Antimicrobial resistance of gram-negative bacilli isolated from 13 teaching hospital across China in 2018 / 中华检验医学杂志

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.

Cytotoxic and antibacterial polyketide-indole hybrids synthesized from indole-3-carbinol by

Two skeletally undescribed polyketide-indole hybrids (PIHs), named indolchromins A and B, were generated from indole-3-carbinol (I3C) in the fungal culture (). The indolchromin structures were elucidated mainly by their 1D and 2D NMR spectra with the former confirmed by the single-crystal X-ray crystallographic analysis. Each indolchromin alkaloid was chirally separated into four isomers, whose absolute configurations were assigned by comparing the recorded circular dichroism (CD) spectra with the electronic CD (ECD) curves computed for all optional stereoisomers. Furthermore, the indolchromin construction pathways in fungal culture were clarified through enzyme inhibition, precursor feeding experiment, and energy calculation. The cascade reactions, including decarboxylative Claisen condensation catalyzed by 8-amino-7-oxononanoate synthase (AONS), C()-H activation, double bond migration, and Michael addition, all undergone compatibly during the fungal cultivation. In an MIC range of 1.3-8.6 μmol/L, (2,4)- and (2,4)-indolchromin A and (2,4)-indolchromin B are inhibitory against , , sp., , and . (2,4)-Indolchromin A and (2,4)-indolchromin B were cytotoxic against the human breast cancer cell line MDA-MB-231 with IC values of 27.9 and 131.2 nmol/L, respectively, with the former additionally active against another human breast cancer cell line MCF-7 (IC 94.4 nmol/L).

Distribution and antibiotic resistance of 532 bacterial panthogens in blood culture in a hematology de-partment / 中华微生物学和免疫学杂志

Objective To analyze the distribution and antibiotic resistance of bacterial pathogens in blood culture in the Department of Hematology of the First Affiliated Hospital of Nanjing Medical Universi-ty from 2013 to 2017. Methods BACTEC FX automatic blood culture instrument was used for blood cul-ture. VITEK-2 Compact automatic microbial identification and drug susceptibility system was used for bacte-rial identification, drug sensitivity testing and fungal identification. K-B and ATB FUNGUS 3 methods were used for Streptococcus and fungi susceptibility testing, respectively. WHONET5. 6 software was used for sta-tistical analysis. Results The positive results of blood culture accounted for 7. 6% during 2013 to 2017 and the top five isolated pathogenic bacteria were Escherichia coli (20. 9% ), Klebsiella pneumoniae (18. 0% ), coagulase negative Staphylococcus (12. 4% ), Pseudomonas aeruginosa (11. 5% ) and Enterobacter cloacae (3. 6% ). Carbapenems (94. 4% ) were the most active antibiotics against Enterobacteriaceae. Pseudo-monas aeruginosa strains were sensitive to all antibacterial dugs except aztreonam. Acinetobacter baumannii strains had a lower sensitivity to almost all antibacterial dugs. Vancomycin, linezolid and teicoplanin were active antimicrobial agents against gram-positive cocci. Conclusion Patients with hematological diseases are more susceptible to nosocomial infection, which should be paid more attention to in clinical and laborato-ry practice. Rational antimicrobial therapy is an effective way for control of antimicrobial resistance.

Pathogen distribution and susceptibility profile of fungal isolates from bloodstream infections during the period from 2013 through 2015 / 中国感染与化疗杂志

Objective To investigate the pathogen distribution and susceptibility profile of fungal isolates from bloodstream infections,and valuate the clinical utility of G test in diagnosis of fungal infections for the purpose to improve antifungal therapy.Methods A retrospective analysis was carried out to analyze the fungal pathogens isolated from bloodstream infections in the First Affiliated Hospital of Nanjing Medical University during the period from January 2013 through December 2015 and their antimicrobial susceptibility.Results A total of 114 fungal strains were isolated from bloodstream infections during the 3-year period,most of which were Candida (99/114,86.8％),especially Candida albicans (30.7％).About 41.2％ (47/114) of the fungal strains were isolated from Department of Thoracic Surgery (10,5 and 4 strains in 2013,2014 and 2015),Hematology (11 strains in 2014),and ICU (7 strains in 2014).Antimicrobial susceptibility testing showed that all the fungal strains (100％) were susceptible to amphotericin B,but 83.5％ susceptible to itraconazole (the lowest).G test was positive before the result of blood culture in 13 of the 54 patients who received G test.Conclusions Candida was the most common fungus in fungal bloodstream infection.Amphotericin B is the most active antifungal agent in vitro.Blood culture combined with serological test can provide clinicians an earlier and reliable diagnosis.

