Serratia marcescens Bizio
Synonymy.—Bacillus prodigiosus, Bacterium prodigiosum.
Habitat.—Water, soil, milk, foods, and various insects.
Natural hosts.—Blatta orientalis, Poland (Nicewicz et al., 1946): From intestinal tract. Italy (Spinelli and Reitano, 1932).
Blattella germanica, Canada (Heimpel and West, 1959).
Diploptera punctata, Nauphoeta cinerea, Neostylopyga rhombifolia, Panchlora nivea, Pycnoscelus surinamensis, and Supella supellectilium, U.S.A. (Roth and Willis, unpublished data, 1958): The organism was isolated and identified by Dr. Hillel Levinson, Quartermaster bacteriologist, from dead specimens found in our laboratory colonies which showed the red coloration characteristic of insects that have died with infections of S. marcescens (pl. [16], A, B).
Leucophaea maderae, U.S.A. (Levinson, personal communication, 1958): The organism was isolated from the hemolymph of living insects while attempting to determine the cause of unexplained mortality in our laboratory colony of this insect.
Leucophaea maderae or Periplaneta americana, Philippine Islands (Barber, 1912): From hemolymph.
Periplaneta americana, U.S.A. (Gier, 1947; Steinhaus, 1959).
Periplaneta australasiae and Periplaneta brunnea (Roth and Willis, unpublished data [1954]): In laboratory colonies. Isolated from suspensions of ground insects. In 1954 we received a culture of Periplaneta brunnea from the Department of Public Health, University of Minnesota. These insects began to die off rapidly and the normally lightly pigmented parts of the body became red. Dr. Hillel Levinson, Quartermaster bacteriologist, cultured Serratia marcescens from several moribund individuals. The Department of Public Health of Minnesota had at times in the past cultured S. marcescens but had discarded the cultures and was unaware that it might be surviving in the cockroach colonies (Richards, personal communication, 1954).
Periplaneta sp., U.S.A. (Olson in Roth and Willis, 1957a): Isolated from an undetermined species of Periplaneta, received in a shipment from the South, a strain of S. marcescens which was toxic to mice when administered intraperitoneally.
Experimental hosts.—Blaberus craniifer, U.S.A. (Wedberg et al., 1949): When fed in small numbers, S. marcescens increased to such an extent that the insect's extremities and upper halves of their bodies turned deep red. The insects died after this color appeared and practically pure cultures of Serratia were recovered from the reddened areas.
Blatta orientalis, Italy (Cao, 1898): Isolated from intestinal contents. Passed unchanged through the gut.
Blattella germanica, Canada (Heimpel and West, 1959): Not normally pathogenic per os; LD50 by injection, is approximately 38,000 bacteria per insect.
Periplaneta americana, U.S.A. (Gier, 1947): Organism toxic to the cockroach when injected.
Cockroaches, U.S.A. (Longfellow, 1913): Isolated from legs and viscera after feeding experiments.