Objective To evaluate the effect of propofol on first spike latency (FSL) of inferior colliculus neurons and explore the electrophysiological mechanisms underlying the propofol-induced loss of heating.Methods Forty-three SD rats of both sexes weighing 200-250 g were used in this study.FSL was recorded with glass recording micro-electrode inserted in inferior colliculus.Propofol 100 mg/kg was administered intrapefitoneally.FSL was recorded before and every t0 min after propofol administration when sound intensity was between 90 dB SPL and 10 dB SPL before threshold.First-order exponential function was used to fit FSL-sound intensity curve at different time points before and after propofol administration.Results The inferior colliculus neurons showed offset response in one rat.FSL extended to 0.8 ms at 10 min after propofol administration.In the remaining 42 rats,the inferior colliculus neurons responded only to the beginning part of the sound.FSL was prolonged at 10 min after propofol administration.R2 of first-order exponential function ＞ 0.95 at different time points after propofol administration ( P ＜ 0.05 ).FSL-sound intensity curve was shifted parallelly upwards after administration.Conclusion Propofol affects auditory information transmission by extending FSL of rat inferior colliculus neurons but does not change the meaning of the information encoded by FSL.

Objective To explore the imaging differential diagnosis of vascular malformations and intermediary character hemangiomas.Methods The roentgenographic,CT and MRI findings of vascular malformations and intermediary character hemangiomas in 58 cases were analysed retrospectively.Results In 42 cases with vascular malformations,the lesions were irregular with definite margins,and 5 cases showed the bone compressed adjacent to the lesions.31 patients studied with MRI ,3 cases appeared as hyperintensity(equal to fat) and 28 cases appeared as mixed hyperintensity(higher than that of fat) on T2WI,20 cases showed circular markedly vessel-like hyperintensity on T2WI .In 16 cases with intermediary character hemangiomas,7 cases showed circular soft tissue masses,the masses were lobulated in 8 cases and "crab nail" in 1 case,5 cases showed edema of around the tumors and occupying effect on CT and MRI,3 cases showed bone corroded adjacent to the lesions,2 cases showed bony destruction.Of the 11 patients studied with MRI,the lesions showed hyperintensity on T2WI.Conclusion The imaging findings of vascular malformations and intermediary character hemangiomas are different.

Objective To investigate the distribution and antibiotic resistance of bacterial isolates from blood samples in pediatric patients in tertiary hospitals in Hubei area from 2006 to 2007.Methods Pathogenic bacteria isolated from blood samples of pediatric patients were collected from 17 tertiary hospitals in Hubei area from 2006 to 2007. All strains were isolated and identified by routine Methods . Antimicrobial susceptibility testing was conducted on all isolates using Kirby-Bauer Methods . Results A total of 941 strains were collected from January to December of 2006. The most common microorganism was coagulase-negative Staphylococcus (573, 60.9%), followed by Staphylococcus aureus (127, 13.5%), Enterococcus faecalis (33, 3.5%), Escherichia coli (16, 1.7%). A total of 969 strains were collected from January to December of 2007. The most common species was coagulase negative Staphylococcus (583, 60.2%), followed by S. aureus (162, 16.7%), E. faecalis (28, 2.9%), E. coli (21, 2.2%), E. faecium (11, 1.1%), Salmonella choleraesuis (11, 1.1%). Of the isolates collected during 2006, the prevalence of methicillin-resistant S. aureus (MRSA) was 71.7%. The prevalence of ESBLs was 56.2% in E. coli. Of the isolates collected during 2007, the prevalence of MRSA was 79.6%. The prevalence of ESBLs was 47.6% in E. coli. MRSA strains were more resistant to antibiotics than methicillin-susceptible S. aureus (MSSA). No glycopeptide-resistant strain was identified in Staphylococcus. Conclusions Staphylococcus is the most frequently isolated pathogen from blood samples of pediatric patients in tertiary hospitals in Hubei area.

