mutant were increased by 250-fold as compared with those against its wild-type strain. Conclusion The CiaR can enhance the drug resistance of S. pneumoniae to PCN and CTX through down-regulating the expres-sion of PBP1a, PBP1b and PBP2b and up-regulating the expression of csRNAs to inhibit the expression of PBPs.

Comparison of effects of nasal endoscopic adenoid body excision and conventional adenoid body shaving in the treatment of adenoid hypertrophy / 中国基层医药

Objective To compare the effect of adenoidectomy with adenoidectomy under nasal endoscope in the treatment of adenoid hypertrophy.Methods 120 cases with adenoid hypertrophy were selected as the research subjects.The patients were randomly divided into two groups by random number table,and the control group(n =60) was treated with routine adenoidectomy.The surgical treatment of the observation group(n =60) was performed under nasal endoscope.Surgical treatment,surgery related indicators (operative time,the average amount of bleeding,hospitalization time and the incidence of postoperative complications) were compared between the two groups.Before and after operation,acoustic rhinometry examination of nasopharynx was used to detect the smallest cross-sectional area and compared.Results In the observation group,the operation time,the average amount of bleeding,hospitalization time and incidence rate of postoperative complication were (5.32 ± 2.05) min,(51.05 ± 8.26) mL,(8.50 ± 2.50) d,15.00％,respectively,which in the control group were (8.56 ± 2.68) min,(78.45 ± 10.15) mL,(12.00 ± 3.50) d,36.67 ％,respectively,there were significant differences between the two groups (t =7.44,15.98,6.30,x2 =7.35,all P ＜0.05).12 months after surgery,the nasal minimal cross-sectional area of nasal pharynx in the observation group was (1.99 ± 0.51) cm2,which of the control group was (1.81 ± 0.48) cm2,there was significant difference between the two groups(t =3.99,P ＜ 0.05).Conclusion Compared with conventional adenoidectomy,endoscopic adenoidectomy in the treatment of adenoid hypertrophy has good clinical curative effect,less bleeding,shorter operative time and less postoperative complications and other advantages,it is worthy of promotion.

Expression level of miR-16 in Staphylococcus aureus sepsis and its clinical significance / 中国人兽共患病学报

We investigated correlation between the level of miR-16 expression and the severity of Staphylococcus aureus sepsis,and further explored its potentially clinical significance.Blood samples were collected from 32 patients,including each 8 cases of septic shock,severe sepsis and general sepsis,as well as 8 cases of healthy volunteers.Blood samples from 24 cases of healthy subjects with different ages were measured,and additionally 8 cases of blood samples from gram negative bacteria sepsis were also determined in current study as a control.Trizol solution for the whole blood lysis was added into blood samples,and followed by the extraction of microRNA.The expression levels of miR-16 in different groups were measured by fluorescence quantitative PCR,in which 2-Delta Ct method was used.SPSS software (version 13.0) was used to analyze the statistical differences between the groups,and further analyze the correlation between miR-16 value and the corresponding CRP and PCT values.Results showed that the expression level of miR-16 was negatively correlated with the severity of Staphylococcus aureus sepsis.There were statistically significant differences in experimental groups when compared with the control (P＜0.001),and there was also a statistically significant difference between each experimental group (P＜0.01).We found that the expression level of miR-16 was negatively correlated with CRP and PCT,the correlation coefficients were-0.561 and-0.769 respectively,and trend analysis showed that there was a significantly negative correlation.A significantly negative correlation was found between the miR-16 expression level and severity of sepsis,suggesting that miR-16 may serve as a biomarker for the severity of Staphylococcus aureus sepsis.

