scholarly journals Hormones Can Influence Antibiotic Susceptibilities Even in Mono- and Co-Culture Conditions

2021 ◽  
Vol 4 (2) ◽  
pp. 39-49
Author(s):  
Fatma Kalaycı-Yüksek ◽  
Defne Gümüş ◽  
Mine Anğ-Küçüker
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Culture Conditions ◽  
Host Factors ◽  
Dependent Manner ◽  
Infectious Agents ◽  
Microdilution Method ◽  
Antibiotic Susceptibilities ◽  
Patient Groups ◽  
Strain Dependent

Abstract Pseudomonas aeruginosa and Staphylococcus aureus are known as important nosocomial infectious agents also their co-infections are commonly seen in some patient groups. It is well known that host factors such as hormones have roles in modulation of growth, pathogenesis and susceptibilities to antimicrobials. In our study, the influences of norepinephrine (NE) and melatonin (MEL) on antibiotic susceptibilities were examined in mono and co-culture conditions. Methicilin resistant Staphylococcus aureus (MRSA) ATCC 43300 and Pseudomonas aeruginosa ATCC 27853 were investigated to determine the minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) of ciprofloxacin and gentamicin in the absence/presence of NE (0.0017 and 0.04μg/mL) and MEL (6 and 60 pg/mL) by microdilution method in mono and co-culture. It was found that hormones decreased (among 2-64 fold) MIC and MBC values of both antibiotics for MRSA. However, it was shown that hormones had no effect on MIC values of both antibiotics for P. aeruginosa. MIC and MBC values of both antibiotics for co-culture were found to be reduced compared to monoculture of MRSA; were found to be increased compared to monoculture of P. aeruginosa. Whereas, hormones decreased MIC values of both antibiotics in co-culture conditions. Our results suggest that both hormones decreased MIC values and it seems that hormones could influence antibiotic susceptibilities in a strain-dependent manner.

scholarly journals Evaluation of the antibacterial and modulatory activities of ethanolic excract of Calotropis procera (Aiton) W.T. Aiton against multiresistant bacterial strains

2021 ◽  
pp. 205-209
Author(s):  
Yuri Geraldo ◽  
Livia Leandro ◽  
Ana Raquel Silva ◽  
Fábia Campina ◽  
Ana Carolina Araújo ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Inhibitory Concentration ◽  
Ethanolic Extract ◽  
Calotropis Procera ◽  
Subinhibitory Concentration ◽  
Bacterial Strains ◽  
Resistant Species ◽  
Microdilution Method

The objective of this study was to evaluate the antibacterial and modulatory activities of ethanolic extract of Calotropis procera (Aiton) W.T. Aiton against resistant species. By microdilution method, the minimum inhibitory concentration (MIC) of the extract and modulation of the subinhibitory concentration MIC/8 to norfloxacine, gentamicin and imipenem against Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. There was obtained 512 μg/mL to Pseudomonas aeruginosa. To Staphylococcus aureus, modulation showed synergism to norfloxacin and gentamicin, with imipenem against Pseudomonas aeruginosa and gentamicin against Escherichia coli. Based on these results, more studies are needed to test the antibacterial activity of the extract. El objetivo de este estudio fue evaluar la actividad antibacteriana y moduladora del extracto etanólico de Calotropis procera (Aiton) W.T. Aiton contra cepas multirresistentes de bacterias. Por el método de microdilución, fueron definidas la concentración inhibidora mínima (MIC) del extracto y la modulación con la concentración inhibidora CIM / 8 del extracto con norfloxacina, gentamicina e imipenem contra Staphylococcus aureus, Escherichia coli y Pseudomonas aeruginosa. Se obtuvo 512 μg/mL para Pseudomonas aeruginosa. Se descubrió sinergismo en el caso de Staphylococcus aureus, en la modulación con norfloxacina y gentamicina, mientras que con imipenem frente a Pseudomonas aeruginosa y con gentamicina para Escherichia coli. Con base en estos resultados, se necesitan más estudios para probar la actividad antibacteriana del extracto.

