Abstract
One of the major unanswered questions regarding the presence of Listeria monocytogenes in foods is how many cells must be ingested in order to cause illness. To answer this question, studies were undertaken by using Macaca fascicularis (cynomolgus monkey) as an animal model. Healthy nonhuman primates were dosed with various concentrations of L. monocytogenes suspended in sterile whole milk. Final concentrations of 10(5), 10(7), and 10(9) total cells of the organism were used; a control was also included. Blood samples, as well as fecal and nasal specimens, were taken at various time intervals. Only animals that received 10(9) cells of L. monocytogenes became noticeably ill, with symptoms of septicemia, irritability, loss of appetite, and occasional diarrhea. Monkeys that received 10(7) and 10(9) cells shed L. monocytogenes in the feces for approximately 21 days. In monkeys that received the dose of 10(9) cells, severe lymphopenia and neutrophilia occurred within 48 h. In a separate trial, monkeys received Maalox to reduce the gastric acidity of the stomach. However, no substantial differences were observed between Maalox-treated and control monkeys.
Full text
PDF


Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Azadian B. S., Finnerty G. T., Pearson A. D. Cheese-borne listeria meningitis in immunocompetent patient. Lancet. 1989 Feb 11;1(8633):322–323. doi: 10.1016/s0140-6736(89)91326-3. [DOI] [PubMed] [Google Scholar]
- GRAY M. L., SINGH C., THORP F., Jr Abortion, stillbirth, early death of young in rabbits by listeria monocytogenes. II. Oral exposure. Proc Soc Exp Biol Med. 1955 May;89(1):169–175. doi: 10.3181/00379727-89-21747. [DOI] [PubMed] [Google Scholar]
- Heldstab A., Rüedi D. Listeriosis in an adult female chimpanzee (Pan troglodytes). J Comp Pathol. 1982 Oct;92(4):609–612. doi: 10.1016/0021-9975(82)90013-5. [DOI] [PubMed] [Google Scholar]
- Ho J. L., Shands K. N., Friedland G., Eckind P., Fraser D. W. An outbreak of type 4b Listeria monocytogenes infection involving patients from eight Boston hospitals. Arch Intern Med. 1986 Mar;146(3):520–524. [PubMed] [Google Scholar]
- Junttila J., Brander M. Listeria monocytogenes septicemia associated with consumption of salted mushrooms. Scand J Infect Dis. 1989;21(3):339–342. doi: 10.3109/00365548909035707. [DOI] [PubMed] [Google Scholar]
- McClain D., Lee W. H. Development of USDA-FSIS method for isolation of Listeria monocytogenes from raw meat and poultry. J Assoc Off Anal Chem. 1988 May-Jun;71(3):660–664. [PubMed] [Google Scholar]
- McLauchlin J., Greenwood M. H., Pini P. N. The occurrence of Listeria monocytogenes in cheese from a manufacturer associated with a case of listeriosis. Int J Food Microbiol. 1990 May;10(3-4):255–262. doi: 10.1016/0168-1605(90)90073-e. [DOI] [PubMed] [Google Scholar]
- Miettinen A., Husu J., Tuomi J. Serum antibody response to Listeria monocytogenes, listerial excretion, and clinical characteristics in experimentally infected goats. J Clin Microbiol. 1990 Feb;28(2):340–343. doi: 10.1128/jcm.28.2.340-343.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]
- OSEBOLD J. W., INOUYE T. Pathogenesis of Listeria monocytogenes infections in natural host. I. Rabbit studies. J Infect Dis. 1954 Jul-Aug;95(1):52–66. doi: 10.1093/infdis/95.1.52. [DOI] [PubMed] [Google Scholar]
- OSEBOLD J. W., INOUYE T. Pathogenesis of Listeria monocytogenes infections in natural hosts. II. Sheep studies. J Infect Dis. 1954 Jul-Aug;95(1):67–78. doi: 10.1093/infdis/95.1.67. [DOI] [PubMed] [Google Scholar]
- Pine L., Malcolm G. B., Plikaytis B. D. Listeria monocytogenes intragastric and intraperitoneal approximate 50% lethal doses for mice are comparable, but death occurs earlier by intragastric feeding. Infect Immun. 1990 Sep;58(9):2940–2945. doi: 10.1128/iai.58.9.2940-2945.1990. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Vetési F., Balsai A., Kemenes F. Proceedings: Abortion in Gray's monkey (Cercopithecus mona) associated with Listeria monocytogenes. Acta Microbiol Acad Sci Hung. 1972;19(4):441–443. [PubMed] [Google Scholar]