Inhibitory and dispersive effects of betaine on formation of Staphylococcus aureus biofilm / 临床检验杂志

Objective To observe the formation of Staphylococcus aureus biofilm and the inhibitory and dispersive effects of betaine on the biofilm.Methods The inhibitory and dispersive effects of 0.1％ betaine on the biofilm from 20 strains of Staphylococcus aureus were examined by crystal violet assay.Results All the 20 strains of Staphylococcus aureus formed biofilm.The biofilm of methicillinsensitive Staphylococcus aureus (MSSA) was formed in 24 hours with peak value of absorbance (A590 nm) (1.99 ± 0.53).The biofilm of methicillin-resistant Staphylococcus atureus(MRSA) was formed in 48 hours with peak value of absorbance(A590 nm) (1.13 ±0.47).After adding betaine,the absorbance(A590 nm) of MSSA biofilm fell down to(1.74 ± 0.61) in 24 hours,while the absorbance(A590 nm) of MRSA biofilm fell down to(0.40 ± 0.12) in 48 hours,which was significantly reduced compared with the controls (t =2.43,5.84,P ＜ 0.05 respectively).When adding betaine after the biofilm formed,the absorbancies (A590 nm) of both MSSA and MRSA showed no significant difference compared with the controls (P ＞ 0.05).Conclusion Betaine could inhibit biofilm formation of Staphylococcus aureus at concentration of 0.1％,but it could not disperse the mature biofilm of Staphylococcus aureus.

Antimicrobial resistance of gram-negative bacilli isolated from 14 teaching hospitals across China in 2016 / 中华检验医学杂志

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.

Distribution and antimicrobial resistance of clinical gram-negative bacteria in the First Afifliated Hospital of Nanjing Medical University during 2014 / 中国感染与化疗杂志

Objective To investigate the distribution and antimicrobial resistance profile of clinical gram-negative bacterial isolates in the First Afifliated Hospital of Nanjing Medical University during 2014.Methods Bacteria identiifcation was performed by API system or the VITEK-2 Compact automatic identiifcation system. Disk diffusion susceptibility testing or VITEK-2 Compact automatic identification system was used to determine the susceptibility to antimicrobial agents. All data were analyzed using WHONET 5.6 software.Results Among the total 7 931 clinical isolates in 2014, gram-negative bacteria accounted for 64.2% (5 088/7 931). The top three pathogens wereE. coli,A. baumannii andK. pneumoniae. Notably, during the year 2014, 195 strains of carbapenem-resistantEnterobacteriaceaewere isolated, about 6.9% of all theEnterobacteriaceae isolates. Meanwhile, 613 (66.5%) strains of multiple drug resistantA. baumannii and 197 (28.7%) strains of multiple drug resistantP. aeruginosa were isolated.Conclusion During the year 2014, the resistance of the gram-negative bacteria in this hospital is mainly characterized by carbapenem-resistantEnterobacteriaceae, multiple drug resistant A. baumanniiand multiple drug resistantP. aeruginosa. Surveillance of antimicrobial resistance is beneifcial for rational use of antibiotics.

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 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.

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.

Epidemic Status of Acinetobacter ssp. in Lower Respiratory Tract Infection and Their Drug Resistance / 中华医院感染学杂志

OBJECTIVE To investigate the epidemic situation of Acinetobacter in lower respiratory tract infection and their drug resistance,in order to provide evidence for clinical anti-infection therapy. METHODS The data of Acinetobacter from the sputum specimens of inpatients in our hospital with lower respiratory tract infection during 2006-2007 were collected and analyzed with the software the software WHONET5.4. RESULTS Among all pathogens in lower respiratory tract infection,Acinetobacter accounted for 9.2% in 2006 and 7.4% in 2007,the rate in deparment of neurosurgery,surgical ICU and respiratory ICU was higher. Acinetobacter had the highest susceptible rate to imipenem and were also susceptible to meropenem and cefoperazone/sulbactam. However,Acinetobacter had higher resistant rate to imipenem and meropenem while higher susceptible rate to cefoperazone/sulbactam in 2007 than in 2006. The susceptible rate of Acinetobacter to the third and forth generation cephalosporins,amikacin,levofloxacin and aztreonam was lower than 50%. CONCLUSIONS The drug resistance mechanism of Acinetobacter is so complicated that many kinds of drugs prove poorly effective. Carbopenems are recommended when single drug is utilized and drug combination based on the clinical and laboratory information can be tried.

