scholarly journals Prevalence of Accessory Gene Regulator Specificity Groups among Methicillin Resistant Staphylococcus aureus Isolated from Iraqi Hospital Patients

2016 ◽  
Vol 5 (7) ◽  
pp. 321-328 ◽  
Author(s):  
Ali J. Saleem ◽  
Munim R. Ali ◽  
Nizar E. Nasser
Keyword(s):  
Staphylococcus Aureus ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Accessory Gene ◽  
Methicillin Resistant ◽  
Accessory Gene Regulator ◽  
Hospital Patients

scholarly journals Bisdemethoxycurcumin Reduces Methicillin-Resistant Staphylococcus aureus Expression of Virulence-Related Exoproteins and Inhibits the Biofilm Formation

Toxins ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 804
Author(s):  
Shu Wang ◽  
Ok-Hwa Kang ◽  
Dong-Yeul Kwon
Keyword(s):  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Mrna Level ◽  
Accessory Gene ◽  
Biofilm Inhibition ◽  
Methicillin Resistant ◽  
Accessory Gene Regulator ◽  
Release Assay ◽  
Necrosis Factor

Methicillin-resistant Staphylococcus aureus (MRSA) is a major pathogen of nosocomial infection, which is resistant to most antibiotics. Presently, anti-virulence therapy and anti-biofilm therapy are considered to be promising alternatives. In the current work, we investigated the influence of bisdemethoxycurcumin (BDMC) on the virulence-related exoproteins and the biofilm formation using a reference strain and clinic isolated strains. Western blotting, quantitative RT-PCR, and tumor necrosis factor (TNF) release assay were performed to assess the efficacy of BDMC in reducing the expression of Staphylococcus enterotoxin-related exoproteins (enterotoxin A, enterotoxin B) and α-toxin in MRSA. The anti-biofilm activity of BDMC was evaluated through a biofilm inhibition assay. The study suggests that sub-inhibitory concentrations of BDMC significantly inhibited the expression of sea, seb, and hla at the mRNA level in MRSA. Moreover, the expression of virulence-related exoproteins was significantly decreased by down-regulating accessory gene regulator agr, and the inhibition of biofilms formation was demonstrated by BDMC at sub-inhibitory concentrations. Consequently, the study suggests that BDMC may be a potential natural antibacterial agent to release the pressure brought by antibiotic resistance.

scholarly journals Microbiological and Genotypic Analysis of Methicillin-Resistant Staphylococcus aureus Bacteremia

2008 ◽  
Vol 52 (9) ◽  
pp. 3441-3443 ◽  
Author(s):  
Carlo McCalla ◽  
Davida S. Smyth ◽  
D. Ashley Robinson ◽  
Judith Steenbergen ◽  
Steven A. Luperchio ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Clinical Study ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Accessory Gene ◽  
Methicillin Resistant ◽  
Accessory Gene Regulator ◽  
Staphylococcus Aureus Bacteremia ◽  
Genotypic Analysis ◽  
Vancomycin Mics ◽  
Vancomycin Treatment

ABSTRACT In a recent landmark trial of bacteremia caused by methicillin-resistant Staphylococcus aureus (MRSA) isolates, vancomycin MICs were ≥1 μg/ml for only 16% of the isolates, and accessory gene regulator (agr) function as measured by delta-hemolysin activity was absent or reduced in only 28.1% of the isolates. This clinical study did not capture a population of MRSA isolates predictive of vancomycin treatment failure.

scholarly journals Bacterial Targets of Antibiotics in Methicillin-Resistant Staphylococcus aureus

Antibiotics ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 398
Author(s):  
Harshad Lade ◽  
Jae-Seok Kim
Keyword(s):  
Staphylococcus Aureus ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Teichoic Acid ◽  
Acid Synthesis ◽  
Accessory Gene ◽  
Methicillin Resistant ◽  
Accessory Gene Regulator ◽  
Healthcare Settings ◽  
Lipid Ii ◽  
Novel Therapeutic Strategies

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most prevalent bacterial pathogens and continues to be a leading cause of morbidity and mortality worldwide. MRSA is a commensal bacterium in humans and is transmitted in both community and healthcare settings. Successful treatment remains a challenge, and a search for new targets of antibiotics is required to ensure that MRSA infections can be effectively treated in the future. Most antibiotics in clinical use selectively target one or more biochemical processes essential for S. aureus viability, e.g., cell wall synthesis, protein synthesis (translation), DNA replication, RNA synthesis (transcription), or metabolic processes, such as folic acid synthesis. In this review, we briefly describe the mechanism of action of antibiotics from different classes and discuss insights into the well-established primary targets in S. aureus. Further, several components of bacterial cellular processes, such as teichoic acid, aminoacyl-tRNA synthetases, the lipid II cycle, auxiliary factors of β-lactam resistance, two-component systems, and the accessory gene regulator quorum sensing system, are discussed as promising targets for novel antibiotics. A greater molecular understanding of the bacterial targets of antibiotics has the potential to reveal novel therapeutic strategies or identify agents against antibiotic-resistant pathogens.

Exploring the Role of Piperacillin and Tazobactam in Combination with Vancomycin against Methicillin-Resistant Staphylococcus aureus

Chemotherapy ◽  
2019 ◽  
Vol 64 (5-6) ◽  
pp. 233-237
Author(s):  
Thomas J. Dilworth ◽  
Daniel Sanchez ◽  
Beverly Anderson ◽  
Haedi DeAngelis ◽  
Renée-Claude Mercier
Keyword(s):  
Staphylococcus Aureus ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Accessory Gene ◽  
Methicillin Resistant ◽  
Accessory Gene Regulator ◽  
Antibiotic Susceptibilities ◽  
Strain Type ◽  
Time Kill

Previous studies have demonstrated synergy between piperacillin (PIP)-tazobactam (TAZ) (TZP) and vancomycin (VAN) against methicillin-resistant Staphylococcus aureus (MRSA). However, it is unknown whether PIP and/or TAZ synergizes with VAN against MRSA. We sought to determine whether PIP and/or TAZ synergizes with VAN against MRSA in vitro. The activity of PIP and/or TAZ with and without VAN (1/2 the minimum inhibitory concentration) was tested against 5 clinical MRSA isolates using a 24-h time-kill methodology. Antibiotic susceptibilities, accessory gene regulator (agr) operon functionality, and US strain type were also determined for the isolates. The combination of VAN and TZP was bactericidal against 3/5 isolates and synergistic against 4/5 isolates tested. Neither PIP nor TAZ alone combined with VAN demonstrated a significant reduction in bacterial growth. The combination of TZP and VAN was less active against the lone isolate with agr dysfunction. In summation, the combination of VAN with both PIP and TAZ was required for synergy against MRSA. This antibiotic combination may not be effective against unique MRSA strain types.

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