OBJECTIVE To investigate antibiotic resistance and the prevalence of serotype of Streptococcus pneumoniae in Wuhan.METHODS Totally 152 strains of S.pneumoniae were collected to test the MICs of various antibiotics by agar dilution method according to the approved standard of NCCLS.Serotyping of S.pneumoniae was performed by using quelling reaction.RESULTS Among 152 strains of S.pneumoniae,65(42.76%) strains were resistant to penicillin(MIC≥0.12mg/L).94.08%,50.66%,41.45% and 11.18% of S.pneumoniae were resistant against the first(cefalexin),second(cefaclor) and third(cefaxime and ceftriaxone) generation of cephalosporins respectively.The resistance rates to other antibiotic agents,such as erythromycin,tetracycline,trimethoprim/sulfamethoxazole and chloramphenicol,were 84.21%,88.82%,89.47% and 18.42%,respectively.Strains that were resistant to levofloxacin and moxifloxacin were found both for 1.32%.Twenty serotypes were involved in 152 strains. The prevalent serotypes were 19(25.66%),23(19.08%),6(13.82%),15(7.24%)and 14(4.61%).Eight strains were remained for unable to serotype.All penicillin-resistant S.pneumoniae was included in serotypes 6,19 and 23.CONCLUSIONS The antibiotic resistance of S.pneumoniae is serious in Wuhan.Most of them are multi-resistant strains.Except for fluoroquinolones,ceftriaxone and chloramphenicol, most antibiotic agents have lost there activities against S.pneumoniae.The prevalent serotypes,especially of the multi-resistant strains,were 19,23 and 6.Pneumococcal polyvalent vaccine can well cover these serotypes.

Objective To study on chromosome-and plasmid-mediated fluoroquinolones-resistant in Escherichia coli isolated from fecal samples of chicken,swine and people around the farm.Methods Anti-microbial susceptibility testing was carried out by disk diffusion testing and bmth microdilution testing.gyrA,gyrB,parC,pareE,qnr and aac(6')-I b-cr were examined by PCR,and the products were sequenced.Ex-presion of aac(6')-I b-cr by conjunction was tested too.Results The resistance to antimicmbial agents was much higher in strains isolated from chicken than that from swine and human.Among the E coli strains examined by PCR,most resistant strains carried two mutations in gyrA and/or two mutations in parC.In ad-dition,some resistant strains had mutations in parE with MIC of ciprofloxacin>16μg/ml.No(resistance) mutation was found in gyrB.Seven strains(25.O%)and one strain(11.1%)had aac(6)-I b-cr,variant isolated from chicken and swine,respectively.The strains harboring cr variant enzyme reduced the suscepti-bility to ciprofloxacin and norfloxacin by N-acetylation of the drugs. Conclusion There is a close relation-ship between high level quinolone resistance and the numbers of amino acid exchange in DNA gyrase and to-poisomeraae IV,and aac(6)-I b-cr may play some role for fluoroquinolone resistance.

Objective To characterized the Salmonella enterica serotype typhimurium isolates recovered during 2002 to 2005 from outpatients in Tongji Hospital, Wuhan China. Methods The 36 isolates from Tongji Hospital were characterized by antimicrobial-susceptibility testing and screened for class Ⅰ integrons, beta-lactamase genes, qnr, aac(6')-Ib-cr and mutations in the quinolone resistance determining regions (QRDRs) by PCR and DNA sequence analysis. All isolates were also characterized by pulsed-fieldgel electrophoresis (PFGE) to determine the genetic relateness among these isolates. Results All isolates displayed multidrug resistance and most of them harbored class Ⅰ integrons. Ciprofloxacin-resistant isolates showed significant difference compared with ciprofloxacin-susceptible isolates after PFGE analysis. All 31 ciprofloxacin resistant isolates carried at least three mutations in the QRDR of GyrA and ParC. Three ciprofloxacin resistant isolates had accumulated additional mutation in ParE. Five isolates harboring the OXA-30. Enzyme showed intermediate resistant to eefepime. Conclusions Fluoroquinolone-resistant Salmonella typhimurium isolates were widely distributed among the outpatients in Wuhan and the resistant isolates accumulated multiple antimicrobial resistant mechanisms and showed unique genetic profiles. The state and local health authority must remain vigilant for the emergence of Salmonella typhimurium resistant to both third generation cephalosporins and fluoroquinolonos.

