Correlation Of Pseudomonas Aeruginosa Infection And Colonization With STREM-1

Objects: To investigate triggering receptor expressed onmyeloid cells-1(TREM-1) mRNA expression varies in respiratoryinfection and colonization. Pseudomonas aeruginosa (PA) as the mostcommon bacterial of HAP is difficult to judge the colonization orinfection from sputum culture. For a long time the secretion of airwaysampling technology can not avoid bacterial contamination fromoropharyngeal, and is time-consuming. So for a rapid, simple, sensitivedifferential diagnosis index is especially important. TREM-1is the newindex that diagnosis of early inflammatory reaction, especially in thediagnosis of infectious inflammation is of high sensitivity and specificity,and relates to the severity of the bacterial infection. The purpose of thisarticle is to investigate TREM-1mRNA expression and sTREM-1variesin respiratory infection and colonization, and to discuss the correlation ofTREM-1with pneumonia and respiratory colonization by PA. This studydeals with the judgment of infection and colonization, early warning ofthe infection, reaction clinical outcomes and guide the prescription ofantibiotics. Methods:The pneumonia model was made by thyrocricoidpuncture injecting PA. The rats randomly divided into lung infectiongroup, oropharynx colonization group and the control group. Each group subdivided into3,9,24hours post injection. At serial time points in eachgroup, animals were sacrificed, and tissues of lung was harvested todetect the expression of TREM-1mRNA by using reverse transcriptionpolymerase chain reaction (RT-PCR). ELISA were employed to detectsTREM-1, CRP and PCT from the serum. The inflammation scope anddegree were compared by lung histopathology. Meanwhile, the lunghomogenate colonies count was used in each group and throat swabculture was utilize in colonization group. All statistical analyses werecompleted with SPSS17.0version software. Descriptive results werereported as mean±SD. All data were analyzed with ANOVA, and thelinear relation was analyzed with Pearson correlation analysis. Results:Expression of TREM-1mRNA was markedly up-regulated in infectiongroup of each time point compared with the other two groups, and rised at3hours, arrived the peak at9hours, droped at24hours. The colonizationand control group were no significant differences in comparison.Expression of sTREM-1, CRP and PCT were also markedly up-regulatedin infection group of each time point compared with the other two groups.CRP and PCT were positively correlated with TREM-1, respectively (r=0.86and0.75). The lung tissue pathology change was more serious ininfection group at9hours compared with3,24hours. The alveolar andpulmonary interstitial structure were normal in the colonization andcontrol group. The lung tissues of all the infection group were cultivated pseudomonas aeruginosa, and the lung homogenate colonies countexceed105CFU/g. But the colonization and control group were notcultivated bacteria. The throat swab culture was normal respiratory tractflora and PA growth in the colonization group. Conclusions: Theexpressions of lung TREM-1mRNA and serum sTREM-1markedlyincrease compared with colonization and control group in pulmonaryinfection by PA. Detection of TREM-1will contribute to identify theinfection and colonization induced by PA. The expressions of lungTREM-1mRNA and serum sTREM-1relate to the lung inflammationdegree in pulmonary infection. Detection of TREM-1has instructmeaning to judge the prognosis of infectious disease. The variation levelof serum sTREM-1and inflammation indexes CRP, PCT have highlypositive correlation in pneumonia by PA. sTREM-1has importantsignificance in PA infection.