scholarly journals Identification of CtpL as a Chromosomally Encoded Chemoreceptor for 4-Chloroaniline and Catechol in Pseudomonas aeruginosa PAO1

2013 ◽  
Vol 79 (23) ◽  
pp. 7241-7248 ◽  
Author(s):  
Alisa S. Vangnai ◽  
Kazuki Takeuchi ◽  
Shota Oku ◽  
Naoya Kataoka ◽  
Tisana Nitisakulkan ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Bacterial Chemotaxis ◽  
Transformation Product ◽  
Phenotypic Characterization ◽  
Aromatic Pollutants ◽  
Content Type ◽  
Environmental Bacterium ◽  
Dead End ◽  
Low Concentrations

ABSTRACTBacterial chemotaxis influences the ability of bacteria to survive and thrive in most environments, including polluted ones. Despite numerous reports of the phenotypic characterization of chemotactic bacteria, only a few molecular details of chemoreceptors for aromatic pollutants have been described. In this study, the molecular basis of chemotaxis toward an environmentally toxic chlorinated aromatic pollutant, 4-chloroaniline (4CA), was evaluated. Among the threePseudomonasspp. tested,Pseudomonas aeruginosaPAO1 exhibited positive chemotaxis both to the nonmetabolizable 4CA, where 4-chloroacetanilide was formed as a dead-end transformation product, and to the metabolizable catechol. Molecular analysis of all 26 mutants with a disrupted methyl-accepting chemotaxis gene revealed that CtpL, a chromosomally encoded chemoreceptor, was responsible for the positive chemotactic response toward 4CA. Since CtpL has previously been described to be a major chemoreceptor for inorganic phosphate at low concentrations in PAO1, this report describes a fortuitous ability of CtpL to function toward aromatic pollutants. In addition, its regulation not only was dependent on the presence of the chemoattractant inducer but also was regulated by conditions of phosphate starvation. These results expand the range of known chemotactic transducers and their function in the environmental bacterium PAO1.

Genotypic and phenotypic characterization of Pseudomonas aeruginosa isolates from urinary tract infections

2011 ◽  
Vol 301 (4) ◽  
pp. 282-292 ◽  
Author(s):  
Petra Tielen ◽  
Maike Narten ◽  
Nathalie Rosin ◽  
Ilona Biegler ◽  
Isam Haddad ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Urinary Tract ◽  
Urinary Tract Infections ◽  
Phenotypic Characterization ◽  
Tract Infections

scholarly journals Genotypic and Phenotypic Characterization of Antimicrobial Resistance in Neisseria gonorrhoeae: a Cross-Sectional Study of Isolates Recovered from Routine Urine Cultures in a High-Incidence Setting

mSphere ◽  
2019 ◽  
Vol 4 (4) ◽  
Author(s):  
Adam L. Bailey ◽  
Robert F. Potter ◽  
Meghan A. Wallace ◽  
Caitlin Johnson ◽  
Gautam Dantas ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Antimicrobial Resistance ◽  
Neisseria Gonorrhoeae ◽  
Susceptibility Testing ◽  
Clinical Laboratory ◽  
Phenotypic Characterization ◽  
First Line ◽  
Content Type ◽  
Gradient Diffusion

