Identification and antimicrobial resistance of Escherichia coli isolates from chicken in different provinces / 中国人兽共患病学报

The aim of this study was to determine the prevalence and antibiotic susceptibility of Escherichia coli from retail raw chickens in different provinces of China.A total of 1 152 whole chicken samples were collected and screened for the prevalence of E.coli,and then the E.coli isolates were further tested for the antimicrobial susceptibility using agar dilution method.Results showed that the overall positive rate for E.coli in retail chickens was 65.97％ (760/1 152);resistance was most common to nalidixic acid (66.84％),followed by amoxicillin-clavulanic acid (66.05％),tetracycline (65.00％),trimethoprim-sulfamethoxazole (63.16 ％),ampicillin (60.66 ％),amoxicillin (51.32 ％),streptomycin (50.39 ％),chloramphenicol (48.32 ％),kanamycin (38.29 ％),gentamicin (26.31％),ciprofloxacin (25.79 ％) and cefoxitin (21.05 ％).The last were gatifloxacin,cefoperazone and amikacin (each ＜20％).Overall,70.53％ of the isolates were resistant to at least three antimicrobials.A large proportion of multidrug resistant isolates were resistant to 8 kinds of antimicrobials (10.26 ％).No strain was resistant to 15 kinds of antimicrobials.Furthermore,isolates recovered from different regions exhibited different resistance levels to most antimicrobials.Our findings indicate that retail chicken in China was commonly contaminated with E.coli,and many E.coli strains exhibited multiple drug resistance.Presence of multiple drug E.coli in raw chickens may pose a potential threat to human health.

The development of a fluorescence polarization immunoassay for aflatoxin detection / 生物医学与环境科学（英文）

A fluorescence polarization immunoassay (FPIA) was developed for the analysis ofaflatoxins (AFs) using an anti-aflatoxin B1 (AFB1) monoclonal antibody and a novel fluorescein-labeled AFB1 tracer. The FPIA showed an IC50 value of 23.33 ng/mL with a limit of detection of 13.12 ng/mL for AFB1. The cross-reactivities of AFB1, AFB2, AFG1, AFG2, AFM1, and AFM2 with the antibody were 100%, 65.7%, 143%, 23.5%, 111.4%, and 2%, respectively. The group-specificity of anti-AFB1mAb indicated that the FPIA could potentially be used in a screening method for the detection of total AFs, albeit not AFG2 and AFM2. The total time required for analyzing 96 samples in one microplate was less than 5 min. This study demonstrates the potential usefulness of the FPIA as a rapid and simple technique for monitoring AFs.

Development of a rapid multi-residue assay for detecting β-lactams using penicillin binding protein 2x* / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To develop a rapid multi-residue assay for detecting 16 demanded by the European Union (EU).</p><p><b>METHODS</b>A recombinant penicillin-binding protein (PBP) 2x* from Streptococcus pneumoniae R6 was expressed in vitro and six β-lactams were conjugated to HRP by four methods. A rapid multi-residue assay for β-lactams was established with PBP2x* and HRP-conjugate.</p><p><b>RESULTS</b>PBP2x* was expressed and purified successfully and the ideal HRP-conjugate was identified. The multi-residue assay was developed. After optimization, penicillin G, ampicillin, amoxicillin, cloxacillin, dicloxacillin, oxacillin, nafcillin, cephalexin, ceftiofur, cefalonium, cefquinome, cefazolin, cefoperazone, cephacetrile, and cephapirin can be detected at levels below MRL in milk with simple pretreatment.</p><p><b>CONCLUSION</b>This assay developed can detect all 16 β-lactams demanded by the European Union (EU). The whole procedure takes only 45 min and can detect 42 samples and the standards with duplicate analysis.</p>

Development of an enzyme-linked immunosorbent assay for determination of the furaltadone etabolite, 3-amino-5-morpholinomethyl-2-oxazolidinone (AMOZ) in animal tissues / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To determine 3-amino-5-morpholinomethyl-2-oxazolidinone (AMOZ) residues released from protein bound AMOZ in animal tissues.</p><p><b>METHODS</b>Polyclonal and monoclonal antibodies were produced in this study. A rapid, sensitive, and specific competitive direct enzyme-linked immunosorbent assay (cdELISA) was developed.</p><p><b>RESULTS</b>Rabbit polyclonal antibodies were used in the optimized cdELISA method, and exhibited negligible cross-reactivity with other compounds structurally related to AMOZ. The IC(50) of the polyclonal antibody was 0.16 ng/mL. The method limit of detection in four different types of animal and fish tissues was less than 0.06 μg/kg. Recoveries ranged from 80% to 120% for fortified samples with the coefficient of variation values less than 15%. The results of the cdELISA method were in good agreement with the results from an established liquid chromatography-tandem mass spectrometry confirmatory method used for AMOZ residues.</p><p><b>CONCLUSION</b>The cdELISA method developed in the present study is a convenient practical tool for screening large numbers of animal and fish tissue samples for the the detection of released protein bound AMOZ residues.</p>

