1.Role of WAVE1 in drug resistance of K562/A02 leukemia cells.
Rui KANG ; Li-zhi CAO ; Yan YU ; Ting HU ; Zhuo WANG ; Wang-qiong XU ; Min XIE
Chinese Journal of Hematology 2007;28(6):379-382
OBJECTIVETo investigate if WAVE1 is involved in mult drug-resistance (MDR) of human leukemia cell line K562/A02.
METHODSThe level of WAVE1 in K562 and K562/A02 cells was assayed by Western blot and RT-PCR; K562 cells and K562/A02 cells were transient transfected with pEFBOS-WAVE1 reconstructed plasmid or specifically siRNA to WAVE1. 50% inhibition concentration (IC50) of doxorubicin on K562/A02 was determined by WST-8 assay. Hoechst33258 staining was used to examine cell morphological changes and to calculate percentage of apoptotic nuclei. The mRNA level of mdrl was assayed by RT-PCR. The Bcl-2 protein was assayed by Western blot.
RESULTS1. The WAVE1 expression at mRNA and protein level in K562/A02 cells was increased by about 70% and 63% respectively as compared with that in K562 cells. 2. Overexpression of WAVE1 in K562 cells by transient transfection significantly increased the resistance to doxorubicin, and increased IC50 from (0.05 +/- 0.00) microg/ml to (2.99 +/- 0.12) microg/ml, and at 1 microg/ml or 5 microg/ml of doxorubicin treatment, cell apoptotic nuclei rate was decreased by 30% or 35% respectively. 3. Suppression of WAVE1 in K562/A02 cells by siRNA resulted in a reversal of MDR to doxorubicin, and decreased IC50 from (4.29 +/- 0.15) microg/ml to (1.85 +/- 0.07) microg/ml, and at 1 microg/ml or 5 microg/ml of doxorubicin treatment, cell apoptotic nuclei rate was increased by 24% or 21% respectively. 4. Overexpression of WAVE1 in K562 cells significantly increased the mdrl mRNA and the Bcl-2 protein, and suppression of WAVE1 in K562/A02 cells by siRNA decreased the mRNA and the protein.
CONCLUSIONWAVE1 involves in the MDR mechanisms in K562/A02 leukemia cells through regulation the level of mdrl and Bcl-2.
Apoptosis ; Drug Resistance, Multiple ; Drug Resistance, Neoplasm ; Genetic Vectors ; Humans ; K562 Cells ; Plasmids ; genetics ; RNA Interference ; RNA, Messenger ; genetics ; Transfection ; Wiskott-Aldrich Syndrome Protein Family ; genetics ; metabolism
2.Antimicrobial resistance surveillance of gram-positive cocci isolated from 7 teaching hospitals in China in 2006
Hongli SUN ; Hui WANG ; Minjun CHEN ; Ziyong SUN ; Yunsong YU ; Bijie HU ; Yunzhuo CHU ; Jiansheng ZHUO ; Kang LIAO ; Yingchun XU ; Xiuli XIE
Chinese Journal of Laboratory Medicine 2008;31(6):635-642
Objective To investigate antimicrobial resistance among gram-positive cocci in China in 2006.Methods From Jun 2006 to Dec 2006,674 consecutive and non-repetitive gram-positive bacteria were collected from 7 teaching hospitals.The minimal inhibitory concentration(MICs)of antibacterial agents were determined by agar dilution method.Results The prevalence of penicillin.resistant(ease)and pemcllhn. intermediate S.pneumoniae(PISP)among 100 isolates was l%and 19%,respectively.Teicoplanin and vancomycin were the most active agents against S.pneumoniae.97% and 98% S.pneumoniae isolates were susceptible to levofloxacin and moxifloxacin,respectively.The susceptibility of amoxicillin/clavulanic acid, ceftriaxone and chloramphenicol are 96%,87% and 73%,respectively.The susceptible rates of penicillin. susceptible S.pneumoniae(PSSP)to cefprozil and cefaclor were 62% and 55.7%,respectively.All the PISP and PRSP isolates were resistance to the two antibiotics.The susceptibility to macrolides,trimethoprim/ sulfamethoxazole and tetracycline was lower than 35%.The prevalence of methicillin-resistant Staphylococcus aureus(MRSA)and methicillin.resistant coagulase-negative Staphylococci(MRSCON)was 48%(33%-84%)and 81%(69%-94%),respectively.The susceptible rates of MRSA to trimethoprim/ sulfamethoxazole,chloramphenicol,rifampin,and the other antibiotics in this study were 72%,66%and 45%,respectively.The susceptible rate of MRSA to marcrolides,aminoglycosides,tetracyclines and quinolones were not more than 18%.56%(30%-86%)of E.faecalis and 80%(50%.100%)of E.faecium were highly resistant to gentamicin.The susceptibility of E.faecalis to all the antibiotics except chloramphenicol and tetracycline were higher than E.faecium.All isolates of S.aureus,CoNS and E.faecalis tested were susceptible to vacomycin and teicoplanin.There were two vacomycin.resistant E.faecium strains isolated from Hangzhou.Conclusions Antimicrobial resistance patterns of gram.positive cocci differed in different regions.The resistance of gram-positive cocci to the antibiotics in this study this year was a little higher than the data of the year of 2005.Teicoplanin and vancomycin remained very high activity to gram-positive cocci.
