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Microbial Pathogenesis Nov 2023Gram-negative bacteria are infectious and life-threatening agents after hematopoietic stem cell transplantation (HSCT). So, this study aimed to investigate the... (Review)
Review
Gram-negative bacteria are infectious and life-threatening agents after hematopoietic stem cell transplantation (HSCT). So, this study aimed to investigate the prevalence of Pseudomonas aeruginosa and its antibiotic resistance in patients who have received Hematopoietic Stem-Cell Transplantation through a systematic review. The systematic search was done with key words; Pseudomonas aeruginosa, hematopoietic stem cell transplantation from 2000 to the end of July 2023 in Google Scholar and PubMed/Medline, Scopus, and Web of Science. Twelve studies were able to include our study. Quality assessment of studies was done by Appraisal tool for Cross-Sectional Studies. The most of the included studies were conducted as allo-HSCT. Infections such as respiratory infection, urinary infection and bacteremia have occurred. The rate of prevalence with P. aeruginosa has varied between 3 and 100%. The average age of the participants was between 1 and 74 years. The rate of prevalence of P. aeruginosa resistant to several drugs has been reported to be variable, ranging from 20 to 100%. The highest antibiotic resistance was reported against cefotetan (100%), and the lowest was related to tobramycin (1.8%) followed by amikacin, levofloxacin and ciprofloxacin with the prevalence of 16.6%. Our findings showed a high prevalence and antibiotic resistance rate of P. aeruginosa in Hematopoietic stem cell transplantation. Therefore, more serious health measures should be taken in patients after transplantation.
Topics: Humans; Anti-Bacterial Agents; Cross-Sectional Studies; Drug Resistance, Multiple, Bacterial; Hematopoietic Stem Cell Transplantation; Prevalence; Pseudomonas aeruginosa; Pseudomonas Infections
PubMed: 37769854
DOI: 10.1016/j.micpath.2023.106368 -
FEMS Microbiology Ecology Oct 2023Important bacterial pathogens such as Pseudomonas aeruginosa produce several exoproducts such as siderophores, degradative enzymes, biosurfactants, and... (Review)
Review
Important bacterial pathogens such as Pseudomonas aeruginosa produce several exoproducts such as siderophores, degradative enzymes, biosurfactants, and exopolysaccharides that are used extracellularly, benefiting all members of the population, hence being public goods. Since the production of public goods is a cooperative trait, it is in principle susceptible to cheating by individuals in the population who do not invest in their production, but use their benefits, hence increasing their fitness at the expense of the cooperators' fitness. Among the most studied virulence factors susceptible to cheating are siderophores and exoproteases, with several studies in vitro and some in animal infection models. In addition to these two well-known examples, cheating with other virulence factors such as exopolysaccharides, biosurfactants, eDNA production, secretion systems, and biofilm formation has also been studied. In this review, we discuss the evidence of the susceptibility of each of those virulence factors to cheating, as well as the mechanisms that counteract this behavior and the possible consequences for bacterial virulence.
Topics: Humans; Siderophores; Virulence Factors; Pseudomonas aeruginosa; Biofilms; Quorum Sensing
PubMed: 37827541
DOI: 10.1093/femsec/fiad128 -
BioTechniques Nov 2023Skin and soft tissue infections caused by are common acquired diseases in postpartum care. Many methods have been developed in recent years for detecting , but they are...
Skin and soft tissue infections caused by are common acquired diseases in postpartum care. Many methods have been developed in recent years for detecting , but they are criticized for the drawbacks of labor-intensiveness, complicated operation and high cost. Here, a simple, sensitive and colorimetric assay for detection is described. The approach displays a green color for positive samples and colorless for target-free samples. The approach exhibits a wide detection range and a low limit of detection of 45 CFU/ml. Thus, the developed ligation-initiated multiple-signal amplification method may be used for on-site testing of pathogenic bacteria and assist in the early diagnosis of postpartum care skin infections.
