scholarly journals Global reprogramming of virulence and antibiotic resistance in Pseudomonas aeruginosa by a single nucleotide polymorphism in the elongation factor-encoding gene, fusA1

2019 ◽  
Author(s):  
Eve A. Maunders ◽  
Rory C. Triniman ◽  
Taufiq Rahman ◽  
Martin Welch
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antibiotic Resistance ◽  
Large Scale ◽  
Efflux Pump ◽  
Elongation Factor ◽  
Virulence Gene ◽  
Mutant Gene ◽  
Opportunistic Pathogen ◽  
Aminoglycoside Resistance ◽  
Virulence Gene Expression

AbstractPseudomonas aeruginosa is a common opportunistic pathogen. The organism displays elevated intrinsic antibiotic resistance and can cause life-threatening infections. The gene encoding an elongation factor, FusA1, is frequently mutated in clinical isolates of P. aeruginosa from patients with cystic fibrosis (CF). Recent work has shown that fusA1 mutants often display elevated aminoglycoside resistance due to increased expression of the aminoglycoside efflux pump, MexXY. In the current work, we isolated a spontaneous gentamicin-resistant fusA1 mutant (FusA1P443L) in which mexXY expression was increased. Through a combination of proteomic and transcriptomic analyses, we found that the fusA1 mutant also exhibited large-scale but discrete changes in the expression of key pathogenicity-associated genes. Most notably, the fusA1 mutant displayed greatly increased expression of the Type III Secretion system (T3SS), widely considered to be the most potent virulence factor in the P. aeruginosa arsenal, and also elevated expression of the Type VI Secretion (T6S) machinery. This was unexpected because expression of the T3SS is usually reciprocally coordinated with T6S system expression. The fusA1 mutant also displayed elevated exopolysaccharide production, dysregulated siderophore production, elevated ribosomal protein synthesis, and transcriptomic signatures indicative of translational stress. Each of these phenotypes (and almost all of the transcriptomic and proteomic changes associated with the fusA1 mutation) were restored to levels comparable to that in the PAO1-derived progenitor strain by expression of the wild-type fusA1 gene in trans, indicating that the mutant gene is recessive. Our data show that in addition to elevating antibiotic resistance through mexXY expression (although we also identify additional contributory resistance mechanisms), mutations in fusA1 can lead to highly-selective dysregulation of virulence gene expression.

scholarly journals Global reprogramming of virulence and antibiotic resistance in Pseudomonas aeruginosa by a single nucleotide polymorphism in elongation factor, fusA1

2020 ◽  
Vol 295 (48) ◽  
pp. 16411-16426
Author(s):  
Eve A. Maunders ◽  
Rory C. Triniman ◽  
Joshua Western ◽  
Taufiq Rahman ◽  
Martin Welch
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antibiotic Resistance ◽  
Efflux Pump ◽  
Elongation Factor ◽  
Virulence Gene ◽  
Mutant Gene ◽  
Opportunistic Pathogen ◽  
Secretion System ◽  
Aminoglycoside Resistance ◽  
Virulence Gene Expression

Clinical isolates of the opportunistic pathogen Pseudomonas aeruginosa from patients with cystic fibrosis (CF) frequently contain mutations in the gene encoding an elongation factor, FusA1. Recent work has shown that fusA1 mutants often display elevated aminoglycoside resistance due to increased expression of the efflux pump, MexXY. However, we wondered whether these mutants might also be affected in other virulence-associated phenotypes. Here, we isolated a spontaneous gentamicin-resistant fusA1 mutant (FusA1P443L) in which mexXY expression was increased. Proteomic and transcriptomic analyses revealed that the fusA1 mutant also exhibited discrete changes in the expression of key pathogenicity-associated genes. Most notably, the fusA1 mutant displayed greatly increased expression of the Type III secretion system (T3SS), widely considered to be the most potent virulence factor in the P. aeruginosa arsenal, and also elevated expression of the Type VI (T6) secretion machinery. This was unexpected because expression of the T3SS is usually reciprocally coordinated with T6 secretion system expression. The fusA1 mutant also displayed elevated exopolysaccharide production, dysregulated siderophore production, elevated ribosome synthesis, and transcriptomic signatures indicative of translational stress. Each of these phenotypes (and almost all of the transcriptomic and proteomic changes associated with the fusA1 mutation) were restored to levels comparable with that in the progenitor strain by expression of the WT fusA1 gene in trans, indicating that the mutant gene is recessive. Our data show that in addition to elevating antibiotic resistance through mexXY expression (and also additional contributory resistance mechanisms), mutations in fusA1 can lead to highly selective dysregulation of virulence gene expression.

