scholarly journals The Role of Bacterial Secretion Systems in the Virulence of Gram-Negative Airway Pathogens Associated with Cystic Fibrosis

2016 ◽  
Vol 7 ◽  
Author(s):  
Sofie Depluverez ◽  
Simon Devos ◽  
Bart Devreese
Keyword(s):  
Cystic Fibrosis ◽  
Secretion Systems ◽  
Gram Negative ◽  
Bacterial Secretion

scholarly journals Hemolysin Co-regulated Family Proteins Hcp1 and Hcp2 Contribute to Edwardsiella ictaluri Pathogenesis

2021 ◽  
Vol 8 ◽  
Author(s):  
Safak Kalindamar ◽  
Hossam Abdelhamed ◽  
Adef O. Kordon ◽  
Lesya M. Pinchuk ◽  
Attila Karsi
Keyword(s):  
Clinical Signs ◽  
Peritoneal Macrophages ◽  
Edwardsiella Ictaluri ◽  
Economic Losses ◽  
Type Vi Secretion System ◽  
Secretion Systems ◽  
Gram Negative ◽  
Ovary Cells ◽  
Bacterial Secretion

Edwardsiella ictaluri is a Gram-negative facultative intracellular pathogen causing enteric septicemia of catfish (ESC), a devastating disease resulting in significant economic losses in the U.S. catfish industry. Bacterial secretion systems are involved in many bacteria's virulence, and Type VI Secretion System (T6SS) is a critical apparatus utilized by several pathogenic Gram-negative bacteria. E. ictaluri strain 93–146 genome has a complete T6SS operon with 16 genes, but the roles of these genes are still not explored. In this research, we aimed to understand the roles of two hemolysin co-regulated family proteins, Hcp1 (EvpC) and Hcp2. To achieve this goal, single and double E. ictaluri mutants (EiΔevpC, EiΔhcp2, and EiΔevpCΔhcp2) were generated and characterized. Catfish peritoneal macrophages were able to kill EiΔhcp2 better than EiΔevpC, EiΔevpCΔhcp2, and E. ictaluri wild-type (EiWT). The attachment of EiΔhcp2 and EiΔevpCΔhcp2 to ovary cells significantly decreased compared to EiWT whereas the cell invasion rates of these mutants were the same as that of EiWT. Mutants exposed to normal catfish serum in vitro showed serum resistance. The fish challenges demonstrated that EiΔevpC and EiΔevpCΔhcp2 were attenuated completely and provided excellent protection against EiWT infection in catfish fingerlings. Interestingly, EiΔhcp2 caused higher mortality than that of EiWT in catfish fingerlings, and severe clinical signs were observed. Although fry were more susceptible to vaccination with EiΔevpC and EiΔevpCΔhcp2, their attenuation and protection were significantly higher compared to EiWT and sham groups, respectively. Taken together, our data indicated that evpC (hcp1) is involved in E. ictaluri virulence in catfish while hcp2 is involved in adhesion to epithelial cells and survival inside catfish macrophages.

scholarly journals Analysis of ATPases of putative secretion operons in the thermoacidophilic archaeon Sulfolobus solfataricus

Microbiology ◽  
2005 ◽  
Vol 151 (3) ◽  
pp. 763-773 ◽  
Author(s):  
Sonja-Verena Albers ◽  
Arnold J. M. Driessen
Keyword(s):  
Expression Patterns ◽  
Sulfolobus Solfataricus ◽  
Gene Clusters ◽  
Growth Conditions ◽  
Gram Negative Bacteria ◽  
Secretion Systems ◽  
Gram Negative ◽  
Type Iv ◽  
Encoding Gene ◽  
Bacterial Secretion

Gram-negative bacteria use a wide variety of complex mechanisms to secrete proteins across their membranes or to assemble secreted proteins into surface structures. As most archaea only possess a cytoplasmic membrane surrounded by a membrane-anchored S-layer, the organization of such complexes might be significantly different from that in Gram-negative bacteria. Five proteins of Sulfolobus solfataricus, SSO0120, SSO0572, SSO2316, SSO2387 and SSO2680, which are homologous to secretion ATPases of bacterial type II, type IV secretion systems and the type IV pili assembly machinery, were identified. The operon structures of these putative secretion systems encoding gene clusters and the expression patterns of the ATPases under different growth conditions were determined, and it was established that all five putative ATPases do show a divalent cation-dependent ATPase activity at high temperature. These results show that the archaeal secretion systems are related to the bacterial secretion systems and might be powered in a similar way.

