Objective:To determine the clinical implication of and intestinal carriage with methicillin resistant Staphylococcus aureus(MRSA) and extended spectrumβ-lactamase(ESBL)-producing Enterobacteriacae.Methods: A total of...Objective:To determine the clinical implication of and intestinal carriage with methicillin resistant Staphylococcus aureus(MRSA) and extended spectrumβ-lactamase(ESBL)-producing Enterobacteriacae.Methods: A total of 180 stool specimens were screened for MRSA and ESBL-producing enterobacteria.Identification of ESBL- producing Enterobacteriacae was done by MicroScan Walk Away 96 system(Dade Behring Inc.,West Sacramento,CA 95691,USA ) and confirmation by double-disc synergy test.MRSA was identified by disc diffusion using 30μg cefoxitin disc and the MicroScan.Results:The rate of fecal MRSA carriage was 7.8% (14/180),35.7%(5 /14) were recovered from surgical wards.Three patients(21,4%) had MRSA recovered from other body sites,and 2(14.2%) had in addition ESBL -producing Escherichia coli(E.coli) and Klebsiella pneumoniae(K.pneumoniae) respectively.Four(28.5%) patients with MRSA fical carriage died. MRSA fecal carriage was recovered from both inpatients and outpatients.Four(2.2%) cases carried ESBL-producing Enterobacteriacae in feces.Three(75%) were from intensive care unit(ICU).One patient had both ESBL-producing E.coli and K.pneumoniae from stool as well as E.coli from tracheal aspirate.Two ICU patients with fecal ESBL died.Conclusion:Fecal screening for MRSA and ESBL of all patients at high risk admitted to different hospital wards and ICUs and implementing infection control measures were recommended.展开更多
Bovine mastitis caused by Staphylococcus aureus is difficult to treat because of increasing resistance against antibiotics, especially penicillin. β-Lactamase and biofilm are responsible for penicillin resistance of ...Bovine mastitis caused by Staphylococcus aureus is difficult to treat because of increasing resistance against antibiotics, especially penicillin. β-Lactamase and biofilm are responsible for penicillin resistance of S. aureus. The aim of this study was to investigate the β-lactamase activity and biofilm formation capacity of 37 penicillin-resistant S. aureus strains （35 were blaZ positive and 2 were blaZ negative） from bovine mastitis in Gansu Province, China, as well as to measure the intercellular adhesion genes icaA and icaD of these strains. β-Lactamase Test Kit was used to determine the β-lactamase activity, biofilm formation was tested by semi-quantitative adherence assay method. Moreover, the presence of icaA and icaD were measured by PCR. A total of 32 penicillin-resistant S. aureus strains, including the two blaZ-negative strains, were identified as β-lactamase producers. All tested S. aureus isolates produced biofilm in the microtiter plate assay. Meanwhile, all these strains were PCR-positive for the ica locus, icaA and icaD. The study indicated high prevalence of β-lactamase activity, biofilm-forming capacity, and the ica genes among the penicillin-resistant S. aureus isolates, and implied that S. aureus resistant to penicillin was attributed to multiple mechanisms.展开更多
BACKGROUND In the United States,Staphylococcus aureus(S.aureus)kills tens of thousands of individuals each year and the formation of a biofilm contributes to lethality.Biofilm-associated infections are hard to treat o...BACKGROUND In the United States,Staphylococcus aureus(S.aureus)kills tens of thousands of individuals each year and the formation of a biofilm contributes to lethality.Biofilm-associated infections are hard to treat once the biofilm has formed.A new stilbene drug,labeled SK-03-92,was shown to kill S.aureus and affected transcription of two genes tied to a putative two-component system(TCS)we have named