Emergence of Streptococcus pneumoniae serogroups 15 and 35 in nasopharyngeal cultures from young children with acute otitis media.

Abstract

BACKGROUND:

Surveillance of children with acute otitis media (AOM) for nasopharyngeal colonization with Streptococcus pneumoniae before, during and after the introduction of 7-valent pneumococcal conjugate vaccine (PCV7) indicated the near-complete elimination of PCV7 strains and the emergence of pneumococcal serotype 19A.

METHODS:

To determine effects of the introduction of 13-valent pneumococcal conjugate vaccine (PCV13) on pneumococcal nasopharyngeal colonization, we obtained nasopharyngeal cultures from 228 children 6 through 23 of age months presenting with a new episode of AOM during 2012 and 2013 and enrolled in an ongoing clinical trial of antimicrobial efficacy. All children had received at least 2 doses of PCV13. The S. pneumoniae isolates were subjected to serotyping and testing for antimicrobial susceptibility. We compared the findings with results obtained in 3 earlier studies.

RESULTS:

We found nasopharyngeal colonization with S. pneumoniae in 113 (50%) of the children with AOM. PCV7 and PCV13 serotypes accounted for 2% and 12%, respectively, of the pneumococcal isolates. Of the 14 PCV13 isolates, 8 were serotype 19A. Nonvaccine serotypes accounted for 69% of the isolates. Most frequently occurring were subtypes of serotype 15 (23%) and serotype 35B (9%). Overall, 33% of the isolates were penicillin nonsusceptible, a proportion not significantly different from proportions found in our 3 earlier studies (26%, 36% and 37%, respectively). Serotypes 15 and 35B accounted for 51% of penicillin-nonsusceptible isolates.

CONCLUSIONS:

Expansion of contents of pneumococcal vaccine administered to children is followed by not-fully-predictable changes in nasopharyngeal pneumococcal colonization. Continued surveillance is required to help inform future vaccine development.

• Authors: Judith M Martin, Alejandro Hoberman, Jack L Paradise, Karen A Barbadora, Nader Shaikh, Sonika Bhatnagar, Timothy Shope, Stan L Block, Mary Ann Haralam, Marcia Kurs-Lasky, D Kathleen Colborn, Michael Green
• Journal: The Pediatric infectious disease journal (Pediatr Infect Dis J) Vol. 33 Issue 11 Pg. e286-90 (Nov 2014) ISSN: 1532-0987 [Electronic] United States
• PMID: 24911895 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)

Chemical References

• 13-valent pneumococcal vaccine
• Pneumococcal Vaccines

Topics

• Acute Disease
• Carrier State (microbiology)
• Disk Diffusion Antimicrobial Tests
• Female
• Humans
• Infant
• Male
• Nasopharynx (microbiology)
• Otitis Media (microbiology)
• Penicillin Resistance
• Pneumococcal Infections (microbiology)
• Pneumococcal Vaccines
• Serogroup
• Serotyping
• Streptococcus pneumoniae (classification, isolation & purification)