Intrinsic role of bacterial secretion systems in phylogenetic niche conservation of Bradyrhizobium spp.

2019 ◽  
Vol 95 (11) ◽  
Author(s):  
Goutam Banerjee ◽  
Swarnendu Basak ◽  
Tathagato Roy ◽  
Pritam Chattopadhyay
Keyword(s):  
Multivariate Analysis ◽  
Secretion Systems ◽  
Free Living ◽  
Type Iv ◽  
In Silico Study ◽  
Bradyrhizobium Sp ◽  
Living Root ◽  
Bacterial Secretion ◽  
Bradyrhizobium Spp

ABSTRACT Bradyrhizobium is a biologically important bacterial genus. Different Bradyrhizobium strains exhibit distinct niche selection like free living, root nodular and stem nodular. The present in-silico study was undertaken to identify the role of bacterial secretome in the phylogenetic niche conservation (PNC) of Bradyrhizobium sp. Analysis was carried out with the publicly available 19 complete genome assembly and annotation reports. A protocol was developed to screen the secretome related genes using three different database, viz. genome, proteome and gene ortholog. This resulted into 139 orthologs that include type secretion systems (T1SS-T6SS) along with flagella (Flg), type IV pili (T4P) and tight adherence (Tad) systems. Multivariate analysis using bacterial secretome was undertaken to find out the role of these secretion systems in PNC. In free living strains, T3SS, T4SS and T6SS were completely absent. Whereas, in the stem nodulating strains, T3SS and T6SS were absent, but T4SS was found to be present. On the other hand, the T3SS was found to be present only in the root-nodulating strains. The present investigation clearly demonstrated a pattern of PNC based on the distribution of secretion system components. To the best of our knowledge, this is the first report on PNC of Bradyrhizobium using the multivariate analysis of secretome.

Structural Biology of Bacterial Secretion Systems in Gram-Negative Pathogens- Potential for New Drug Targets

2009 ◽  
Vol 9 (5) ◽  
pp. 518-547 ◽  
Author(s):  
E. Durand ◽  
D. Verger ◽  
A. Rego ◽  
V. Chandran ◽  
G. Meng ◽  
...  
Keyword(s):  
Structural Biology ◽  
Drug Targets ◽  
Secretion Systems ◽  
Gram Negative ◽  
New Drug ◽  
Bacterial Secretion

scholarly journals Clonal Clusters, Molecular Resistance Mechanisms and Virulence Factors of Gram-Negative Bacteria Isolated from Chronic Wounds in Ghana

Antibiotics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 339
Author(s):  
Denise Dekker ◽  
Frederik Pankok ◽  
Thorsten Thye ◽  
Stefan Taudien ◽  
Kwabena Oppong ◽  
...  
Keyword(s):  
Molecular Epidemiology ◽  
Virulence Factors ◽  
Iron Uptake ◽  
Chronic Wounds ◽  
Sub Saharan Africa ◽  
Gram Negative Bacteria ◽  
Beta Lactamase ◽  
Secretion Systems ◽  
Gram Negative ◽  
E Coli

