Diversity of Vibrio spp in Karstic Coastal Marshes in the Yucatan Peninsula

Abstract

Coastal bodies of water formed by the combination of seawater, underground rivers and rainwater comprise the systems with the greatest solar energy flow and biomass production on the planet. These characteristics make them reservoirs for a large number species, mainly microorganisms. Bacteria of the genus Vibrio are natural inhabitants of these environments and their presence is determined by variations in the nutrient, temperature and salinity cycles generated by the seasonal hydrologic behavior of these lagoon systems. This study determined the diversity of the genus Vibrio in 4 coastal bodies of water on the Yucatan Peninsula (Celestun Lagoon, Chelem Lagoon, Rosada Lagoon and Sabancuy Estuary). Using the molecular technique of 454 pyrosequencing, DNA extracted from water samples was analyzed and 32,807 reads were obtained belonging to over 20 culturable species of the genus Vibrio and related genera. OTU (operational taxonomic unit) richness and Chao2 and Shannon Weaver diversity indices were obtained with the database from this technique. Physicochemical and environmental parameters were determined and correlated with Vibrio diversity measured in OTUs.

Fig 1. Rarefaction curve at 0.97 similarity of water samples from 4 coastal lagoons: Celestun (CE), Chelem (CH), Laguna Rosada (LR) and Sabancuy (SA); in the two culture conditions: CS (water samples grown tryptone soy broth + 3% NaCl) and SS (water samples cultured in tryptone soy broth).

Fig 2. Halophilicity of Vibrio species in the four coastal lagoons analyzed: Rosada lagoon (LR); Chelem (CH); Celestun (CE) and Sabancuy (SA). + NaCl (T.C.S. broth + 3% NaCl);—NaCl (T.C.S.).

% of OUT’s is referred to the total number of OTU´s classified within the genus Vibrio for each lagoon

Fig 3. Effectiveness of the culture medium for the isolation of the family Vibrionaceae in four coastal lagoons: Rosada lagoon (LR); Chelem (CH); Celestun (CE) and Sabancuy (SA).

CS (water samples cultured in tryptone soya broth + 3% NaCl). SS (water samples cultured in tryptone soy broth).

Fig 4. Prevalence of Vibrio spp in coastal lagoons of the Yucatan Peninsula.

Fig 5. Taxonomic structure of the genus Vibrio in the four coastal lagoons studied: Rosada lagoon (LR) Chelem (CH); Celestun (CE) and Sabancuy (SA).

Fig 6. Heat map based on Jaccard at 0.97 similarity of the prevalence of Vibrio spp in the 4 coastal lagoons: Chelem (CH), Sabancuy (SA), Laguna Rosada (LR) and Celestun (CE) in two culture conditions: tryptone soy + 3% NaCl (CS) and tryptone soya (SS).