Comparison of plate counting with flow cytometry, using four different fluorescent dye techniques, for the enumeration of Bacillus cereus in milk.

This study aimed to compare the performance of flow cytometry methods with plate counting for the enumeration of bacteria, using Bacillus cereus as a model organism. It was found that the cFDA-propidium iodide, CellROX™ Green-propidium iodide, and DiOC dye techniques had similar accuracy to plate counting, while the SYTO 24-propidium iodide dye technique was not as accurate. The four dye techniques had comparable precision to plate counting, with the CellROX™ Green-propidium iodide dye having the greatest precision.

Changes in Sodium, Calcium, and Magnesium Ion Concentrations That Inhibit Geobacillus Biofilms Have No Effect on Anoxybacillus flavithermus Biofilms.

This study investigated the effects of varied sodium, calcium, and magnesium concentrations in specialty milk formulations on biofilm formation by Geobacillus spp. and Anoxybacillus flavithermus. The numbers of attached viable cells (log CFU per square centimeter) after 6 to 18 h of biofilm formation by three dairy-derived strains of Geobacillus and three dairy-derived strains of A.

Preconditioning with cations increases the attachment of Anoxybacillus flavithermus and Geobacillus species to stainless steel.

Preconditioning of Anoxybacillus flavithermus E16 and Geobacillus sp. strain F75 with cations prior to attachment often significantly increased (P ≤ 0.05) the number of viable cells that attached to stainless steel (by up to 1.

Influence of cations on growth of thermophilic Geobacillus spp. and Anoxybacillus flavithermus in planktonic culture.

Free ions of Na(+), K(+), Ca(2+), and Mg(2+) influenced the optical density of planktonic cultures of thermophilic bacilli. Anoxybacillus flavithermus E16 and Geobacillus sp. strain F75 (milk powder manufacturing plant isolates) and A.

Recovery of Cronobacter sakazakii from environmental surface swabbing materials using a 5-h enrichment procedure.

This study aimed to reduce the time taken to detect low numbers of Cronobacter sakazakii inoculated onto environmental swabs (100, 10 or 1 cfu per swab) using a simple plating procedure for application in a dairy testing laboratory. Three types of environmental swabs (Biolab FlexiSwab, gauze swabs and the Whatman SwabCheck Polywipe sponge) were inoculated with either Cron. sakazakii in single culture or Cron.