The Study on the Drug Resistance and Genofyping of Aminoglycoside-modifying Enzymes in ESBLs Positive Escherichia Coli
- VernacularTitle:产ESBLs大肠杆菌的耐药性及氨基糖苷类修饰酶基因研究
- Author:
Lianhua YU
;
Chunqin PAN
;
Dakang HU
;
Chibo LIU
;
Dongguo WANG
- Publication Type:Journal Article
- Keywords:
Escherichia coli;
Drug resistance;
Aminoglycoside-modifying enzymes
- From:
Journal of Medical Research
2006;0(12):-
- CountryChina
- Language:Chinese
-
Abstract:
Objective To investigate drug resistance,especially the resistance to aminoglycoside and the prevalence of the genes for aminoglycoside-modifying enzymes in Escherichia coli producing ESBLs.Methods VITEK-32 GNI+ cards and K-B methods were used to identify E.coli and detect the resistance to 18 kinds of antibiotics such as aminoglycoside and ?-lactams respectively in E.coli isolated from our hospital from January to December,2006.PCR method was used to detect the genes for aminoglycoside-modifying enzymes such as aac(3)-Ⅰ,aac(3)-Ⅱ,aac(6')-Ⅰb,aac(6')-Ⅱ,ant(3″)-Ⅰ and ant(2″)-Ⅰ in those 17 strains producing ESBLs.Results Resistance rates were 100.0%,100.0%,41.6%,100.0%,69.5%,30.5%,98.2%,81.0%,81.0%,79.6%,79.2%,34.8%,15.4%,7.1%,7.9%,5.4% and 81.0% for ampicillin,ampicillin/sulbactam,aztreonam,cefazolin,cefepime,ceftazidime,ceftriaxone,ciprofloxacin,levofloxacin,gentamicin,tobramycin,amikacin,cifoxitin,nitrofurantoin,piperacillin/tazobactam,cefoperazone/sulbactam and co-trimoxazole respectively in E.coli producing ESBLs.No drug-resistant strain imepenem was found.Positive rate was 46.4% for ESBLs.Resistance rates were 52.9%(9/17),100.0%(17/17) and 100%(17/17) for amikacin,gentamycin and tobmycin respectively in those 17 strains producing ESBLs.The most genotype for aminoglycoside-modifying enzymes was aac(3)-Ⅱ(94.1%),the second was aac(6')-Ⅰb(35.3%).The positive rates of aac(3″)-Ⅰ and ant(2″)-Ⅰ were 11.8% and 5.9% respectively.of them,one strain was resistant to aminoglycoside on phenotype,but no genes mentioned above was detected.4strains were classical on genotype,one with aac(6')-Ⅰb-Cr,the other one with a new subtype among the 6 strains of E.coli with aac(6')-Ⅰb.Conclusions Drug resistance in E.coli is rather serious.Typically,E.coli producing ESBLs shows multi-drug resistance.Positive rate for aac(3)-Ⅱ takes the first place,followed by aac(6')-Ⅰb among the genes for aminoglycoside-modifying enzymes.Aac(3″)-Ⅰand ant(2″)-Ⅰ show both lower positive rates.Aac(3)-Ⅰ and aac(6')-Ⅱ were not found.There exist at least 3 sub-types of aac(6')-Ⅰb,one kind of gene for aminoglycoside-modifying enzymes in strains of E.coli.Among those sub-types,the classical type is the main,accompanied by aac(6')-Ⅰb-Cr and its new sub-type.
