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Journal of Medical Microbiology Jan 2020, a versatile Gram-negative pathogen that can cause a wide range of infections, is the most common causative agent in cases of bacterial keratitis associated with... (Review)
Review
, a versatile Gram-negative pathogen that can cause a wide range of infections, is the most common causative agent in cases of bacterial keratitis associated with contact-lens use. Corneal infections with often have poor clinical outcomes and can result in long and costly treatments. During the infection process, the pathogen exploits its large genome, encoding complex regulatory networks and a wide range of virulence factors, including motility and the secretion of various proteases and toxins. Although antibiotic resistance levels in the UK are low, higher levels have been seen in some other countries. In the face of increasing antibiotic resistance, alternative therapeutic approaches such as antivirulence strategies and phage therapy are being developed. There is increasing evidence to suggest that keratitis infections are associated with a phylogenetic subgroup of isolates carrying the gene encoding the potent cytotoxin exotoxin U, one of two mutually exclusive exotoxins secreted via the type III secretion system. The mechanisms behind this association are unclear, but understanding the genetic differences that predispose to cause corneal infections may allow for the development of targeted and more effective future treatments to reduce the morbidity of keratitis. In order to minimize the risk of severe eye infections, a wide range of contact-lens disinfection solutions are available. Constant exposure to biocides at a range of concentrations, from sub-inhibitory to inhibitory, could contribute to the development of resistance to both antibiotics and disinfectants.
Topics: Contact Lenses; Drug Resistance, Bacterial; Exotoxins; Genotype; Global Health; Humans; Keratitis; Pseudomonas Infections; Pseudomonas aeruginosa; Virulence Factors
PubMed: 31750813
DOI: 10.1099/jmm.0.001110 -
Proceedings of the National Academy of... May 2022Surface sensing is a critical process that promotes the transition to a biofilm lifestyle. Several surface-sensing mechanisms have been described for a range of species,...
Surface sensing is a critical process that promotes the transition to a biofilm lifestyle. Several surface-sensing mechanisms have been described for a range of species, most involving surface appendages, such as flagella and pili. Pseudomonas aeruginosa uses the Wsp chemosensory-like signal transduction pathway to sense surfaces and promote biofilm formation. The methyl-accepting chemotaxis protein WspA recognizes an unknown surface-associated signal and initiates a phosphorylation cascade that activates the diguanylate cyclase WspR. We conducted a screen for Wsp-activating compounds and found that chemicals that impact the cell envelope induce Wsp signaling, increase intracellular c-di-GMP levels, and can promote surface attachment. To isolate the Wsp system from other P. aeruginosa surface-sensing systems, we heterologously expressed it in Escherichia coli and found it sufficient for sensing surfaces and the chemicals identified in our screen. Using well-characterized reporters for different E. coli cell envelope stress responses, we then determined that Wsp sensitivity overlapped with multiple E. coli cell envelope stress-response systems. Using mutational and CRISPRi analysis, we found that misfolded proteins in the periplasm appear to be a major stimulus of the Wsp system. Finally, we show that surface attachment appears to have an immediate, observable effect on cell envelope integrity. Collectively, our results provide experimental evidence that cell envelope stress represents an important feature of surface sensing in P. aeruginosa.
Topics: Biofilms; Cell Membrane; Cell Wall; Periplasm; Pseudomonas aeruginosa
PubMed: 35476526
DOI: 10.1073/pnas.2117633119 -
International Journal of Molecular... Aug 2021() is an opportunistic pathogen showing a high intrinsic resistance to a wide variety of antibiotics. It causes nosocomial infections that are particularly detrimental... (Review)
Review
() is an opportunistic pathogen showing a high intrinsic resistance to a wide variety of antibiotics. It causes nosocomial infections that are particularly detrimental to immunocompromised individuals and to patients suffering from cystic fibrosis. We provide a snapshot on regulatory RNAs of that impact on metabolism, pathogenicity and antibiotic susceptibility. Different experimental approaches such as in silico predictions, co-purification with the RNA chaperone Hfq as well as high-throughput RNA sequencing identified several hundreds of regulatory RNA candidates in . Notwithstanding, using in vitro and in vivo assays, the function of only a few has been revealed. Here, we focus on well-characterized small base-pairing RNAs, regulating specific target genes as well as on larger protein-binding RNAs that sequester and thereby modulate the activity of translational repressors. As the latter impact large gene networks governing metabolism, acute or chronic infections, these protein-binding RNAs in conjunction with their cognate proteins are regarded as global post-transcriptional regulators.
