Cephalosporin susceptibility of methicillin-resistant, coagulase-negative staphylococci

Menzies, R E; Cornere, B.; MacCulloch, D

doi:10.1128/aac.31.1.42

Cited by 22 publications

(12 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Yet, in some studies (11) cefamandole has been found to be effective clinically for a wide range of infections (excluding endocarditis) caused by methicillin-resistant staphylococci. Our data support the results of the latter studies, although cross-resistance between methicillin and cephalosporin agents with staphylococci (1,18) …”

Section: Methodssupporting

confidence: 83%

Activity of LY146032 compared with that of methicillin, cefazolin, cefamandole, cefuroxime, ciprofloxacin, and vancomycin against staphylococci as determined by kill-kinetic studies

Stratton¹,

Liu²,

Weeks³

1987

Antimicrob Agents Chemother

View full text Add to dashboard Cite

Kill-kinetic methods were used to provide data on the bactericidal activity of subinhibitory (0.5x MIC), inhibitory (ix MIC), and suprainhibitory (4x MIC) concentrations of LY146032 against methicillinsusceptible and -resistant Staphylococcus aureus and Staphylococcus epidermidis. These bactericidal activities were compared with those of methicillin, cefazolin, cefamandole, cefuroxime, ciprofloxacin, and vancomycin. LY146032 was among the most active of the antistaphylococcal agents tested, as determined by broth microdilution methods, with all strains being inhibited at concentrations of '1 ,ug/ml. Time kill-kinetic studies demonstrated that at 4x MIC, LY146032 was rapidly bactericidal against all strains of staphylococci. Our data show that LY146032 has significant bactericidal activity against staphylococci in comparison with other antistaphylococcal agents. Further evaluation of LY146032 against serious staphylococcal infections is warranted.LY146032 is a cyclic polypeptide which has been shown by standard broth dilution techniques to be bactericidal against staphylococci at concentrations near the MIC (6-8, 14, 25). This suggests that LY146032 may be useful clinically as a single agent against serious staphylococcal infectons, including endocarditis. To provide additional data on the bactericidal activity of LY146032 in comparison with those of methicillin, cefazolin, cefamandole, cefuroxime, ciprofloxacin, and vancomycin, kill-kinetic methods were used in this study to compare the subinhibitory (0.5x MIC), inhibitory (lx MIC), and suprainhibitory (4x MIC) concentrations of these agents. MATERIALS AND METHODSMicroorganisms. One hundred isolates of staphylococci obtained from blood were studied. Included in these isolates were 25 strains of methicillin-susceptible (MIC, .2 jig/ml) S. aureus, 25 strains of methicillin-resistant (MIC, -16 ptg/ml) S. aureus, 25 strains of methicillin-susceptible (MIC, .2 ,ug/ml) S. epidermidis, and 25 strains of methicillin-resistant (MIC, .16 ,ug/ml) S. epidermidis. Identification of S. aureus was performed by a previously established methodology (13) which included colony morphology, Gram stain characteristics, ability to coagulate rabbit serum, and the presence of heat-stable DNase activity. Identification of S. epidermidis was done by using criteria and methods established by Kloos and Jorgensen (13). Methicillin-susceptible and -resistant strains were determined by a reference broth microdilution method with Mueller-Hinton broth containing 2% NaCl (20,24 ciprofloxacin, Miles Pharmaceuticals, West Haven, Conn. Antimicrobial stock solutions were prepared according to the instructions of the manufacturers and stored at -70°C until use. Final concentrations were prepared on the day they were used.Media. Mueller-Hinton broth (BBL Microbiology Systems, Cockeysville, Md.) was used in both the broth microdilution method and the kill-kinetic method and was supplemented with 2% NaCl for the testing of beta-lactam agents (20,24) and with physiologic concentrations of calcium and mag...

show abstract

Section: Methodssupporting

confidence: 83%

Activity of LY146032 compared with that of methicillin, cefazolin, cefamandole, cefuroxime, ciprofloxacin, and vancomycin against staphylococci as determined by kill-kinetic studies

Stratton¹,

Liu²,

Weeks³

1987

Antimicrob Agents Chemother

View full text Add to dashboard Cite

show abstract

“…In contrast, cefamandole has not been consistently effective against methicillin-resistant staphylococci either in experimental models of infection (6) or in clinical studies (2,4). These discrepant results may be due to differences in degrees of methicillin resistance among strains of staphylococci (7). Recently Hartman and Tomasz identified three phenotypes of methicillin-resistant S. aureus: homogeneous, heterogeneous, and thermosensitive heterogeneous (5).…”

mentioning

confidence: 97%

Relationship between cefamandole and cefuroxime activity against oxacillin-resistant Staphylococcus epidermidis and oxacillin resistance phenotype