3.Expression of WAVE1 in childhood acute lymphocytic leukemia and in the apoptosis of Jurkat cells induced by adriamycin.
Zhuo WANG ; Ting HU ; Li-Zhi CAO ; Rui KANG ; Ming-Yi ZHAO ; Yan YU ; Wang-Qiong XU
Chinese Journal of Contemporary Pediatrics 2008;10(5):620-624
OBJECTIVETo investigate whether WASP/Verprolin homologous protein 1 (WAVE1) plays a role in the pathogenesis of childhood acute lymphoblastic leukemia (ALL).
METHODSWAVE1 mRNA and protein expression in bone marrow mononuclear cells (BMMCs) was measured by RT-PCR and Western blotting respectively in 4 children with ALL relapse, 15 children with ALL in complete remission (CR) and 40 children with newly diagnosed ALL. Ten normal bone marrow samples were used as controls. Jurkat cells were treated with different concentrations of adriamycin (ADM). The cell proliferation was detected with MTT. The apoptosis rate was measured by flow cytometry. WAVE1 mRNA and protein expression of Jurkat cells treated with ADM was detected by RT-PCR and Western blotting respectively.
RESULTSWAVE1 was not expressed or weakly expressed in BMMCs from normal controls and patients with ALL in CR. Higher WAVE1 mRNA and protein expression was found in BMMCs from patients with newly diagnosed ALL and patients with relapse ALL when compared with the controls and the patients in CR (P<0.01). ADM significantly inhibited the proliferation of the Jurkat cells and the inhibitory effect was dose-and time-dependent (P<0.05). After ADM treatment for 24 hrs, the percentage of apoptosis cells increased significantly and WAVE1 mRNA and protein expression of Jurkat cells decreased significantly when compared with the untreated controls (P<0.05).
CONCLUSIONSThe WAVE1 expression increased in children with ALL. WAVE1 may be related to the development of ALL and may be severed as a marker for the evaluation of the severity of ALL in children.