scholarly journals Identification of Synthetic Inducers and Inhibitors of the Quorum-Sensing Regulator LasR in Pseudomonas aeruginosa by High-Throughput Screening

2010 ◽  
Vol 76 (24) ◽  
pp. 8255-8258 ◽  
Author(s):  
Bradley R. Borlee ◽  
Grant D. Geske ◽  
Helen E. Blackwell ◽  
Jo Handelsman
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Quorum Sensing ◽  
High Throughput ◽  
High Throughput Screening ◽  
Virulence Gene ◽  
Opportunistic Pathogen ◽  
Homoserine Lactone ◽  
Virulence Gene Expression ◽  
Significant Interest ◽  
Sensor Strain

ABSTRACT We report the screening of 16,000 synthetic compounds for induction and inhibition of quorum sensing in a Pseudomonas putida N-acylated l-homoserine lactone (AHL) sensor strain engineered with the LasR transcriptional activator. LasR controls virulence gene expression in the opportunistic pathogen Pseudomonas aeruginosa and is of significant interest as a therapeutic target. Nine compounds that inhibit and 14 compounds that induce LasR activity were identified in our high-throughput screen.

scholarly journals Mutations in Gene fusA1 as a Novel Mechanism of Aminoglycoside Resistance in Clinical Strains of Pseudomonas aeruginosa

2017 ◽  
Vol 62 (2) ◽  
Author(s):  
Arnaud Bolard ◽  
Patrick Plésiat ◽  
Katy Jeannot
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Amino Acid ◽  
Efflux Pump ◽  
Elongation Factor ◽  
Genetic Alterations ◽  
Single Amino Acid ◽  
Multidrug Efflux Pump ◽  
Aminoglycoside Resistance ◽  
Content Type ◽  
Clinical Strains

ABSTRACT Resistance of clinical strains of Pseudomonas aeruginosa to aminoglycosides can result from production of transferable aminoglycoside-modifying enzymes, of 16S rRNA methylases, and/or mutational derepression of intrinsic multidrug efflux pump MexXY(OprM). We report here the characterization of a new type of mutant that is 4- to 8-fold more resistant to 2-deoxystreptamine derivatives (e.g., gentamicin, amikacin, and tobramycin) than the wild-type strain PAO1. The genetic alterations of three in vitro mutants were mapped on fusA1 and found to result in single amino acid substitutions in domains II, III, and V of elongation factor G (EF-G1A), a key component of translational machinery. Transfer of the mutated fusA1 alleles into PAO1 reproduced the resistance phenotype. Interestingly, fusA1 mutants with other amino acid changes in domains G, IV, and V of EF-G1A were identified among clinical strains with decreased susceptibility to aminoglycosides. Allelic-exchange experiments confirmed the relevance of these latter mutations and of three other previously reported alterations located in domains G and IV. Pump MexXY(OprM) partly contributed to the resistance conferred by the mutated EF-G1A variants and had additive effects on aminoglycoside MICs when mutationally upregulated. Altogether, our data demonstrate that cystic fibrosis (CF) and non-CF strains of P. aeruginosa can acquire a therapeutically significant resistance to important aminoglycosides via a new mechanism involving mutations in elongation factor EF-G1A.

scholarly journals Carbapenem-Resistant Pseudomonas aeruginosa Strains-Distribution of the Essential Enzymatic Virulence Factors Genes

Antibiotics ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 8
Author(s):  
Tomasz Bogiel ◽  
Małgorzata Prażyńska ◽  
Joanna Kwiecińska-Piróg ◽  
Agnieszka Mikucka ◽  
Eugenia Gospodarek-Komkowska
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Alkaline Protease ◽  
Virulence Genes ◽  
Virulence Gene ◽  
Hospital Environment ◽  
Gene Encoding ◽  
Virulence Gene Expression ◽  
Carbapenem Resistant ◽  
Antimicrobial Resistance Genes ◽  
The Difference

