Chengping Hu1, Juan Jiang1, Zhen Li1, Yuanyuan Li1. 1. Department of Respiratory Medicine (Department of Respiratory and Critical Care Medicine), Key Cite of National Clinical Research Center for Respiratory Disease, Xiangya Hospital, Central South University, Changsha 410008, China.
Abstract
BACKGROUND: Acinetobacter baumannii (A. baumannii) is one of the most troublesome opportunistic pathogens associated with hospital-acquired pneumonia (HAP). It is important to be able to discriminate A. baumannii colonization from infection in its early stages so that effective antibiotics can be promptly applied. Recent studies have reported that the secretion of soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) is markedly upregulated in pneumonia and sepsis, but the expression pattern of sTREM-1 in A. baumannii colonization and infection in the lung has not been explored. METHODS: C57BL/6J male mice were intraperitoneally injected with 1% streptozotocin for 5 consecutive days to establish diabetic models. Subsequently, aerosol inhalation of A. baumannii suspension was performed in these mice to induce pulmonary colonization or infection with saline as vehicle control. Mice were sacrificed and lung tissue was harvested on days 0, 1, 3, 5 and 7 after exposure. Pharyngeal swab culture, lung homogenate culture, and H&E staining of lung tissue were performed to assess the severity of infectious inflammation. sTREM-1 expressions in serum and lung supernatants, serum procalcitonin (PCT) and C-reactive protein (CRP) concentrations were measured by ELISA. RESULTS: A. baumannii colonization and infection models were verified by pharyngeal swab culture, lung homogenate culture, and H&E staining. While sTREM-1 concentrations in mice with A. baumannii colonization remained unchanged in serum and lung supernatants, sTREM-1 expression levels in infected animals were significantly upregulated. In addition, serum sTREM-1 concentration was positively correlated with serum levels of PCT and CRP. CONCLUSIONS: Dynamic secretion of sTREM-1 is associated with the development of A. baumannii infection in the lung. Therefore, sTREM-1 expression level may be a promising biomarker for discriminating A. baumannii infection from colonization.
BACKGROUND: Acinetobacter baumannii (A. baumannii) is one of the most troublesome opportunistic pathogens associated with hospital-acquired pneumonia (HAP). It is important to be able to discriminate A. baumannii colonization from infection in its early stages so that effective antibiotics can be promptly applied. Recent studies have reported that the secretion of soluble triggering receptor expressed on myeloid cells-1 (sTREM-1) is markedly upregulated in pneumonia and sepsis, but the expression pattern of sTREM-1 in A. baumannii colonization and infection in the lung has not been explored. METHODS: C57BL/6J male mice were intraperitoneally injected with 1% streptozotocin for 5 consecutive days to establish diabetic models. Subsequently, aerosol inhalation of A. baumannii suspension was performed in these mice to induce pulmonary colonization or infection with saline as vehicle control. Mice were sacrificed and lung tissue was harvested on days 0, 1, 3, 5 and 7 after exposure. Pharyngeal swab culture, lung homogenate culture, and H&E staining of lung tissue were performed to assess the severity of infectious inflammation. sTREM-1 expressions in serum and lung supernatants, serum procalcitonin (PCT) and C-reactive protein (CRP) concentrations were measured by ELISA. RESULTS: A. baumannii colonization and infection models were verified by pharyngeal swab culture, lung homogenate culture, and H&E staining. While sTREM-1 concentrations in mice with A. baumannii colonization remained unchanged in serum and lung supernatants, sTREM-1 expression levels in infected animals were significantly upregulated. In addition, serum sTREM-1 concentration was positively correlated with serum levels of PCT and CRP. CONCLUSIONS: Dynamic secretion of sTREM-1 is associated with the development of A. baumannii infection in the lung. Therefore, sTREM-1 expression level may be a promising biomarker for discriminating A. baumannii infection from colonization.
Authors: Ji Ye Jung; Moo Suk Park; Song Ee Kim; Byung Hoon Park; Ji Young Son; Eun Young Kim; Joo Eun Lim; Sang Kook Lee; Sang Hoon Lee; Kyung Jong Lee; Young Ae Kang; Se Kyu Kim; Joon Chang; Young Sam Kim Journal: BMC Infect Dis Date: 2010-07-30 Impact factor: 3.090
Authors: Tobias M Bingold; Barbara Pullmann; Sven Sartorius; Emanuel V Geiger; Ingo Marzi; Kai Zacharowski; Heimo Wissing; Bertram Scheller Journal: Crit Care Date: 2011-04-15 Impact factor: 9.097