Epidemiological investigation and logistic regression analysis of nosocomial fungal infection in severe sepsis patients / 中国医师杂志

Objective To investigate the epidemiological characteristics of nosocomial fungal infections in severe sepsis patients and analyze the influencing factors by logistic regression.Methods The clinical data of 578 patients with severe sepsis admitted to our hospital from January 2008 to January 2016 were retrospectively analyzed.The epidemiological characteristics were investigated.The possible influencing factors of nosocomial fungal infection were analyzed by univariate analysis and multivariate logistic regression analysis.Results Among 578 cases of severe sepsis,215 cases were accompanied by nosocomial fungal infection (infection rate 37.20％).The infection sites were mostly lungs and the fungal types were Candida albicans.The prognosis of the patients was poor.The survival time was less than 90 days,accounting for 42.33％ (91/215).There were significant differences in age,length of stay in intensive care unit (ICU),duration of more than two antibiotics,use of ventilators,hormones,invasive procedures,acute physiology and chronic health evaluation Ⅱ (APACHE Ⅱ) score between the infected group and the uninfected group (P ＜ 0.05).The danger degree from high to low of the risk factors were ICU stay ≥ 100 h (OR =5.697),use respirator (OR =5.388),invasive operation (OR =4.987),age ≥65 years (OR =4.584),and continuous use of two antibiotics ＞ 7 d (OR =3.287),use steroid (OR =2.141).Conclusions Severe sepsis with hospital acquired fungal infection is more common in the lung,and most of them are Candida albicans infection,with poor prognosis and high mortality.ICU stay ≥ 100 h,use respirator and steroid,invasive operation,age ≥65 years,and continuous use of two antibiotics ＞ 7d are risk factors.Specific preventive measures should be taken to reduce fungal infections.

Antimicrobial resistance surveillance of gram-positive cocci isolated from 15 teaching hospitals in China in 2013 / 中华检验医学杂志

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)

Antimicrobial susceptibility of Gram-negative bacteria causing intra-abdominal infections in China: SMART China 2011 / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The Study for Monitoring Antimicrobial Resistance Trends program monitors the activity of antibiotics against aerobic and facultative Gram-negative bacilli (GNBs) from intra-abdominal infections (IAIs) in patients worldwide.</p><p><b>METHODS</b>In 2011, 1 929 aerobic and facultative GNBs from 21 hospitals in 16 cities in China were collected. All isolates were tested using a panel of 12 antimicrobial agents, and susceptibility was determined following the Clinical Laboratory Standards Institute guidelines.</p><p><b>RESULTS</b>Among the Gram-negative pathogens causing IAIs, Escherichia coli (47.3%) was the most commonly isolated, followed by Klebsiella pneumoniae (17.2%), Pseudomonas aeruginosa (10.1%), and Acinetobacter baumannii (8.3%). Enterobacteriaceae comprised 78.8% (1521/1929) of the total isolates. Among the antimicrobial agents tested, ertapenem and imipenem were the most active agents against Enterobacteriaceae, with susceptibility rates of 95.1% and 94.4%, followed by amikacin (93.9%) and piperacillin/tazobactam (87.7%). Susceptibility rates of ceftriaxone, cefotaxime, ceftazidime, and cefepime against Enterobacteriaceae were 38.3%, 38.3%, 61.1%, and 50.8%, respectively. The leastactive agent against Enterobacteriaceae was ampicillin/sulbactam (25.9%). The extended-spectrum β-lactamase (ESBL) rates among E. coli, K. pneumoniae, Klebsiella oxytoca, and Proteus mirabilis were 68.8%, 38.1%, 41.2%, and 57.7%, respectively.</p><p><b>CONCLUSIONS</b>Enterobacteriaceae were the major pathogens causing IAIs, and the most active agents against the study isolates (including those producing ESBLs) were ertapenem, imipenem, and amikacin. Including the carbapenems, most agents exhibited reduced susceptibility against ESBL-positive and multidrug-resistant isolates.</p>

Building CPI Mode for Teaching Chinese as a Foreign Language:Orientation towards Strengthening Intercultural Communication Competence in a TCM University / 浙江中医药大学学报

[Aim]To create CPI mode of teaching Chinese as a foreign language in a TCM university. [Method]Based on conventional teaching, language partner and interculture communication class(mixing Chinese and international students) were introduced in CPI mode. The effect of this mode was ana-lyzed. [Result] By effectively promoting the cooperative learning between Chinese and international students, CPI mode could not only improve Chinese teaching effect, but also improve international students’ability on intercultural communication.[Conclusion] Based on its practice, CPI mode is believed as an effective way to improve teaching and study.