Pseudomonas aeruginosa is one of the most commonly isolated bacteria from clinical specimens, with increasing isolation frequency in nosocomial infections. Herein, we investigated whether antimicrobial-resistant P. aeruginosa strains, e.g., metallo-beta-lactamase (MBL)-producing isolates, may possess a reduced number of virulence genes, resulting from appropriate genome management to adapt to a changing hospital environment. Hospital conditions, such as selective pressure, may lead to the replacement of virulence genes by antimicrobial resistance genes that are crucial to survive under current conditions. The study aimed to compare, using PCR, the frequency of the chosen enzymatic virulence factor genes (alkaline protease-aprA, elastase B-lasB, neuraminidases-nan1 and nan2, and both variants of phospholipase C-plcH and plcN) to MBL distribution among 107 non-duplicated carbapenem-resistant P. aeruginosa isolates. The gene encoding alkaline protease was noted with the highest frequency (100%), while the neuraminidase-1 gene was observed in 37.4% of the examined strains. The difference in lasB and nan1 prevalence amongst the MBL-positive and MBL-negative strains, was statistically significant. Although P. aeruginosa virulence is generally more likely determined by the complex regulation of the virulence gene expression, herein, we found differences in the prevalence of various virulence genes in MBL-producers.

scholarly journals Growing Menace of Antibacterial Resistance in Clinical Isolates ofPseudomonas aeruginosain Nepal: An Insight of Beta-Lactamase Production

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Shamshul Ansari ◽  
Rabindra Dhital ◽  
Sony Shrestha ◽  
Sangita Thapa ◽  
Ram Puri ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antibiotic Resistance ◽  
Opportunistic Pathogen ◽  
Resistance Rate ◽  
Diffusion Method ◽  
Beta Lactamase ◽  
Beta Lactam ◽  
Beta Lactam Antibiotics ◽  
Microbiological Methods ◽  
Immunosuppressed Patients

Introduction. Pseudomonas aeruginosais the most frequently isolated organism as it acts as the opportunistic pathogen and can cause infections in immunosuppressed patients. The production of different types of beta-lactamases renders this organism resistant to many commonly used antimicrobials. Therefore, the aim of this study was to document the antibiotic resistance rate inPseudomonas aeruginosaisolated from different clinical specimens.Methods. Pseudomonas aeruginosarecovered was identified by standard microbiological methods. Antibiotic susceptibility testing was performed by modified Kirby-Bauer disc diffusion method following Clinical and Laboratory Standard Institute (CLSI) guidelines and all the suspected isolates were tested for the production of ESBLs, MBLs, and AmpC.Results.Out of total (178) isolates, 83.1% were recovered from the inpatient department (IPD). Majority of the isolates mediated resistance towards the beta-lactam antibiotics, while nearly half of the isolates were resistant to ciprofloxacin. Most of the aminoglycosides used showed resistance rate up to 75% but amikacin proved to be better option. No resistance to polymyxin was observed. ESBLs, MBLs, and AmpC mediated resistance was seen in 33.1%, 30.9%, and 15.7% isolates, respectively.Conclusions. Antibiotic resistance rate and beta-lactamase mediated resistance were high. Thus, regular surveillance of drug resistance is of utmost importance.

scholarly journals The Genomic Basis of Rapid Adaptation to Antibiotic Combination Therapy in Pseudomonas aeruginosa

2020 ◽  
Author(s):  
Camilo Barbosa ◽  
Niels Mahrt ◽  
Julia Bunk ◽  
Matthias Graßer ◽  
Philip Rosenstiel ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Combination Therapy ◽  
Bacterial Resistance ◽  
Efflux Pump ◽  
Regulatory Gene ◽  
Opportunistic Pathogen ◽  
Regulatory Function ◽  
Central Target ◽  
Resistance Evolution ◽  
Intergenic Regions

Abstract Combination therapy is a common antibiotic treatment strategy that aims at minimizing the risk of resistance evolution in several infectious diseases. Nonetheless, evidence supporting its efficacy against the nosocomial opportunistic pathogen Pseudomonas aeruginosa remains elusive. Identification of the possible evolutionary paths to resistance in multidrug environments can help to explain treatment outcome. For this purpose, we here performed whole-genome sequencing of 127 previously evolved populations of P. aeruginosa adapted to sublethal doses of distinct antibiotic combinations and corresponding single-drug treatments, and experimentally characterized several of the identified variants. We found that alterations in the regulation of efflux pumps are the most favored mechanism of resistance, regardless of the environment. Unexpectedly, we repeatedly identified intergenic variants in the adapted populations, often with no additional mutations and usually associated with genes involved in efflux pump expression, possibly indicating a regulatory function of the intergenic regions. The experimental analysis of these variants demonstrated that the intergenic changes caused similar increases in resistance against single and multidrug treatments as those seen for efflux regulatory gene mutants. Surprisingly, we could find no substantial fitness costs for a majority of these variants, most likely enhancing their competitiveness toward sensitive cells, even in antibiotic-free environments. We conclude that the regulation of efflux is a central target of antibiotic-mediated selection in P. aeruginosa and that, importantly, changes in intergenic regions may represent a usually neglected alternative process underlying bacterial resistance evolution, which clearly deserves further attention in the future.

