In order to survey antibiotic resistance of clinical isolates carbapenem-resistant A cinetobacter baumannii in Meizhou and to investigate resistance mechanism and molecular epidemiological characteristics ,a total of 210 non-duplicated clinical isolates of carbapenem-resistant Acinetobacter baumannii from January 2012 to December 2012 were collected .The K-B disk diffusion method was applied for the drug-susceptibility test ,a modified Hodge test was used for the screening of carbapen-emase ,PCR was used to amplify carbapenemase genes (including IMP ,VIM ,OXA-23 ,OXA-24 ,OXA-51 and OXA-58) ,and the positive products were sequenced .Enterobacterial repetitive intergenic consensus PCR (ERIC-PCR) was used for DNA typing and test of homology .Our results on the percentage of strains resistant for antibiotics tested were higher than 60% except for polymyxin B was 0 .48% .There were 163 positive strains by the modified Hodge test ,accounting for 77 .62% .OXA-51 gene was identified in 198 strains (94 .29% ) ,OXA-23 in 165 strains (78 .57% ) ,and VIM in 9 strains (4 .29% ) ,OXA-24 ,OXA-58 and IMP gene was not identified by PCR amplification .Seven genomic types were included in the 210 carbapenem-resistant Acinetobacter baumannii .The major prevalence types were Type A (97 strains) ,Type B (44 strains) and Type H (25 strains) . In conclusion ,multiple drug resistance of clinically isolated carbapenem-resistant A cinetobacter baumannii is a serious problem in Meizhou .Production of OXA-51 ,OXA-23 and IMP carbapenemases is an important mechanism of resistance to carbapenem antibiotics ,and there is prevalence of the same clones in these carbapenem-resistant strains .

Objective To analyze the detection rate and drug resistance tendency of Acinetobacter (A .) baumannii in Meizhou area during 2008-2012 in order to provide the guidance for clinicians′medication .Methods The detection rate and drug resistant rate of A .baumanii in the clinical specimens submitted from 5 hospitals in Meizhou during 2008 -2012 were retrospectively ana-lyzed .The antimicrobial susceptibility test was performed by the disk diffusion method .The WHONET 5 .4 and SPSS18 .0 soft-wares were adopted to analyze the data .Results The detection rates of A .baumanii in these five years were 12 .91% ,15 .40% , 11 .94% ,13 .59% and 14 .00% respectively .In the sources of strains ,sputum had the highest distribution rate of 68 .99% (1 713/2 483) ,in the distribution of departments ,ICU had the highest distribution rate of 33 .91% (842/2 483) .The resistance rate of A . baumannii to cefoperazone/shubatam ,meropenem and imipenem were below 30% in the five years ,but showed the upward tenden-cy .The 5-year total drug resistance rates of A .baumanii to 18 kinds of antibacterial drugs were statistically different between ICU and non-ICU department (P<0 .05) ,the drug resistant rate of isolates from ICU was higher than that from the non-ICU depart-ments .The isolation rate of multi-drug resistant strains of A .baumanii was fluctuated in about 50% during these five years except the lower isolation rate in 2008 ,the isolation rate of pan-drug resistant A .baumanii and carbapenem resistance A .baumanii showed the upward tendency .Conclusion The drug resistance rate of A .baumanii is gradually increased .The drug resistance monitoring of A .baumanii in ICU should be strengthened .Antimicrobial agents should be reasonably used for maximizing to retard the emergence of drug resistant strains .

The regulator of expression of virion(Rev)protein binds specifically to the Rev-responsive element(RRE)RNA in order to regulate the expression of the human immunodeficiency virus(HIV)-1 genes.Fluores-cence indicator displacement assays have been used to identify ligands that can inhibit the Rev-RRE interaction;however,the small fluorescence indicators cannot fully replace the Rev peptide or protein.As a result,a single rhodamine B labeled Rev(RB-Rev)model peptide was utilized in this study to develop a direct and efficient Rev-RRE inhibitor screening model.Due to photon-induced electron transfer quenching of the tryptophan residue on the RB fluorophore,the fluorescence of RB in Rev was weakened and could be dramatically reactivated by interaction with RRE RNA in ammonium acetate buffer(approximately six times).The interaction could reduce the electron transfer between tryptophan and RB,and RRE could also increase RB fluorescence.The inhibitor screening model was evaluated using three known positive Rev-RRE inhibitors,namely,proflavin,6-chloro-9-[3-(2-chloroethylamino)pro-pylamino]-2-methoxyacridine(ICR 191),and neomycin,as well as a negative drug,arginine.With the addition of the positive drugs,the fluorescence of the Rev-RRE decreased,indicating the displacement of RB-Rev.This was confirmed using atomic force microscopy(AFM)and the fluorescence was essentially unaffected by the addition of arginine.The results demonstrated that RB-Rev can be used as a fluorescent probe for recognizing small ligands that target RRE RNA.The Rev-RRE inhibitor screening model offers a novel approach to evaluating and identifying long-acting Rev inhibitors.