Adolescent ; Antibiotics, Antineoplastic ; pharmacology ; Apoptosis ; drug effects ; Blotting, Western ; Cell Proliferation ; drug effects ; Child ; Child, Preschool ; Doxorubicin ; pharmacology ; Female ; Humans ; Infant ; Jurkat Cells ; Male ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; etiology ; metabolism ; RNA, Messenger ; analysis ; Wiskott-Aldrich Syndrome Protein Family ; analysis ; genetics ; physiology
4.Analysis of pathogen spectrum and antimicrobial resistance of clinical common organisms from twelve teaching hospitals in 2016
He′nan LI ; Ji ZENG ; Yan JIN ; Zhidong HU ; Kang LIAO ; Yanping LUO ; Chao ZHUO ; Rong ZHANG ; Xiuli XU ; Wenen LIU ; Yingmei LIU ; Yunzhuo CHU ; Hui WANG
Chinese Journal of Laboratory Medicine 2018;41(9):651-657
Objective To investigate the spectrum and antimicrobial resistance of major pathogens causing nosocomial infections in China, 2016. Methods Non-duplicated nosocomial cases as well as pathogens causing bloodstream infections ( BSI) , hospital-acquired pneumonia ( HAP) and intra-abdominal infections ( IAI ) from 12 teaching hospitals across China were collected. The minimum inhibitory concentrations (MICs) of important clinical common strains were determined by agar dilution method or broth microdilution method. The CLSI M100-S27 criteria was used for interpretation. Data were analyzed by using WHONET-5. 6 software. Results A total of 2060 cases were collected, including 894 cases from BSI, 630 cases from HAP and 536 cases from IAI. The MICs of 1896 important clinical common strains were determined. Escherichia coli and Klebsiella pneumoniae were the most prevalent pathogens causing BSI and IAI, while Acinetobacter baumanii and Pseudomonas aeruginosa were dominated in HAP. All Staphylococcus aureus were susceptible to tigecycline, linezolid, daptomycin and glycopeptides. Methicillin-resistant S. aureus accounted for 44. 4% ( 75/169 ) of all the S. aureus. The rate of methicillin-resistant coagulase-negative staphylococci was 80. 9% ( 72/89 ) . No Enterococcus strains were found resistant to tigecycline, linezolid or daptomycin. Vacomycin resistant enterococcus was found in Enterococcus faecium, accounting for 1. 8% ( 2/111 ) of all E. faecium strains. Tigecycline, meropenem, amikacin, imipenem, and polymyxin B exhibited high potency against Enterobacteriaceae and the susceptibility rates were 96. 6%(865/895), 94. 3% (859/911), 94. 2% (858/911), 94. 1% (857/911), and 91. 6% (820/895), respectively. The prevalence of extended-spectrum β-lactamase was 58. 4% ( 263/450 ) in E. coli and 28. 6% ( 84/294 ) in K. pneumonia. The rate of carbapenem resistant K. pneumonia and E. coli was 15. 3% ( 45/294 ) and 1. 8% ( 8/450 ) , respectively. The percentage of polymyxin B resistant K. pneumonia and E. coli was 4. 1% ( 12/294 ) and 4. 4% ( 20/450 ) , respectively. The rate of tigecycline resistant K. pneumonia and E. coli was 2. 4% ( 7/294 ) and 0. 2% ( 1/450 ) , respectively. A. baumanii showed low susceptibility to the antimicrobial agents except tigecycline ( 91. 4%, 235/257 ) and polymyxin B (100%, 257/257). The rate of carbapenem resistant A. baumanii was 80. 5% (207/257). The rate of carbapenem resistant P. aeruginosa was 31. 7% ( 59/186 ) . Polymyxin B and amikacin demonstrated high antibacterial activity against P. aeruginosa with susceptility rate of 100% ( 186/186 ) and 90. 9% ( 169/186), respectively. Conclusions Nosocomial pathogens showed high susceptibilities against tigecycline and polymyxin B. Antimicrobial resistance in A. baumannii is a serious problem. The prevalence of carbapenem-resistant Enterobacteriaceae and polymyxin B resistant Enterobacteriaceae has increased, which should be monitored continuously in China.
5.The effects of pravastatin on platelet-derived nitric oxide system in rabbits.
Li-ping MA ; Ma-fei KANG ; Song-mei YIN ; Da-nian NIE ; Shuang-feng XIE ; Yu-Dan WU ; Yi-qing LI ; Jian-hong FENG ; Li-zhuo XU
Chinese Journal of Hematology 2005;26(9):539-542
OBJECTIVETo observe the effects of pravastatin on platelet-derived nitric oxide system in hypercholesterolemia (HC) and atherosclerosis (AS) in rabbits, and the relationship between these changes and atherosclerosis courses.
METHODSThirty male New Zealand white rabbits were randomly divided into three groups, 12 in group A, 12 in group B, and 6 in group C. All of them were fed daily with cholesterol-rich food during the first 12 weeks. In addition, in group A, pravastatin (10 mg) was orally administered daily. At the end of the 12th week, 6 in group A and B were killed randomly and their aortas were removed and the pathologic changes were observed. In the following 12 weeks, food enriched with cholesterol was substituted with normal food in all three groups. Pravastatin treatment was continued or started in the remaining members of group A and group B, but not in group C. At the end 24th week, all rabbits were killed and their aortas were examined for the fatty-streaks or atherosclerotic plaques. The expressions of endothelial NOS (eNOS) mRNA and inducible NOS (iNOS ) mRNA, NOS activity, NO production and the level of the serum lipids were measured at 0, 6th, 12th, 18th and 24th week.