brpR(biofilm regulating protein regulator)and brpS(biofilm regulating protein sensor).AIM To determine if BrpR and BrpS regulate biofilm formation,brpR and brpS mutants were assessed using biofilm assays compared to wild-type S.aureus.METHODS A combination of biofilm and quantitative real-time-polymerase chain reaction assays were used.In addition,bioinformatic software tools were also utilized.RESULTS Significantly more biofilm was created in the brpR and brpS mutants vs wild-type cells.Quantitative real-time polymerase chain reactions showed the brpS mutant had differences in transcription of biofilm associated genes that were eight-fold higher for srtA,two-fold lower for lrgA,and 1.6-fold higher for cidA compared to wild-type.Bioinformatic analysis demonstrated that the S.aureus brpR/brpS TCS had homology to streptococcal late-stage competence proteins involved in celldeath,increased biofilm production,and the development of persister cells.CONCLUSION Our study suggests that brpR/brpS is a TCS that may repress S.aureus biofilm production and be linked to late-stage competence in S.aureus.展开更多
【目的】探讨枸杞槲皮素对金黄色葡萄球菌产生的β-内酰胺酶的抑制作用机制,为临床研发β-内酰胺酶抑制剂提供基础依据。【方法】通过青霉素抑菌圈边缘试验筛选产β-内酰胺酶阳性菌株,通过药敏纸片法检测阳性菌株在32、64、128μg/mL枸...【目的】探讨枸杞槲皮素对金黄色葡萄球菌产生的β-内酰胺酶的抑制作用机制,为临床研发β-内酰胺酶抑制剂提供基础依据。【方法】通过青霉素抑菌圈边缘试验筛选产β-内酰胺酶阳性菌株,通过药敏纸片法检测阳性菌株在32、64、128μg/mL枸杞槲皮素作用下对青霉素的敏感性变化;借助多功能酶标仪检测在32、64、128、256μg/mL枸杞槲皮素处理下青霉素含量的变化,并以此来评估枸杞槲皮素对β-内酰胺酶合成及在64、128、256μg/mL枸杞槲皮素作用下对β-内酰胺酶活性的影响。通过AutoDockTools 1.5.6软件对枸杞槲皮素与BlaZ蛋白进行分子对接,采用Discovery Studio 2019 Client软件对分子对接结果进行可视化分析。【结果】从36株金黄色葡萄球菌中共筛选出23株产β-内酰胺酶阳性菌株。药敏纸片结果表明,随着枸杞槲皮素浓度的升高,阳性菌株对青霉素的敏感性增加。多功能酶标仪检测结果表明,枸杞槲皮素可以抑制β-内酰胺酶的合成,并显著抑制β-内酰胺酶的活性(P<0.05)。分子对接结果表明,枸杞槲皮素通过与BlaZ蛋白Ω-loop区域内的保守残基Asn161以氢键结合,影响BlaZ蛋白与β-内酰胺类抗生素的结合。【结论】枸杞槲皮素可以减少β-内酰胺酶的合成,还可通过降低β-内酰胺酶的活性增强青霉素的抑菌作用,具有作为β-内酰胺酶抑制剂的潜在活性,为后续开发新型β-内酰胺酶抑制剂提供了参考依据。展开更多
目的:比较头孢硝噻吩液体(Cefinase)、头孢硝噻吩纸片(Dryslide)、三叶草实验(Cloverleaf)、青霉素边缘实验(Penicillin disk zone edge)检测金黄色葡萄球菌β-内酰胺酶的敏感性和特异性。方法:分别用Cefinase,Dryslide,Cloverleaf,Peni...目的:比较头孢硝噻吩液体(Cefinase)、头孢硝噻吩纸片(Dryslide)、三叶草实验(Cloverleaf)、青霉素边缘实验(Penicillin disk zone edge)检测金黄色葡萄球菌β-内酰胺酶的敏感性和特异性。方法:分别用Cefinase,Dryslide,Cloverleaf,Penicillin disk zone edge检测金黄色葡萄球菌β-内酰胺酶。结果:4种方法敏感度分别为83%、66%、91%、91%。特异度分别为100%、97%、100%、100%。结论:4种方法在检测应用上都能为临床提供可靠的结果,但Cloverleaf和Penicillin disk zone edge检测β-内酰胺酶的试验较敏感,在操作上用头孢硝噻吩纸片法更能被实验室所接受。展开更多
文摘Objective:To determine the clinical implication of and intestinal carriage with methicillin resistant Staphylococcus aureus(MRSA) and extended spectrumβ-lactamase(ESBL)-producing Enterobacteriacae.Methods: A total of 180 stool specimens were screened for MRSA and ESBL-producing enterobacteria.Identification of ESBL- producing Enterobacteriacae was done by MicroScan Walk Away 96 system(Dade Behring Inc.,West Sacramento,CA 95691,USA ) and confirmation by double-disc synergy test.MRSA was identified by disc diffusion using 30μg cefoxitin disc and the MicroScan.Results:The rate of fecal MRSA carriage was 7.8% (14/180),35.7%(5 /14) were recovered from surgical wards.Three patients(21,4%) had MRSA recovered from other body sites,and 2(14.2%) had in addition ESBL -producing Escherichia coli(E.coli) and Klebsiella pneumoniae(K.pneumoniae) respectively.Four(28.5%) patients with MRSA fical carriage died. MRSA fecal carriage was recovered from both inpatients and outpatients.Four(2.2%) cases carried ESBL-producing Enterobacteriacae in feces.Three(75%) were from intensive care unit(ICU).One patient had both ESBL-producing E.coli and K.pneumoniae from stool as well as E.coli from tracheal aspirate.Two ICU patients with fecal ESBL died.Conclusion:Fecal screening for MRSA and ESBL of all patients at high risk admitted to different hospital wards and ICUs and implementing infection control measures were recommended.
