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The aim of this study is to investigate antibiotic resistance and molecular epidemiology characteristics of methicillin-resistant Staphylococcus aureus (MRSA) in Shenzhen area.We collected 428 Staphylococcus aureus isolates from eight hospitals in Shenzhen in 2012.According to the results of minimum inhibitory concentration (MIC) to cefoxitin,26.2％ of Staphylococcus aureus isolates (112/428) were identified as MRSA.The MIC of 10 antimicrobial agents was determined by agar dilution method.Panton-Valentine leucocidin(PVL) was detected by polymerase chain reaction(PCR).Positive strains of PVL were detected by multilocus sequence typing(MLST).Among the 112 strains,the resistance rates to trimethoprim-sulfamethoxazole,moxifloxacin,ciprofloxacin,gentamicin,erythromycin,clindamycin and tetracycline were 4.46％,12.50％,16.96％,19.64％,46.42％,25.00％ and 26.79％ respectively.No isolates resistant to vancomycin,linezolid and teicoplanin were found.Among the 112 strains,there were 13 (11.61％) strains carried PVL gene.There were no significant differences in the resistance rates of PVL positive strains and negative strains to 10 kinds of antimicrobial agents.Among the 13 strains carried PVL gene,7 kinds of old sequences and 1 kind of new sequence type were found by MLST.ST338 and ST25 were the most common type.All the data indicate that surveillance of MRSA in Shenzhen has a distinct genetic background from other regions.
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<p><b>OBJECTIVE</b>To analyze the quality characteristics of human spermatozoa with hyaluronic acid (HA) receptors and search for a new indicator for the assessment of sperm quality.</p><p><b>METHODS</b>Using sperm-HA binding assay with HA-coated slides, we determined the binding rate of motile sperm with HA receptors and analyzed its correlation with routine semen parameters, sperm membrane function, sperm fertilizing function and diminished/arrested sperm maturation.</p><p><b>RESULTS</b>The motile sperm with HA binding sites in the acrosomal region showed significantly higher acrosomal integrity ([95.4 +/- 3.9]%) and mitochondrial membrane potential (MMP) ([97.8 +/- 2.1]%) than those in the initial semen ([68.8 +/- 6.2]% and [72.8 +/- 7.4]%) (P < 0.01). The sperm-HA binding scores were correlated mildly with many routine semen parameters (r = 0.195-0.268, P < 0.05), positively with the acrosome reaction level after ionophore challenge (r = 0.666, P < 0.01) and normal sperm morphology (r = 0.417, P < 0.01), and negatively with sperm nucleoprotein immaturation (r = -0.266, P < 0.01), DNA fragmentation (r = -0. 308, P < 0.01) and excessive residual cytoplasm (r = -0.218, P < 0.05).</p><p><b>CONCLUSION</b>Sperm with HA receptors in the acrosomal region exhibit significant advantages in plasma membrane structure, fertilizing potential and maturation. The sperm-HA binding assay, which is based on a relationship between sperm receptors for zona pellucida and HA, is likely to become a new independent indicator for assessing the multiple qualities of spermatozoa.</p>
Subject(s)
Humans , Male , Acrosome , Metabolism , Hyaluronan Receptors , Metabolism , Hyaluronic Acid , Spermatozoa , Cell Biology , Metabolism , PhysiologyABSTRACT
Objective To investigate the prevalence and molecular characteristics of the extended -spectrum β-lactamase ( ESBL) and AmpC enzyme-producing Proteus mirabilis ( P.mirabilis) strains isola-ted in Shenzhen People′s Hospital.Methods The production of ESBLs and AmpC enzymes by P.mirabilis isolates were detected by a screening and confirmatory test for ESBLs and AmpC disk test , respectively .The PCR assays followed by DNA sequencing of the products were employed to analyze the multiple genes inclu -ding the ESBLs genes, AmpC genes, insertion sequences (ISs) upstream of the ESBLs or AmpC genes, plasmid -mediated quinolone resistance ( PMQR ) determinants , quinolone resistance-determining region (QRDR) genes , the integrase genes, and class1 integron cassette.The epidemiological analysis of the iso-lates was performed by pulsed field gel electrophoresis .Results There were 130 P.mirabilis clinical iso-lates collected from Shenzhen People′s Hospital in China during the year 2004 to 2010.Among them, 13 isolates (10%) produced ESBLs, that accounted for 0%-9.1%in the year 2004-2009 and up to 29.4%in 2010, and 3 isolates (2.3%) produced AmpC enzymes.The predominant genotype of ESBLs -producing isolateswas b al CTX-M-14(n=7), followed by blaCTX-M-65(n=3), blaCTX-M-55(n=1), blaCTX-M-24(n=1) and blaPER-1 (n =1).The clinical isolate of PER-1-producing P.mirabilis was reported for the first time in China.Twoisolates carried an AmpC β-lactamase gene of blaCMY-2 and one isolate carried an unidentified AmpC gene .ISEcp1 located upstream of blaCTX-M and blaCMY-2 were detected in 91.7% (11/12) of CTX-M-producing isolatesand one CMY-2-producing isolate, respectively.ISPa12 was present upstream of blaPER-1 in one studiedisolate.Approximately 66.7% (10/15) of ESBL and /or AmpC-producing isolates harbored PMQR genes including2 carrying qnrD, 5 carrying aac-Ib-cr and 3 carrying both qnrD and aac-Ib-cr.Twelve ESBL and /orAmpC-producers with high level of resistance to ciprofloxacin carried the similar mutation profiles of S 83I inGyrA, S80I or S80R in ParC and among them, six strains showed E466D mutation in GyrB.Approximately86.7% (13/15) of ESBL and/or AmpC-producing isolates carried class 1 integron.Fourteen PFGE typeswere observed among 15 ESBL and/or AmpC-producers.Conclusion The prevalence of CTX-M β-lactamasesin P.mirabilis isolates contributed to the increased resistance to extended -spectrum cephalosporins.The qnrD and/or aac-Ib-cr genes were detected among the most of ESBL and /or AmpC-producing P.mirabilis clinical isolates.
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Objective To evaluate the capability of multilocus variable-number tandem-repeat ( VNTR) analysis ( MLVA) and pulsed-field gel electrophoresis ( PFGE) for genotyping Salmonella enterica serovar Typhi (S.Typhi) isolates.Methods Five polymorphic VNTRs (SAL02,SAL11,SAL16,SAL20, and TR4699 ) that were observed in S.Typhi strains from previous studies were selected to establish MLVA . Twenty-one epidemiologically unrelated S.Typhi strains that were isolated from Shenzhen ,China from 2002 to 2007 were genotyped by the established MLVA , and the results were compared with those by PFGE . Results The Simpson′s index of diversity ( D value ) for all five different VNTRs ranged from 0.838 to 0.943 .A total of 19 MLVA profiles and 19 PFGE profiles were found , respectively .The D value for both MLVA and PFGE were 0.99 and the test results from two analyses were identical .Conclusion The five polymorphic VNTRs analysis could be used as an alternative typing scheme for epidemiologic investigation of S.Typhi infection .