Emerging Infectious Diseases (Aug 2017)

Molecular Characterization of Corynebacterium diphtheriae Outbreak Isolates, South Africa, March–June 2015

  • Mignon du Plessis,
  • Nicole Wolter,
  • Mushal Allam,
  • Linda de Gouveia,
  • Fahima Moosa,
  • Genevie Ntshoe,
  • Lucille Blumberg,
  • Cheryl Cohen,
  • Marshagne Smith,
  • Portia Mutevedzi,
  • Juno Thomas,
  • Valentino Horne,
  • Prashini Moodley,
  • Moherndran Archary,
  • Yesholata Mahabeer,
  • Saajida Mahomed,
  • Warren Kuhn,
  • Koleka Mlisana,
  • Kerrigan McCarthy,
  • Anne von Gottberg

DOI
https://doi.org/10.3201/eid2308.162039
Journal volume & issue
Vol. 23, no. 8
pp. 1308 – 1315

Abstract

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In 2015, a cluster of respiratory diphtheria cases was reported from KwaZulu-Natal Province in South Africa. By using whole-genome analysis, we characterized 21 Corynebacterium diphtheriae isolates collected from 20 patients and contacts during the outbreak (1 patient was infected with 2 variants of C. diphtheriae). In addition, we included 1 cutaneous isolate, 2 endocarditis isolates, and 2 archived clinical isolates (ca. 1980) for comparison. Two novel lineages were identified, namely, toxigenic sequence type (ST) ST-378 (n = 17) and nontoxigenic ST-395 (n = 3). One archived isolate and the cutaneous isolate were ST-395, suggesting ongoing circulation of this lineage for >30 years. The absence of preexisting molecular sequence data limits drawing conclusions pertaining to the origin of these strains; however, these findings provide baseline genotypic data for future cases and outbreaks. Neither ST has been reported in any other country; this ST appears to be endemic only in South Africa.

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