scholarly journals Hydrogen Peroxide-Mediated Interference Competition by Streptococcus pneumoniae Has No Significant Effect on Staphylococcus aureus Nasal Colonization of Neonatal Rats

2008 ◽  
Vol 191 (2) ◽  
pp. 571-575 ◽  
Author(s):  
Elisa Margolis
Keyword(s):  
Hydrogen Peroxide ◽  
Staphylococcus Aureus ◽  
Streptococcus Pneumoniae ◽  
Interference Competition ◽  
Inhibitory Effect ◽  
Nasal Colonization ◽  
Neonatal Rats ◽  
Mixed Inoculum ◽  
Relative Scarcity

ABSTRACT It has been proposed that the relative scarcity of Staphylococcus aureus and Streptococcus pneumoniae cocolonization in the nasopharynxes of humans can be attributed to hydrogen peroxide-mediated interference competition. Previously it has been shown in vitro that H2O2 produced by S. pneumoniae is bactericidal to S. aureus. To ascertain whether H2O2 has this inhibitory effect in the nasal passages of neonatal rats, colonization experiments were performed with S. aureus and S. pneumoniae. The results of these experiments with neonatal rats are inconsistent with the hypothesis that hydrogen peroxide-mediated killing of S. aureus by S. pneumoniae is responsible for the relative scarcity of cocolonization by these bacteria. In mixed-inoculum colonization experiments and experiments where S. aureus invaded the nasopharynxes of rats with established S. pneumoniae populations, the density of S. aureus did not differ whether the S. pneumoniae strain was H2O2 secreting or non-H2O2 secreting (SpxB). Moreover, the advantage of catalase production by S. aureus in competition with a non-catalase-producing strain (KatA) during nasal colonization was no greater in the presence of H2O2-producing S. pneumoniae than in the presence of non-H2O2-producing S. pneumoniae.

scholarly journals Inhibitory Effect of Biocides on the Viable Masses and Matrices of Staphylococcus aureus and Pseudomonas aeruginosa Biofilms

2010 ◽  
Vol 76 (10) ◽  
pp. 3135-3142 ◽  
Author(s):  
K. Toté ◽  
T. Horemans ◽  
D. Vanden Berghe ◽  
L. Maes ◽  
P. Cos
Keyword(s):  
Hydrogen Peroxide ◽  
Staphylococcus Aureus ◽  
Pseudomonas Aeruginosa ◽  
Sodium Hypochlorite ◽  
Peracetic Acid ◽  
Inhibitory Effect ◽  
European Guidelines ◽  
The Matrix ◽  
Antibiofilm Agents

ABSTRACT Bacteria and matrix are essential for the development of biofilms, and assays should therefore target both components. The current European guidelines for biocidal efficacy testing are not adequate for sessile microorganisms; hence, alternative discriminatory test protocols should be used. The activities of a broad range of biocides on Staphylococcus aureus and Pseudomonas aeruginosa biofilms were evaluated using such in vitro assays. Nearly all selected biocides showed a significant decrease in S. aureus biofilm viability, with sodium hypochlorite and peracetic acid as the most active biocides. Only hydrogen peroxide and sodium hypochlorite showed some inhibitory effect on the matrix. Treatment of P. aeruginosa biofilms was roughly comparable to that of S. aureus biofilms. Peracetic acid was the most active on viable mass within 1 min of contact. Isopropanol ensured a greater than 99.999% reduction of P. aeruginosa viability after at least 30 min of contact. Comparable to results with S. aureus, sodium hypochlorite and hydrogen peroxide markedly reduced the P. aeruginosa matrix. This study clearly demonstrated that despite their aspecific mechanisms of action, most biocides were active only against biofilm bacteria, leaving the matrix undisturbed. Only hydrogen peroxide and sodium hypochlorite were active on both the biofilm matrix and the viable mass, making them the better antibiofilm agents. In addition, this study emphasizes the need for updated and standardized guidelines for biofilm susceptibility testing of biocides.

scholarly journals Interference between Streptococcus pneumoniae and Staphylococcus aureus: In Vitro Hydrogen Peroxide-Mediated Killing by Streptococcus pneumoniae

