Project description:Klebsiella pneumoniae is an antibiotic-resistant bacteria associated with severe infections, which has led to the search for new antimicrobial drugs to face these infections. Antimicrobial peptides (AMPs) are antimicrobials that exert anti-K. pneumoniae activity. Consequently, AMPs have been explored as a therapeutic option. However, similarly to other antimicrobials, K. pneumoniae can develop resistance against AMPs, although it is less frequent. Therefore, understanding the resistance mechanisms developed by K. pneumoniae against AMPs could aid in the design and development of more effective AMPs. This study aimed to identify via a label-free quantitative proteomic approach the resistance mechanisms involved in the resistance response of K. pneumoniae against the AMP PaDBS1R1.
Project description:The emergence and spread of polymyxin resistance, especially among Klebsiella pneumoniae isolates threaten the effective management of infections. This study profiled for polymyxin resistance mechanisms and investigated the activity of polymyxins plus vancomycin against carbapenem- and polymyxin-resistant K. pneumoniae.
Project description:Using Nanopore sequencing, our study has revealed a close correlation between genomic methylation levels and antibiotic resistance rates in Acinetobacter Baumannii. Specifically, the combined genome-wide DNA methylome and transcriptome analysis revealed the first epigenetic-based antibiotic-resistance mechanism in A. baumannii. Our findings suggest that the precise location of methylation sites along the chromosome could provide new diagnostic markers and drug targets to improve the management of multidrug-resistant A. baumannii infections.
Project description:Staphylococcus aureus is one of the most successful human pathogens. It is the leading cause of a multitude of healthcare-associated, community-acquired, and acute-to-chronic infectious diseases. Bacteria can benefit from host signals during infection. Immune cells such as monocytes are able to secrete chemokine upon facing planktonic bacteria or their products. Host immune regulatory chemokine is capable to trigger planktonic S. aureus to releases its virulence factor to evade the immune response. Chemokine binding may facilitate immune evasion by S. aureus, however, the biofilm ability to induce chemokine secretion remains unknown. Also, Understanding the immune response to biofilms is critical for developing effective diagnostics and treatments for biofilm associated infections, as bacteria in biofilms differ in their resistance to antibiotics and host immune response.
Project description:The management of antibiotic-resistant, bacterial biofilm infections in chronic skin wounds is a significant clinical challenge. Despite advances in diagnosis, many patients do not derive benefit from current anti-infective/antibiotic therapies. Here we report a novel class of epoxy-tiglianes and demonstrate their antimicrobial activity (modifying bacterial growth and inducing biofilm disruption), with structure/activity relationships established against important human pathogens. In vitro, the lead candidate, EBC-1013 stimulated PKC-dependent neutrophil ROS induction and NETosis, and increased expression of wound healing associated cytokines, chemokines and antimicrobial peptides in keratinocytes and fibroblasts. In vivo, topical EBC-1013 induced rapid resolution of infection with increased matrix remodelling in acute thermal injuries. In chronically-infected, diabetic wounds, treatment induced cytokine/chemokine production, inflammatory cell recruitment and complete healing (in 6/7 wounds) with ordered keratinocyte differentiation. These results highlight a non-antibiotic approach involving contrasting, orthogonal mechanisms of action: targeted biofilm disruption and innate immune induction in the treatment of chronic wounds.
Project description:The management of antibiotic-resistant, bacterial biofilm infections in chronic skin wounds is a significant clinical challenge. Despite advances in diagnosis, many patients do not derive benefit from current anti-infective/antibiotic therapies. Here we report a novel class of epoxy-tiglianes and demonstrate their antimicrobial activity (modifying bacterial growth and inducing biofilm disruption), with structure/activity relationships established against important human pathogens. In vitro, the lead candidate, EBC-1013 stimulated PKC-dependent neutrophil ROS induction and NETosis, and increased expression of wound healing associated cytokines, chemokines and antimicrobial peptides in keratinocytes and fibroblasts. In vivo, topical EBC-1013 induced rapid resolution of infection with increased matrix remodelling in acute thermal injuries. In chronically-infected, diabetic wounds, treatment induced cytokine/chemokine production, inflammatory cell recruitment and complete healing (in 6/7 wounds) with ordered keratinocyte differentiation. These results highlight a non-antibiotic approach involving contrasting, orthogonal mechanisms of action: targeted biofilm disruption and innate immune induction in the treatment of chronic wounds.
