Abstract:
OBJECTIVE To understand the detection rate drug resistance and resistant genes of the carbapenems-resistant Enterobacteriaceae (CRE).
METHODS CRE positive strains and related clinical data were collected from the medical unit of bacterial resistance monitoring in Dongguan area from Jan. 2015 to Mar. 2016. Strains were identified by VITEK-2-Compact and corresponding drug sensitivity results were reviewed. The positive strains in the preliminary screening were conducted with modified Hodge test to verify the phenotype of the carbapenems. The polymerase chain reaction was adopted to detect the resistant genes carried by the bacteria among the re-checked CRE strains.
RESULTS Totally 45 cases of CRE were detected,with the overall detection rate of 0.28% (45/13137 strains). The detection rate of
Klebsiella pneumoniae was 0.44% (17/3881 strains), that of
Escherichia coli was 0.08% (7/8599 strains), that of
Enterobacter cloacae was 1.84% (13/694 strains), and that of other enteric bacilli was 0.27% (8/2963 strains). The detection rate of CRE in
Escherichia coli was low. The CRE isolation rates of sputum and bile were respectively 0.49% (18/3684 strains) and 1.27% (3/237 strains), which had significant difference with the overall detection rate of CRE (
P<0.05). The drug sensitivity analysis of 45 strains of CRE showed that imipenem resistant rate was 100%, and meropenem resistant rate was 82.22%. Only amikacin resistant rate was lower than 30.00% (15.56%), tobramycin resistant rate was lower than 40.00% (31.11%), and sulfamethoxazole/trimethoprim resistant rate was 40.00%~50.00%. The drug resistant rates to widely used fluoroquinolones and praziquantel/tazobactam were more than 50.00%, and to the third generation of cephalosporin and its enzyme inhibitor were more than 70.00%. The 7 strains of CRE carbapenemase gene amplification sent to be identified by microbiological laboratory were positive, among which 1 case was IMP-4 positive, 6 cases were NDM-6 positive, and 1 case had co-existence of NDM-6 and CTX multi-gene positive.
CONCLUSION The detection rate of CRE is not high in Dongguan area, and the NDM-6 resistant gene is firstly detected in this area, which is rare in other areas in China and has great difference from the resistant genes a few years ago. We should strengthen the supervision of antibiotics and pay attention to the implementation of the prevention and control measures of hospital infection.