RESULTSThe expression levels of platelet-derived NOS mRNA, eNOS mRNA ratio in group A had no difference at above time points, while in group B were reduced significantly at 6th week and 12th week compared with at 0 week (P <0.01), and increased at 18th week and 24th week compared with 12th week (P <0.05). The expression levels of eNOS mRNA in group C were reduced at 6th, 12th and 18th, 24th week compared with 0 week (P <0.05 and P <0.01, respectively), and were reduced in groups B and C compared with group A at 6th ,12th week (P < 0.05) and increased in group A and B compared with group C at 18th, 24th week (P <0.01). The expression levels of iNOS/mRNA among the three groups had no difference. Pathologic finding of the arteries: AS was not found in group A from the 12th to 24th week. While in group B, there were a lot of fatty-streaks on the entire intima of all large arteries at the 12th week. There were also fatty-streaks in the ascending aorta, but were improved at the 24th week. In group C, there were marked plaques in the entire aorta at the 24th week.
CONCLUSIONSThe expressions of platelet-derived eNOS mRNA, NOS activity, NO production are decreased in HC or AS rabbits. Pravastatin can up-regulate expressions of platelet-derived eNOS mRNA, NOS activity, leading to preventing or improving the pathological courses of AS.
Animals ; Atherosclerosis ; blood ; pathology ; Blood Platelets ; metabolism ; Disease Models, Animal ; Male ; Nitric Oxide ; blood ; genetics ; Nitric Oxide Synthase ; blood ; genetics ; Pravastatin ; pharmacology ; RNA, Messenger ; genetics ; Rabbits
6.Clinical Observation on Peiyuan Yangxin Acupuncture and Moxibustion Method Combined with Gubu Pills in the Treatment of Type 2 Diabetes Mellitus Complicated with Osteoporosis
Zi-Jun HAO ; Jin-Xiong LAO ; Chao-Yi WANG ; Zhuo-Kang XU
Journal of Guangzhou University of Traditional Chinese Medicine 2024;41(9):2374-2380
Objective To observe the clinical effect of Peiyuan Yangxin(cultivating vital essence and nourishing heart)acupuncture and moxibustion method combined with Gubu Pills in the treatment of type 2 diabetes mellitus complicated with osteoporosis(T2DOP).Methods A total of 70 patients with T2DOP were randomly divided into treatment group and control group,with 35 cases in each group.The control group was treated with conventional hypoglycemic and calcium supplementation.On the basis of the control group,the treatment group was treated with Peiyuan Yangxin acupuncture and moxibustion method combined with Gubu Pills for eight weeks.After two months of treatment,the clinical efficacy of the two groups was evaluated,and the changes of serum osteocalcin(OC),total type 1 collagen amino acid extension peptide(PINP),β-collagen special sequence(β-CTX),inorganic phosphorus(P)and glycosylated hemoglobin(HbA1c)were observed before and after treatment.The changes of pain Visual Analogue Scale(VAS),Hamilton anxiety scale(HAMA)and diabetes specific quality of life scale(DSQL)scores were compared before and after treatment between the two groups.The safety and adverse reactions of the two groups were evaluated,and the recurrence rate and rehospitalization rate of the two groups were counted.Results(1)After treatment,the serum OC,PINP,β-CTX and P levels of patients in the two groups were significantly improved(P<0.05),and the observation group was significantly superior to the control group in improving serum OC,PINP,β-CTX and P levels,with a statistically significant difference(P<0.05).(2)After treatment,the HbA1c level of patients in both groups was significantly improved(P<0.05),and the treatment group was significantly superior to the control group in improving HbA1c level,with statistically significant differences(P<0.05).(3)After treatment,the VAS,HAMA and DSQL scores of patients in the two groups were significantly improved(P<0.05),and the treatment group was significantly superior to the control group in improving VAS,HAMA and DSQL scores,with statistically significant differences(P<0.05).(4)The total effective rate was 88.57%(31/35)in the treatment group and 68.57%(24/35)in the control group.The efficacy of the treatment group was superior to that of the control group,and the difference was statistically significant(P<0.05).(5)The recurrence in the treatment group was significantly less than that in the control group,and the difference was statistically significant(P<0.05).(6)There were no statistically significant differences of the incidence of adverse reactions between the two groups of patients(P>0.05).Conclusion Peiyuan Yangxin acupuncture and moxibustion method combined with Gubu Pills in the treatment of T2DOP can significantly reduce the pain and anxiety symptoms of patients,improve the biochemical indexes of bone metabolism,thereby improving the quality of life of patients,increasing the effective rate of treatment,and reducing the recurrence rate and the rate of rehospitalization in the short term.
