Core and Accessory Genome Analysis of Vibrio mimicus.

Vibrio mimicus is an emerging pathogen, mainly associated with contaminated seafood consumption. However, little is known about its evolution, biodiversity, and pathogenic potential. This study analyzes the pan-, core, and accessory genomes of nine V. mimicus strains. The core genome yielded 2424 genes in chromosome I (ChI) and 822 genes in chromosome II (ChII), with an accessory genome comprising an average of 10.9% of the whole genome for ChI and 29% for ChII. Core genome phylogenetic trees were obtained, and V. mimicus ATCC-33654 strain was the closest to the outgroup in both chromosomes. Additionally, a phylogenetic study of eight conserved genes (ftsZ, gapA, gyrB, topA, rpoA, recA, mreB, and pyrH), including Vibrio cholerae, Vibrio parilis, Vibrio metoecus, and Vibrio caribbenthicus, clearly showed clade differentiation. The main virulence genes found in ChI corresponded with type I secretion proteins, extracellular components, flagellar proteins, and potential regulators, while, in ChII, the main categories were type-I secretion proteins, chemotaxis proteins, and antibiotic resistance proteins. The accessory genome was characterized by the presence of mobile elements and toxin encoding genes in both chromosomes. Based on the genome atlas, it was possible to characterize differential regions between strains. The pan-genome of V. mimicus encompassed 3539 genes for ChI and 2355 genes for ChII. These results give us an insight into the virulence and gene content of V. mimicus, as well as constitute the first approach to its diversity.

Prevalence and virulence of Vibrio species isolated from raw shrimp from retail markets in Reynosa, Mexico.

In this study, the prevalence of Vibrio cholerae, Vibrio parahaemolyticus, Vibrio mimicus, Vibrio vulnificus and Vibrio spp. in shrimp from retail markets in Reynosa, Mexico was determined. A total of 765 isolates, identified as Vibrio spp. (59·1%), V. cholerae (17·8%), V. mimicus (6·7%) and V. parahaemolyticus (4·6%), were obtained; V. vulnificus was not detected. Most of the strains were isolated from supermarkets (48·1%), followed by street vendors (37·3%) and retail stores (14·6%). Moreover, several virulence genes were identified in V. cholerae: toxR (100%), OmpU (76·5%), hlyA (76·5%), VPI (19·9%) and tcpA (5·1%); in V. mimicus: vmh (100%), wzb (74·5%), pilF (54·9%), VPI (43·1%), OmpU (29·4%) and tdh (9·8%); and in V. parahaemolyticus: toxR (100%), tlh (100%), VP1680 (51·4%) and VPI (11·4%). These results show the low safety of this food and the potential risk to consumers' health, since this product in Mexican cuisine is sometimes served raw or semi-cooked. SIGNIFICANCE AND IMPACT OF THE STUDY: This study shows the prevalence of pathogenic Vibrio cholerae, Vibrio mimicus and Vibrio parahaemolyticus isolated from shrimp that is commercialized in Reynosa city. This could represent a risk to consumers' health, since outbreaks related to shrimp contaminated with Vibrio have been previously reported. Additionally, shrimp fishing has a major role in Mexico's economy.

Isolation and identification of Vibrio species in the Rio Bravo/Grande and water bodies from Reynosa, Tamaulipas.

The Rio Bravo (Rio Grande) adjoins various states in the Mexican region and has a great importance in water distribution in the northeast Tamaulipas (Mexico). In this work 161 strains were isolated, identified and characterized from the water samples taken from the flow of the Rio Bravo and the two inner canals that cover Reynosa city. The strains were identified as Vibrio cholerae (74·5%), Vibrio spp. (1·2%) and Vibrio mimicus (0·6%). Furthermore, the detected virulence genes in the V. cholerae strains, were the hlyA, ompU, tcpA, toxR genes in 78·3, 62·5, 15·8 and 90·8% respectively. Only the ompU and vmh genes were detected in the V. mimicus strain. These results indicate the presence of multi-toxigenic V. cholerae strains in the Rio Bravo/Grande and in the water bodies from Reynosa city, which could represent a risk for the exposed population. SIGNIFICANCE AND IMPACT OF THE STUDY: Water quality is associated with public health, as it plays an important role in the transmission and epidemiology of pathogens such as Vibrio, since this species have been responsible for human diseases around the world. This study demonstrated the presence of toxigenic Vibrio species in water bodies in Reynosa surroundings, indicating that water bodies may be a source of public health risk.