scholarly journals Biofilm Formation by Staphylococcus aureus Clinical Isolates is Differentially Affected by Glucose and Sodium Chloride Supplemented Culture Media

2019 ◽  
Vol 8 (11) ◽  
pp. 1853 ◽  
Author(s):  
Harshad Lade ◽  
Joon Hyun Park ◽  
Sung Hee Chung ◽  
In Hee Kim ◽  
Jung-Min Kim ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Sodium Chloride ◽  
Biofilm Formation ◽  
Culture Media ◽  
Toxin Production ◽  
Culture Conditions ◽  
Clinical Isolates ◽  
Accessory Gene ◽  
Methicillin Resistant

Staphylococcus aureus (S. aureus) causes persistent biofilm-related infections. Biofilm formation by S. aureus is affected by the culture conditions and is associated with certain genotypic characteristics. Here, we show that glucose and sodium chloride (NaCl) supplementation of culture media, a common practice in studies of biofilms in vitro, influences both biofilm formation by 40 S. aureus clinical isolates (methicillin-resistant and methicillin-sensitive S. aureus) and causes variations in biofilm quantification. Methicillin-resistant strains formed more robust biofilms than methicillin-sensitive strains in tryptic soy broth (TSB). However, glucose supplementation in TSB greatly promoted and stabilized biofilm formation of all strains, while additional NaCl was less efficient in this respect and resulted in significant variation in biofilm measurements. In addition, we observed that the ST239-SCCmec (Staphylococcal Cassette Chromosome mec) type III lineage formed strong biofilms in TSB supplemented with glucose and NaCl. Links between biofilm formation and accessory gene regulator (agr) status, as assessed by δ-toxin production, and with mannitol fermentation were not found. Our results show that TSB supplemented with 1.0% glucose supports robust biofilm production and reproducible quantification of S. aureus biofilm formation in vitro, whereas additional NaCl results in major variations in measurements of biofilm formation.

scholarly journals In vitro activity of minocycline combined with fosfomycin against clinical isolates of methicillin-resistant Staphylococcus aureus

2011 ◽  
Vol 64 (8) ◽  
pp. 559-562 ◽  
Author(s):  
Chunguang Sun ◽  
Matthew E Falagas ◽  
Rui Wang ◽  
Drosos E Karageorgopoulos ◽  
Xuhong Yu ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Vitro Activity ◽  
Clinical Isolates ◽  
In Vitro Activity ◽  
Methicillin Resistant

scholarly journals Vancomycin In Vitro Bactericidal Activity and Its Relationship to Efficacy in Clearance of Methicillin-Resistant Staphylococcus aureus Bacteremia

2007 ◽  
Vol 51 (7) ◽  
pp. 2582-2586 ◽  
Author(s):  
Pamela A. Moise ◽  
George Sakoulas ◽  
Alan Forrest ◽  
Jerome J. Schentag
Keyword(s):  
Staphylococcus Aureus ◽  
Median Time ◽  
Bactericidal Activity ◽  
Peak Plasma ◽  
Plasma Concentrations ◽  
Accessory Gene ◽  
Vancomycin Therapy ◽  
Methicillin Resistant ◽  
Vancomycin Mics

ABSTRACT We examined the relationship between the time to clearance of methicillin-resistant Staphylococcus aureus (MRSA) bacteremia while patients were receiving vancomycin therapy and the in vitro bactericidal activity of vancomycin. Vancomycin killing assays were performed with 34 MRSA bloodstream isolates (17 accessory gene regulator group II [agr-II] and 17 non-agr-II isolates) from 34 different patients with MRSA bacteremia for whom clinical and microbiological outcomes data were available. Vancomycin doses were prospectively adjusted to achieve peak plasma concentrations of 28 to 32 μg/ml and trough concentrations of 8 to 12 μg/ml. Bactericidal assays were performed over 24 h with ∼107 to 108 CFU/ml in broth containing 16 μg/ml vancomycin. The median time to clearance of bacteremia was 6.5 days for patients with MRSA isolates demonstrating ≥2.5 reductions in log10 CFU/ml at 24 h and >10.5 days for patients with MRSA isolates demonstrating <2.5 log10 CFU/ml by 24 h (P = 0.025). The median time to clearance was significantly longer with MRSA isolates with vancomycin MICs of 2.0 μg/ml compared to that with MRSA isolates with MICs of ≤1.0 μg/ml (P = 0.019). The bacteremia caused by MRSA isolates with absent or severely reduced delta-hemolysin expression was of a longer duration of bacteremia (10 days and 6.5 days, respectively; P = 0.27) and had a decreased probability of eradication (44% and 78%, respectively; P = 0.086). We conclude that strain-specific microbiological features of MRSA, such as increased vancomycin MICs and decreased killing by vancomycin, appear to be predictive of prolonged MRSA bacteremia while patients are receiving vancomycin therapy. Prolonged bacteremia and decreased delta-hemolysin expression may also be related. Evaluation of these properties may be useful in the consideration of antimicrobial therapies that can be used as alternatives to vancomycin for the treatment of MRSA bacteremia.