Antimicrobial resistance surveillance of gram-positive cocci isolated from 14 hospitals in China in 2011 / 中华检验医学杂志

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.

Clinical microbiology laboratory should pay attention to the changes in CLSI document M100 / 中华检验医学杂志

Recent major changes and updates of Clinical and Laboratory Standards Institute(CLSI) document M100 for performance standards for antimicrobial susceptibility testing were introduced in the article,which include changes of interpretive criteria and comments,antimicrobial susceptibility testing of infrequently isolated or fastidious bacteria,changes of appendixes and others,Brief comments were made for these changes.

Epidemiological investigation of community-acquired methicillin resistant Staphylococcus aureus infection from 4 hospitals in Beijing / 中华检验医学杂志

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.

Report from Chinese Meropenem Susceptibility Surveillance in 2010 : antimicrobial resistance among nosocomial gram-negative bacilli / 中华检验医学杂志

Objective To investigate antimicrobial resistance among gram-negative bacilli in China in 2010.Methods A total of 1 259 consecutive and non-repetitive gram-negative bacilli were isolated from 13 teaching hospitals from September to December in 2010 in China.All of these isolates were sent to the central laboratory for re-identification and susceptibility testing.The MIC of meropenem and other antibacterial agents were determined by agar dilution method.Interpretive results was determined by CLSI M100-S21.Results The activity of 14 antibacterial agents against 845 Enterobacteriaceae isolates was as follows in order:meropenem ( 98.1％,829 ),amikacin ( 94.0％,794 ),imipeuem ( 90.0％,761 ),piperacillin/tazobactam ( 87.5％,739 ),cefepime ( 83.0％,701 ),ertapenem ( 82.4％,696 ),cefoperazone/sulbactam ( 80.3％,678 ),colistin (75.4％,637),ceftazidime (70.0％,591 ),ciprofloxacin (59.1％,499 ),cefoxitin ( 54.8％,463 ),ceftriaxone ( 53.5％,452 ),cefotaxime ( 52.3％,442 ) and minocycline(51.5％,435).The prevalence of ESBL was 61.3％ (106/173) in Escherichia coli,which was much higher than 41.2％ (70/170) in Klebsiella pneumoniae.The susceptibility rate of Klebsiella pneumoniae against meropenem,imipenem,amikacin and colistin were more than 90％,but were highly resistant to ceftriaxone and cefotaxime.Over 80％ of Enterobacter cloacae,Enterobacter aerogenes,Citrobacter freundii,were susceptible to meropenem,amikacin,cefepine,cefoperazone/sulbactam,imipenem,piperacillin/ tazobactam,and ertapenem.The most active antibiotics against Pseudomonas aeruginosa were Colistin (98.4％,182),Amikacin ( 85.9％,159 ),Piperacillin/Tazobactam ( 80％,148 ),Ceftazidime ( 79.5％,147),Meropenem (74.1％,137),Ciprofloxacin (74.1％,137),Cefepime (73.5％,136),Imipenem (71.9％,132) and Cefoperazone/Sulbactam (70.8％,131 ).Less than 37％ of Acinetobacter baumannii isolates were resistant to carbapenems.The susceptible rate to Minocycline was 47.8％.Colistin kept good activity against Acinetobacter baumannii (susceptible rate,97.8％,n =176),The prevalence of Pan-drug resistant P.aeruginosa and A.baumannii was 18.9％ (n =35),and 61.8％ (n =108),respectively.Conclusions Carbapenems remained very high activity against Enterobacteriaceae.Increasing resistance to the antimicrobials agents test among A.baumanni and P.aeruginosa,especially carbapenems among A.baumanni brought great concern.

