ObjectiveTo explore drug resistance, resistant mechanisms and resistant phenotypes of staphylococcus aureus (SA) isolated from wound secretion to macrolides-lincosamides-streptogramins (MLS). MethodsA retrospective design was used to collect clinical data and antimicrobial resistance profiles of SA in the First Affiliated Hospital and the Second Affiliated Hospital of Fujian Medical University and Anxi County Hospital from June, 2008 to October, 2015. SPSS 19.0 software was used for data analysis. ResultsA total of 127 isolates were included. The distribution of four resistant phenotypes of SA to MLS were all susceptibility(S) type (n=48, 37.8%), ML type (n=41, 32.3%), M/iCR+ type (n=22, 17.3%) and MLS type (n=16, 12.6%), respectively; There were three kinds of phenotypes caused by target changing including ML type, M/iCR+ type and MLS type, respectively. Moreover, no moxicaxin, linezolid or tigecyline resistant strain was detected, while quinolons and tetracyclines showed low-level resistant. ConclusionCompared with the different samples, the resistant phenotypes of SA isolated from wound secretion to MLS are few, and the total resistance ratio is low.
ObjectiveTo detect the in vitro susceptibility of common clinical multidrug-resistant bacteria to tigecycline by disk diffusion (KB), minimum inhibitory concentrations (MIC) test strip (MTS) and Vitek 2 Compact methods, in order to evaluate the accuracy of the three different susceptibility testing methods. MethodsA total of 140 multidrug-resistant isolates (excluding Pseudomonas aeruginosa) were collected retrospectively from West China Hospital between January 2014 and March 2015. The inhibitory zone diameters and MIC of tigecycline were determined by KB, Vitek 2 Compact system and MTS respectively. The results of Vitek 2 Compact system and KB method were compared with that of MTS. ResultsAmong the 140 multidrug-resistant isolates, 119 were Acinetobacter baumannii, and 21 were Enterobacteriaceae. According to the US Food and Drug Administration standards, the sensitivity rates of 119 Acinetobacter baumannii isolates to tigecycline were 88.2%, 85.7%, and 90.8% respectively for KB method, Vitek 2 Compact system and MTS, and those of 21 Enterobacteriaceae were 76.2%, 81.0%, and 81.0%, respectively. ConclusionsTigecycline displays effective in vitro antibacterial activity to clinical common multidrug-resistant bacteria (excluding Pseudomonas aeruginosa), but different susceptibility testing methods have shown different susceptibility rates. For Acinetobacter baumannii, KB method is superior to Vitek 2 Compact system, and for Enterobacteriaceae, Vitek 2 Compact system is superior to KB method.