ABSTRACT The objectives of this study were to perform genomic and phenotypic characterization of antimicrobial resistance in Neisseria gonorrhoeae isolates recovered from urine samples from patients in St. Louis, MO, USA. Sixty-four clinical isolates were banked over a 2-year period and subjected to antimicrobial susceptibility testing (AST) by Kirby-Bauer disk diffusion (penicillin, tetracycline, cefuroxime, and ciprofloxacin) and gradient diffusion (tetracycline, doxycycline, azithromycin, ceftriaxone, cefixime, ciprofloxacin, gemifloxacin, and delafloxacin). The medical records for the patients were evaluated to determine the demographics, location, and prescribed treatment regimen. Isolate draft genomes were assembled from Illumina shotgun sequencing data, and resistance determinants were identified by ResFinder and PointFinder. Of the 64 isolates, 97% were nonsusceptible to penicillin, with resistant isolates all containing the blaTEM-1b gene; 78 and 81% of isolates were nonsusceptible to tetracycline and doxycycline, respectively, with resistant isolates all containing the tet(M) gene. One isolate was classified as non-wild-type to azithromycin, and all isolates were susceptible to ceftriaxone; 89% of patients received this combination of drugs as first-line therapy. Six percent of isolates were resistant to ciprofloxacin, with most resistant isolates containing multiple gyrA and parC mutations. Correlation between disk and gradient diffusion AST devices was high for tetracycline and ciprofloxacin (R2 > 99% for both). The rates of N. gonorrhoeae antibiotic resistance in St. Louis are comparable to current rates reported nationally, except ciprofloxacin resistance was less common in our cohort. Strong associations between specific genetic markers and phenotypic susceptibility testing hold promise for the utility of genotype-based diagnostic assays to guide directed antibiotic therapy. IMPORTANCE Neisseria gonorrhoeae causes the sexually transmitted infection gonorrhea, which is most commonly diagnosed using a DNA-based detection method that does not require growth and isolation of N. gonorrhoeae in the laboratory. This is problematic because the rates of antibiotic resistance in N. gonorrhoeae are increasing, but without isolating the organism in the clinical laboratory, antibiotic susceptibility testing cannot be performed on strains recovered from clinical specimens. We observed an increase in the frequency of urine cultures growing N. gonorrhoeae after we implemented a total laboratory automation system for culture in our clinical laboratory. Here, we report on the rates of resistance to multiple historically used, first-line, and potential future-use antibiotics for 64 N. gonorrhoeae isolates. We found that the rates of antibiotic resistance in our isolates were comparable to national rates. Additionally, resistance to specific antibiotics correlated closely with the presence of genetic resistance genes, suggesting that DNA-based tests could also be designed to guide antibiotic therapy for treating gonorrhea.

scholarly journals Genotypic and Phenotypic Characterization of Treponema phagedenis from Bovine Digital Dermatitis

2020 ◽  
Vol 8 (10) ◽  
pp. 1520
Author(s):  
Hector M. Espiritu ◽  
Lovelia L. Mamuad ◽  
Su-jeong Jin ◽  
Seon-ho Kim ◽  
Seok-won Kwon ◽  
...  
Keyword(s):  
Slow Growth ◽  
Small Difference ◽  
Phenotypic Characterization ◽  
Average Nucleotide Identity ◽  
Digital Dermatitis ◽  
16S Rrna Analysis ◽  
Single Strain ◽  
Low Concentrations ◽  
Bovine Strain

This study aimed to isolate and characterize Treponema spp. from bovine digital dermatitis (BDD)-infected dairy cattle. Seven isolates were characterized in this study. Isolates exhibited slow growth, and colonies penetrated the agar and exhibited weak β-hemolysis. Round bodies were observed in old and antibiotic-treated cultures. Cells ranged from 9–12 µm in length, 0.2–2.5 µm in width, and were moderately spiraled. The 16S rRNA analysis revealed the isolates as Treponema phagedenis with >99% sequence homology. Isolates had alkaline phosphatase, acid phosphatase, β-galactosidase, N-acetyl-β-glucosaminidase, esterase (C4), esterase lipase (C8), naphthol-AS-BI-phosphohydrolase, and β-glucuronidase activities. Low concentrations of ampicillin, erythromycin, and tetracycline were required to inhibit the growth of isolates. Formic, acetic, and butyric acids were produced, while propionic acid was significantly utilized, indicating its essentiality for treponemal growth. The isolates shared the same characteristics and, therefore, were considered as a single strain. Isolate HNL4 was deposited as a representative isolate (Treponema phagedenis KS1). The average nucleotide identity of strain KS1 showed a small difference with the human strain (99.14%) compared with bovine strain (99.72%). This study was the first to isolate and characterize Treponema phagedenis from BDD in Korea and, hence, it delivered pathogenicity-related insights and provided valuable information that can be used for the management of BDD.