Wound infections are common medical problems in sub-Saharan Africa but data on the molecular epidemiology are rare. Within this study we assessed the clonal lineages, resistance genes and virulence factors of Gram-negative bacteria isolated from Ghanaian patients with chronic wounds. From a previous study, 49 Pseudomonas aeruginosa, 21 Klebsiellapneumoniae complex members and 12 Escherichia coli were subjected to whole genome sequencing. Sequence analysis indicated high clonal diversity with only nine P. aeruginosa clusters comprising two strains each and one E. coli cluster comprising three strains with high phylogenetic relationship suggesting nosocomial transmission. Acquired beta-lactamase genes were observed in some isolates next to a broad spectrum of additional genetic resistance determinants. Phenotypical expression of extended-spectrum beta-lactamase activity in the Enterobacterales was associated with blaCTX-M-15 genes, which are frequent in Ghana. Frequently recorded virulence genes comprised genes related to invasion and iron-uptake in E. coli, genes related to adherence, iron-uptake, secretion systems and antiphagocytosis in P. aeruginosa and genes related to adherence, biofilm formation, immune evasion, iron-uptake and secretion systems in K. pneumonia complex. In summary, the study provides a piece in the puzzle of the molecular epidemiology of Gram-negative bacteria in chronic wounds in rural Ghana.

scholarly journals Systems Biology and Bile Acid Signalling in Microbiome-Host Interactions in the Cystic Fibrosis Lung

Antibiotics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 766
Author(s):  
David F. Woods ◽  
Stephanie Flynn ◽  
Jose A. Caparrós-Martín ◽  
Stephen M. Stick ◽  
F. Jerry Reen ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Bile Acids ◽  
Host Response ◽  
Signal Molecules ◽  
Therapeutic Approaches ◽  
Related Factors ◽  
Host Interactions ◽  
Important Host ◽  
Respiratory Microbiota

The study of the respiratory microbiota has revealed that the lungs of healthy and diseased individuals harbour distinct microbial communities. Imbalances in these communities can contribute to the pathogenesis of lung disease. How these imbalances occur and establish is largely unknown. This review is focused on the genetically inherited condition of Cystic Fibrosis (CF). Understanding the microbial and host-related factors that govern the establishment of chronic CF lung inflammation and pathogen colonisation is essential. Specifically, dissecting the interplay in the inflammation–pathogen–host axis. Bile acids are important host derived and microbially modified signal molecules that have been detected in CF lungs. These bile acids are associated with inflammation and restructuring of the lung microbiota linked to chronicity. This community remodelling involves a switch in the lung microbiota from a high biodiversity/low pathogen state to a low biodiversity/pathogen-dominated state. Bile acids are particularly associated with the dominance of Proteobacterial pathogens. The ability of bile acids to impact directly on both the lung microbiota and the host response offers a unifying principle underpinning the pathogenesis of CF. The modulating role of bile acids in lung microbiota dysbiosis and inflammation could offer new potential targets for designing innovative therapeutic approaches for respiratory disease.

scholarly journals Folding Control in the Path of Type 5 Secretion

Toxins ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 341
Author(s):  
Nathalie Dautin
Keyword(s):  
Protein Folding ◽  
Virulence Factors ◽  
Secretion System ◽  
Gram Negative Bacteria ◽  
Secretion Systems ◽  
Gram Negative ◽  
Final Destination ◽  
Cell Compartments ◽  
Recent Addition ◽  
Functionally Diverse

The type 5 secretion system (T5SS) is one of the more widespread secretion systems in Gram-negative bacteria. Proteins secreted by the T5SS are functionally diverse (toxins, adhesins, enzymes) and include numerous virulence factors. Mechanistically, the T5SS has long been considered the simplest of secretion systems, due to the paucity of proteins required for its functioning. Still, despite more than two decades of study, the exact process by which T5SS substrates attain their final destination and correct conformation is not totally deciphered. Moreover, the recent addition of new sub-families to the T5SS raises additional questions about this secretion mechanism. Central to the understanding of type 5 secretion is the question of protein folding, which needs to be carefully controlled in each of the bacterial cell compartments these proteins cross. Here, the biogenesis of proteins secreted by the Type 5 secretion system is discussed, with a focus on the various factors preventing or promoting protein folding during biogenesis.

Understanding the expanding role of pharmacy services in outpatient cystic fibrosis care

2021 ◽  
Author(s):  
Jeffery T. Zobell ◽  
Justin Moss ◽  
Stephanie Heuser ◽  
Lynda Roe ◽  
David C. Young
Keyword(s):  
Cystic Fibrosis ◽  
Pharmacy Services
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