Imipenem resistance and biofilm production in Acinetobacter

Background

Acinetobacter spp. has emerged as a significant hospital pathogen because it is quickly becoming resistant to commonly used routine drugs and is able to survive on various biotic and abiotic surfaces. The main objective of this study is to isolate various clinical strains of Acinetobacter and to analyze its imipenem resistance pattern and biofilm formation.

Materials and methods

Acinetobacter strains were isolated from various clinical isolates. Resistance to imipenem was determined by both disk diffusion and minimum inhibitory concentration (MIC) methods. Biofilm production as a marker of virulence factor was also determined by microtiter plate method.

Results

65 strains of Acinetobacter isolated from various clinical samples. Resistance to imipenem was determined by performing minimum inhibitory concentration (MIC) which showed 46% resistance, compared with disk diffusion i.e. (32.3%). Among 65 strains, 7 were strong biofilm producers, 18 were moderate biofilm producers, 20 were weak biofilm producers and 20 were non biofilm producers. The association of biofilm production and imipenem resistance was found to be statistically significant.

Conclusion

Strains of Acinetobacter showing multi drug resistance and biofilm production remain as a great threat in hospital environment.