Topics: Humans; Colorimetry; Pseudomonas Infections; Pseudomonas aeruginosa
PubMed: 37881830
DOI: 10.2144/btn-2023-0030 -
MBio Oct 2023Chemotaxis of motile bacteria has multiple physiological functions. It enables bacteria to locate optimal ecological niches, mediates collective behaviors, and can play...
Chemotaxis of motile bacteria has multiple physiological functions. It enables bacteria to locate optimal ecological niches, mediates collective behaviors, and can play an important role in infection. These multiple functions largely depend on ligand specificities of chemoreceptors, and the number and identities of chemoreceptors show high diversity between organisms. Similar diversity is observed for the spectra of chemoeffectors, which include not only chemicals of high metabolic value but also bacterial, plant, and animal signaling molecules. However, the systematic identification of chemoeffectors and their mapping to specific chemoreceptors remains a challenge. Here, we combined several and approaches to establish a systematic screening strategy for the identification of receptor ligands and we applied it to identify a number of new physiologically relevant chemoeffectors for the important opportunistic human pathogen . This strategy can be equally applicable to map specificities of sensory domains from a wide variety of receptor types and bacteria.
Topics: Animals; Humans; Pseudomonas aeruginosa; Bacterial Proteins; Chemoreceptor Cells; Chemotaxis; Bacteria
PubMed: 37791891
DOI: 10.1128/mbio.02099-23 -
Journal of Bacteriology Aug 2023Pseudomonas aeruginosa is an opportunistic pathogen heavily implicated in chronic diseases. Immunocompromised patients that become infected with P. aeruginosa usually... (Review)
Review
Pseudomonas aeruginosa is an opportunistic pathogen heavily implicated in chronic diseases. Immunocompromised patients that become infected with P. aeruginosa usually are afflicted with a lifelong chronic infection, leading to worsened patient outcomes. The complement system is an integral piece of the first line of defense against invading microorganisms. Gram-negative bacteria are thought to be generally susceptible to attack from complement; however, P. aeruginosa can be an exception, with certain strains being serum resistant. Various molecular mechanisms have been described that confer P. aeruginosa unique resistance to numerous aspects of the complement response. In this review, we summarize the current published literature regarding the interactions of P. aeruginosa and complement, as well as the mechanisms used by P. aeruginosa to exploit various complement deficiencies and the strategies used to disrupt or hijack normal complement activities.
Topics: Humans; Pseudomonas aeruginosa; Pseudomonas Infections; Complement System Proteins
PubMed: 37436150
DOI: 10.1128/jb.00018-23 -
Frontiers in Cellular and Infection... 2023() is an important bacterial pathogen involved in a wide range of infections and antimicrobial resistance. Rapid and reliable diagnostic methods are of vital important...
() is an important bacterial pathogen involved in a wide range of infections and antimicrobial resistance. Rapid and reliable diagnostic methods are of vital important for early identification, treatment, and stop of infections. In this study, we developed a simple, rapid, sensitive, and specific detection platform for infection diagnosis. The method integrated recombinase polymerase amplification (RPA) technique with clustered regularly interspaced short palindromic repeat (CRISPR)-CRISPR-associated protein 12a (Cas12a) biosensing system and was termed -CRISPR-RPA assay. The -CRISPR-RPA assay was subject to optimization of reaction conditions and evaluation of sensitivity, specificity, and clinical feasibility with the serial dilutions of genomic DNA, the non strains, and the clinical samples. As a result, the -CRISPR-RPA assay was able to complete detection within half an hour, including RPA reaction at 42°C for 20 min and CRISPR-Cas12a detection at 37°C for 10 min. The diagnostic method exhibited high sensitivity (60 fg per reaction, ~8 copies) and specificity (100%). The results of the clinical samples by -CRISPR-RPA assay were consistent to that of the initial result by microfluidic chip method. These data demonstrated that the newly developed -CRISPR-RPA assay was reliable for detection. In summary, the -CRISPR-RPA assay is a promising tool to early and rapid diagnose infection and stop its wide spread especially in the hospital settings.