Distribution and antimicrobial resistance change of blood culture isolates from the year 2004 to 2007 / 中华检验医学杂志

n positive blood culture, and they are resistant to a variety of antimicrobial agents, which should be called attention.

The mechanism of quinolone resistance in Pseudomonas aeruginosa / 中华临床感染病杂志

Objective To investigate the mechanism of quinolone resistance in Psendomonas aeruginosa.Methods The minimum inhibitory concentrations (MICs)of ciprofloxacin and levofloxacin with and without carbonylcyainde-m-chlorophenylhydrazone(CCCP)were determined by agar dilution method.Polymerase chain reaction(PCR)and DNA sequencing were used to study the mutations in quinolone resistance-determining region of gyrA and parC genes.The strains were genotyped by enterbacterial repetitive intergenie consensus-PCR(ERIC-PCR).Results Sixteen quinolones-resistant Pseudomonas aeruginosa strains were obtained.The MICs of ciprofloxacin and levofloxacin were not reduced significantly by adding CCCP.Thr-83→Ile of gyrA and Ser-87→Leu of parC were found simultaneously in 16 strains of resistant Pseudomonas aeruginosa.Analysis of ERIC-PCR products indicated that 16 quinolone-resistant strains had an identical band pattern which was different from that seen in the sensitive strains.Conclusion Mutations in gyrA and parC may be the main mechanism of quinolone resistance in clinical isolates of Pseudomonas aeruginosa.

Application of two-round PCR in rapid molecular diagnosis of fungus-infected clinical specimens / 中华皮肤科杂志

Objective To establish a diagnosis method for fungal infection using two-round PCR,and to evaluate its sensitivity in the detection of clinical specimens suspected to be infected with fungi.Methods A total of 29 specimens of clinical sputum and alveolar wash solution were collected from patients with suspicious fungal infection.All specimens uaderwent direct microscopy with 10%KOH,fungal culture,one-round PCR and two-round PCR.The fungal universal primer targeting ITS regions of rDNA was used in PCR.The detection rate for fungi was compared between these methods.Results The detection rate for fungi was 20.69%by direct microscopy,37.9%by fungal culture,17.2%by one-round PCR,and 48.3%by two-round PCR.More than one species of fungus were detected in 6.9%(2/29),3.4%(1/29)and 24.1%(7/29)of these specimens by fungal culture.one-round PCR and two-round PCR, respectively.There was a significant difference in the detection rate between two-and one-round PCR(x2=6.34,P＜0.05).With regard to the detection rate for more than one species of fungus,two-round PCR was significantly higher than one-round PCR and fungal culture(x2=4.09,6.30.bom P＜0.05).Conclusion Two-round PCR may help to improve the sensitivity of molecular diagnosis of fungus-infected specimens.

Disinfectant and Antibiotic Resistance Genotypes in Escherichia coli Isolated from Urine / 中华医院感染学杂志

OBJECTIVE To investigate the disinfectant and antibiotic resistance genotypes in 60 strains of Escherichia coli isolated from urine.METHODS Sixty strains of E.coli isolated from inpatients′ urine were collected from Jan 2006 to Oct 2008.Antibiotic susceptibility tests for fifteen antibiotics were performed by Kirby-Bauer method.And three kinds of disinfectant and antibiotic resistance genes(qacE△1,tehA,merA)were analyzed by polymerase chain reaction(PCR) and DNA sequencing.RESULTS More than 70.0% of the sixty strains of E.coli were susceptible to imipenem,piperacillin/tazobactam,cefoxitin,amikacin and gentamicin,and less than 50.0% were susceptible to the other ten antibiotics.There were 42 strains with qacE△1 gene(70.0%),10 strains with merA gene(16.7%) and all strains with tehA gene.The sequence of the first strain was different from those reported in GenBank,so it was a new subtype.CONCLUSIONS There are 70% of E.coli strains isolated from urine samples with qacE△1 gene.And disinfectant resistance may be one of the main factors for hospital infection in the future.