Antimicrobial resistance surveillance study among Streptococcus pneumoniae clinically isolated from 14 teaching hospitals in 2005-2008 in China / 中华检验医学杂志

Objective To investigate antimicrobial resistance among Streptococcus pneumoniae clinically isolated from 14 teaching hospitals located at different areas in China in 2005-2008 and to give logical guidance for clinical empirical therapy.Methods A total of 1 317 non-repetitive S.pneumoniae isolates in 14 teaching hospitals from 2005-2008 were collected and sent to the central lab for reidentification and susceptibility testing, including 271 isolates collected in 2005, 391 isolates collected in 2006, 363 isolates collected in 2007 and 292 isolates collected in 2008. Most of the isolates were from community-acquired respiratory tract infections, which were isolated from outpatient or emergency department patients with respiratory tract infections or those patients with respiratory tract infections within ≤48 hours hospitalization.The districts where the organisms were isolated include North China, Northeast China, South China, Central and Northwest China and East China.The patients included adults, teenagers and children.The minimum inhibitory concentrations (MICs) or inhibitory zone diameter of 17 antimicrobial agents were determined by Etest method, agar dilution method or disk diffusion method.WHONET5.5 software was used to analyze susceptibility rate, intermediate rate, resistance rate, MIC50 and MIC90.Results Linezolid (100%) and fluoroquinolones (95.2%-99.7%) showed excellent activities against S.pneumoniae.Among β-lactams, amoxicillin-clavulanic acid remained high activities (73.8%-92.1%),followed by penicillin, ceftriaxone and cefepime with year-over-year decrease in activities.The activities of three second-generation cephalosporins were low (36.3%-38.4% in 2008).The activities of erythromycin, azithromycin, clindamycin, trimethoprim/sulfamethoxazole and tetracycline against S.pneumoniae were poor and decreased year over year.The incidence of penicillin non-susceptible S.pneumoniae (PNSP) was increasing especially for PISP (from 4.4% in 2005 to 20.2% in 2008).The incidence of PNSP in North China was low (6.0%), while this value were high in central China and East China (30.1% and 38.7%, separately).The incidence of PNSP in adults (15.7%) was obviously lower than that in children(≤5 years:33.0%) and teenagers (6-17 years:38.2%).Conclusions linezolid and fluoroquinolones showed excellent in vitro activity against S.pneumoniae, followed by penicillin and cephalosporins with year-over-year decrease of activity. Clinicians should pay more attention when using those antimicrobial agents with poor activity against S.pneumoniae, which include macrolides, clindamycin, trimethoprim/sulfamethoxazole and tetracycline.

Analysis of antimicrobial resistant mechanisms and genetic homogeny of Salmonella from community acquired infections in Shenzhen / 中华检验医学杂志

