Objective To investigate the immune response of mucosal immunization of new chitosan(CS) nanoparticles coating DNA vaccine. Methods The chitosan nanoparticles containing plasmid DNA encoding H. pylori lipoprotein Lpp20 gene were prepared using a complex coacervation method and then its speciality were analyzed. We then administered the naked plasmid DNA and chitosan-DNA nanoparticles to 6-week-old female BALB/c mice by intranasal or oral mucosal routes to observe the humoral and cellular immune responses. Results Naked plasmid pcDNA3.1 ( + )/Lpp20 and chitosan-pcDNA3. 1 ( + )/Lpp20 nanoparticles both induced effective immune response in mice through mucosal vaccination. Specific IgG and sIgA antibodies of chitosan-pcDNA3. 1 ( + )/Lpp20 nanoparticles groups were higher than that of naked pcDNA3.1 ( + )/Lpp20 group. The concentration of cytokines IFN-γ and IL-4 in cultural supernatant of T lymphocytes from chitosan-pcDNA3. 1 ( + )/Lpp20 nanoparticles immunized mice increased greatly than that of control groups. After stimulated by corresponding antigen, the stimulation index of intranasal or oral delivery of chitosan-pcDNA3. 1 ( + )/Lpp20 nanoparticles group was significantly higher than that of pcDNA3.1( + )/Lpp20 group, CS group and PBS control group. Moreover, systemic and mucosal immune responses in mice induced by intranasal immunization were stronger than that of oral immunization. Conclusion Chitosan nanoparticles enhanced the immune response of pcDNA3.1 ( + )/Lpp20 DNA vaccine by intranasal or oral administration in BALB/c mice. Compared to oral administration, intranasal delivery of chitosan-pcDNA3.1 ( + )/Lpp20 DNA nanoparticles could induce stronger cellular and humoral immune responses in BALB/c mice.

Objective To explore the role of ADSCs and PRP in soft tissue defect repairing .Methods Harvest adipose tissue from inguinalis fat pad of SD rats ,isolation ,culture ,and identification the ADSCs through three differentiation method .Take 30 male SD rats about 6-7 weeks old randomly .Randomly selected 12 rats been take blood from heart .Preparation the PRP with modi-fied appel method .To count platelet of whole blood and PRP under microscope .Take the remaining rats .Divided the rat into 3 groups(n=6 in each group) randomly ,of which group A treatment with ADSCs and PRP ;Group B treatment with ADSCs ;Group C treatment whit PRP .Selected one side of skin defect wound for test randomly and the relative side skin defect is for control ,Handle all of the control wound to group D ;Observe the grow th of granulation tissue on the wound surface ;observe the inflammatory sur-rounding and the degree about epithelial .statistical analysis and record the wound size ,and calculation the shrinkage rate of wound in different periods .Record the time of completely healing time .Histologic observation of the wound healing tissue .Results Plate-let counting showed platelet of PRP is 5 .21 times than whole blood .The wound completely healed time :group A (18 .25 ± 1 .44 ) days ,group B(19 .13 ± 1 .28)days ,group C(19 .72 ± 0 .87)days ,group D(22 .31 ± 1 .65) days ,The time of each treatment group and control group was significantly obvious(P< 0 .05) .At 3 ,7 ,11 and 15 days after experimental treatment ,compared with the control group the experiment group of wound contraction rate was significantly obvious (P<0 .05) .Conclusion Application of AD-SCs with PRP can enhance the quality and shorten the wound healing time than used them alone .

