Abstract：Abstract Objective To analyze the antibiotic resistance and distribution characteristics of bacterial strains
isolated from geriatric patients in 10 hospitals across Western China from 2016 to 2017. Methods Bacterial
susceptibility testing was carried out according to a unified protocol using the Kirby-Bauer method and automated
systems. Results were analyzed according to the Clinical and Laboratory Standards Institute (CLSI) 2017 standards.
Results A total of 121,374 clinical isolates were analyzed from January 2016 to December 2017. The proportion of
the strains isolated from geriatric patients was 34.1%, of which Gram positive bacteria were 9,499 strains, accounting
for 22.9%, and Gram negative bacteria were 31,949 strains, accounting for 77.1%, respectively. Methicillin-resistant
Staphylococcus aureus (MRSA) and methicillin-resistant coagulase negative staphylococci (MRCNS) accounted
for 37.1% and 79.3%, respectively. No Staphylococcus strains were found resistant to vancomycin, teicoplanin and
linezolid. In Enterococcus spp, the resistance rates of Enterococcus faecium strains to most tested drugs (except
tetracycline, clindamycin and linezolid) were significantly higher than those of Enterococcus faecalis. Less than 3%
of these strains were resistant to vancomycin, teicoplanin and linezolid. The strains of Enterobacteriaceae were still
highly susceptible to carbapenems (<10% resistant). About 7.1% and 9.9% of Klebsiella pneumoniae were resistant to
imipenem and meropenem, respectively. Resistant rates showed increasing compared with the data of year 2011. About
18.9% and 17.8% of the Pseudomonas aeruginosa strains were resistant to imipenem and meropenem, respectively.
More than 60% of the Acinetobacter baumannii strains were resistant to imipenem and meropenem, which was higher
than the average national level. Conclusions The antibiotic resistance and distribution characteristics of clinical
isolates from geriatric patients were different from average national levels during the same period. Our study suggests
that bacterial resistance surveillance for the clinical isolates from geriatric patients is very important for rational
antimicrobial therapy.