scholarly journals Optimal environmental and culture conditions allow the in vitro coexistence of Pseudomonas aeruginosa and Staphylococcus aureus in stable biofilms

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Maria del Mar Cendra ◽  
Núria Blanco-Cabra ◽  
Lucas Pedraz ◽  
Eduard Torrents
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Culture Media ◽  
Culture Conditions ◽  
Single Organism ◽  
Bacterial Fitness ◽  
Major Pathogens ◽  
And Staphylococcus Aureus ◽  
Stable Formation

Abstract The coexistence between species that occurs in some infections remains hard to achieve in vitro since bacterial fitness differences eventually lead to a single organism dominating the mixed culture. Pseudomonas aeruginosa and Staphylococcus aureus are major pathogens found growing together in biofilms in disease-affected lungs or wounds. Herein, we tested and analyzed different culture media, additives and environmental conditions to support P. aeruginosa and S. aureus coexistence in vitro. We have unraveled the potential of DMEM to support the growth of these two organisms in mature cocultured biofilms (three days old) in an environment that dampens the pH rise. Our conditions use equal initial inoculation ratios of both strains and allow the stable formation of separate S. aureus microcolonies that grow embedded in a P. aeruginosa biofilm, as well as S. aureus biofilm overgrowth when bovine serum albumin is added to the system. Remarkably, we also found that S. aureus survival is strictly dependent on a well-characterized phenomenon of oxygen stratification present in the coculture biofilm. An analysis of differential tolerance to gentamicin and ciprofloxacin treatment, depending on whether P. aeruginosa and S. aureus were growing in mono- or coculture biofilms, was used to validate our in vitro coculture conditions.

scholarly journals Bacterial Toxins Induce Sustained mRNA Expression of the Silencing Transcription Factor klf2 via Inactivation of RhoA and Rhophilin 1

2009 ◽  
Vol 77 (12) ◽  
pp. 5583-5592 ◽  
Author(s):  
Kristina Dach ◽  
Josip Zovko ◽  
Michael Hogardt ◽  
Isabel Koch ◽  
Katrin van Erp ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Transcription Factor ◽  
Serum Response Factor ◽  
De Novo ◽  
Virulence Plasmid ◽  
Dependent Manner ◽  
Expression Screening ◽  
Mrna Induction ◽  
Serum Response

ABSTRACTYersiniae bearing theYersiniavirulence plasmid pYV impact the transcriptome of J774A.1 macrophage-like cells in two distinct ways: (i) by suppressing, in aYersiniaouter protein P (YopP)-dependent manner, the induction of inflammatory response genes and (ii) by mRNA induction of the silencing transcription factorklf2. Here we show thatklf2induction byYersinia enterocoliticaoccurs in several cell lines of macrophage and squamous and upper gastrointestinal epithelial origin as well as in bone marrow-derived dendritic cells. Several strains ofPseudomonas aeruginosaandStaphylococcus aureusare equally effective asY. enterocoliticain inducingklf2expression. Screening of mutant strains or incubation with recombinant toxins identified the rho-inactivating toxins YopT fromYersiniaspp., ExoS fromPseudomonas aeruginosa, EDIN-B fromStaphylococcus aureus, and C3bot fromClostridium botulinumas bacterial inducers ofklf2mRNA.klf2mRNA induction by these toxins does not require de novo protein synthesis. Serum response factor or actin depolymerization does not seem to be involved in regulatingklf2expression in response to bacterial infection. Instead, short hairpin RNA-mediated inactivation of RhoA and its effector rhophilin 1 is sufficient to induce long-termklf2expression. Thus, bacteria exploit the RhoA-rhophilin signaling cascade to mediate sustained expression of the immunosuppressive transcription factorklf2.

scholarly journals Anti-Biofilm Effects of Synthetic Antimicrobial Peptides Against Drug-Resistant Pseudomonas aeruginosa and Staphylococcus aureus Planktonic Cells and Biofilm

