Objective To study the limitation analysis of Staphylococcus spp Susceptibility Test Kit ATB STAPH 5 from Bi-oMerieux in clinical application and to propose remedy.Methods The coverage area and break point of antibiotics ATB STAPH 5 from BioMerieux were analysed by using CLSI M100-S23 as standard.Results The kit ATB STAPH 5 did not include chloromycetin,oxazolidinones and lipopeptide three antibiotics that were recommend by CLSI.The 16 kinds of antibi-otics break point in the kit ATB STAPH 5 were all not inconsistent or did not contain with the standard of CLSI M100-S23. It may lead to error drug sensitivity tests,false sensitive or false drug resistance.Conclusion Only using this kit ATB STAPH 5 for Staphylococcus spp ,it may occurre errors or mistakes.Other experiments must be corrected before the re-port.

Objective To explore the clinical application of antibiotics Ceftazidime(CAZ) and Cefotetan(CTT)by analysis susceptibility and scatter of the CAZ adn CTT against Escherichia coli(ECO) and Klebsiella pneumoniae(KPN).Methods The drug sensitivity analysis of 1 311 strains of ECO and 898 strains of KPN isolated from 2012 to 2015 and the relationship between CAZ and CTT was analyzed by using the Whonet 5.6 software.Results The resistance rate of ESBL+ KPN to CAZ was 41.2％ and the rate to CTT was 14.1％,the difference was statistically significant(P<0.05).The resistance rate of ESBL+ ECO to CAZ was 34.6％ and the rate to CTT was 1.1％,the difference was statistically significant(P<0.05).The average value of MIC of CAZ was highest in group of ESBL+KPN,it was 6.39 μg/mL.And it was lowest in group of ESBL-KPN,it was 1.37 μg/mL.The average value of MIC of CTT was highest in group of ESBL+KPN,it was 6.8 μg/mL.And the lowest was in group of ESBL-KPN.The range of MIC of CAZ was 1-64 μg/mL,and the range of CTT was 4-64 μg/mL in all groups.The cross sensitivity of CAZ and CTT was more than 90.0％.The cross resistance was less than 5.0％.The cross sensitivity of CAZ and CTT was less than 70.0％ in ESBL+ group.And the cross resistance was up to 13.4％.Conclusion The cross resistance and cross sensitivity of the two antibiotics is very important in guiding clinical antibiotic selection or replacement.

Staphylococcus aureus is a Gram-positive bacterium with strong pathogenicity. With the widespread use of antibiotics， its multi-drug resistance has gradually increased. Among them， methicillin-resistant S. aureus （MRSA） is one of the main pathogens of hospital and community infections. Antimicrobial peptides are short-chain peptides with good antibacterial effects and low drug resistance， which have been widely studied in recent years. This study summarizes the mechanism of action of antimicrobial peptides and related study on antimicrobial peptides against MRSA from different sources. It is found that the mechanisms of action of antimicrobial peptides include targeting bacterial cell membranes， bacterial cells， and bacterial cell walls， etc. Besides isolating antimicrobial peptides with anti-MRSA activity from animals， plants， and microorganisms， antimicrobial peptides can also be obtained through synthetic methods. Among them， GHa-derived peptides from animal sources， Ib-AMP4 from plant sources， Ph-SA from microbial sources， the synthetic peptide LLKLLLKLL-NH2， and so on， due to their effective antibacterial activity， rapid bactericidal speed， and low toxicity， are promising candidates for anti-MRSA drugs.