Purpose: The purpose of this study was to evaluate the sanitary conditions of Florida cantaloupe packinghouses prior to FDA inspections.
Methods: In May 2013, five Florida cantaloupe packinghouses were visited in advance of FDA. Up to 60 swabs per facility were collected from food contact and non-contact surfaces, and water. Each sample was enumerated for total plate counts (TPC), generic E. coli, and coliforms, and enriched for Listeria spp. and L. monocytogenes by standard methods. Presumptive L. monocytogenes colonies were confirmed by amplification of the sigB gene by PCR and analyzed by PFGE.
Results: Environmental samples (270 swabs and 1 water sample; 172 ‘zone 1’ food contact swabs) were collected. Average zone 1 TPC for all facilities was 6.9 ± 0.9 log CFU/swab; within facilities zone 1 TPC’s ranged from 5.4 ± 1.5 (facility D) to 7.5 ± 8.3 (facility D) log CFU/swab. Coliforms and Listeria spp. were recovered from 36.6% and 73.2% of zone 1 swabs from all facilities samples, ranging between 27.8% (facility A) - 47.1% (facility D) and 50.0% (facility D) - 86.5.4% (facility A), respectively. E. coli was not recovered from any facility (limit of detection 50 CFU/swab). Listeria monocytogenes was recovered from 2/270 swabs (0.7%) in one facility; both food contact surfaces. PFGE patterns of the two isolates were identical. Following additional facility sanitation, L. monocytogenes was not detected upon retesting.
Significance: The prevalence of L. monocytogenes in Florida cantaloupe packinghouses was low; FDA sampling did not find any positive samples. TPC, coliforms, E. coli and Listeria spp. were not good indicators of L. monocytogenes.