scholarly journals Molecular Characteristics of Streptococcus pyogenes Isolated From Chinese Children With Different Diseases

2021 ◽  
Vol 12 ◽  
Author(s):  
Dingle Yu ◽  
Yunmei Liang ◽  
Qinghua Lu ◽  
Qing Meng ◽  
Wenjian Wang ◽  
...  
Keyword(s):  
Gene Expression ◽  
Antibiotic Resistance ◽  
Streptococcus Pyogenes ◽  
Wide Spectrum ◽  
Expression Patterns ◽  
Virulence Gene ◽  
High Rate ◽  
Molecular Characteristics ◽  
Virulence Gene Expression ◽  
Obstructive Sleep

Streptococcus pyogenes is a bacterial pathogen that causes a wide spectrum of clinical diseases exclusively in humans. The distribution of emm type, antibiotic resistance and virulence gene expression for S. pyogenes varies temporally and geographically, resulting in distinct disease spectra. In this study, we analyzed antibiotic resistance and resistance gene expression patterns among S. pyogenes isolates from pediatric patients in China and investigated the relationship between virulence gene expression, emm type, and disease categories. Forty-two representative emm1.0 and emm12.0 strains (n = 20 and n = 22, respectively) isolated from patients with scarlet fever or obstructive sleep apnea-hypopnea syndrome were subjected to whole-genome sequencing and phylogenetic analysis. These strains were further analyzed for susceptibility to vancomycin. We found a high rate and degree of resistance to macrolides and tetracycline in these strains, which mainly expressed ermB and tetM. The disease category correlated with emm type but not superantigens. The distribution of vanuG and virulence genes were associated with emm type. Previously reported important prophages, such as φHKU16.vir, φHKU488.vir, Φ5005.1, Φ5005.2, and Φ5005.3 encoding streptococcal toxin, and integrative conjugative elements (ICEs) such as ICE-emm12 and ICE-HKU397 encoding macrolide and tetracycline resistance were found present amongst emm1 or emm12 clones from Shenzhen, China.

scholarly journals Association among biofilm formation, virulence gene expression, and antibiotic resistance in Proteus mirabilis isolates from diarrhetic animals in northeast China

2020 ◽  
Author(s):  
Yadong Sun ◽  
Shanshan Wen ◽  
Lili Zhao ◽  
Qiqi Xia ◽  
Yue Pan ◽  
...  
Keyword(s):  
Gene Expression ◽  
Antibiotic Resistance ◽  
Biofilm Formation ◽  
Northeast China ◽  
Virulence Gene ◽  
Drug Susceptibility ◽  
Multidrug Resistant ◽  
Virulence Gene Expression ◽  
Biofilm Production ◽  
High Level

Abstract Background The aim of this study was to investigate the association among biofilm formation, virulence gene expression, and antibiotic resistance in P. mirabilis isolates collected from diarrhetic animals (n = 176) in northeast China between September 2014 and October 2016. Results Approximately 92.05% of the isolates were biofilm producers, whereas 7.95% of the isolates were non-producers. The prevalence of virulence genes in biofilm producers was significantly higher than that in non-producers. Biofilm production was significantly associated with the expression of ureC , zapA , rsmA , hmpA , mrpA , atfA , and pmfA ( P < 0.05). Drug susceptibility tests revealed that approximately 76.7% of the isolates were multidrug-resistant (MDR) and extensively drug-resistant (XDR). Biofilm production was significantly associated with resistance to doxycycline, tetracycline, sulfamethoxazole, kanamycin, and cephalothin ( P < 0.05). Although the pathogenicity of the biofilm producers was stronger than that of the non-producers, the biofilm-forming ability of the isolates was not significantly associated with morbidity and mortality in mice ( P > 0.05). Conclusion Our findings suggested that a high level of multidrug resistance in diarrhetic animals infected with P. mirabilis in northeast China.The results of this study indicated that the positive rates of the genes expressed by biofilm-producing P. mirabilis isolates were significantly higher than those expressed by non-producing isolates.

Sign in / Sign up

Export Citation Format

Share Document