Isolation and identification of Trichosporon inkin colonized in vagina / 中华皮肤科杂志

Objective To report a case of vaginal colonization due to Trichosporon inkin. Methods A 34-year-old female presented with increased vaginal discharge accompanied by abnormal odor for 2 months. Clinical laboratory examination was carried out. Cultures of vaginal discharge yielded yeast-like colony. Subsequently, the isolate underwent the following mycological examinations: purification, slide micro-culture, temperature test, urea enzyme test, biochemistry identification, antifungal susceptibility test, and gene sequencing. Results Gynecological examination revealed white homogeneous secretions attached to mucous membrane of the vagina. Nugent scores of vaginal discharge amounted to 5-6. Two rounds of culture of vaginal discharge resulted in stramineous, reductus and yeast-like colony. The isolate could grow in 42 ℃. Appressorium on the top of hypha and typical sarcinae formed in slide microculture of corn agar, and yeast malt agar was the optimal growth medium for it. Urea enzyme test was positive. API 20C AUX biochemical test and gene sequencing revealed that the isolate was consistent with Trichosporon inkin. The isolate was sensitive to amphotericin B and azoles such as clotrimazole and fluconazole, but resistant to flucytosine and caspofungin. Conclusions It is the first report of vaginal colonization due to T. Inkin in China. The accu-rate identification of T. Inkin relies on synthetic analysis of phenotype characteristics, biochemistry test and molecular sequencing.

Antimlcrobial resistance analysis among nosocomial gram-negative bacilli from 10 teaching hospitals in China in 2006 / 中华检验医学杂志

Objective To investigate antimicrobial resistance among nosocomial gram-negative bacilli in 2006.Methods About 987 consecutive and non-repetitive gram-negative bacilli were isolated from 10 teaching hospitals from Sep.to Dec.in 2006 in 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.Results The activity of antibacterial agents against Enterobacteriaceae was as fol lows in descending order of susceptible rate: meropenem(susceptible rate 99.8%),imipenem(99.5%),piperacillin/tazobactam(91.3%),amikacin (89.3%),cefepime(83.8%),cefoperazone/sulbactam(79.7%),ceftazidime(74.7%),cefotaxime (57.7%),ceftriaxone(56.6%),ciprofloxacin(53.6%).The prevalence of extended-spectrum β-Iactamases(ESBL)was 59.0% in Escherichia coli,33.0%in Klebsiella pneumoniae and 8.0%in Proteus mirabilis.The most active agents against E.coli and K.pneumoniae were meropenem,imipenem(99.2%. 100%),piperacillin/tazobactam(90.8%-97.0%),and amikacin(83.8%-92.4%).Cefepime Was more active against K.pneumoniae than E.coli(85.4% vs.65.2%).Against E.cloacae,E.aerogenes and Citrobacter freundii,the most active agents were as follows in desecnding order:meropenem,imipenem (99.2%-100%),amikacin(85.2%-92.6%),cefepime(81.5%-85.9%),piperacillin/tazobactam (73.4%-87.2%),cefoperazone/sutbactam(65.6%-77.7%),and ciprofloxacin(53.1%-72.3%).The most active agents against Pseudomonas aeruginosa were amikacin(83.5%),followed by meropenem (79.1%),piperacillin/tazobactam(74.1%),and imipenem(70.9%).The most susceptible agents against Acinetobacter baumannii were imipenem(79.1%),meropenem(73.4%) and cefoperazone/ sulbaetam(54.7%).Mutiresistant A.baumannii increased up to 53.0%.The most active agents against Burkholderia cepacia were meropenem(73.3%),eeflazidime(73.3%),and piperacillin/tazobactam (62.2%).Conclusions Carbapenems remained very high activity against Enterobacteriaceae.Increasing resistance to 10 antimicrobials agents tested from A.baumanni and P.aeruginosa brought great concern.

Antimicrobial Agents Including Cefmetazole Against Extended-spectrum Beta-lactamases-producing Enterobacteriaceae:An in vitro Susceptibility Investigation / 中华医院感染学杂志

OBJECTIVE To investigate in vitro activities of 12 antimicrobial agents including cefmetazole against extended-spectrum beta-lactamases-producing Escherichia coli(528 strains),Klebsiella pneumoniae(311 strains) and Proteus mirabilis(15 strains).METHODS They all collected from 15 teaching hospitals in China during 2005 and 2006 and included in the study.The levels of minimal inhibitory concentration(MIC) of 12 antimicrobial agents were determined by agar dilution method.WHONET 5.4 Software was used to analyze the data.RESULTS Against ESBLs-producing E.coli and ESBLs-producing K.pneumoniae,carbapenems were the most active antimicrobial agents(all 100.0% susceptible),followed by cephamycins(80.1-97.3%).Piperacillin/tazobactam(78.5-95.1%)showed a higher activity than cefoperazone/sulbactam(44.1-56.2%).The susceptible rate to ceftazidime against ESBLs-producing E.coli was remarkably higher than the other three cephalosporins,however the differences did not happen to ESBL-producing K.pneumoniae obviously.The susceptible rate to cefuroxime was below 1.6%.ESBLs-producing K.pneumoniae showed high sensitivity to carbapenems,cephamycins and ?-lactam/lactamase inhibitor combinations(all 100% susceptible),however the susceptible rates to cephalosporins were relatively lower.CONCLUSIONS Carbapenems and cephamycins remain the relatively high activity against ESBLs-producing Enterobacteriaceae.