Objective To investigate antibiotic resistance and resistant trend of Streptococcus pneumonia. Methods To investigate 753 Streptococcus pneumoniae isolated from Tongji Hospital in recent 10 years from January 1st 2000 to December 31st 2009, most of them were from respiratory tract specimens,followed by blood and cerebrospinal fluid. The MIC to penicillin & cefatriaxone were determined by E-test,and other antimicrobial susceptibility were tested by Kirby-Bauer method. Results For non-cerebrospinal fluid specimen, the total rate of PNSSP was 23.8%( 93/392 ), it was significant different between the rate of PNSSP from children ( 26. 4%, 47/178 ) and adults ( 16. 8%, 36/214, χ2 = 7. 642, P ＜ 0. 01 ). All of 10 strains isolated from cerebrospinal fluid were PRSP. Most isolates were high-susceptive to moxifloxacin and levofloxacin, and the rate of susceptibility were 96. 9% ( 720/743 ) and 90. 5% ( 672/743 )respectively. None of Streptococcus pneumonia was resistant to vancomycin and meropenam. The resistant rate of most tested antibiotics increased in different degree year by year, especially penicillin, erythromycin and clindamycin. The rate of PNSSP was only 19%( 19/99 )in 2006 ,but in 2009 the rate increased to 30%( 35/114 ). The susceptibility rate of erythromycin was 22% ( 28/125 )in 2000, but only 3% ( 3/114 )in 2009 ;and the susceptibility rate of clindamycin decreased from 40% ( 13/32 ) in 2004 to 4% (5/114) in 2009. Conclusions From 2000 to 2009, Streptococcus pneunoniae was more likely resistant to penicillin,erythromycin and clindamycin year by year, especially those isolates recovered from children. It was suggested that antibiotics should be chosen to use according to antimicrobial susceptibility test results.

Objective To investigate the antimicrobial resistance in the clinical strains isolated from Tongji Hospital to the antimicrobial agents commonly used in 2012.Methods Antimicrobial susceptibility was tested by Kirby-Bauer method.The minimum inhibitory concentration (MIC) of penicillin and ceftriaxone for Streptococcus pneumoniae and vancomycin for Staphylococcus spp.were determined by E-test.All data were analyzed by WHONET 5.6 software.Results A total of 8 191 strains were isolated in 2012,including gram-positive bacteria (2 815,34.4%)and gram-negative bacteria (5 376,65.6%). The top five pathogenic bacteria isolated from outpatients were Escheria coli,Pseudomonas aeruginosa,coagulase-negative Staphylococcus (CNS),Klebsiella spp.and Staphylococcus aureus.For the isolates from non-ICU inpatients,the top five were E.coli,S.aureus,Acinetobacter spp.,Klebsiella spp.and P.aeruginosa.For those isolated from ICU patients,the top five were Acinetobacter spp.,S.aureus,P.aeruginosa,Enterococcus spp.and E.coli.The prevalence of MRSA and MRCNS was 58.1% and 64.3%,respectively.Seventeen strains of vancomycin resistant Enterococcus were identified, including 13 strains of E.faecium with VanA and 4 strains of E.gallinarum with VanA and VanC.The percentage of antimicrobial resistance in E.faecium was significantly higher than that in E.faecalis (P<0.05).A total of 94 strains of carbapenem-resistant Enterobacteriaceae were detected.The prevalence of penicillin-non-susceptible S.pneumoniae in children was much higher than that in adults. The prevalence of carbapenem-resistant P.aerugonosa and Acinetobacter spp. was 28.1% and 56.2% respectively.Beta-lactamase was produced in 41.8% of the H.influenzae and 98.6% of the M. catarrhalis isolates. Conclusions The prevalence of multidrug resistant strains has been increasing, especially vancomycin-resistant Enterococcus and carbapenem-resistant Enterobacteriaceae.

