ABSTRACT
Objective@#The purpose of this study was to investigate the molecular characteristics of ESBL-encoding conjugative plasmid identified in muti-drug resistant Escherichia coli isolated from food.@*Methods@#465 Escherichia coli isolates were collected from national foodborne disease surveillance net from 2013 to 2014 (salad, n=159; meat, n=102; processed meat, n=95; cakes/rice, n=46; cooked dish, n=63). ESBLs strain was detected by Mueller-Hinton agar plate, and then its drug resistance was tested by agar dilution method. Polymerase chain reaction (PCR) and DNA sequencing were performed to identify the corresponding ESBL genes. Plasmids were typed by PCR-based replicon typing and their characteristics were determined by S1-nuclease pulsed-field gel electrophoresis method. Broth mating assays were carried out for all isolates to determine whether the ESBL marker could be transferred by conjugation.@*Results@#12 E. coli were found to be resistant to cefotaxime, and all of which were confirmed as ESBLs. The 12 isolates all carried different types of CTX-M genes resistant to drug, and 7 of which carried TEM type as well. All 12 isolates contained at least one plasmid and some had four plasmids, with size ranging from 47-to 220-kb by S1-PFGE anaylsis. Seven isolates demonstrated the ability to transfer their cefotaxime resistance marker to the recotper strain J53 by only one plasmid.@*Conclusion@#This study highlights the diversity of the multi-drug resistant E. coli and also the diversity of ESBL genes in China. Plasmids carrying these genes poses a serious threat to food safety in China.
ABSTRACT
In order to study the distribution of virulence genes of Listeria monocytogenes (Lm) in Hebei Province,29 virulence genes of Lm,including Listeria monocytogenes pathogenicity islands Ⅰ (LIPI-Ⅰ:prfA,plcA,plcB,hlyA,mpl and actA),10 internalins genes (inlA,inlB,inlC,inlD,inlE,inlF,inlG,inlH /C2,inlI and inlJ) and the other 13 virulence-associated genes (bsh,srtA,iap,sigB,virR,mprF,dltA,dltB,dltC,dltD,srtB,fbpA and hpt) were detected by PCR.Results showed that in the 91 Lm strains,the detection rate of 23 virulence genes were 100％.The 29 virulence genes of 26 Lm strains were all detected,and 65 Lm strains had different deletion of 6 virulence genes inlD,inlF,inlG,inlH /C2,inlJ and mpl.The deletion rate of inlG and inlF were 60.44％ and 54.95％,respectively,following by mpl gene,with a deletion rate of 19.78％.According to the absence of virulence genes,91 strains could be divided into 10 subtypes,and the dominant virulence subtypes was type Ⅰ with all 23 virulence genes.The deletion rate of virulent genes in Shijiazhuang was higher than that in northern Hebei.It is suggested that the rate of virulence gene of food-borne Lm in Hebei Province is high,and the virulence gene deletion patterns has diversity and regional differences.
ABSTRACT
Screening out the safety-related substances and establishing the corresponding standard has been a key research issue to improve the safety of traditional Chinese medicine injections(TCMIs). 5-HMF which widely exists in sugar-containing TCMIs has long been considered as an important safety-related substance. In this review, we summarizes the research progress on the toxicology of 5-HMF as well as the content and standards of 5-HMF in TCMIs.Therein, both literature summary and analysis results indicate that there are lack of toxicology researches of 5-HMF and its metabolites in TCMIs, although the potential toxicity of 5-HMF and its metabolites has been reported. Moreover, the content of 5-HMF largely varies from TCMIs to TCMIs, and even in the same TCMIs from different factories. To ensure the clinical efficacy of TCMIs, it urgent to carry out the study of the toxicology of 5-HMF in TCMIs comprehensively and systematically, so as to set up a relatively uniform standard as well as to develop process quality control method.
ABSTRACT
In order to develop a rapid and reliable method for B. cereus genotyping, factors influencing PFGE results, including preparation of bacterial cells embedded in agarose, lysis of embedded cells, enzymatic digestion of intact genomic DNA, and electrophoresis parameters allowing for reproducible and meaningful DNA fragment separation, were controlled. Optimal cellular growth (Luria-Bertani agar plates for 12-18 h) and lysis conditions (4 h incubation with 500 µg/mL lysozyme) produced sharp bands on the gel. Restriction enzyme NotI was chosen as the most suitable. Twenty-two isolates were analyzed by NotI digestion, using three electrophoretic parameters (EPs). The EP-a was optimal for distinguishing between isolates. The optimized protocol could be completed within 40 h which is a significant improvement over the previous methods.