scholarly journals Identification of Novel VEB β-Lactamase Enzymes and Their Impact on Avibactam Inhibition

2016 ◽  
Vol 60 (5) ◽  
pp. 3183-3186 ◽  
Author(s):  
Sushmita D. Lahiri ◽  
Richard A. Alm
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Binding Pocket ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Content Type ◽  
Class A ◽  
Extended Spectrum ◽  
Class C

ABSTRACTCeftazidime-avibactam has activity againstPseudomonas aeruginosaandEnterobacteriaceaeexpressing numerous class A and class C β-lactamases, although the ability to inhibit many minor enzyme variants has not been established. Novel VEB class A β-lactamases were identified during characterization of surveillance isolates. The cloned novel VEB β-lactamases possessed an extended-spectrum β-lactamase phenotype and were inhibited by avibactam in a concentration-dependent manner. The residues that comprised the avibactam binding pocket were either identical or functionally conserved. These data demonstrate that avibactam can inhibit VEB β-lactamases.

scholarly journals Identification of FDA-Approved Drugs as Antivirulence Agents Targeting the pqs Quorum-Sensing System of Pseudomonas aeruginosa

2018 ◽  
Vol 62 (11) ◽  
Author(s):  
Francesca D'Angelo ◽  
Valerio Baldelli ◽  
Nigel Halliday ◽  
Paolo Pantalone ◽  
Fabio Polticelli ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Quorum Sensing ◽  
Biofilm Formation ◽  
Antifungal Drugs ◽  
Phenotypic Characterization ◽  
Resistant Bacteria ◽  
Gram Positive ◽  
Active Inhibitor ◽  
Content Type ◽  
Approved Drugs

ABSTRACT The long-term use of antibiotics has led to the emergence of multidrug-resistant bacteria. A promising strategy to combat bacterial infections aims at hampering their adaptability to the host environment without affecting growth. In this context, the intercellular communication system quorum sensing (QS), which controls virulence factor production and biofilm formation in diverse human pathogens, is considered an ideal target. Here, we describe the identification of new inhibitors of the pqs QS system of the human pathogen Pseudomonas aeruginosa by screening a library of 1,600 U.S. Food and Drug Administration-approved drugs. Phenotypic characterization of ad hoc engineered strains and in silico molecular docking demonstrated that the antifungal drugs clotrimazole and miconazole, as well as an antibacterial compound active against Gram-positive pathogens, clofoctol, inhibit the pqs system, probably by targeting the transcriptional regulator PqsR. The most active inhibitor, clofoctol, specifically inhibited the expression of pqs-controlled virulence traits in P. aeruginosa, such as pyocyanin production, swarming motility, biofilm formation, and expression of genes involved in siderophore production. Moreover, clofoctol protected Galleria mellonella larvae from P. aeruginosa infection and inhibited the pqs QS system in P. aeruginosa isolates from cystic fibrosis patients. Notably, clofoctol is already approved for clinical treatment of pulmonary infections caused by Gram-positive bacterial pathogens; hence, this drug has considerable clinical potential as an antivirulence agent for the treatment of P. aeruginosa lung infections.

