Modeling pH and Temperature Effects as Climatic Hazards in Vibrio Vulnificus and Vibrio Parahaemolyticus Planktonic Growth and Biofilm Formation

Abstract

Climate‐induced stressors, such as changes in temperature, salinity, and pH, contribute to the emergence of infectious diseases. These changes alter geographical constraint, resulting in increased Vibrio spread, exposure, and infection rates, thus facilitating greater Vibrio ‐human interactions. Multiple efforts have been developed to predict Vibrio exposure and raise awareness of health risks, but most models only use temperature and salinity as prediction factors. This study aimed to better understand the potential effects of temperature and pH on V. vulnificus and V. parahaemolyticus planktonic and biofilm growth. Vibrio strains were grown in triplicate at 25°, 30°, and 37°C in 96 well plates containing Modified Seawater Yeast Extract modified with CaCl 2 at pH's ranging from 5 to 9.6. AMiGA software was used to model growth curves using Gaussian process regression. The effects of temperature and pH were evaluated using randomized complete block analysis of variance, and the growth rates of V. parahaemolyticus and V. vulnificus were modeled using the interpolation fit on the MatLab Curve Fitting Toolbox. Different optimal conditions involving temperature and pH were observed for planktonic and biofilm Vibrio growth within‐ and between‐species. This study showed that temperature and pH factors significantly affect Vibrio planktonic growth rates and V. parahaemolyticus biofilm formation. Therefore, pH effects must be added to the Vibrio growth modeling efforts to better predict Vibrio risk in estuarine and coastal zones that can potentially experience the cooccurrence of Vibrio and harmful algal bloom outbreak events.

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

“…To our knowledge, no recent studies have evaluated the impact of salt on the adhesion and formation of biofilms by V. vulnificus. On the other hand, the study by Velez et al (2023) showed higher biofilm production by several clinical and environmental strains of V. vulnificus and V. parahaemolyticus at acidic pH values. Çam and Brinkmeyer (2020) confirmed these observations and also demonstrated a strong correlation between the concentration of iron in the growth medium and the production of biofilms by V. vulnificus.…”

“…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.…”

A Global Analysis of Climate Change and the Impacts on Oyster Diseases

“…These two bacteria are most successful in environments with a pH level of 7.0-7.5, and their effectiveness decreases as the pH level drops. Bacterial cell membranes and enzymes are also at risk of being damaged by acidic seawater, reducing the bacteria's ability to cause harm [139][140][141].…”