2006 ◽  
Vol 188 (13) ◽  
pp. 4996-5001 ◽  
Author(s):  
Gili Regev-Yochay ◽  
Krzysztof Trzciński ◽  
Claudette M. Thompson ◽  
Richard Malley ◽  
Marc Lipsitch
Keyword(s):  
Hydrogen Peroxide ◽  
Staphylococcus Aureus ◽  
Streptococcus Pneumoniae ◽  
Bactericidal Activity ◽  
Mechanistic Explanation ◽  
Epidemiologic Studies ◽  
Pyruvate Oxidase ◽  
And Staphylococcus Aureus

ABSTRACT The bactericidal activity of Streptococcus pneumoniae toward Staphylococcus aureus is mediated by hydrogen peroxide. Catalase eliminated this activity. Pneumococci grown anaerobically or genetically lacking pyruvate oxidase (SpxB) were not bactericidal, nor were nonpneumococcal streptococci. These results provide a possible mechanistic explanation for the interspecies interference observed in epidemiologic studies.

scholarly journals Role of Staphylococcus aureus Catalase in Niche Competition against Streptococcus pneumoniae

2008 ◽  
Vol 190 (7) ◽  
pp. 2275-2278 ◽  
Author(s):  
Bonggoo Park ◽  
Victor Nizet ◽  
George Y. Liu
Keyword(s):  
Staphylococcus Aureus ◽  
Streptococcus Pneumoniae ◽  
Murine Model ◽  
Targeted Mutagenesis ◽  
Nasal Colonization ◽  
Subsequent Infection ◽  
Predisposing Factor ◽  
Niche Competition

ABSTRACT Nasal colonization by Staphylococcus aureus is a major predisposing factor for subsequent infection. Recent reports of increased S. aureus colonization among children receiving pneumococcal vaccine implicate Streptococcus pneumoniae as an important competitor for the same niche. Since S. pneumoniae uses H2O2 to kill competing bacteria, we hypothesized that oxidant defense could play a significant role in promoting S. aureus colonization of the nasal mucosa. Using targeted mutagenesis, we showed that S. aureus expression of catalase contributes significantly to the survival of this pathogen in the presence of S. pneumoniae both in vitro and in a murine model of nasal cocolonization.

scholarly journals Interaction between Streptococcus pneumoniae and Staphylococcus aureus Generates ·OH Radicals That Rapidly Kill Staphylococcus aureus Strains

2019 ◽  
Vol 201 (21) ◽  
Author(s):  
Xueqing Wu ◽  
Oren Gordon ◽  
Wenxin Jiang ◽  
Brenda S. Antezana ◽  
Uriel A. Angulo-Zamudio ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Staphylococcus Aureus ◽  
Streptococcus Pneumoniae ◽  
Hydroxyl Radical ◽  
Hydroxyl Radicals ◽  
Sublethal Dose ◽  
Oh Radicals ◽  
Upper Airways ◽  
Content Type

