In Vitro Activity of Ceftaroline against Clinical Isolates of Streptococcus pneumoniae Recovered in 43 U.S. Medical Centers during 2010-2011

Abstract

The in vitro activity of ceftaroline, a recently introduced parenteral cephalosporin, was assessed versus 1,750 isolates of Streptococcus pneumoniae recovered from patients with a variety of pneumococcal infections in 43 U.S. medical centers during 2010-2011. Using a breakpoint of <0.5 g/ml for susceptibility, all of the isolates were found to be susceptible to ceftaroline. Ceftaroline MICs were consistently 16-fold lower than ceftriaxone MICs. Among the isolates characterized in this investigation, 38.9% were found to be nonsusceptible to penicillin (oral penicillin breakpoints) and 9.1% were nonsusceptible to ceftriaxone (nonmeningitis breakpoints).

Changes in Pneumococcal Serotypes and Antimicrobial Resistance after Introduction of the 13-Valent Conjugate Vaccine in the United States

“…Our data confirms the potent activity of ceftaroline against ceftriaxone-resistant and MDR S. pneumoniae phenotypes. The ceftaroline MIC distribution reported here is similar to that described in earlier reports (12,19).…”

“…Penicillin-resistant S. pneumoniae (PRSP) was defined as an isolate with a penicillin MIC of Ն2 g/ml. The 2012-13 surveillance data were compared to data derived from the same surveillance network collected during 2008-09 and 2010-11 (7,12). Statistical significance was assessed using the two-tailed Fisher exact test.…”

Pneumococcal Serotypes before and after Introduction of Conjugate Vaccines, United States, 1999–20111

“…Serotyping was repeated on serogroup 6 isolates from 1999–2000 (penicillin-resistant isolates) and from 2004–2005 to detect 6C and 6D in collections for which serotyping results were published ( 20 , 21 ). Susceptibility data have been reported for the 1999–2000, 2004–2005, and 2010–2011 surveillance periods ( 4 , 21 , 22 ). The statistical significance of differences in serotype distribution for time periods, age groups, and specimen sources was assessed by using the Fisher exact test (2-tailed).…”

Evaluation of Pneumococcal Serotyping by Multiplex PCR and Quellung Reactions

“…The purpose of this study was to evaluate the utility of PCRbased serotyping as part of a longitudinal pneumococcal surveillance program in the United States with centralized laboratory testing (10)(11)(12). A sequential PCR/Quellung reaction serotyping algorithm was employed with initial detection of common serotypes by one multiplex PCR followed by Quellung reaction analysis to assign remaining serotypes.…”

“…Serotyping by the Quellung reaction using antisera from the Statens Serum Institut (Copenhagen, Denmark) was performed on a collection of 1,750 pneumococcal isolates obtained from different patients in 43 U.S. medical centers during October 2010 through March 2011 (11,12 First, all isolates were screened by multiplex PCR using 5 primer sets, each targeting one of the common serotypes (3, 6A/ B/C/D, 7F, 19A, and 22F/22A) and electrophoresis detection methods adapted from the CDC Streptococcus laboratory (http: //www.cdc.gov/ncidod/biotech/strep/pcr.htm). This approach requires that the product sizes included in the multiplex reaction are different enough to be easily distinguished.…”