scholarly journals Salmonella Typhimurium and Pseudomonas aeruginosa Respond Differently to the Fe Chelator Deferiprone and to Some Novel Deferiprone Derivatives

2021 ◽  
Vol 22 (19) ◽  
pp. 10217
Author(s):  
Serena Ammendola ◽  
Valerio Secli ◽  
Francesca Pacello ◽  
Martina Bortolami ◽  
Fabiana Pandolfi ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Salmonella Typhimurium ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Chelating Agent ◽  
Gram Negative ◽  
Pseudomonas Aeruginosa Pao1 ◽  
Significant Interest ◽  
Serovar Typhimurium ◽  
Fe Homeostasis ◽  
Fluorescent Derivative

The ability to obtain Fe is critical for pathogens to multiply in their host. For this reason, there is significant interest in the identification of compounds that might interfere with Fe management in bacteria. Here we have tested the response of two Gram-negative pathogens, Salmonella enterica serovar Typhimurium (STM) and Pseudomonas aeruginosa (PAO1), to deferiprone (DFP), a chelating agent already in use for the treatment of thalassemia, and to some DFP derivatives designed to increase its lipophilicity. Our results indicate that DFP effectively inhibits the growth of PAO1, but not STM. Similarly, Fe-dependent genes of the two microorganisms respond differently to this agent. DFP is, however, capable of inhibiting an STM strain unable to synthesize enterochelin, while its effect on PAO1 is not related to the capability to produce siderophores. Using a fluorescent derivative of DFP we have shown that this chelator can penetrate very quickly into PAO1, but not into STM, suggesting that a selective receptor exists in Pseudomonas. Some of the tested derivatives have shown a greater ability to interfere with Fe homeostasis in STM compared to DFP, whereas most, although not all, were less active than DFP against PAO1, possibly due to interference of the added chemical tails with the receptor-mediated recognition process. The results reported in this work indicate that DFP can have different effects on distinct microorganisms, but that it is possible to obtain derivatives with a broader antimicrobial action.

Sensitization of Outer-Membrane Mutants of Salmonella Typhimurium and Pseudomonas aeruginosa to Antimicrobial Peptides under High Pressure

2003 ◽  
Vol 66 (8) ◽  
pp. 1360-1367 ◽  
Author(s):  
BARBARA MASSCHALCK ◽  
DAPHNE DECKERS ◽  
CHRIS W. MICHIELS
Keyword(s):  
Pseudomonas Aeruginosa ◽  
High Pressure ◽  
Antimicrobial Peptides ◽  
Salmonella Typhimurium ◽  
Outer Membrane ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Polymyxin B ◽  
Membrane Properties ◽  
Bacterial Populations ◽  
Serovar Typhimurium

High pressure can sensitize gram-negative bacteria to antimicrobial peptides or proteins through the permeabilization of their outer membranes; however, the range of compounds to which sensitivity is induced is species and strain dependent. We studied the role of outer-membrane properties in this sensitization by making use of a series of rough and deep rough mutants of Salmonella enterica serovar Typhimurium that show an increased degree of lipopolysaccharide(LPS) truncation, along with Pseudomonas aeruginosa PhoP and PhoQ mutants with altered outer-membrane properties. The outer-membrane properties of P. aeruginosa were also modulated through the use of different Mg2+ concentrations in the growth medium. Each of these strains was challenged under high pressure (15 min at 270 MPa for Salmonella Typhimurium and 15 min at 100 MPa for P. aeruginosa) in phosphate buffer with lysozyme (100 μg/ml), nisin (100 IU/ml), lactoferricin (20 μg/ml), and HEL96-116 (100 μg/ml), a synthetic lysozyme-derived peptide, and sensitization levels were compared. The results obtained indicated that outer-membrane properties affected high-pressure sensitization differently for different compounds. LPS truncation in Salmonella Typhimurium was correlated with increased sensitization to lysozyme (up to 1.5 log10 units) and nisin (up to 1.2 log10 units) but with decreased sensitization to lactoferricin under pressure. For P. aeruginosa, the pattern of sensitization to lactoferricin and nisin resembled that of polymyxin B at atmospheric pressure, suggesting that pressure induces the self-promoted uptake of both peptides. Sensitization to HEL96-116 was not affected by outer-membrane properties for either organism. Hence, outer-membrane permeabilization by high pressure cannot be explained by a single unifying mechanism and is dependent on the organism, the outer-membrane properties, and the nature of the antimicrobial compound. On the basis of these findings, the use of antimicrobial cocktails targeting different bacteria and fractions of bacterial populations may enhance the efficacy of high pressure as a preservation treatment.