ABSTRACT Streptococcus pneumoniae rapidly kills Staphylococcus aureus by producing membrane-permeable hydrogen peroxide (H2O2). The mechanism by which S. pneumoniae-produced H2O2 mediates S. aureus killing was investigated. An in vitro model that mimicked S. pneumoniae-S. aureus contact during colonization of the nasopharynx demonstrated that S. aureus killing required outcompeting densities of S. pneumoniae. Compared to the wild-type strain, isogenic S. pneumoniae ΔlctO and S. pneumoniae ΔspxB, both deficient in production of H2O2, required increased density to kill S. aureus. While residual H2O2 activity produced by single mutants was sufficient to eradicate S. aureus, an S. pneumoniae ΔspxB ΔlctO double mutant was unable to kill S. aureus. A collection of 20 diverse methicillin-resistant S. aureus (MRSA) and methicillin-susceptible S. aureus (MSSA) strains showed linear sensitivity (R2 = 0.95) for S. pneumoniae killing, but the same strains had different susceptibilities when challenged with pure H2O2 (5 mM). There was no association between the S. aureus clonal complex and sensitivity to either S. pneumoniae or H2O2. To kill S. aureus, S. pneumoniae produced ∼180 μM H2O2 within 4 h of incubation, while the killing-defective S. pneumoniae ΔspxB and S. pneumoniae ΔspxB ΔlctO mutants produced undetectable levels. Remarkably, a sublethal dose (1 mM) of pure H2O2 incubated with S. pneumoniae ΔspxB eradicated diverse S. aureus strains, suggesting that S. pneumoniae bacteria may facilitate conversion of H2O2 to a hydroxyl radical (·OH). Accordingly, S. aureus killing was completely blocked by incubation with scavengers of ·OH radicals, dimethyl sulfoxide (Me2SO), thiourea, or sodium salicylate. The ·OH was detected in S. pneumoniae cells by spin trapping and electron paramagnetic resonance. Therefore, S. pneumoniae produces H2O2, which is rapidly converted to a more potent oxidant, hydroxyl radicals, to rapidly intoxicate S. aureus strains. IMPORTANCE Streptococcus pneumoniae strains produce hydrogen peroxide (H2O2) to kill bacteria in the upper airways, including pathogenic Staphylococcus aureus strains. The targets of S. pneumoniae-produced H2O2 have not been discovered, in part because of a lack of knowledge about the underlying molecular mechanism. We demonstrated that an increased density of S. pneumoniae kills S. aureus by means of H2O2 produced by two enzymes, SpxB and LctO. We discovered that SpxB/LctO-produced H2O2 is converted into a hydroxyl radical (·OH) that rapidly intoxicates and kills S. aureus. We successfully inhibited the toxicity of ·OH with three different scavengers and detected ·OH in the supernatant. The target(s) of the hydroxyl radicals represents a new alternative for the development of antimicrobials against S. aureus infections.

scholarly journals In Vitro and In Vivo Activities of DA-7867, a New Oxazolidinone, against Aerobic Gram-Positive Bacteria

2005 ◽  
Vol 49 (6) ◽  
pp. 2498-2500 ◽  
Author(s):  
Eun Jeong Yoon ◽  
Yeong Woo Jo ◽  
Sung Hak Choi ◽  
Tae Ho Lee ◽  
Jae Keol Rhee ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Streptococcus Pneumoniae ◽  
Gram Positive ◽  
Methicillin Resistant ◽  
Gram Positive Bacteria ◽  
Vancomycin Resistant Enterococci ◽  
Infection Models ◽  
Vancomycin Resistant

ABSTRACT In vitro and in vivo activities of DA-7867 were assessed against methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, and penicillin-resistant Streptococcus pneumoniae. All isolates were inhibited by DA-7867 at ≤0.78 μg/ml, a four-times-lower concentration than that of inhibition by linezolid. For murine infection models, DA-7867 also exhibited greater efficacy than linezolid against all isolates tested.

scholarly journals Analysis of Staphylococcus aureus transcriptome in pediatric soft tissue abscesses and comparison to murine infections

2021 ◽  
Author(s):  
K Moffitt ◽  
E Cheung ◽  
T Yeung ◽  
C Stamoulis ◽  
R Malley
Keyword(s):  
Staphylococcus Aureus ◽  
Soft Tissue ◽  
Ex Vivo ◽  
Human Infection ◽  
Nucleic Acid Amplification ◽  
Clinical Strain ◽  
Nasal Colonization ◽  
Abscess Drainage ◽  
Mrna Transcripts

A comprehensive understanding of how Staphylococcus aureus adapts to cause infections in humans can inform development of diagnostic, therapeutic, and preventive approaches. Expression analysis of clinical strain libraries depicts in vitro conditions that differ from those in human infection, but low bacterial burden and the requirement for reverse transcription or nucleic acid amplification complicate such analyses of bacteria causing human infection. We developed methods to evaluate the mRNA transcript signature of S. aureus in pediatric skin and soft tissue (SSTI) infections directly ex vivo. Abscess drainage from 47 healthy pediatric patients undergoing drainage of a soft tissue infection was collected, and RNA was extracted from samples from patients with microbiologically confirmed S. aureus abscesses (42% due to methicillin-resistant S. aureus, MRSA). Using the Nanostring platform and primers targeting S. aureus mRNA transcripts encoding surface-expressed or secreted proteins, we measured direct counts of 188 S. aureus mRNA transcripts in abscess drainage. We further evaluated this mRNA signature in murine models of S. aureus SSTI and nasal colonization where the kinetics of the transcriptome could be determined. Heat maps of the S. aureus mRNA signatures from pediatric abscesses demonstrated consistent per target expression across patients. While there was significant overlap with the profiles from murine SSTI and nasal colonization, important differences were noted, which can inform efforts to develop therapeutic and vaccine approaches.

