Molecular analysis of Salmonella entriditis isolates from the Caribbean pulsed-field gel electrophoresis

ABSTRACT

Using pulsed-field electrophoresis (PFGE), between 1987 and 1996 we analyzed Salmonella enteriditis isolates from gastroenteritis cases in four Caribbean countries Barbados, Saint Kitts and Nevis, Saint Lucia, and Trinidad and Tobago. We also determined the resistance of the isolates to 12 antimicrobial agents. Of the 129 isolates of S. enteritidis available for testing, DNA digested by XbaI revealed 13 distinctive PFGE patterns. The most prevalent XbaI PFGE patterns were group 1 (88 of 129 isolates, 68.2 percent) and group 2 (26 of 129, 20.2 percent). The patterns found among S. enteritidis isolates correlated with the geographical origin of the isolates. Of the 28 isolates from Barbados, 20 of them (71.4 percent) belonged to XbaI PFGE group 2, and of the 93 isolates from Trinidad and Tobago, 78 of them (83.9 percent) belonged to group 1. SpeI digestion of S. enteritidis genome was not as discriminatory as XbaI. Overall, of the 129 isolates, 67 of them (51.9 percent) exhibited resistance to one or more of the twelve antimicrobial agents that we tested. The prevalence of resistance was 53.8 percent for the S. enteritidis isolates tested from Trinidad and Tobago, 50.0 percent for those from Barbados, 28.6 percent for those from Saint Lucia, 100.0 percent for those from the island of Saint Kitts. Resistance was highest to triple sulfur (59 of 129, 7.8 percent), ampicillin (7 of 129, 5.4 percent), and carbamycin (5 of 129, 3.9 percent). (AU)