Detection of Virulence Plasmid–Encoded Genes in Salmonella Typhimurium and Salmonella Kentucky Isolates Recovered from Commercially Processed Chicken Carcasses

2019 ◽  
Vol 82 (8) ◽  
pp. 1364-1368 ◽  
Author(s):  
RIZWANA TASMIN ◽  
PAUL A. GULIG ◽  
SALINA PARVEEN
Keyword(s):  
United States ◽  
Salmonella Typhimurium ◽  
Virulence Genes ◽  
Salmonella Enterica Serovar Typhimurium ◽  
The United States ◽  
Clinical Isolates ◽  
Virulence Plasmid ◽  
Chicken Carcass ◽  
Serovar Typhimurium ◽  
Salmonella Virulence

ABSTRACT Salmonella enterica serovar Typhimurium is one of the leading causes of nontyphoidal gastroenteritis of humans in the United States. Commercially processed poultry carcasses are frequently contaminated with Salmonella serovar Kentucky in the United States. The aim of the study was to detect the Salmonella virulence plasmid containing the spv genes from Salmonella isolates recovered from commercially processed chicken carcasses. A total of 144 Salmonella isolates (Salmonella Typhimurium, n = 72 and Salmonella Kentucky, n = 72) were used for isolation of plasmids and detection of corresponding virulence genes (spvA, spvB, and spvC). Only four (5.5%) Salmonella Typhimurium isolates tested positive for all three virulence genes and hence were classified as possessing the virulence plasmid. All isolates of Salmonella Kentucky were negative for the virulence plasmid and genes. These results indicate that the virulence plasmid, which is very common among clinical isolates of Typhimurium and other Salmonella serovars (e.g., Enteritidis, Dublin, Choleraesuis, Gallinarum, Pullorum, and Abortusovis), may not be present in a significant portion of commercially processed chicken carcass isolates.

scholarly journals CpxR regulates the colistin susceptibility of Salmonella Typhimurium by a multitarget mechanism

2020 ◽  
Vol 75 (10) ◽  
pp. 2780-2786 ◽  
Author(s):  
Ya-Jun Zhai ◽  
Hua-Run Sun ◽  
Xing-Wei Luo ◽  
Jian-Hua Liu ◽  
Yu-Shan Pan ◽  
...  
Keyword(s):  
Salmonella Typhimurium ◽  
Target Genes ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Efflux Pump ◽  
Colistin Resistance ◽  
Mobility Shift ◽  
Serovar Typhimurium ◽  
Electrophoretic Mobility Shift Assays ◽  
First Time ◽  
Signalling Systems

Abstract Background The two-component signalling systems PmrAB and PhoPQ of Salmonella have been extensively studied with regard to colistin resistance. We previously showed that overexpressed CpxR could significantly increase the colistin susceptibility (16-fold compared with the WT strain) of Salmonella enterica serovar Typhimurium (Salmonella Typhimurium) through PmrAB and PhoPQ. Objectives To identify the potential target genes of CpxR in PmrAB- and PhoPQ-related signalling pathways. Methods His6-CpxR was prokaryotically expressed and purified by Ni-NTA resin affinity chromatography. β-Galactosidase activity assays were conducted to investigate whether CpxR could regulate the promoters of colistin resistance-related genes (CRRGs). Electrophoretic mobility shift assays (EMSAs) were used to further detect His6-CpxR complexes with promoters of CRRGs. Results We demonstrated for the first time (to the best of our knowledge) that CpxR and the AcrAB–TolC efflux pump have reciprocal effects on CRRG transcription. Additionally, CpxR could regulate the colistin susceptibility of Salmonella Typhimurium by binding directly to the promoters of phoPQ, pmrC, pmrH and pmrD at the CpxR box-like sequences or indirectly through other regulators including pmrAB and mgrB. Conclusions CpxR could regulate the colistin susceptibility of Salmonella Typhimurium by a multitarget mechanism.

scholarly journals Complete Genome Sequence of Salmonella enterica Serovar Typhimurium Siphophage Skate

2019 ◽  
Vol 8 (27) ◽  
Author(s):  
Matthew Rohren ◽  
Yicheng Xie ◽  
Chandler O’Leary ◽  
Rohit Kongari ◽  
Jason Gill ◽  
...  
Keyword(s):  
Genome Sequence ◽  
Complete Genome Sequence ◽  
Salmonella Enterica ◽  
Complete Genome ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Foodborne Illnesses ◽  
Gram Negative ◽  
Content Type ◽  
Typhimurium Strain ◽  
Serovar Typhimurium

ABSTRACT Salmonella enterica serovar Typhimurium is a Gram-negative pathogen and a primary cause of foodborne illnesses worldwide. Here, we present the complete 47,393-bp genome sequence of the siphophage Skate, which was isolated against S. Typhimurium strain LT2.

