Large numbers of colonizing bacteria in the upper respiratory tract and mouth

Although multiple lung infections are quite common clinically, it is difficult to diagnose them. One is that laboratory diagnostic techniques such as certain pathogens such as viruses cannot meet clinical needs. The other is that there is a large amount of colonization of the upper respiratory tract and oral cavity due to difficulties in collecting specimens from the lower respiratory tract. The bacteria flora often changes during long-term hospitalization or antibacterial treatment. Oral sputum specimens are susceptible to contamination. The growth of multiple bacterial cultures does not indicate the existence of multiple infections. On the contrary, aseptic growth or single bacteria growth cannot Eliminate multiple infections.