Repressor SmeT of Efflux Pump SmeDEF in Stenotrophomonas maltophilia
- VernacularTitle:嗜麦芽寡养单胞菌临床株多重耐药外排泵SmeDEF调控基因smeT的序列分析
- Author:
Erlin SUN
;
Shiduo SONG
;
Wei QI
;
Yubao WANG
- Publication Type:Journal Article
- Keywords:
Stenotrophomonas maltophilia;
Multiple resistance;
Efflux pump;
Repressor
- From:
Chinese Journal of Nosocomiology
2006;0(02):-
- CountryChina
- Language:Chinese
-
Abstract:
OBJECTIVE To investigate the repressor SmeT and other sequences of efflux pump SmeDEF in the clinic isolates of Stenotrophomonas maltophilia to involve in antibiotic resistance. METHODS The mRNA level of smeD examined the resistance profile of the clinical strains to antimicrobials was by agar dilution and their reaction to pump inhibitor was investigated by RT-PCR,and the smeD-smeT fragment was amplified by PCR,and then sequenced.Adding poly(A) to 3′ end of RNA,applying 3′RACE,nested PCR,then sequence-analysis. RESULTS The amino acid sequences of the forepart of SmeT were conservative in all the 7 strains.In antibiotic-resistant strains with positive reaction to pump inhibitor,the intergenic sequences of smeD-smeT were different from those in sensitive ones.The variations in(-165 to-82)nt of smeT and several nucleic acids before the start codon of smeT,possibly involved in antimicrobial resistance.All isolates didn′t have Leu166Gln mutation within the SmeT protein of D457R,which was reported possibly associated with antibiotic resistance.The resistant strains with efflux positively inhibited had Asp218Glu substitution,different from the negatively-inhibited ones. CONCLUSIONS The expression level of SmeDEF is related with the antibiotic resistance of S.maltophilia.The possible resistance mechanism includes the variations in the intergenic smeD-smeT and/or smeT codon sequence.
