1.Resistance mechanism and molecular epidemiological characteristics of isolated clinically carbapenem-resistant Acinetobacter baumannii in Meizhou, China
Guangwen XIAO ; Xuetao WANG ; Yafeng QIAO ; Shangping ZOU ; Zhendong YE
Chinese Journal of Zoonoses 2014;(8):816-820
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 .
2.Analysis of drug resistance tendency of Acinetobacter baumannii in Meizhou area during 2008-2012
Guangwen XIAO ; Xuetao WANG ; Yafeng QIAO ; Shangping ZOU ; Zhendong YE
International Journal of Laboratory Medicine 2014;(15):2053-2055
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 .