Woods

Knapp

Washington

1987

Antimicrob Agents Chemother

View full text Add to dashboard Cite

The activity of cefamandole and cefuroxime against oxacillin-resistant Staphylococcus epidermidis was studied in vitro to determine whether there was any relationship between oxacillin resistance phenotypes and cephalosporin activity. Oxacillin resistance phenotypes were determined by efficiency-of-plating studies on Mueller-Hinton agar containing oxacillin, with and without NaCl, and incubated at 30 and 35°C. On the basis of MIC and MBC determinations, cefamandole was more active than cefuroxime against oxacillin-resistant S. epidermidis. Although temperature had minimal effect on the activity of either cefamandole or cefuroxime, NaCl significantly decreased the activity of cefuroxime but not of cefamandole. Neither cephalosporin consistently produced -99.9% bactericidal activity within 24 h in timed killing-curve studies. No consistent relationship was observed between cefamandole or cefuroxime activity and oxacillin resistance phenotype.According to current standards for antimicrobial susceptibility tests of the National Committee for Clinical Laboratory Standards, all methicillin-resistant staphylococci should be considered resistant to cephalosporins (8). In recent studies, however, cefamandole has been shown to be active in vitro against methicillin-resistant Staphylococcus aureus and Staphylococcus epidermidis (3, 13). Furthermore, when compared with cefazolin for prophylaxis in cardiac surgery patients, both cefamandole (M. R. Petracek, A. B. Kaiser, J. W. Lea, D. S. Kernodle, and A. C. Roach, Clin. Res. 35:21a, 1987) and cefuroxime have been associated with significantly fewer postoperative staphylococcal infections (11). In contrast, cefamandole has not been consistently effective against methicillin-resistant staphylococci either in experimental models of infection (6) or in clinical studies (2, 4). These discrepant results may be due to differences in degrees of methicillin resistance among strains of staphylococci (7). Recently Hartman and Tomasz identified three phenotypes of methicillin-resistant S. aureus: homogeneous, heterogeneous, and thermosensitive heterogeneous (5). Studies identifying phenotypes of methicillin-resistant S. epidermidis, however, have not been done. The objectives of our study were first to determine whether methicillin (oxacillin) resistance phenotypes similar to those identified for methicillin-resistant S. aureus exist among oxacillinresistant S. epidermidis and second to determine whether the resistance phenotype relates to the activity of cefamandole and cefuroxime against oxacillin-resistant S. epidermidis. MATERIALS AND METHODSOrganisms. Blood culture isolates, identified specifically as S. epidermidis, were taken from 40 patients. Each isolate was initially characterized as being oxacillin resistant by disk diffusion susceptibility testing (16). * Corresponding author. Antimicrobial agents and susceptibility testing. Oxacillin was obtained from Sigma Chemical Co., St. Louis, Mo.; cefamandole was obtained from Eli Lilly & Co., Indianapolis, Ind.; and cefuroxime was ...

show abstract

“…Cross-resistance for methicillin and some cephalosporins has been demonstrated (Hansen-Nord et al, 1988;Menzies et al, 1987), with administration of cephalosporins increasing the acquisition of nosocomial MRSA three-fold (Asensio et al, 1996). Similarly, tetracycline resistance may be caused by one of several genes, one of which, tetK, is carried by a plasmid (pT181) that is inserted into SCCmecIII (Ito et al, 2003).…”

Section: B Environmental Reservoirs Of Mrsamentioning

confidence: 99%

Antibiotic Resistance in the Environment, with Particular Reference to MRSA

Gaze

O’Neill

Wellington

et al. 2008

Advances in Applied Microbiology

View full text Add to dashboard Cite

Cephalosporin susceptibility of methicillin-resistant, coagulase-negative staphylococci

Cited by 22 publications

References 19 publications

Activity of LY146032 compared with that of methicillin, cefazolin, cefamandole, cefuroxime, ciprofloxacin, and vancomycin against staphylococci as determined by kill-kinetic studies

Activity of LY146032 compared with that of methicillin, cefazolin, cefamandole, cefuroxime, ciprofloxacin, and vancomycin against staphylococci as determined by kill-kinetic studies

Relationship between cefamandole and cefuroxime activity against oxacillin-resistant Staphylococcus epidermidis and oxacillin resistance phenotype

Antibiotic Resistance in the Environment, with Particular Reference to MRSA

Contact Info

Product

Resources

About