Evaluation of automated time-lapse microscopy for assessment of in vitro activity of antibiotics.
This study aimed to evaluate the potential of a new time-lapse microscopy based method (oCelloScope) to efficiently assess the in vitro antibacterial effects of antibiotics. Two E. coli and one P. aeruginosa strain were exposed to ciprofloxacin, colistin, ertapenem and meropenem in 24-h experiments. Background corrected absorption (BCA) derived from the oCelloScope was used to detect bacterial growth. The data obtained with the oCelloScope were compared with those of the automated Bioscreen C method and standard time-kill experiments and a good agreement in results was observed during 6-24h of experiments. Viable counts obtained at 1, 4, 6 and 24h during oCelloScope and Bioscreen C experiments were well correlated with the corresponding BCA and optical density (OD) data. Initial antibacterial effects during the first 6h of experiments were difficult to detect with the automated methods due to their high detection limits (approximately 105CFU/mL for oCelloScope and 107CFU/mL for Bioscreen C), the inability to distinguish between live and dead bacteria and early morphological changes of bacteria during exposure to ciprofloxacin, ertapenem and meropenem. Regrowth was more frequently detected in time-kill experiments, possibly related to the larger working volume with an increased risk of pre-existing or emerging resistance. In comparison with Bioscreen C, the oCelloScope provided additional information on bacterial growth dynamics in the range of 105to 107CFU/mL and morphological features. In conclusion, the oCelloScope would be suitable for detection of in vitro effects of antibiotics, especially when a large number of regimens need to be tested.
Department of Medical Sciences, Section of Infectious Diseases, Uppsala University, Uppsala, Sweden; Department of Pharmaceutical Biosciences, Uppsala University, Uppsala, Sweden.
Wanchana
W
Ungphakorn
Department of Medical Sciences, Section of Infectious Diseases, Uppsala University, Uppsala, Sweden.
Christer
C
Malmberg
Department of Medical Sciences, Section of Infectious Diseases, Uppsala University, Uppsala, Sweden.
Pernilla
P
Lagerbäck
Department of Medical Sciences, Section of Infectious Diseases, Uppsala University, Uppsala, Sweden.
Otto
O
Cars
Department of Pharmaceutical Biosciences, Uppsala University, Uppsala, Sweden.
Elisabet I
EI
Nielsen
Department of Medical Sciences, Section of Infectious Diseases, Uppsala University, Uppsala, Sweden. Electronic address: thomas.tangden@medsci.uu.se.
Thomas
T
Tängdén
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002939:Ciprofloxacin / Q000494:pharmacology; D003091:Colistin / Q000494:pharmacology; D015169:Colony Count, Microbial; D024901:Drug Resistance, Multiple, Bacterial; D000077727:Ertapenem; D004926:Escherichia coli / Q000187:drug effects* / Q000254:growth & development; D000077731:Meropenem; D008826:Microbial Sensitivity Tests; D050296:Microbial Viability / Q000187:drug effects; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000254:growth & development; D013845:Thienamycins / Q000494:pharmacology; D059008:Time-Lapse Imaging / Q000295:instrumentation / Q000379:methods*; D047090:beta-Lactams / Q000494:pharmacology
D000900:Anti-Bacterial Agents; D013845:Thienamycins; D047090:beta-Lactams; D002939:Ciprofloxacin; D000077731:Meropenem; D000077727:Ertapenem; D003091:Colistin
Bacterial morphology; Bioscreen C; Gram-negative bacteria; PKPD; Time-kill experiments; oCelloScope