Evaluación estacional de la presencia de bacterias del género vibrio en las entradas de agua en camaroneras en la zona de El Oro.

Abstract

Vibrio is a genus of harmful bacteria that has been one of the most studied worldwide due to its high incidence in aquaculture cultures, processed foods, and others. In white shrimp farming, the condition is known as "vibriosis", when it reaches a high bacterial load, it affects the organisms' immune system, becoming noticeable both externally and internally; this disease can occur in various phases of the crop, affecting both larvae and juveniles, thus knowing that in the case of larvae, Vibrio harveyi is the main cause of the disease; Vibrio parahaemolyticus, Vibrio alginolyticus, Vibrio vulnificus, Vibrio mimicus, and others, are the main causes of diseases for the fattening phase of these organisms. The presence of these species of Vibrios and their negative effects have caused the interest of researchers to learn about their ecology and determine their incidence in water intakes for aquaculture crops, therefore it is considered necessary to determine in which months of the year of the country there is a strong presence of vibrios and to analyze its relationship with physical-chemical parameters. Due to these arguments, the present work has as main objective to evaluate seasonally the presence of bacteria of the Vibrio genus in the water inlets in shrimp farms in the province of El Oro, in order to know approximately the amount of existing bacterial load and if it is present. related to salinity and water temperature.

For the analysis of the bacterial load of the different water samples in the selected points, the CHROMagar Vibrio culture medium was used, where 100 μL of the water obtained in the points (Santa Rosa, Río Jubones, Puerto Grande, Nuevo Pilo y El Coco) was used to make direct seeding and dilutions (-1) for the count of bacteria for this the seeded plates were left to rest for 24-48 hours; the experiment was carried out during the months of April, which was designated as the winter season, and July-August, the summer season, in order to assess whether there is a difference in bacterial load. In addition, the salinity and temperature of the water samples were measured at all sampling points. At the end of the experiment period, by means of the Mann-Whitney U test, it was obtained that there are significant differences in the presence of bacteria in the stations studied. Pearson's correlation turned out to be positive with salinity for the presence of Vibrio parahaemolyticus and Vibrio alginolyticus, unlike temperature, which in this work did not show a relationship with vibrios species.

In conclusion, in the winter months there is a higher bacterial load (CFU/ml) related to salinity, since at lower salinity there was a greater presence of vibrios, especially Vibrio alginolyticus, whi