Carbapenemase genes and homology of Acinetobacter baumannii in two hospitals of Qingdao / 中国感染控制杂志

ABSTRACT

Objective To investigate antimicrobial resistance,distribution,and carriage of carbapenemase genes of Acinetobacterbaumannii(AB)from two hospitals in Qingdao.Methods 145 AB isolates collected from two hospi-tals (78 from hospital A,67 from hospital B)were performed antimicrobial susceptibility testing,carbapenemase genes were amplified by polymerase chain reaction (PCR);homology analysis were conducted with enterobacterial repetitive intergenic consensus (ERIC)-PCR.Results AB from hospital A were generally resistant to 16 commonly used antimicrobial agents,with the lowest resistant rate of 3.85% to cefoperazone/sulbactam,followed by resist-ance rate of 16.67% to minocycline,resistant rates to the other antimicrobial agents were all>73% . AB from hos-pital B were generally resistant to 23 commonly used antimicrobial agents,but the resistance rates to minocycline and tigecycline were both 0,resistance rates to amikacin and levofloxacin were 23.88% and 38.81% respectively, resistant rates to the other antimicrobial agents were all >64% . All strains carried OXA-5 1 gene,the carriage rates of OXA-23 gene in carbapenem-resistant group were 86.76% (59/68)and 56.67% (34/60)in hospital A and B re-spectively,the difference was significant(χ2= 14.53,P<0.001);OXA-58 gene was detected in 3 isolates in hospi-tal A but not detected from hospital B. 145 AB strains were classified into 8 types,the major prevalence types were type A (n= 71)and E(n= 37);the major prevalence types in hospital A were type A (46.15% )and E(41.03% ), hospital B were type A (52.24% )and C (17.91% ).Conclusion Antimicrobial resistance of clinically isolated AB is serious and prevailed in two hospitals. OXA-23 and OXA-51 genes play an important role in AB resistance to car-bapenems.