Molecular characterization of Shigella spp. from patients in Gabon 2011-2013

Trans R Soc Trop Med Hyg. 2015 Apr;109(4):275-9. doi: 10.1093/trstmh/tru175. Epub 2014 Nov 20.

Abstract

Background: Shigella spp. dysentery is widespread in developing countries; the incidence is particularly high in children between 1-2 years of age. In sub-Saharan Africa, there is a paucity of epidemiological data on Shigella spp., with possible negative consequences for recognition and correct treatment choice for this life-threatening bacterial infection. We therefore characterized Shigella spp. isolates from Gabon.

Methods: The antimicrobial resistance, virulence factors, genotypes and mobile genetic elements of Shigella isolates (29 S. flexneri; 5 S. boydii; 3 S. sonnei) from a retrospective strain collection were analyzed.

Results: High resistance rates were found for gentamicin and tetracycline (100%, 37/37), cotrimoxazole (92%, 34/37) and ampicillin (84%, 31/37). All isolate harbored ial and ipaH; no isolate produced Shiga toxins (stx1/2); enterotoxins (set1A/B) were only found in S. flexneri (n=19). Multilocus sequence types (MLST) clustered with global clones. A high prevalence of atypical class 1 integrons harboring blaOXA30 and aadA1 were detected in S. flexneri, while all S. sonnei carried class 2 integrons.

Conclusions: There is a strong link of Gabonese Shigella spp. isolates with pandemic lineages as they cluster with major global clones and frequently carry atypical class 1 integrons which are frequently reported in Shigella spp. from Asia.

Keywords: Africa; Drug resistance; Gabon; Genotype; Shigella; Virulence.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Bacterial Agents / therapeutic use*
  • Child, Preschool
  • DNA, Bacterial / isolation & purification
  • Drug Resistance, Multiple, Bacterial / genetics*
  • Drug Resistance, Multiple, Bacterial / immunology
  • Dysentery, Bacillary / epidemiology
  • Dysentery, Bacillary / immunology
  • Female
  • Gabon / epidemiology
  • Humans
  • Infant
  • Integrons
  • Male
  • Microbial Sensitivity Tests
  • Multilocus Sequence Typing
  • Retrospective Studies
  • Shigella / genetics*
  • Shigella / isolation & purification
  • Shigella dysenteriae / genetics
  • Shigella flexneri / genetics
  • Shigella sonnei / genetics

Substances

  • Anti-Bacterial Agents
  • DNA, Bacterial