Expression of RRM1 and ERCC1 genes in tumor tissues and peripheral blood lymphocytes of advanced non-small cell lung cancer / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To investigate the expression of RRM1 and ERCC1 genes in tumor tissues and peripheral blood lymphocytes of advanced non-small cell lung cancer (NSCLC).</p><p><b>METHODS</b>Tissue and peripheral blood samples were collected from 49 advanced NSCLC patients treated with gemcitabine plus carboplatin. The expressions of RRM1 and ERCC1 mRNA in tumor tissue and peripheral lymphocytes were detected by real-time fluorescent quantitative PCR. The relationship of gene expression with clinical characteristics,chemotherapy response and prognosis was analyzed.</p><p><b>RESULTS</b>The RRM1 expression in tumor tissues was positively correlated with that in peripheral blood lymphocytes,while no significant correlation was observed between ERCC1 expression in tumor tissues and that in peripheral blood (rs=0.332 and 0.258; P=0.020 and 0.073, respectively). The expression of RRM1 and ERCC1 in tumor tissues peripheral lymphocytes was synchronous (rs=0.634 and 0.351; P<0.001 and 0.013, respectively). There was no significant correlation of gene expression with gender, age, smoking status, performance status, clinical stages and histological types of patients (P>0.05). Significant difference was found in response rate to chemotherapy (P<0.05,P<0.01,P<0.05),median survival time (P<0.05,P<0.01,P<0.05) and 1-year survival rate (P<0.01,<0.05,P<0.05) between patients with low RRM1 and ERCC1 expression levels in tumor tissues or low RRM1 expression levels in peripheral blood and those with high RRM1 and ERCC1 expression levels. The patients with low ERCC1 expression levels in tumor tissues gained higher 2-year survival rate (P<0.05). There was no correlation of the expression of ERCC1 in peripheral blood with the response to chemotherapy and prognosis (P>0.05).</p><p><b>CONCLUSION</b>The expression of RRMI and ERCC1 genes in tumor tissues and RRM1 in peripheral blood lymphocytes is closely correlated with the response to chemotherapy and prognosis of patients with advanced NSCLC treated with gemcitabine plus carboplatin.</p>

Clinical and coronary characteristics of young patients (< 30 years old) with acute myocardial infarction / 中华心血管病杂志

<p><b>OBJECTIVE</b>To explore the clinical characteristics and angiographic features of acute myocardial infarction in patients aged 30 years or younger.</p><p><b>METHODS</b>Data of 360 consecutive patients referred to Peking Union Medical College Hospital for evaluation of chest pain or discomfort from January 2007 to December 2009, diagnosed as acute myocardial infarction and underwent emergent coronary angiography were analyzed. Seven patients (1.9%) with age ≤ 30 years [4 male, (25 ± 5) years] were included in this study, patients were followed up for (12 ± 9) months.</p><p><b>RESULTS</b>There were 6 cases of ST-segment elevated myocardial infarction and 1 non-ST-segment elevated myocardial infarction. The culprit vessels were as follows: 5 left anterior descending artery, 1 left main and 1 right coronary artery. All 3 female patients were complicated with congenital coronary malformation or autoimmune disease, including 1 coronary artery aneurismal dilation of left anterior descending, 1 Takayasu's arteritis and 1 systemic lupus erythematosus. Three of the 4 male patients were smokers. Two patients underwent percutaneous coronary intervention. There was no death or cardiovascular re-admission during the follow-up.</p><p><b>CONCLUSIONS</b>The majority of acute myocardial infarction in patients aged 30 years or younger were presented with ST-segment elevated myocardial infarction and single vessel non-obstructive lesion. The most common culprit vessel was left anterior descending artery. All female patients were complicated with congenital coronary malformation or autoimmune disease. The short-term prognosis in patients of this cohort was good.</p>

Side branch occlusion rate at sites of overlapping sirolimus- or paclitaxel-eluting stents for treating long coronary lesions / 中华心血管病杂志

<p><b>OBJECTIVE</b>To compare side branch occlusion rate at sites of overlapping sirolimus- or paclitaxel-eluting stents in treating long coronary lesions.</p><p><b>METHODS</b>We retrospectively reviewed the PCI CD and medical records of PCI 141 patients with at least one stent overlapping for long coronary lesion in our institute from January 2004 to October 2007. The side branches occlusion was documented and analyzed.</p><p><b>RESULTS</b>The study population were consisted of 141 patients that there were 115 man, and 26 women, who got 297 stents. There were 154 side branch vessels been observed. Side branch occlusion rate was 24.6% in Cypher group and 31.6% in TAXUS (P > 0.05), side branch TIMI flow decrease rate on overlapping region was 26.3% in Cypher group and 68.4% in TAXUS group (P > 0.05). A logistic regression model analysis show that the significant risk factors for side branch occlusion is the diameter and ostial occlusion of side branch.</p><p><b>CONCLUSION</b>Side branch occlusion rate and TIMI flow decrease rate were similar on overlapping region in patients treated with Cypher or TAXUS stents for long coronary lesions. The significant predictors for side branch TIMI flow decrease are the diameter and ostial occlusion of side branch.</p>

Antimicrobial susceptibility and molecular detection of chloramphenicol and florfenicol resistance among Escherichia coli isolates from diseased chickens

Seventy Escherichia coli isolates recovered from diseasedchickens diagnosed with colibacillosis in Henan Province,China, between 2004 and 2005 were characterized forantimicrobial susceptibility profiles via a broth doublingdilution method. Overall, the isolates displayed resistanceto trimethoprim-sulfamethoxazole (100%), oxytetracycline(100%), ampicillin (83%), enrofloxacin (83%), and ciprofloxacin(81%), respectively. Among the phenicols, resistance wasapproximately 79% and 29% for chloramphenicol andflorfenicol, respectively. Molecular detection revealed thatthe incidence rates of the floR, cmlA, cat1, cat2 and cat3were 29, 31, 16, 13, and 0%, respectively. Additionally,10% of the isolates were positive for both floR and cmlA.As these antimicrobial agents may potentially inducecross-resistance between animal and human bacterialpathogens, their prudent use in veterinary medicine ishighly recommended.