Objective To study on plasmid-mediated quinolone-resistant in Escherichia coli strains isolated from fecal samples of chicken and swine from the nine farms around our country.Methods Antimi-crobial susceptibility testing was carried out by broth microdilution testing,gyrA,gyrB,parC,qnr and aac (6')- Ⅰ b-cr were examined by PCR,and the products were sequenced.Conjugation experiment was carried out to proved that the plasmid-mediated quinolone resistance was transferable.Results In the total 818 animal isolates,qnr and aac genes were detected in 38 (4.6%) and 75 (9.2%) strains.The qnrA,qnrB,and qnrS genes were detected in 1 (0.1%),9 (1.1%) and 28 (3.4%) of the isolates.All isolates were negative for qnrC,qnrD genes.Conclusion There is a close relationship between high level quinolone resistance and plasmid-mediated quinolone resistance.The results of the current study highlight food-producing animals as a potential reservoir of antimicrobial-resistant bacteria and clinically important resistance genes.More attention should be paid to the surveillance of such strains.

Objective To characterize the roles of different quinolone resistance mechanisms in quinolone-resistant Escherichia coli isolates,including different topoisomerase point mutations,efflux pumps and outer membrane proteins.Methotis Through homologous gene recombination methods,different quinolone-resistant mechanisms of E. coli mutants were constructed and the susceptibility changes of these mutants to different antimicrobials were measured.Resuits Efflux pumps AcrAB and outer membrane protein TolC played different roles in different E. coli isolates.Compared with other mechanisms,the mutations in topoisomerases played a dominant role in quinolone resistance.Only the mutations jn parC had no effect on quinolone resistance,which further confirmed parC was the secondary target of quinolones in E.coli.Fluoroquinolone susceptible E.coli would automatically become highly resistant to quinolones after acquiring the point mutations in both gyrA(S83L,D87N)and parC(S80I,A108V),but not requiring the over-expres-sion of efflux.Conclusion The mutations in topoisomerases play a dominant role in E.coli quinolone resistance,and the mutations in both gyrA and parC are required.

The distinction of antimicrobial resistance of clinical bacteria isolated from county hospitals and a teaching hospital was investigated. Disc diffusion test was used to study the antimicrobial resistance of isolates collected from county hospitals and a teaching hospital. The data was analyzed by WHONET5 and SPSS statistic software. A total of 655 strains and 1682 strains were collected from county hospitals and a teaching hospital, respectively, in the year of 2003. The top ten pathogens were Coagulase negative staphylococci (CNS), E. coli, Klebsiella spp., S. areus, P. aeruginosa, Enterococcus spp., Enterobacter spp., otherwise Salmonella spp., Proteus spp., Shigella spp. in county hospitals and Streptococcus spp., Acinetobacter spp., X. maltophilia in the teaching hospital. The prevalence of multi-drug resistant bacteria was 5% (4/86) of methicillin-resistant S. areus (MRSA), 12% (16/133) and 15.8% (9/57) of extended-spectrum beta-lactamases producing strains of E. coli and Klebsiella spp., respectively, in county hospitals. All of the three rates were lower than that in the teaching hospital and the difference was statistically significant (P < 0. 01). However, the incidence of methicillin-resistant CNS (MRCNS) reached to 70% (109/156) in the two classes of hospitals. Generally, the antimicrobial resistant rates in the county hospitals were lower than those in the teaching hospital, except the resistant rates of ciprofloxacin, erythromycin, clindamycin, SMZco which were similar in the two classes of hospitals. There were differences between county hospitals and the teaching hospital in the distribution of clinical isolates and prevalence of antimicrobial resistance. It was the basis of rational use of antimicrobial agents to monitor antimicrobial resistance by each hospital.

Objective To explore the diagnostic value of multi-slice spiral CT with big field of view,thin slice thickness,and postprocessing in endobronchial tuberculosis Methods Ninety-eight clinically diagnosed and tuberculosis bacillus positive patients were included The multi-slice spiral CT was performed using 3 mm thickness scan,MiIP,CVR,and CTVE management The CT diagnosis was made by the single-blind method and was compared with fiberoptic bronchoscope and pathology Results Main CT features were as follows: obstruction of bronchia in 13 cases (9 6%),uniform stricture of bronchia in 27 cases (19 8%),and non-uniform stricture of bronchia in 96 cases (70 6%) The lesions located in the main bronchia in 31 (22 8%),pulmonary lobar bronchia in 81 (59 6%),and pulmonary segmental bronchia in 24 (17 7%),respectively Multiple lesions were found in 56 cases (51 7%) The sensitivity,specificity,and accuracy of multi-slice spiral CT in the diagnosis of endobronchial tuberculosis were 89 8%,63 2%,and 84 6%,respectively Conclusion The exertion of multiple functions of multi-slice spiral CT can increase the diagnostic level for endobrochial tuberculosis,and spiral CT is a good supplementary to fiberoptic bronchoscope

