Vibrio sp. and Identification of the ctx Gene of Cholera Toxin in the Mandinga Coastal Lagoon, Veracruz, Mexico

Coastal lagoons have undergone changes due to anthropogenic activities, the presence of wastewater discharges, and unsustainable practices that alter water quality, favoring the presence of pathogenic microorganisms such as <i>Vibrio</i>. This study identified the presence of the genes for zinc metalloproteinase (HA) <i>Vibrio</i> sp. and choleric toxin (<i>ctx</i>) <i>Vibrio cholerae</i>, associated with the sources of contamination in the Mandinga Coastal Lagoon (MCL). During 2017, samplings were carried out in which sources of contamination associated with anthropogenic activities were identified. At the same time, water samples were collected from which DNA was extracted and the presence/absence of the HA and <i>ctx</i> genes was detected with a PCR analysis. The HA gene was identified in the three seasons of the year, while the <i>ctx</i> gene was only present in the dry and rainy seasons. The prevalence of both genes in the study area was independent of the presence of the pollution sources identified in the area. The absence of the <i>ctx</i> gene during the northern season is associated with the variability of the physicochemical parameters typical of the season.