Drug resistance and distribution characteristics of Gram-positive bacteria in
Western China
Guo Su-fang1, Wang Jun-rui1, Han Yan-qiu1, Yu Hua2, Zhang Hua3, Ji Ping4, Shan Bin5, A Xiang-ren6, Lu Wei-Ping7,
Jia Wei8, Wei Lian-hua9 and Xu Xiu-li10
Abstract：Abstract Objective To understand the sensitivity and drug resistance of clinically isolated Gram-positive
bacteria against commonly used antibacterial drugs agents in Western China. Methods Gram-positive bacteria
isolated from 10 hospitals in Western China were tested for antimicrobial susceptibility by Kirby-Bauer test or automated instrumentation. Breakpoint standard of CLSI 2017 M100-s27th was recommended to determinate results.
Result A total of 16,558 strains and 19,263 strains of clinically isolated Gram-positive bacteria were collected
from the above hospitals in 2016 and 2017. The top 3 isolates of positive bacteria were Staphylococcus aureus,
Enterococcus faecium and Streptococcus pneumoniae. The isolation rates of methicillin-resistant Staphylococcus
aureus (MRSA) in 2016 and 2017 were 34.9% and 32.8%, respectively. The resistance rate of MRSA to most
tested drugs was significantly higher than that of methicillin sensitive Staphylococcus aureus(MSSA). Vancomycin,
linezolid and teicoplanin resistant strains were not found. The resistance rate of Enterococcus faecalis to most tested
antibacterial was significantly lower than that of Enterococcus faecium, and there were a few vancomycin resistant
strains was found in both. Group A and group B had higher resistance rates to erythromycin and clindamycin, group
B Streptococcus also had higher resistance rate to levofloxacin, and had better sensitivity to other tested antibacterial
drugs. There was high resistance rate of erythromycin, clindamycin and cotrimoxazole in Streptococcus pneumoniae
non-meningitis strain. There were no vancomycin and linezolid resistant strains were found. Conclusion MRSA
detection rate has a downward trend; vancomycin-resistant enterococci isolation rate is at a low level; vancomycin,
linezolid, and teicoplanin have good antibacterial activity against Gram-positive cocci. There are differences in drug
resistance of Gram-positive bacteria in different regions, and paid attention on drug resistance monitoring and rational
application of antimicrobial drugs.