Project description:Recent progress in unbiased metagenomic next-generation sequencing (mNGS) allows simultaneous examination of microbial and host genetic material in a single test. Leveraging affordable bronchoalveolar lavage fluid (BALF) mNGS data, we employed machine learning to create a diagnostic approach distinguishing lung cancer from pulmonary infections, conditions prone to misdiagnosis in clinical settings. This prospective study analyzed BALF-mNGS data from lung cancer and pulmonary infection patients, delineating differences in DNA/RNA microbial composition, bacteriophage abundances, and host responses, including gene expression, transposable element levels, immune cell composition, and tumor fraction derived from copy number variation (CNV). Integrating these metrics into a host/microbe metagenomics-driven machine learning model (Model VI) demonstrated robustness, achieving an AUC of 0.87 (95% CI = 0.857-0.883), sensitivity = 73.8%, and specificity = 84.5% in the training cohort, and an AUC of 0.831 (95% CI = 0.819-0.843), sensitivity = 67.1%, and specificity = 94.4% in the validation cohort for distinguishing lung cancer from pulmonary infections. The application of a rule-in and rule-out strategy-based composite predictive model significantly enhances accuracy (ACC) in distinguishing between lung cancer and tuberculosis (ACC=0.913), fungal infection (ACC=0.955), and bacterial infection (ACC=0.836). These findings highlight the potential of cost-effective mNGS-based analysis as a valuable tool for early differentiation between lung cancer and pulmonary infections, offering significant benefits through a single comprehensive testing.
Project description:Staphylococcus aureus has been recognized as an important cause of human disease for more than 100 years. Resistance to multiple classes of antibiotics is becoming an increasingly difficult problem in the management of methicillin-resistant S. aureus (MRSA) and vancomycin-intermediate resistant S. aureus (VISA) infections. One approach to the MRSA and VISA problem, involves the discovery and development of new natural antimicrobials. The antimicrobial properties of essential oils of plant origin have been recognized for many years. In this study 0.1% of commercial cold pressed terpeneless Valencia orange oil (CPV) showed inhibitory and lytic activity against MRSA and VISA. To identify the mechanisms of action of CPV genomic response of CPV treated MRSA was analyzed by transcriptional profiling. Results showed alteration in the expression of cell wall peptidoglycan biosynthesis associated genes in the CPV treated cells. Transmission electron microscopic observation of CPV treated MRSA cells exhibited cell wall damage and cell lysis. Overall results of this study suggest that CPV may be a potential anti-staphylococcal agent for MRSA.
Project description:Antimicrobial resistance (AMR) is an increasing challenge for therapy and management of bacterial infections. Currently, antimicrobial resistance detection relies on phenotypic assays, which are performed independently of species identification. On the contrary, phenotypic prediction from molecular data using genomics is gaining interest in clinical microbiology and might become a serious alternative in the future. Although, in general protein analysis should be superior to genomics for phenotypic prediction, no untargeted proteomics workflow specifically related to AMR detection has been proposed so far. In this study, we present a universal proteomics workflow to detect the bacterial species and antimicrobial resistance related proteins in the absence of secondary antibiotic cultivation in less than 4 h from a primary culture. The method was validated using a sample cohort of 7 bacterial species and 11 AMR determinants represented by 13 protein isoforms which resulted in a sensitivity of 92 % (100 % with vancomycin inference) and a specificity of 100 % with respect to AMR determinants. This proof-of concept study demonstrates the high potential of untargeted proteomics for clinical microbiology.