In Vitro Activity Of Ceftaroline And Comparative Agents Against Clinical Isolates Of Streptococcus Pneumoniae Collected From An Ongoing Canada Wide Surveillance Program: 2008 - 2011

2012 ◽  
Author(s):  
Donald E. Low ◽  
Karen Green ◽  
Allison McGeer ◽  
Sylvia Pong-Porter ◽  
Samir Patel
Keyword(s):  
Streptococcus Pneumoniae ◽  
Vitro Activity ◽  
Clinical Isolates ◽  
Surveillance Program ◽  
In Vitro Activity

scholarly journals In Vitro Evaluation of the Antimicrobial Activity of Ceftaroline against Cephalosporin-Resistant Isolates of Streptococcus pneumoniae

2008 ◽  
Vol 53 (2) ◽  
pp. 552-556 ◽  
Author(s):  
Lesley McGee ◽  
Donald Biek ◽  
Yigong Ge ◽  
Magderie Klugman ◽  
Mignon du Plessis ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Vitro Activity ◽  
Clinical Isolates ◽  
Surveillance Program ◽  
In Vitro Activity ◽  
Penicillin Binding Protein ◽  
Control And Prevention ◽  
Cephalosporin Resistance ◽  
Resistant Strains

ABSTRACT Increasing pneumococcal resistance to extended-spectrum cephalosporins warrants the search for novel agents with activity against such resistant strains. Ceftaroline, a parenteral cephalosporin currently in phase 3 clinical development, has demonstrated potent in vitro activity against resistant gram-positive organisms, including penicillin-resistant Streptococcus pneumoniae. In this study, the activity of ceftaroline was evaluated against highly cefotaxime-resistant isolates of pneumococci from the Active Bacterial Core surveillance program of the Centers for Disease Control and Prevention and against laboratory-derived cephalosporin-resistant mutants of S. pneumoniae. The MICs of ceftaroline and comparators were determined by broth microdilution. In total, 120 U.S. isolates of cefotaxime-resistant (MIC ≥ 4 μg/ml) S. pneumoniae were tested along with 18 laboratory-derived R6 strains with known penicillin-binding protein (PBP) mutations. Clinical isolates were characterized by multilocus sequence typing, and the DNAs of selected isolates were sequenced to identify mutations affecting pbp genes. Ceftaroline (MIC90 = 0.5 μg/ml) had greater in vitro activity than penicillin, cefotaxime, or ceftriaxone (MIC90 = 8 μg/ml for all comparators) against the set of highly cephalosporin-resistant clinical isolates of S. pneumoniae. Ceftaroline was also more active against the defined R6 PBP mutant strains, which suggests that ceftaroline can overcome common mechanisms of PBP-mediated cephalosporin resistance. These data indicate that ceftaroline has significant potency against S. pneumoniae strains resistant to existing parenteral cephalosporins and support its continued development for the treatment of infections caused by resistant S. pneumoniae strains.

scholarly journals Determining Linezolid’s Baseline In Vitro Activity in Canada Using Gram-Positive Clinical Isolates Collected prior to Its National Release

2002 ◽  
Vol 46 (6) ◽  
pp. 1989-1992 ◽  
Author(s):  
James A. Karlowsky ◽  
Laurie J. Kelly ◽  
Ian A. Critchley ◽  
Mark E. Jones ◽  
Clyde Thornsberry ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Streptococcus Pneumoniae ◽  
Staphylococcus Epidermidis ◽  
Vitro Activity ◽  
Clinical Isolates ◽  
Clinical Use ◽  
In Vitro Activity ◽  
Gram Positive ◽  
Future Studies

ABSTRACT All of the isolates of Staphylococcus aureus (n = 317), Enterococcus species (n = 315), Streptococcus pneumoniae (n = 282), and Staphylococcus epidermidis (n = 176) collected at 16 Canadian microbiology laboratories from October 2000 to April 2001 were susceptible to linezolid. Future studies will determine how linezolid clinical use in Canada affects its in vitro activity.

scholarly journals In vitro activity of thiamphenicol against Haemophilus influenzae, Streptococcus pneumoniae and Streptococcus pyogenes clinical isolates

2021 ◽  
Vol 23 (1) ◽  
pp. 92-99
Author(s):  
Nataly V. Ivanchik ◽  
Мarina V. Sukhorukova ◽  
Аida N. Chagaryan ◽  
Ivan V. Trushin ◽  
Andrey V. Dekhnich ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Haemophilus Influenzae ◽  
Streptococcus Pyogenes ◽  
Vitro Activity ◽  
Clinical Isolates ◽  
In Vitro Activity ◽  
Microdilution Method ◽  
Broth Microdilution Method ◽  
Clinical Breakpoints

Objective. To determine in vitro activity of thiamphenicol and other clinically available antimicrobials against clinical isolates of Haemophilus influenzae, Streptococcus pneumoniae and Streptococcus pyogenes. Materials and Methods. We included in the study 875 clinical isolates from 20 Russian cities during 2018–2019. Among tested strains, 126 were H. influenzae, 389 – S. pneumoniae, 360 – S. pyogenes. Antimicrobial susceptibility testing was performed using broth microdilution method according to ISO 20776-1:2006. AST results were interpreted according to EUCAST v.11.0 clinical breakpoints. Results. The minimum inhibitory concentrations (MICs) of thiamphenicol did not exceed 2 mg/L for 94.4% of H. influenzae strains (MIC50 and MIC90 were 0.5 and 1 mg/L, respectively). Thiamphenicol was active against 76.9% of ampicillin-resistant H. influenzae strains (MIC of thiamphenicol < 2 mg/L). The MIC of thiamphenicol was in the range of 0.06–2 mg/L for 96.7% of S. pneumoniae strains (MIC50 and MIC90 were 0.5 and 2 mg/L, respectively). The MIC of thiamphenicol for 90.6% of S. pneumoniae strains with reduced susceptibility to penicillin (MIC of penicillin > 0.06 mg/L) did not exceed 2 mg/L. A total of 88.1% of S. pneumoniae strains resistant to erythromycin were highly susceptible to thiamphenicol (MIC < 2 mg/L). The MIC of thiamphenicol did not exceed 8 mg/L for 96.1% of S. pyogenes strains (MIC50 and MIC90 were 2 and 4 mg/L, respectively). Conclusions. Thiamphenicol was characterized by relatively high in vitro activity, comparable to that of chloramphenicol, against tested strains of H. influenzae, S. pneumoniae and S. pyogenes, including S. pneumoniae isolates with reduced susceptibility to penicillin.

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