Antimicrobial Resistance Surveillance on Hospital-and Community-acquired Pathogens in 10 Teaching Hospitals in China / 中华医院感染学杂志

OBJECTIVE To investigate the antimicrobial resistance of hospital-and community-acquired pathogens collected from 10 teaching hospitals located at different areas in China in 2006.METHODS According to the study protocol,the strains of Streptococcus pneumoniae,meticillin-susceptible Staphylococcus aureus(MSSA),Escherichia coli and Klebsiella pneumoniae were collected and sent to the central lab for reidentification and susceptibility testing.The minimal inhibitory concentrations(MICs) of antimicrobial agents against Str.pneumoniae were determined by Etest method and MICs of antimicrobial agents against S.aureus,E.coli and K.pneumoniae strains were determined by agar dilution method.WHONET5.4 software was used to analyze the data.RESULTS Among 353 Str.pneumoniae strains,74.2% were penicillin-susceptible(PSSP),9.6% were penicillin-intermediate(PISP) and 16.2% were penicillin-resistant(PRSP).Strains from different hospitals showed different sensitivity to penicillin.Among ?-lactam antibiotics,cefuroxime showed the lowest susceptibility rate of 0%(for PRSP) to 76.7%(for PSSP).The susceptibility rate to ceftriaxone and amoxicillin-clavulanic acid was 98.1% and 98.9% in PSSP group,61.8% and 64.7% in PISP group,and 15.8% and 10.5% in PRSP group.The ESBLs rate was 56.2% among 267 Escherichia strains and 42.7% among 206 K.pneumoniae strains.For ESBLs-producing strains,the susceptibility rates to cefotaxime and ceftriaxone were low and the rate to ceftazidime was relatively high among ?-lactam antibiotics.73.4% MSSA strains produced ?-lactamase.?-Lactam antibiotics tested showed high susceptibility against MSSA strains.The susceptibility rate was 98.9-100%.The susceptibility rate to ciprofloxacin and levofloxacin was 80.8% and 88.1%,separately.CONCLUSIONS Fluoroquinolones show high susceptibility against Str.pneumoniae.Ceftriaxone and amoxicillin-clavulanic acid have relatively high susceptibility among ?-lactams.For MSSA and non-ESBLs-producing E.coli and K.pneumoniae strains,?-lactams show high susceptibility.For ESBLs-producing E.coli and K.pneumoniae strains,the susceptibility rates to cefotaxime and ceftriaxone are low and that to ceftazidime,cefepime and cefoperazone-sulbactam are relatively high.

Comparison of in Vitro Antimicrobial Activity of Econazole with other Six Antibacterial Drugs / 中华皮肤科杂志

Objective To assess the antimicrobial actitivity of econazole nitrate in comparison with other six antibacterial drugs. Methods The minimal inhibitory concentrations (MICs) of econazole nitrate (Eco), neomycin (Neo), erythromycin (E), penicillin (P), cefotaxime sodium (Cef), ciprofloxacin (Cip) and amikacin (An) to 222 strains of Staphylococcus spp isolated from the lesions of patients with eczema and atopic dermatitis were determined by using the broth dilution method. Results MIC50 values of Eco were similar to Neo, Cip, An and Cef, and lower than those of P and E on methicillin-sensitive Staphylococcus aureus (MSSA); significantly lower than those of the other six antibacterial drugs on methicillin-resistant Staphylococcus aureus (MRSA); similar to An, Cip and P, and lower than those of Neo, Cef and E on methicillin-sensitive and coagulase-negative Staphylococcus (MSCNS); and similar to An, Cip P or Neo, and lower than Cef and E on methicillin-resistant and coagulase negative Staphylococus (MRCNS). Based on the NCCLS standards, the resistance rates of Cip, P and E were very high to either Staphylococcus areus or coagulase-negative Staphylococcus (CNS). The resistance rates of An and Cef of were lower to MSSA, but higher than 50% to MRSA. MIC90 value of Eco was similar to its MIC50, and lower than the MIC value reported in the literature. The MIC90 value of neomycin was muich higher than the MIC50 value of econazole. Conclusion Econazole nitrate has antibacterial activity to both Staphylococcus areus and CNS. MIC90 value of Eco is similar to its MIC50, and no resistance to Eco was found.