SDS-PAGE and Gel IEF: Tool for Differentiation of Methicillin-Resistant and Methicillin-Sensitive Strains of Staphylococcus aureus

Tesařová, Marie; Horká, Marie; Moravcová, Dana; Svojanovská, Lenka; Mlynáriková, Katarína; Růžička, Filip

doi:10.1007/s00284-015-0939-y

Cited by 2 publications

(1 citation statement)

References 15 publications

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“…MRSA infections can cause mild to severe diseases, including skin lesion, toxic shock syndrome, endocarditis, osteomyelitis, and meningitis [ 2 , 3 ]. Both hospital-acquired MRSA and community-acquired MRSA have currently become the leading causes of morbidity and mortality worldwide [ 3 , 4 ]. Furthermore, MRSA can develop co-resistance to different classes of antibiotics, including fluoroquinolones, aminoglycosides, macrolides, tetracyclines, and β-lactams, known as multidrug resistant (MDR) MRSA [ 5 – 7 ].…”

Section: Introductionmentioning

confidence: 99%

Phenotypic and genotypic characterisation of multiple antibiotic-resistant Staphylococcus aureus exposed to subinhibitory levels of oxacillin and levofloxacin

Ahn

2016

BMC Microbiol

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BackgroundThe emergence and spread of multidrug resistant methicillin-resistant Staphylococcus aureus (MDR-MRSA) has serious health consequences in the presence of sub-MIC antibiotics. Therefore, this study was designed to evaluate β-lactamase activity, efflux activity, biofilm formation, and gene expression pattern in Staphylococcus aureus KACC 10778, S. aureus ATCC 15564, and S. aureus CCARM 3080 exposed to sublethal concentrations of levofloxacin and oxacillin.ResultsThe decreased MICs were observed in S. aureus KACC and S. aureus ATCC when exposed to levofloxacin and oxacillin, while and S. aureus CCARM remained resistance to streptomycin (512 μg/mL) in the presence of levofloxacin and imipenem (>512 μg/mL) in the presence of oxacillin. The considerable increase in extracellular and membrane-bound β-lactamase activities was observed in S. aureus ATCC exposed to oxacillin (>26 μmol/min/mL). The antibiotic susceptibility of all strains exposed to EPIs (CCCP and PAβN) varied depending on the classes of antibiotics. The relative expression levels of adhesion-related genes (clfA, clfB, fnbA, fnnB, and icaD), efflux-related genes (norB, norC, and qacA/B), and enterotoxin gene (sec) were increased more than 5-fold in S. aureus CCARM. The eno and qacA/B genes were highly overexpressed by more than 12- and 9-folds, respectively, in S. aureus CCARM exposed to levofloxacin. The antibiotic susceptibility, lactamase activity, biofilm-forming ability, efflux activity, and gene expression pattern varied with the intrinsic antibiotic resistance of S. aureus KACC, S. aureus ATCC, and S. aureus CCARM exposed to levofloxacin and oxacillin.ConclusionsThis study would provide useful information for better understating of combination therapy related to antibiotic resistance mechanisms and open the door for designing effective antibiotic treatment protocols to prevent excessive use of antibiotics in clinical practice.Electronic supplementary materialThe online version of this article (doi:10.1186/s12866-016-0791-7) contains supplementary material, which is available to authorized users.

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Section: Introductionmentioning

confidence: 99%

Phenotypic and genotypic characterisation of multiple antibiotic-resistant Staphylococcus aureus exposed to subinhibitory levels of oxacillin and levofloxacin

Ahn

2016

BMC Microbiol

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Evaluation of the mechanistic basis for the antibacterial activity of ursolic acid against Staphylococcus aureus

Liu,

Qin,

Cheng

et al. 2024

Front. Microbiol.

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The antibiotics are generally regarded as the first choice approach to treat dairy mastitis, targeting the public health problems associated with the food safety and the emergence of antibioticresistant bacteria. The objective of the study was to evaluate the antibacterial efficacy of ursolic acid (UA) when used to treat Staphylococcus aureus and other isolates associated with bovine mastitis and to clarify the mechanistic basis for these effects. The bacteriostatic properties of UA extracted from Rosmarinus officinalis L. at four different purity levels were assessed by calculating minimum inhibitory concentration (MIC) values, while the synergistic effects of combining 98% UA with antibiotics were evaluated by measuring the fractional inhibitory concentration index (FICI). Changes in biofilm formation and the growth curves of the clinical isolates were assessed to clarify the bacteriostatic effect of UA. Furthermore, the cell wall integrity, protein synthesis, and reactive oxygen species (ROS) production were assessed to determine the antibacterial mechanism of UA treatment. Ultimately, UA was revealed to exhibit robust activity against Gram-positive bacteria including S. aureus (ATCC 25923), Streptococcus dysgalactiae (ATCC27957), Streptococcus agalactiae (ATCC13813), Enterococcus faecalis (ATCC29212), and Streptococcus mutans (ATCC25175). However, it did not affect Escherichia coli (ATCC 25922). The MIC values of UA preparations that were 98, 50, 30, and 10% pure against S. aureus were 39, 312, 625, and 625 μg/mL, respectively, whereas the corresponding MIC for E. coli was >5,000 μg/mL. The minimum bactericidal concentrations of 98% UA when used to treat three clinical S. aureus isolates (S4, S5, and S6) were 78, 78, and 156 μg/mL, respectively. Levels of biofilm formation for clinical S. aureus isolates decreased with increasing 98% UA concentrations. Above the MIC dose, UA treatment resulted in the dissolution of bacterial cell walls and membranes, with cells becoming irregularly shaped and exhibiting markedly impaired intracellular protein synthesis. S. aureus treated with 98% UA was able to rapidly promote intracellular ROS biogenesis. Together, these data highlight the promising utility of UA as a compound that can be used together with other antibiotics for the treatment of infections caused by S. aureus.

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SDS-PAGE and Gel IEF: Tool for Differentiation of Methicillin-Resistant and Methicillin-Sensitive Strains of Staphylococcus aureus

Cited by 2 publications

References 15 publications

Phenotypic and genotypic characterisation of multiple antibiotic-resistant Staphylococcus aureus exposed to subinhibitory levels of oxacillin and levofloxacin

Phenotypic and genotypic characterisation of multiple antibiotic-resistant Staphylococcus aureus exposed to subinhibitory levels of oxacillin and levofloxacin

Evaluation of the mechanistic basis for the antibacterial activity of ursolic acid against Staphylococcus aureus

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