The aim of the present research was to investigate and analyze the hunting intentions of medical students for rural grassroots in Gansu and to provide a reference for decision-making on rural health human resource . A questionnaire is the research tool which was used to investigate the views of the senior students from six medical schools , and we studied their employment willingness to rural healthcare institutions .Chi-square test and non-condi-tional logistic regression analyses were used for data analysis .A sample of 600 medical graduates was involved in this investigation.The results of this study show that more than a half (55.6%) of the students would like to work in ru-ral, but only 13.8%of which were “very willing” to work at the rural healthcare institutions .According to the out-comes of this investigation , the number of junior college students who would like to work at the grassroots was 2.3 times the number of the undergraduate students .Medical students whose monthly salary expectations were not high ,with the household registration in rural areas , and having a better understanding of the policy of rural grass-roots em-ployment were more likely to work at the rural healthcare institutions .Based on the findings of this investigation , it can be concluded that the grassroots medical career intention of medical students is not only influenced by its own fac -tors, such as education and household registration , but also the policy of the government , school employment guid-ance and social atmosphere play an important role .The above-mentioned factors should be considered by decision-making and management departments of public healthcare .The departments should introduce a reasonable recruit-ment policy and strengthen the construction of grass-roots medical technology , equipment , and infrastructure , im-prove the grass-roots of employment environment and career development opportunities and strengthen the medical students'employment guidance work to make medical students more willing to work at rural healthcare institutions .

A new molecular method for simultaneously rapid detection and differentiation of Mycobacterium tuberculosis, Mycobacterium bovis, Mycobacterium avium and Mycobacterium paratuberculosis was established by using denaturing high-performance liquid chromatography (DHPLC) combined with multiplex nucleic acid amplification. These 4 important pathogenic mycobacteria were identified by separation of 4 specific PCR-amplified target fragments by DHPLC analysis. A total of 51 Mycobacterium strains and 22 other bacterial species were tested to confirm the specificity of the multiplex PCR-DHPLC assay. The sensitivity of the assay was as low as 10~2-10~3 gene copies. This method rapidly identify the positive clinical samples from human and bovine with higher detection ratio than traditional culture method and was able to identify simultaneously four pathogenic Mycobacterium, which provided a new molecular tool for rapid detection of tuberculosis and paratuberculosis in human and animals.

This study was to investigate the effects of the combination of deoxynivalenol (DON) and zearalenone (ZON) on pigs. Twenty-four weaning piglets were divided into a control group fed a diet free of mycotoxins and a toxin group fed a diet containing 1 mg/kg DON and 250 microgram/kg ZON. The results showed that supplementation of DON and ZON in diets had extensive effects on pigs. More specifically, DON and ZON caused levels of total protein, albumin, and globulin in sera to decrease (p < 0.05) by 14.5%, 6.5% and 11.3%, respectively, and at the same time increased (p < 0.05) the serum enzyme activities of gamma-glutamyltransferase, aspartate aminotransferase and alanine aminotransferase by 72.0%, 32.6% and 36.6%, respectively. In addition, DON and ZON decreased (p < 0.05) the level of anticlassical swine fever antibody titers by 14.8%. Real-time PCR showed that DON and ZON caused the mRNA expression levels of IFN-gamma, TNF-alpha, IL-2, to decrease (p < 0.05) by 36.0%, 29.0% and 35.4%, respectively. Histopathological studies demonstrated that DON and ZON caused abnormalities in the liver, spleen, lymph nodes, uterus, and kidney. The concentrations of DON and ZON used in this study are in line with the published critical values permitted by BML. Our study clearly put the standard and adequacy of safety measures for these toxins into question. The authors suggest that with the increasing availability of cellular and molecular technologies, it is time to revisit the safety standards for toxins in feeds so as to make feeds safer, providing consumers with safer products.
Animal Feed/*analysis ; Animal Nutritional Physiological Phenomena ; Animals ; Diet/veterinary ; Drug Therapy, Combination ; Female ; Swine ; Swine Diseases/blood/*chemically induced/*physiopathology ; Trichothecenes/*administration & dosage/*adverse effects/pharmacology ; Zearalenone/*administration & dosage/*adverse effects/pharmacology