基金supported by the Central Public-Interest Scientific Institution Basal Research Fund,China(1610322015007)the Key Technologies R&D Program of China during the 12th Five-year Plan period(2012BAD12B03)the Natural Science Foundation of Gansu Province,China(145RJYA311)
文摘Bovine mastitis caused by Staphylococcus aureus is difficult to treat because of increasing resistance against antibiotics, especially penicillin. β-Lactamase and biofilm are responsible for penicillin resistance of S. aureus. The aim of this study was to investigate the β-lactamase activity and biofilm formation capacity of 37 penicillin-resistant S. aureus strains （35 were blaZ positive and 2 were blaZ negative） from bovine mastitis in Gansu Province, China, as well as to measure the intercellular adhesion genes icaA and icaD of these strains. β-Lactamase Test Kit was used to determine the β-lactamase activity, biofilm formation was tested by semi-quantitative adherence assay method. Moreover, the presence of icaA and icaD were measured by PCR. A total of 32 penicillin-resistant S. aureus strains, including the two blaZ-negative strains, were identified as β-lactamase producers. All tested S. aureus isolates produced biofilm in the microtiter plate assay. Meanwhile, all these strains were PCR-positive for the ica locus, icaA and icaD. The study indicated high prevalence of β-lactamase activity, biofilm-forming capacity, and the ica genes among the penicillin-resistant S. aureus isolates, and implied that S. aureus resistant to penicillin was attributed to multiple mechanisms.
文摘BACKGROUND In the United States,Staphylococcus aureus(S.aureus)kills tens of thousands of individuals each year and the formation of a biofilm contributes to lethality.Biofilm-associated infections are hard to treat once the biofilm has formed.A new stilbene drug,labeled SK-03-92,was shown to kill S.aureus and affected transcription of two genes tied to a putative two-component system(TCS)we have named brpR(biofilm regulating protein regulator)and brpS(biofilm regulating protein sensor).AIM To determine if BrpR and BrpS regulate biofilm formation,brpR and brpS mutants were assessed using biofilm assays compared to wild-type S.aureus.METHODS A combination of biofilm and quantitative real-time-polymerase chain reaction assays were used.In addition,bioinformatic software tools were also utilized.RESULTS Significantly more biofilm was created in the brpR and brpS mutants vs wild-type cells.Quantitative real-time polymerase chain reactions showed the brpS mutant had differences in transcription of biofilm associated genes that were eight-fold higher for srtA,two-fold lower for lrgA,and 1.6-fold higher for cidA compared to wild-type.Bioinformatic analysis demonstrated that the S.aureus brpR/brpS TCS had homology to streptococcal late-stage competence proteins involved in celldeath,increased biofilm production,and the development of persister cells.CONCLUSION Our study suggests that brpR/brpS is a TCS that may repress S.aureus biofilm production and be linked to late-stage competence in S.aureus.
文摘【目的】探讨枸杞槲皮素对金黄色葡萄球菌产生的β-内酰胺酶的抑制作用机制,为临床研发β-内酰胺酶抑制剂提供基础依据。【方法】通过青霉素抑菌圈边缘试验筛选产β-内酰胺酶阳性菌株,通过药敏纸片法检测阳性菌株在32、64、128μg/mL枸杞槲皮素作用下对青霉素的敏感性变化;借助多功能酶标仪检测在32、64、128、256μg/mL枸杞槲皮素处理下青霉素含量的变化,并以此来评估枸杞槲皮素对β-内酰胺酶合成及在64、128、256μg/mL枸杞槲皮素作用下对β-内酰胺酶活性的影响。通过AutoDockTools 1.5.6软件对枸杞槲皮素与BlaZ蛋白进行分子对接,采用Discovery Studio 2019 Client软件对分子对接结果进行可视化分析。【结果】从36株金黄色葡萄球菌中共筛选出23株产β-内酰胺酶阳性菌株。药敏纸片结果表明,随着枸杞槲皮素浓度的升高,阳性菌株对青霉素的敏感性增加。多功能酶标仪检测结果表明,枸杞槲皮素可以抑制β-内酰胺酶的合成,并显著抑制β-内酰胺酶的活性(P<0.05)。分子对接结果表明,枸杞槲皮素通过与BlaZ蛋白Ω-loop区域内的保守残基Asn161以氢键结合,影响BlaZ蛋白与β-内酰胺类抗生素的结合。【结论】枸杞槲皮素可以减少β-内酰胺酶的合成,还可通过降低β-内酰胺酶的活性增强青霉素的抑菌作用,具有作为β-内酰胺酶抑制剂的潜在活性,为后续开发新型β-内酰胺酶抑制剂提供了参考依据。
文摘目的:比较头孢硝噻吩液体(Cefinase)、头孢硝噻吩纸片(Dryslide)、三叶草实验(Cloverleaf)、青霉素边缘实验(Penicillin disk zone edge)检测金黄色葡萄球菌β-内酰胺酶的敏感性和特异性。方法:分别用Cefinase,Dryslide,Cloverleaf,Penicillin disk zone edge检测金黄色葡萄球菌β-内酰胺酶。结果:4种方法敏感度分别为83%、66%、91%、91%。特异度分别为100%、97%、100%、100%。结论:4种方法在检测应用上都能为临床提供可靠的结果,但Cloverleaf和Penicillin disk zone edge检测β-内酰胺酶的试验较敏感,在操作上用头孢硝噻吩纸片法更能被实验室所接受。