Objective To investigate antimicrobial resistance among gram-positive cocci in China in 2008.Methods From June 2008 to December 2008,1171 consecutive and non-repetitive gram-positive cocci were collected from 12 teaching hospitals.The MICs of antibacterial agents was determined by agar dilution method.Results The prevalence of MRSA and methicillin-resistant coagulase-negative Staphylococci(MRSCoN) was 49.9%(232/465) and 74.0%(179/242),respectively.The MRSA prevalence ranged from 33.3% to 65% in different regions.About 71.1%(108/152) of Staphylococcus aureus from respiratory tract specimens,48.3%(28/58) of Staphylococcus aureus from blood samples,and 36%(68/189) of Staphylococcus aureus from the pus,wound and sterile body fluid samples were resistant to methicillin.The susceptible rates of MRSA to trimethoprim/sulfamethoxazole(SXT) and chloramphenicol were 81.5%(183/232) and 89.7%(208/232).Susceptibility to gentamicin, erythromycin, clindamycin, tetracyclines,rifampicin,and quinolones were from 3.9% to 35.0%.All Staphylococci isolates were susceptible to vancomycin,teicoplanin,and linezolid.Three vacomycin-resistant Enterococcus faecium strains were found in this study.About 96.2%(101/105) of Enterococcus faecalis and 97%(130/134) of Enterococcus faecium were susceptible to linezoild.Fifty-one out of 105 of Enterococcus faecalis(48.6%)and 101 out of 134 Enterococcus faecium(75.4%)were resistant to high concentration gentaroicin.The susceptibility of Enterococcus faecalis to all the antibiotics except for chloramphenicol and tetracycline was higher than that of Enterococcus faecium.Enterococcus faecium isolates showed a high resistant prevalence to most of antibiotics except glycopeptides and linezolid.The prevalence of PISP among 225 isolates was was 36.6%(15/41),and the prevalence of PNSSP from the other patients ranged from 15.4% to 26.6%.The susceptible rates of PSSP to cefprozil,cefuroxime and cefaclor were 67.5%(114/169),66.3%(112/169) and 61.5%(104/169),respectively.All the PISP isolates were resistant to the above three antibiotics.Teicoplanin,vancomycin and linezolid were the most active agents against Staphylococcus pneumoniae(susceptible rate,100%).About 96.9%,97.8% and 98.2% Staphylococcus pneumoniae isolates were susceptible to gatifloxacin,levofloxacin,and moxifloxacin,respectively.The susceptible rates of Staphylococcus pneumoniae to ceftriaxone,chloramphenicol and amoxicillin/clavulanic acid were 81.3%,77.3%,and 68.0%,respectively.The susceptibility of Staphylococci pneumoniae to macrolides,SXT and tetracycline ranged from 11.6% to 23.6%.Conclusions The prevalence of VRE is low in China.However,methicillin-resistance among Staphylococci isolates was high.The prevalence of PNNSP isolated from (≤)3 years children is higher than in the other age population.Teicoplanin,vancomycin,and linezolid remain high activity against Staphylococci,Enterococcus faecalis,Enterococcus faecium,and Staphylococcus pneumoniae.

ObjectiveTo investigate the prevalence,antibiotic characteristics as well as molecular background of community-associated methicillin-sensitive Staphylococcus aureus (CA-MRSA) from patients with skin and sofi tissue infections from 4 different hospitals in Beijing.MethodsFive hundred and one patients were enrolled from 4 hospitals prospectively.Patients with skin and soft tissue infections and no risk factors for healthcare-associated acquisition were included.Sample from the infection sites were collected for culture.Case report form was filled out for each patient.Antibiotic susceptibility test and molecular analysis was performed for each Staphylococcus aureus isolate.ResultsTotally 164 Staphylococcus aureus isolates were cultured from the patients with skin and soft tissue infections.Of them 5 isolates were CA-MRSA.These 5 CA-MRSA isolates harbored SCCmec Ⅰ, SCCmec Ⅲ, SCCmec Ⅳ,SCCmec Ⅴ and untypable,respectively.CA-MRSA was highly resistant to β-lactamase,levofloxacin,erythromycin and clindamycin,but susceptible to vancomycin,teicoplanin,linezolid,daptomycin,and trimethoprim/sulfamethoxazole.Prevalence of PVL in community-associated methicillin sensitive Staphylococcus aureus(CA-MSSA) and CA-MRSA were 41.9％ and 2/5.Other toxins expressed similarly between them.Combined with multilocus sequence typing (MLST) and spa typing,the major clones of CA-MSSA were ST398-t034,ST7-t796,ST398-t571,ST1t127,and ST188-t189,while in CA-MRSA were ST239-t037-SCCmec Ⅰ,ST239-t632-SCCmecⅢ,ST59-t437-SCCmecV,ST8-t008-SCCmecⅣ,and ST6-t701-NT.ConclusionsThe low prevalence of CA-MRSA in Beijing and complexity of the genetic background in CA-MRSA were observed.Clone spread is not found among CA-MRSAisolates.CA-MRSAexhibithigher resistancecomparedwithmethicillinsensitive Staphylococcus aureus (MSSA).Rational drug use scheme is called in the clinical practice to prevent development of high level resistance.

