title: 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.affiliation: Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil. louisysanchesuerj@gmail.com.
authors.forename: Louisy Sanches
authors.initials: LS
authors.lastname: dos Santos
authors.affiliation: Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil. azevedoantunes.camila@gmail.com.|Faculdade de Ciências Médicas, Universidade do Estado do Rio de Janeiro - UERJ, Av. 28 de Setembro, 87 - Fundos, 3º andar. Vila Isabel, Rio De Janeiro, RJ, CEP: 20 551-030, Brazil. azevedoantunes.camila@gmail.com.|Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany. azevedoantunes.camila@gmail.com.
authors.forename: Camila Azevedo
authors.initials: CA
authors.lastname: Antunes
authors.affiliation: Faculdade de Ciências Médicas, Universidade do Estado do Rio de Janeiro - UERJ, Av. 28 de Setembro, 87 - Fundos, 3º andar. Vila Isabel, Rio De Janeiro, RJ, CEP: 20 551-030, Brazil. daniel.0246@gmail.com.
authors.forename: Daniel Martins
authors.initials: DM
authors.lastname: de Oliveira
authors.affiliation: Faculdade de Ciências Médicas, Universidade do Estado do Rio de Janeiro - UERJ, Av. 28 de Setembro, 87 - Fundos, 3º andar. Vila Isabel, Rio De Janeiro, RJ, CEP: 20 551-030, Brazil. lincolnsantanna2013@gmail.com.
authors.forename: Lincoln de Oliveira
authors.initials: Lde O
authors.lastname: Sant'Anna
authors.affiliation: Faculdade de Ciências Médicas, Universidade do Estado do Rio de Janeiro - UERJ, Av. 28 de Setembro, 87 - Fundos, 3º andar. Vila Isabel, Rio De Janeiro, RJ, CEP: 20 551-030, Brazil. josep@uerj.br.
authors.forename: José Augusto Adler
authors.initials: JA
authors.lastname: Pereira
authors.affiliation: Faculdade de Ciências Médicas, Universidade do Estado do Rio de Janeiro - UERJ, Av. 28 de Setembro, 87 - Fundos, 3º andar. Vila Isabel, Rio De Janeiro, RJ, CEP: 20 551-030, Brazil. hirata@uerj.br.
authors.forename: Raphael
authors.initials: R
authors.lastname: Hirata Júnior
authors.affiliation: Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany. andreas.burkovski@fau.de.
authors.forename: Andreas
authors.initials: A
authors.lastname: Burkovski
authors.affiliation: Faculdade de Ciências Médicas, Universidade do Estado do Rio de Janeiro - UERJ, Av. 28 de Setembro, 87 - Fundos, 3º andar. Vila Isabel, Rio De Janeiro, RJ, CEP: 20 551-030, Brazil. guaraldi@uerj.br.
authors.forename: Ana Luíza
authors.initials: AL
authors.lastname: Mattos-Guaraldi
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics; D003353:Corynebacterium diphtheriae / Q000145:classification / Q000187:drug effects* / Q000235:genetics; D004165:Diphtheria / Q000175:diagnosis* / Q000382:microbiology*; D024881:Drug Resistance, Bacterial / Q000235:genetics; D006801:Humans; D008826:Microbial Sensitivity Tests; D010802:Phylogeny; D013691:Tellurium / Q000494:pharmacology*; D037521:Virulence Factors / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D037521:Virulence Factors; C000605006:tellurite-resistance protein, Corynebacterium diphtheriae; C026660:tellurous acid; D013691:Tellurium
keywords: Corynebacterium diphtheriae; Diphtheria; Invasive infections; Laboratory diagnosis; Telurite-resistance