Molecules ◽  
2019 ◽  
Vol 24 (24) ◽  
pp. 4560 ◽  
Author(s):  
Seong-Cheol Park ◽  
Min-Young Lee ◽  
Jin-Young Kim ◽  
Hyeonseok Kim ◽  
Myunghwan Jung ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Antimicrobial Peptides ◽  
Biofilm Formation ◽  
Extracellular Dna ◽  
Therapeutic Drug ◽  
Dependent Manner ◽  
Drug Resistant ◽  
And Staphylococcus Aureus

Biofilm-associated infections are difficult to manage or treat as biofilms or biofilm-embedded bacteria are difficult to eradicate. Antimicrobial peptides have gained increasing attention as a possible alternative to conventional drugs to combat drug-resistant microorganisms because they inhibit the growth of planktonic bacteria by disrupting the cytoplasmic membrane. The current study investigated the effects of synthetic peptides (PS1-2, PS1-5, and PS1-6) and conventional antibiotics on the growth, biofilm formation, and biofilm reduction of drug-resistant Pseudomonas aeruginosa and Staphylococcus aureus. The effects of PS1-2, PS1-5, and PS1-6 were also tested in vivo using a mouse model. All peptides inhibited planktonic cell growth and biofilm formation in a dose-dependent manner. They also reduced preformed biofilm masses by removing the carbohydrates, extracellular DNA, and lipids that comprised extracellular polymeric substances (EPSs) but did not affect proteins. In vivo, PS1-2 showed the greatest efficacy against preformed biofilms with no cytotoxicity. Our findings indicate that the PS1-2 peptide has potential as a next-generation therapeutic drug to overcome multidrug resistance and to regulate inflammatory response in biofilm-associated infections.

scholarly journals Disinfectant Efficacy Against Dry Surface Biofilms of Staphylococcus Aureus and Pseudomonas Aeruginosa Is Product, Time Point and Strain Dependent

2021 ◽  
Author(s):  
Carine A Nkemngong ◽  
Gurpreet K Chaggar ◽  
Xiaobao Li ◽  
Peter J Teska ◽  
Haley F Oliver
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Quaternary Ammonium ◽  
Healthcare Delivery ◽  
Significant Difference ◽  
Strain Type ◽  
Healthcare Associated ◽  
Ammonium Compounds ◽  
Strain Dependent ◽  
Disinfectant Efficacy

Abstract Background: Globally, healthcare associated infections (HAI) are the most frequent adverse outcome in healthcare delivery. Although bacterial biofilms contribute significantly to the incidence of HAI, few studies have investigated the efficacy of common disinfectants against dry surface biofilms (DSB). The objective of this study was to evaluate the bactericidal efficacy of seven disinfectants against DSB of Staphylococcus aureus and Pseudomonas aeruginosa. We hypothesized that overall, hydrogen peroxides, sodium dichloro-s-triazinetrione and quaternary ammonium compounds plus alcohol disinfectants will be more bactericidal against DSB than quaternary ammonium. We also hypothesized that regardless of differences in product chemistries, higher bactericidal efficacies against DSB will be exhibited after 24 h of dehydration compared to 72 h.Methods: Wet surface biofilms of S. aureus and P. aeruginosa were grown following EPA-MLB-SOP-MB-19 and dehydrated for 24 h and 72 h to establish DSB. Seven EPA-registered disinfectants were tested against dehydrated DSB following EPA-MLB-SOP-MB-20. Results: Overall, quaternary ammonium plus alcohol, sodium dichloro-s-triazinetrione, and hydrogen peroxide products were more efficacious against DSB than quaternary ammoniums for both tested strains. While there was no significant difference in biofilm killing efficacies between 24 h and 72 h S. aureus biofilms, significantly higher log10 reductions were observed when products were challenged with 24 h P. aeruginosa DSB compared to 72 h P. aeruginosa DSB. Conclusion: Strain type, active ingredient class, and dry time significantly impact disinfectant efficacy against DSB of S. aureus or P. aeruginosa.