Objective To investigate antimicrobial resistance among gram-positive cocci in 14 teaching hospitals in China in 2011.Methods From June 2011 to December 2011,1498 consecutive and non-repetitive gram-positive cocci were collected from 14 teaching hospitals.The minimal inhibitory concentration (MIC) of antibacterial agents was determined by agar dilution method.A retrospective study was conducted on rates of resistance to antimicrobial agents.Data was compared using chi-square test.Results The prevalence of methicillin-resistant Staphylococcus aureus (MRSA) and methicillinresistant coagulase-negative Staphylococci (MRCoNS) was 43.7％ (222/508),and 85.6％ (214/250),respectively.The MRSA prevalence ranged from 20.0％ to 63.5％ in different regions.About 58.2％ (82/141) of Staphylococcus aureus from respiratory tract specimens,44.8％ (48/107) of Staphylococcus aureus from blood samples,and 23.8％ (31/130) of Staphylococcus aureus from pus and wound were resistant to methicillin.The susceptible rates of MRSA to chloramphenicol and sulfamethoxazole-trimethoprim SXT were 94.1％ (209/222) and 83.3％ (185/222),respectively.Susceptibility to gentamycin,erythromycin,clindamycin,tetracyclines,rifampicin and quinolones were from 11.3％ to 52.3％.All Staphylococci isolates were susceptible to vancomycin,teicoplanin,linezolid and daptomycin.Five vancomycin-resistant enterococcus (VRE) strains were found in this study.All enterococcus isolates were susceptible to daptomycin(268/268),and 98.3％ (118/120) of E.faecalis and 99.3％ (147/148) of E.faecium were susceptible to linezoild.About 45.9％ (68/148) of E.faecalis and 67.5％ (81/120) of E.faecium were resistant to high concentration gentamycin.The susceptibility of E.faecalis to all the antibiotics except for chloramphenicol and tetracycline was higher than that of E.faecium.The prevalence of penicillinnonsusceptible Streptococcus pneumoniae (PNSSP) was 15.5％ (37/239).The prevalence of PNSSP in children below 3 years-old was 25％ (13/52),and the prevalence of PNSSP from other patients was 13％(24/187).About 91.6％ (219/239),88.7％ (212/239) and 88.3％ (211/239) of S.pneumonia was resistant to erythromycin,clindamycin and tetracyclines.All S.pneumoniae strains were susceptible to teicoplanin,vancomycin,linezolid,tigecycline and daptomycin.Penicillin still showed high activity against Streptococcus spp.β-hemolytic group.More than 60％ of Streptococcus.spp.β-hemolytic group are resistant to erythromycin,clindamycin and tetracyclines.Conclusions Based on regions,the resistance rates of Gram-positive cocci are different,of which,the increasing tendency should be taken seriously.Teicoplanin,vancomycin,linezolid,tigecycline and daptomycin show very high activity against Gram-positive cocci.

Objective Toinvestigateantimicrobialresistanceamonggram-positivecocciinChinain 2013.Methods Retrospectivestudy.FromJune2013toDecember2013,1663consecutiveandnon-repetitive gram-positive cocci were collected from 15 teaching hospitals. The minimal inhibitory concentration ( MIC) of antibacterial agents was determined by agar dilution method. A retrospective study was conducted on rates of resistance to antimicrobial agents. The prevalence of penicillin-resistant Streptococcus pneumoniae ( PRSP) between children and adult patients and the prevalence of methicillin-resistant Staphylococcus aureus (MRSA) between elder group and younger adult patients were compared using chi-square test. Results The prevalence of PRSP in children below 3 years old ( 72. 9%, 51/70 ) was higher than adult patients (55. 2%, 106/192) (χ2 =6. 653,P<0. 05). About 94. 9%(261/275) and (92. 7%,255/275) of S. pneumonia were resistant to erythromycin and clindamycin. All S. pneumoniae strains were susceptible to teicoplanin, vancomycin, linezolid, tigecycline and daptomycin. Penicillin still showed very high activity against Streptococcus spp. β-Hemolytic group. More than 60% of Streptococcus spp.β-Hemolytic group were resistant to erythromycin, clindamycin and tetracyclines. The prevalence of MRSA and methicillin-resistant coagulase-negative Staphylococci(MRCoNS) was 39. 7%(229/576) and 80. 6%(224/278), respectively. The MRSA prevalence ranged from 24. 2% to 70. 0% in different regions. About 52. 6%( 100/190 ) of Staphylococcus aureus from respiratory tract specimens, 38. 5%(40/104)of Staphylococcus aureus from blood samples, and 29. 7%(58/195) of Staphylococcus aureus from wound and pus were resistant to methicillin. The prevalence of MRSA in elder group ( 48. 6%, 84/173 ) was higher than that in younger adult patients (35. 7%, 144/403)(χ2 =8. 322,P <0. 05). The susceptibility rates of MRSA to chloramphenicol and trimethoprim/sulfamethoxazole were 86. 