Microbial Etiology and Prognostic Factors of Ventilator-associated Pneumonia: A Multicenter Retrospective Study in Shanghai.

Background: The microbial etiology and mortality risk factors of ventilator-associated pneumonia (VAP) have not been investigated extensively in Shanghai. Methods: VAP cases were identified from the patients hospitalized during the period from 1 January 2013 to 30 December 2017 in Shanghai. The relevant data were reviewed and analyzed retrospectively. Results: One hundred ninety-four VAP cases were included in this analysis. The overall mortality rate was 32.47%. The respiratory pathogens isolated from these patients included 212 bacterial strains and 54 fungal strains. The leading pathogens were Acinetobacter baumannii (33.96%), Klebsiella pneumoniae (23.58%), Pseudomonas aeruginosa (19.81%), and Staphylococcus aureus (7.08%). Candida colonization was associated with higher mortality of VAP patients compared to those without Candida colonization (45.45% vs 28.67%, P < .05). The VAP patients with Candida colonization also showed higher prevalence of P. aeruginosa, carbapenem-resistant P. aeruginosa (CRPA), K. pneumoniae, carbapenem-resistant K. pneumoniae (CRKP), A. baumannii, and carbapenem-resistant A. baumannii (CRAB) (P < .05). VAP nonsurvivors had higher prevalence of CRPA, K. pneumoniae, CRAB, and Candida than VAP survivors (P < .05). Multivariate analysis showed that prior antibiotic use was a significant risk factor for Candida colonization, while hypertension and length of hospital stay were significant risk factors of VAP mortality (P < .05). Conclusions: The top pathogens of VAP patients in Shanghai tertiary teaching hospitals are A. baumannii, K. pneumoniae, and P. aeruginosa, with high prevalence of carbapenem resistance. Carbapenem-resistant bacterial pathogens and Candida may predict poor outcome.

Bleomycin-induced pulmonary fibrosis is attenuated by an antibody against KL-6.

BACKGROUND: Elevated levels of KL-6 are reported in the serum and/or bronchoalveolar lavage fluid (BALF) of patients with interstitial lung disease (ILD) and are useful to estimate the severity and prognosis of the disease. However, whether the anti-KL-6 antibody could attenuate pulmonary fibrosis remains unclear. OBJECTIVES: This study aims to investigate the therapeutic effects and mechanisms of anti-KL-6 antibody on bleomycin-induced pulmonary fibrosis. METHODS: A mouse model of pulmonary fibrosis was established by intratracheal injection of bleomycin (5 mg/kg). Mouse received anti-KL-6 antibody (20 ug/day, once a day) from day 7 to 21 after bleomycin injection. The effects of anti-KL-6 antibody were evaluated by pathological examination, measuring hydroxyproline measurements in lung tissues, leukocyte counts in BALF and the expression of collagen type I and type III using qRT-PCR. The expression of profibrotic cytokine (transforming growth factor-ß1, TGF-ß1), antifibrotic cytokine (hepatocyte growth factor, HGF), and KL-6 in lung tissues were analyzed by ELISA. The apoptosis of epithelial cell was examined by TUNEL staining. RESULTS: Anti-KL-6 antibody significantly reduced the number of alveolar inflammatory leukocytes (total and differential counts) in BALF of mice with bleomycin-induced pulmonary fibrosis as well as the content of hydroxyproline in the lung tissues. Treatment with anti-KL-6 antibody downregulated the expression of collagen type I, TGF-ß1 and KL-6, upregulated the expression of HGF and inhibited the apoptosis of epithelial cells. CONCLUSIONS: These findings indicated the anti-KL-6 antibody may potentially be developed as a useful inhibitor of pulmonary fibrosis.