Moxifloxacin Loaded Lipidic Nanoparticles for Antimicrobial Efficacy

2020 ◽  
Vol 26 ◽  
Author(s):  
Mohammad Darvishi ◽  
Shahrzad Farahani ◽  
Azadeh Haeri
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Antimicrobial Properties ◽  
Free Drug ◽  
Molar Ratio ◽  
Pulmonary Infections ◽  
Microdilution Method ◽  
Current Therapies ◽  
Sonication Technique ◽  
And Staphylococcus Aureus

Background: Pulmonary infections are an increasing problem in individuals and current therapies are lacking. Liposomes are spherical lipidic vesicles composed of phospholipid and cholesterol. Liposomes have numerous advantages, such as biodegradability, biocompatibility, non-immunogenicity, lack of toxicity, controlled release properties and high stability. Objective: This work was carried out to construct a novel liposomal moxifloxacin formulation and examine its antimicrobial effects against Pseudomonas aeruginosa and Staphylococcus aureus. Methods: The liposomal moxifloxacin formulation was prepared by the thin film hydration method. The bilayer was composed of cholesterol and phospholipid at 30:70 molar ratio. To prepare cationic liposomes 5% cationic agent (CTAB) was added. The liposomes were sized down with bath sonication technique. The liposomal characterizations were tested regarding vesicle size, surface charge and drug encapsulation efficacy. Microdilution method was used to determine the Minimum Inhibitory Concentration (MIC) for Pseudomonas aeruginosa and Staphylococcus aureus of free drug, neutral and cationic moxifloxacin liposomes. Results: The size of liposomes was 50-70 nm. The zeta potential of neutral and cationic vesicles was ~ 0 and +22 mV. The MIC values to Pseudomonas aeruginosa of free drug, neutral and cationic moxifloxacin liposomes were 10, 5 and 2.5, respectively. The MICs against Staphylococcus aureus of free drug, neutral and cationic moxifloxacin liposomes were 1, 1 and 0.5, respectively. Conclusion: This study demonstrates that the encapsulation of moxifloxacin into liposomes (especially cationic vesicles) could enhance antimicrobial properties.

Two forms of Staphylococcus aureus in blood of patients with staphylococcal sepsis

1979 ◽  
Vol 9 (1) ◽  
pp. 23-27
Author(s):  
D M Musher ◽  
R E Baughn ◽  
E J Young
Keyword(s):  
Staphylococcus Aureus ◽  
The Other ◽  
Host Factors ◽  
Biochemical Reactions ◽  
Phage Types ◽  
Antibiotic Susceptibilities ◽  
Stable Forms

Two distinctly different and stable forms of Staphylococcus aureus were isolated from the blood of each of two patients with staphylococcal sepsis. In each case, one form was hemolytic and the other nonhemolytic, although both had the same biochemical reactions, phage types, and antibiotic susceptibilities, and both were virulent for mice. Variant forms of S. aureus may be selected in vivo by host factors and may be responsible for causing and/or perpetuating infection.

Glycoprotein 340’s scavenger receptor cysteine-rich domain promotes adhesion of Staphylococcus aureus and Pseudomonas aeruginosa to contact lens polymers.

2021 ◽  
Author(s):  
Kwaku A. Osei ◽  
Joshua L. Mieher ◽  
Manisha Patel ◽  
Jason J. Nichols ◽  
Champion Deivanayagam
Keyword(s):  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Contact Lens ◽  
Bacterial Adhesion ◽  
Scavenger Receptor ◽  
Surface Proteins ◽  
Microbial Colonization ◽  
Dependent Manner ◽  
Microbial Keratitis ◽  
Tear Proteins