4% ( 244/228 ) and 94. 7% ( 237/228 ) , respectively. Susceptibility rates to gentamycin, erythromycin, clindamycin, tetracyclines, rifampicin and quinolones were ranged from 15. 8% to 59. 6%. All Staphylococci isolates were susceptible to teicoplanin, vancomycin, linezolid, daptomycin and tigecycline. All Enterococcus isolates were susceptible to daptomycin and tigecycline. All E. faecalis ( 158/158 ) and 96. 4% ( 133/138 ) of E. faecium were susceptible to teicoplanin. About 98. 0% ( 150/153 ) of E. faecalis and 97. 1% ( 145/138 ) of E. faecium were susceptible to linezoild. About 45. 8% (70/153) of E. faecalis and 60. 9% (84/138) of E. faecium were resistant to gentamycin with a high concentration. The susceptibility of E. faecalis to all the antibiotics tested exceptchloramphenicolandtetracyclinewashigherthanthatofE.faecium.Conclusions Basedon different age groups and regions, the resistance rates of Gram-positive cocci are different. Teicoplanin, vancomycin, tigecycline, daptomycin, linezolid and tedizolid showed very high activity against Gram-positive cocci. (Chin J Lab Med,2015,38:373-381)

Objective To retrospectively analyze the injury characteristics of victims and treatment strategies in the explosion accident on the 17th May 2018 in Xixia county (Xixia "May 17th" explosion accident). Methods Based on the practice featured in pre-hospital emergency of Henan province and Nanyang city Emergency Center in the explosion accident, a retrospective analysis for the Level Three medical rescue was conducted, where a total of thirteen survived victims in Xixia "May 17" explosion accident were studied retrospectively. The data included the gender, age, burned extent and depth of the patients, burns complicated by trauma, complication of burn, respiratory function maintenance, resuscitation during shock stage, skin grafting with excision and scab. Furthermore, the data of organ function and the effect of the 90-day comprehensive treatment for the burned victims wereanalyzed. Results completion the Level Three treatment on time, which was depended on the leading role played by the regional trauma centers was the main rescuing mode of the work in Xixia county, where the primary and secondary treatments were the key parts. The three-level treatment model includes: the local hospital acts as a level-one emergency medical institution, county hospitals function as secondary emergency medical institutions, and other higher medical institutions are the tertiary first aid medical institutions. The pre-hospital and in-hospital emergency procedures were initiated immediately after the large-scale explosive burn being identified, the key to the successfully rescue was to set up a comprehensive treatment team for burns and trauma. Rescue team should involve burn department and other related departments, including the departments of emergency, general surgery, orthopedic, thoracic surgery, neurosurgery, plastic surgery, intensive care unit, blood transfusion unit, anesthesiology, and interventional radiology, etc. All the thirteen burned patients were male, with inhalation injury, blast injury, hemopneumothorax, brain injury, bone fractures, and etc. Eight of them (61.54%) had multiple organ dysfunction syndrome (MODS). MODS mainly involved respiratory, circulatory, liver, gastrointestinal tract, kidney and coagulation function. With the multi-discipline treatment, the wound of 6 severely-burned patients started healing and can be discharged after keeping the patency of airway, applying resuscitation fluid and comprehensive treatments such as debridement and dressing change. Among 7 patients with extensive deep burns, one case with skull-based fracture, open craniocerebral, extensive intracranial hemorrhage and hemopneumothorax, died 9 hours later. Another case died within 24 hours after injury due to obvious exudation on the site of early incision and relaxation of wound. The escharotomy, micro-dermis and allograft skin transplantation were carried out for five cases with extensive deep burns from the 4th day after the recovery of shock. One week later, the second stage of microsphere skin transplantation was performed. But all died of sepsis or fungal infection. Conclusions MODS and infection often occur during the course especially for patients with extensive and deep burns due to the great explosion in Xixia county, most of whom were accompanied with MODS and infection. Therefore, assembling multi-discipline team for treating the group of explosively-burned patients can increase the survival rate and reduce the possibility of disability.

