Influence of storage on monodispersed cells of Mycobacterium terrae used for quantitative carrier test prEN 14563.
The degree of cell clumping increased with time of storage (1% cell clumps immediately after homogenization and 3 and 6.5% after 48 and 96 h of storage, respectively), and the number of living single cells decreased. Quantitative carrier tests were carried out with these cells using ortho-phthaldialdehyde (OPA) and coco fatty aminoxethylate as biocides. In contrast to OPA, with coco fatty aminoxethylate the reductions obtained with freshly homogenized mycobacteria were significantly higher (P = 0.02) than those obtained with mycobacteria kept in the refrigerator for 4 days. Therefore, it is advisable to prepare the test suspension freshly for each test.
Woelk
Eva
E
Institute of Botany, Department of Microbiology, University of Hamburg, D-22602 Hamburg, Germany.
Goroncy-Bermes
Peter
P
Sand
Wolfgang
W
D015169:Colony Count, Microbial; D004202:Disinfectants / Q000494:pharmacology*; D004866:Equipment Contamination; D005060:Europe; D008826:Microbial Sensitivity Tests / Q000592:standards; D009170:Nontuberculous Mycobacteria / Q000166:cytology / Q000187:drug effects; D013048:Specimen Handling / Q000379:methods*; D009764:o-Phthalaldehyde / Q000494:pharmacology*
D004202:Disinfectants; D009764:o-Phthalaldehyde