Resistance to bacitracin in Streptococcus pyogenes from oropharyngeal colonization and noninvasive infections in Portugal was caused by two clones of distinct virulence genotypes

• Published in: FEMS microbiology letters Vol. 296; no. 2; pp. 235 - 240
• Main Authors: Pires, Renato, Rolo, Dora, Mato, Rosario, Feio de Almeida, João, Johansson, Christina, Henriques-Normark, Birgitta, Morais, Ana, Brito-Avô, António, Gonçalo-Marques, José, Santos-Sanches, Ilda
• Format: Journal Article
• Language: English
• Published: Oxford, UK Oxford, UK : Blackwell Publishing Ltd 01-07-2009; Blackwell Publishing Ltd; Wiley-Blackwell; Oxford University Press
• Subjects: Anti-Bacterial Agents - pharmacology; Bacitracin; Bacitracin - pharmacology; Bacterial Proteins - genetics; Bacterial Typing Techniques; Bacteriology; Biological and medical sciences; Carrier State - microbiology; Cluster Analysis; Colonization; DNA Fingerprinting; Drug Resistance, Bacterial; Electrophoresis, Gel, Pulsed-Field; Enterococcus faecalis; Exotoxins; Fundamental and applied biological sciences. Psychology; Genotype; Genotypes; Humans; infection; Infections; Lincosamides - pharmacology; Macrolides - pharmacology; Medicin och hälsovetenskap; Microbiology; Miscellaneous; Oropharynx - microbiology; Pathogens; Pharyngitis; Pharyngitis - microbiology; Portugal; resistance; Strains (organisms); Streptococcal Infections - microbiology; Streptococcus infections; Streptococcus pyogenes; Streptococcus pyogenes - classification; Streptococcus pyogenes - drug effects; Streptococcus pyogenes - genetics; Streptococcus pyogenes - isolation & purification; Streptogramin B - pharmacology; Superantigens; Tonsillitis; Tonsillitis - microbiology; Virulence; Virulence Factors - genetics; Southern Europe; Portugal; Europe; infection; virulence; colonization; bacitracin; resistance; Cyclic peptides; Virulence; Genotype; Bacitracin; Resistance; Streptococcaceae; Antibiotic; Polypeptide; Molecular epidemiology; Bacteria; Micrococcales; Streptococcus pyogenes; Antibacterial agent
• ISSN: 0378-1097; 1574-6968; 1574-6968
• DOI: 10.1111/j.1574-6968.2009.01642.x

During 2000-2007 in Lisbon, we identified 45 bacitracin-resistant Streptococcus pyogenes isolates among 1629 isolates: 24 from oropharyngeal healthy carriers (out of 1026), 21 from patients with noninvasive infections (out of 559) and zero from invasive infections (out of 44). Forty-four of those isolates, mainly of colonization, are low-level bacitracin-resistant members of the cMLSB-macrolide-resistant and tetracycline-susceptible emm28/ST52 clone previously detected in Europe, but only among clinical samples. One high-level bacitracin-resistant isolate, associated with a tonsillitis/pharyngitis episode, is cMLSB-macrolide-resistant and tetracycline-resistant member of the emm74/ST120 lineage, which was not previously known to include bacitracin-resistant isolates. The bcrABDR operon encoding an ATP-binding cassette transporter in Enterococcus faecalis was not detected among these bacitracin-resistant S. pyogenes strains. Virulence profiling indicated that genes coding for exotoxins and superantigens seem to be clone specific. This study provides an increased knowledge about specific bacitracin-resistant S. pyogenes strains, which may be useful in future investigations aiming to understand the mechanism(s) leading to bacitracin resistance and the cause(s) for differences in colonization and/or dissemination potential.