Genotyping and clarithromycin susceptibility testing of Mycobacterium avium subsp. hominissuis isolated in Tuscany, Italy

Infect Genet Evol. 2018 Nov:65:144-149. doi: 10.1016/j.meegid.2018.07.032. Epub 2018 Jul 25.

Abstract

Mycobacterium avium subsp. hominissuis (MAH) is a major cause of nontuberculous mycobacteria infection and the incidence of MAH infections is increasing in many countries. This study aimed at determining the VNTR-based genetic diversity and the susceptibility to clarithromycin of a collection of 71 MAH human strains isolated in the last seven years. The VNTR analysis, revealing 16 unique patterns and 8 clusters including a total of 55 isolates, showed that most MAH isolates displayed a close genetic relationship, indicating that the MAH genotypes are quite homogeneous in our geographical area. Clarithromycin showed strong antimicrobial activity against MAH isolates, as indicated by the high proportion (94.4%) of susceptible strains. No association between specific VNTR patterns and the clinical features or the MIC of clarithromycin was found.

Keywords: Clarithromycin; Molecular typing; Mycobacterium avium subsp. hominissuis; VNTR analysis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Anti-Bacterial Agents / pharmacology*
  • Child
  • Child, Preschool
  • Clarithromycin / pharmacology*
  • Female
  • Genotype
  • Humans
  • Infant
  • Italy / epidemiology
  • Male
  • Microbial Sensitivity Tests
  • Middle Aged
  • Minisatellite Repeats
  • Mycobacterium avium Complex / drug effects*
  • Mycobacterium avium Complex / genetics*
  • Mycobacterium avium Complex / isolation & purification
  • Mycobacterium avium-intracellulare Infection / epidemiology*
  • Mycobacterium avium-intracellulare Infection / microbiology

Substances

  • Anti-Bacterial Agents
  • Clarithromycin