Interactions of Enteric Bacteria with American Cockroaches (periplaneta Americana) and Pharaoh Ants (monomorium Pharaonis)

of Dissertation Presented to the Graduate School of the University of Florida in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy INTERACTIONS OF ENTERIC BACTERIA WITH AMERICAN COCKROACHES (Periplaneta americana) AND PHARAOH ANTS (Monomorium pharaonis) By Deanna Branscome August 2004 Chair: Philip G. Koehler Major Department: Entomology and Nematology Microscopic examination of cross sectioned American cockroach pronota revealed the following structures from top to bottom: an external wax layer (~1 to 3 μm), an inner exocuticle (~2 μm), a lamellate sponge-like endocuticle (~24 μm), a gap (~2 μm) and an inner/ventral layer of transparent cuticle (~6 μm). Additionally, globular material between the dorsal and ventral cuticle was revealed, between which were two brown ovoids, identified as attachment points for the prothoracic legs. Interaction of cuticle with enteric bacteria was also investigated. Pronota of American cockroaches were inoculated with 6.0 x 10 cells and incubated for 24, 48 and 72 h. No Salmonella enterica were recovered from pronota processed in deionized water. However, viable cells were recovered from the stock S. enterica solution at all time periods. Scanning electron microscopy of pronota and tarsi fixed with osmium tetroxide vapors revealed few (<60) bacteria on pronota and none on tarsi. However, on one