Objective To evaluate the performance of modified Hodge test on the detection of carbapenemases among Enterobacteriaceae with decreased susceptibility to carbapenems. Methods Fortynine Enterobacteriaceae isolates with decreased susceptibility to carbapenems ( MIC of imipenem, meropenem or ertapenem was ≥ 2 μg/ml ) were collected from 16 teaching hospitals from 2004 to 2008. MICs of imipenem, meropenem and etapenem were determined by agar dilution method. Carbapenemases were detected by modified Hodge test. Carbepenemase-causing positive results and AmpCs-causing positive results were differentiated by phenyl boronic acid and oxacillin. Beta-lactamases encoding genes including blaNDM-1were detected by PCR and sequencing. Results Thirty-six of 49 isolates were non-susceptible to imipenem (MIC >4 μg/ml), 31 were non-susceptible to meropenem (MIC > 4 μg/ml) and 47 were non-susceptible to ertapenem (MIC > 2 μg/ml). Twenty-three isolates showed positive modified Hodge test result, including 9 weak-positive results and 14 strong-positive results. Through PCR detection and sequencing, 2 out of 9 isolates showing weak-positive results carried blaKPC-2 and other 7 did not carry any carbapenemase genes but AmpCs/ESBLs genes. Among the 14 isolates showing strong-positive results, 4 carried blaKPC-2, 8 carried blaIMP-4 and 2 caried blaIMP-8. All 26 isolates with negative modified Hodge test result didn't carry any carbapenemase genes. No isolate carried blaNDM-1. Carbapenemases genes PCR detection was regarded as a gold standard, and the sensitivity, specificity, positive predictive value and negative predictive value of modified hodge test was 100%, 79%, 70% and 100% on the detection of carbapenemases among Enterobacteriaceae with decreased susceptibility to carbapenems. Conclusions Modified Hodge test revealed great sensitivity but showed a few false positive results. True and false positive results can be effectively differentiated by phynel boronic acid and oxacillin.

Objective To investigate distribution and antimicrobial resistance among nosocomial pathogens from 13 teaching hospitals in China in 2009. Methods Non-repetitive pathogens from nosocomial BSI, HAP and IAI were collected and sent to the central lab for MIC determination by agar dilution method.WHONET5.6 software was used to analyze the data. Results A total of 2 502 clinical isolates were collected. The top three pathogens of BSI were Escherichia coli [27. 1% (285/1 052 )] , coagulase-negutive staphylococcus [12. 6% ( 133/1 052)] and Klebsiella pneumoniae [10. 8% ( 114/1 052)]. The top three pathogens of HAP were Acinetobacter baumannii [28. 8% (226/785)], Pseudomonas aeruginosa [16. 1% (126/785)] and Klebsiella pneumoniae [14.6% (115/785 )] . The top three pathogens of IAI were Escherichia coli[31.0% ( 206/665 )], Klebsiella pneumonia [11.3% ( 75/665 )] and Enterococcus faecium [10. 8% (72/665)]. Against Escherichia coil and Klebsiella spp. , the antimicrobial agents with higher than 80% susceptibility rate included imipenem and meropenem (98. 1%-100% ), tigecycline (95.3%-100% ), piperacillin-tazobactam ( 88.6% -97. 1% ) and amikacin ( 88. 3% -92. 5% ). Against Enterobacter spp. , Citrobacter spp. and Serratia spp. , the susceptibility rates of tigecycline were 93.5% -100% whereas the value of imipenem and meropenem were 92.9% -100%. Other antimicrobial agents with high activity included amikacin ( 85.2% -96. 7% ), pipcracillin-tazobactam ( 82.4% -96.4% ), cefepime ( 79. 6% -96. 7% ) and cefoperazonc-sulbactam (78. 7%-90. 0% ). Polymyxin B showed the highest susceptibility rateagainst Pseudomonas aeruginosa ( 100% ), followed by amikacin ( 81.9% ) and piperacillin-tazobactam (80.1% ). Polymyxin B also showed the highest susceptibility rate against Acinetobacter baumannii (98. 8% ), followed by tigecycline (90. 1% ) and minocycline (72. 0% ). The incidence of carbapenemresistant Acinetobacter baumannii was 60. 1%. The MRSA rate was 60. 2% and the MRSCoN rate was 84. 2%. All Staphylococcus strains were susceptible to tigecycline, vancomycin, teicoplanin and linezolid except for one isolate of Staphylococcus haemolysis with intermediate to teicoplanin. Two Enterococcus faecalis isolates which were intermediate to linezolid and one Enterococcus faecium isolate which was resistant to vancomycin and teicoplanin was found in this surveillance, while the MICs of tigecycline against these three isolates were 0. 032-0. 064 μg/ml. Conclusions Tigecycline, carbapenems, piperacillin-tazobactam,amikacin and cefepime remain relatively high activity against nosocomial Enterobacteriaceae. Pseudomonas aeruginosa exhibite high susceptibility to polymyxin B, while Acinetobacter baumanni shows high susceptibility to polymyxin B and tigecycline. Tigecycline, vancomycin, teicoplanin and linezolid remain high activity against nosocomial gram-positive cocci.