1.Bone grafting and internal fixation for treating fibrous dysplasia of the adult proximal femur A 13.case report
Zhongzhi YUAN ; Chenfeng TANG ; Guoxin LI ; Jian WEN ; Gang LIU ; Yunzhuo YANG ; Jiyun LI
Chinese Journal of Tissue Engineering Research 2009;13(30):5985-5990
The present study retrospectively analyzed 13 patients with fibrous dysplasia of the adult proximal femur who received treatment at the Department of Orthopedics,Shenzhen Hospital,Peking University between March 2000 and June 2006.These patients comprised 6 males and 7 females,with an age of 21-35 years.Among 11 patients suffering from mild hip pain,6 presented with mild limping due to worsened pains,and 2 exhibited obvious manifestations of bone fracture.All patients underwent X-ray,CT examinations,and 3 were subjected to MRI examinations,prior to bone grafting and internal fixation.Monostotic lesion was observed in 10 patients and polystotic lesion in 3 patients,but endocrine disturbance was not observed in any patient.Nine patients suffered from lesions in the femoral neck and 4 from lesions in the femoral rotator.Curettage,autogenous and allogeneic bone grafting,and internal fixation with dynamic hip screws and proximal femoral nails were successfully performed in each patient.Internal fixation time averaged 165 minutes (range 120-210 minutes).During the early stage after surgery,weight-bearing activities were not permitted.Bone fracture healed after an average of 3 months.Eighteen to forty-eight months of follow-up demonstrated that clinical symptoms were relieved,with good hip joint function and basically normal gait.X-ray plains showed thickened cortical bone,as well as compacted ossification shadow in bone grafting region.In addition,partial bone absorption,but not recurrent clinically,was observed in 4 patients.These findings imply that thorough curettage,autogenous and allogeneic bone grafting,and internal fixation with dynamic hip screws and proximal femoral nails is a reliable method to treat fibrous dysplasia of the adult proximal femur and it can acquire satisfactory curative effects.
2.Experiment study on stress relaxation and creep of spinal lumbar vertebrae (T12-L5) by simulating operations of excising lumbar disc intervertebrales by the front route and by the back route.
Yunzhuo YANG ; Jianing HE ; Hongshun MA
Journal of Biomedical Engineering 2002;19(3):398-401
We have studied the characteristics of stress relaxation and creep on lumbar vertebrae(T12-T5) of 18 fresh corpses. We measured the stress relaxation and creep of the normal group(intact spine), the control group 1(simulating the operations by the front route) and the control group 2(simulating the operations by the back route). Then we obtained the stress, strain-time curves and data under the conditions of constant stress and strain. By using regression analysis we obtained the reduced stress relaxation and creep functions. Finally, We analyzed and discussed the effects of the operations of excising the disc intervertebrales by the front route and the back route.
Diskectomy
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methods
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Elasticity
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Humans
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Lumbar Vertebrae
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physiology
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surgery
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Male
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Relaxation
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Stress, Mechanical
3.Antimicrobial resistance surveillance of gram-positive cocci isolated from 14 hospitals in China in 2011
Yu GUO ; Hui WANG ; Chunjiang ZHAO ; Zhanwei WANG ; Feifei ZHANG ; Bin CAO ; Bijie HU ; Kang LIAO ; Yaning MEI ; Qing YANG ; Yingchun XU ; Minjun CHEN ; Zhidong HU ; Ziyong SUN ; Liyan ZHANG ; Yunsong YU ; Yunzhuo CHU ; Xiuli XU ; Yuxing NI
Chinese Journal of Laboratory Medicine 2012;(11):1021-1028
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.
