Vibrio parahaemolyticus and Vibrio vulnificus in vitro colonization on plastics influenced by temperature and strain variability

Abstract

Marine bacteria often exist in biofilms as communities attached to surfaces, like plastic. Growing concerns exist regarding marine plastics acting as potential vectors of pathogenic Vibrio, especially in a changing climate. It has been generalized that Vibrio vulnificus and Vibrio parahaemolyticus often attach to plastic surfaces. Different strains of these Vibrios exist having different growth and biofilm-forming properties. This study evaluated how temperature and strain variability affect V. parahaemolyticus and V. vulnificus biofilm formation and characteristics on glass (GL), low-density polyethylene (LDPE), polypropylene (PP), and polystyrene (PS). All strains of both species attached to GL and all plastics at 25, 30, and 35°C. As a species, V. vulnificus produced more biofilm on PS (p ≤ 0.05) compared to GL, and biofilm biomass was enhanced at 25°C compared to 30° (p ≤ 0.01) and 35°C (p ≤ 0.01). However, all individual strains’ biofilm biomass and cell densities varied greatly at all temperatures tested. Comparisons of biofilm-forming strains for each species revealed a positive correlation (r = 0.58) between their dry biomass weight and OD570 values from crystal violet staining, and total dry biofilm biomass for both species was greater (p ≤ 0.01) on plastics compared to GL. It was also found that extracellular polymeric substance (EPS) chemical characteristics were similar on all plastics of both species, with extracellular proteins mainly contributing to the composition of EPS. All strains were hydrophobic at 25, 30, and 35°C, further illustrating both species’ affinity for potential attachment to plastics. Taken together, this study suggests that different strains of V. parahaemolyticus and V. vulnificus can rapidly form biofilms with high cell densities on different plastic types in vitro. However, the biofilm process is highly variable and is species-, strain-specific, and dependent on plastic type, especially under different temperatures.

Sources and contamination routes of seafood with human pathogenic Vibrio spp.: A Farm‐to‐Fork approach

“…Due to multiple experimental conditions, it is difficult to reach a consensus on the effect of temperature on the formation of V. parahaemolyticus biofilms. Castro-Rosas and Escartin (2002) and Han et al (2016) agreed that the formation of V. parahaemolyticus biofilms on abiotic (stainless steel) and biotic surfaces (crustaceans and shrimp) is favored by temperatures above 30 • C. However, Leighton et al (2022) showed a greater biomass of V. parahaemolyticus biofilms cultured on glass and plastic at 25 • C compared to those cultured at 30 and 35 • C. Using the crystal violet microplate assay, Song et al (2017) also noted greater biofilm formation at 25 • C relative to 15 or 37 • C for a collection of both pathogenic and nonpathogenic V. parahaemolyticus strains. They also reported that, as a group, the pathogenic strains produced more biofilm at all temperatures.…”

“…However, Leighton et al. (2022) showed a greater biomass of V. parahaemolyticus biofilms cultured on glass and plastic at 25°C compared to those cultured at 30 and 35°C. Using the crystal violet microplate assay, Song et al.…”

“…are able to form biofilms on biotic surfaces such as crustacean shells, fish opercula, or mollusk shells (Wang et al., 2022; Yu & Rhee, 2023), and this may enhance their survival through the processing chain and represent a significant risk of cross‐contamination, especially during the processing of seafood products. In addition, numerous studies have shown that these pathogens are capable of adhering to and/or forming biofilms on several types of materials commonly found in food processing plants, such as plastic or glass (Drescher et al., 2016; Gallego‐Hernandez et al., 2020; Leighton et al., 2022; Rosa et al., 2018). In the food industry, the most widely used material for the fabrication of processing equipment, pipelines, and work surfaces is stainless steel.…”

“…Mougin et al (2019) did not observe any difference in biofilm production of V. parahaemolyticus on stainless steel between 8 and 37 • C in three different media, but highlighted that V. cholerae exhibited greater survival at 8 • C rather than 37 • C, when cultivated in brine. Regarding V. vulnificus, it has been demonstrated that biofilm production by V. vulnificus cultured on glass and plastic is more significant at low temperatures (24-25 • C) than at high temperatures (35 and 37 • C) (Çam & Brinkmeyer, 2020;Leighton et al, 2022;Velez et al, 2023). In contrast, in their study of biofilms formed in glass tubes, Hernández-Cabanyero et al (2020) showed no significant difference in biofilm production at temperatures ranging from 20 to 37 • C, although a slight increase in biofilm quantity with increasing temperature was observed.…”

Vibrio parahaemolyticus and Vibrio vulnificus in vitro biofilm dispersal from microplastics influenced by simulated human environment

“…Biofilm formation experiments on MPs were adapted from O'Toole (2011) , Hamanaka et al (2012) , Valquier-Flynn et al (2017) , and Leighton et al (2023) . In summary, MPs were generated from slide coupons of low-density polyethylene (LDPE), polypropylene (PP), and polystyrene (PS) ( Table 3 , Biosurface Technologies, Boseman, MT, United States) by cutting the coupons to dimensions of 4 mm x 1 mm.…”