Detection and elimination of Proteus vulgaris and Klebsiella pneumoniae in nude mice

Nude mice are immunodeficient, commonly used model organisms for studying human diseases. Despite the high purchase price and maintenance cost of these animals, few studies have aimed to eradicate inevitable infectious complications which may arise during in-vivo studies. The current project is a practical guideline for detecting and elimination of possible infections developed in nude mice.

Followed by transplantation of human leukemic cell lines into C57BL/6 nude mice, body weights were monitored daily. After a sudden death of 7 mice during 4 consecutive days, all beddings were discarded and cages, food and water bottles were disinfected immediately. Automated blood culture analyses were carried out using radiometric BACTEC systems, and specific antibiotics were administered based on applied microbial growth inhibition assays.

Proteus vulgaris and Klebsiella pneumoniae were identified, respectively, according to the radiometric assays. According to the antimicrobial susceptibility tests, 132mg/kg ciprofloxacin was administered orally for 2 weeks, followed by 500mg/kg cefixime for one week. Meanwhile, low-dose cefixime (132 mg/kg) was applied as a prophylactic treatment. Automated blood cultures showed elimination of both bacterial infections followed by demand treatments. Low-dose antibiotic prophylaxis saved uninfected mice from developing infections.

Results showed that precise monitoring of nude mice health conditions help early detection of the possibly grown infections. Ciprofloxacin and cefixime are the antibiotics of choice for eradication of Proteus vulgaris and Klebsiella pneumoniae. On the other hand, low-dose antibiotic prophylactic treatment may rescue these expensive animals from possible infections and provide suitable environment for performing in-vivo experiments.