Fate of Staphylococcus aureus, Salmonella enterica Serovar Typhimurium, and Vibrio vulnificus in Raw Oysters Treated with Chitosan

2006 ◽  
Vol 69 (7) ◽  
pp. 1600-1604 ◽  
Author(s):  
PALLAVI CHHABRA ◽  
YAO-WEN HUANG ◽  
JOSEPH F. FRANK ◽  
REVIS CHMIELEWSKI ◽  
KEITH GATES
Keyword(s):  
Staphylococcus Aureus ◽  
Hydrochloric Acid ◽  
Salmonella Typhimurium ◽  
Salmonella Enterica ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Vibrio Vulnificus ◽  
Storage Period ◽  
Major Effect ◽  
Chitosan Concentration ◽  
Serovar Typhimurium

The fate of Staphylococcus aureus, Salmonella enterica serovar Typhimurium, and Vibrio vulnificus in oysters treated with chitosan was investigated. Three concentrations (0.5, 1.0, and 2.0%) of chitosan in 0.5% hydrochloric acid were prepared and coated onto raw oysters, which were then stored at 4°C for 12 days. Untreated oysters and oysters coated with 0.5% hydrochloric acid without chitosan were used as controls. S. aureus cells were most sensitive to 2.0% chitosan followed by 0.5 and 1.0%. In general, chitosan treatment of oysters produced a decline in the population of S. aureus by 1 to 4 log CFU/ml compared with the untreated control. Chitosan treatment had no influence on the reduction of Salmonella Typhimurium over the 12-day storage period; inhibition of Salmonella Typhimurium growth was similar in both the control samples and the chitosan-treated samples. However, time of storage had a major effect on the survival of Salmonella Typhimurium on oysters. Neither time nor chitosan concentration had a significant effect on the growth of V. vulnificus during storage. All treatments were similar in inhibiting V. vulnificus growth.

Metal binding by Pseudomonas aeruginosa PAO1 is influenced by growth of the cells as a biofilm

1999 ◽  
Vol 45 (7) ◽  
pp. 616-622 ◽  
Author(s):  
S Langley ◽  
T J Beveridge
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Metal Binding ◽  
Gram Negative Bacteria ◽  
Binding Properties ◽  
Gram Negative ◽  
Pseudomonas Aeruginosa Pao1

The metal-binding properties of Pseudomonas aeruginosa PAO1 biofilms were investigated using four metals (Cu, Fe, Au, and La). All but one of the metals (i.e., Cu) were bound by the biofilms in amounts that were significantly greater than those bound by planktonically grown cells of the same strain. Lanthanum precipitation appeared to be limited to the base of the biofilms and was not promoted by a shift in lipopolysaccharide production by the cells.Key words: metal binding, biofilms, Gram-negative bacteria, bioremediation.

MDR Salmonella enterica serovar Typhimurium ST34 carrying mcr-1 isolated from cases of bloodstream and intestinal infection in children in China

2019 ◽  
Vol 75 (1) ◽  
pp. 92-95 ◽  
Author(s):  
Qixia Luo ◽  
Fen Wan ◽  
Xiao Yu ◽  
Beiwen Zheng ◽  
Yunbo Chen ◽  
...  
Keyword(s):  
Salmonella Typhimurium ◽  
Salmonella Enterica ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Heavy Metal Resistance ◽  
Metal Resistance ◽  
Ecological Niches ◽  
Salmonella Infection ◽  
Serovar Typhimurium ◽  
Multiple Resistance Genes ◽  
Tn7 Transposition

