Abstract

In this work, bacteria presented in environmental samples in the processing area of squid sushi (SQ) production plants were isolated and evaluated for their ability to survive or resist various sanitizing agents. A total of 105 environmental swab samples from the food contact surface (FCS) and handling equipment were collected. A high load of bacteria (>2 log CFU/cm²) was observed in 29 samples of three sampling visits. Nylon contact surface was a source of the highest microbial load (44.0 %), followed by polyvinyl chloride (PVC) (26.7 %) and stainless steel (26.0 %). A total of 22 psychrophilic bacteria were isolated from 16 samples (15.2 %), 53 mesophilic bacteria were recovered from 50 samples (47.6 %), and only one isolate of Listeria monocytogenes was also found (0.9 %). From the above, only seven psychrophilic bacteria, 20 mesophilic bacteria, and L. monocytogenes were classified as sanitizer-resistant bacteria (MIC > 201.1 mg/L for cationic, 1,362.9 mg/L for anionic, and 103.6 mg/L for non-ionic sanitizer). Major resistant isolates were classified in the genus of Acinetobacter spp., Bacillus spp., Pseudomonas spp., and Serratia spp. as spoilage bacteria. A few isolates were pathogenic bacteria, including Staphylococcus spp. and L. monocytogenes. These findings suggest that FCS and handling equipment are common transferred points where diverse bacteria can transfer to and contaminate food products. Effective cleaning and sanitizing procedures and the types of sanitizing agents used for cleaning are important to prevent microbial contamination and lower the risks associated with foodborne illness from consuming contaminated foods.