Topics: Recombinases; Pseudomonas aeruginosa; CRISPR-Cas Systems; Nucleotidyltransferases; Hospitals
PubMed: 37637458
DOI: 10.3389/fcimb.2023.1239269 -
Virus Research Oct 2023Pseudomonas aeruginosa is a clinically common conditionally pathogenic bacterium, and the abuse of antibiotics has exacerbated its drug resistance in recent years. This...
Pseudomonas aeruginosa is a clinically common conditionally pathogenic bacterium, and the abuse of antibiotics has exacerbated its drug resistance in recent years. This has resulted in extensive reports about the usage of Pseudomonas aeruginosa phage as a novel antibacterial drug. In this study, we isolated a novel phage HZ2201 with a broad lytic spectrum. The lytic rate of this phage against Pseudomonas aeruginosa reached 78.38% (29/37), including 25 multi-drug- and carbapenem-resistant Pseudomonas aeruginosa strains. Transmission electron microscopy revealed that phage HZ2201 belongs to the class Caudoviricetes. Biological characterization showed that phage HZ2201 had an latent period of 40 min, a lytic period of 20 min, and a burst size of 440 PFU/cell, with improved tolerance to temperature and pH. Considering genomic analysis, the HZ2201 genome was a circular double-stranded DNA with a size of 45,431 bp and a guanine-cytosine (G + C) content of 52.16%, and contained 3 tRNAs. 27 of the 74 open reading frames (ORFs) annotated by the Rapid Annotation using Subsystem Technology (RAST) tool could be matched to the genomes of known functions, and no genes related to virulence and antibiotic resistance were found. The phylogenetic tree suggests that phage HZ2201 is highly related to the phage ZCPS1 and PaP3, and ORF57 and ORF17 are predicted to encode a holin and an endolysin, respectively. Cell lysis by HZ2201 proceeds through the holin-endolysin system, suggesting that it is a novel phage. Additionally, we demonstrated that phage HZ2201 has a high inhibitory capacity against Pseudomonas aeruginosa biofilms. The results of our study suggest that phage HZ2201 is a novel potential antimicrobial agent for treating drug-resistant Pseudomonas aeruginosa infection.
Topics: Bacteriophages; Pseudomonas aeruginosa; Phylogeny; Pseudomonas Phages; Genomics; Genome, Viral; Biofilms
PubMed: 37532140
DOI: 10.1016/j.virusres.2023.199184 -
International Journal of Molecular... Oct 2023PAO1, as an experimental model for Gram-negative bacteria, harbors two NADP-dependent isocitrate dehydrogenases (NADP-IDHs) that were evolved from its ancient...
PAO1, as an experimental model for Gram-negative bacteria, harbors two NADP-dependent isocitrate dehydrogenases (NADP-IDHs) that were evolved from its ancient counterpart NAD-IDHs. For a better understanding of PaIDH1 and PaIDH2, we cloned the genes, overexpressed them in and purified them to homogeneity. PaIDH1 displayed higher affinity to NADP and isocitrate, with lower Km values when compared to PaIDH2. Moreover, PaIDH1 possessed higher temperature tolerance (50 °C) and wider pH range tolerance (7.2-8.5) and could be phosphorylated. After treatment with the bifunctional PaIDH kinase/phosphatase (PaIDH K/P), PaIDH1 lost 80% of its enzymatic activity in one hour due to the phosphorylation of Ser115. Small-molecule compounds like glyoxylic acid and oxaloacetate can effectively inhibit the activity of PaIDHs. The mutant PaIDH1-D346I347A353K393 exhibited enhanced affinity for NAD while it lost activity towards NADP, and the Km value (7770.67 μM) of the mutant PaIDH2-L589 I600 for NADP was higher than that observed for NAD (5824.33 μM), indicating a shift in coenzyme specificity from NADP to NAD for both PaIDHs. The experiments demonstrated that the mutation did not alter the oligomeric state of either protein. This study provides a foundation for the elucidation of the evolution and function of two NADP-IDHs in the pathogenic bacterium .