Topics: Bacterial Proteins; Gene Expression Regulation, Bacterial; Humans; Pseudomonas Infections; Pseudomonas aeruginosa; RNA Interference; RNA Processing, Post-Transcriptional; RNA, Bacterial; RNA-Binding Proteins
PubMed: 34445336
DOI: 10.3390/ijms22168632 -
Applied Microbiology and Biotechnology Jan 2020Chronic infections caused by Pseudomonas aeruginosa have been a major concern as their spread and mortality continue to be on the rise. These infections are majorly... (Review)
Review
Chronic infections caused by Pseudomonas aeruginosa have been a major concern as their spread and mortality continue to be on the rise. These infections are majorly attributed to biofilm formation via sequential steps where motility plays an essential role in initial attachment of bacterial cells onto biotic and abiotic surfaces, thereby contributing to multi-drug resistance among pathogens. Therefore, attenuating motility properties can be considered as highly potential for controlling P. aeruginosa biofilm formation. This strategy has employed the use of various natural and chemically synthesized compounds. The present review article explained the importance and regulation of different types of motilities properties. Furthermore, it also covered several important alternative approaches using anti-motility agents which could be helpful for controlling P. aeruginosa biofilm-associated infections. Further studies are required for in-depth understandings about the mechanisms of motilities controlling of these molecules at molecular levels.
Topics: Anti-Bacterial Agents; Bacterial Adhesion; Biofilms; Gene Expression Regulation, Bacterial; Movement; Pseudomonas Infections; Pseudomonas aeruginosa; Signal Transduction
PubMed: 31768614
DOI: 10.1007/s00253-019-10201-w -
Journal of Global Antimicrobial... Sep 2020Several studies in the Arab region have recognised the rate of nosocomial infections caused by Pseudomonas aeruginosa (P. aeruginosa), which produce β-lactamase, and... (Review)
Review
BACKGROUND
Several studies in the Arab region have recognised the rate of nosocomial infections caused by Pseudomonas aeruginosa (P. aeruginosa), which produce β-lactamase, and identified their emergence and prevalence in the region. This article reviewed molecular studies on these β-lactamase-producing P. aeruginosa during 2010-2018 in several countries of the Arab region in order to analyse the trend of rising prevalence of disease causing drug-resistant P. aeruginosa in the Arab region.
METHODS
Data from selected clinical studies during 2010-2018 on β-lactamase-producing P. aeruginosa in the Arab region were obtained from reliable scientific databases for analysis and evaluation.
RESULTS
Significant changes were found in resistance of P. aeruginosa towards certain antibiotics of the β-lactam class. There was an increasing trend in the occurrence of resistance genes in β-lactamase-producing P. aeruginosa.
CONCLUSION
This review showed that there is an increasing prevalence of β-lactamase-producing P. aeruginosa in some countries in the Arab region. This is a major cause of concern as this implies that more and more instances of multidrug resistance are emerging in this area. This leads to an overall negative impact on health concerns and amounts to increasing difficulty in combating disease. It is recommended that awareness about antibiotic use and abuse be made a priority and measures to curb unchecked use of prescription antibiotics be put into place. Effective screening methods to detect cases of resistance at their onset may be developed.
Topics: Anti-Bacterial Agents; Arabs; Drug Resistance, Multiple, Bacterial; Humans; Microbial Sensitivity Tests; Prevalence; Pseudomonas Infections; Pseudomonas aeruginosa; beta-Lactamases
PubMed: 32057979
DOI: 10.1016/j.jgar.2020.01.011 -
Pakistan Journal of Biological Sciences... Mar 2020Pseudomonas aeruginosa is a free living bacterium in widely different areas such as plants, soil, water and other moist locations. It is pathogenic to plants and humans....
BACKGROUND AND OBJECTIVE
Pseudomonas aeruginosa is a free living bacterium in widely different areas such as plants, soil, water and other moist locations. It is pathogenic to plants and humans. P. aeruginosa causes several disease symptoms to plants such as wet rot and curved leaves. The virulent bacterial viruses of P. aeruginosa were found to be of widespread occurrence in nature and isolated from widely different sources. Bacterial viruses were applied to control pathogenic bacteria in different fields and successfully. Therefore, this work aimed to study the different characteristics of P. aeruginosa lytic phage isolates. Moreover, the bio-control of P. aeruginosa by lytic phage isolates was also studied.
MATERIAL AND METHODS
Different physical and molecular characteristics were assayed and determined of P. aeruginosa lytic bacteriophages. Also, the effect of phage isolates on P. aeruginosa as a bio-control under lab condition was studied.
RESULTS
Pseudomonas aeruginosa pathogenic bacterium was isolated from a sewage water sample. Two lytic bacteriophages specific to P. aeruginosa were isolated from same sewage water sample and designated Pa1 and Pa2. Both phage isolates (Pa1 and Pa2) found to be stable in 90°C and different pH low and high levels. The total count of P. aeruginosa decreased after 48 h in broth treated with lytic phages. RAPD-PCR amplification was indicated that the two phage isolates (Pa1 and Pa2) are belonging to two different phage types.
CONCLUSION
The results of this study indicated that both lytic phage isolates could be used as a biological control agents against the plant pathogen P. aeuroginosa.
