Publikationsdatenbank

Biocide susceptibility testing of bacteria:
development of a broth microdilution method (2020)

Art

Zeitschriftenartikel / wissenschaftlicher Beitrag

Autoren

Schug, Angela R. (WE 7)

Bartel, Alexander (WE 16)

Scholtzek, Anissa D. (WE 7)

Meurer, Marita

Brombach, Julian (WE 7)

Hensel, Vivian

Fanning, Séamus

Schwarz, Stefan (WE 7)

Feßler, Andrea T. (WE 7)

Quelle

Veterinary microbiology : an international journal

Bandzählung: 248

Seiten: Artikel 108791

ISSN: 0378-1135

Sprache

Englisch

Verweise

URL (Volltext): https://www.sciencedirect.com/science/article/pii/S0378113520305873

DOI: 10.1016/j.vetmic.2020.108791

Pubmed: 32827921

Kontakt

Institut für Veterinär-Epidemiologie und Biometrie

Königsweg 67
14163 Berlin
+49 30 838 56034
epi@vetmed.fu-berlin.de

Abstract / Zusammenfassung

Biocide susceptibility testing (BST) of bacteria lacks standardised methods. Based on a recently established broth macrodilution BST method, a broth microdilution method for BST was developed. To establish the respective protocol, four reference strains Staphylococcus aureus ATCC® 6538, Enterococcus hirae ATCC® 10541, Escherichia coli ATCC® 10536 and Pseudomonas aeruginosa ATCC® 15442 were investigated for their minimal inhibitory concentrations (MICs) towards quaternary ammonium compounds (benzalkonium chloride), cationic compounds (chlorhexidine), aldehydes (glutardialdehyde) and alcohols (isopropanol) using tryptic soy broth. All combinations of (i) inoculum preparation according to the German Veterinary Medical Society (DVG) or the Clinical and Laboratory Standards Institute (CLSI) with some modifications, (ii) use of 1^st subculture (SC) and 2^nd SC, (iii) direct colony suspension (DCS) with/without glass beads, and (iv) incubation at 37 °C for 24 h, 48 h, and 72 h were compared using seven independent replications. Overall, the reproducibility was high for all abovementioned strain/biocide/parameter combinations. In total, 86.9 % - 100 % of the results were within ± one dilution step of the mode value. The proposed method for a standardised BST protocol comprises (i) two different inoculum densities, (ii) the use of a fresh overnight culture (1^st SC or 2^nd SC), (iii) the preparation of the inoculum suspension by either of the two methods using DCS with or without glass beads, and (iv) the incubation at 37 °C for 24 h. This broth microdilution method will help to harmonize BST of bacterial pathogens in routine diagnostics.