Genotype to phenotype: identification of diagnostic vibrio phenotypes using whole genome sequences

2014 ◽  
Vol 64 (Pt_2) ◽  
pp. 357-365 ◽  
Author(s):  
Gilda Rose S. Amaral ◽  
Graciela M. Dias ◽  
Michiyo Wellington-Oguri ◽  
Luciane Chimetto ◽  
Mariana E. Campeão ◽  
...  
Keyword(s):  
Phenotypic Characterization ◽  
Whole Genome ◽  
Genome Sequences ◽  
Diagnostic Features ◽  
Phenotypic Data ◽  
Content Type ◽  
Ecological Relationships ◽  
Phenotypic Information ◽  
Specific Proteins

Vibrios are ubiquitous in the aquatic environment and can be found in association with animal or plant hosts. The range of ecological relationships includes pathogenic and mutualistic associations. To gain a better understanding of the ecology of these microbes, it is important to determine their phenotypic features. However, the traditional phenotypic characterization of vibrios has been expensive, time-consuming and restricted in scope to a limited number of features. In addition, most of the commercial systems applied for phenotypic characterization cannot characterize the broad spectrum of environmental strains. A reliable and possible alternative is to obtain phenotypic information directly from whole genome sequences. The aim of the present study was to evaluate the usefulness of whole genome sequences as a source of phenotypic information. We performed a comparison of the vibrio phenotypes obtained from the literature with the phenotypes obtained from whole genome sequences. We observed a significant correlation between the previously published phenotypic data and the phenotypic data retrieved from whole genome sequences of vibrios. Analysis of 26 vibrio genomes revealed that all genes coding for the specific proteins involved in the metabolic pathways responsible for positive phenotypes of the 14 diagnostic features (Voges–Proskauer reaction, indole production, arginine dihydrolase, ornithine decarboxylase, utilization of myo-inositol, sucrose and l-leucine, and fermentation of d-mannitol, d-sorbitol, l-arabinose, trehalose, cellobiose, d-mannose and d-galactose) were found in the majority of the vibrios genomes. Vibrio species that were negative for a given phenotype revealed the absence of all or several genes involved in the respective biochemical pathways, indicating the utility of this approach to characterize the phenotypes of vibrios. The absence of the global regulation and regulatory proteins in the Vibrio parahaemolyticus genome indicated a non-vibrio phenotype. Whole genome sequences represent an important source for the phenotypic identification of vibrios.

scholarly journals Major Release of 161 Whole-Genome Sequences from the International Pseudomonas Consortium Database

2019 ◽  
Vol 8 (13) ◽  
Author(s):  
Julie Jeukens ◽  
Jean-Guillaume Emond-Rheault ◽  
Luca Freschi ◽  
Irena Kukavica-Ibrulj ◽  
Roger C. Levesque
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Draft Genome ◽  
Opportunistic Pathogen ◽  
Whole Genome ◽  
Genome Sequences ◽  
Content Type ◽  
Environmental Bacterium

Pseudomonas aeruginosa is an environmental bacterium and opportunistic pathogen. Here, we present draft genome sequences for 161 isolates from diverse clinical and environmental sources.

scholarly journals Six novel species of the obligate marine actinobacterium Salinispora, Salinispora cortesiana sp. nov., Salinispora fenicalii sp. nov., Salinispora goodfellowii sp. nov., Salinispora mooreana sp. nov., Salinispora oceanensis sp. nov. and Salinispora vitiensis sp. nov., and emended description of the genus Salinispora

2020 ◽  
Vol 70 (8) ◽  
pp. 4668-4682 ◽  
Author(s):  
Brenda Román-Ponce ◽  
Natalie Millán-Aguiñaga ◽  
Dulce Guillen-Matus ◽  
Alexander B. Chase ◽  
Joape G.M. Ginigini ◽  
...  
Keyword(s):  
Sequence Similarity ◽  
Taxonomic Status ◽  
Phenotypic Characterization ◽  
Comparative Genomic ◽  
Rrna Gene ◽  
Content Type ◽  
Link Type ◽  
Physiological And Biochemical Characteristics ◽  
Genome Phylogeny

