iofilm formation and resistance to sanitizers by Salmonella spp. Isolated from the peanut supply chai

Author(s)

von Hertwig, Aline M. ^[1] ; Prestes, Flavia S. ^[1] ; Nascimento, Maristela S. ^[1]

Affiliation

^[1] Univ Estadual Campinas, Fac Food Engn, Campinas, SP - Brazil

• Document type: Journal article
• Source: Food Research International; v. 152, FEB 2022.
• Web of Science Citations: 0

Abstract

Pathogens such as Salmonella can be difficult to control in low-moisture food (LMF) processing plants and because of this its presence especially in biofilm mode should be prevented in such an environment. This study evaluated the capacity of Salmonella strains isolated from the peanut supply chain (S. Muenster, S. Miami, S. Glostrup, S. Javiana, S. Oranienburg and S. Yoruba) to form biofilm as well as their resistance to sanitizers (sodium hypochlorite, peracetic acid, quaternary ammonium, alkaline chlorinated solution and biguanide). Regarding biofilm formation, there was no significant difference (p 0.05) between the temperatures was noted in the first hours of incubation. The sessile cells reached counts between 3 and 4 log CFU/cm2 at 25 degrees C whereas 5 log CFU/cm2 was observed at 37 degrees C after 8 h. From 24 h the counts were above 6 log CFU/cm2 for both temperatures. Nevertheless, the SEM images of the 6-strain pool showed the highest density of adhered cells after 48 h at 25 degrees C and 24 h at 37 degrees C on PP, and after 48 h at both temperatures on SS. Peracetic acid (300 mg/L) had the shortest action time against 24-h biofilm on SS and PP, with sessile cell counts below the limit of detection (0.59 log CFU/cm2) after 3 min. For 48-h and 96-h biofilm, sodium hypochlorite (200 mg/L) decreased>4 log CFU/cm2 within 5 min. Quaternary ammonium (350 mg/L) and chlorinated alkaline detergent (200 mg/L) showed intermediate performances. Only biguanide (800 mg/L) did not reduce the biofilm counts to below the limit of detection in any of the conditions evaluated. The results indicated high biofilm formation ability of the Salmonella strains isolated from the peanut supply chain. Nevertheless, in general the biofilms were sensitive to most sanitizers within 15 min of treatment. This was the first study which evaluated biofilm formation by Salmonella isolated from the peanut supply chain. Data obtained here will contribute to optimize the hygiene practices in LMF manufacturing plants. (AU)

• FAPESP's process: 16/18724-3 - Characterization of Salmonella isolated from low water activity products: Virulence profile, resistance to antibiotics, biofilm formation, resistance to hygiene and technological processes
• Grantee: Maristela da Silva Do Nascimento
• Support Opportunities: Regular Research Grants