Project description:Biofilms are a communal of one or several kinds of microorganisms that growing on of both non-living and biotic surfaces by the production of multi-layers high-abundance extracellular matrix (ECM) to survive in the harsh environments (1-4). Biofilms consist of 85% (by volume) of matrix materials and 15% microbial cells (5). Biofilm ECM, consists of proteins, polysaccharides and/or extracellular DNAs, is important for biofilm integrity that increases environmental adaptability and induces antimicrobial resistance (6-7). Surface-adherent (sessile) bacteria in biofilms are more difficult to eradicate as minimum inhibitory concentrations (MICs) of antibiotics against bacterial biofilms is 100-1000 folds higher than the free living (planktonic) form that resulting in recurrent infections (8). Biofilms also possibly form nidus at the surface for the attachment of other pathogens lead to biofilms of multiple bacteria or multi-organisms (9ref). The communication, among organisms within biofilm, controls density of cell population refers to as “quorum sensing” (10) and different combinations of organisms in biofilms with either multiple bacteria or multi-species might induce different biofilm properties. While catheter-related colonization of Gram-positive bacteria from skin microbiota such as Streptococcus spp. and Staphylococcus spp. is common, biofilms in the inner lumen of catheter consist of both Gram-positive and Gram-negative bacteria. Because i) translocation of gut microbiota (eg. Enterococcus spp., Gram-negative bacteria and Candida albicans) into blood circulation during sepsis is one of the common causes of severe sepsis , ii) mixed systemic infection between bacteria and Candida spp. is even more severe than the infection by each organism in separation and iii) biofilms could be formed during bacteremia and fungemia, the biofilms from mixed species between bacteria and Candida spp. during sepsis is possible. In addition, central venous catheter-related candidiasis is common in intensive care units (ICU) patients refer to as “Candida catheter-related bloodstream infection (CRCBSI)”. Moreover, synergistic interaction between Candida albicans and several Gram-negative bacteria such as Escherichia coli (in peritonitis), Pseudomonas aeruginosa (in cystic fibrosis and ventilation associated pneumonia) and Acinetobacter baumannii (in ventilation associated pneumonia) has been mentioned. Hence, the collaboration between bacteria and Candida spp. might affect biofilm production as C. albicans in coexistence with the sessile microbes possibly enhance biofilms production that is detectable by crystal violet color (16,7). It is interesting to note that C. albicans are normal microbiota in human intestine and gut-translocation from intestine into blood circulation during severe sepsis (gut leakage) is demonstrated. Furthermore, both Gram-negative bacteria and C. albicans are the most and the second most predominant intestinal human microbiota, respectively, in which the natural interactions between these organisms is possible. Accordingly, catheter-related bacteremia is common among patients in ICU. Gut translocation of Candida spp. during sepsis, due to gut leakage, might induce the collaboration between bacteria and fungi results in persistent infection (20-21Chen L, 2011, 66//Wu H, 2015, 1, IJOS). Although the understanding in the interaction between organisms in biofilms should be beneficial for eradication strategies, the data of biofilms from the combination between gut-derived bacteria and fungi is still limited. As such, production of exo-polymers for biofilm-forming is a pathogenic virulent factor because biofilms is one of the important defend-mechanisms against host immune responses and antibiotics. Because i) antibiotic resistance caused by biofilm is a current serious medical problem , ii) the eradication of both bacterial and fungal biofilms is difficult and iii) antimicrobial treatment without biofilms-removal resulting in recurrent or persistent infection (23ref), biofilm prevention agent is needed (2410). Here, we explored i) the interaction between Gram-negative bacteria and C. albicans, in vitro, ii) macrophage responses against biofilm components, iii) biofilms in catheter-insertion mouse model and an evaluation on an interesting anti-biofilm.

Project description:Abstract BACKGROUND: Gene expression profiling (GEP) in cells obtained from peripheral blood has demonstrated to be a very useful approach for biomarker discovery and for studying molecular pathogenesis of prevalent diseases. While there is limited literature availble on gene expression markers associated to Chronic Obstructive Pulmonary Disease (COPD), the transcriptomic picture associated to critical respiratory illness in this disease is not known to the present moment. RESULTS: By using Agilent microarray chips, we have profiled gene expression signatures in whole blood of 28 COPD patients hospitalized with distinct degree of respiratory compromise.12 of them needed of admission to the ICU, while 16 were admitted to the Respiratory Medicine Service. GeneSpring GX 11.0 software was used for performing statistical comparison of transcript levels between ICU and non ICU patients. Ingenuity pathway analysis 8.5 (IPA) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) were employed to select, annotate and visualize genes by function and pathway (gene ontology). T-test evidenced 1501 genes differentially expressed between ICU and non ICU patients. IPA and KEGG analysis of the most representative biological functions revealed that ICU patients showed increased levels of neutrohil gene transcripts, being [cathepsin G (CTSG)], [elastase, neutrophil expressed (ELANE)], [proteinase 3 (PRTN3)], [myeloperoxidase (MPO)], [cathepsin D (CTSD)], [defensin, alpha 3, neutrophil-specific (DEFA3)], azurocidin 1 (AZU1)], [bactericidal/permeability-increasing protein (BPI)] the most representative ones. Proteins codified by these genes form part of the azurophilic granules of neutrophils and are involved in both antimicrobial defence and tissue damage. This ?neutrophil signature? was paralleled by necessity of advanced respiratory and vital support, and presence of bacterial infection. CONCLUSION: study of transcriptomic signatures in blood suggests a central role of neutrophil proteases in COPD patients with critical respiratory illness. Measurement / modulation of the expression of these genes could represent an option for clinical monitoring and treatment of severe COPD exacerbations. Keywords: COPD, critical, expression, gene, microarray, neutrophil, proteases.

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