Streptococcus pneumoniae StkP kinase: binding ability with β-lactam antibiotics and correlation with drug resistance / 中华微生物学和免疫学杂志

Objective To investigate the correlation between Streptococcus pneumoniae (S.pneumoniae) StkP kinase and drug resistance and to analyze the binding ability of StkP extracellular region (EC-StkP) to β-lactam antibiotics.Methods A stkP gene knockout (ΔstkP) mutant was constructed from S.pneumoniae strain ATCC6306 by insertional inactivation method.E-test was performed to detect the minimum inhibitory concentrations (MIC) of penicillin (PCN) and cefotaxime (CTX) against ΔstkP mutant and its wild-type strain.Bioinformatic softwares were used to predict the EC-StkP of S.pneumonia strain ATCC6306,to generate the three-dimensional structure model of EC-StkP and to analyze the correlation between the structure and functions of EC-StkP.PCR was performed to amplify the extracellular segment of stkP (EC-stkP) gene and the product of it was sequenced after T-A cloning.A prokaryotic expression system of EC-stkP gene was constructed.SDS-PAGE in combination with a gel image analysis system was used to detect the expression of the recombinant EC-StkP (EC-rStkP).The expressed EC-rStkP was extracted by Ni-NTA affinity chromatography.The binding abilities of EC-rStkP to PCN and CTX were detected by isothermal titration calorimetry (VT-ITC) and surface plasmon resonance (Biacore).Results S.pneumonia strain ATCC6306 was sensitive to PCN (MIC=0.06 μg/ml) and CTX (MIC=0.12 μg/ml),but its ΔstkP mutant was resistant to the two antibiotics (PCN MIC=16 μg/ml,CTX MIC=32 μg/ml).The 295 aa segment was predicted as the extracellular region at C-end of StkP of S.pneumoniae strain ATCC6306,containing four penicillin-binding proteins and Ser/Thr kinase-associated (PASTA) domains.The cloned EC-stkP segment and the EC-stkP segment in GenBank shared 99.6% similarity in nucleotide sequence and 100% in amino acid sequence.The constructed prokaryotic expression system for EC-stkP gene expressed EC-rStkP in soluble form.Both PCN and CTX could bind to EC-rStkP and CTX was better than PCN in term of binding ability.Conclusion The stkP gene of S.pneumonia is closely related to drug resistance and the encoded protein,Ser/Thr kinase StkP,can recognize and bind to β-lactam antibiotics.

Advance in research of characteristics and action mechanism of microRNAs from prokaryotes / 中国人兽共患病学报

microRNAs is a group of small non-coding RNAs that play a negative regulation role in expression of target genes at post-transcriptional level by inhibition or degradation of target mRNAs after combination of the seed sequence (SS) in microRNAs with the SS-binding sequences usually located at 5'ends of target mRNAs.microRNAs was firstly found in Caenorhabditis elegans.Subsequently,many different microRNAs in eukaryocytes were revealed.In eukaryocytes,microRNA precursors are transcribed at first and then become functional microRNAs with 21-23 nt in size after splice.Most of eukaryocytic microRNAs combime with the sequences at 3'end of target mRNAs that cause the translation inhibition or degradation of the mRNAs.In the recent years,many different prokaryocytes,such as bacteria,have been confirmed to possess microRNAs.However,the microRNAs in prokaryotes such as bacteria are 50-400 nt in size and have the biological activity without splice.Moreover,the characteristics,action sites and mechanisms of the prokaryotic microRNAs have some certain diversity compared to the eukaryotic microRNAs.Our review briefly introduce the major regulation mechanisms of gene expression as well as the general characteristics of microRNAs and their regulation mechanisms of gene expression in prokaryocytes and eukaryocytes,which will provide a basis for further and profound study on the gene expression regulation and pathogenic mechanisms of prokaryotic microbial pathogens.

Linezolid resistance in methicillin-resistant Staphylococcus epidermidis strains isolated in Hangzhou ;area / 中华微生物学和免疫学杂志

