Abstract:ObjectiveTo explore the genetic marks of continuously isolated Escherichia coli (E.coli) and Pseudomonas aeruginosa (P. aeruginosa) and the correlation with nosocomial infection (NI). MethodsPolymerase chain reaction (PCR) was used to detect plasmid AmpC genes (ACT1 and DHA), class Ⅰ integrase gene (IntⅠ1) and disinfectantresistant gene (qacE△1sul1) of E.coli; Four kinds of genetic marks of integron and transposon (qacE△1sul1, merA, tnpA, tnpU) in P. aeruginosa were also detected by PCR. ResultsAmong E.coli, the positive rate of plasmid AmpC genes of ACT1 and DHA was 57.50% and 40.00% respectively, the positive rate of IntⅠ1 and qacE△1 sul1 was 47.50% and 57.50% respectively. Among P. aeruginosa, the positive rate of qacE△1sul1 and merA was 48.57% and 11.43% respectively. There were neither gene tnpA nor gene tnpU in P. aeruginosa strains. ConclusionE.coli isolated from the clinic carries plasmid AmpC genes, IntⅠ1 genes and qacE△1sul1; P.aeruginosa carries qacE△1sul1 and merA. Resistant genes among different bacteria strains can be transmitted, which is significant in epidemiology.