Abstract:

Objective To investigate the role of leukocyte phagocytosis bacterium in sputum smear specimens for the diagnosis of lower respiratory tract infection. Methods A total of 175 sputum smear specimens were collected. Immune pathological（phagocytosis or accompanying）between leukocyte and bacterium was observed through the smear with Gram stain directly. Bacterial culturing and drug susceptibility were performed. The patients' clinical data were collected. The consistency was evaluated to distinguish pathogenic bacterium colonization bacterium. Results Among the 175 cases,56.6% cases were above 70 years old,85.1% cases had infection,91.4% cases received antibiotic treatment before specimen collecting. There were 51 specimens（30%） with the phenomenon of bacterial phagocytosis or accompanying by leucocytes. The consistency with the results of culturing（84.3%） was higher than those without the phenomenon of bacterial phagocytosis or accompanying by leucocytes（58.1%,P<0.05）,and the diagnosis rate of pathogenic bacteria was higher as well （92.2% and 38.7%,P<0.05）. Conclusions Bacterial phagocytosis or accompanying by leucocytes in sputum smear specimens plays a role for the diagnosis of lower respiratory tract infection.

Key words: Sputum smear, Leukocyte phagocytosis bacterium, Bacterial culturing, Pathogenic bacterium, Colonization bacterium