Scientific Publications by FDA Staff
J Appl Microbiol 2011 Oct;111(4):904-14
Preparation of reference strains for validation and comparison of mycoplasma testing methods.
Dabrazhynetskaya A, Volokhov DV, Ikonomi P, Brewer A, Chang A, Chizhikov V
Aims: To optimize growth conditions for preparation of stocks of mycoplasma reference strains to obtain highly viable and disperse samples with low ratios of genomic copy (GC) number to that of colony forming units (CFU). These stocks are required for assessment of relative Limits of Detection (LOD) of alternative nucleic acid testing (NAT)-based methods in comparison to the conventional microbiological methods. Methods and Results: A kinetics study was used to assess the changes in ratios between the numbers of GC and CFU at different growth phases of six different mycoplasma cultures Acholeplasma laidlawii, Mycoplasma gallisepticum, Mycoplasma arginini, Mycoplasma fermentans, Mycoplasma orale and Mycoplasma pneumoniae. All tested mycoplasmas demonstrated low GC/CFU ratios (= 10) within the log and early stationary growth phases. A significant increase of GC/CFU ratios was observed at the very late stationary and death phases, when the titer of cultures has declined. Similar patterns of GC/CFU profiles were observed for A. laidlawii and Myc. gallisepticum co-cultured with suspension of Chinese hamster ovary (CHO) cells. Conclusions: Tested mycoplasma strains harvested at the exponential - early stationary phases of growth demonstrated the lowest GC/CFU ratios and low propensity to form filamentous structures or aggregates under proposed conditions and can be used for preparation of a mycoplasma reference panel for methods comparability study.
|Category: Journal Article|
|PubMed ID: #21794032||DOI: 10.1111/j.1365-2672.2011.05108.x|
|Includes FDA Authors from Scientific Area(s): Biologics|
|Entry Created: 2011-10-03||Entry Last Modified: 2012-08-29|