In vitro development and stability of tolerance to cloxacillin and vancomycin inStaphylococcus aureus

Voorn, G. Paul; Thompson, J.; Goessens, W. H. F.; Schmal-Bauer, W. C.; Broeders, P. H. M.; Michel, M. F.

doi:10.1007/bf02276057

Cited by 10 publications

(6 citation statements)

References 33 publications

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“…These newer agents are generally bacteriostatic against MRSA. However, tolerance to vancomycin among clinical S. aureus isolates has been previously described (15,21,24,30,31). We wanted to investigate whether decreased killing by vancomycin in vitro translated to any clinical effect of treatment.…”

Section: Discussionmentioning

confidence: 99%

Relationship of MIC and Bactericidal Activity to Efficacy of Vancomycin for Treatment of Methicillin-Resistant Staphylococcus aureus Bacteremia

et al. 2004

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We attempted to find a relationship between the microbiological properties of bloodstream isolates of methicillin-resistant Staphylococcus aureus (MRSA) and the efficacy of vancomycin in the treatment of bacteremia. Vancomycin susceptibility testing was performed, and bactericidal activity was determined for 30 isolates from 30 different patients with MRSA bacteremia for whom clinical and microbiological outcome data were available. The majority of these patients had been previously enrolled in multicenter prospective studies of MRSA bacteremia refractory to conventional vancomycin therapy. Logistic regression found a statistically significant relationship between treatment success with vancomycin and decreases in both vancomycin MICs (<0.5 g/ml versus 1.0 to 2.0 g/ml; P ‫؍‬ 0.02) and degree of killing (reduction in 1og 10 CFU/milliliter) by vancomycin over 72 h of incubation in vitro (P ‫؍‬ 0.03). For MRSA isolates with vancomycin MICs < 0.5 g/ml, vancomycin was 55.6% successful in the treatment of bacteremia whereas vancomycin was only 9.5% effective in cases in which vancomycin MICs for MRSA were 1 to 2 g/ml.

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Section: Discussionmentioning

confidence: 99%

Relationship of MIC and Bactericidal Activity to Efficacy of Vancomycin for Treatment of Methicillin-Resistant Staphylococcus aureus Bacteremia

et al. 2004

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“…The bacteria used in the present study were as follows: S. aureus 42D, an original clinical isolate strain kept in the laboratory for several years; S. aureus 5558, a strain isolated from a patient with BE; S. epidermidis ATCC 149900; and S. sanguis NCTC 7864. These bacteria have been used in our other studies, and features of their interaction with and invasion and activation of ECs have been described elsewhere [13,14,17,19,21,38]. Bacteria suspensions were stored at Ϫ70ЊC and were thawed before use.…”

Section: Methodsmentioning

confidence: 99%

Monocytes Maintain Tissue Factor Activity after Cytolysis of Bacteria‐Infected Endothelial Cells in an In Vitro Model of Bacterial Endocarditis

Veltrop

Beekhuizen

2002

J INFECT DIS

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Intravascular infection with Staphylococcus aureus, Staphylococcus epidermidis, or Streptococcus sanguis can initiate fibrin formation on endocardial tissue, causing bacterial endocarditis. The ability of these bacteria to injure intact endothelial cells (ECs) and to aggravate tissue factor (TF)-dependent coagulation in the presence of blood leukocytes was investigated. Cytolysis of ECs occurred after infection with S. aureus and, with membrane-bound monocytes or granulocytes present, also after infection with S. sanguis or S. epidermidis. Monocytes that subsequently bound to the resultant bacteria-infected subcellular EC matrix (ECM) elicited TF mRNA, TF antigen, and TF activity (TFA). This was most pronounced in ECM prepared after the cytolysis of ECs by infection with S. aureus or S. epidermidis. We demonstrate that monocytes continue and intensify fibrin formation after lysis of bacteria-infected ECs, which suggests that, during the course of intravascular infection, early fibrin formation shifts from being mediated by EC-derived TFA to being mediated by TFA of monocytes bound to bacteria-infected ECM.

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“…Moreover, tolerance may emerge during prolonged Van therapy. It has been reported that Van tolerance of MRSA can be acquired or lost in vitro during repeated subculture in the presence and absence of the antibiotic respectively (Voorn et al ., 1994; Sakoulas et al ., 2006; Sieradzki and Tomasz, 2006). The mechanism of Van tolerance in S. aureus (both clinical isolates and laboratory mutants) is often associated with the ability to produce a biofilm or a change in autolysin activity, but other mechanisms may be present in tolerant strains from clinical sources (May et al ., 1998; Sakoulas et al ., 2006; Mlynarcyk et al ., 2009).…”

Section: Van Tolerance In Staphylococcusmentioning

confidence: 99%

Vancomycin tolerance in Gram-positive cocci

Moscoso

Domenech

Garcı́a

2011

Environmental Microbiology Reports

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Vancomycin, a glycopeptide antimicrobial agent, represents the last line of defence against a wide range of multi-resistant Gram-positive pathogens such as enterococci, staphylococci and streptococci. However, vancomycin-resistant enterococci and staphylococci, along with vancomycin-tolerant clinical isolates, are compromising the therapeutic efficacy of vancomycin. It is conceivable that tolerance may emerge during prolonged vancomycin use. It has not been until recently, however, that the molecular basis of this tolerance began to be understood. Superoxide anions might be involved in the bactericidal activity of vancomycin in enterococci, and recent evidence suggests that the stringent response is partly responsible for vancomycin tolerance in Enterococcus faecalis. The mechanism of vancomycin tolerance in Staphylococcus aureus and Streptococcus pneumoniae is sometimes associated with a reduction of autolysin activity. Vancomycin tolerance in S. aureus and S. pneumoniae also appears to be somehow related with the two-component regulatory systems linked to cell envelope stress, although the precise molecular regulatory pathways remain poorly defined.

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In vitro development and stability of tolerance to cloxacillin and vancomycin inStaphylococcus aureus

Cited by 10 publications

References 33 publications

Relationship of MIC and Bactericidal Activity to Efficacy of Vancomycin for Treatment of Methicillin-Resistant Staphylococcus aureus Bacteremia

Relationship of MIC and Bactericidal Activity to Efficacy of Vancomycin for Treatment of Methicillin-Resistant Staphylococcus aureus Bacteremia

Monocytes Maintain Tissue Factor Activity after Cytolysis of Bacteria‐Infected Endothelial Cells in an In Vitro Model of Bacterial Endocarditis

Vancomycin tolerance in Gram-positive cocci

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