Studies On The Correlation Between Adherence Of Klebsiella Pneumoniae To Lung Epithelial Cells And Its Virulence

Klebsiella pneumoniae is an opportunistic pathogen that frequently causes nosocomial infections, mainly in immunocompromised patients. K. pneumoniae infections range from mild urinary infections to severe bacteremia and pneumonia with a high rate of mortality and morbidity. Pulmonary infections due to K. pneumoniae are often characterized by a rapid progressive clinical course complicated by lung abscesses and multilobular involvement which leaves little time to establish an effective antibiotic treatment. This project aims at searching for the relationship between the adherent abilities of the klebsiella pneumoniae to the human airway epithelial cells and the virulence of the Klebsiella pneumoniae to the mice. Also we investigate the protective effect of human neutrophil α-defensins on a murine model of respiratory infections induced by Klebsiella pneumoniae.In the first study, the klebsiella pneumoniae clinical isolates K4, K5, K7and K10 are incubated respectively with human airway epithelial cells A549 at ratio of 100:1 for 2 hours. After incubation, the wells were washed three times with PBS and adherent bacteria were released by the addition of 1% Triton X-100 and quantified by plating appropriate dilutions on LB agar plates. In the research of murine model, mice were anesthetized and intubated intratracheally using a blunt-ended feeding needle. Approximately 10~9 cfu of K.pneumoniae from an early-log phase broth culture were suspended in 25ul PBS and inoculated through...