scholarly journals ANTIMICROBIAL ACTIVITY STUDY OF NEW QUINAZOLIN-4(3H)-ONES AGAINST STAPHYLOCOCCUS AUREUS AND STREPTOCOCCUS PNEUMONIAE

2021 ◽  
Vol 9 (4) ◽  
pp. 318-329
Author(s):  
M. A. Samotrueva ◽  
A. A. Ozerov ◽  
A. A. Starikova ◽  
N. M. Gabitova ◽  
D. V. Merezhkina ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Antimicrobial Activity ◽  
Streptococcus Pneumoniae ◽  
Active Sites ◽  
Wide Spectrum ◽  
Experimental Studies ◽  
Amide Group ◽  
Pharmacological Effect ◽  
Dilution Method

Quinazolin-4(3H)-one derivatives exhibiting a wide spectrum of a pharmacological activity, represent a promising class of substances used to obtain antibacterial agents, which is especially important in the context of the emergence of pathogenic microorganisms’ resistance to drugs used in medicine. It has been proved that compounds having a naphthyl radical in the molecule, as well as an amide group bound to the benzene ring as quinazolinone substituents, are characterized by a pronounced antimicrobial activity against Staphylococcus aureus and Streptococcus pneumoniae.The aim of the research is a primary microbiological screening of the in vitro antimicrobial activity of new quinazolin-4(3H)-one derivatives against Staphylococcus aureus and Streptococcus pneumoniae, as well as the assessment of the relationship between the pharmacological effect and the structural transformation of the substance molecule, lipophilicity and the possibility of forming resistance to them.Materials and methods. The experimental studies have been carried out using well-known nosocomial pathogens of infectious and inflammatory diseases Staphylococcus aureus and Streptococcus pneumoniae by a serial dilution method.Results. A compound containing a naphthyl radical in its structure, which contributes to an increase in the hydrophobicity of the substance and its solubility in the membrane of a bacterial cell, has a bacteriostatic effect against both Staphylococcus aureus and Streptococcus pneumoniae. A similar pharmacological effect is exhibited by a derivative with an amide group as a substituent of the quinazolinone nucleus linked to a phenyl radical, which probably contributes to an increase in the degree of binding to active sites of enzymes involved in the DNA replication, and protein synthesis. Obviously, the increased lipophilicity, which promotes better binding to the efflux protein, cannot serve as objective characteristics of the emergence possibility of the pathogen’s resistance to this substance.Conclusion. Among the synthesized compounds, the leading substances that exhibit an antimicrobial activity against Staphylococcus aureus and Streptococcus pneumonia, have been identified. The assessment of the chemical structure made it possible to substantiate their pharmacological action and draw conclusions about the possibility of developing resistance to it in microbial cells.

Evaluation of a Sporicidal Peracetic Acid/Hydrogen Peroxide–Based Daily Disinfectant Cleaner

2014 ◽  
Vol 35 (11) ◽  
pp. 1414-1416 ◽  
Author(s):  
Abhishek Deshpande ◽  
Thriveen S. C. Mana ◽  
Jennifer L. Cadnum ◽  
Annette C. Jencson ◽  
Brett Sitzlar ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Staphylococcus Aureus ◽  
Clostridium Difficile ◽  
Sodium Hypochlorite ◽  
Peracetic Acid ◽  
Infect Control Hosp ◽  
Organic Load ◽  
Methicillin Resistant

OxyCide Daily Disinfectant Cleaner, a novel peracetic acid/hydrogen peroxide–based sporicidal disinfectant, was as effective as sodium hypochlorite for in vitro killing of Clostridium difficile spores, methicillin-resistant Staphylococcus aureus, and vancomcyin-resistant enterococci. OxyCide was minimally affected by organic load and was effective in reducing pathogen contamination in isolation roomsInfect Control Hosp Epidemiol 2014;35(11):1414–1416

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