Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Case Reports
. 2016 Apr 12:4:56-8.
doi: 10.1016/j.idcr.2016.04.001. eCollection 2016.

Nonencapsulated Streptococcus pneumoniae as a cause of chronic adenoiditis

Cheshil Dixit  1 , Lance E Keller  1 , Jessica L Bradshaw  1 , D Ashley Robinson  1 , Edwin Swiatlo  1 , Larry S McDaniel  1
Affiliations
Case Reports

Nonencapsulated Streptococcus pneumoniae as a cause of chronic adenoiditis

Cheshil Dixit et al. IDCases. .

Abstract

Streptococcus pneumoniae is an important human pathogen. To cause disease, it must first colonize the nasopharynx. The widespread use of pneumococcal-conjugate vaccines which target the capsular polysaccharide has led to decreased nasopharyngeal carriage of vaccine serotypes, but a concomitant increase in carriage of non-vaccine serotypes and nonencapsulated S. pneumoniae (NESp). Some NESp express pneumococcal surface protein K (PspK), a virulence factor shown to contribute to nasopharyngeal colonization. We present the case of a child with chronic adenoiditis caused by a PspK(+) NESp. We tested the pneumococcal isolate, designated C144.66, for antimicrobial resistance, the presence of the pspK gene and the expression of PspK. Sequence typing and genome sequencing were performed. C144.66 was found to be resistant to erythromycin and displayed intermediate resistance to penicillin and trimethoprim/sulfamethoxazole. C144.66 has the pspK gene in place of the capsule locus. Additionally, PspK expression was confirmed by flow cytometry. NESp are a growing concern as an emerging human pathogen, as current pneumococcal vaccines do not confer immunity against them. An inability to vaccinate against NESp may result in increased carriage and associated pathology.

Keywords: Chronic adenoiditis; Nonencapsulated Streptococcus pneumoniae (NESp); Pneumococcal surface protein K; Streptococcus pneumoniae.

PubMed Disclaimer

Figures

Fig. 1
Fig. 1
PCR analysis of C144.66. PCR analysis of strains MNZ11 (cpsA−, pspK+) D39 (cpsA+, pspK−), and C144.66 (cpsA−, pspK+), respectively, for cpsA (lanes 2–4) and pspK (lanes 5–7). Lane 1 is a 1-Kb DNA ladder.
Fig. 2
Fig. 2
Flow cytometry for the presence of PspK. For analysis 1 × 107 log phase pneumococci were incubated with a mouse anti-PspK antiserum. A biotinylated anti-mouse secondary antibody was detected by streptavidin conjugated to Alex Flour 488. A representative histogram is shown. The negative control is MNZ85 which lacks PspK.
Fig. 3
Fig. 3
Colonization and ascension of C144.66 in a murine model. After intranasal inoculation of C144.66, colonization was achieved in all mice. Ascension into the middle ear occurred in two of the five mice. The dash line is the lower limit of detection.
See this image and copyright information in PMC

References

    1. Kaur R., Adlowitz D.G., Casey J.R., Zeng M., Pichichero M.E. Simultaneous assay for four bacterial species including Alloiococcus otitidis using multiplex-PCR in children with culture negative acute otitis media. Pediatr Infect Dis J. 2010;29:741–745. - PMC - PubMed
    1. Pelton S.I., Hammerschlag M.R. Overcoming current obstacles in the management of bacterial community-acquired pneumonia in ambulatory children. Clin Pediatr (Phila) 2005;44:1–17. - PubMed
    1. Musher D.M. Infections caused by Streptococcus pneumoniae: clinical spectrum, pathogenesis, immunity, and treatment. Clin Infect Dis. 1992;14:801–807. - PubMed
    1. Tan T.Q. Pediatric invasive pneumococcal disease in the United States in the era of pneumococcal conjugate vaccines. Clin Microbiol Rev. 2012;25:409–419. - PMC - PubMed
    1. Huang S.S., Platt R., Rifas-Shiman S.L., Pelton S.I., Goldmann D., Finkelstein J.A. Post-PCV7 changes in colonizing pneumococcal serotypes in 16 Massachusetts communities, 2001 and 2004. Pediatrics. 2005;116:e408–e413. - PubMed

Publication types

LinkOut - more resources