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Experimental studies on mice subcutaneously challenged with heat-killed cells of Pseudomonas aeruginosa
Abstract:
Mice were found to be generally refractory to sc challenge with heat-killed cells of Pseudomonas aeruginosa and did not die unless unusually high concentrations were employed. Approximately 38.6% of the animals receiving a single, sublethal dose of 1 X 10(10) dead cells developed black, crusty, necrotic skin lesions within 3 to 5 days. No major gross and histopathological changes were detected in internal organs. If the animals were sc administered sublethal doses of either live or dead cells of P aeruginosa 16 days prior to sc challenge, then the incidence of black lesions rose to 78.6 and 50% of the animals, respectively. Of several antineoplastic agents tested, only methotrexate significantly affected the 72-hr LD50 resulting in a drop to 1.8 X 10(9) afrom 3.4 X 10(10) cells. However, both methotrexate and actinomycin D decreased the incidence of the black lesions.
Insights
Mice developed necrotic skin lesions after Pseudomonas aeruginosa challenge. Pre-exposure to Pseudomonas aeruginosa increased lesion incidence, while certain antineoplastic agents reduced it.
Area of Science:
- Microbiology
- Immunology
- Dermatology
Background:
- Pseudomonas aeruginosa infections can cause skin manifestations.
- Understanding host responses to bacterial challenge is crucial for developing treatments.
Purpose of the Study:
- To investigate the effects of Pseudomonas aeruginosa challenge on mice.
- To evaluate the impact of pre-exposure and antineoplastic agents on lesion development.
Main Methods:
- Mice were subcutaneously challenged with heat-killed and live Pseudomonas aeruginosa cells.
- Lesion incidence and severity were recorded.
- The effects of antineoplastic agents (methotrexate, actinomycin D) were assessed.
Main Results:
- Sublethal doses of heat-killed Pseudomonas aeruginosa induced necrotic skin lesions in 38.6% of mice.
- Pre-administration of live or dead Pseudomonas aeruginosa increased lesion incidence to 78.6% and 50%, respectively.
- Methotrexate significantly reduced the 72-hour LD50, and both methotrexate and actinomycin D decreased lesion incidence.
Conclusions:
- Mice exhibit a specific susceptibility to Pseudomonas aeruginosa-induced skin necrosis.
- Prior exposure to Pseudomonas aeruginosa primes for enhanced lesion formation.
- Antineoplastic agents show potential in mitigating Pseudomonas aeruginosa-induced skin pathology.