Abstract Objectives Children are vulnerable to Salmonella infection due to their immature immune system. Cases of infection with mcr-1-harbouring Salmonella in child inpatients have not been reported in China before. Methods Salmonella isolates from gastroenteritis and bacteraemia were screened using primers targeting mcr-1. Complete genome sequences of mcr-1-harbouring isolates were determined using the PacBio RS II platform. The transferability of mcr-1-harbouring plasmids was verified by conjugation. Results We investigated two mcr-1-carrying polymyxin-resistant Salmonella enterica serovar Typhimurium ST34 isolates, S61394 and S44712, from bloodstream and intestinal Salmonella infection of two child inpatients, respectively. Both isolates were non-susceptible to commonly used antibiotics for children that compromised the success of clinical treatment and infection control. The mcr-1-harbouring plasmids pLS61394-MCR and pLS44712-MCR (from S61394 and S44712, respectively) were both conjugative pHNSHP45-2-like IncHI2-type epidemic plasmids carrying multiple resistance genes. Compared with pHNSHP45-2, a ∼33 kb insertion region encoding Tn7 transposition protein and heavy metal resistance proteins was identified in pLS61394-MCR, which might enhance adaptation of bacteria carrying this plasmid to various ecological niches. The phylogenetic tree of worldwide mcr-harbouring Salmonella indicated a host preference of mcr and a worldwide and cross-sectoral prevalence of the mcr-positive Salmonella ST34 clone. Conclusions To our knowledge, for the first time we report completed whole genomes of mcr-1-positive MDR Salmonella Typhimurium ST34 isolated from infected children in China, suggesting that improved surveillance is imperative for tackling the dissemination of mcr-harbouring MDR Salmonella Typhimurium ST34.

Molybdenum Binding by Pseudomonas aeruginosa

1986 ◽  
Vol 39 (8) ◽  
pp. 1205 ◽  
Author(s):  
S Stojkovski ◽  
RJ Magee ◽  
J Liesegang
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Uronic Acid ◽  
Extracellular Polysaccharide ◽  
Uronic Acids ◽  
Negative Bacterium ◽  
Molybdenum Complex ◽  
Gram Negative ◽  
Pseudomonas Aeruginosa Pao1 ◽  
Polysaccharide Layer

The uptake of molybdenum by certain bacteria hinders its role as a trace metal in the micronutrients for plant growth. The binding of molybdenum by the Gram-negative bacterium Pseudomonas aeruginosa, PAO1, has been investigated. A molybdenum complex of uronic acid, which forms in the extracellular polysaccharide layer (slime), was isolated and characterized by a variety of techniques. Comparisons with 'mimic' compounds of uronic acids suggest that Pseudomonas aeruginosa, PAO1, produces a binuclear, di-oxo-bridged magnesium salt MgMo2O4(C6H8O7)2.5H2O; this indicates the important role of uronic acids in metallic uptake by bacteria.

Effectiveness of Sanitizing Products on Controlling Selected Pathogen Surrogates on Retail Deli Slicers

2015 ◽  
Vol 78 (4) ◽  
pp. 707-715 ◽  
Author(s):  
MICHAEL C. YEATER ◽  
KATIE R. KIRSCH ◽  
T. MATTHEW TAYLOR ◽  
JEFF MITCHELL ◽  
WESLEY N. OSBURN
Keyword(s):  
High Risk ◽  
Salmonella Typhimurium ◽  
Ammonium Chloride ◽  
Quaternary Ammonium ◽  
Salmonella Enterica Serovar Typhimurium ◽  
Bacterial Attachment ◽  
Listeria Innocua ◽  
Serovar Typhimurium ◽  
Treatment Interaction ◽  
Quaternary Ammonium Chloride

The objectives of this study were (i) to assess the efficacy of quaternary ammonium chloride–based wet foam (WF) and dry foam (DF) sanitizer systems (600 ppm) for reducing Listeria innocua (a nonpathogenic surrogate of Listeria monocytogenes) or a 100.0 μg/ml rifampin-resistant Salmonella Typhimurium LT2 (a nonpathogenic surrogate of Salmonella enterica serovar Typhimurium) on niche and transfer point areas of an unwashed retail deli slicer as compared with traditional chlorine (Cl−) treatment (200 ppm) and (ii) to compare sanitizer surface contact times (10 and 15 min) for pathogen surrogate control. Turkey frankfurter slurries inoculated with L. innocua or Salmonella Typhimurium were used to inoculate seven high-risk sites on a commercial slicer. After 30 min of bacterial attachment, slicers were dry wiped to remove excess food matter, followed by a randomly assigned sanitizer treatment. Surviving pathogen surrogate cells were enumerated on modified Oxford's agar not containing antimicrobic supplement (L. innocua) or on tryptic soy agar supplemented with 100 μg/ml rifampin (Salmonella Typhimurium LT2). Replicate-specific L. innocua and Salmonella Typhimurium reductions were calculated as log CFU per square centimeter of control minus log CFU per square centimeter of enumerated survivors for each site. For both organisms, all sanitizer treatments differed from each other, with Cl− producing the least reduction and WF the greatest reduction. A significant (P < 0.05) site-by-treatment interaction was observed. The results of the study indicate that quaternary ammonium chloride sanitizers (600 ppm) applied by both WF and DF were more effective at reducing L. innocua and Salmonella Typhimurium than a traditional Cl sanitizer (200 ppm) on unwashed slicer surfaces.

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