4.Antimicrobial resistance of gram-negative bacilli isolated from 14 teaching hospitals across China in 2016
Qi WANG ; Ping JI ; Xiuli XU ; Yingchun XU ; Ziyong SUN ; Zhidong HU ; Yunsong YU ; Bin YANG ; Kang LIAO ; Juan LU ; Yunzhuo CHU ; Yaning MEI ; Lizhong HAN ; Xianju FENG ; Hui WANG
Chinese Journal of Laboratory Medicine 2017;40(8):614-622
Objective To investigate antimicrobial resistance among nosocomial gram-negative bacilli in 2016 across China.Methods About 1 394 consecutive and non-repetitive gram-negative bacilli were isolated from 14 teaching hospitals from March to August in 2016 across China.All of these isolates were sent to the central laboratory for reidentification and susceptibility testing.The minimal inhibitory concentration(MICs)of meropenem and other antibacterial agents were determined by agar dilution method.The data were analyzed by using WHONET-5.6 software.Results The activity of antimicrobial agents against Enterobacteriaceae was as follows in descending order of susceptible rate: meropenem (95.2%,891/936), amikacin (94.6%,885/936), ertapenem (92.1%,862/936), piperacillin/tazobactam (88.1%,825/936), imipenem (88.0%,823/936), cefoperazone-sulbactam (83.1%,778/936), cefepime (72.2%,676/936), cefiazidime (72.2%,676/936), levofloxacin(68.8%,644/936), ciprofloxacin (63.2%,592/936), minocyline (62.9%,589/936), cefiriaxone (54.9%,514/936), cefotaxime (54.0%,505/936), cefoxitin (44.3%,415/936).The sensitivities of E.coli to carbapenems, amikacin, piperacillin-tazobactam, polymyxin B and cefoperazone-sulbactam were over 80%.The more sensitive antibiotic to Klebsiella pneumoniae was polymyxin B (99.0%), followed by amikacin (84.9%), meropenem (84.4%) and imipenem (82.0%).The prevalence of extended-spectrum β-lactamase was 62.8%(137/218)in Escherichia coli and 28.3%(58/205)in Klebsiella pneumonia.The activity of antimicrobial agents against E.cloacae, E.aerogenes and Citrobacter freundii was as follows in descending order of susceptible rate: meropenem (97.0%-98.5%), amikacin (95.8%-98.3%), imipenem (94.5%-97.5%), polymyxin B (96.4%-100%), cefoperazone-sulbactam (76.5%-90.0%), ertapenem (73.3%-90.1%), piperacillin/tazobactam (82.4%-88.3%).The most active agents against Pseudomonas aeruginosa were polymyxinB (100%), followed by amikacin (89.3%) and ciprofloxacin (82.4%).The most active agents against Acinetobacter baumannii were polymyxinB (100%).The sensitivities of Acinetobacter baumannii to meropenem, imipenem, minocycline and cefoperazone-sulbactam were 20.3%(39/202), 19.3%(41/202), 66.3%(134/202) and 24.8%(50/202), respectively.Conclusions Carbapenems remain high sensitive against Enterobacteriaceae.Controlling carbapenem resistant Klebsiella pneumoniae is urgent.Drug antimicrobial resistance in A.baumanni is a still serious problem.
5.Antimicrobial resistance surveillance of gram-positive cocci isolated from 15 teaching hospitals in China in 2013
Yu GUO ; Hui WANG ; Chunjiang ZHAO ; Feifei ZHANG ; Zhanwei WANG ; Bin CAO ; Yingchun XU ; Minjun CHEN ; Bijie HU ; Yuxing NI ; Liyan ZHANG ; Kang LIAO ; Qing YANG ; Yunsong YU ; Xiuli XU ; Yunzhuo CHU ; Zhidong HU ; Ziyong SUN ; Yaning MEI ; Zhiyong LIU
Chinese Journal of Laboratory Medicine 2015;(6):373-381
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)
6.A-485 alleviates tubular lipid accumulation by inhibiting H3K18ac/H3K27ac induced by P300/CBP in diabetic mice
Li MENG ; Yan ZHU ; Yan YANG ; Ting WU ; Yunzhuo REN ; Linshan DU ; Shijie ZENG ; Chunyang DU
Chinese Journal of Clinical and Experimental Pathology 2024;40(5):509-514
