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Updated: Jun 18, 2026
A Neonatal Imaging Model of Gram-Negative Bacterial Sepsis
Published on: August 12, 2020
Neonatal mice as models for Cronobacter sakazakii infection in infants
Arena N Richardson1, Sonya Lambert, Mary Alice Smith
1Department of Environmental Health Science, University of Georgia, Athens, Georgia 30602-2102, USA.
Insights
Cronobacter sakazakii poses a risk to infants through contaminated formula. CD-1 mice showed the highest susceptibility to this pathogen, indicating potential differences in host response.
Area of Science:
- Microbiology
- Immunology
- Pathogen Research
Background:
- Cronobacter sakazakii is an opportunistic pathogen found in powdered infant formulas.
- Infections can cause severe illness, including meningitis and death, particularly in vulnerable infants.
Purpose of the Study:
- To compare the susceptibility of three mouse strains (BALB/c, C57BL/6, CD-1) to Cronobacter sakazakii (C. sakazakii) strain MNW2.
- To evaluate the impact of C. sakazakii infection on different mouse models.
Main Methods:
- Timed-pregnant CD-1 mice were used to obtain pups on postnatal day 3.5.
- Pups received varying doses (10^2 to 10^11 CFU) of C. sakazakii in reconstituted formula.
- Mice were monitored for morbidity and mortality; brains, livers, and ceca were analyzed post-euthanasia.
Main Results:
- C. sakazakii was successfully isolated from the brains, livers, and ceca of all three mouse strains.
- The CD-1 mouse strain exhibited the highest susceptibility.
- The lowest infectious dose and lethal dose for C. sakazakii were both observed at 10^2 CFU in CD-1 mice.
Conclusions:
- Mouse strain significantly influences susceptibility to Cronobacter sakazakii infection.
- CD-1 mice are a highly susceptible model for studying C. sakazakii pathogenesis.
- Further research into host-pathogen interactions in different mouse models is warranted.
Abstract:
Cronobacter sakazakii is an opportunistic pathogen that has been isolated from powdered infant formulas. C. sakazakii infection can result in serious illnesses such as bacteremia, septicemia, meningitis, and death in at-risk infants who are orally fed contaminated reconstituted powdered infant formulas. The objective of this study was to compare the susceptibilities of BALB/c, C57BL/6, and CD-1 mice to C. sakazakii strain MNW2. We acquired timed-pregnant CD-1 mice and allowed them to give birth naturally. On postnatal day 3.5, each pup was administered a total dose of approximately 10(2) to 10(11) CFU C. sakazakii strain MNW2 in reconstituted powdered infant formula. Mice were observed twice daily for morbidity and mortality. At postnatal day 10.5, the remaining pups were euthanized, and brain, liver, and cecum were excised and analyzed for the presence of C. sakazakii. C. sakazakii was isolated from brains, livers, and ceca in all three mouse strains. The CD-1 mouse strain was the most susceptible of the three, with the lowest infectious dose (10(2) CFU) and the lowest lethal dose (also 10(2) CFU).
