Tellurite resistance: a putative pitfall in Corynebacterium diphtheriae diagnosis?

Abstract

Corynebacterium diphtheriae strains continue to circulate worldwide causing diphtheria and invasive diseases, such as endocarditis, osteomyelitis, pneumonia and catheter-related infections. Presumptive C. diphtheriae infections diagnosis in a clinical microbiology laboratory requires a primary isolation consisting of a bacterial culture on blood agar and agar containing tellurite (TeO3(2-)). In this study, nine genome sequenced and four unsequenced strains of C. diphtheriae from different sources, including three samples from a recent outbreak in Brazil, were characterized with respect to their growth properties on tellurite-containing agar. Levels of tellurite-resistance (Te(R)) were evaluated by determining the minimum inhibitory concentrations of potassium tellurite (K2TeO3) and by a viability reduction test in solid culture medium with K2TeO3. Significant differences in Te(R) levels of C. diphtheriae strains were observed independent of origin, biovar or presence of the tox gene. Data indicated that the standard initial screening with TeO3(2-)-selective medium for diphtheria bacilli identification may lead to false-negative results in C. diphtheriae diagnosis laboratories.

• Authors: Louisy Sanches dos Santos, Camila Azevedo Antunes, Daniel Martins de Oliveira, Lincoln de Oliveira Sant'Anna, José Augusto Adler Pereira, Raphael Hirata Júnior, Andreas Burkovski, Ana Luíza Mattos-Guaraldi
• Journal: Antonie van Leeuwenhoek (Antonie Van Leeuwenhoek) Vol. 108 Issue 5 Pg. 1275-9 (Nov 2015) ISSN: 1572-9699 [Electronic] Netherlands
• PMID: 26459339 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Anti-Bacterial Agents
• Bacterial Proteins
• Virulence Factors
• tellurite-resistance protein, Corynebacterium diphtheriae
• tellurous acid
• Tellurium

Topics

• Anti-Bacterial Agents (pharmacology)
• Bacterial Proteins (genetics)
• Corynebacterium diphtheriae (classification, drug effects, genetics)
• Diphtheria (diagnosis, microbiology)
• Drug Resistance, Bacterial (genetics)
• Humans
• Microbial Sensitivity Tests
• Phylogeny
• Tellurium (pharmacology)
• Virulence Factors (genetics)