Objective To investigate distribution and drug resistance of pathogenic bacteria in lower respitatory tract infection. Methods Distribution and drug resistance of pathogenic bacteria in lower respitatory tract infection of patients in ICU and non-ICU of our hospital during 2013 were retrospectivly analyzed. The pathogens were identified by manual methods routinely and those difficult to be identified were analyzed by using the VITEK-2-COMPACT instrument. Antimicrobial susceptibility of these isolates were tested by Kirby-Bauey methods routinely. Results In total, 956 strains were isolated from lower respitatory tract infection of patients in ICU, including 231 strains of gram-positive cocci (24. 2%), 680 strains of gram-negative bacteria (71. 1%), 45 strains of fungi (4. 7%). In patients of non-ICU, 4 464 strains were isolated, including 1 090 strains of gram-positive cocci (24. 4%), 3 226 strains of gram-negative bacteria (72. 3%), and 148 strains of fungi (3. 3%). Staphylococcus aureus, acinetobacter baumannii and pseudomonas aeruginosa were the most frequent isolates in patients of ICU and non-ICU. The overall prevalence of methicillin resistant staphylococcus aureus (MRSA) in staphylococcus aureus was 87. 0%in ICU and 74. 0% in non-ICU. MSSA was sensitive to the most antibiotics ( more than 80. 0% of the strains were sensitive to common antibiotics) except penicillin, erythromycin and clindamycin. MRSA was sensitive to trimethoprim-sulfamethoxazole and fosfomycin (more than 75. 0% of the strains were sensitive to the antibiotics) except for vancomycin, teicoplanin and linezolid. Acinetobacter baumannii was more resistant to the antibiotics (less than 40. 0% of the strains were susceptible to the antibiotics). Pseudomonas aeruginosa from ICU was more resistant to the antibiotics ( less than 50. 0% of the strains were sensitive to the antibiotics) than that from non-ICU. Stenotrophomonas maltophilia was sensitive to trimethoprim-sulfamethoxazole, levofloxacin and minocycline (more than 80. 0% of the strains were sensitive to the antibiotics). Escherichia coli and Klebsiella pneumoniae were sensitive to Piperacillin-tazobactam and Amikacin except for meropenem and imipenem ( more than 80. 0% of the strains were sensitive to the antibiotics) . Conclusion Gram-negative bacteria was the most frequent isolate in lower respitatory tract infection of our hospital during 2013. Staphylococcus aureus, acinetobacter baumannii and pseudomonas aeruginosa were the most frequent isolates in ICU and non-ICU. Resistance to the antibiotics was more common in ICU than in non-ICU. Antibiotics should be prescribed according to bacterial resistance results reasonably in order to prevent the spread of drug-resistant strains.

Objective To evaluate the capability of four tests for identification of the in vitro suscepti-bility of tigecycline against Acinetobacter and Enterobacteriaceae isolates.Methods Disk diffusion test was per-formed to detect the sensitivity of 158 Acinetobacter and 339 Enterobacteriaceae isolates to tigecycline.The mini-mum inhibitory concentrations ( MICs) of tigecycline for non-sensitive isolates were detected by using broth dilu-tion method ( BDM) , MIC Test Strip ( MTS) and agar dilution method.The differences with antimicrobial sus-ceptibility among the four different methods were evaluated.Results Tigecycline showed good antibacterial ac-tivity against both non-sensitive Acinetobacter and Enterobacteriaceae isolates with most of the MIC50 values in the sensitivity range of (0.5-2) mg/L and all of the MIC90 values of 4 mg/L.The MIC50 and MIC90 values measured by BDM were respectively 1 mg/L and 4 mg/L.The sensitivity rates presented by the results of BDM were re-spectively 87.1%and 70.2%based on the standards made by Food and Drug Administration (FDA) and Euro-pean Committee on Antimicrobial Susceptibility Testing ( EUCAST) .Agar dilution method indicated that most of the MICs of tigecycline to Acinetobacter and Enterobacteriaceae isolates were two dilutions higher than those de-tected by BDM with essential agreement (EA) rate of 56.5%.Both the very major error (VME) and the major error (ME) values were 0 and the categorical agreement (CA) rate was 46.8%according to the FDA standard.The VME and CA values were 0.8% and 24.2% based on EUCAST standard.Compared with agar dilution method, MTS showed better results in determining the susceptibility of Acinetobacter and Enterobacteriaceae iso-lates to tigecycline with MIC50 and MIC90 values of 1.5 mg/L and 4 mg/L, which was similar to the capability of BDM.Referring to the FDA and EUCAST standards, the sensitivity rates were 83.1% and 21.0%, the CA rates was 81.5%and 29.8%, and the EA rate was 71.8%.Most of the results tested by MTS were one dilution higher than those by BDM.FDA standard showed better correlation than EUCAST standard.Disk diffusion method showed the ME, mE, VME and CA values were respectively 19.4%, 71.8%, 0 and 8.9%according to FDA standard.Conclusion Disk diffusion method, MTS and agar dilution method all showed differences with BDM in susceptibility testing.The capability of MTS was similar to that of BDM.The results evaluated by FDA standard were better than those by EUCAST standard.The in vitro susceptibility of bacteria to tigecycline could be tested by disk diffusion method using FDA standard for evaluation, and confirmed with MTS if isolates were resistance or intermediate strains.The BDM could be performed for further confirmation if necessary.