Purpose To investigate the protective effect and mechanism of A-485 on renal tubular injury in diabetic mice.Methods Eighteen male C57BL/6J mice were randomly divided into three groups:Control group,diabetic kidney dis-ease(DKD)group and A-485 treatment group.The DKD mice model was established by feeding high-fat diet for 8 weeks and intraperitoneal injection of streptozotocin for 5 days.Subsequent-ly,the A-485 treatment group was given A-485(10 mg/kg/day)by intraperitoneal injection every other day for 4 weeks.After treatment,the renal function,P300 enzyme activity and lipid deposition in renal tissue were measured.Western blot a-nalysis was performed to detect SREBP-1,FASN,ACC,ChREBP,P300,CBP,H3K18ac and H3K27ac protein levels.Results Compared with control mice,the levels of FBG,BUN,Scr and UAE were significantly increased in diabetic mice(FBG:2.52 times,BUN:2.89 times,Scr:2.13 times,UAE:4.21 times),while diabetic mice treatment with A-485 exhibi-ted a remarkable decrease on BUN,Scr and UAE(BUN:0.511 times,Scr:0.636 times,UAE:0.574 times,P<0.01).The results of the transmission electron microscopy and oil red O stai-ning showed that A-485 treatment prevents lipid droplets forma-tion and up-regulation of SREBP-1,FASN,ACC and ChREBP in renal tubular cells of diabetic mice(SREBP-1:0.544 times,FASN:0.449 times,ACC:0.306 times,ChREBP:0.317 times,P<0.01).Furthermore,A-485 intervention downregu-lated the enzyme activity of P300(0.546 times)and suppressed the expression of H3K18ac(0.337 times)and H3K27ac(0.308 times,P<0.01).Conclusion A-485 can significant-ly improve renal lipid metabolic disorder in diabetic mice,which may be achieved by inhibiting p300-induced H3K18ac and H3K27ac.
7.Analysis of bacterial resistance monitoring results in a tertiary hospital in Shenyang in 2022
Lijie GUO ; Shuhuan YANG ; Fushun LI ; Jingjing CHEN ; Qihui WANG ; Yunzhuo CHU
Journal of China Medical University 2024;53(5):458-463
Objective To analyze pathogen distribution and drug resistance in a tertiary hospital in Shenyang in 2022 and provide evi-dence-based guidance for this and other hospitals to formulate antibacterial drug application strategies.Methods In 2022,bacterial iso-lates collected from patients in a tertiary hospital in Shenyang were identified and subjected to drug sensitivity tests based on the require-ments of the national clinical laboratory operation procedures.The data were analyzed using Whonet 5.6 software.Results In total,4968 pathogenic strains were isolated from this hospital in 2022.The top five isolates were Escherichia coli,Klebsiella pneumoniae,Acineto-bacter baumannii,Enterococcus faecalis,and Pseudomonas aeruginosa.The resistance rates of Escherichia coliand Klebsiella pneumo-niaeto carbapenems were 1.9%and 17.7%,respectively.The resistance rates of Enterobacter cloacaeto imipenem and meropenem were 26.7%and 25.0%,respectively.The isolation rate of methicillin-resistant Staphylococcus aureus(MRSA)was 15.6%.The resistance rates of vancomycin-resistant Enterococcusand linezolid-resistant Enterococcus faecaliswere 7.1%and 11.6%,respectively.The resist-ance rates of tropical yeasts to fluconazole was>20%.Conclusion The distribution and drug resistance of pathogens in this hospital differed from those in other regions of China.The drug resistance of strains in this hospital should be closely monitored to understand the distribution and drug resistance of pathogens in a timely manner and to provide guidance for the diagnosis and treatment of infections.
8.Antimicrobial resistance surveillance among nosocomial pathogens in 13 teaching hospitals in China in 2009
Qiwen YANG ; Hui WANG ; Yingchun XU ; Minjun CHEN ; Danhong SU ; Zhidong HU ; Kang LIAO ; Ji ZENG ; Yong WANG ; Bin CAO ; Yunzhuo CHU ; Rong ZHANG ; Wenen LIU ; Chunmei ZHOU ; Yongzhong NING ; Xiuli XU ; Chao ZHUO ; Bin TIAN ; Dongmei CHEN ; Yan XIONG ; Ping LI ; Yingmei LIU ; Hua NIAN ; Lihong LI ; Mingxiang ZOU ; Hongmei XIE ; Peihong YANG ; Hongli SUN ; Xiuli XIE
Chinese Journal of Laboratory Medicine 2011;34(5):422-430
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.
