Extraintestinal Pathogenic Escherichia coli Survives within Neutrophils

摘要: Extracellular pathogenic Escherichia coli (ExPEC) strains are common causes of a variety clinical syndromes, including urinary tract infections, abdominal nosocomial pneumonia, neonatal meningitis, and sepsis. ExPEC extracellular bacterial pathogens; therefore, the innate immune response (e.g., professional phagocytes) plays crucial role in host defense against them. Studies using model strain CP9 demonstrated that it is relatively resistant to neutrophil-mediated bactericidal activity. Although this could be due resistance phagocytosis, ability survive intracellular killing mechanisms neutrophils another possibility. Using variation invasion assay, we studied survival within peripheral blood-derived human neutrophils. Our results indicated did neutrophils, but were unable demonstrate replication occurred. This finding was not unique CP9, since when conservative assessment used, four six additional strains, an E. laboratory strain, also capable Initial studies which began decipher by able successfully activity at least partially susceptible neutrophil oxidative burst. Therefore, absolute burst mechanism survives In addition, electron microscopy showed appeared present phagosomes avoidance phagosomal uptake or subsequent escape from phagosome does appear contributes CP9's survival. These findings suggest may important virulence mechanism.