Establishment of a Cryptococcus neoformans murine pneumonia combined with meningitis model by otoscope guiding intubation method / 中华传染病杂志

ABSTRACT

Objective@#To establish a Cryptococcus neoformans murine pneumonia combined with meningitis model by otoscope guiding intubation method.@*Methods@#Twenty male C57BL/C mice were randomized into two groups, including control group and infection group, with 10 mice in each group. On the experiment day, the mice were intubated by otoscope guiding. The mice in infection group were inoculated with 10 μL of fresh Cryptococcus neoformans suspension through endotracheal tube, while the mice in control group were inoculated with 10 μL of sterile saline. The general conditions were observed and the body masses were measured at 0 h, day 3, day 5, day 7 and day 10 after inoculation in each group. Three mice in each group were sacrificed at 0 h and the rest were sacrificed at day 10. The lungs, livers, spleen and brains from each mouse were aseptically collected for quantitative culture and histopathology to confirm the successful establishment of mouse model.@*Results@#Ten mice were all successfully intubated by otoscope guiding and none of the mice was dead. The concentration of inoculated bacterial solution was 2.0×109 colony-forming units (CFU)/mL. The mice were sacrificed at 0h after incubation and the lungs were collected. The pulmonary bacterial culture at baseline (0 h) was (7.84±0.13) lg CFU/g lung. No mice was dead in two groups from 0 h to day 10. The average pulmonary bacterial load in lung was (8.11±0.81) lg CFU/g at day 10, which increased 16 times comparing with baseline. The average cerebral bacterial load in brain was (4.84±0.21) lg CFU/g at day 10. The histopathologic changes in lung showed lots of Cryptococcus neoformans which invaded in the bronchi, alveoli and alveolar space. The pathology in brain showed focal Cryptococcus neoformans invasion.@*Conclusions@#Establishment of Cryptococcus neoformans murine pneumonia and meningitis model using otoscope guiding intubation method is successful. This method has the advantages of easy operation and high successful rate.