Detection and multi⁃locus sequence typing of low⁃affinity penicillin⁃binding protein of β⁃lactam resistant Enterococcus faecalis / 安徽医科大学学报

ABSTRACT

Objective @# To detect the low⁃affinity penicillin⁃binding protein drug resistance , pbp4 gene , and multi⁃ locus sequence typing (MLST) of clinically isolated E. faecalis .@*Methods @#78 clinical isolates of E. faecalis were collected , and their drug resistance was detected by automated instruments ; the mutation of pbp4 gene mutation was analyzed by PCR amplification and MLST . @*Results @# 78 strains of E. faecalis were highly resistant to ciprofloxacin , levofloxacin , rifampicin , erythromycin , tetracycline and high concentration of gentamicin , and were resistant to penicillin and gentamicin . The ampicillin resistance rate was 10. 3% , and no strains were found to be resistant to nitrofurantoin , vancomycin , teicoplanin and linezolid ; 8 strains of 78 E. faecalis had amplified TEM genes , and all of them were resistant to penicillin and ampicillin resistance , with a positive rate of 10. 3% ; the allelic profiles and sequence types of 78 strains of E. faecalis which were divided into 16 sequence types , of which ST179 and ST16 were the most , with 21 and 21 strains , respectively . 20 strains , accounting for 26. 9% and 25 . 6% , the rest were ST6 type 8 strains (10. 3% ) , ST4 type 7 strains (9 . 0% ) , ST585 type 6 strains (7 . 7% ) , ST480 type 4 strains (5 . 1% ) , ST28 strains 3 strains (3 . 8% ) of the ST type were detected , and only 1 strain was detected for the oth⁃ er ST types . The analysis of the relationship between ST types and drug resistance showed that E. faecalis with the same ST type had similar drug resistance profiles . @*Conclusion @#The resistance mechanism of E. faecalis to β ⁃lactam antibiotics is mainly caused by the production of β⁃lactamase mediated by TEM gene , which is not necessarily related to the mutation of pbp4 gene . The isolates of E. faecalis are mainly CC16 ( including ST16 and ST179) clones and drug resistance is serious . It is necessary to guide clinical medication and strengthen nosocomial infection monitoring according to its characteristics .