7.Distribution and resistance surveillance of common pathogens of nosocomial infections in 10 teaching hospitals in China from 2020 to 2021
Shuguang LI ; Binghuai LU ; Yunzhuo CHU ; Rong ZHANG ; Ji ZENG ; Danhong SU ; Chao ZHUO ; Yan JIN ; Xiuli XU ; Kang LIAO ; Zhidong HU ; Hui WANG
Chinese Journal of Laboratory Medicine 2024;47(6):619-628
Objective:To investigate the spectrum and antimicrobial resistance of major pathogens causing nosocomial infections in China during 2020-2021.Methods:A total of 1 311 non-duplicated nosocomial pathogens causing bloodstream infections (BSI, n=670), hospital-acquired pneumonia (HAP, n=394) and intra-abdominal infections (IAI, n=297) were collected from 10 teaching hospitals across China. The minimum inhibitory concentrations (MICs) of clinical common strains were determined using agar dilution or broth microdilution method. Interpretation of reults followed the CLSI M100-Ed33 criteria, with data analysis conducted using WHONET-5.6 software. The Chi-square test was used to compare rates. Results:The most prevalent pathogens causing BSI were Escherichia coli (21.2%, 142/670), Klebsiella pneumoniae (14.9%, 100/670) and Staphylococcus aureus (11.5%, 77/670); the most prevalent pathogens causing HAP were K. pneumoniae (27.7%, 109/394), Acinetobacter baumanii (22.1%, 87/394) and Pseudomonas aeruginosa (18.3%, 72/394). IN IAI, E. coli (24.3%, 60/247), Enterococcus faecium and K. pneumoniae (both 14.6%, 36/247) were dominated. All S. aureus strains were susceptible to tigecycline, linezolid, daptomycin and glycopeptides. Rates of methicillin-resistant S. aureus (MRSA) and coagulase-negative Staphylococcus (MRCNS) were 36.5% (42/115) and 74.5% (38/51), respectively. The rate of vancomycin-resistant E. faecium and E. faecalis was 3.3% (3/90) and 1.9% (1/53), respectively. The prevalence of extended-spectrum β-lactamase (ESBL) was 23.7% (58/245) in K. pneumonia and 60.5% (130/215) in E. coli.The rate of carbapenem-resistant K. pneumonia and E. coli was 29.8% (73/245) and 4.2% (9/215), respectively; the percentage of tigecycline-resistant K. pneumonia and E. coli was 1.6% (4/245) and 0, respectively; the rate of colistin-resistant K. pneumonia and E. coli was 1.6% (4/245) and 2.8% (6/215), respectively; the percentage of ceftazidime/avibactam-resistant K. pneumonia and E. coli was 2.0% (5/245) and 2.3% (5/215), respectively. The rate of carbapenem-resistant A. baumanii and P. aeruginosa was 76.7% (125/163) and 28.4% (33/116), respectively. A. baumanii showed low susceptibility to most antimicrobial agents except colistin (98.8%, 161/163) and tigecycline (89.6%, 146/163). Colistin, amikacin and ceftazidime/avibactam demonstrated high antibacterial activity against P. aeruginosa with susceptility rates of 99.1% (115/116), 94.0% (109/116) and 83.6% (97/116), respectively. Conclusions:The major pathogens of nosocomial infections were K. pneumonia, E. coli, A. baumanii, P. aeruginosa and S. aureus. Nosocomial Gram-negative pathogens exhibited high susceptibilities to tigecycline, colistin and ceftazidime/avibactam. Antimicrobial resistance in A. baumannii remains a significant challenge. The increasing prevalence of carbapenem-resistant Enterobacterales underscores the urgency of antibiotics rational applications and hospital infection controls.
