Molecular analysis of Salmonella enteritidis and Typhimurium clinical and food isolates by pulsed-field gel electrophoresis in Bogotá, Colombia.

In 1997, the Microbiology Group of the Colombian Instituto Nacional de Salud set up a surveillance program with the National Public Health Laboratories to monitor the principal etiological agents responsible for acute diarrheal disease. The main goal of this study was to determine the XbaI DNA digestion patterns of clinical and food Salmonella spp. isolates recovered in Bogotá from 1997 to 2002, and related them to the susceptibility patterns to antimicrobial agents. Two hundred and twenty-four Salmonella spp. isolates were studied, 153 (63%) S. Enteritidis and 71 (37%) S. Typhimurium. Pulsed-field gel electrophoresis (PFGE) was done using the XbaI restriction enzyme and Salmonella Braenderup H9812 as the molecular weight marker. For S. Enteritidis, pattern S. En0001 was found to be prevalent in 127 (83%) isolates, 78 (61%) susceptible to the antimicrobial agents tested. For S. Typhimurium, pattern S. Typ0001 was predominant in 18 (25%) isolates with different antimicrobial resistance profiles. Patterns S. En0001 and S. Typ0001 prevailed monthly during the 6 years of the study. Data collected demonstrate that there was a dominant pattern of S. Enteritidis and S. Typhimurium circulating in clinical and food isolates in Bogotá, Colombia.