Cutting boards as a source of high histamine-producing bacteria: Persistence and transfer to fish fillets

Microbial contamination of food contact surfaces, particularly cutting boards, poses a significant risk for secondary contamination and foodborne illness, with histamine-producing bacteria (HPB) being a key concern due to their association with scombroid poisoning. This study examined the prevalence, biofilm formation, persistence, and cross-contamination potential of high histamine-producing (HHP) bacteria isolated from cutting boards in fish retail markets. Out of 288 isolates, two Gram-negative strains— Morganella morganii and Raoultella planticola —were identified as high histamine producers. Both strains demonstrated biofilm-forming ability under different nutrient conditions (TSB, diluted TSB, distilled water) and temperatures (22°C and 35°C). Persistence assays revealed that surface-associated M. morganii cells declined to undetectable levels by day 8, whereas R. planticola remained viable until day 14. Biofilm cells exhibited prolonged survival, with R. planticola persisting for 20 days under dry, nutrient-deprived conditions. Bacterial transfer was found to occur at varying contamination levels (4–6 log CFU/cm 2 ) and contact times (2–10 minutes). Bacterial transfer was found to increase significantly with higher initial contamination levels (P < 0.05). However, no significant variation in transfer efficiency was observed across different contamination levels or contact times (P > 0.05). Furthermore, transfer rates were observed to decrease progressively with consecutive fillet contacts, regardless of the initial inoculum level or contact duration. The demonstrated potential for cross-contamination to fish fillets, even after sequential contacts, underscores a substantial risk for scombroid poisoning and highlights the need for stringent hygiene protocols targeting biofilm removal in fish retail markets. > Histamine-producing bacteria were isolated from cutting board surfaces. > M. morganii and R. planticola were identified as high histamine producers. > R. planticola was a superior biofilm former to M. morganii , especially at 22°C. > Bacterial transfer rose with contamination but efficiency stayed the same. > Transfer rates decreased with each consecutive fillet contact.