Topics: Bacteriophages; Biological Control Agents; Cytopathogenic Effect, Viral; Microbial Viability; Pseudomonas aeruginosa; Sewage; Virulence; Water Microbiology
PubMed: 32363834
DOI: 10.3923/pjbs.2020.491.500 -
Frontiers in Immunology 2021is a key pathogen of chronic infections in the lungs of cystic fibrosis patients and in patients suffering from chronic wounds of diverse etiology. In these infections... (Review)
Review
is a key pathogen of chronic infections in the lungs of cystic fibrosis patients and in patients suffering from chronic wounds of diverse etiology. In these infections the bacteria congregate in biofilms and cannot be eradicated by standard antibiotic treatment or host immune responses. The persistent biofilms induce a hyper inflammatory state that results in collateral damage of the adjacent host tissue. The host fails to eradicate the biofilm infection, resulting in hindered remodeling and healing. In the present review we describe our current understanding of innate and adaptive immune responses elicited by biofilms in cystic fibrosis lung infections and chronic wounds. This includes the mechanisms that are involved in the activation of the immune responses, as well as the effector functions, the antimicrobial components and the associated tissue destruction. The mechanisms by which the biofilms evade immune responses, and potential treatment targets of the immune response are also discussed.
Topics: Adaptive Immunity; Animals; Anti-Bacterial Agents; Biofilms; Host-Pathogen Interactions; Humans; Immunity, Innate; Immunization, Passive; Immunologic Factors; Pseudomonas Infections; Pseudomonas aeruginosa
PubMed: 33692800
DOI: 10.3389/fimmu.2021.625597 -
Toxins Sep 2020is the most common human opportunistic pathogen associated with nosocomial diseases. In 2017, the World Health Organization has classified as a critical agent... (Review)
Review
is the most common human opportunistic pathogen associated with nosocomial diseases. In 2017, the World Health Organization has classified as a critical agent threatening human health, and for which the development of new treatments is urgently necessary. One interesting avenue is to target virulence factors to understand pathogenicity. Thus, characterising exoproteins of is a hot research topic and proteomics is a powerful approach that provides important information to gain insights on bacterial virulence. The aim of this review is to focus on the contribution of proteomics to the studies of exoproteins, highlighting its relevance in the discovery of virulence factors, post-translational modifications on exoproteins and host-pathogen relationships.
Topics: Bacterial Proteins; Host-Pathogen Interactions; Protein Processing, Post-Translational; Proteome; Proteomics; Pseudomonas aeruginosa; Virulence; Virulence Factors
PubMed: 32899849
DOI: 10.3390/toxins12090571 -
Journal of Drug Targeting Mar 2021is a gram-negative bacterium that exists in various ecosystems, causing severe infections in patients with AIDS or cystic fibrosis. can form biofilm on a variety of... (Review)
Review
is a gram-negative bacterium that exists in various ecosystems, causing severe infections in patients with AIDS or cystic fibrosis. can form biofilm on a variety of surfaces, whereby the bacteria produce defensive substances and enhance antibiotic-resistance, making themselves more adaptable to hostile environments. resistance represents one of the main causes of infection-related morbidity and mortality at a global level. Iron is required for the growth of biofilm. This review summarises how the iron metabolism contributes to develop biofilm, and more importantly, it may provide some references for the clinic to achieve novel anti-biofilm therapeutics by targeting iron activities.
Topics: Acquired Immunodeficiency Syndrome; Anti-Bacterial Agents; Biofilms; Cystic Fibrosis; Drug Resistance, Bacterial; Humans; Iron; Pseudomonas Infections; Pseudomonas aeruginosa
PubMed: 32969723
DOI: 10.1080/1061186X.2020.1824235 -
Current Opinion in Microbiology Feb 2020Chronic infections often contain complex polymicrobial communities that are recalcitrant to antibiotic treatment. The pathogens associated with these infectious... (Review)
Review
Chronic infections often contain complex polymicrobial communities that are recalcitrant to antibiotic treatment. The pathogens associated with these infectious communities are often studied in pure culture for their ability to cause disease. However, recent studies have begun to focus on the role of polymicrobial interactions in disease outcomes. Pseudomonas aeruginosa can colonize patients with chronic lung diseases for years and sometimes even decades. During these prolonged infections, P. aeruginosa encounters a plethora of other microbes including bacteria, fungi, and viruses. The interactions between these microbes can vary greatly, ranging from antagonistic to synergistic depending on specific host and microbe-associated contexts. These additional layers of complexity associated with chronic P. aeruginosa infections must be considered in future studies in order to fully understand the physiology of infection. Such studies focusing on the entire infectious community rather than individual species may ultimately lead to more effective therapeutic design for persistent polymicrobial infections.
Topics: Animals; Bacteria; Humans; Lung; Lung Diseases; Microbial Interactions; Microbiota; Pseudomonas aeruginosa
PubMed: 32062024
DOI: 10.1016/j.mib.2020.01.014