In vitro inhibition of Salmonella organisms isolated from reptiles by an inactivated culture of microcin-producing Escherichia coli

Objective-To determine whether an Inactivated culture of a microcin-produci ng avian Escherichia coli was capable of killing Salmonella isolates from r eptiles In an in vitro test system. Sample Population-57 Salmonella isolate from reptiles. Procedure-A wild-type avian E coli electrotransformed with a plasmid coding for the production of microcin 24 was tested in an in vitro microassay Sys tem for its ability to kill 57 Salmonella spp isolated from reptiles. The r eptile population Included snakes, iguana, frilled lizards, turtles, other lizards, and unspecified reptiles. Results-44 of the Salmonella isolates were inhibited strongly, compared wit h the in vitro assay controls; 12 had weak Inhibition, and I was not Inhibi ted by the microcin-producing E coli. Thirteen of the 57 isolates had resis tance to at least 1 antibiotic, primarily streptomycin. There were 9 O sero groups identified in the 57 isolates, with serogroup H being the most preva lent (18 to 57). Conclusion and Clinical Relevance-Antibiotics are not recommended to elimin ate Salmonella organisms from reptiles because of the development of antibi otic resistance. Further studies are necessary to determine whether the use of microcin-producing bacteria will be effective In controlling Salmonella infections in companion reptiles.