ABSTRACT
Objective To analyze the distribution of common drug-resistance genotypes of multi-drug resistant bacteria (MDRB) in second class and below hospitals in 3 big areas of Chongqing City for perfecting the bacterial drug resistance surveillance network in local area.Methods In 7206 detected strains of MDRB, the re-cultured pure colonies of top five bacteria in the bacterial strains numer were taken and performed the common drug resistant genotyping detection and comparative analysis by PCR technique and sequencing.Results Acinetobacter spp.was dominated by the genotypes carrying TEM,SUL and GyrA genes,Klebsiella pneumoniae was dominated by the genotypes carrying SHV,GyrA genes,Escherichia coli was dominated by the genotypes carrying TEM,CTX-M,SUL,GyrA,aac (3) Ⅱ genes,Pseudomonas aeruginosa was dominated by genotypes carrying SUL,GyrA genes,Staphylococcus was dominated by genotypes carrying GyrA,aac (6 ′)-aph ′′ genes;among the five strains of MDRB,the majority were the strains with multiple expression of two kinds or four kinds of common drug-resistance genes,in which the detection rate of Escherichia coli multiple expression was highest,reaching 92.74%,the detection rate of Staphylococcus multiple expression was lower.The detection rates of common drug resistant genotypes carried by MDRB had statistical difference among various areas and various years (P<0.05);in the comparison with the gene sequences of corresponding bacteria in NCBI Blastn database,the sequencing results of 7 common drug resistant genotypes carried by 5 kinds of MDRB were basically consistent.Conclusion The common drug-resistant genotypes carried by MDRB detected in the second class and below hospitals of Chongqing City and their distribution are basically consistent with the monitoring levels in the local tertiary hospitals and whole nation.Therefore the antibacterial surveillance of infection pathogenic bacteria should be strengthened in these hospitals,and medication should be rationally used so as to delay the development of pathogenic bacterial drug resistance in local area.
ABSTRACT
Objective To provide an effective basis for clinical control methods of multi-drug-resistant bacterial (MDRB) infections by analyzing the distribution and antimicrobial resistance of MDRB.Methods The French Merieux ATB Expression Automated Analysis System was used for bacterial identification,whereas a drug susceptibility testing was performed by K-B methods.Drug-resistance rate was calculated,and the predisposing factors were analyzed.Results Altogether 811(8.1％) strains were isolated from 9 954 specimens,and the majority of multiply antimircobial-resistant bacteria were Escherichia coli,Coagulase-negative staphylococci,Klebsiella Pneumoniae Staphylococcus aureus,Acinetobacter Baumannii,Pseudommonas aeruginosa,whereas the last two appeared pan resistant strains.Specimen source was mainly from respiratory specimens,accounted for 47.8％,and was mainly distributed in the ICU unit,atout41.8％ ;MDRB enterobacter was highly sensitive to Carbapenems with resistance rates less than 1.5％ and to Amikacin and other inhibitor drugs that rate was less than 30.0％.The resistance rates of MDRB nonfermentative bacteria was ＞ 77.0％ to Carbapenem antibacterial drugs whereas to non-resistance was found to polymyxin and only 20.0％ resistance rate to Cefoperazone/sulbactam.MDRB staphylococcus was 100.0％ sensitive to Vancomyci,Teicoplanin and Linezolid and less sensitive (＜ 30.0％) to chloramphenicol and rifampicin.MDRB showed high resistance rate to other antibacterial drugs.The predisposing factors included age,other disease,hospitalization over two weeks,the usage of multiply antimicrobial especially cephalosporins overtoppinh 7 days,and invasive operations.Conclusion The major MDRBs are resistant to common-used antimicrobial drugs.It is nesessary to pay attention to the differences.