Objective To investigate the antimicrobial resistance mechanisms and genetic homogeny of Salmonella from community acquired infections in Shenzhen,China.Methods Ninety-three of Salmonella were isolated from 2002 to 2007 at Shenzhen People's Hospital,China.PCR and DNA sequencing were used to investigate the mutation in QRDR of the gyrA,gyrB,parC and parE.Plasmid mediated quinolone resistance genes including qnr and aac(6')-Ib-cr,β-lactamase genes including blaTEM,blaSHV,blaOXA, blaCTX-M, and class 1 integron were detected. All isolates were typed by PFGE. Results S. enterica typhi and S. enterica paratyphi A were susceptible to ampicillin, chloramphenicol, trimethoprim/sulfamethoxazole, ceftriaxone and ciprofloxacin, with the susceptible rate of 96%-100%. Fifty-two percent (13/25) of S. enterica typhi and 95% (61/64) of S. enterica paratyphi A were resistant to nalidixic acid. Twenty-four percent (6/25) of nalidixic acid-resistant S. enterica typhi and 94% (60/64) of nalidixic acid-resistant S. enterica paratyphi A showed decreased susceptibility to ciprofloxacin (MIC of 0. 125-1 μg/ml).All nalidixic acid-resistant (susceptible to ciprofloxacin ) Salmonella (NARS) isolates had a single substitution in the QRDR of GyrA, and 91% (68/75) of these isolates carried the substitution Ser83Phe in GyrA. Two mutations in the QRDR of GyrA were detected in both of two ciprnfloxacin-resistant Salmonella,with the additional one mutation in the QRDR of parC. Plasmid mediated quinolone resistance genes including qnr and aac(6')-lb-cr were not detected in any isolate. The blaCTX-M-14 gene was detected in a ceftriaxoneresistant isolate of S. enterica paratyphi A, with ISEcpl located on the upstream of it. Three muhidrugresistant strains of Salmonella all carried one 1 900 bp classⅠ integron gene cassette dhfrⅫ-orfF-aadA2,with the additional one β-lactamase gene of blaTEM-1, or blaOXA-30. Twenty-two distinct PFGE patterns were observed among twenty-five S. enterica typhi. The PFGE patterns of sixty-four S. enterica paratyphi A showed limited genetic diversity (average similarity of 91% ). Ninety investigated inpatients were infected in the community. Six patients infected by S. enterica paratyphi A had a travel history before infection. Conclusions Nalidixic acid-resistant S. enterica typhi and S. enterica paratyphi A are highly prevalent in Shenzhen,China. The mutation in the QRDR of GyrA is the prevalent mechanism responsible for the resistance to nalidixic acid in Slmonella. The great genetic similarity among S. enterica paratyphi A isolates indicates endemic disease from the presence of a single clone over 6-year period.

Antimicrobial resistance surveillance among nosocomial pathogens in 13 teaching hospitals in China in 2009 / 中华检验医学杂志

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.

Antimicrobial resistance surveillance of gram-positive cocci isolated from 12 teaching hospitals in China in 2008 / 中华检验医学杂志

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.

An antimicrobial resistance surveillance of gram-positive cocci isolated from 12 teaching hospitals in China in 2009 / 中华内科杂志

Objective To investigate antimicrobial resistance among gram-positive cocci in China in 2009. Methods From June to December 2009, 1169 consecutive and non-repetitive gram-positive cocci were collected from 12 teaching hospitals at 9 cities. The minimal inhibitory concentration (MIC) of antibacterial agents was determined by agar dilution method. Results The prevalences of methicillinresistant Staphylococcus aureus (MRSA) and methicillin-resistant coagulase-negative Staphylococci (MRCoNS) were 45.3% (211/466) and 89. 5% (214/239), respectively. The isolation rate of MRSA was 33. 3%-68. 1% from different samples. All Staphylococci isolates were susceptible to vacomycin, teicoplanin and linezolid. Five point five percent (7/128) E. faecium strains were resistant to vacomycin. All E.faecalis strains were susceptible to vacomycin. About 99. 1% (108/109) of E. faecalis and E. faecium were susceptible to linezoild. The prevalence of penicillin-intermediate Streptococcus pneumoniae (PISP) was 21.6% (48/222). Only 1 (0. 5%, 1/222) Streptococcus pneumoniae strain was resistant to penicillin.Teicoplanin, vancomycin, linezolid and tigecycline were the most active agents against Streptococcus pneumoniae (susceptible rate 100% ). Conclusions The high prevalence of methicillin-resistance is among Staphylococcus strains. Different samples show a different MRSA prevalence. Teicoplanin, vancomycin and linezolid show very high activity to Staphylococci,E. faecalis, E. faecium and Streptococcus pneumoniae.

Performance of modified Hodge test on the detection of carbapenemase among Enterobacteriaceae / 中华检验医学杂志

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.

