Objective To investigate the distribution and
antibiotic resistance of clinical
Enterobacter isolates .
Methods A total of 3 031 clinical
strains of
Enterobacter were collected from 15
hospitals from January 1 through December 31 , 2012 . Antimicrobial susceptibility testing was performed with Kirby-Bauer or
minimum inhibitory concentration method .The results were analyzed according to CLSI 2012 breakpoints .Results
Enterobacter cloacae and
Enterobacter aerogenes accounted for 73 .0% (2 212/3 031) and 23 .9% (725/3 031) of all the
Enterobacter strains .The isolates of other
Enterobacter species accounted for 3 .1% (94/3 031 ) . The main source of the isolates was
respiratory tract specimen ,
accounting for 53 .2% (1 612/3 031) .Most (> 89% ) of the
Enterobacter strains were resistant to
cefazolin and
cefoxitin . Generally ,54 .4% ,47 .5% and 34 .3% of the
strains were resistant to
cefuroxime ,
cefotaxime and cefazidime ,respectively . About 6 .6% to 26 .3% of the
strains were resistant to
amikacin ,
gentamicin ,
piperacillin-
tazobactam ,
cefepime ,
cefoperazone-
sulbactam ,
ciprofloxacin and
trimethoprim-sulfamethoxazole .
Imipenem ,
meropenem and
ertapenem showed the highest activity , to which only 3 .5% ,3 .7% and 10 .3% of the
strains were resistant ,respectively .About 8 .9% (269/3 031) of the
strains were resistant to at least
imipenem ,
meropenem or
ertapenem .Four
Enterobacter strains were extensive-
drug resistant (XDR) .Conclusions The
prevalence of
antibiotic resistance in
Enterobacter isolates decreased slightly in 2012 compared to the data in 2011 ,but the situation is still very serious .We should continue to take effective
measures to control the resistant
strains .