The Detection of AmpC enzyme and extended-spectrumβ-lactamase and analysis of drug resistance in Pseudomonas aeruginosa

Objective To investigate the prevalence of AmpC βlactamases and extended-spectrumβ-lactamases in Pseudomonas aeruginosa srain and its impact on antibiotic susceptibility.Methods The susceptibility study was tested using the disc diffusion method according to recommendation of the Clinical and Laboratory Standards Institute.A modified three-dimensional extract method was used to determine the phenotype of Pseudomonas aeruginosa harboring AmpC β-lactamases and extended-spectrumβ-lactamases.Results Among 106 strains of Pseudomonas aeruginosa,17.4% produced only AmpC β-lactamases 8.7% produced only ESBLs 10.7% produced both highlevel AmpC β-lactamases and ESBLs.Lactamase producing strains were only susceptible to meropenem,imipenem.non-lactamase producing strains were susceptible to most antibiotics.Conclusion The incidence of lactamases in Pseudomonas aeruginosa was rather high,lactamase producing strains show more resistance to most antibiotics than non-lactamase producing strains.