9.Antimicrobial susceptibility surveillance in China: a MOHNARIN program report (2009-2010)
Yun LI ; Yuan LU ; Feng XUE ; Jian LIU ; Bo ZHENG ; Xiuzhen ZHANG ; Yunjian HU ; Ting YU ; Yunzhuo CHU ; Zhidong HU ; Jianhong ZHAO ; Shiyang PAN ; Wangsheng ZHAO ; Bijie HU ; Qiulian DENG ; Jian YANG ; Yan LI ; Wenen LIU ; Ling ZHOU ; Fang DONG ; Weiling FU ; Xiuli XU ; Fengyan PEI ; Ling MENG ; Ping JI ; Manning LI ; Weiwei YANG ; Jia ZHANG
Chinese Journal of Laboratory Medicine 2012;35(1):67-87
Objective To investigate the bacterial resistance in nationwide and understand the distribution of bacterial and resistance trend.MethodsThe 6507 clinical isolates were collected from 19 hospitals in 17 cities.The susceptibility tests were performed using agar dilution method recommended by Clinical and Laboratory Standards Institute (CLSI) in central laboratory.The values of MIC50,MIC90 and MICrange were calculated by SPSS 17.0 and the susceptibilities of isolates to antimicrobial agents were determined by using CLSI (2010) guideline.Of all 6507 isolates,4691 strains were collected from target wards and 1816 were isolated from others wards.ResultsAmong 4691 strains,1156 were Gram-positive (24.6% ) and 3535 were Gram-negative (75.4%).Based on the minimum inhibitory concentration results,the prevalence of methicillin resistant Stapylococcus aureus and methicillin resistant Stapylococcus epidermidis are 51.6% ( 325/630 ) and 87.0% ( 228/262 ) respectively.Staphylococci showing intermediate or full resistance to vancomycin were not observed. Coagulase negative Staphylococci showed 2.5% (16/642)intermediate rate and 1.6% ( 10/642 ) full resistance rate to teicoplanin,and showed 0.5% ( 3/642 )resistance rate to linezolid.Antibiotic resistance rate of Enterococcus faecalis to ampicillin was 17.1%(19/111),while the resistance rate of Enterococcus faecium to ampicillin reached up to 85.0%(164/193).Three Enterococcus faecium were resistant to glycopeptides.The prevalence of penicillin resistance Streptococcus pneumoniae and penicillin intermediate Streptococcus pneumoniae were 41.2% ( 145/352) and 37.2% (131/352) respectively based on oral penicillin criterion,while the prevalence were 0.0% (0/352) and 6.0%(21/352) based on vein to non-meningitis criterion.A vast majority of Enterobacteriaceae maintained high susceptibility to carbapenems,with resistance rate less than 2.0%.In addition,tigecycline,moxalactam,fosfomycin and amikacin displayed desirable antibacterial activity against Enterbacteriaceae,and resistance rates to these drugs were all less than 10.0%.For non-fermenting Gramnegative isolates,resistance rate of Pseudomonas aeruginosa and Acinetobacter baumannii to imipenem were 23.1% ( 139/601 ) and 53.5% (419/784) respectively.Resistance rate of Acinetobacter baumannii was much higher than that during the period 2007 - 2008.Colistin,tigecycline,minocycline and fosfomycin demonstrated good antibacterial activity against Acinetobacter baumannii in vitro.Conclusions Compared with MOHNARIN 2007 -2008year surveillance results, significant increase in resistance rate of Acinetobacter baumannii was demonstrated.Resistant strains to linezolid and tigecycline were found.Bacterial resistance has been a widespread problem in our country,which requires much more attention.
