Phenotypic and Genotypic Correlates of Penicillin Susceptibility in Nontoxigenic Corynebacterium diphtheriae, British Columbia, Canada, 2015–2018

Details

• Alternative Title:
  Emerg Infect Dis
• Personal Author:
  Zou, Jason ; Chorlton, Samuel D. ; Romney, Marc G. ; Payne, Michael ; Lawson, Tanya ; Wong, Anna ; Champagne, Sylvie ; Ritchie, Gordon ; Lowe, Christopher F.
• Description:
  In 2015, the Clinical and Laboratory Standards Institute (CLSI) updated its breakpoints for penicillin susceptibility in Corynebacterium species from <1 mg/L to <0.12 mg/L. We assessed the effect of this change on C. diphtheriae susceptibility reported at an inner city, tertiary care center in Vancouver, British Columbia, Canada, during 2015-2018 and performed whole-genome sequencing to investigate phenotypic and genotypic resistance to penicillin. We identified 44/45 isolates that were intermediately susceptible to penicillin by the 2015 breakpoint, despite meeting previous CLSI criteria for susceptibility. Sequencing did not reveal β-lactam resistance genes. Multilocus sequence typing revealed a notable predominance of sequence type 76. Overall, we saw no evidence of penicillin nonsusceptibility at the phenotypic or genotypic level in C. diphtheriae isolates from our institution. The 2015 CLSI breakpoint change could cause misclassification of penicillin susceptibility in C. diphtheriae isolates, potentially leading to suboptimal antimicrobial treatment selection.
• Subjects:
  Anti-Bacterial Agents Corynebacterium Diphtheriae Drug Resistance, Bacterial Genetic Association Studies Humans Microbial Sensitivity Tests Multilocus Sequence Typing Penicillins Whole Genome Sequencing
• Source:
  Emerg Infect Dis. 26(1):97-103
• Pubmed ID:
  31855139
• Pubmed Central ID:
  PMC6924910
• Document Type:
  Journal Article
• Place as Subject:
  British Columbia, Canada
• Volume:
  26
• Issue:
  1
• Collection(s):
  Emerging Infectious Diseases
• Main Document Checksum:
  urn:sha256:bc49c4c75bdd2c8a7e144725ed806d868e7bb3fa561f8d6758f53c1af1b3f987
• Download URL:
  https://stacks.cdc.gov/view/cdc/83907/cdc_83907_DS1.pdf
• File Type:
  [PDF - 764.42 KB ]