title: Serotype distribution and antimicrobial susceptibility of USA Streptococcus pneumoniae isolates collected prior to and post introduction of 13-valent pneumococcal conjugate vaccine.
abstract: This study evaluated pneumococci cultured from blood or lower respiratory tract specimens from hospitalized patients in the USA (all age groups) during 2011-2012 (N = 1190) and compared findings with those from a similar study performed in 2008 (N = 694). Isolates were tested for susceptibility by broth microdilution and serotypes determined by cpsB sequencing, supplemented with multiplex PCR and capsular swelling assays. Relative percentages of 7-valent pneumococcal conjugate vaccine (PCV7) types were 6.3 and 4.9% in 2008 and 2011-2012, respectively, and the most common PCV7 serotypes (19F and 6B) comprised only 3.7% and 4.0% of all isolates from both periods, respectively. Thirteen-valent pneumococcal conjugate vaccine (PCV13) serotypes represented 42.9% of isolates in 2008 and 30.1% in the second period, and this decrease was driven by 19A and 7F. Non-PCV13 serogroups/serotypes 23A, 15B/15C, 7C, 8, and 31 increased. Penicillin non-susceptibility rates were 9.6-10.0% and 38.9-42.7% when applying the parenteral (i.e. ≥ 4 μg/mL) and oral breakpoints (i.e. ≥ 0.12 μg/mL), respectively. Ceftaroline was the most potent agent tested based on MIC50 and MIC90 values (≤ 0.015 and 0.12 μg/mL, respectively) for both time periods.
authors: JMI Laboratories, North Liberty, IA, USA. Electronic address: rodrigo-mendes@jmilabs.com.
authors: Rodrigo E
authors: RE
authors: Mendes
authors: JMI Laboratories, North Liberty, IA, USA.
authors: Andrew J
authors: AJ
authors: Costello
authors: Case Western Reserve University and University Hospitals, Case Medical Center, Cleveland, OH, USA.
authors: Michael R
authors: MR
authors: Jacobs
authors: Cerexa, Inc., Oakland, CA, USA.
authors: Donald
authors: D
authors: Biek
authors: Cerexa, Inc., Oakland, CA, USA.
authors: Ian A
authors: IA
authors: Critchley
authors: JMI Laboratories, North Liberty, IA, USA.
authors: Ronald N
authors: RN
authors: Jones
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D024881:Drug Resistance, Bacterial; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D011008:Pneumococcal Infections / Q000453:epidemiology / Q000382:microbiology* / Q000517:prevention & control; D022242:Pneumococcal Vaccines / Q000008:administration & dosage*; D065288:Serogroup; D013296:Streptococcus pneumoniae / Q000145:classification* / Q000187:drug effects* / Q000276:immunology; D055815:Young Adult
chemical_list: C538862:13-valent pneumococcal vaccine; D000900:Anti-Bacterial Agents; D022242:Pneumococcal Vaccines
keywords: Pneumococci; Serotype; Vaccine