Ten representative actinobacterial strains isolated from marine sediments collected worldwide were studied to determine their taxonomic status. The strains were previously identified as members of the genus Salinispora and shared >99 % 16S rRNA gene sequence similarity to the three currently recognized Salinispora species. Comparative genomic analyses resulted in the delineation of six new species based on average nucleotide identity and digital DNA–DNA hybridization values below 95 and 70 %, respectively. The species status of the six new groups was supported by a core-genome phylogeny reconstructed from 2106 orthologs detected in 118 publicly available Salinispora genomes. Chemotaxonomic and physiological studies were used to complete the phenotypic characterization of the strains. The fatty acid profiles contained the major components iso-C16 : 0, C15 : 0, iso-17 : 0 and anteiso C17 : 0. Galactose and xylose were common in all whole-sugar patterns but differences were found between the six groups of strains. Polar lipid compositions were also unique for each species. Distinguishable physiological and biochemical characteristics were also recorded. The names proposed are Salinispora cortesiana sp. nov., CNY-202T (=DSM 108615T=CECT 9739T); Salinispora fenicalii sp. nov., CNT-569T (=DSM 108614T=CECT 9740T); Salinispora goodfellowii sp. nov., CNY-666T (=DSM 108616T=CECT 9738T); Salinispora mooreana sp. nov., CNT-150T (=DSM 45549T=CECT 9741T); Salinispora oceanensis sp. nov., CNT-138T (=DSM 45547T=CECT 9742T); and Salinispora vitiensis sp. nov., CNT-148T (=DSM 45548T=CECT 9743T).

scholarly journals Genotypic Characterization of Multidrug-Resistant Pseudomonas aeruginosa Using Whole-Genome Sequencing

2021 ◽  
Vol 10 (32) ◽  
Author(s):  
Baha Abdalhamid ◽  
Itidal Reslane ◽  
Emily Mccutchen ◽  
Peter C. Iwen
Keyword(s):  
Health Care ◽  
Pseudomonas Aeruginosa ◽  
Draft Genome ◽  
Multidrug Resistant ◽  
Whole Genome ◽  
Significant Morbidity ◽  
Genome Sequences ◽  
Content Type ◽  
Human Infections

Multidrug-resistant Pseudomonas aeruginosa is a serious threat worldwide causing health care-acquired infections and is associated with significant morbidity and mortality. This report describes the draft genome sequences of five multidrug-resistant Pseudomonas aeruginosa strains isolated from human infections.

scholarly journals Adaptation-Based Resistance to Siderophore-Conjugated Antibacterial Agents by Pseudomonas aeruginosa

2013 ◽  
Vol 57 (9) ◽  
pp. 4197-4207 ◽  
Author(s):  
Andrew P. Tomaras ◽  
Jared L. Crandon ◽  
Craig J. McPherson ◽  
Mary Anne Banevicius ◽  
Steven M. Finegan ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antibacterial Agents ◽  
Iron Acquisition ◽  
Content Type ◽  
Multiple Strains ◽  
Resistance Rates ◽  
Assay Conditions

ABSTRACTMultidrug resistance in Gram-negative bacteria has become so threatening to human health that new antibacterial platforms are desperately needed to combat these deadly infections. The concept of siderophore conjugation, which facilitates compound uptake across the outer membrane by hijacking bacterial iron acquisition systems, has received significant attention in recent years. While standardin vitroMIC and resistance frequency methods demonstrate that these compounds are potent, broad-spectrum antibacterial agents whose activity should not be threatened by unacceptably high spontaneous resistance rates, recapitulation of these results in animal models can prove unreliable, partially because of the differences in iron availability in these different methods. Here, we describe the characterization of MB-1, a novel siderophore-conjugated monobactam that demonstrates excellentin vitroactivity againstPseudomonas aeruginosawhen tested using standard assay conditions. Unfortunately, thein vitrofindings did not correlate with thein vivoresults we obtained, as multiple strains were not effectively treated by MB-1 despite having low MICs. To address this, we also describe the development of newin vitroassays that were predictive of efficacy in mouse models, and we provide evidence that competition with native siderophores could contribute to the recalcitrance of someP. aeruginosaisolatesin vivo.

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