Acinetobacter baumannii isolated from hospital ‐acquired infection: biofilm production and drug susceptibility

In this study, we evaluate relation between these two factors. The biofilm formation was investigated in M63 medium with casein in microtiter plates, and the drug susceptibility was performed by disk diffusion methods. We found that 80–98% strains formed a biofilm. Strains showing sensitivity to amikacin and tobramycin from ICU produced more biofilm than strains showing resistance to these antibiotics. Ceftazidime‐sensitive strains formed a smaller biofilm than resistant. The logistic regression shows association between drug resistance and strains originating from ICU. In case of ceftazidime, strong biofilm formation and descending from ICU reduced the likelihood of drug sensitivity. For other drugs such as aminoglycosides, fluoroquinolones, trimethoprim/sulfamethoxazole, and tetracycline, we found opposite relation (but it was not statistically significance). However, generally it seems that strong biofilm producers from ICUs are often more susceptible to antibiotics. This situation can be explained by the fact that bacteria protected in biofilm do not need mechanisms responsible for resistance of planktonic cells.
Source: APMIS - Category: Research Authors: Tags: Original Article Source Type: research