Effect of vancomycin-coated tympanostomy tubes on methicillin-resistant Staphylococcus aureus biofilm formation: in vitro study

2010 ◽  
Vol 124 (6) ◽  
pp. 594-598 ◽  
Author(s):  
C H Jang ◽  
H Park ◽  
Y B Cho ◽  
C H Choi
Keyword(s):  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Silver Oxide ◽  
In Vitro Study ◽  
Bacterial Biofilm ◽  
Tube Placement ◽  
Tympanostomy Tube ◽  
Methicillin Resistant ◽  
Tympanostomy Tubes

AbstractBackground and objective:Bacterial biofilm formation has been implicated in the high incidence of persistent otorrhoea after tympanostomy tube insertion. It has been suggested that the tube material may be an important factor in the persistence of such otorrhoea. Development of methicillin-resistant Staphylococcus aureus otorrhoea after tympanostomy tube placement is a growing concern. We evaluated the effect of using vancomycin and chitosan coated tympanostomy tubes on the incidence of methicillin-resistant Staphylococcus aureus biofilm formation in vitro.Materials and methods:Three sets each of vancomycin-coated silicone tubes (n = 5), commercial silver oxide coated silicone tubes (n = 5) and uncoated tympanostomy tubes (as controls; n = 5) were compared as regards resistance to methicillin-resistant Staphylococcus aureus biofilm formation after in vitro incubation.Results:Scanning electron microscopy showed that the surfaces of the silver oxide coated tubes supported the formation of thick biofilms with crusts, comparable to the appearance of the uncoated tubes. In contrast, the surface of the vancomycin-coated tympanostomy tubes was virtually devoid of methicillin-resistant Staphylococcus aureus biofilm.Conclusion:Vancomycin-coated tympanostomy tubes resist methicillin-resistant Staphylococcus aureus biofilm formation. Pending further study, such tubes show promise in assisting the control of methicillin-resistant Staphylococcus aureus biofilm formation.

scholarly journals Evaluation of Antibiotics Active against Methicillin-Resistant Staphylococcus aureus Based on Activity in an Established Biofilm

2016 ◽  
Vol 60 (10) ◽  
pp. 5688-5694 ◽  
Author(s):  
Daniel G. Meeker ◽  
Karen E. Beenken ◽  
Weston B. Mills ◽  
Allister J. Loughran ◽  
Horace J. Spencer ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Biofilm Formation ◽  
Limit Of Detection ◽  
Relative Activity ◽  
Methicillin Resistant ◽  
Content Type ◽  
Comparable Activity ◽  
Antibiotic Delivery

ABSTRACTWe usedin vitroandin vivomodels of catheter-associated biofilm formation to compare the relative activity of antibiotics effective against methicillin-resistantStaphylococcus aureus(MRSA) in the specific context of an established biofilm. The results demonstrated that, underin vitroconditions, daptomycin and ceftaroline exhibited comparable activity relative to each other and greater activity than vancomycin, telavancin, oritavancin, dalbavancin, or tigecycline. This was true when assessed using established biofilms formed by the USA300 methicillin-resistant strain LAC and the USA200 methicillin-sensitive strain UAMS-1. Oxacillin exhibited greater activity against UAMS-1 than LAC, as would be expected, since LAC is an MRSA strain. However, the activity of oxacillin was less than that of daptomycin and ceftaroline even against UAMS-1. Among the lipoglycopeptides, telavancin exhibited the greatest overall activity. Specifically, telavancin exhibited greater activity than oritavancin or dalbavancin when tested against biofilms formed by LAC and was the only lipoglycopeptide capable of reducing the number of viable bacteria below the limit of detection. With biofilms formed by UAMS-1, telavancin and dalbavancin exhibited comparable activity relative to each other and greater activity than oritavancin. Importantly, ceftaroline was the only antibiotic that exhibited greater activity than vancomycin when testedin vivoin a murine model of catheter-associated biofilm formation. These results emphasize the need to consider antibiotics other than vancomycin, most notably, ceftaroline, for the treatment of biofilm-associatedS. aureusinfections, including by the matrix-based antibiotic delivery methods often employed for local antibiotic delivery in the treatment of these infections.

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