10.Antimicrobial resistance of gram-negative bacilli isolated from 13 teaching hospital across China in 2018
Qi WANG ; Bin YANG ; Ziyong SUN ; Yaning MEI ; Yunsong YU ; Kang LIAO ; Dawen GUO ; Xiuli XU ; Yingchun XU ; Zhidong HU ; Yunzhuo CHU ; Yi LI ; Ping JI ; Hui WANG
Chinese Journal of Laboratory Medicine 2020;43(4):416-424
Objective:To monitor the susceptibility of common used antimicrobial agents against nosocomial Gram-negative bacilli in 2018 across China.Methods:Prospective collection of Gram-negative bacilli from 13 teaching hospitals nationwide from January to December 2018. The minimal inhibitory concentration (MICs) of antibiotics such as meropenem was determined by agar dilution methods and broth microdilution methods. Interpretation of results using the Clinical and Laboratory Standards Institute(CLSI) 2019 M100S (29th Edition) standard. Data were analyzed by using WHONET-5.6 software.Results:A total of 1 214 non-repetitive Gram-negative bacilli were collected, accounting for 96.7% (1 174/1 214) of blood and sterile body fluid samples. The activity of antimicrobial agents against 871 strains of Enterobacteriaceae was as follows in descending order of susceptible rate: amikacin (93.2%, 812/871), meropenem (92.0%, 801/871), ertapenem (88.9%, 774/871), imipenem (88.4%, 770/871), piperacillin-tazobactam (84.0%, 732/871), cefoperazone-sulbactam (83.1%, 724/871), cefepime (71.4%, 622/871), minocyline (68.9%, 600/871), ceftazidime (66.9%, 583/871), levofloxacin (54.4%, 474/871).The resistance rates of Escherichia coli to the third generation cephalosporins were 61.5% (155/252) (ceftriaxone) and 60.7% (153/252) (cefotaxime), respectively. The resistance rates of Klebsiella pneumoniae to the third generation cephalosporins were 56.6% (126/222) (ceftriaxone) and 57.9% (129/222) (cefotaxime), respectively. The incidence of extended-spectrum β lactamase (ESBLs) positive E. coli and K. pneumoniae was 50.2% (127/252) and 18.2% (40/222), respectively. Over 95% of all the ESBLs positive strains were susceptible to imipenem and meropenem. The incidence of carbapenem-resistant Escherichia coli and Klebsiella pneumoniae was 2.8% (7/252) and 20.4% (45/222), respectively. For Enterobacter cloacae, Klebsiella aerogenes, Citrobacter freundii, the most susceptible agent were tigecycline (96.3%-100%), followed by amikacin (94.9%-97.1%), meropenem (89.8%-96.6%)and imipenem (89.8%-94.9%).The susceptibility of Proteus mirabilis, Morganella morganii and Serratia marcescens to meropenem and amikacin was over 90%.A total of 67 strains of carbapenems resistant enterobacteriaceae(CRE) were detected. Modified carbapenem inactivation method showed, 45 strains were serine carbapenemase and 20 were metalloenzymes. The susceptibility of Pseudomonas aeruginosa to meropenem and imipenem were 73.2% (112/153) and 66.0% (101/153), respectively. Acinobacter baumannii has the highest sensitivity to colistin (100%, 163/163), followed by tigecycline (87.1%, 142/163).Compared with other sources of infection, specimens of bloodstream infections were less resistant to Klebsiella pneumoniae (17.6%, 27/153 vs 21.7%, 15/69) and Acinetobacter baumannii (68.3%, 71/104 vs 71.2%, 42/59). Escherichia coli (2.5%,4/198 vs 0%,0/54) and Pseudomonas aeruginosa (37%, 33/89 vs 18.8%, 12/64) have a high proportion of carbapenem resistance. Conclusions:Carbapenems still maintain high antibacterial activity against Enterobacteriaceae bacteria, especially strains producing only ESBLs. Carbapenem-resistant Klebsiella pneumoniae should be given sufficient attention. Carbapenemase is the most important drug resistance mechanism of carbapenem-resistant Enterobacteriaceae in China.