Growth response of Vibrio cholerae O1 and V. cholerae non O1/non O139 strains to algae extracts from stream water in far north Cameroon

Abstract

Background and Objectives: Vibrio cholerae O1 or non O1/non O139 is found in water ecosystems where it colonizes phytoplankton and has different lifestyle. This study aimed to investigate the impact of some algae extracts on the survival/growth of both V. cholerae strains. Materials and Methods: Algae extracts consisting of three fractions, F1 containing chlorophyll-a, F2 containing chlorophyll-b, and F3 containing carotenoids, and raw extract (RAE) were obtained from the algal bloom collected in the Kaliao stream (Maroua, Cameroon). The survival and growth of V. cholerae O1 and V. cholerae non O1/non O139, in microcosms consisting of sterile saline with these extracts and peptone (PEP) respectively added at concentrations of 0.01, 0.05 and 0.1 mg/L, and 50/50 mixtures F1+F2, F2+F3, and F2+PEP at a concentration 0.05 mg/L, were compared during a 24h experiment. Results: The microcosms F2 and RAE did not support the growth of O1 strain; V. cholerae non O1/non O139 count in all algae extract microcosms ranging from 3.97 log (CFU/mL) to 5.2 log (CFU/mL). In all PEP microcosms, the counts of both strains reached an uncountable value. Microcosms F1+F2 and F2+F3 supported the growth of V. cholerae O1 and V. cholerae non-O1/nonO139 strains. Conclusion: The algae compounds showed strain-specific effect on the growth of V. cholerae.

Keywords

• Vibrio cholerae;
• Algae;
• Survival;
• Water;
• Chlorophyll;
• Carotenoids