Evaluation of the value of an automatic bacteria identification system and blaOXA-51-like gene amplification in the identification of acinetobacter species / 中华检验医学杂志

Objective To evaluate the value of automatic bacteria identification systems including Phoenix and Vitek2 Compact, as well as blaOXA-51-like gene amplification in the identification of Acinetobacter species compared with amplified ribosomal DNA restriction analysis(ARDRA). Methods A total of 50 non-repeated clinical isolates of Acinetobacter species were collected in PUMCH from 2006 to 2007 and identified by ARDRA, blaOXA-51-like gene amplification, Phoenix and Vitek2 Compact,respectively. Results Compared with ARDRA, the sensitivity and specificity of blaOXA-51-like gene amplification were both 100%. The accuracy rates of Phoenix and Vitek2 Compact were 44% and 56%, respectively. Conclusions The accuracy of phenotypic identification of Acinetobacter species is not ideal, however, blOXA-51-like gene amplification could be used as a fast and reliable method for identification of A. baumannii. ARDRA is recommended in the study of drug resistant mechanisms and homological analysis of Acinetobacter species.

Standardization of antibiotic susceptibility test and reasonable test consulting / 中华检验医学杂志

In this article standard antibiotic susceptibility test methods and key terms in reporting results recommended by the Clinical and Laboratory Standards Institute (CLSI) were introduced into nine parts: (1) Key points in routine antibiotic susceptibility test. (2) Staphylococcus spp. (3) Enterococcus spp. (4) Streptococcus pneumoniae. (5) Streptococcus spp. other than Streptococcus pneumoniae. (6) Infrequently isolated strains or fastidious bacteria. (7) Enterobacteriaceae. (8) Pseudomonas aeruginosa and other non-Enterobacteriaceae. (9)Haemophilus influenzae and H. parainfluenzae. The author also introduced part of updated contents from CLSI M100-S19,2009.

The microbiology laboratory should intensively cooperate with the clinicians to improve the diagnostic level of pulmonary infections / 中华检验医学杂志

The diagnosis with unknown pathogens is an important cause of inappropriate use of antimicrobial agents. The microbiology laboratory should intensively cooperate with the clinicians to evaluate the quality of respiratory tract samples. The technicians of microbiology should strengthen the training for basic skills, such as direct smear and a variety of staining. Meanwhile, the laboratory should perform the rapid detection techniques to improve the diagnostic level of pulmonary infections.

In vitro activity of cefminox and comparators against Escherichia coli, Klebsiella pneumoniae and Bacteroides species / 中华检验医学杂志

Objective To compare the in vitro activity of cefminox with other antimicrobial agents against clinical Escherichia coil, Klebsiella pneumoniae isolates and Bacteroides species. Methods MICs of sixteen antimicrobial agents against 945 Escherichia coli and 588 Klebsiella pneumoniae isolates from 15 teaching hospitals and MICs of four antimicrobial agents against 50 Bacteroides species isolates were determined by agar dilution method. WHONET 5.4 software was used to analyze the data. Results Among 1533 Escherichia coli and Klebsiella pneumoniae isolates, 628 isolates produced neither extended-spectrum beta-lactamases (ESBLs) nor AmpC, while 837 isolates produced only ESBLs and 68 isolates produced AmpC enzymes. The susceptibility rate of cefminox against non-ESBLs-producing or ESBLs-producing isolates was above 90%. MIC_(50) of eefminox was 2-4 fold lower than cefometazole and 8-16 fold lower than cefoxitin. MIC50 of cefminox was 2-8 fold lower than cefometazole and 8-16 fold lower than cefoxitin. Against ESBLs-producing isolates, the in vitro activity of cefminox was superior to the third and fourth generation cephalosporins, aztreonam, cefoperazone/sulbactam, levofloxacin, amikacin and inferior to carbapenems. Its activity was similar to piperacillin-tazobactam. The susceptibility rate of cefminox against AmpC-producing isolates was less than 20%. The susceptibility rate of cefminox against Bacteroides species was 90%, which was higher than that of cefometazole (50% -70%) and penicillin (0%) and similar to that of metronidazole. Conclusion Cefminox exhibites good activity against ESBLs-producing and non-ESBLs-producing Escherichia coli and Klebsiella pneumoniae isolates and Bacteroides species, which indicates that cefminox could be one of the options for the treatment of infections caused by these organisms.

