Enviro-mapping baseline of microbial indicators in a beef fabrication floor as a tool for sanitary design, sanitizing interventions, and pathogen monitoring

Environmental mapping of microbial indicators can provide data evidence for processors to make decisions focused on preventing cross-contamination. The purpose of this in-plant study was to identify microbial harborage sites and concentration throughout the day in the fabrication area of a beef processing facility. The lines studied were Chuck (L1), Loin (L2), Round (L2), and Trim (L4). The sampling was performed in 3 repetitions divided into five time points: pre-operation, morning, before cleaning, after cleaning, and at the end of the shift. Microtally™ cloths were used to sample cutting boards, conveyor belts, drains, stairs, and handrails. MicroSnap™ swabs were used to sample knives, and board frames. Aerobic plate counts (APC), Enterobacteriaceae (EB), and Escherichia coli (EC) counts were determined using the TEMPO™ system for Microtally™ and the EnSURE™ Touch system for MicroSnap™ samples. The following results are represented in logCFU/mL. Cutting Boards started below the limit of quantification (<LOQ) in pre-operation, after 3hrs counts increased to 3.41, 2.91 and 2.97 for AC; for EB it went up to 2.62, 2.19 and 2.03 and for EC counts were 0.55, 1.03 and 1.04 for L1, L2 and L3, respectively. Counts were similar before mid-day cleaning and at the end of the shift, however, there was a reduction in L1 after midday cleaning of 0.87 (p<0.05). Conveyor belts AC, EB and EC counts were low in pre-operation. After 3hrs, AC counts increased to 3.52, 3.49, 3.36 and 3.69: EB were 2.93, 2.46, 2.42 and 2.92; for EC 1.26, 1.06, 0.93 and 1.33 for L1, L2, L3 and L4, respectively. Results remained similar throughout the day. Board frames pre-operation were <LOQ for EB and EC in the 3 lines, AC started in 1.05, 0.76 and <LOQ in L1, L2 and L3, respectively. After 3hrs, counts went up to 2.9, 3.75 and 3.86 for AC; for EB counts increased to 2.65, 2.37 and 2.08; for EC counts increased to 0.53, 0.78 for L1 and L2, respectively. No increase or reduction was found for the rest of the day in L1 and L2, L3 reduced after midday cleaning of 0.47 for EB and 0.84 for EC (p<0.05). Drains were already high pre-operation and there was no significant increase or decrease for the rest of the day in all lines. Knives loads pre-operation were 0.95, 2.06 and 0.77 for AC; 0.57, 0.87 and 0.76 for EB; for EC counts were <LOQ in L1, L2 and L3, respectively. After 3hrs, there was no significant increase in any indicator for the 3 lines. Finally for handrails and stairs there was no significant reduction or increase from pre-operation to the end of the day. Results can be used as a microbiological baseline for assessing the hygienic conditions during operations in a beef fabrication room. The cleaning and sanitation protocol performed pre-operation is effective to remove the buildup of the day. However, by the first 3 hours of operation, microbial contamination can reach high levels of contamination that are maintained throughout the day, meaning that the limited cleaning performed at lunch break is not effective to reduce contamination on surfaces.