Prevalence, Distribution, and Diversity of Salmonella Strains Isolated From a Subtropical Lake

Abstract

This study investigated the prevalence, serovar distribution, antimicrobial resistance, and pulsed field gel electrophoresis (PFGE) typing of <i>Salmonella enterica</i> isolated from Lake Zapotlán, Jalisco, Mexico. Additionally, the association of the presence of <i>Salmonella</i> with physicochemical and environmental parameters was analyzed using Pearson correlation analysis and principal component analysis (PCA). <i>Salmonella</i> spp. were identified in 19 of 63 (30.15%) samples. The prevalence of <i>Salmonella</i> was positively correlated with air temperature, electrical conductivity, pH, and dissolved oxygen and negatively correlated with relative humidity, water temperature, turbidity, and precipitation. The predominant serotype identified was Agona (68.48%), followed by Weltevreden (5.26%), Typhimurium (5.26%), and serogroup B (21.05%). Overall, the highest detected antimicrobial resistance was toward colistin (73.68%), followed by sulfamethoxazole (63.15%), tetracycline (57.89%), nalidixic acid (52.63%), and trimethoprim (52.63%). All <i>Salmonella</i> strains were genetically diverse, with a total of 11 <i>Xba</i>I and four <i>Bln</i>I profiles on PFGE. The use of these two enzymes allowed differentiate strains of <i>Salmonella</i> of the same serotype. The results obtained in this study contribute to a better understanding of the <i>Salmonella</i> spp. ecology in an endorheic subtropical lake and provide information for decision makers to propose and implement effective strategies to control point and non-point sources of pathogen contamination.