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.Performance of modified Hodge test on the detection of carbapenemase among Enterobacteriaceae
Qiwen YANG ; Rui ZHENG ; Hui WANG ; Minjun CHEN ; Yingchun XU ; Weiyuan WU ; Yunsong YU ; Ziyong SUN ; Mingqing TONG ; Rong ZHANG ; Kang LIAO ; Bin CAO ; Xinhong HUANG ; Lianna ZHU ; Yuxing NI ; Ping JI ; Chao ZHUO ; Danhong SU ; Hong FAN ; Wenen LIU ; Xiuli XU ; Hongli SUN ; Xiuli XIE
Chinese Journal of Laboratory Medicine 2010;33(12):1122-1127
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.
10.CHINET 2014 surveillance of bacterial resistance in China
Fupin HU ; Demei ZHU ; Fu WANG ; Xiaofei JIANG ; Yingchun XU ; Xiaojiang ZHANG ; Zhaoxia ZHANG ; Ping JI ; Yi XIE ; Mei KANG ; Chuanqing WANG ; Aimin WANG ; Yuanhong XU ; Jilu SHEN ; Ziyong SUN ; Zhongju CHEN ; Jingyong SUN ; Sufei TIAN ; Jin LI ; Hong ZHANG ; Jing KONG ; Yunjian HU ; Xiaoman AI ; Chao ZHUO ; Danhong SU
Chinese Journal of Infection and Chemotherapy 2015;(5):401-410
Objective To investigate the susceptibility and resistance of clinical isolates from hospitals in several regions of China .Methods Fifteen general hospitals and two children′s hospitals were involved in this program . Antimicrobial susceptibility testing was carried out according to a unified protocol using Kirby‐Bauer method or automated systems .Results were analyzed according to CLSI 2014 breakpoints .Results A total of 78 955 clinical isolates were collected from January to December 2014 ,of which gram negative organisms and gram positive cocci accounted for 72 .6% and 27 .4% ,respectively . Methicillin‐resistant strains in S .aureus(MRSA)and coagulase negative Staphylococcus(MRCNS)accounted for an average of 44 .6% and 83 .0 % ,respectively .The resistance rates of methicillin‐resistant strains to β‐lactams and other antimicrobial agents were much higher than those of methicillin‐susceptible strains .However ,92 .0% of MRSA strains were still susceptible to trimethoprim‐sulfamethoxazole ,while 85 .6% of MRCNS strains were susceptible to rifampin .No staphylococcal strains were found resistant to vancomycin ,teicoplanin or linezolid .In Enterococcus spp .,the resistance rates of E .f aecalis strains to most tested drugs (except chloramphenicol) were much lower than those of E . f aecium .Some strains of both species were resistant to vancomycin .Vancomycin resistant strains of E . f aecalis and E . f aecium were mainly V anA ,V anB or V anM type based on their phenotype or genotype .Regarding non‐meningitis S .pneumoniae strains ,the prevalence of penicillin‐susceptible S .pneumoniae strains isolated from both adults and children were higher than those isolated in 2013 ,but the prevalence of penicillin‐intermediate S . pneumoniae or penicillin‐resistant S . pneumoniae strains decreased . The prevalence of ESBLs producingstrainswas55.8% in E.coliand29.9% in Klebsiellaspp.(K.pneumoniaeand K.oxytoca)and24.0% in Proteus mirabilis isolates on average . ESBLs‐producing Enterobacteriaceae strains were more resistant than non‐ESBLs‐producing strains in terms of antibiotic resistance rates . The strains of Enterobacteriaceae were still highly susceptible to carbapenems .Overall less than 10 % of these strains were resistant to carbapenems . About 62 .4% and 66 .7% of Acinetobacter spp .(A .baumannii accounts for 93 .0 % ) strains were resistant to imipenem and meropenem ,respectively . Compared with the data of year 2013 ,extensively‐drug resistant strains in K . pneumoniae and A .baumannii increased . Conclusions The antibiotic resistance of clinical bacterial isolates is growing .The disseminated multi‐drug or pan‐drug resistant strains in a special region poses a serious threat to clinical practice and implies the importance of strengthening infection control .