Subject(s)
Bacillus cereus , Genetics , Bacteriological Techniques , DNA, Bacterial , Chemistry , Genetics , Electrophoresis, Gel, Pulsed-Field , MethodsABSTRACT
<p><b>AIM</b>To identify the serum biomarkers of prostate cancer (PCa) by protein chip and bioinformatics.</p><p><b>METHODS</b>Serum samples from 83 PCa patients and 95 healthy men were taken from a mass screening in Changchun, China. Protein profiling was carried out using surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF MS). The data of spectra were analyzed using two bioinformatics tools.</p><p><b>RESULTS</b>Eighteen serum differential proteins were identified in the PCa group compared with the control group (P < 0.01). There were four proteins at the higher serum level and 14 proteins at the lower serum level in the PCa group. A decision tree classification algorithm that used an eight-protein mass pattern was developed to correctly classify the samples. A sensitivity of 92.0% and a specificity of 96.7% for the study group were obtained by comparing the PCa and control groups.</p><p><b>CONCLUSION</b>We identified new serum biomarkers of PCa. SELDI-TOF MS coupled with a decision tree classification algorithm will provide a highly accurate and innovative approach for the early diagnosis of PCa.</p>
Subject(s)
Aged , Aged, 80 and over , Humans , Male , Middle Aged , Biomarkers , Blood , Decision Trees , Medical Informatics , Prostatic Neoplasms , Diagnosis , Proteome , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization , MethodsABSTRACT
<p><b>AIM</b>To investigate the pathological features of the prostate biopsy through mass screening for prostate cancer in a Chinese cohort and their association with serum prostate specific antigen (PSA).</p><p><b>METHODS</b>A total of 12027 Chinese men in Changchun were screened for prostate cancer by means of the serum total prostate specific antigen tPSA test (by Elisa assay). Transrectal ultrasound-guided systematic six-sextant biopsies were performed on those whose serum tPSA value was > 4.0 ng/mL and those who had obstructive symptoms (despite their tPSA value) and were subject to subsequent pathological analysis with the aid of the statistic software SPSS 10.0 (SPSS. Inc., Chicago. USA).</p><p><b>RESULTS</b>Of the 12027 cases, 158 (including 137 patients whose serum tPSA values were 4.0 ng/mL and 21 patients [serum tPSA < 4.0 ng/mL] who had obstructive symptoms) undertook prostate biopsy. Of the 158 biopsies, 41 cases of prostatic carcinoma were found (25.9 %, 41/158). The moderately differentiated carcinoma and poorly differentiated carcinoma accounted for 61% and 34%, respectively. A significant linear positive correlation between the serum tPSA and the Gleason scores in the 41 cases of prostatic carcinoma (r = 0.312, P < 0.01) was established. A significant linear positive correlation between the serum tPSA value of the 41 prostatic carcinoma and the positive counts of carcinoma in sextant biopsies was established (r = 0.406, P < 0.01), indicating a significant linear relationship between serum tPSA and the size of tumor.</p><p><b>CONCLUSION</b>This study was the first to conduct mass screening for prostate cancer by testing for serum tPSA values and the first to investigate the pathological features of prostate cancer in a cohort of Chinese men. Our results reveal that the moderately differentiated carcinoma is the most common type of prostate cancer. This study also has shown that the serum tPSA value in prostate cancer is associated with the Gleason score and the size of tumor.</p>
Subject(s)
Humans , Male , Biopsy , Methods , China , Mass Screening , Prostate-Specific Antigen , Blood , Prostatic Neoplasms , Blood , Diagnosis , Diagnostic Imaging , Pathology , UltrasonographyABSTRACT
<p><b>BACKGROUND</b>The incidence of prostate carcinoma (Pca) has been increasing in China. We detected Pca in elderly men in Changchun, north China and the significance of prostate specific antigen (PSA) in mass screening and clinical staging of Pca.</p><p><b>METHODS</b>Serum PSA from 12,027 men over 50 years old from Changchun was analyzed. In case of serum PSA greater than 4.0 ng/ml, the patient was suspected of potentially suffering from Pca, and transrectal six-point puncture prostate biopsies were performed under ultrasound guidance. Pathological examinations were performed on the biopsy tissue, and ABCD and TNM clinical stagings were used in accordance with international standards. Correlations between serum PSA level and clinical stage were analyzed.</p><p><b>RESULTS</b>PSA was greater than 4.0 ng/ml in 813 patients (6.8% of the 12,027 men). Transrectal six-point prostate puncture biopsies guided by ultrasound were performed in 273 patients (33.6% of the 813 patients who were tested positive in the initial mass screening). Of these 273 patients, 69 cases of Pca (25.3% of 273) were confirmed by biopsy in the second screening, with an overall detection rate for Pca of 0.57% (69/12,027). The total number of patients in stages A, B, T1, or T2 was 57.9%, and over 20% of them suffered from late stage Pca with lymph node and bone metastasis. An obvious positive correlation was observed between ABCD staging, TNM staging, and serum PSA level.</p><p><b>CONCLUSIONS</b>Serum PSA level is not only the golden standard for mass screening of Pca, but also the predictor for clinical stage of Pca. PSA testing revealed asymptomatic Pca cases in early, middle, and later stages in the elderly, suggesting that mass screening is of paramount importance.</p>