The molecular characteristics of heteroresistant vancomycin-intermediate Staphylococcus aureus in China / 中华检验医学杂志

Obiective To investigate the molecular characteristics of heteroresistant vancomycinintermediate Staphylococcus aureus(hVISA)in China and analyze the differences of the molecular characteristics between hVISA and VSSA(vancomycin-susceptible Staphylococcus aureus)isolates.Methods A total of 3 15 non-repetitive MBSA were collected from the national surveillance program in China in 2007.The isolates of hVISA were confirmed by modified population analysis profile-area under the curve(PAP-AUC).The genotypes of agr and SCCmec were determined by multiplex PCR,and spa typing was performed bv PCR and DNA sequencing.The pvl gene was detected bv PCR Results The prevalence of hVISA was 9.5%(30/315).Among 315 MRSA,SCCmec Ⅲ was the most popular type,which was found in 234 isolates(234/315,74.3%),followed by SCCmec Ⅱ,which was identified in 56 isolates (56/315,17.8%).The rate of SCCmec Ⅱ in hVISA(46.7%)was significantly hisher than in VSSA (14.7%,X~2=18.93,P＜0.001).The most prevalent agr type among 315 MRSA was agr 1 accounting for 73.6%(232/315).The agr 2 accounted for 18.7%(59/315),and agr 3 and agr 4 were very rare in clinical isolates.It was different in agr types between the two groups.The rate of agr 2 in hVISA(53.4%)was higher than in VSSA(15.1%).X~2 value was 26.08 and P value was less than 0.001 through X~2 test.There was a statistical significance in the result.There were 4 spa types in hVISA isolates,including t002 (13 isolates),t037(9 isolates),t030(6 isolates),and 1548(2 isolates).The pvl positive MRSA isolates were very low,accounting for 1.6%(5/315).Conclusions The prevalence of hVISA was relatively higher in China.Compared to VSSA,the majority(53.4%)of the hVISA strains were agr 2,which was obviously different from VSSA.hVISA isolates were more diverse by spa typing,

In vitro activity of daptomycin and other antimicrobial agents against 499 strains of gram-positive cocci causing bloodstream infection / 中华内科杂志

Objective To evaluate the in vitro activity of daptomycin, vancomycin, teicoplanin, tigecycline, ceftobiprole and linezolid against 499 strains of blood-isolated gram-positive cocci. Methods Determination of the minimal inhibitory concentration (MICs) of daptomycin with microbrothdilution method and the MICs of other 9 antimicrnhial agents with agar dilution method against 499 strains of blood-isolated gram positive cocci was carried out. The data was analyzed with WHONET 5.4 software. Results The susceptibility rates of staphylococci to daptomycin, tigecycline, linezolid, ceftobiprole, vancomyein and teicoplanin were 100%. All staphylococcus strains were inhibited by daptomycin at a MIC of 1 mg/L. The MIC50 and MIC60 of daptomyein were both 0.5 mg/L against methicillin-resistant Staphylococcus aureus (MRSA) and methicillin-resistant Staphylococcus coagalase-negative (MRSCnN). Among Enterococcus spp, the highest MIC of daptomycin was 4 mg/L. The MIC50 and MIC90 of daptomycin were both 2 mg/L against E.faecalis, whereas they were 2 mg/L and 4 mg/L against E.faecium. One strains of linezolid-resistant E.faecalis(MIC:8 mg/L)was susceptible to daptomycin (MIC: 1 mg/L). Three strains of E.faecium carrying vanA gene with vancomycin MICs above 32 mg/L and teicoplanin MICs also 32 mg/L were susceptible to daptomycin, tigeeycline and linezolid. The MIC range of daptomycin against Streptococcus pneumoniae and Streptococcus viridans was 0.032-0.25 mg/L and 0.125-1.000 mg/L separately. Conclusions Daptomycin has excellent in vitro activity against common gram-positive pathogens isolated from blood. It may be a good choice for clinicians to treat drug-resistant gram-positive cocci.