Topics: Coenzymes; Pseudomonas aeruginosa; NADP; NAD; Amino Acid Sequence; Isocitrate Dehydrogenase; Isocitrates; Kinetics
PubMed: 37834433
DOI: 10.3390/ijms241914985 -
Applied and Environmental Microbiology Jun 2024Solid surfaces submerged in liquid in natural environments alter bacterial swimming behavior and serve as platforms for bacteria to form biofilms. In the initial stage...
UNLABELLED
Solid surfaces submerged in liquid in natural environments alter bacterial swimming behavior and serve as platforms for bacteria to form biofilms. In the initial stage of biofilm formation, bacteria detect surfaces and increase the intracellular level of the second messenger c-di-GMP, leading to a reduction in swimming speed. The impact of this speed reduction on bacterial surface swimming remains unclear. In this study, we utilized advanced microscopy techniques to examine the effect of swimming speed on bacterial surface swimming behavior. We found that a decrease in swimming speed reduces the cell-surface distance and prolongs the surface trapping time. Both these effects would enhance bacterial surface sensing and increase the likelihood of cells adhering to the surface, thereby promoting biofilm formation. We also examined the surface-escaping behavior of wild-type and , noting distinct surface-escaping mechanisms between the two bacterial species.
IMPORTANCE
In the early phase of biofilm formation, bacteria identify surfaces and increase the intracellular level of the second messenger c-di-GMP, resulting in a decrease in swimming speed. Here, we utilized advanced microscopy techniques to investigate the impact of swimming speed on bacterial surface swimming, focusing on and . We found that an increase in swimming speed led to an increase in the radius of curvature and a decrease in surface detention time. These effects were explained through hydrodynamic modeling as a result of an increase in the cell-surface distance with increasing swimming speed. We also observed distinct surface-escaping mechanisms between the two bacterial species. Our study suggests that a decrease in swimming speed could enhance the likelihood of cells adhering to the surface, promoting biofilm formation. This sheds light on the role of reduced swimming speed in the transition from motile to sedentary bacterial lifestyles.
Topics: Escherichia coli; Biofilms; Pseudomonas aeruginosa; Cyclic GMP; Bacterial Adhesion
PubMed: 38717126
DOI: 10.1128/aem.00508-24 -
Expert Opinion on Therapeutic Patents Jun 2024(PA) is a Gram-negative bacterium that can cause a wide range of severe infections in immunocompromised patients. The most difficult challenge is due to its ability to... (Review)
Review
INTRODUCTION
(PA) is a Gram-negative bacterium that can cause a wide range of severe infections in immunocompromised patients. The most difficult challenge is due to its ability to rapidly develop multi drug-resistance. New strategies are urgently required to improve the outcome of patients with PA infections. The present patent review highlights the new molecules acting on different targets involved in the antibiotic resistance.
AREA COVERED
This review offers an insight into new potential PA treatment disclosed in patent literature. From a broad search of documents claiming new PA inhibitors, we selected and summarized molecules that showed in vitro and in vivo activity against PA spp. in the period 2020 and 2023. We collected the search results basing on the targets explored.
EXPERT OPINION
This review examined the main patented compounds published in the last three years, with regard to the structural novelty and the identification of innovative targets. The main areas of antibiotic resistance have been explored. The compounds are structurally unrelated to earlier antibiotics, characterized by a medium-high molecular weight and the presence of heterocycle rings. Peptides and antibodies have also been reported as potential alternatives to chemical treatment, hereby expanding the therapeutic possibilities in this field.
Topics: Pseudomonas aeruginosa; Patents as Topic; Humans; Pseudomonas Infections; Anti-Bacterial Agents; Animals; Drug Resistance, Multiple, Bacterial; Drug Development; Immunocompromised Host; Drug Design
PubMed: 38683024
DOI: 10.1080/13543776.2024.2348602