Objective To investigate the antimicrobial resistant mechanisms of carbapenemrcsistant Entcrobactcriaceae (CRE),construct monitoring system of acquired carbapenemase.Methods Totally 5604 clinical isolates of Enterobacteriaceae in Tongji Hospital were collected from January 2007 to June 2010,including 100 isolates of which zone diameters of meropenem were not larger than 21 mm.Antibiotic susceptibility was performed to select CRE.Then,carbapanemase gene and genetie structure screenings were perforomed by polymerase chain reaction (PCR).Pulsed-field gel electrophoresis (PFGE) and Southern blot were used to analyze the plasmids of CRE.Multilocus sequence typing (MLST) was used to determine the genotypes and homology of these isolates.In addition,out membrane proteins were examined by sodium dodecyl sulfate polyacrylamide gel electrophoresis ( SDS-PAGE ).Results Eleven isolates of CRE were collected and confirmed,most of them were Klebsiella.spp.( 7/11 ).Susceptibility of antimicrobial agents indicated that all these strains resistant to most antimicrobials.The minimal inhibitory concentration (MIC) range of meropenem were 8 - 64 mg/L,imipenem were 4 - 64 mg/L,ertapenem were 4 - 64 mg/L.However,susceptibilities of aminoglycosides and fluoroquinoloncs were significantly different.PCR results showed that six isolates were blaIMP-4 positive and three isolates were blakPC.2 positive,including one isolate of K.pneumoniae (ST476) carrying both blaIMP-4 and blaKPC-2 genes.Genetic structure of carbapenemase genes were analyzed,suggesting that blaKPC-2 located in an integrated structure of a Tn3-based transposon and partial Tn4401 segment.PFGE showed that most CRE contained three or more plasmids.Two isolates of K.pneumoniae were assigned to the same sequence type,ST476,by MLST.SDS-PAGE indicated that only one isolate (Kox656) lacked two out membrane proteins ( OmpK35 and OmpK36 ).Conclusions The most common carbapenemase-resistant Enterobacteriaceae was K.pneumoniae in our hospital.Producing IMP-4 was the most common reason that bacteria resistant to carbapencms.The concomitant presence of these genes poses therapeutic as well as infection control problems.Attention should be payed to the characteristies of bacterial resistance and clinical epidemiology of drug-resistant infections in hospital,and thus to provide clinical reference.

Objective To study the clinical feature of carbapenem-resistant klebsiella pneumoniae (CRKP) neonatal sepsis.Method From January 2012 to December 2017,clinical data of newborns with klebsiella pneumoniae (Kp) sepsis admitted to the NICU of our hospital were retrospectively analyzed.Clinical manifestations,laboratory examinations,risk factors,treatments and outcomes were compared between newborns with CRKP sepsis and newborns with carbapenem-sensitive klebsiella pneumoniae (CSKP) sepsis.Result A total of 71 strains of Kp were isolated,representing 33.2％ of all isolated pathogens (71/214).Among 71 newborns diagnosed with Kp sepsis,35 were CRKP sepsis and the other 36 were CSKP sepsis.The incidence of dyspnea/apnea in CRKP group was significantly higher than CSKP group (85.7％ vs.55.6％,P=0.005).Newborns in CRKP group had smaller gestational age than CSKP group.The proportions of male gender,the incidences of continuous positive airway pressure treatment,parenteral nutrition and antibiotics exposure (cephalosporins,penicillins or carbapenems) before the onset of sepsis in CRKP group were higher than CSKP group and the hospital stay before sepsis was longer than CSKP group,the differences were statistically significant (P＜0.05).Logistic regression analysis showed that male gender (OR=8.125,95％CI 2.275～29.021),parenteral nutrition (OR=27.730,95％CI 2.948～260.858) and carbapenems exposure before onset (OR=4.849,95％CI 1.091～21.554) were independent risk factors of neonatal CRKP sepsis (P＜0.05).The mortality rate of CRKP group was higher than the CSKP group (22.9％ vs.5.6％,P=0.036).Conclusion Male,parenteral nutrition and carbapenems exposure before onset were independent risk factors of neonatal CRKP sepsis.CRKP sepsis is critical and has a high mortality rate.Clinicians should monitor drug resistance carefully,follow antibiotics stewardship principles and establish enteral nutrition as soon as possible.

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 .