title: Comparison of swab transport media for recovery of Listeria monocytogenes from environmental samples.
abstract: Environmental monitoring is recognized as an important strategy for controlling Listeria monocytogenes in food processing facilities. Samples are taken by swabbing environmental surfaces, and the swabs are immersed in a medium for transport to the laboratory. In this study, buffered  peptone water (BPW), Dey-Engley neutralizing broth (DE), neutralizing buffer (NB), Letheen broth (LE), and newly described MCC buffer (MCC) were evaluated as transport media for recovery of sanitizer-stressed L. monocytogenes from inoculated swabs. After storage at 4°C, the media  performed similarly, but at 25°C relative recovery efficiency from the inoculated sponges was DE > LE > BPW > MCC > NB. Recoveries from stainless steel surfaces followed similar trends. MCC, DE, and NB were compared for L. monocytogenes recovery in the presence of Escherichia  coli, Enterococcus faecalis, Lactobacillus plantarum, Pseudomonas fluorescens, and Listeria innocua. After 4°C storage, all population levels changed little; after 25°C storage, DE allowed the best growth of L. monocytogenes regardless of other species present. MCC,  DE, and NB performed similarly for recovery of L. monocytogenes from an artificial milk biofilm and for recovery of Listeria spp. from swabs obtained from a meat processing facility. Transport medium formulation, time and temperature of swab storage, and coexistence of other  species affect recovery of sanitizer-stressed L. monocytogenes from environmental swabs. The study confirms the need to maintain 4°C storage conditions during swab transport.
authors.affiliation: National Center for Food Safety and Technology, Illinois Institute of Technology, 6502 South Archer Road, Bedford Park, Illinois 60501, USA.
authors.forename: L
authors.initials: L
authors.lastname: Zhu
authors.forename: D
authors.initials: D
authors.lastname: Stewart
authors.forename: K
authors.initials: K
authors.lastname: Reineke
authors.forename: S
authors.initials: S
authors.lastname: Ravishankar
authors.forename: S
authors.initials: S
authors.lastname: Palumbo
authors.forename: M
authors.initials: M
authors.lastname: Cirigliano
authors.forename: M
authors.initials: M
authors.lastname: Tortorello
mesh_terms: D015169:Colony Count, Microbial; D004783:Environmental Microbiology; D004866:Equipment Contamination; D005506:Food Contamination / Q000517:prevention & control*; D005516:Food Microbiology; D005525:Food-Processing Industry / Q000592:standards*; D008089:Listeria monocytogenes / Q000302:isolation & purification*; D013193:Stainless Steel; D013696:Temperature
chemical_list: D013193:Stainless Steel