Contact lenses are biomaterials worn on the eye to correct refractive errors. Bacterial adhesion and colonization of these lenses results in adverse events such as microbial keratitis. The adsorption of tear proteins to contact lens materials enhances bacterial adhesion. Glycoprotein 340 (Gp340), a tear component, is known to promote microbial colonization in the oral cavity, however, it has not been investigated in any contact lens-related adverse event. Therefore, this study examined the adsorption of Gp340 and its recombinantly expressed scavenger receptor cysteine rich ( i SRCR 1 Gp340 ) domain on two common contact lens materials, etafilcon A and lotrafilcon B, and the concomitant effects on the adherence of clinical isolates of microbial keratitis causative agents, Pseudomonas aeruginosa (PA6206, PA6294), and Staphylococcus aureus (SA38, USA300). Across all strains and materials, i SRCR 1 Gp340 enhanced adherence of bacteria in a dose-dependent manner. However, i SRCR 1 Gp340 did not modulate lysozyme’s and lactoferrin’s effects on bacterial adhesion to the contact lens. The Gp340 binding surface protein SraP significantly enhanced USA300 binding to i SRCR 1 Gp340 -coated lenses. In addition, i SRCR 1 Gp340 -coated surfaces had significantly diminished biofilms with the SraP mutant (ΔSraP ), and with the Sortase A mutant (ΔSrtA ), there was a further reduction in biofilms, indicating the likely involvement of additional surface proteins. Finally, the binding affinities between i SRCR 1 Gp340 and SraP were determined using surface plasmon resonance (SPR), where the complete SraP binding region displayed nanomolar affinity, whereas its smaller fragments adhered with micromolar affinities. This study concludes that Gp340 and its SRCR domains play an important role in bacterial adhesion to the contact lens.

scholarly journals Coculture of Staphylococcus aureus with Pseudomonas aeruginosa Drives S. aureus towards Fermentative Metabolism and Reduced Viability in a Cystic Fibrosis Model

2015 ◽  
Vol 197 (14) ◽  
pp. 2252-2264 ◽  
Author(s):  
Laura M. Filkins ◽  
Jyoti A. Graber ◽  
Daniel G. Olson ◽  
Emily L. Dolben ◽  
Lee R. Lynd ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Early Adulthood ◽  
Aerobic Respiration ◽  
Dependent Manner ◽  
Microbial Composition ◽  
Content Type ◽  
Coculture System

ABSTRACTThe airways of patients with cystic fibrosis are colonized with diverse bacterial communities that change dynamically during pediatric years and early adulthood.Staphylococcus aureusis the most prevalent pathogen during early childhood, but during late teens and early adulthood, a shift in microbial composition occurs leading toPseudomonas aeruginosacommunity predominance in ∼50% of adults. We developed a robust dual-bacterialin vitrococulture system ofP. aeruginosaandS. aureuson monolayers of human bronchial epithelial cells homozygous for the ΔF508 cystic fibrosis transmembrane conductance regulator (CFTR) mutation to better model the mechanisms of this interaction. We show thatP. aeruginosadrives theS. aureusexpression profile from that of aerobic respiration to fermentation. This shift is dependent on the production of both 2-heptyl-4-hydroxyquinolineN-oxide (HQNO) and siderophores byP. aeruginosa. Furthermore,S. aureus-produced lactate is a carbon source thatP. aeruginosapreferentially consumes over medium-supplied glucose. We find that initiallyS. aureusandP. aeruginosacoexist; however, over extended cocultureP. aeruginosareducesS. aureusviability, also in an HQNO- andP. aeruginosasiderophore-dependent manner. Interestingly,S. aureussmall-colony-variant (SCV) genetic mutant strains, which have defects in their electron transport chain, experience reduced killing byP. aeruginosacompared to their wild-type parent strains; thus, SCVs may provide a mechanism for persistence ofS. aureusin the presence ofP. aeruginosa. We propose that the mechanism ofP. aeruginosa-mediated killing ofS. aureusis multifactorial, requiring HQNO andP. aeruginosasiderophores as well as additional genetic, environmental, and nutritional factors.IMPORTANCEIn individuals with cystic fibrosis,Staphylococcus aureusis the primary respiratory pathogen during childhood. During adulthood,Pseudomonas aeruginosapredominates and correlates with worse patient outcome. The mechanism(s) by whichP. aeruginosaoutcompetes or killsS. aureusis not well understood. We describe anin vitrodual-bacterial species coculture system on cystic fibrosis-derived airway cells, which models interactions relevant to patients with cystic fibrosis. Further, we show that molecules produced byP. aeruginosaadditively induce a transition ofS. aureusmetabolism from aerobic respiration to fermentation and eventually lead to loss ofS. aureusviability. Elucidating the molecular mechanisms ofP. aeruginosacommunity predominance can provide new therapeutic targets and approaches to impede this microbial community transition and subsequent patient worsening.

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