Table 4.

Comparison of results obtained from crystal violet staining of biofilms in literature.

Method	Duration	Temp.	Substrate	Strains	Summary	Reference
MPA stained with crystal violet	24 h	37 °C and 10 °C	Bacterial biomass	19 persistent, 20 prevalent, 19 rare (27 genotypes)	Persistence/prevalence did not correspond to a higher biofilm formation, supplementation with NaCl in nutrient deprived cells improved biofilms, production ~5 times greater at 37 °C than at 10 °C	[159]
MPA/stainless steel sheets stained with crystal violet	24 h	37 °C	Bacterial biomass	ST1, ST2, ST5, ST8, ST9, ST87, ST121, ST199, ST321, ST388	All strains formed moderate biofilms on microtiter plates but not on stainless steel	[158]
MPA stained with crystal violet	16, 24 and 36 h	30 °C	Bacterial biomass	Range of serotypes from food/clinical samples	Lineage I isolates produced more biofilm, no significant difference in biofilm formation found between food/clinical isolates	[163]
MPA stained with crystal violet	224 h	37 °C	Bacterial biomass	Range of serotypes	Lineage II (persistent) isolates produced more biofilms, biofilm formation correlated with phylogenetic division but not serotype	[164]
MPA stained with crystal violet	24 h (37C) and 5 days (4C)	37 °C and 4 °C	Bacterial biomass	Range of serotypes from food/clinical samples	Higher biofilm formation at 37 °C with food isolates producing slightly more biofilm at both temperatures	[165]