Scientific research

Automated time-lapse microscopy a novel method for screening of antibiotic combination effects against multidrug-resistant Gram-negative bacteria.

Ungphakorn, W., Lagerbäck, P., Nielsen, E. I., & Tängdén, T. (2017).

Clinical Microbiology and Infection

Antibiotic combinations are often used for carbapenemase-producing Enterobacteriaceae (CPE) but more data are needed on the optimal selection of drugs. This study aimed to evaluate the feasibility of a novel automated method based on time-lapse microscopy (the oCelloScope, Philips BioCell A/S, Allerød, Denmark) to determine in vitro combination effects against CPE and to discuss advantages and limitations of the oCelloScope in relation to standard methods.

Four Klebsiella pneumoniae and two Escherichia coli were exposed to colistin, meropenem, rifampin and tigecycline, alone and in combination. In the oCelloScope experiments, a background corrected absorption (BCA) value of ≤8 at 24 h was used as a primary cut-off indicating inhibition of bacterial growth. A new approach was used to determine synergy, indifference and antagonism based on the number of objects (bacteria) in the images. Static time–kill experiments were performed for comparison.

Clinical microbiology and infection