Objective To investigate the mechanism of linezolid resistance in methicillin-resistant Staphylococcus epidermidis ( MRSE) strains isolated in Hangzhou area. Methods Twenty-three linezolid-re-sistant Staphylococcus epidermidis ( LRSE) strains were isolated from the patients with septicaemia, urinary tract infection or infectious pleuritis in several hospitals in Hangzhou area during May, 2013 to April, 2015. The minimal inhibition concentrations ( MICs) of thirteen different antibiotics against the LRSE strains were detected by using E-test. Pulsed-field gel electrophoresis ( PFGE) and cluster analysis were performed for homology analysis. Correlations between linezolid resistance in the LRSE strains and G2576T mutation at theⅤ functional region of 23S rRNA gene or cfr gene were determined by PCR and sequencing analysis. Re-sults The MICs of linezolid to 15 LRSE strains were higher than 256 μg/ml while to the other 8 LRSE strains were 6 or 8 μg/ml. All of the 23 LRSE strains were resistant to both oxacillin and cefoxitin. Among the LRSE strains with high linezolid MICs (MIC>256 μg/ml), LRSE1 and LRSE2, LRSE3-LRSE6 and LRSE9-LRSE12 respectively belonged to the same clone line and came from the same hospital. All of the 23 LRSE strains carried the cfr gene. Moreover, the G2576T mutation at theⅤfunctional region of 23S rRNA gene was detected in the 15 LRSE strains with high linezolid MICs ( MIC>256 μg/ml ) , but not in the 8 strains with lower linezolid MICs ( MIC=6 or 8 μg/ml) . Conclusion There are significant differences in linezolid resistance among LRSE strains isolated in Hangzhou area. The LRSE strains are methicillin-resist-ant coagulase negative Staphylococcus ( MRCNS) strains and widely distributed. The linezolid resistance in LRSE strains is related to the G2576T mutation at theⅤfunctional region of 23S rRNA gene and cfr gene.

Investigation of application and needs' survey of mobile App health software in the patients with respiratory chronic disease / 中国实用护理杂志

Objective To investigate the application and needs' survey of mobile App health software in the patients with respiratory chronic disease. To make mobile App health software development more targeted and practical in the near future. To provide the foundation for continuous nursing service. Methods A survey research method was adopted in which self-designed questionnaires were administered to 163 patients with respiratory chronic disease from respiratory ward and outpatient clinic. Results Totally 119(73.0%) patients used smartphone, the mean score of experience in using mobile phones was (32.4 ± 14.1), which was in the medium range. There were 80 patients had ever installed and used this kind of App. The frequency of use of mobile App health software was Breathing Exercises App, Healthy Exercise App, Healthy Diet App and Medicine Remind App. The major reason for using of these App was disease prevention, self health care, disease and health monitoring and rehabilitation exercises. There were 120 patients would like to install App health software specific to respiratory chronic disease. They hope the characters of these App were simple operated, practical and without product placement. These App health software should include following function:timely feedback and guidance, providing practical method and help to register. Conclusion Most patients with respiratory chronic disease had the hardware basis and experience basis of using mobile App health software. More targeted and practical mobile App health software for the patients with respiratory chronic diseases should be developed to provide the foundation for continuous nursing service and patient′s self-management.

The relationship between professional identity and professional self-concept among nurses / 中国实用护理杂志

Objective To describe the status of nurses′professional identity and the self-concept and to explore the relationship between nurses′professional identity and the self-concept. This will be the base for intervening nurses′professional identity. Methods A convenience sample of 250 nurses from one major hospital in Beijing was recruited. The Macleod Clark Professional Identity Scale and the Professional Self-Concept Instrument were introduced. A standard translation procedure was carried out. Results A total of 250 questionnaires were sent out, 241 questionnaires were withdrawed with an effective rate of 96.4%. The mean score of nurses′professional identity was 42.54±8.70, which was at moderate level. The mean score of nurses′professional self-concept was 86.28 ±22.86, also at moderate level, among which,knowledgescores highest (25.91±6.00), leadership scored 20.84±8.02, inter-personal relationship scored (20.28±4.18), caring scored the lowest (19.25±4.67). There was significant difference among the professional identity in the different departments (P<0.05) , while the same results were not seen in professional self-concept. Nurses′professional identity was positively correlated with professional self-concept′s four dimensions (P<0.05). Conclusions The nurse managers should pay attention to the cultivation of professional self-concept in the training of nurses in order to improve the professional identity of nurses and the whole nurses′development.